I 195 6 py 1 CONCRETE SILOS Silo a.(\d Dfeiry Bafrv Arca-dyDaiiry Fa^rm La>ke Forest.lll. A Booklet of Practical Information Prepared es- pecially for the Farmer and Rural Contractor. PUBLISHED B UNIVERSAL PORTLAND CEMENT CO CHICAGO PITTSBURG Copyright, 1911 by Universal Portland Cement Co. Chicago — Pittsburg Concrete Silos A BOOKLET OF PRACTICAL INFORMATION FOR THE FARMER AND THE RURAL CONTRACTOR Prepared by the INFORMATION BUREAU UNIVERSAL PORTLAND CEMENT CO. M Published by UNIVERSAL PORTLAND CEMENT CO. CHICAGO — PITTSBURG First Edition 1911 Table of Contents ^ 0) V ^ SILOS AND SILAGE Definitions 9 The Theory of Silage. 10 Silage Crops 10 The Advantages of Silage. 10 Dry Matter and Digestible Nutrients in Silage 12 Effect of Silage on the Flavor of Milk. 13 Effect on Cattle of a Silage Ration 13 CAPACITY, DIMENSIONS, AND LOCATION OF THE SILO Capacity for a Given Number of Cattle (Example) 14 Table of Capacities of Round Silos in Tons. 15 Economical Diameter 16 Height. 16 Location 17 FILLING THE SILO— USING OFF SILAGE When to Harvest 18 Harvesting the Crop. 18 The Cutter 18 Elevating and Distributing. , 18 Economy of Filling the Silo Rapidly 19 Wetting the Silage. 19 Cost of Filling 20 Table Showing the Cost of Filling Fifty-nine Concrete Silos. 44 Cost of Silage 21 Using Off the Silage. 21 ADVANTAGES OF CONCRETE AS A SILO MATERIAL Fireproof Construction 23 George Pulling's Silo. 23 A. B. Main's Silo 24 The Element of Waste. 26 The Effect of Freezing 26 Concrete Silos in the South. 29 WHAT IT COSTS TO BUILD A CONCRETE SILO Table showing the Cost of 78 Monolithic and 30 Block Silos 31 Time Required to Construct Concrete Silos. 33 A Comparison of the Monolithic and Block Types 33 BUILDING THE SILO Contract Work 34 Work Under Hired Foreman. 34 Work Under Home Supervision 35 Co-operation in Silo Work. 35 FOUNDATIONS Laying Out the Work 36 Excavating. 36 Placing the Concrete , 36 Imbedding Reinforcing Rods. 36 Table of Materials for the Footings, and Floor 37 ©CI.A29775I UNIVERSAL PORTLAND CEMENT CO. 5 ^ MONOLITHIC SILOS ^ Definition of "Monolithic" 39 ^ HOME MADE SILO FORMS i> Description of Forms 39 Table of Materials for Forms. 43 ^ Cost 43 Care in Bracing Supports. 43 Importance of a Smooth Wall 43 f. \^_ Greasing the Forms. 46 DOORWAYS Continuous Doorways 46 Frames and Doors. 46 Erecting and Anchoring Frames 47 Non-continuous Doorways. 47 Doorway Form and Frame 48 Doors. 49 CONSTRUCTING THE SILO WALLS Tables of Materials 51 Moving Up Forms for the Next Course. 51 Height of Wall at Each Filling 54 Labor Required. 54 Reinforcing '. 54 Spacing of Rods — Example. 54 Reinforcing Tables 54 Purchasing Reinforcing Rods. 54 Hoisting Materials 55 COMMERCIAL MONOLITHIC SILO SYSTEMS Polk System 57 New Enterprise System. 58 Angevine System 59 C. A. Anderson's Forms 60 McCoy Forms 61 CONCRETE BLOCK SILOS Popularity of Hollow Concrete Blocks 62 Examining Blocks. 62 Laying the Blocks 62 The Mortar. 63 Reinforcing — Example 63 Reinforcing Tables. 64 Table of Blocks Required 65 Recesses for Reinforcing Rod. 66 Continuous Door Frames 66 Doors. 66 HOME MADE BLOCKS List of Block Machine Manufacturers 68 Home Made Mold. 69 Size of Block 69 CONCRETE SILOS COMMERCIAL CONCRETE BLOCK SILOS The Perfect Silo 70 The Zeeland Silo. 72 THE CHUTE Size of Chute , • 73 Foundation. 73 Monolithic Chutes 73 Block Chutes. 73 WATER SUPPLY TANK Size of Tank 76 Planning for the Tank. 76 Reinforcing Diagram 77 Table of Capacities of Tanks. 77 The Floor 78 Table of Materials for the Floor. 78 Continuing Walls Above the Floor 79 Reinforcing — Example. 80 Piping and Overflow 80 THE CONCRETE ROOF The Cornice 81 Roof Framing. 82 Placing the Reinforcing 82 Concreting. 84 Table of Materials 85 Monolithic Roofs for Hollow Block Silos. 85 INDEX TO TABLES Table Title Page A Dry Matter and Digestible Nutrients in Silage. 12 B Quantity of Silage Required and Economical Diameter for the Dairy Herd. 14 C Capacity of Round Silos in Tons. 15 D Cost of Filling 59 Concrete Silos. 44-45 E Cost of 78 Monolithic Concrete Silos. 31 F Cost of 30 Concrete Block Silos. 32 G Materials for Silo Footings and Floors. 37 H Materials for Home Made Silo Forms. 43 I Cubic Yards of Concrete in Silo Walls. 51 J Cement, Sand and Gravel Required for Silo Walls. 52 K Size and Spacing of Reinforcing Rods in Monolithic Silo Walls. 53 L Block Required for Walls of a Concrete Block Silo. 64 M Size of Reinforcing Rods for Concrete Block Silo. 65 N Capacities of Water Supply Tanks. 77 O Materials and Reinforcing for Tank Floors. 78 IN preparing data for the booklet, the Information Bureau of the Universal Portland Cement Company investigated during the Spring of 1911, one hundred and ten monolithic and block silos located in the North Central States. Methods of silo construction and opera- tion were carefully studied and data on the actual cost and labor required, and other important information was obtained. Valuable assistance was received from a number of sources, particularly from the bulletins of the Department of Agriculture and the State Experi- ment Stations, several paragraphs from which have been used ver- batim. The reader seeking further information on the subject of silage and silo construction will find in the following pamphlets a compre- hensive course of instruction : Cement Silos — Farmers' Bulletin No. 405, U. S. Department of Agri- culture. Silos and Silage — Farmers' Bulletin No. 32, U. S. Department of Agriculture. Cost of Filling Silos — Farmers' Bulletin No. 292 U. S. Department of Agriculture. Cement Silos in Michigan — Bulletin No. 255, Michigan State Experi- ment Station, East Lansing, Michigan. Silage and the Construction of Modern Silos — Bulletin No. 83, Wis- consin Agricultural Experiment Station, Madison, Wisconsin. The Silo — Monthly Bulletin No. 2, Volume 6, Missouri State Board of Agriculture, Columbia, Missouri. Silage and Silo Construction — Bulletin No. 4, Vol. II, Kansas State Agricultural College, Manhattan, Kansas. Silos and Silage in Maryland — Bulletin No. 129, Maryland Agricul- tural Experiment Station, College Park, Maryland. The Silo and Silage in Indiana — Bulletin No. 40, Purdue Agricultural Experiment Station, LaFayette, Indiana. Soiling Crops, Silage and Roots — Bulletin No. 9, Series II, College of Agriculture, Cornell University, Ithaca, New York. Modern Silage Methods — Silver Manufacturing Company, Salem, Ohio. (Farmers' Bulletins published by the Department of Agriculture may be obtained by addressing Joseph A. Arnold, Editor-in-Chief, Bureau of Publications, Department of Agriculture, Washington, D. C.) Outside of the publications mentioned above, "Modern Silage Methods," published by the Silver Manufacturing Company, of Salem, Ohio, contains much valuable information which the silo builder and farmer should have. UNIVERSAL PORTLAND CEMENT CO. 9 Concrete Silos Silos and Silage HISTORY will record the Nineteenth Century a& an era of un- precedented agricultural progress. During the first fifty years the steel plow, the cultivator, and the harvester came into use, and succeeding decades brought the tractor, the gasoline engine, the great irrigation and dry farming projects and the silo — the latter destined to become one of the most potent factors in American farm economy. Conservation is the watchword of the present century. With the farmer the question is not only "How much corn can I raise?" but also "How can I get the most out of my corn?" * * * It is this spirit which has dotted the dairy and stockraising sections of the country with silos, from Maine to Oregon, and from the Gulf to the Canadian Provinces, until, as a re- cent writer has put it, "A good dairy community can be judged by the number of silos on the horizon just as an oil district may be known by the number of derricks in use." The silo is one of the true con- servators of the nation's resources. Several state experiment stations have estimated that 40 per cent of the value of corn is in the stalks, al- . „ii r u-u* jTiU 1 j. Fig. 1. Two 60-foot Polk silos, being con- mOSt all Of Which IS saved if the lat- stru cted for Mr. Peter Emge. Fort Branch. ter are placed in a silo. When other ind., showing forms in position for last crops are used the saving is almost flllmg - as great. The results have enabled stock and dairy men to keep more cattle on the same sized farms, as well as to maintain the herds in better health, and increase the milk flow. Several Southern Michigan farmers keep 20 head of dairy cattle on 20 to 30 acres by feeding them from the silo all year round, and having but small pastures. In such cases silage has been found equal to June grass, and entirely without harmful effect, even when used 365 days out of the year. Definitions: — The silo is an air-tight chamber or tank often wholly above ground, but very frequently having as much as one-third of its capacity below the surface. In its original form the silo was merely a large pit, being entirely below ground. The function of the silo is to preserve green succulent food which is thus available during summer droughts when pastures are used up, and during the winter when dry feed alone results in shrinking milk flows and checked srrowth in fattening: stock. 10 CONCRETE SILOS The term "ensilage," or more properly "silage," is used to denote the fodder preserved in the silo. In the corn belt States silage is usually made from corn, while in other parts of the country sorghum, pea vines, alfalfa, clover, soy beans and cow peas, supplement corn to a considerable extent, or are some- times substituted for it. The Theory of Silage : — Silage is kept in the silo very much as fruit, vegetables and other articles of human food are preserved in air- tight cans. The germs which cause fermentation can grow only when supplied with oxygen, and if air is kept from the silage it can be pre- served for an indefinite period. As soon as the silo is filled, fermenta- tion begins, continuing until the supply of oxygen is exhausted. If the silage is well packed, and neither too green nor too ripe, it will continue to ferment for but a short time, and will be practically uniform below the top coating. The sweet- ness of the food depends upon the stage to which the fermentation was carried, and the subsequent exclu- sion of air. Sour silage is not as wholesome as sweet silage, nor will the cattle partake of it so freely. The best silage can only be made in a practically air-tight silo. Silage Crops : — Corn is undoubtedly the best silage crop wherever it will grow to full maturity. The yield per acre is heavy, the losses small, and the cost of harvesting lower than for most other crops. Sweet corn is not as desirable for silage because the sugar tends to produce excessive acid. Sweet sorghums are objectionable for the same reason, but those of the non-saccharine or kaffir-corn variety make good silage and will undoubtedly be used largely in the semi- arid portions of the southwest, where sorghum is a better crop than corn. Alfalfa and clover both make good silage but are little used as yet. Pea vines are commonly used where they can be obtained as a cannery by-product, and make excellent silage when mixed or used in conjunction with corn. The Advantages of Silage : — Someone has compared the difference between silage and dry feed to that "between a juicy, ripe apple and the green dried fruit." Because of its succulence, silage has a beneficial effect on the digestion of the animals and they become very fond of it. The economy of storing silage is a feature which appeals at once to Fig. 2. J. C. Eastman's concrete silo, Crown Point, Ind. Height, 41 feet; Diameter, 18 feet. Capacity, 238 tons. N. L. Smith, Crown Point, architect. UNIVERSAL PORTLAND CEMENT CO. 11 the average farmer. Two and one-half to three tons of silage is equivalent in feeding value to a ton of hay and may be stored in one-half to two-thirds the space occupied by the latter. As already mentioned in a previous paragraph, more cattle can be kept on a given amount of land with silage, and there is the additional advan- tage that after the crop is in the silo the feeder is not dependent to any extent whatever upon weather con- ditions. The Missouri Farmer's Bulletin No. 11 sums up the advan- tage of silage as follows : 1. Silage keeps young stock thrifty and growing all winter, 2. It produces fat beef more cheap- ly than does dry feed. 3. It enables cows to produce milk and butter more economically. 4. Silage is more conveniently handled than dry fodder. 5. The silo prevents waste of corn stalks, which contain about one- third the food value of the entire crop. 6. There are no aggravating corn stalks in the manure when silage is fed. 7. The silo will make palatable food of stuff that would not otherwise be eaten. 8. It enables a large number of ani- mals to be maintained on a given number of acres. 9. It enables the farmer to preserve 'food which matures at a rainy time of the year, when drying would be next to impossible. 10. It is the most economical method of supplying food for the stock during the hot, dry periods in summer, when the pasture is short. In a recent circular, Mr. Chris De Jonge, of Zeeland, Michigan, has written the following as an example of concrete silo economy : "You can grow only two tons of hay on one acre and ten tons of ensilage on the same acre. Two tons of hay at $12.00 per ton will bring $24.00. Ten tons of ensilage at $4.00 will bring $40.00. That is $16.00 per acre in favor of the ensilage. One ton of hay will cost $1.50 to cut and bring into the barn, and one ton of ensilage will cost only 60 cents to cut and put in the silo. If you feed one cow 40 pounds of ensilage per day, it takes nearly eight tons to feed her one year. So if you only get eight tons of ensilage per acre you can feed one cow one year from it, or two cows one-half year off one acre. If you pasture your cows during the summer, six months, it takes two acres to pasture one cow. So by having a silo you keep four times as many cows as you do without a silo. Fig. 3. Monolithic silo, nearly completed by the Polk -Genung- Polk system, on the farm of John Creighton, Geneva, 111. W. H. Warford, Contractor 12 CONCRETE SILOS M •*H J CO pq PI < 4J h u 3 C .5? •3 Ph w u w o O *H CM C^ M3 ON CO co in On m 00 CO 00 00 O On in CO ■-< r-i oo m in cm o in CM CM CM CO CM CM o o CM CM O U rt o C C3 en en ft ,Q ^1 c Rj >, i* in 1h o o as o O U CO pq L) be a u ct a, »CMr^^\o^r^cMc>TroNin^^coc*u^^t>coot^co* z <£.in £}°}i£ CM CM CM CM CM CM o\coi^cm\ooio©uioioo^^^cmsocmoo^q\ocmo\;*»- | £; SvO\oK^OOo6^C*0©^^CMOCM^t^Os^coOOO^cp^pOpCM;J <£ t>. 00 On © CM CO Tf u^ 00 O ^ fo^ ^O^ On © -f CO "J Vh ,-* i-c CM CM CM CM CM CM CM CO CO CO CO co CO CO Tf r(- ■* ■*)- K'rTs ^^^^VO^OOC^O^CMCO^iOVO^OOgsp^CMCO^^O^OOOsO iCMCMCMCM^CMCMCMCMCocococOCOCOcOCOCoco^^Tfrt-^^^^^'*^ 16 CONCRETE SILOS Diameter: — After determining the approximate amount of silage required, the most economical diameter for the silo must be decided on. The diameter should depend upon the number of cattle to be fed, and at least 2 inches of silage must be removed each day to pre- vent spoiling. The diameter required for various numbers of cows is about as given in the two right columns of table "B." Dairy cows eat from 30 to 40 pounds of silage per day, which amount equals about one cubic foot. Horses and mules eat about one-half and sheep about one-third as much as cows. Height: — The height of the silo must be such that the required ca- pacity may be obtained with the most economical diameter, providing, however, that the height does not run above 40 feet for the small dia- meters, and 50 feet for the large diameters, according to the limitations of table "C." Extremely high silos are not as accessible and are more difficult to fill than less lofty structures. For these reasons two silos are often preferred. The high silo of small diameter has less waste than the silo of larger diameter, and the greater weight of silage in high silos reduces the amount of tramping necessary and silos of smaller diameter allow greater variation in the size of the herd without loss from spoiling of silage. Example : — Required, a silo of sufficient capacity to feed 30 cows for a period of 180 days. Referring to table "B," run down the ver- -f*^" ' ^ J ~-A Fig. 6. Concrete stave silo at the University of Minnesota, St. Paul. The staves are 24 inches long and 8 inches in width. The concrete stave idea is a good one, if properly carried' out. On this particular silo the re-inforcing bands were incorrectly spaced, and the staves made too thin, which resulted in cracking several staves. The silo has a remarkably smooth interior, and very little silage is spoiled. It has one fault in common with the wooden stave silos, however, in that the steel hoops are exposed to rust. UNIVERSAL PORTLAND CEMENT CO. 17 tical column headed "Number of Dairy Cows" to 30. Run- ning across horizontally, it will be seen that for ISO clays' feed, 108 tons of silage will be needed, and that for a silo of this capacity, the diameter should be 16 feet. Referring to table "C," run down the column headed "16 feet" to the numbers nearest the estimated capac- ity (108 tons). For a 16-foot silo of 109 tons capacity the height will be 28 feet. Location LOCATION: — The silo should be placed where it will be con- venient for filling, and if possible, where the ground is firm, so there will be no danger of settlement. Silage is heavy feed, and therefore an unhandy arrangement with respect to the feeding alley always increases greatly the work connected with feeding. One of the best arrangements for con- venient feeding is to place the silo or silos at the end of the alley. If this be done, a silage car can be used to advantage without having sharp corners to turn. The silo should not be surrounded by build- ings and pens in such a way as to interfere with filling. Obstructions hinder the work greatly, increasing the cost to the owner. In most cases where the ground is soft, it will pay to carry the foun- dation down to a firm bottom, or to fill in with gravel. If it is impracti- cal to go down to solid earth, the footings must be increased to at least twice the breadth recom- mended on page 36, and more if there is the least uncertainty. In parts of the country where winters are severe, there is an ad- vantage in placing the silo on the south side of the barn, where it will be protected from the north winds. In the past quite a large number of silos have been built within the barn, but this practice is not recommended for several reasons. Such silos are inconvenient to fill, and silo odors are objectionable in the barn, for unless great caution is taken, the milk is apt to be con- taminated. Perhaps the most common fault made in locating silos is to get them too far away from the barn. In cases where this distance is made too great, the only way of remedying the situation is to build a room connecting the silo with the barn, thus incurring needless expense and increasing the distance to haul the silage. The distance from silo doors to barn need never be over 4 feet, which is sufficient for a chute of the ordinary size. Fig. 7. Monolithic silo built by Mr. Albert Schweitzer. Roberts, Wis., with the Farmers Institute Silo Farms. The cost of this silo complete was $194.70, and it has a capacity of 167 tons, making the cost per ton less than $1.20. 18 CONCRETE SILOS Filling the Silo WHEN TO HARVEST:— The corn should be cut while the stalks are still green, but after the lower leaves have begun to dry. At this stage the kernels have hardened or "glazed" on the outside, but are yet in the "dough" condition in the middle. If cut too green the silage will lack protein, sugar and other nutritive elements, and will contain an excess of moisture, generally making it sour. If too matured, it will be dry and unpalatable, with the fibre very prominent. In this condition it con- tains less nutriment, is relished less by the cattle, and is apt to mold or "fire-fang," causing it to be greatly damaged. Corn dried out in the shock makes poor silage unless wet when put into the silo. Harvesting the Crop : — The harvesting of corn or sorghum for the silo may be done by hand with the ordinary corn knife, but the corn harvester or binder is the imple- ment almost universally used for this work. In some sections of the country corn has been cut with a sled equipped with saw-like knives projecting from both sides, but this method of harvesting is not now used to any great extent. Except where the corn has fallen down badly, as was the case in some sec- tions of Michigan in 1910, the binder can be used to advantage. It not only saves time in cutting the crop, but also binds it into bundles which are easier to load on the wagon and feed into the cutter than the loose corn. The Cutter: — Corn is sometimes placed in the silo uncut, but this practice is not to be recommended because the stalks will not pack closely, and the resulting air spaces cause excessive fermentation. The material is not as easily handled as cut silage, nor is it as eco- nomical to feed. The crop must be cut up fine for best results and when corn is used the entire plant, including ears, should be fed into the cutter. Although practice varies greatly, it is safe to say that corn for the silo should be cut one-half inch or even shorter. It is a well-known fact that corn will pack better in the silo the shorter it is cut, increasing the capacity to a considerable extent. Cattle like short silage better and will eat it up cleaner. Elevating and Distributing: — From the cutter the silage is ele- vated by a blower or conveyor, and deposited in a chute or automatic distributer. One or two men are required within the silo while it is Fig. 8. Mon jlithic silo on L. A. Crawford farm, Walworth, Wis. Capacity, 114 tons ; cost, $325.00. UNIVERSAL PORTLAND CEMENT CO. 19 being filled, to tramp down the sides close to the walls, and to keep it leveled off (thus preventing the formation of air pockets), and to mix the heavier portion of the silage with the lighter. Silage has a tendency to cling to the sides of the silo unless well tramped, and the heavier particles roll to the edges while the lighter remain near the discharge. The automatic distributer greatly simplifies the work of filling the silo and does away with much of the tramping. The operator is simply required to guide the mouth of the tube, and the material descends with sufficient force to pack it nicely, making a minimum amount of tramping nec- essary. Economy of Filling the Silo Rapidly: — It is common practice to fill the silo as rapidly as possible, that is, keeping the cutter and blower busy continually. This is the only economical method where the engine and cutter are rented, or hired labor depended upon. How- ever, if these considerations do not enter in, there is no objection to fill- ing the silo gradually, so long as fresh silage is put in before mold is formed on the surface of that previously placed. In rapid filling, a day or two should be allowed for settling, and the silo filled up a second and perhaps a third time in order to utilize all of the space. During the process of filling all doors above the height of the silage should be left open for the purpose of letting out the carbonic acid gas which is given off. Wetting the Silage: — When the filling is finally completed, the top. should be wet down at the rate of about one gallon of water per square foot of surface, and thoroughly tramped. This aids greatly in compacting the silage near the top, reducing the depth of the spoiled material on the surface. In many communities it is a practice to run in a quantity of straw or chaff after finishing with the silage, and then planting oats or other small grain. Where this is done there is seldom any loss of silage worth mentioning, and the growth on top is generally fed to the cattle. Cost of Filling: — Condition of crop, length of haul from the field to the silo, size of silo, method of harvesting- and the cost and arrange- ment of labor are all elements which affect the cost of filling a silo. Farmers' Bulletin No. 292, Department of Agriculture, says: 'Tn many cases a poor arrangement of help is responsible for extra ex- pense. It is not necessary for men and teams to be rushed to their full- Fig. 9. Monolithic silo of Howard and Syl- vester Thompson. Rose Creek, Minn. The first silo in Mower county. Cost, complete, $214 ; capacity, 83 tons. Work done by men without previous experience in concrete work, with local materials. Silo has stood five years, and shows no cracks nor checks. 20 CONCRETE SILOS est extent in order to get the work done cheaply. Some of the most expensive work was conducted with the greatest furore and hurry. The scheme where all are working- and no one is hindered by the others, is the most economical. The following table shows the cost of filling 59 concrete silos dur- ing the season of 1910. Although the location of the various silos is not set down in this table, this in- formation may be found by compar- ing the numbers of the silos with those given in the tables on pages 31 and 32. Almost without excep- tion the figures contained in these tables are considerably higher than usual, due to a poor crop of corn in most sections touched by the inves- tigation and also to the peculiar condition of the crop in some sec- tions of Michigan, where it fell down so badly as to make the use of har- vesters impossible. See Table D, Pages 44 and 45. The average cost of filling 16 concrete silos in Illinois was found to be 57? cents per ton; average of 22 silos in Michigan, 64 cents per ton ; average of 10 silos in Wis- consin, 57 cents per ton; average of 4 Minnesota silos, 72 cents per ton ; of 2 Ohio silos, 89 cents per ton; and of 2 Missouri silos, 50 cents per ton. The average cost of filling silos of 100 tons or less capacity was found to be 70 cents; 100 ton to 200 ton silos 58 cents, and silos over 200 tons 57 cents. The average for all the silos investigated was found to be 62 cents. Recent investigations by the University of Illinois show the aver- age cost of filling silos, including cutting crop in field, to be 58 cents per ton in Illinois, which figure compares favorably with the average of S7 J / 2 cents obtained in the investigation conducted by this com- pany. Farmers' Bulletin No. 292 on the "Cost of Filling Silos," shows a range of 46 cents to 86 cents per ton on the 31 silos inves- tigated, giving an average of 64 cents as against the average of 62 cents obtained in the investigation conducted by this Company. Total Cost of Silage : — The same elements which determine the cost of filling the silo, determine the total cost of the silage, with additional items including cost of the land, cost of tillage and interest on investment. Farmers' Bulletin No. 32 states that "In the writer's experience in the Central West the cost on high-priced land has been Fig. 10. Silo with concrete roof and chute on the farm of Dr. Hammond, Wheaton, 111. Built by the New Enterprise Concrete Machinery Company, Chicago. UNIVERSAL PORTLAND CEMENT CO. 21 about $1.50 per ton. F. S. Peer in a recent book which treats of silos and silage, gives the cost in his experience as $1.20 per ton. Professor Wall of Wisconsin, places it at $1.00 per ton to $1.50 per ton, including cost of seed, preparation of land, in- terest on investment, cultivation of the crop, cutting and filling- the silo. King, when studying this subject in Wisconsin, found that for a number of farms in that State, the cost averaged 7314 cents per ton." Farmers in the vicinity of Or- chard Ohio, have computed the cost of their silage at $1.12 per ton. Mr. James Dorsey, of Gilberts, Illinois, puts the full cost at $1.00 per ton in his section of the country. Some years ago silage cost $1.50 per ton at the Purdue Experiment Station and farmers in various parts of In- diana estimated the cost of their silage at 50 cents to $2.00 per ton. Fig. 11. Monolithic silo of Fred Wieland, New Richmond, Wis. This silo keeps the silage perfectly, but. is unsightly, owing to bulging of the forms, which were also badly off center, and not properly braced. If these figures on the cost of silage are compared with those for hay or other dry feed, silage will be found much cheaper ; to this ad- vantage must be added that of the larger milk flow obtained where silage is fed. Using off the Silage SILAGE is always used off the top of the silo. Any opening in the bottom would admit air, which would cause the silage to spoil. A large number of farmers commence to feed out of the silo as soon as filling is completed, thus avoiding any loss whatever on the top. If this is not done, the shallow covering of spoiled silage must be removed and thrown away when feeding is begun. The silage must be fed off in layers of at least two inches each day in order to prevent the formation of mold. Most authorities advise that the surface of the silage be kept as nearly level as possible so as to present the smallest possible surface to the air. In some parts of the country, however, where the winters are severe, it is common practice to keep the edges lower than the center, making the surface of the silage cone-shaped. This is said to prevent to a large extent the freezing which sometimes occurs around the edges near the top. Never throw down the chute more silage than will be required immediately, being careful to keep the doors between the chute and the barn closed whenever not in actual use. Care in this respect will keep silage odors from reaching the barn. 22 CONCRETE SILOS The Advantage of Concrete as a Silo Material IT HAS been admitted by those who have studied the subject from an impartial standpoint, that silage can be kept in good condition in a silo of any material — be it concrete, stone, tile, or woo d — if the material selected is properly used. The length of time for which the silo will continue to fulfill in a satisfactory manner the service required of it depends, how- ever, upon the selection of the ma- &?»my~ ■ terial best able to combat the action of the elements, withstand the heavy strains due to the silage, and furnish a reserve for such extraor- dinary conditions as fires and cy- clones. Concrete — whether placed in forms or cast in blocks — is the ideal silo material because it is perma- nent, wind-proof, rodent-proof and fire-proof, and is economical in first cost and maintenance. As regards permanency, there is no question but that a good concrete silo will re- main indefinitely. Concrete grows stronger and tougher with age, out- lasting almost every other known material. Reinforced concrete is the strongest and most enduring con- struction known. It is selected for the great engineering projects — long bridges, massive dams, and lofty skyscrapers. While great financial loss seldom follows the collapse of a silo due to wind pressure, the matter is worthy of consideration because of the frequency with which wooden silos blow down. Indeed, in many parts of the country wooden silos can be found which have blown down three or four times. The development, during the past ten years, of slender reinforced concrete chimneys of great height, shows that from a standpoint of safety against wind resistance, this type of construction is unequaled. Mice have been known to cause considerable loss by burrowing into wooden silos. Mice holes allow the air to get in, often causing the silage to spoil for a foot or more in all directions from the holes. Mrs. L. H. Adams, of Parma, Michigan, had an experience of this sort, and as she has a concrete silo of the same size adjoining the stave silo, a fair comparison between the two is easily made. The loss of silage from mice holes in the wooden silo brought the total loss in that silo up to more than twice the loss in the concrete silo, notwith- standing the fact that the latter was not provided with roof, chute, or doors, the continuous door openings being roughly boarded up/ Fig. 12. Monolithic silo of Mr. Charles Worth, Elkhorn, Wis. Built by Mr. Worth in 1908, with the assistance of farm labor, and re-inforced 'with about 4 tons of wagon tire steel. The cost of the silo complete was about $500.00. ' UNIVERSAL PORTLAND CEMENT CO. 23 Concrete silos prevent silage from drying out. The antiquated idea that the juices of the corn seep through concrete walls with bad effect upon the latter has been entirely disproved — in fact, it never has been entertained for a minute by owners of concrete silos. The bugaboo of a concrete silo disinte- grating through the action of corn acids is an absurdity. There are hundreds of cases where the con- crete bases and floors of wooden silos have been in use for a long term of years without discoloring or disintegrating in the least, show- ing conclusively that silage acids have no effect on good concrete. Fireproof Construction The farmer, of all people, is at the mercy of fire. Let a blaze once start in or about his barns and the chances are small for saving any of the surrounding structures. Fire fighting apparatus is out of the question, the water supply is gen- erally limited, and in nine cases out of ten help cannot be summoned until the flames are beyond control. Silo fires usually cause great loss because the feeder of silage is entirely dependent upon his silo all through the feeding season, which covers the greater part of and sometimes the entire year. The loss of the silo fre- quently means that the cattle have to be sold off, always at considerable sacrifice. Concrete silos of either the monolithic or block type are absolutely fireproof — of such a con- struction that they might be used for chimneys. If equipped with a concrete chute the concrete silo will protect the silage perfectly, and in the event of a fire not a pound need be lost. Mr. George Pulling's Silo: — During the winter of 1910 fire de- stroyed the barn of Mr. George Pulling, near Parma, Michigan, ad- jacent to which was Mr. Pulling's new 85-ton monolithic silo, erected at an expense of $300.00. This silo, one of a large number of similar ones put up in that part of the country by Mr. Charles Nobles, of Kalamazoo, came through the fire in good shape, with silage in per- fect condition. At the time of the fire the silo contained about 50 tons of corn silage, and as hay was then selling in the vicinity for $15 per ton, dry feed to take the place of the silage would have cost probably $500, an amount greater than the cost of the silo and silage combined. Fig. 13. 11x28 monolithic silo, built by Gar- rett Wierenga, Hudsonville, Mich. Capac- ity, 51 tons ; cost, complete, $105. This silo was put up in 15 days by Mr. Wierenga, with the assistance of farm hands. Since com- pletion, two years ago, the silo has given excellent satisfaction. 24 CONCRETE SILOS ■ Mr. A. B. Main's Silo: — A striking example of the value of fire- proof silo construction is presented in the accompanying illustrations, showing the 550 ton concrete block silo of Mr. Arthur B. Main, Dela- ware, Ohio, before and after the disastrous fire which destroyed his barn in October. 1910. This silo was built for Mr. Main during the Before the fire After the fire Fig. 14. Concrete Block Silo of Arthur B. Main, Delaware, Ohio. This silo is 20 feet in diameter and 60 feet in height and was built by the Perfect Reinforced Silo and Cistern Block Company, Delaware, Ohio. The adjoining barn with 180 tons of hay burned during the autumn of 1910. The silo shows no other effects of the fire than those which can be seen in the illustration. Its 530 tons of silage were kept in perfect condition with a loss of less than 300 pounds. UNIVERSAL PORTLAND CEMENT CO. 25 summer of 1909 by the Perfect Reinforced Silo c+ <->f all S.S.Lee, Lowell, Mich., built during 1910 by average COS! OI ail R. C. Angevine, Coldwater. Diameter, 14 siloS, Capacity feet; height, 36 feet. Cost, $350, complete rnnre than 200 tons 2 18 except for gravel and scaffold. more tnan £\AJ tons 6.LO Average cost of all silos 2.30 3.11 The cost of a concrete silo depends primarily upon local condi- tions. The price of gravel and cement and the cost of labor are the determining factors. These vary so greatly, however, with time and place that no attempt will be made to give them here. A good con- crete silo of either monolithic or block construction usually costs no more, and in some cases a great deal less, than a good wood, brick or tile silo. The concrete silo has the advantage of a lower cost of up-keep. *Taken from only two silos, undoubtedly be much higher. A fair average for the State would UNIVERSAL PORTLAND CEMENT CO. 31 TABLE E. COST OF MONOLITHIC SILOS. Silo ] No. Diameter in ft. | Height in ft. Capacity in tons Entire Cost Cost per ton of Capacity Location 1 16 37 161 $ 525 $ 3.26 Belvidere, 111 nois 2 16 44 207 695 3.36 Carlton, " 3 15 30 105 400 3.81 Downer's Grove, " 4 16 32 131 500 3.82 Downer's Grove, " 5 20 40 282 550 1.95 Dundee, a 6 20 40 282 720 2.56 Dundee, " 7 12 27 58 241 4.15 Effingham, " 8 18 40 228 620 2.62 Elburn, " 9 18 40 228 620 2.62 Elburn, " 10 20 40 282 680 2.41 Elburn, " 11 20 40 282 680 2.41 Elburn, " 14 16 40 180 550 3.05 Kaneville, " 15 17 42 218 650 2.98 Lake Forest, a 16 17 42 218 650 2.08 Lake Forest, " 17 18 46 277 650 2.35 Marengo, " 18 18 36^ 200 409 2.09 Pingree Grove, " 20 18 34 181 490 2.70 St. Charles, " 21 16 30 119 405 3.40 St. Charles, " 22 20 40 282 680 2.41 St. Charles, " 23 18 38 212 575 2.72 St. Charles, << 24 12 38 94 300 3.19 St. Jacob, tt 25 18 40 228 550 2.41 Wheaton, tt 26 24 50 550 27 24 50 550 1600 '.97 Winslow, " 28 24 50 550 29 20 40 282 500 1.76 Coldwater, Michigan, 30 20 40 282 500 1.76 Coldwater, tt 32 14 45 165 306 1.87 Eau Claire, " 33 14 46 170 400 2.35 Eau Claire, " 34 12J4 36 95 163 1.72 Eau Claire, a 35 14 36 118 200 1.70 Eau Claire, it 36 55 190 3.45 Grandville, a 37 ii 28 51 105 2.06 Hudsonville, a 38 14 28 83 250 3.00 Kalamazoo, tt 39 12 30 67 250 3.72 Kalamazoo, a 42 14 30 91 130 1.43 Lansing, a 43 14 32 100 169 1.69 Lansing, a 44 18 40 228 550 2.41 Marquette, " 45 14 40 138 295 2.14 Parma, tt 46 14 40 138 300 2.18 Parma, a 47 12 36 87 230 2.64 Parma, it 48 12 36 87 240 2.75 Parma, t 49 12 36 87 300 3.45 Parma, a 50 14 47 175 300 1.72 Sodus, a 57 20 45 330 550 1.67 Cedarburg, Wisconsin, 58 20 45 330 550 1.67 Cedarburg, " 61 16 30 120 500 4.16 Elkhorn, tt 64 16 40 180 275 1.53 Hudson, tt 65 14 52 190 600 3.16 Irma, 66 14 36 118 175 1.48 Lake Geneva, tt 68 14 36 118 293 2.48 Madison, tt 71 16 30 120 260 2.16 New Richmond, tt 72 16 30 120 260 2.16 New Richmond, tt 73 16 37 161 199 1.24 New Richmond, tt 74 13 30 79 168 2.13 Roberts, tt 75 16 30 120 114 .95 Roberts, 76 16 30 120 180 1.50 Roberts, tt 32 CONCRETE SILOS TABLE E— Continued. Silo No. Diam- eter in feet Height Capacity feet tons Entire cost Cost per ton of capacity LOCATION 77 78 79 80 81 85 89 90 93 94 95 96 97 102 103 104 105 106 107 108 110 16 30 120 177 1.47 16 38 167 195 1.17 14 35 114 325 2.85 14 28 83 400 4.80 60 40 2250 2500 1.11 14 29 87 115 1.32 20 32 205 380 1.85 14 28 83 214 2.58 16^ 33 144 475 3.30 20 40 282 500 1.77 16 38 167 500 2.99 16 40 180 550 3.05 14 30 91 340 3.74 16 40 180 344 1.91 16 32 131 315 2.40 12 30 67 250 3.72 18 38 211 204 .97 12 24 49 145 2.96 12 24 49 165 3.36 17 38 190 400 2.10 18 40 228 600 2.64 Roberts, Wisconsin Roberts, Walworth, Walworth, Waukesha, Jordan, Minnesota Owattona, Rose Creek, Wheaton, " Centerville, Indiana Fort Wayne, Huntington, Oil City, Roanoke, Missouri Springfield, High Bridge, Kentucky West Paint Lick, " Fort Collins, Colorado Fort Collins, Iowa City, Iowa Warren. Pennsylvania TABLE F. COST OF CONCRETE BLOCK SILOS. Silo No. Diam- eter in feet Height Capacity in in feet tons Entire cost Cost per ton of capacity LOCATION 12 16 38 167 $ 450 $ 2.70 Kaneville, Illinois 13 16 44 207 450 2.18 Kaneville, 31 12 32 74 163 2.20 Coloma, Michigan 40 12 30 67 138 2.06 Lansing, 41 12 38 94 180 1.92 Lansing, 51 8 37 40 227 5.70 Sodus, 52 12 30 67 300 4.48 Sodus, 53 12 30 67 180 2.70 Zeeland, 54 10 20 36 110 4.20 Zeeland, 55 10 28 42 160 3.80 Zeeland, 56 10^ 28 45 170 3.78 Zeeland, 59 16 34 143 340 2.38 East Troy, Wisconsin 60 14 35 114 300 2.64 East Troy, 62 14 30 91 450 4.95 Elkhorn, 63 18 33 174 400 2.30 Elkhorn, 67 12^ 38 100 500 5.00 Lake Geneva, " 69 16 32 131 410 3.13 New Richmond, " 70 16 32 131 410 3.13 New Richmond, " 82 16 42 193 550 2.83 Austin, Minnesota 83 16 30 119 400 3.36 Claremont 84 16 32 131 400 3.05 Claremont, 86 14 32 100 312 3.12 Litchfield, 87 14 32 100 380 3.80 Northfield, 88 14 32 100 375 3.75 Northfield, 92 14 32 100 225 2.25 Stillwater Jet, " 98 20 60 530 750 1.42 Delaware, Ohio 99 14 40 138 420 3.04 Greenfield, 100 12 33 y 2 80 250 3.12 Lorain, 101 12 30 67 200 2.98 Marysville, 109 16 34H 146 475 3.25 Butler, Pennsylvania UNIVERSAL PORTLAND CEMENT CO. 33 Time Required to Build Concrete Silos THE average time required to construct a monolithic silo is from one to two weeks, depending upon the height, number of men on the job, conditions of weather, and the height of wall accommodated by the forms at a single filling. Where the work is done by home labor and there is no contractor or competent foreman in charge, occasionally more than 2 weeks are required to complete the work. The block silo can usually be put up in 4 days to a week, de- pending upon its size and the num- ber of block masons employed. After completion it should be al- lowed to stand at least a week be- fore filling, to allow the mortar to become firm and hard. If the silo is to be filled during the early part of September, work on the foundation should be commenced no later than August 20th. In all cases the silo should be completed several days before being subjected to the strain caused by filling. A Comparison of the Monolithic and Concrete Block Types. Two general methods of con- crete construction are available for silo work — the monolithic and the concrete block. With the- former method, the materials are hauled to the site of the silo and there mixed and placed within forms; the latter method requires that the block be made and cured in some convenient place, and later hauled to the site to be laid up in the wall. Each method has certain advantages and disadvantages, but the matter of personal choice generally influences the decision to build either with monolithic walls or with block. The monolithic silo is generally the easier of the two for inexperienced persons to build, and is usually a little cheaper than the block, as it does not require the service of good masons or the use of a block machine ; the block silo, however, makes the use of forms unnecessary, produces a wall with continuous vertical air spaces, and slightly reduces the amount of materials used. The decision to build either of monolithic or of block construc- tion very often depends upon the availability of materials. In locali- ties where materials for monolithic work are abundant and of good quality, it is hardly practical to haul blocks farther than eight or ten miles; on the other hand, if there is no good sand or gravel nearby, block work may be preferred to the monolithic. In such cases, it may be found economical to haul blocks from a greater distance, or make them on the site, if need be. Fig. 21. Block silo of C. E. Deaner, Sodus. Mich. Although Mr. Deaner has but 17 acres of land, he has a 40-ton silo (diameter, 8 feet; height, 37 feet) . Mr. Carl Tillstrom, Benton Harbor, Mich., was the contractor. This silo was erected complete in 8 days. 34 CONCRETE SILOS Building the Silo CONTRACT WORK: — Where the services of reliable concrete silo contractors can be obtained, it is generally advantageous to have the silo built under contract. The cost of silos built in this manner is generally no more than otherwise when quality of the work, convenience and time are considered. The advantages ^f good system, competent overseeing and general experience in the work justi- fies a greater cash outlay than is needed for home-made silos, al- though in a great many cases the actual expense of a silo built undei contract is no greater than if built by the owner. If it is desired to put up the silo during a time of yeai when work is over plentiful or fart labor scarce, building the silo under contract will solve the labor prob- lem. Of 110 concrete silos recently inspected, 74 were built by con- tractors, 9 by the owners under ex- perienced foremen, and 27 by the owners without anv assistance whatever. In over one-half of the cases where the silo was built under contract the owner furnished a part of the labor, and in about one-fifth of the cases the owners furnished the cement. Almost without ex- ception, the owners of contract-built silos furnished the sand and gravel, for which they received credit on their accounts, at a stipulated rate. Hk. II. One ox me numerous concrete silos around Coldwater, Mich. E. W. Treat, owner. Diameter, 14 feet; height, 40 feet; capacity, 140 tons. Work Under Hired Foremen: — In a large number of instances farmers have built their own silos under the supervision of a com- petent foreman hired by the day. Foremen who make a business of superintending silo work frequently have their own forms which they rent to the farmer for a nominal sum. When the silo is built under contract, the farmer usually does the hauling, and sometimes fur- nishes the materials and a part of the labor; when a foreman is employed, the farmer must buy and haul the materials, furnish the labor, and pay for the work as it progresses, without an accurate previous knowledge of the cost. In addition he sometimes has to build his own forms. UNIVERSAL PORTLAND CEMENT CO. 35 Work Under Home Supervision: — If neither a good contractor nor a good foreman is available, the farmer may undertake the build- ing of the silo, but he must pay close attention to the details of the work. The inexperienced worker with concrete too often considers cement a sort of magic material which may be used without precau- tion and still secure first class work. On the contrary, precautionary measures are constantly necessary and the directions given on the following pages must be carefully complied with if the best results are to be obtained. To acquaint inexpe- rienced contractors as well as those desiring to build their own silos with the best practice, is the purpose of the two sections immediately fol- lowing. A later section is devoted to a description of several of the leading commercial silo forms now upon the market. Co-Operation in Silo Work: — Where there are several silos to be built in the immediate vicinity, and it is desired to use home-made forms and do the work with home labor, a very considerable saving can be made by co-operation. With moderately fair weather, such as usually prevails from April to Octo- ber, four or five farmers working to- gether can construct moderate size silos in an average time of less than two weeks, working but 4 hours per day, with one set of forms. In about two months' time they can complete a good silo on the place of each, without having - this work interfere seriously with general farm duties, and at a comparatively small expense, as only one set of forms is used. In "The Farmer" for April 29, 1911, Mr. Charles Nelson, of Meeker County, Minnesota, concluded a letter on "Co-operation in Silo Building" with the following paragraph : "Farmers, get to- gether, buy in carload lots material for silos of whatever material desired. Co-operate in building, filling, and in the purchase of machinery. It means a saving of dollars and cents which may be needed for the home or for other improvements." Fig. 23. Monolithic concrete silo on farm of F. J. Murphy, near Wheaton, Minn., built under the direction of Martin Peterson, con- tractor. Height, 33 feet ; capacity , 144 tons. 36 CONCRETE SILOS Foundations Laying Out the Work : — The site of the silo having been selected and its size determined, the excavation should be laid out. This may be done conveniently with a sweep similar to the one shown in Figure 24. A heavy stake is driven in the center of the spot selected for the silo and allowed to project above the surface about one foot. The arm of the sweep may be made of a two-by-four at least two feet longer than one-half the inside diameter of the silo. The arm swings about the stake as a center, being held to the latter by large spike. A chisel-shaped board or template is placed as shown on the arm of the sweep, so that when the latter is swung around the stake, the chisel-shaped board will describe a circle with a diameter 2^2 feet greater than the inside diameter of the completed silo. This will erive the outer line of the excavation and also foundation. , Figure 24. Simple sweep, convenient in laying out excavation Excavating: — The excavation should be carried to a depth not to exceed 6 feet below the floor of the barn where the silage is to be fed. The objection to going deeper is that it adds to the labor in remov- ing the silage. In all cases, however, the. foundation should be estab- lished below frost. All of the earth within the line described by the sweep should be removed down to a point one foot from the bottom, and below this the excavation should be made the shape and size of the foundation, 2 feet wide by 1 foot in depth, so placed that the outer edge will come directly up to the edge of the excavation, assuming that the sides of the latter are perpendicular. If the silo is to be equipped with a concrete chute, the founda- tion for the chute should be put in at the same time as that for the silo. As the chute is rectangular in shape, no difficulty should be encountered in excavating for the foundation, which will be at the same depth as the silo foundation, and two feet in width by one foot in depth. Placing the Concrete : — The concrete for the foundations should be made in the proportion of 1 sack Portland cement to 3 cubic feet of coarse sand, to 5 cubic feet of screened gravel or crushed stone. The sand should be free from clay or organic matter, and the gravel or stone should contain no particle smaller in size than %. inch. The ma- terials must be thoroughly mixed and enough water added to give a quaky consistency. The concrete may usually be placed in the exca- UNIVERSAL PORTLAND CEMENT CO. 37 vation without any forms whatever, but in some kinds of soil light boards, held in position by stakes, may be necessary. The top of the foundation must be levelled off with a straight edged board and spirit level. After 24 hours, the foundations have generally hardened sufficiently so that the walls may be built upon them. Where soft ground or quicksand is encountered, the foundation may be made 3 or 4 feet in width, to provide plenty of footing. l*-2-0'-*| Footings \-3-5 Codcrete j Figure 25. Concrete Silo Footing and floor, suitable for either Monolithic or Block Silos Imbedding Reinforcing Rods: — If a monolithic silo is to be built, the vertical reinforcing for the walls, consisting of J^-inch round rods spaced 3 feet apart, should be imbedded in the foundation a distance of 8 or 9 inches. If a block silo is to be built no vertical reinforcing need be placed. TABLE G MATERIALS FOR SILO FOOTINGS AND FLOORS. u£ o •a u" .£•« *¥» ok" 1 N a ■ rt UU Footings Quantities 8 1.5 10 1.8 12 2.2 14 2.5 16 2.9 18 3.2 20 3.6 22 3.9 Cement Sand I Gravel Bbls. v ds. 1 yds 1.8 2.2 2.7 3.1 3.6 4.0 4.4 4.8 0.7 0.8 1.0 1.2 1.3 1.5 1.6 1.8 1.4 1.6 2.0 2.4 2.6 3.0 3.2 3.6 (D'O i -O 3 Floor Quantities Cement Bbls. [ 0.5 0.8 1.0 1.6 2.2 2.8 3.5 4.3 .62 1.00 1.25 2.00 2.75 3.50 4.35 5.33 Sand yds. Gravel yds. Footings and Floor Total Quantities Cement Bbls .25 .37 .46 .75 1.00 1.30 1.60 2.00 .46 .75 .92 1.50 2.03 2.58 3.22 4.00 2.42 3.19 3.94 5.08 6.33 7.47 8.74 10.13 Sand yds. 0.93 1.17 1.46 1.94 2.31 2.79 3.21 3.78 Gravel yds. 1.86 2.34 2.92 3.77 4.62 5.58 6.42 7.56 38 CONCRETE SILOS The Floor : — After the foundation is completed, the earth within Should be dug out for a depth of about 8 inches, and a concrete floor built as shown in Figure 25. The floor should be given a slight pitch in all directions toward the center, and, if necessary, an outlet to a line of drain tile should be put in. Outlets are not usually provided in silo floors, but in a few instances silos have failed because of the pressure of a large quantity of water accumulated under unusual conditions, with no provision for escape. In such cases the stress on the walls may reach two or three times that usually imposed by the silage. Although the majority of silos are not provided with a drain, it is undoubtedly a desirable feature. The top of the drain should be protected from accumulations on the silo floor, by a small wire mat. A 4-inch or 6-inch drain tile will be sufficient. The floor should be made of 1 :2^4 :5 concrete. A smooth finish is not consid- ered necessary. Figure 26. Model of the Farmers Institute Silo Forms, which has been the means of showing scores of Northern Wisconsin farmers how to build con- crete silos. Forms built after this model cost $60_to $75. Mr. David Imrie, of Roberts, Wisconsin, is owner of this model. UNIVERSAL' PORTLAND CEMENT CO. 39 Monolithic Concrete Silos THE word "Monolithic" coming from "mono" meaning one, and "lith" meaning stone, is used in concrete work to denote the objects of concrete which are one continuous solid mass or "as one stone." Contrasting with the monolithic are several systems of concrete construction such as the concrete block, concrete brick, con- crete tile, unit column and slab, and cement plaster. The systems of concrete construction most com- monly used are the monolithic and the concrete block. The object of the present section is to supply the necessary information for construct- ing monolithic silos, in cases where the work is all done by the owner who is dependent entirely upon his own resources, or by contractors not familiar with this class of work. Home-Made Forms. The form described and shown on the following pages is a combina- tion of the Wisconsin form, de- signed by the Agricultural Depart- ment of the University at Madison, under Professor C. A. Ocock, and the Farmers' Institute form, de- signed by Messrs. John and David Imrie of Roberts, Wisconsin. Both of these forms have been used with great success among the farmers of Wisconsin and adjoining states and appear to be in many respects the most practical forms yet devised. Figure 26 shows a photograph of a model of the Farmers' Institute Form. The model was obtained through the courtesy of Mr. David Imrie, who has introduced this form to hundreds of farmers in conjunction with the work of the Wisconsin Farmers' Institute. Description of Forms: — The inner form consists simply of 16 segments or ribs made of 2"xl2" plank, 16 cleats made of 2"x6" plank, a number of l"x6" matched floor boards, a quantity of No. 28 gauge galvanized sheet steel, and 64 ^-inch bolts A]/ 2 inches long. (See Figures 28 and 29.) In making the form it will be convenient to refer to the table of materials given on page 43, for the dimensions of the ribs. Ihe procedure should be about as follows : Draw a circle on the barn floor, of a diameter two inches less than the inside diameter of the silo. For this purpose use a sweep Fig. 27. The first monolithic silo in Northern Wisconsin, built by G. W. Graham, of Rob- erts, with the Farmers Institute Silo Farms, a photo of which is shown on page 38. Mr. Graham's silo cost $114, and has a capacity of 120 tons. 40 CONCRETE SILOS with a soft pencil or crayon attached to one end. Do not use a cord and chalk as the former will stretch enough to distort the circle, and the latter will make too wide a line. Space off the circumference into eight equal distances. (These may be obtained by taking distance "C" from the table of materials.) For the ribs lay down the 2"xl2" planks on the circle drawn, marking the arc on each plank with the sweep. The length of the rib should also be marked off on the plank in a radial direction, using the sweep as a guide. All of the dimen- sions for the ribs may be obtained from the table of materials, if desired. A hole 4"x4y 2 " is cut in the center of each rib, as shown in the sketch accompanying the table of materials, page 43. m _■ n No. 18 gausre No 28 gauge Diam. i IB '" s ^ -a be •" u c u galvanized sheet iron 3 / galvanized of sheet iron 3 / Silo A L L' R ° — c ^« .5 wide Feet Needed wide Feet Needed 8 ft. 9 " 2' 5%" 3' m" 3' 11" 51 30' 3" 25' 0" 10 " 8 " 3' 3 " 3' 10^" 4' 11" 63 36' 7" 31' 6" 12 " m" 4' VA" 4' 77/ 8 " 5' 11" 76 42' 10" 37' 8" 14 " 6 " 4' ioy 2 " 5' 5H" & 11" 88 49' 3" 44' 0" 16 " 5 " 5' 9 " & 2y 2 " 7 11" 101 55' 6" 50' 0" 18 " W 6' 6y 2 " 7 0%" 8' 11" 113 61' 9" 56' 6" 20 " 3 * 7 434" 7 934" 9' 11" 126 68' 0" 62' 10" 22 " 2H" 8' 3 " 8' 7y 4 " 10' 11" 138 74' 5" 69' 2" Cost of Forms: — Forms of this type can be made for twenty-five to fifty dollars, and in one instance a farmer built an equipment similar to that described here at a cash outlay of only $15.00. Forms can generally be disposed of after use at a price equal to the total cash outlay to the builder, so that the use of these in building his silo only costs him his labor. A single set of forms is often used on sev- eral silos, each user selling his forms to the next man for a sum slightly less than what he paid for them. Care in Bracing Supports: — As the inner form is moved upwards it will be necessary to securely brace the upright supports. This is very es- sential. No weak or rotten lumber should be used, and all bracing: should be put where it will carry the load in the best and most secure manner. The double two-by-four supports recommended have ample strength to carry the weight if properly braced, but this precaution must not be neglected. The uprights should be braced at intervals of five feet (every two courses) with horizontal boards running from one upright to the next, and braced back against the wall as shown in Figure 31. Boards 1x6" or 2x4" will be large enough for this purpose. About every 15 44 CONCRETE SILOS ■R n> 5 °CUcL M C C o> O g So OS n no O S*3 0> C 01 DCS 11 3 C3 '-, t! ^ >>'7 Son gad "ON OIIS o in in o t> c^ «o 00 od CD CO CO CD CO CO CO -f lO cc O O O CO o o o o o o o © o o o us © t-^ la «d i-i CO CM CM o o o o o o o o o © © © © © © © © © © © © © © © © © © © © © T-* T-i CD © © io © us © cm © M 1* ^f W © GO © "<** © © O © © © © © © © © o © o o o O0 t> Oi ■* O in © © © © CM © © © © IT3 © © ^ © i— I CM CM CM CM (M CM i- 1 "<*< CO m **t* © N CO CO N © © CO io © © © © © © IM N CO CO N © © t- "^ *« CM CI © © © rH i-t ,H iH 4-inch hooked bolts, which are fastened to the vertical reinforcing rods, adjacent to the doorway. 34 and the frame assembled by means of the bolts. Frames and Doors: — Before commencing work on the silo walls, the channel for the door frame should be drilled as shown in Figure It will probably be found convenient to order the channels and rods from the local blacksmith, who has facilities for drilling the holes in the channels and threading the rods as required. The door frame may then be brought on the job ready to be assembled. The doors should also be made before the wall is commenced. These con- sist simply of 2xl2-inch plank planed on both sides, 34 inches long-, with f-inch holes drilled through the center to accommodate the bolt and hook by which the door is held to the J- inch bolt in the frame. The bolt in the cen- ter of each door has a screw eye on the outer side on which hangs a common gate hook. (See Figure 33) . The doors are given a slight taper all around towards the outside. Erecting and Anchoring Door Frames : — As soon as the silo wall has been brought up to within 1 foot of the level of the barn floor, the door frame is raised to the position it is to occupy in the silo and held securely in place by means of wooden bracing and guy ropes. The wall is then continued up to the level of the barn floor. In the case of tall silos, where the steel frames have to be made in two or more sec- tions, it will be found convenient to put in only one section at a time. The sections may be joined together with splice plates. Five or six of the wooden doors should be painted with crude oil and then put on and the con- creting resumed. These doors are placed in position for the purpose of keeping the concrete from running around the steel frames on the inner side of the wall, which would otherwise be possible since the distance between the inner and outer forms is 6 inches and the width of the frame but 4 inches. After the work has proceeded upwards a short distance some of the lowest doors may be removed, taking care not to knock off corners of 4<-^ rt ^J CHAMNCL I i Ll i i I £ r ?ARn Floor Figure 34. Spacing of holes in Steel Channel Side Frame for continuous door openings. 48 CONCRETE SILOS green concrete. These doors may then be replaced on the frame at a point above the forms. Non-continuous doors: — Non- continuous doors are perhaps easier to build than continuous doorways, and if the owners are satisfied that they provide suffi- cient room for getting the silage out conveniently, there is no objection to their use, although on the other hand, they possess no great advantage over doors of the continuous type. The arguments often heard that the non- continuous door silo is a stronger type than the other, and vice versa, carry little weight, as either type may be made sufficiently strong. Fig. 35. Wooden form for a non-continuous doorway and steel frame made of angle iron. Non-continuous doors are often put in with a distance of about 2^4 feet between them, but the spacing may vary to suit the indi- vidual owner. In all cases the arches between the doors must contain an amount of reinforcing equivalent to the full amount of horizontal reinforcing put around the silo. Thus, if the doors are 3 feet in height, with a distance of 2y 2 feet between them, the horizontal reinforcing in the space between the doors should be equivalent in amount to that placed in Sy 2 feet of the wall where there are no doors. Doorway Form and Frame: Figure 35 shows a form for a non- continuous door opening. The bottom and top pieces are. made of; 2x6" plank cut to the arc of a circle with diameter, the same as the outer diameter of the silo wall. The two sides are made of two-by- fours. A frame of lighter material is placed around the outside of the form for the purpose of making a recess two inches deep around the opening on the inner side of the wall, into which the door will fit. This frame is tapered to permit removal from the wall as soon as the concrete has hardened. It may then be used again for the next door- way above. If desired, a door frame of small angle iron (as shown) may be used to protect the corners of the concrete. The frame should be slipped on over the form, and both frame and form then placed in position. The angle iron should be cut a few inches longer than the dimensions of the opening and the ends embedded in the con- crete. The frame should also be anchored to the concrete by large spikes. Holes to receive the. spikes should be drilled in the angles, 12 inches apart. The spikes should be bent at. right angles to secure a better hold in the wall. UNIVERSAL PORTLAND CEMENT CO. 49 Figure 36. Non-continuous Door, made of double layers of flooring with building paper between. Doors : — The doors may best be made of two thicknesses of 1x6" matched flooring- with a layer of tar paper between. The 1x6" boards are held together by two 1x4" cleats across the top and bottom, and one 2x4" cleat across the center. The middle cleat is made larger than the others in order to take care of the strain caused by the large bolt in the center. A two-by-four, 40 inches long, or a similar piece of material, is placed on the bolt, making a large "button" by which the door is held to the wall. The door is clearly shown in Figure 36. After the silo had Fig. 37. Monolithic silo of Milo A. Jennings, Eau Claire, Mich. been in use a short time the owner enlarged it by putting on a wooden top. Mr. Jennings has since abandoned his dairy business, and will convert the top of his silo into a water supply tank. Dimensions, 14 feet by 46 feet; cost, $40U. bank, Eau Claire, Mich., was the contractor. H. G. Bur- 50 CONCRETE SILOS Constructing Monolithic Silo Walls AS soon as the foundation has hardened sufficiently to allow the work to proceed, the wall forms may be placed in position. Much care should be taken to locate them centrally and in such a manner that the sides are perpendicular. The 4x4-inch up- rights should be carefully put in position at this time, being sup- ported on wooden blocks or flat stones. After the inner form is in position, but before the outer form is placed, the horizontal reinforcing rods for the first three feet of wall should be wired to the vertical rods which were placed in foundation as previously mentioned. The outer forms should then be placed in po- sition and tightened, with the small wooden spacers in place. Before placing the concrete, it will be nec- essary to clean off the surface of the foundation and moisten it thorough- ly. The wall forms, having been previously painted with crude oil or whitewash to prevent sticking, may then be filled with slushy concrete made in the proportion of one sack of Portland Cement to two and one- half cubic feet of coarse sand, to four cubic feet of screened gravel or crushed stone, all of the latter be- ing between % inch and \y 2 inch in size. Fig. 38. R. N. Quimby's silo, Batavia, Mich. Built by R. C. Angevine, Coldwater. Ca- pacity, 90 tons; height, 36 feet. During the Summer 24 hours is usually enough for concrete to harden before raising the forms, but in cool weather a longer time will be required. If the work be undertaken while there is danger of freezing, the usual cold weather precautions must be observed. In such cases the materials should be heated, or at least free from frost, and mixed with hot water. The work in the forms must be protected for several days with manure, straw or a canvas jacket under which live steam is run. Tables of Materials: — Table I shows the approximate number of cubic yards of concrete required for the walls of monolithic silos of various sizes, with continuous doors, and walls 6 inches thick. Table J shows the quantities of cement, sand and gravel or stone required for silo walls, using proportions of 1 sack of cement to 2y 2 cubic feet of sand and 4 cubic feet of screened gravel or stone. It can hardly be expected that these tables will be exact in all cases, as UNIVERSAL PORTLAND CEMENT CO. 51 TABLE I CUBIC YARDS OF CONCRETE.— Walls 6 Inches Thick. Required for walls of Monolithic Silos with continuous doors. Height of silo INSIDE DIAMETER OF SILO. in feet 8 ft. 10 ft. 12 ft. 14 ft. 16 ft. 18 ft. 20 ft. 22 ft 20 9.0 11.4 13.7 16.2 18.3 22 9.9 12.6 15.0 17.8 20.0 22.8 24 10.8 13.8 16.4 19.4 22.0 25.0 27.7 26 11.7 15.0 17.8 21.0 23.7 27.0 30.0 28 12.6 16.0 19.0 22.6 25.5 29.0 32.1 316 30 13.5 17.2 20.6 24.1 27.5 31.0 34.5 38.3 32 14.4 18.3 21.9 25.8 29.0 33.1 36.8 40.8 34 15.3 19.5 23.2 27.5 31.0 35.1 39.0 43.1 36 16.2 20.6 24.5 29.0 32.9 37.2 41.2 46.0 38 17.1 21.8 26.0 30.8 34.8 39.4 43.6 48.4 40 18.0 22.8 27.2 32.0 36.4 41.2 46.0 51.2 42 24.0 28.7 34.0 38.4 43.4 48.3 53.5 44 30.0 35.6 40.0 46.8 51.0 56.5 46 37.1 42.0 47.8 53.0 585 48 43.9 50.0 55.0 61.5 50 51.5 57.5 64.0 the difference in sand and gravel used, as well as other considera- tions, affect the quantities of materials to a considerable extent. These tables are accurate to within 10 per cent. Moving up Forms for the Next Course: — To release the inner form, drive out the keys and if need be, remove a few of the bolts. Slide up the inner form on the upright supports and secure in the new position by the bolts passed through the supports just below the form, as previously explained. The inner form will then be bolted to- gether again and the keys driven into place. After attaching hori- zontal reinforcing rods to the ver- tical rods for the second course, the bolts in the outer form are loosened and the form raised by means of ropes attached to wire handles and running over the little brackets on the uprights. When the outer form is raised to a position flush with the inner form, the lower bolt should be tightened until the form presses snugly against the wall ; spacers should then be placed between the forms and the remaining two bolts tightened until the proper spacing is secured. The forms are then ready for the next filling. Fig. 39. Twin monolithic silos, built by J. H. McCoy, of Harrisburg, Pa., on the farm of Professor F. R. Lilly, near Wheeling, HI. Both silos are 18 feet in diameter, and have a height of about 42 feet and a combined ca- pacity of 500 tons. The walls are 7 inches thick. 52 CONCRETE SILOS 2 "" W OH O p 2 o fc 3 cti H -HJ ff w O ■d u Q c o £ CD cd 01 ►n 2 a < Q o tr >> pq 55 < IB r£ Cq an H w £ . co h ■H H3 o CO CO C3 o If IB ■* rH CO ■* l»- oo CI to CO 00 oo o '0 09 rt rH H ^H rH rH CI CM CI CJ cq CJ CJ CO o c „ Csl rj< in t- 00 o © CI oo to Tf< 00 00 -FH rH CI CO -t> 00 © © rH Cl 00 -T fl r-l H 7-1 ^ H rt i-H i-H cq CJ Cl CJ CJ r« > -r rt< rf -r oo cq a rH o o oo CT2 bC ,_j CO c cq CO -i- in r- oo 00 oo 3 rH rH i-i rH 1-1 i-i rH rH H O 4 cq — CO -r i-H CO CO CO r^ ■CO 00 l- oo oo 05 O l-l s cq i-H CO rH -V *CH rH to c- o "* CO rH oo CO' CO rH CO en 00 OS © CM CO *# CO 1- CO.' oo rH CJ o rH H cq cq CJ cq cq Cl cq cq CO CO rn CO rr to t- OJ o cq CO CO o © © CO +■» CQ -h to CO' 00 © rH CI CO rH CO r~ CO oo •a C rH rt H 1-1 1-1 H cq Cl cq CJ cq CJ CI cq m CO t- l- © © © cq H oo rH US oo p H tH CI CO ^< in CO t- CO © r^ CJ oo rH to CO IB H H rt 1-i H rH rt H cq CI cq cq CJ Cl 01 IB ft 03 s M cq cq rt O o CO 00' oo O0' CO to rH rH CO 09 o rH CO ■^i tK to CO f- 00 oo © CJ •a a cd ^H r-l rt rH H T ~ l 7-1 rt 7-1 rt H CJ CJ CJ cH •* o Oi L~ CO CO rH c 00 Tf CO © 03 IB rH do S3 o CI -» n< in CO 1— CO, CO rH rH rH r-i o s H H H "1 rH H rH r^ h O 00 m © t- cq t- -f o to ^ CO CO be i-l in co r- I-— 00 00 Cl o © rH Cl rH o co r-\ co o to OS -f CO' CO CO cq rt< in in to CO CO t- ^ 00 CO oo c- to © o CJ to' 00 CO lo- CO t- o W CTV CO t- o -f t^ ^H rH co rH to OH o - o 00 CO (TO CJ to r— © to CO © rH CO CQ CO m ^1 If HI to to CO o 1 CM c+ CO CO CO CO ■* -5)< -cw rr to to ■to to CO A 'C 0) s IB IB Tj< CI rH rH CO CTi to rH CO © CO OO CO O 00 CJ to rH CO oo 00 rH CJ a CJ CM CO CO CO CO -^ ■* rH rH rH to ( ) G cq rH O Q L>J 00 CO 00 tr CO CI cq CO o 00 'be H C4 CJ cq CJ cq CO CO oo 00 oo rH rH o C~ IM o CO o to i-H co CO o c^ to oo H rt ri CI cq Cl CJ eq CJ CO oo oo CO OO rH CO CO en rH -CB CO oo ^H CO CO 10. CO 00 o CI 0-3 to H 1-1 H ' H rH rH CJ cq CJ CJ cq +j ° o N tp do CO © CJ U< CO 00 © ICJ rH CO CO © W°35 CI CM cq CJ CO oo CO CO 00 rH rH rH rH rH to UNIVERSAL PORTLAND CEMENT CO. 53 m O o I— I H i— i o z o 00 Q o w o h-t W Q U 2 - S w H K < H O N i— i K O X o o M o < Oh CO cr 00 ^< lo Tt -f CO CD CO SO «*» LO £ Os 00 t^ SO LO LO ~t ■■*■ co rH|N SO to C5 Os 00 K t^ so 1-1 rt ""? 1-1 SO Tt CM o o "" H •"" 1-1 ^h rH mfai e LO ■^ - h On t>» Hn LO Tt co CO CO hW lo • vo CM o Os r^ SO IT) in LT Tt Tt gj 1-1 1-1 '-' v -r co ,_, ~ Os X t^ r^ o rv. LO -T (N ,-< ^< £ >o|ao i-^ *"* Cs o oo SO m LO Tt CO co CO O r+* *-' J H|N 05|00 CO o 00 t^ SO SO lO LI CO 00 CSC Tt CM *-< o O 00 N ' H ^ H *~ ' T ~ t ^ H idao r^ lO ■* CO CM O rH " '" ' *"' Tt —( On 1^ so LO -1- Tt CO CO co LO CM ^H OS 00 t^ SO O LO 04 \o «(Q0 *■* ,H 1-1 m Tt CM ,_, O Os S H(N ^~ T ~ l rH 1-1 io|oo f^N LO ■* a 3 LO O r~ri SO LO LO "* Tt CO CO co £ H T-H ,-H r^ •6 w CD CM O Os X r^ r^ sc nlao < 00 LO t CM CM O Q f*j 1-1 " "^ 1-1 < ^h ex 3 t^ CM Os s. so LO LO 't -3- CO H '-It-' a sn CO CM o o> X tv. mlac ~ 00 SO -I- CO ■"■* 1-1 " a 3 00 lo ,_, OS th inches in width. Wall ties, made of gas pipe slotted at both ends, are placed between the walls in each course at intervals of 3 feet, the slotted ends being bent so as to form a crow foot. Although a large number of double wall silos have been con- structed in various parts of this country by this system, this com- pany considers double walls a precaution rather than an absolute necessity in localities where the climate is not severe. Both single and double wall systems of the New Enterprise Company are pro- tected by patents. Angevine System: — Mr. R. C. Angevine has built a large num- ber of "all concrete" silos in the State of Michigan, using for his purposes a system of wooden forms made of 1x6" wood facing at- tached to the ribs of heavy planking sawed on the arc of a circle. Each form is slightly more than 2]/ 2 feet in height and two forms Fig. 45. Hollow wall concrete silo with con- crete roof, built for Edward Hoyt, Elborn, 111., by the New Enterprise Machinery Co., of Chicago. 60 CONCRETE SILOS are used at the same time, one above the other. This makes it pos- sible for the work to proceed at the rate of 5 feet per day during good weather. The materials are hoisted on a small elevator with power furnished by a gasoline engine. >-.' Angevine silos have a foundation footing 30 inches in width generally placed about 4 inches below the surface. The wall is put in 12 inches thick from the foot to grade, above which point the thickness is 6 inches. These silos are reinforced with heavy steel rods or cables spaced 1 foot apart uniformly. The size of the rods varies with the diameter of the silo and the distance from the top. Before the walls have had time to dry out they are finished off, both inside and out, with a coat of cement and water applied with a brush. The door openings are non-continuous, 24 inches wide by 32 inches high, and are spaced 2 feet apart. The doors are of galvanized sheet steel. The Angevine silos have reinforced concrete roofs, these being made 4 inches thick with a one-fourth pitch. The appearance is greatly improved by a wide cornice running around the base of the roof. Concrete chutes are recommended by Mr. Angevine and are put up wherever the owners desire them. Figure 46. C. A. Anderson's Silo Forms in use near St. Charles, Illinois. The platform on top of the inner Form is a great convenience. Materials are hoisted with the Elevator shown to the right. C. A. Anderson Forms: — Mr. C. A. Anderson of St. Charles, 111., has constructed about fifty silos in. Kane and surrounding counties with the patented system of forms shown in Figure 46. The forms are made of heavy sheet iron braced with 2x4" wood studding and strengthened by strap iron hooks. The forms are raised by jack UNIVERSAL PORTLAND CEMENT CO. 61 screws. The materials are hoisted with the device shown to the right of the illustration. Mr. Anderson has made a number of im- provements on his forms this season, but pictures could not be se- cured in time for publication. McCoy Forms: — For a number of years Mr. John II. McCoy has been successfully using- a system of forms of his own invention in the construction of large silos and railroad water tanks in many parts of the country. This system, which is now owned and used by the Steel Concrete Construction Company of Harrisville, Pa., is Fig. 47. McCoy's system of silo construction used by the Steel-Concrete Construc- tion Company, Harrisville, Pa. shown in Figure 47. The forms are of steel made in sections, each of which is supplied with a separate rig for hoisting. The materials are raised in steel buckets by horse power and deposited on a trough which travels around a circular track. This track makes it possible to move the trough to any part of the work that it is desired to fill. Fig. 48. View taken on a Wisconsin farm where silage is the chief ration. Silo and barn of H. M. Hatch Lake Geneva. Ca- pacity of silo, 110 tons ; cost, $175.00. 62 CONCRETE SILOS Concrete Block Silos HOLLOW concrete block silos are popular in all of the northern states and more especially so in sections where the winters are extremely cold. In North Dakota and Minnesota there are scores of block silos in service, these being preferred to silos of any other construction, because of the security against freezing provided by the hollow wall. The cost of concrete block silos is often a trifle more than for those of monolithic construction, although this is not true in a great many cases. The best concrete block silos are those erected by contractors who have made a specialty of this class of work. Good block silos can be put up with home-made blocks and by home labor, but where there is a reliable block contractor in the vi- cinity it generally pays, in a saving of time as well as in numerous other ways, to have the work done by persons with previous expe- rience. Examining Blocks: — When the work is done by a contractor, the owner should take the precau- tion of examining the blocks which go into his silo, rejecting those that are damaged or of an inferior quality. A crack of any size or broken or crumbly edges indicate a weakness in the block and make it unsuited for use. Blocks may be tested for their water resisting qualities by placing a small amount of water on the surface and observing whether this remains or is absorbed. A block which read- ily absorbs moisture is obviously unsuited for silo work, which dampness must not penetrate. Warped and distorted blocks should be discarded because of their unsightly appearance. Laying the Blocks: — The foundation already described will give as good satisfaction for the block silo as for the monolithic (see pages 36 and 37 and Figure 25). The top of the footing must be made perfectly level, being tested frequently with a level board. As soon as the footing has sufficiently hardened, the top should then be cleaned off and moistened and a coat of slushy mortar % i nc h thick put on. The first band of reinforcing should then be put in, and the first row of block laid on this mortar, beginning the blocks at the two ends of the wall next to the doorway and continuing around. The blocks may be more conveniently set in a true circle if a sweep similar to the one used in laying out the foundation is used here. Should the blocks fail to meet exactly, the circle should Fig. 49. A concrete block silo of pleasing appearance on the farm of Mr. Fred Ludt- ke, near East Troy, Wis. The concrete block chute is a great advantage, and was put on at a slight additional expense. The cost of the silo complete was $300. The owner does not consider a roof necessary. UNIVERSAL PORTLAND CEMENT CO. 63 be enlarged or made a little smaller, whichever happens to be the more convenient. A guide board with a convex curved edge, cut on a circle of the same diameter as the inside of the silo, should then be made and used in place of, or in conjunction with, the sweep in laying up the remaining courses. The Mortar: — The mortar should consist of one sack of Port- land cement to 2 cubic feet of coarse sand, with the possible addi- tion of a small quantity of lime (not over 10 per cent) if need be to make it easier to work. Before laying up the block see that they are thor- oughly sprinkled, which will pre- vent them from drawing moisture from the mortar. No more mortar should be mixed at one time than can be used up within 30 minutes after first moistening. If lime is used it must be thoroughly slaked. Reinforcing: — The only failures reported on block silos have been due to a lack of sufficient reinforc- ing, caused in most cases by the overconfidence of the builder in the strength of the blocks, or fail- ure to realize the enormous outward pressure of the silage. Horizontal reinforcing is of the most impor- tance and must not be overlooked. Vertical reinforcing in block silos is not considered necessary. Table M shows the size of rod which should be placed between each row of block or in the groove in each row of block, if such a groove is provided. Reinforcing rods in block silos are not lapped in the ordinary fashion, but are anchored around a block as shown in Figure 51, or the ends are hooked to- gether. Example: — For illustration, let it be assumed that the proper method of reinforcing a silo 32 feet in height and 16 feet in diameter is desired, blocks 8 inches in height being used. Referring to the above table, we run down the vertical column at the left until the figures indicating the greatest depth of the silo are reached. In this case these figures are "28-32 ft." Running directly across horizon- tally to the 16-foot diameter column, we find that the proper rein- forcing 28-32 feet from the top of the silo is one f^-inch rod between each course of block; following up directly the 16-foot diameter column, we find that ^-inch rods must be used between each course until a point 16 feet from the top is reached. From here up ^-inch rods are used until 8 feet from the top when No. 6 rods are sub- stituted. Fig. 50. Block silos on the farm of Henry- Brown, near Elkhorn, Wis. Capacity, 92 tons. Cost, $425, complete. Built by Rein- ert, Malsch & Baumback, Lake Geneva, Wis. 64 CONCRETE SILOS Q bfl bd W J3 x « H-l «) tn £ X! u o *u Xi u _c C ft O o 1—1 « ^ X w o o PQ cq s £ 2 o £ s 0) VO LO ■* CO CM o ON X rv, no in "o cm X * O VO CM X CO ON in ^h rv. X! 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O ~ o O © o O O C o o ^ O o cm X ^r 3 O CM X ^ o O VO rv. rv X ■3\ ON O p CM X £ u ni »> _ ^ -*j O c* Tj oj — H^ CJ »p« s° M- c p O CM •<* VO X o CM ■* vO oo w CM ■P o ■* o o o o o o o O o c c c Q 2 Z Z Z Z Z Z z Z z z Z z tf NJ* tf s? S? 3? ^ s^ >R m-i vO VC CM o o o o o o o o o c o o o 2; 2 Z Z Z Z Z Z Z Z Z Z Z St v^f i ^ ^° S£ S90 \=C S£ 35 o vO VO o o o o o O o o o o o o o - Z Z Z Z Z Z Z Z z Z z z Z St St st St X s^ S£ \o o VO \o vO o Vtl QQ o o o o o o o o o c o o G z Z Z Z Z Z Z Z Z Z Z Z z ■St no CM - -st 00 CM Q -st X "T 1 CM 1 CM CM 4 1 cj TT •sr i c ■*t- 00 CM :: V. -I \C o ■st X ii — ' CM CM ■1 CO CO -st ■st ■st &. 66 CONCRETE SILOS Recesses for Reinforcing Rod: — The reinforcing -is commonly- laid in the mortar between the courses of block, the strength of the mortar and the downward pressure of the blocks above being de- pended upon to keep the rods in place under loaded conditions. In the best practice, however, blocks are used which have a recess in the top face deep enough to accommodate the reinforcing rod. Recesses are generally put about two inches in from the outside of the block. ^=WC£\5 TO .»£• Tll-l£D MTH COMCKETE METHOD Or ANCH0R/H6 'OS tVHfA/ LAPPINCi Figure 51. Continuous door opening for concrete block silo. View shows the manner of fastening reinforcing rods to the door frames, also of anchoring rods around a block instead of lapping. Continuous Door Frames: — The frames for the continuous door- way are made in about the same manner as those placed in mono- lithic silos, as described on page 64. Two 6-inch 8-lb. channels of UNIVERSAL PORTLAND CEMENT CO. 67 a length equal to the distance be- tween the barn floor and the top of the silo are used. Holes to receive ^-inch rods are drilled on the cen- ter line of the channel at intervals of 12 inches, and holes of sufficient size to accommodate the reinforcing rods are drilled on a line 2 inches from one edge of the channel at in- tervals equal to the height of the block, which in most cases is 8 inches. The drilling should be done by the local blacksmith unless the farmer or builder has special equip- ment for doing this work. Great care should be taken to get corre- sponding holes in the two channels at exactly the same height and dis- tance from the edge. Bolts 24-inch in diameter and 2 feet 6 inches long, threaded for 4 inches on each end, should also be ordered from the blacksmith or made at home from 34-inch steel rod. Four nuts should be provided for each bolt. In assembling the frame one nut will be placed on each end of each rod 2 feet 2 inches apart. into the f-inch holes in the channel, and the other nuts put on, which will hold the channel and bolts tightly in place. The door-frame is then ready to be erected. The frame should be well braced until the walls are up far enough to hold it securely. As the reinforcing rods are laid upon successive courses of blocks, they are cut off long enough so that the ends will extend about one inch when brought through the channel. After being thrgsadecL, the ends of the rod will be brought through the holes, drilled to receive them, and the nuts will be put on, but not tightened sufficiently to disturb the rods in case they are laid in the mortar and not in recesses in the blocks. The doors should be made of 2x12" material in the same manner as those for monolithic silos as described on page 46 and shown in Fig. 33. Fig. 52. Mr, Fay Baldwin's concrete block silo, Greenfield, Ohio. Dimensions, 15$ feet in diameter, by 36 feet in height. Built during the summer of 1910. The bolts will then be slipped 68 CONCRETE SILOS Home-Made Blocks A NUMBER of farmers in various parts of the country have put up concrete block silos of blocks made during spare time with a block machine or a home-made mold. Good blocks can be made by either method, but the use of a machine quickens the work, and does it in a more uniform manner with the expenditure of a great deal less labor. Block Machine Manufacturers: — For the benefit of those who may wish to manufacture silo blocks with a machine designed for the purpose, the following list of manufacturers, who exhibited their machines at the Chicago Cement Show, is given. There are also, a large number of other machines on the market capable of making good silo blocks. Any of the following will be glad to send full information regarding their machines on request : The Anchor Concrete Stone Co., Rock Rapids, Iowa. Ashland Steel Range & Mfg. Co., Ashland, Ohio. Cement Machinery Co., Jackson, Mich. Century Cement Machine Co., Rochester, N. Y. Hayden Automatic Block Machine Co., Columbus, Ohio. Hobbs Concrete Machinery Co., Detroit, Mich. Ideal Concrete Machinery Co., South Bend, Ind. Inman Concrete Block Machine Co., Beloit, Wis. Marsh Co., Old Colony Bldg., Chicago. Miles Manufacturing Co., Jackson, Mich. Multiplex Concrete Machinery Co., Elmore, Ohio. Somers Bros. Manufacturing Co., Urbana, 111. U. S. Gas Machine Co., Muskegon, Mich. : I i—i Figure. 53. Home-Made Silo block mold. UNIVERSAL PORTLAND CEMENT CO. 69 Home-made Molds: — The mold shown in Figure 51 is a modifi- cation of that used by Wm. Stoll of Lansing, Mich., to construct blocks for his silo during the summer of 1907. It can be used to make blocks of any length up to 24 inches and of any width up to 8 inches. The height of the blocks may be 8 inches or less. The mold can be made from a piece of old railroad tie 30 inches long, 8 inches wide and 6 l / 2 inches high sawed on the arc of a circle, with a diameter 4 inches greater than that of the inside of the silo. One-half-inch holes are drilled \]/ 2 inches from each end to receive 18-inch bolts, by which the sides of the mold are held at the desired distance apart. The end pieces are made of 1-inch planed lumber and have tapered wooden blocks 8 inches long, 5 inches wide and ^-inch thick screwed to them for the purpose of making end cores on the blocks. The end pieces are held in place by wedge-shaped wooden blocks inserted between them and the bolts. If hollow blocks are desired, the air spaces may be provided by cores made of tapered 4x4" pieces. The inside of the mold should be well greased before use to prevent the concrete from sticking. Size of Block: — Although concrete blocks are made in a large variety of sizes, those most commonly used in silo work are 8 inches high, 8 inches thick and either 16 or 24 inches long, with half and quarter lengths as required. Blocks of these sizes are recommended as preferable to those less than 8 inches in height which require more labor to lay, or blocks more than 8 inches in height which are un- handy because of their weight. Fig. 54. Concrete silo and dairy barn, University of Nebraska Agricultural School, Lincoln, Neb. Construction of this type is frequent among the state agricultural colleges ; fully a score have concrete silos. 70 CONCRETE SILOS Commercial Concrete Block Silos ,,. ■ THE PERFECT SILO:— The Perfect Silo, built by the Perfect Reinforced Silo & Cistern Block Company, of Delaware, Ohio, has met with great favor amongst Ohio farmers and a large number have been put up in Delaware and adjacent counties. Some of these silos have been built by the owners with block purchased from the above company. This system differs from all others in the dimensions of the blocks and the method of reinforcing. The blocks are made on an arc, 24 inches long, 12 inches high, and 4 inches thick. Each block is reinforced with two iron bands running lengthwise 6 inches apart. Each rod is looped and turned 6 inches from each end. These loops are spaced so as to correspond with }^-inch round vertical holes which are formed in the block. When the blocks are laid in the wall these vertical openings are filled with cement and water grout and steel dowel pins are passed through this soft material and inserted about half way in the block below. The rods should be of such length that they will reach up about half way in the blocks above. The blocks have a groove y 2 inch deep in the top edge which provides space for a larger mortar bed and also for the heavy horizontal rods which span the continuous door openings at intervals of 2 feet. These rods are firmly fastened to the vertical dowel pins. The dowels next 600.0 UJCKBU Fig. 55. Two large monolithic silos on tire Jelke Dairy Farm, Dundee, 111. The combined capacity of both silos is nearly 600' tons.-- The silo on the c left was built, by a contractor, and thaton the right by farm laborunder the direction of Mr^.W. A. Dickinson, the farm superintendent. Both silos have concrete roofs. UNIVERSAL PORTLAND CEMENT CO. 71 to the door openings are made of heavy pipe in 4-foot sections firmly screwed together. This system is shown in Figures 56 and 57. t, J! Fig. 56. Detail of Lateral and Perpendicular Reinforcing in the Perfect Silo. Fig. 57. Sectional View showing Construction of the Perfect Silo and Method of Reinforcing continuous Doorway. 72 CONCRETE SILOS The Zeeland Silo: — A very interesting type of concrete block silo is being used extensively through the region between Holland and Grand Rapids, Michigan, which is known as the Zeeland silo and has been built exclusively by Mr. Chris Dejonge, of Zeeland, Mich. About 30 Zeeland silos have been put up by him in Ottawa County alone. The Zeeland silo has a number of unique features. It is the only silo of its kind using solid blocks made "tongue and groove" so as to fit any diameter of silo. The blocks are made 24 inches long and 8 inches high and have a thickness of only 3 inches. They are laid up in 1 :2 cement and sand mortar and the inside of the wall is plastered off with mortar of the same proportion. Rein- forcing consists of a heavy iron rod around each course, laid in a groove provided in the top of the blocks. Early silos of this type were reinforced with band-iron hoops 2 inches wide by ^4 mcn thick placed four courses apart. The silo of Mr. Simon Wierda shown on page 54 was the first one of this type constructed. Mr. Dejonge has lately (April, 1911) secured patents on a semi- circular steel chute and ladder which is placed on the inside of the silo. This permits the silo walls to be built up full all around, the only opening necessary being a door in the bottom. The chute is held to the silo wall by means of hooks and eyelets, the latter being placed in the wall at the time of building. When it is desired to use off the silage, two top sections of the chute are removed, and as the height of the silage is lowered successive sec- tions are removed and hung two spaces higher. Fig. 58. Large monolithic silo, built by Cornelius Andre, Grandville, Michigan. Cost of materials, $82.00; cost of labor, $108.00; total cost of silo, $190.00. Mr. Andre has many creditable examples of concrete work about his place, includ- ing barn floor and dairy house. The silo shown above is admired by all of the farmers of the vicinity. UNIVERSAL PORTLAND CEMENT CO. 73 Concrete Chutes A PERMANENT chute of concrete is a valuable adjunct to any concrete or masonry silo. The same arguments presented for the concrete silo stand for the chute. The concrete chute is substantial and permanent, fireproof and cold-proof, and it greatly improves the appearance of the silo. Size of Chute: — Chutes in use in various parts of the country vary in size from 2 feet square to about 5 feet square (inside dimensions), but the former size is much too small and the latter larger than need be. For the average monolithic silo a chute 3 feet by 4 feet in inside di- mensions is recommended. The outer dimensions will then be 4 feet by \y 2 feet, the walls being 6 inches thick. A monolithic chute of this size will require one-third of a bar- rel of cement, % cubic yard of sand and 1/5 cubic yard of gravel, per foot of height. For the block silo, the size should be such as will be accommodated by whole and half blocks. The outer dimensions of a hollow block chute (using 8x8x16" blocks) should be 4 feet 8 inches square, making the inside dimen- sions 3 feet 4 inches by 4 feet. This size will require 9^ blocks for each course. Foundations: — The foundation for the chute should be 2 feet wide and 1 foot high, the same as that for the silo, using concrete of the same proportions. (See page 36.) — ~ .~~— built j^-inch vertical reinforcing rods must be imbedded in the foun- dation 18 inches apart. Monolithic chute walls may be built up simultaneously with the silo walls, but it is much more convenient to build them after the completion of the latter; chute walls of concrete block must be built at the same time, being built in and kept at the same level as the silo walls. Monolithic Chutes: — The accompanying illustration shows forms in position for building a monolithic chute. Two-inch planed lumber should be used for the face of the forms, and 2x4's for the vertical braces. The steel rods used to hold the forms together should be 24 inches long, threaded for 4 inches at each end. Each section of the form should be about 2 feet (4 plank) high. To raise the forms the lower rods are withdrawn and the holes made by them cemented Fig. 59. 165-ton silo of A. R. McNeill. Wil- low Wall Poultry Farm, Old Fields, W. Va. Cost, complete with concrete chute, $405. Built by R. C. Angevine, Coldwater, Mich. If a monolithic chute is to be 74 CONCRETE SILOS up. The wooden braces are then raised, and the lower panels of planks placed above the others. The method of joining the chute to the silo is shown in the figure. Two 1x6" boards, with edges slightly beveled to permit of easy- removal, are placed in a vertical position on the inside of the outer silo form, 3 inches to each side of the line of the doors. In this manner recesses "a" are produced. Three-eighths inch rods 30 inches long, spaced at intervals of 18 inches, and bent as shown by the dotted lines in the figure, are used to hold the chute securely to the silo. The most convenient way to put in these rods is to have them lightly stapled to the boards occupying recesses "a." This will hold the rods in position until the concrete is placed. The forms and vertical boards may be moved as soon as the walls have hardened sufficiently, and the ends of the rods bent up into a horizontal posi- tion. Where windows are desired in the chute, the openings may be made with a form similar to that used for making non-continuous door openings, shown on page 48. The horizontal reinforcing of the chute should consist of ^-inch round reinforcing rods so spaced as to correspond with the rods binding the chute to the silo, so that they mav lap with the latter. The lap should be 24 inches long. Two horizontal rods should be placed over all windows. Short oblique rods, 24 inches long, should be put in about the corners of all windows, at an angle of 45 degrees, as a protection against diagonal cracks running from the corners of the windows. Jl>?ooa-|8"A p »«'■»• Block Chutes:— If the block silo and chute are put up si- multaneously the walls of the two will be held together by the blocks, and no reinforcing will be necessary. Window openings in the chute may be made by using concrete sills and lintels, which are easily ob- tainable from block dealers. A length of heavy strap iron may be substituted for a lintel, if desired, and the sill cast in place by means of a sim- ple box mold. Fig. 60. Forms for monolithic concrete chute. The illustration shows the recesses "a" and the %-inch re-info rcing rod used in joining the chute to the silo wall. UNIVERSAL PORTLAND CEMENT CO. 75 5£CT/OM THROUGH S/LO Fig. 61. Sectional view of a monolithic silo equipped with water supply tank, roof and chute of concrete. The small view shows section of the rectangular chute. 76 CONCRETE SILOS Water Supply Tanks THE top of a monolithic silo is a convenient place for the farm water supply tank; in fact, if one were about to build a large concrete tank, no better construction could be chosen than that of building the base in the shape of a monolithic silo, whether it could be put to any other use or not. Where both silo and tank are necessities, as on large stock and dairy farms, the two may well be combined. Size of Tank: — Every farm should have a water supply tank large enough to take care of all the needs about the house and barn and still leave a reserve for use in case of fire. Table N shows the capaci- ties of tanks advocated for silos with diameters of from 8 to 16 feet, as- suming the tanks are filled to a height of five feet. It is hardly practical for inexperienced persons to build tanks of greater diameter than 16 feet, erected on top of silos, unless these tanks are especially de- signed for each particular silo. De- tailed plans of larger tanks will be designed by the Information Bu- reau, however, to fit individual cases and will be furnished upon re- quest. Planning for the Tank: — If a tank is to be built on top of the silo, due attention must be paid to this fact in planning the reinforcing for the walls. Thus, if it is desired to build a silo 40 feet in height with a tank 6 feet in height on top, the silo should be reinforced in the same manner as though it were 46 feet in height without any tank. From the floor of the tank to the top, the reinforcing will be put in according to the diagram on page 77. Bridging Across Continuous Doorways: — In silos with continu- ous doorways, it is necessary to bridge across the top of the door- way before laying the tank floor. The djoor-frame should extend up within one foot of the bottom of the floor, and as soon as the walls have been built up to the level of the top of the frame, a rein- forced concrete beam 12 inches high and 4 inches wide should be put in, at least 3 T / 2 feet long so as to give a bearing of one foot or more on each side of the opening. This beam should be reinforced with four 3/2-inch round rods, and may be made in a small mold-box, without top or bottom. It should be placed in the inner side of the wall and the concreting then resumed up to the level of the tank floor. Fig. 62. Monolithic silo, built for the Agri- cultural Guild of the University of Chicago by J. H. McCoy (Steel Concrete Construc- tion Co., successors', Harrisville, Pa. This silo is 47 feet in height, and contains a 250- barrel water tank within the top four feet. UNIVERSAL PORTLAND CEMENT CO. 77 Diameter of tank in ft. TABLE N CAPACITY OF WATER SUPPLY TANKS Capacity in barrels 8 60 10 95 12 135 14 185 16 240 *Depth of water — 5 feet. One barrel equals 31.5 gal. or 4.21 cu. ft. DIAMETER OP TANK I * 1 U I *fr 5 Ft j£& 8 ft. 10 ft. 14 ft. 16 ft. inch SIZE OF ROUND RODS T ^ 3 V roto to inch inch I Ft 2 Ft. 3rt 5Tt [er^ 78 CONCRETE SILOS The Floor: — As soon as the wall has been brought up to the level of the tank floor, the outer form should be raised one foot and the inner form lowered one foot. A heavily braced platform which will support the concrete floor should then be erected upon the inner form. The floor form must be made of 2-inch planks sup- ported on 2x10 inch girders, braced to the staging" as well as to the inner form, which must be strengthened if much of the weight of the floor is to rest upon it. The floor form must be able to support a load exceeding 125 pounds to the square foot in the case of a 16-foot silo, or 75 pounds to the square foot for an 8-foot silo. The great- est caution must be exercised in getting the framing put up in such manner that it will carry the load without danger of collapse. The entire floor must be con- creted at one operation. The necessary materials must be on hand, and provision made for mix- ing in large batches and elevating as speedily as possible. These are points which are absolutely essen- tial for perfect work. The con- crete should be made in the propor- tion of one sack of cement to 2]/2 parts clean, coarse sand, and 4 parts of screened gravel, the latter to contain no particles smaller than y^ inch. The concrete must be thoroughly mixed with water enough to flow with slight agitation. The following table shows the thickness of floor, amount and spacing of reinforcing and the amount of materials needed for tank floors of various sizes : Fig. 63. 150-ton Monolithic silo of August Tillstrom, Kings Landing, near Sodus, Michigan. This silo is 14 feet in diameter and 47 feet in height and has walls varying in thickness from 9 inches at the bottom to 6 nches at the top. H. G. Burbank, Eau Claire, Michigan, was the contractor. Cost complete $300. TABLE O. MATERIALS AND REINFORCING FOR TANK FLOORS Diam. Total Cement req'd. bbls. Sand Gravel Pounds of -^ inch round Pounds of ■Sc- inch round Spacing of and thickness req'd. req'd. No. of reinforcing tank of cu. cu. reinforcing reinforcing lengths rods of silo floor yds. yds. rods req'd. rods req'd. (inch, apart") 8 6 in. f 1.3 .48 .77 96 16-16' 6 in. to 8 in. 10 7 " 2.4 .87 1.4 193 32-16' 4 « »g " 12 &A " 4.2 1.52 2.5 407 38-16' 5 " "8 " 14 10 " 6.7 2.42 3.9 492 46-16' 5 " "8 " 16 10 " 8.7 3.17 5.1 685 82-16' 4 " "g " Before placing any of the concrete, reinforcing rods for the floor should be laid down upon the platform, as shown in Figure 64. Begin to lay the rods at the center, at the closest spacing shown in the table, then lay the remaining rods running the same direction, working to the wall where the greatest spacing shown in the table UNIVERSAL PORTLAND CEMENT CO. 79 may be used. The reinforcing should then be placed in the other direction in the same manner, and wired at intervals of 2 or 3 feet with ordinary hay-baling wire. The ends of the reinforcing should be long enough to extend up into the wall at least two feet, being joined to the horizontal wall reinforcing. The reinforcing should be supported about an inch above the platform, on small cubes of concrete or strips of wood placed about 2 feet apart. 1:3 cement and sand mortar should then be- put put on and worked under the reinforcing to a depth of about one inch, and the concrete immediately placed upon this. In case small wooden strips are used to support reinforcing, these may be with- drawn from the underside of the floor as soon as the framing is removed, and the resulting holes filled with mortar. Concrete cubes are preferable to wooden strips, and may be easily made in the fol- lowing manner: Lay down two 1-inch boards on a flat floor, one inch apart, and fill in the space between them with 1 :3 mortar, trowelling off the top. The long strip of concrete thus formed may be broken up into short sections approximately cubical in shape. Continuing Walls: — After the floor has sufficiently hardened, the forms and scaffolding should be taken down, the wall forms hoisted up the outside, and placed in position on the tank floor. Fig. 64. Showing the method of placing reinforcing rods in the tank floor. Before concreting is continued on the walls, the surface must be cleaned off, thoroughly moistened, and painted with cement and water grout, mixed about as thick as cream. The concrete must then be placed before the grout shows any tendency to dry. Six feet will be found a convenient depth for the tank. 80 CONCRETE SILOS In large supply tanks, where the water is continually agitated, water seldom freezes sufficiently to damage the tank. However, it is much safer to build the tank with a slight batter all around, that is, making the inside diameter greater at the top than at the bottom. The inside line of the wall should slope outward one inch for every foot in height. Ice in forming expands and rises upward, and the batter thus relieves the pressure which would otherwise be commu- nicated to the walls, possibly injuring them, in the case of a hard freeze. Reinforcing: — The vertical reinforc- ing above the tank floor is put in the same as below, with £-inch rods, spaced at intervals of 3 feet around the circumference. The spacing - for the horizontal rods may be obtained from the diagram, on page 77. By re- ferring to the diagram, it will be seen that the vertical scale shows the distance from the top of the tank, each small division representing one inch. Across the top of the table are the tank diameters, running from 8 to 16 feet. The heavy black lines indicate the spacing of the rods. This diagram (page 77) may be conveniently used for tanks six feet deep or less. Fig. 65. Concrete block silo of C. D. Ames, Kaneville, 111. Diameter, 16 feet ; height, 44 feet. Built in 1910 from block manufactured by F. W. Merrill, Kaneville. Example : — Suppose it is de- sired to know the proper reinforc- ing for a tank 14 feet in diameter and 6 feet deep (to hold 5 feet of water net). Running across the top horizontal column until 14 feet is reached, we find (directly below) that two sizes of rods— ^ inch and % mcri — are used. Running to the bottom of the vertical dia- grams, it will be seen that a ^-inch rod is placed 2 inches from the floor line. The next two rods are also ^-inch, spaced 7 and 14 inches above the first rod. Above this point %-inch rods may be used to the top, as shown, or three more ^g-inch rods may be used, and the change made to %-mch r °ds at a point 2 feet 5 inches from the top. Piping and Overflow: — The intake and outlet pipes should run up one corner of the chute, far enough from the wall so that they may be covered to prevent freezing. The overflow outlet may con- sist of a 3-inch pipe passing through the wall about 6 inches below the cornice. This pipe may be run down within the chute or on the outside of the silo, and led to a line of tile. In many cases, how- ever, the pipe is simply made to stick straight out of the wall about a foot, and the overflow is not drained off in any way. This method is not recommended as a general thing, but may be suitable if close watch is kept so that the tank is rarely filled to the overflow point. UNIVERSAL PORTLAND CEMENT CO. si The Concrete Roof THE functions of a roof on a silo are (1) to prevent the cold from reaching the silage and (2) to make it more convenient to work in the silo during stormy weather. Many farmers and contractors do not consider a roof necessary and in moderate climates this is probably so; all will agree, however, that in sections of the country where the tempera- ture goes below zero a roof is a positive necessity, as well as a great convenience under any circum- stances. The logical way to finish up a concrete silo is with a concrete roof. Of 110 concrete silos recently in- vestigated by this Company, 39 had concrete roofs, 30 wooden roofs, 3 steel roofs, 13 had no roofs of any sort, and on 16 silos no note of the roof was made. Of the silos with concrete roofs, 39 wooden roofs, 3 were built during the last two years, showing that the tendency at the present time is toward the all-con- crete silo — from foundation to pin- nacle. If the directions given in the following paragraphs are closely followed, little difficulty will be found in putting on a good roof of concrete — one that will last in- definitely without need of being shingled or otherwise repaired, and which will be in no danger of blowing off. The Cornice: — A cornice is only necessary where a roof is to be put on, its chief uses being to prevent water from the roof from running down the walls, and to improve the appearance of the silo. Figure illustrates how the forms are made for the cornice on a monolithic silo. The brackets for the forms are made of }4" x2 " stra P iron bent as shown, and drilled to receive three stove bolts. These brackets should be placed on the outer form at intervals of about 6 feet, holes being drilled at the proper points to receive the stove bolts. The bottom of the cornice mold box is made of 2"x6" planks in short lengths, sawed to the arc of a circle with diameter 1 foot larger than that of the inside of the silo. The side of the mold is made of l"x6" planks spiked to the bottom boards. The mold is held in place by screws through the bracket, as shown. An extra band of horizontal reinforcing is put in the cornice, as may be seen in the figure. The vertical rods in the silo walls and the radial rods of the roof are all brought around the horizontal reinforcing in the cornice, thus holding it in place and strengthening the cornice. Fig. 66. 100-ton concrete block silo of John Berts, Geneva, Wis. Built by owner in 1909. Cost, S500.00, complete. Blocks are 20 in- ches long, 6 inches high, and 8 inches thick. 82 CONCRETE SILOS £ Half round CStoi/eBo/fo For the top section of the wall (last filling of the forms) the inner and outer forms are brought up to the line of the top of the completed wall. The forms are then filled to within one foot of the top, the outer form removed, and brackets attached. (If the stove bolts are already in place the form need not be removed to attach the brackets). The mold box will then be put in place. The cor- nice will be concreted at the same time as the roof, as will be ex- plained later. Roof Framing: — The roof framing may consist of two-by-fours or similar material, resting on the top of the inner wall form as shown in the sectional view, and the lower left-hand quadrant of the plan view, Figure 68- In case of a silo with a water tank on top, the forms must be removed before the roof framing is put up, and the latter supported on a light framework erected within the tank. The roof frame may be boarded up as shown in the plan view, with boards running either rad- ially or otherwise, as desired. These boards should be placed ^Mfx 2." Bracket close tog-ether to prevent the concrete from, coming- through when placed upon them. Table P shows the vertical rise to be given to roofs for silos of various diameters. A hole about 2\ feet square must of course be left for filling the silo, or if a roof covers a tank the hole will afford access to the latter. Before placing the reinforcing or the concrete the top of the framing should be covered with old newspaper, building paper, or similar ma- terial, which will prevent the concrete from sticking to the forms. This will greatly facil- itate their removal. Placing the Reinforcing: — The lower right hand quadrant of the plan and the sectional view show the spacing of the radial and hoop reinforcing. The former is placed so as to be one Box for Cornice l ooi a P art ? n * h * c ^ rcum - ference, and the latter so Fig. 67. Mold box for Silo Cornice that the distance between the rorms in place for Top section and Cornice UNIVERSAL PORTLAND CEMENT CO. 83 Fig. 68. Reinforced concrete roof design. The wooden framing is removed as soon as the cover has become thoroughly hardened. 84 CONCRETE SILOS three bottom hoops is 6 inches, between the next three hoops 9 inches, and between all remaining hoops 12 inches. Extra rods should be put in around the window opening if the regular rods do not follow the outline of the window closely enough to reinforce it. All intersections must be wired together, and the outer ends of the radial wires brought down and bent around the horizontal rein- forcing - in the cornice, as shown. The reinforcing - should be sup- ported one inch above the roof frame, so that when the concrete is put on, the rods will rest on a one-inch bed and be covered by a three-inch bed, the total thick- ness of the roof being four inches. For amounts of reinforcing ne- cessary for roofs of various dia- meters, see table P. Concreting : — Concrete for the roof should be made in the proportion of one sack of cement to two cubic feet of coarse, clean sand, to three parts of screened gravel. The concrete should be mixed as wet as it can be put on without danger of running to the edges of the roof due to the pitch. The top should be trowelled off smooth, in the same manner as a sidewalk. Concreting should begin at the cornice working around the roof, so as to keep the concrete on all sides at an even height. As the work progresses toward the center a broad board, on which to stand, may be laid on the concrete already laid. It will also add greatly to the safety of the men working on the roof if a rope attached to the pinnacle is tied about the waist of each. In place of this, it is often desirable, for the sake of greater safety to the workmen, to put up a scaffolding on the outside of the silo. Special care must be taken to protect the roof from sun, strong wind and freezing until thoroughly hardened. For this purpose a cover- ing of straw, manure, or canvas is generally effective; if either straw or manure is used it may be necessary to weight it down. The effect of sun and wind is to dry the concrete out too rapidly, causing checking and cracking; frost affects the strength of the con- crete and is otherwise objectionable. Monolithic Roofs for Hollow Block Silos: — Where it is desired .to put a monolithic concrete roof on a hollow block silo, the wall should be laid up in the usual manner until the third course of block from the top is reached. The blocks used in this course should be Fig. 69. Block silo of Col. Fred E. Shubel, Syca- more Farm, Lansing, Mich. Diameter, 12 feet; height, 38 feet. Cost, complete, about $180.00; capacity, 94 tons. Bevel faced blocks were used, and the inside finished -with 1:2 cement and sand mortar. CONCRETE SILOS 85 TABLE P DIMENSIONS AND MATERIALS FOR ROOFS For Silos with Diameters 8 feet to 22 feet Diam- Vertical Rise Volume of concrete Cement required Sand required Stone required J Inch Reinforcing Rods eter of No. of Stock No. of Silo in cu. bbls. cu. yds. cu. yds. rods length pounds yards required of rods of rods 8 ft. 2 ft. 0.63 1.09 0.33 0.49 26 10 ft. 42 10 " 2U " 1.01 1.75 0.52 0.78 31 12 " 62 12 " 3 " 1.49 2.59 0.77 1.15 33 16 " 88 14 " 3V 2 " 2.05 3.56 1.07 1.58 45 16 " 120 16 " 4 " 2.71 4.72 1.41 2.08 87 10 " 146 18 " 4 " 3.34 5.80 1.74 2.57 93 12 " 187 20 " 4 " 4.11 7.15 2.13 3.1/ 107 12 " 226 22 " 4 " 4.93 8.55 2.56 3.80 113 14 " 265 Concrete for roofs is made of 1 sack Portland Cement to 2 cubic feet of coarse sand to 3 cubic feet of stone. Each cubic yard of con- crete requires 1^4 bbls. of cement, V 2 cubic yard of sand, and % cubic yards of stone, approximately. The ^4-inch reinforcing rod weighs .167 pounds per lineal foot. solid, namely, made without cores, or if with the cores these should be filled up with mortar. The last two courses of hollow block should then be laid, the cores being left open. Fig. 70. Cornice block for concrete block silo. Special cornice blocks should be cast to make the cornice pro- jection, and for this purpose a mold similar to that shown in Figure 53 can be conveniently used. The block should be 14" in width and of the same length on the inside of the wall as the wall blocks. The portion of the cornice blocks directly above the wall blocks should be 6" thick, while the projecting ends of the blocks should be but 5" thick, so as to give a one-inch drop. The roof framing is then put up in the same manner as described on page 82, but in this case it must be supported by the scaffolding instead of on the inner form mentioned there. The reinforcing is placed in the same man- ner as described on page 82 and shown in Figure 68, excepting that the outer ends of the radial rods are made to extend down through the holes in the block for a distance of a foot or more. Since the holes in the third course of block from the top were either omitted or filled up before these blocks were laid, holes in the two upper courses can be filled up with wet concrete as soon as the reinforcing rods are in position. The roof is concreted as described on page 84. Before the concrete is placed on the cornice blocks this must be moistened and painted with a cement and water grout. 86 CONCRETE SILOS Fig. 71. William Stoll's block silo, near Lan- sing, Mich. The blocks were made by the owner upon the concrete floor of his dairy barn, and laid up a row at a time, as he had an opportunity. The estimated cost was $137.50 including labor; capacity 67 tons. One of the first concrete silos in Ingham county. Fig. 72. Mr. Frank Bennett's concrete block silo, East Troy, Wis. 8-in. by 8-in. by 20-in. rock face block were used, these being ob- tained from a local dealer. This silo holds 143 tons and cost $340. The roof is of sheet steel. The contractor was Albert Elbert, of East Troy. Fig. 73. F. W. Merrill's concrete block silo, Kaneville, 111. Made with patented block manufactured by Mr. Merrill. Cost, $450; capacity, 160 tons. This silo was put up complete in 4 days. Fig. 74. C. Shaw's monolithic concrete silo. New Augusta, Indiana. UNIVERSAL PORTLAND CEMENT CO. 87 Booklets for Free Distribution. CEMENT DRAIN TILE. An illustrated thirty page booklet embracing the results of an in- vestigation into the durability of cement drain tile. CONCRETE SURFACES. A thirty-two page booklet describing various methods of concrete surface treatment with information as to cost and illustrating repre- sentative concrete surfaces in colors. CONCRETE SILOS. An eighty-eight page booklet on silage and the building of concrete silos, containing complete directions as to construction, photographs, drawings, and cost data. CEMENT STUCCO. An illustrated pamphlet on cement stucco containing specifications and table of colors to be used in cement plaster. CONCRETE CHIMNEYS. A report of an investigation made by Sanford E. Thompson. CONCRETE POLES. A comprehensive discussion of the subject of reinforced concrete poles prepared by R. E. Coombs and C. L. Slocum. CONCRETE PAVEMENTS. The history of their use in this country, their cost and construction, with specifications. PORTLAND CEMENT SIDEWALK CONSTRUCTION. By C. W. Boynton; sets forth the requirements for good concrete sidewalk construction and how to obtain the best results. It contains specifications for cement sidewalks and table of sidewalk practice in the principal cities. CONCRETE IN THE COUNTRY. One hundred and twelve pages of simple instructions for building farm structures of concrete. CONCRETE SILOS Booklets for Free Distribution (Continued) STANDARD SPECIFICATIONS AND UNIFORM METHODS OF TEST- ING AND ANALYSIS FOR PORTLAND CEMENT. Embracing report of the Committee on Standard Specifications of the American Society for Testing Materials, the report of the Com- mittee on Uniform Tests of the American Society of Civil Engineers and the report of the Committee on Uniformity and Technical Analysis of the Society for Chemical Industry. THE MANUFACTURE OF UNIVERSAL PORTLAND CEMENT. A brief pamphlet descriptive of the process of manufacturing Uni- versal Cement. MONTHLY BULLETIN. A twenty page monthly periodical describing the more important work in which Universal Portland Cement is used, with announce- ments, notes and brief articles of timely interest. FARM CEMENT NEWS. A periodical on the use of cement for the progressive farmer. No. 3 — "Selecting and Mixing Materials for Concrete." No. 4 — "Concrete Walks and Floors." No. 5 — "Concrete Foundations." No. 6 — "Concrete Troughs and Tanks." No. 7 — "Concrete Line Fence Posts." No. 8 — "Concrete Corner and End Posts." No. 9 — "Concrete Building Blocks." No. 10 — "Concrete Walls." We maintain an Information Bureau for the purpose of assisting our friends and customers in new problems involving the use of concrete with which they may meet. Our advice and help is free for the asking and involves no obligation whatever. We will be glad to have you write us requesting information about any point. Your inquiry will receive our prompt attention. Write to the nearest office of the Universal Portland Cement Co., Chicago Pittsburgh Minneapolis 72 West Adams St. Frick Building Security Bank Bldg. The Crown Press, Chicago tf One copy del. to Cat. Div. OCT 30 1911 AUG 25 I&11 i: ::4 B |j LIBRARY OF C ^^., 002 766 093 9 Samplin Universal Portland Cement four hun- dred and fifty times an hour as the finished product leaves the mill is one illustration of the thorough- ness alfcd care exercised at every stage in its manufacture. Our method of obtaining fair samples by means of an auto- matic device which removes from the convey- ing belt entering the storage bins a certain quantity of cement every eight seconds, was originated and is employed exclusively by this Company. Universal Portland Cement Co, Chicago — Pittsburg Annual Output 10,000,000 Barrels