TH 4763 CORNELL UNlVfRSiTY UBRAms ITHACA, N. V i4853 ^e Arts Libtso^ BMey Hill ConcreteSwimmii and » Published by I :d Cement Association, TH .4763 C74 N FOREWORD "Few people appreciate how strongly swimming appeals to the rising gen- eration nor in how many ways it is beneficial and enjoyable. Swimming is to be commended for other reasons than the practical justification that it may some time enable one to save himself from drowning. In all climates it is one of the best of exercises. One can not observe a swimmer without being impressed with the strength, endurance and grace, and the even dis- tribution of his muscular development. To children and young people it is a most delightful and exhilarating recre- ation, for which there is no substitute. In promoting the general health and fortifying the body against colds, the swimming pool, especially the outdoor pool, and shower are well known. In the warmer climates, in addition to all these benefits, the swimming pool is a most agreeable means of keeping the body cool." From "Sanitation of Swimming Pools," California State Board of Health Monthly Bulletin (Sacramento, Calif.), March, 1919, by C. G. Gillespie, Director Bureau of Sani- tary Engineering, California State Board of Health. ^C Concrete Swimming and Wading Pools Advantages of the Outdoor Swimming Pool To many persons outdoor bathing is one of the most enjoyable of recreations. Indulgence in this sport is, however, often limited by lack of opportunity in the form of a natural body of water or swimming pool. Of late years park improvements in many cities have included outdoor concrete swimming pools, and their popularity has had much to do with the spread of the swimming pool idea, even as an adjunct to the private home grounds where the family can indulge in outdoor swimming often regardless of the season of the year. y *- «2i^*i(^r-^ i^~' -fflr^-- r:» ^ y:j^ -^ :-f . -f^'. -■-■iL :«-."■■_<. ■r,:--«i - "■*^i This concrete Kwimmine pool provides henlttif ill outdoor recreation and adds to the popularit.v o£ City Furli, Toledo. Ohio. It is not the intention in this booklet to treat of the indoor swimming pool, which is regarded as an essential feature of the modern clubhouse, but rather to present a few fundamental principles that should be observed in locating and constructing the outdoor pool so that all of its advantages may be realized. An examination of the illustrations in this booklet wilf impress one svith the wide range of design that may govern in the construction of a 4 CONCRETE SWIMMING AND WADING POOLS swimming pool, and will also suggest that such a structure may be simple and therefore of moderate cost. The circular or oval type is particularly adapted to public pools. It resembles a small lake with sides gradually sloping from the beach to a deep section in the center. The maximum shallow water space which is provided tends to reduce the overcrowding so common in public pools due to the fact that about 75 per cent of those using them do not swim. A diving platform at the center gives open space for the swimmers, as only those who can swim are able to reach it. The large beach area is another important feature; furthermore, it is impossible to fall into deep water from the shore. This pool at the Cranrl Hotel, Mackinac Island, MIchlean, Is Ofty tcot above Lake Mlchtean and Is a popular spot because the lake Is too cool for bathioB, A tea garden and dance Dlatform are located on the upper side or the pool. Financing Public Swimming Pools In many cases the financing of public swimming pools is an important problem. The larger cities usually have a budget to cover such con- struction; the smaller ones often have to resort to other means to build and maintain a pool. Public Subscription: The subscription plan for financing public or semi-pubhc projects has probably been used more than any other As an example, Dayton, Colo., in 1919, arranged to build and maintain a 60 by 90 foot pool with funds obtained through subscriptions from the business men of the town. Glendive, Montana, also secured a pool in 1921 by varying this method in utihzing volunteer contributions of labor and materials. CONCRETE SWIMMING AND WADING POOLS 5 Bond Issues: Sometimes it is possible to provide funds for building and maintaining a pool through the issuing of bonds. Des Moines, Iowa, adopted this plan and provided $350,000 to carry out a swimming pool project. Membership: This plan consists of selling memberships at a good rate to secure the necessary funds. Members are entitled to perpetual free use of the pool. Current expenses are met through revenues obtained by making nominal charge to non-member users. Attractively arranged surroundings add to the enjoyment by the Lynchburg, Vii., Country Club of its concrete swimming pool. Private Enterprise: Often in small towns some private individual can be interested in financing a pool and operating it as a personal business enterprise, the necessary revenue being obtained from fees charged for use. Later, if so desired, the pool may be taken over by the town. In Pilot Point, Texas, a 35 by 65 foot swimming pool, as well as a wading pool, is being operated in this manner. In this par- ticular case the charges are 35 cents for adults and 10 cents for children. Of course, charges must be determined by local conditions. Sanitation Maintenance of thoroughly sanitary conditions means much to the popularity of a swimming pool. The following items are extracts from CONCRETE SWIMMING AND WADING POOLS Concrete swimming pool built at Berkeley, Calif., by University of California, and conforming to requirements of the California State Board of Heultli. rules adopted by the California State Board of Health and suggest the most important measures: "All water in the pool and applied to the pool shall be con- tinuously safe hygienically. "This requirement may be met by the following methods: Continuous addition of new water (800 to 2,000 gallons per bather per swim); recirculation; ozonation, ultra violet ray, etc.; intermittent application of disinfecting solutions direct to the pool. Copper sulphate is recommended for algae con- trol, but not for disinfection. "All the water in the pool shall be continuously clean and clear enough that bathers may be distinctly seen on the bottom in all parts of the pool. It shall be free of noticeable suspended or floating objects or particles, scum or sputum. "This requirement may be met by (a) continuous inflow of new water; (b) fill and draw method; (c) recirculation method, whereby the pool contents are pumped from the pool, filtered and returned to the pool. Copper sulphate treatment is an important adjunct to this method." This bulletin, which is known as Special Bulletin No. 33, may be obtained from the California State Board of Health, Sacramento, and contains additional suggestions as to methods for increasing safety and cleanliness of swimming pools. Notes on Sanitation of Swimming Pools, prepared by the Portland Cement Association, may also be obtained on request. CONCRETE SWIMMING AND WADING POOLS 7 Selecting the Site In selecting a site for the outdoor swimming pool, a location should be chosen where natural drainage of the soil is good. Careful thought on the subject of location will suggest the many ways in which such a pool may be made to bear a harmonious relation to other structures or land- scape details of the home grounds. If desired, architectural adorn- ment in the form of a pergola, or departures from a plain square or rectangular plan may be made features of the work. These, although often pleasing, do not add to the utility of the pool, and might represent an expense that to some would be a bar to undertaking the construction. Concrete the Ideal Construction Material Concrete construction is ideal for swimming pools. It insures strength, watertightness, freedom from expensive upkeep, and permanence when properly designed and built. The prime essential of a swimming pool is that it shall be watertight. This can be attained with concrete by This oval concrete swimmine pool in Brookside Pnrl<. Cleveland. Ohio, provides recreation for about 1,4WI men and 60(1 women. using properly proportioned mixtures carefully placed and protecting the concrete after placing until it has hardened sufficiently to permit use. A high degree of sanitation is also desirable in a swimming pool. Well-made concrete is dense and impervious, hence a concrete swim- ming pool can readily be kept in sanitary condition. Although no surface finish other than that secured by spading the concrete carefully next to the face of well-made, smooth forms is necessary, nevertheless if another surface finish is desired, it can readily be obtained in a number of ways. CONCRETE SWIMMING AND WADING POOLS Some Desirable Details Where dressing rooms are not already available near the pool, suitable facilities must be provided. A shelter for this purpose may be a part of the architectural plan of the pool and its location, or may be a separate This inviting pool and ttie rustic cottage containing tlie dressing rooms fit the location nicely. A broad concrete walk around the pool is desirable. Turf wears away, dirt and gravel are unpleasant and pollute the pool, while planiis become slippery and must frequently be removed feature. The swimming pool itself requires few and simple furnishings or appointments. There should be a springboard a,t one end. Usually handrails or handholds are placed around the inside of the pool, slightly above water level. The season during which the outdoor pool may be used can be materially lengthened by providing facilities for heating the water. Steam coils may be placed along one or more sides of the pool, hot water or steam being circulated from a hot-water boiler or steam plant. E.xhaust steam where available is often suflBcient to warm the water to the desired temperature. Probably the simplest method of warming the water is to circulate it through a hot-water boiler. In such a case it is necessary that the boiler be set low enough in relation to the water in the pool so that the water will return to the boiler by gravity. A Suggested Design for Concrete Swimming Pool The center page illustration of this booklet suggests a design for a small rectangular swimming pool. If any change is made in the dimensions shown, it will be necessary, of course, to modify accordingly certain details of the design such as decreasing or increasing the quantity of reinforcing necessary, as the size of the pool is decreased or increased. CONCRETE SWIMMING AND WADING POOLS 9 For those who are not famih'ar with the general requirements of swim- ming pool construction, the following suggestions, relating particularly to the construction of the pool mentioned, are offered. Some Principles of Construction Walls of this pool were designed on the assumption that the soil has a bearing power of at least 4,000 pounds per square foot. If the bearing power is less, the footings must be modified accordingly. In excavating for the footings the trench should be made large enough so that after setting up the form for the exterior of the footing there will be sufEcient excavated space to receive the 6-inch concrete drain tile that is to be laid around the entire exterior of the footing. The lowest point of this drain should be connected with another tile line leading to a convenient out- let low enough to insure uninterrupted drainage. After footing forms have been set up and braced, reinforcing for the wall should be erected, being assembled by wiring at all intersections, and temporarily stayed in Swimming pool for semi-public, or community t Great Necli. a summer colony, near Kensington, N. V. position by supports placed above the footings. Reinforcing should also be temporarily secured to vertical supports so that it will remain correctly assembled and in proper position while concrete is being placed in the forms. The footings should be built up to the bottom of the fillet, at which level a notch 2 inches deep and 4 inches wide should be formed in the concrete by forcing a slightly beveled piece of 2 by 4 timber into the soft concrete and allowing it to remain until the concrete has hardened. The slight beveling will make removal of this strip easier. The notch or groove formed in the concrete will key the wall into the footing and increase the 10 < !^ ^ ^Tar Jojnf Lbcfder Sprinqboard I i^c X/3-0. ■5/ope floor foivard drain . ^u_.i I ja A -j- -f£qf/ng_ /lne_ -^ _ €^4" Sand or Discharge pipe. ' /3^0" ^ &" Concrete fi/e drain. i ''■^'t^:-;^!^"^ -£^4' t 1 -/o" or Sand c . ^ra\/el^-;^ 12 -5-4"- V—4L4'i- 3EC TioNA-A. Section b-B Section C-C. Suggested design for small 11 V(?/, 'Concrete wa/k around Cross Section Note: Pitch fop of yvall ^"foyvard oufs/de. /2 4m -/o'\^^ vsi M- «^ -4'4'- ^ M JK4i ^3^4- 3"^C T/ONP-D. 5ECTI0NE-E. concrete swimming pool. 12 CONCRETE SWIMMING AND WADING POOLS watertightness of this construction joint. In addition to the notch the concrete should be left level and roughened. Before the concrete for the wall is placed, the surface of the footing upon which the wall will rest should be scrubbed clean, drenched with water and slushed with a mortar composed of one sack of portland cement to two cubic feet of sand. This mortar coat should not exceed one-quarter inch in thickness and before it has hardened the concrete for the wall should be placed. Whenever work is stopped so that the concrete will have hardened before the next layer can be placed, the same precautions must be taken to insure a water- tight joint. Indoor concrete swimming pool in emi)loyes' club house of National Tube Co., Ellwood City. Pa. After the concrete in the footing forms is 24 hours old, forms may be removed and the lumber used for the wall forms, the forms being com- pletely built after the temporary supports carrying the reinforcing at the bottom of the fillet have been removed. The upper ends of the reinforcing should then be temporarily stayed to the forms to hold the rods in correct position while concrete is being placed. Wall forms should consist of sound lumber, planed to a uniform thickness, either tongued and grooved or with edges beveled so as to make tight joints and prevent leakage of mortar. Special attention should be given to bracing forms and to wiring them together to prevent any sagging or deformation. The upper ends of the reinforcing should then be stayed to the forms to hold it in correct CONCRETE SWIMMING AND WADING POOLS 13 position while concrete is being placed. Provision should also be made to hold the reinforcing at the proper distance from the face of the form. If only bank-run gravel is available the material must be screened by separating it into at least two parts, the sand being that material which will pass through a screen having 4 meshes to the linear inch, the pebbles being that rnaterial which will not pass this screen and which ranges from 34-inch particles up to those having a maximum dimension of 1 inch. The concrete mixture for the entire construction should be 1:2:3, which means one sack of portland cement to 2 cubic feet of coarse, clean, well-graded sand and 3 cubic feet of hard, clean, well-graded pebbles or broken stone. Any standard portland cement meeting the specification re- quirements of the American Society for Testing Materials will be suitable. Water used for mixing concrete should be clean and free from oil, alkali, acids, and vegetable or other organic matter. Enough water should be used to produce a concrete of quaky or jelly-like consistency. Mixing should be done by a batch mixer. Concrete should be placed in layers not deeper than 9 inches, each layer being well puddled with a rod and the forms rapped with wooden mallets. This helps to settle the concrete properly in the forms, com- pletely surrounding the reinforcing and working into difficult corners. It also tends to reduce air and sand pockets, and, by forcing the mortar against the forms, produces a dense, smooth watertight surface. If desired, the interior wall may be rubbed with a carborundum or similar stone. It is very important that the consistency of the concrete be as described. A mixture containing less water than that required for a quaky consistency would have to be tamped in the forms, and watertightness would not be certain to result nor would the desired bond or adhesion be secured between concrete and reinforcing metal; while if a sloppy mixture were used, cement would be washed out by the excess water and this would leave pockets around the reinforcing. Lumber of the quality previou.sly mentioned should be used for forms so that joints will be tight and the form face next to the concrete smooth. Forms should be well braced to prevent bulging due to pressure of the wet concrete. Under favorable weather conditions wall forms may be re- moved after 36 hours, but the back filling should not be done until the concrete is at least four weeks old, nor should the pool be filled with water for at least four weeks after the last concrete was placed. If there are any air or pebble pockets on the interior surface of the wall after forms have been removed, they should at once be filled with a 1 :2 cement-sand mortar. Concrete should be deposited in the forms within thirty minutes after it has been mixed. After half an hour, hardening action will have pro- gressed so far that if such concrete is used it will not develop its full strength. Concrete which has commenced to harden before being placed should not be retempered, that is, remixed by adding more water and turning the materials, but should be discarded. After wall forms have been removed the soil upon which the floor is to rest should be graded to proper level and slope, a 4-inch sand cushion placed and solidly compacted by rolling and tamping, and wedge-shaped 14 CONCRETEPSWIMMTNG AND WADING POOLS Mm. /2'0" & Ma)^.l3-0" Max.4-0" 8-0" to 9-0" Min. 12 JO" &r Max. 13-0" Iron band —^ h \. -i 5 00 — — °-- — — '-- "-- '--^ ^ 1 ■^ °--^ K 5?^ — , i ^\0"- / £"x4 J — P' L v/1 \A//i-h ^ space befyveen them. Plan and Elevation of Spring Board. /<£■" Z" _ 12" .^" ■Ring holf ■for rope. fr^-/- p:-:'-P': '-/O- -P/pe Details of Hand-Hold, /2" n/ua. Detail for Scum Gutter. Detail for Double Overflow Pipe. Suggested swimming pool details. CONCRETE SWIMMING AND WADING POOLS 15 wooden strips placed around the edge of the inner fillet to form the joint between floor and walls. The concrete for the floor should then be placed, reinforcing being laid 3 inches from the top surface as shown. The concrete should be struck off by using a wooden strikeboard and given its final finish by hand floating with a wood float. This plan contemplates continuous concreting of the floor. If it is impossible to carry on the work in this manner, provision must be made for joints that will make the floor consist of two or more slabs. After tv round of Kolf a plunge into a swimroinc pool is refreshing. This one is at the San Antonio, Texas. Country Club. Special Features Several important details are merely indicated on the center page illustration. As no pool is complete without a spring board, provisions should be made for one at the deep end of the pool. It may be anchored to the wall of the manhole containing discharge valve, etc., as indicated, or to a separate block of concrete. Spring board details are shown elsewhere. The suggested design shows two ladders, one near the spring board and the other near the corner at the shallow end of the pool. By em- bedding short piping in the top of the waU and floor when the concrete is placed and later fastening the ladder to these, the work of installing the ladder will be made very simple. If desired, ladder rungs may be used embedded directly in the walls, or bolts may be placed to which the rungs are later fastened. Sometimes steps extending across the entire end of the pool are used. If these are built the surface should be left gritty, as by a wooden float, or may be washed with acid. This finish should also be given to the top of the wall to avoid slipping. The safety of the swimmers must also be considered, for which reason a hand-hold should be provided, encircling the pool. Ring bolts should 16 CONCRETE SWIMMING AND WADING POOLS be embedded near the top of the inside wall as indicated. These should be spaced about 10 feet apart and thru them may be run a rope or pipe. If desired, a combination hand-hold and scum gutter may be built in the wall at the time of construction; this is the usual practice for indoor pools. Protecting the Finished Work Important For at least ten days after wall forms have been removed, concrete should be protected from sun and wind by canvas or similar protective covering, in addition to which the covering and the concrete itself should be wet down several times daily. After concreting of the floor is finished, the work must be protected in similar manner as was described for protecting the walls to prevent too rapid drying out of the concrete. Protection should be continued for at least ten days, after which the strip at the outer edge of the floor may be removed and hot tar or asphalt poured into the space between floor and fillet to seal the joint. The Water Supply Overflow and discharge pipes should be provided for as shown; the inlet pipe is not indicated, as its location depends upon local conditions. It is particularly necessary that for inexpensive operation the facilities for filling and emptying the pool be as simple as possible. The pool should be located so that gravity flow will empty it when necessary to change the water for cleaning the pool or for other reasons. Unless the water supply is from a source that furnishes pure clear water, it is desirable to filter the water before passing it into the pool. Sparkling cleanliness of the water contributes much to the enjoyment of bathing in the outdoor pool and to the pleasure of diving. Pool as Skating Rink The coming of cold weather does not mean that the usefulness of the pool has ceased until the next spring. A properly designed and con- structed concrete swimming pool may be allowed to freeze over in winter, thereby providing a skating rink. The circular pool is well adapted to this use, as there is no danger of the ice having any effect on the structure. Materials Required The design which has been described has been made with every regard for economy of materials and equal consideration for efficiency of design. The following estimate will enable one to determine the probable cost as influenced by the price of materials in the particular locality in question: Portland cement 168 barrels Sand 50 cubic yards Pebbles or broken stone 74 cubic yards Reinforcement 3,310 pounds Concrete tile 180 feet of 6-inch If lumber must be purchased solely for this work, about 6,000 feet board measure will be required. If a 4-foot concrete walk is built around the pool this will require 22 barrels of cement, 7 cubic yards of sand and 10 cubic yards of stone. CONCRETE SWIMMING AND WADING POOLS 17 WADING POOLS The Safety of Wading Pools Although many outdoor swimming pools, especially those which are planned with a view to public or semipublic use, are so designed as to include the possibility of being used as a wading pool also, nevertheless the depth of water at the shallow end of such pools is often greater than is safe for small children who cannot swim. Combination snimming and wading poo] in Riverside Park. Toledo, Ohio, combines recreation with safety for all ages. Many public parks have added to their free-for-all enjoyment features a wading pool in which small children can splash at will and race their miniature yachts. A suggested design for such a pool is shown herewith. As planned, the maximum depth of water is uniformly 12 inches. This maximum can be decreased, if desirable, by placing the outlet lower, thus lowering the water level correspondingly. This pool has an over-all diameter of 50 feet. A sloping pavement permits easy entrance to the water. The construction throughout should be of 1 :2 :3 concrete, mixed and otherwise handled as recommended in the construction of the swimming pool described elsewhere. Important Features of Construction As this pool is shallow, the excavation necessary for its location may not extend to sufficiently firm soil upon which to lay the floor, and if so, this area must be compacted by rolling or otherwise, so as to secure a firm foundation for the floor slabs. If the soil is sandy or of a nature that drains readily, no subbase will be necessary. If the soil is not well 18 CONCRETE SWIMMING AND WADING POOLS 5>/ope S^ '. mmsh, 0.^5 lt.pe,r 5f ff. 6 ' Concrete Ti/e ^/rain 6" Concrete Ti'/e ofrain^ ^^_^e' Discharge- p/pa I SECTIOM. U — ^^^^^ + < |- -tSZ" — ^1 Si? — F^l Suggested design for concrete wading pool. drained, the excavation should be made 10 or 12 inches deeper than actually necessary for the floor level, and this space filled with clean, well- compacted gravel containing little sand, or with clean cinders free from ash. This subbase should be well compacted by tamping or rolling Tile drains should first be laid in trenches, as indicated, and provisions also be made for the inlet, discharge and overflow connections. Reinforcing, which in this case is shown as wire fabric weighing at least .35 pound per square foot, should be laid at the center of the 6-inch CONCRETE SWIMMING AND WADING POOLS 19 concrete slabs constituting the floor and the rim of the pool. Details of this work are identical with those followed in one-course sidewalk and pavement construction. A concrete walk 4 feet wide surrounds the entire pool. This walk is 5 niches thick and the same preparation of the foundation should be made for supporting the slabs, which are approximately 5 feet long, as te***"- , ■*■ - ' w» ,^ .. ^ ( Thi.s concrete wading pool at Ellswortb Park. Danville. Hi , furnishes safe pastime for even tile smaller chll Ireii. was recommended for the floor of the pool. Likewise those precautions which were recommended for protecting the concrete of the swimming pool against too rapid drying out should also be taken in this case, the concrete being covered with a protective layer of moist sand or earth — this covering being kept wet for several days. On account of the sloping sides of the pool formed by the slabs that constitute its rim, there is little or no poss bility of the pool be'ng injured by allowing the water to freeze. For this reason the pool will form a safe skating pond in winter for the child en. Below will be found an approximate estimate of the materials necessary to construct a wading pool of the plan and dimensions shown: Portland cement 91 barrels Sand 27 cubic yards Pebbles or broken stone 41 cubic yards Reinforcement 735 lbs. of wire fabric 0.35 lb. persq. ft. Concrete tile 190 feet of 6-inch More complete details of swimming pool design and further information in regard to construction, specifications and recommended practice for swimming pools, wading pools or sidewalks, may be secured by addressing PORTLAND CEMENT ASSOCIATION 111 West Washington Street CHICAGO, ILL. A National Organization To Improve and Extend the Uses of Cement and Concrete I Offers You Its Services ! We know and can tell you how to use concrete so that best results will be obtained. Our various District Offices listed below are service organizations. Get their help in your concrete problems. In addition, you are invited to correspond with our headquarters, in West Washington Street, Chicago, where our HIGHWAYS BUREAU will be J,lad to consult with and advise you on all matters relatinji to the improvement of roads streets and alleys through the medium of concrete. Our STRUCTURAL BUREAU will ^ive you help and cooperation on individual problems involving the use of concrete for railroad work, bridges and culverts, buildings, dams, power houses and other structures. Our CEMENT PRODUCTS BUREAU can advise on the suitability and availability of all structural concrete products, as well as concrete sewer and culvert pipe, drain tile, telegraph and tele- phone poles, li^htin^ standards, etc. These departments are constantly in touch with the ex- tensive researches being made by the Structural Materials Research Laboratory, operated jointly with the Lewis In- stitute, Chicago. Their recommendations are based on the most advanced information obtainable. Educational booklets and pamphlets fully illustrating and describing the important uses of concrete await your request. We are at your service. Consult us freely. Your satisfac tion is our reward. 4 1 PORTLAND CEMENT ASSOC] OFFICES AT Des Moines Parkersburg Detroit Los Ange'.es Philadelphia Helena Milwaukee Pittsburgh Indianapolis Minneapolis Portland, Greg. Kansas City New York Salt Lake City ATTON 1 Atlanta Boston Chicago Dallas Denver San Francisco Seattle St. Louis Vancouver, B. C. Washington, D. C. 3 1924 063 926 392 DATE DUE --a?»< !*M K^sr S H* fJJt >*»w », CAVL.ORD NTED INU > A. .f