I4.6S c.a iiii^LSFACE BRICK f LLl NOl s STATE GE ° LOG ^^VR^ Report °f i^Z ations No. 64 ILLINOIS STATS GEOLOGICAL SURVEY LISRA.Y ■m STATE OF ILLINOIS HENRY HORNER, Governor DEPARTMENT OF REGISTRATION AND EDUCATION JOHN J. HALLIHAN, Director DIVISION OF THE STATE GEOLOGICAL SURVEY M. M. LEIGHTON, Chief URBANA REPORT OF INVESTIGATIONS — NO. 64 TESTS OF FACE BRICK FROM ILLINOIS AND OTHER STATES BY CULLEN W. PARMELEE In cooperation with ihe Department of Ceramic Engineering, University of Illinois PRINTED BV AUTHORITY OF THE STATE OF ILLINOIS URBANA, ILLINOIS 1940 STATE OF ILLINOIS HON. HENRY HORNER, Governor DEPARTMENT OF REGISTRATION AND EDUCATION HON. JOHN J. HALLIHAN, Director BOARD OF NATURAL RESOURCES AND CONSERVATION HON. JOHN J. HALLIHAN. Chairman EDSON S. BASTIN, Ph.D., Geology WILLIAM A. NOYES, Ph.D.. LL.D., Chem. D. D.Sc., Chemistry LOUIS R. HOWSON, C.E.. Engineering WILLIAM TRELEASE, D.Sc, LL.D., Biology HENRY C. COWLES, Ph.D.. D.Sc. Forestry ( Deceased^ ARTHUR CUTTS WILLARD, D.Engr., LL.D.. President of the University of Illinois STATE GEOLOGICAL SURVEY DIVISION i rba na \I. M. LEIGHTON, Ph.D.. Chic! ENID TOWNLEY, M.S., Assistant to the Chiel JANE TITCOMB, M.A.. Geological Assistant GEOLOGICAL RESOURCES Coal G. H. CADY, Ph.D.. Senior Geologist and Head L. C. McCABE, Ph.D.. Associate Geologist FAMES M. SCHOPF; Ph.D., Assistant ('.colonist J. NORMAN PAYNE, Ph.D.. Assistant Geologist CHARLES C. BOLEY, M.S., Assistant Mining Engi- neer Industrial Minerals J. E. LAMAR, B.S.. Geologist and Head H. B. WILLMAN, Ph.D.. Associate Geologist DOUGLAS F. STEVENS, M.E., Research Associate ROBERT M.GROGAN, Ph.D., Assistant Geologist ROBERT R. REYNOLDS, B.S., Research Assistant Oil and Gas A. H. BELL, Ph.D.. Geologist and Head G. V. COHEE, Ph.D.. Assistant Geologist FREDERICK SQUIRES, B.S., Associate Petroleum CHARLES W. CARTER, Ph.D., Assistant Geologist F. C. MacKNIGHT, Ph.D., Assistant Geologist ROY B. RALSTON, B.A., Research Assistant WAYNE F MEENTS, Research Assistant Areal and Engineering Geology GEORGE E. EKBLAW, Ph.D., Geologist and Head HARRY McDERMITH, B.S., Assistant Topographic Engineer RICHARD F. FISHER, B.A.. Research Assistant Subsurface Geolog y L. E. WORKMAN. M.S.. Geologist and Head ELWOOD ATHERTON, Ph.D.. Assistant Geologist MERLYN B. BUHLE, M.S., Assistant Geologist I. T. SCHWADE, M.S.. Assistant Geologist FRANK E. TIPPIK, B.S., Research Assistant Stratigraphy and Paleontology I. MARVIN WELLER, PhD.. Geologist and Head CHALMER L. COOPER. M.S., Associate Geologist Petrography RALPH E. GRIM, Ph.D., Petrographer RICHARDS A. ROWLAND, Ph.D., Assistant Geolo- gist Physics R. I. PIERSOL, Ph.D., Physicist DONALD O. HOLLAND, M.S.. Assistant Physicist PAUL F. ELARDE, B.S., Research Assistant 1ACK TCTTLF, Assistant GEOCHEMISTRY FRANK H. REED, Ph.D., Chiel Chemisl W. F. BRADLEY, Ph.D.. Associate Chemist O. C. FINGER, Ph.D.. Associate Chemist HELEN F. AUSTIN, B.S., Research Assistant Fuels G. R. YOHE, Ph.D., Associate Chemist in Charge CARL HARMAN, B.S., Research Assistant Industrial Minerals J. s. MACHIN, Ph.D.. Chemist and Head JAMES F. VANECEK, M.S., Research Assistant . Inalytical 0. W. REES, Ph.D., Chemist and Head I.. I). McVICKER, B.S., Assistant Chemist GEORGE W. LAND, B.Ed., Research Ass.stant P. W. HENLINE, M.S.. Research Assistant MATHKW KALINOWSKI, M.S., Research Assistant ARNOLD J. YERAGCTH, M.S., Research Assistant MINERAL ECONOMICS W, II. VOSKUIL, Ph.D., Mineral Economist GRACE N. OLIVER, A.B., Assistant in Mineral Eco- nomics EDUCATIONAL EXTENSION DON L. CARROLL. B.S., Associate Geologist PUBLICATIONS AND RECORDS GEORGE E. EKBLAW. Ph.D., Geologic Editor CHALMER L. COOPER, M.S., Geologic Editor DOROTHY E. ROSE, B.S., Technical Editor KATHRYN K. DEDMAN, M.A., Assistant Technical Editor ALMA R. SWEENY, A.B., Technical Hies Clerk FRANCES HARPER LEHDE, M.S., Assistant Tech- nical Files Clerk MEREDITH M. CALKINS. Geologic Draftsman LESLIE D. VAUGHAN, Asst. Photographer DOLORES C. THOMAS, B.A., Geologic Clerk Consultants: Ceramics, CULLEN W. PARMELEE, M.S.. D.Sc. and RALPH K. HURSH, B.S., University of Illinois; Pleistocene Invertebrate Paleontology, FRANK COLLINS BAKER, B.S., University of Illinois. Topographic Mapping in Cooperation with the United States Geological Survey. (A27033— 2M— 7-40) July 1, 1940 CONTENTS Page Abstract 5 Introduction 5 Acknowledgments 5 Samples 5 Face brick and their properties 6 Standard tests and specifications 7 Descriptions of tests and analyses of data 7 Color and surface 7 Uniformity of size and shape 12 Absorption 17 Density 22 Soluble salts 22 Compressive strength 23 Transverse strength 27 Hardness 29 Summary 31 ILLUSTRATIONS Figure Page 1 Classification according to color of brick tested 8 2 Uniformity of size and shape of brick tested 16 3 Absorption values for the brick tested 21 4 Compressive strength values of brick tested 24 5 Transverse strength values of brick tested 28 TABLES Page 1 Manufacturers of Illinois face brick tested 6 2 Color, surface, and other data 9 3 Uniformity of size and shape 13 4 Absorption, soluble salts, and density 18 5 Compressive and transverse strength 25 6 Hardness 30 [3] The illustration of Illinois face brick on the cover is an enlargement from a natural color photograph of the new Natural Resources Building, Urbana, Illinois. TESTS OF FACE BRICK FROM ILLINOIS AND OTHER STATES BY CULLEN W. PARMELEE ABSTRACT Comprehensive standard tests for color, uniformity of size and shape, absorp- tion, density, soluble salts, compressive strength, transverse strength, and hardness, were made on representative lots of samples of face brick manu- factured in Illinois, Indiana, Ohio, and Pennsylvania. The brick from the last three states were selected because they are sold competitively in the Illinois market with Illinois brick. Twenty-four lots of samples were tested from Illinois, fifteen from Indiana, five from Ohio, and six from Pennsylvania. Similar data obtained from other sources are given for nine lots of samples of face brick from Oklahoma and eleven from Virginia, a total of seventy lots of samples. The results of these tests are compared with standard specifications and with each other, and show that face brick produced in Illinois have properties far better than the requirements specified by the Federal Specifications, the Build- ing Code Committee of the U. S. Department of Commerce, the American Society for Testing Materials, and the American Face Brick Association ; and compare favorably with, or are superior to, face brick produced in the other states mentioned. INTRODUCTION Architects, engineers, building supply . dealers, contractors, and other users of face brick in Illinois have requested author- itative information regarding properties and characteristics of face brick manufactured in Illinois and in other states which supply face brick to the Illinois market. This in- vestigation was undertaken to meet this need. Acknowledgments This investigation was made under a cooperative arrangement between the Illi- nois State Geological Survey and the De- partment of Ceramic Engineering of the University of Illinois, with financial assis- tance from the work agencies of the United States Government. The samples were selected under the supervision of Dr. Cameron G. Harman and Mr. Wayne Duvall of the Department of Ceramic Engineering. The Illinois State Geological Survey furnished the major part of the funds for salaries and also the trans- portation for the field party and the samples. Douglas F. Stevens, Research Associate of the Survey, assisted in the preparation of the report. The laboratory equipment and testing machines of the Department of Ceramic Engineering and the Structural Materials Laboratory of the College of Engineering of the University of Illinois were used in making the various tests. Samples Samples typical of all kinds of face brick currently sold in Illinois were selected by a field party, under competent supervision, that visited the plants of most of the face brick manufacturers in Illinois and several [5] ILLINOIS FACE BRICK of those in Indiana. This field party also visited the storage yards of several face brick dealers in Chicago and selected samples of face brick manufactured in Ohio and Penn- sylvania. These were taken from stocks shipped into Illinois for sale and use in this State. Each lot of samples consisted of a definite number of individual brick (100 each for Illinois manufacturers, 30 each for manu- facturers from other states) which were selected with special care to represent a cer- tain kind of first quality face brick regu- larly shipped by the manufacturer. Each lot of samples represented one uniform shade of color, except in some instances where it rep- resented mingled shades, which are marked on the data tables. All of the brick in each lot of samples were tested for uniformity of size and shape. Groups of five brick each, selected to rep- resent the average of each lot of samples, were used separately for each of the various other tests. By this general procedure, a sufficiently large number of brick of each kind was tested to give true values for the properties determined. Tests were made on twenty-four lots of samples of face brick manufactured in Illi- nois by fourteen manufacturers, on fifteen lots from Indiana, i\ve from Ohio, and six from Pennsylvania. The Illinois manufac- turers and the locations of their plants in which the brick tested were produced, are listed in table 1. Table 1. — Manufacturers of Illinois Face Brick Tested Location of plant Manufacturer (Illinois) Albion Brick Co Albion Alton Brick Co Alton Conco-Meier Co. Lowell Ford Brick and Tile Co Harrisburg Hill Brick Co East St. Louis Hydraulic-Press Brick Co Sparland Colchester Brick and Tile Co. . .Colchester Moody Bros Carlinville Poston-Springrield Brick Co Springfield Purington Paving Brick Co Galesburg Purington Paving Brick Co Streator Richards Brick Co.. . Edwardsville St. Elmo Brick and Tile Co St. Elmo Streator Brick Co Streator Western Brick Co Danville The sample lot numbers used in this report have no relation to the order in which the manufacturers are listed in this table. Published data on nine sample lots of face brick from Oklahoma and eleven from Vir- ginia are included in this report for com- parison. The samples were tested by meth- ods similar to those used in this investiga- tion (9, 13). 1 Data on a total of seventy lots of samples from all states are included in this report. FACE BRICK AND THEIR PROPERTIES Face brick are those produced and used to give a particular appearance and character to the surfaces of exterior or interior walls of buildings and other structures. One side and one end of each brick are known as the "face surfaces" of the brick, and may be manufactured with a particular surface and color. Face brick are made from three well known types of raw material : shale, surface clay, and fireclay. They are manufactured by one of the following processes: Stiff mud (extruded through dies and cut into units, using a relatively small amount of water in mixing) Soft mud (formed in molds, usually sanded, with a relatively large amount of water in mixing) Dry press (formed in molds under high pressure, adding very little water to the clay) Face brick made from shale, surface clay, and fireclay have such different physical properties that it is desirable to consider separately brick made from each type of raw material. Users of face brick are interested pri- marily in the ability of this material to give a particular characteristic appearance to the walls, floors, or other structures in which they are placed, and in their capacity to keep this appearance under various condi- tions of use. This depends upon their color, surface, workability when being installed, and their reaction to moisture, weathering, stresses due to load, and other effects from the service in which they are placed. Selection of color and type of surface, whether smooth, semi-smooth, sanded, or rough, is largely determined by individual taste. The workability of brick depends upon their size and uniformity, how they will •Numbers in parentheses refer to bibliography at end nt the report. TESTS AND ANALYSES work with windows, doors, and other struc- tural units, and the rate and amount of moisture they will ahsorh from the mortar with which they are laid. Capacity of face brick to continue to present the appearance and preserve the strength and weather resistance desired, de- pends upon their absorption of moisture and soluble salts from mortar, stone trim, or earth. These soluble salts may cause stains or efflorescence. Resistance to disintegration or spalling from weathering, compressive strength, and transverse strength also are important properties which affect the dura- bility of face brick. STANDARD TESTS AND SPECIFICATIONS Various standard methods of testing these physical properties and standard values for different grades of building brick have been established by the American Society for Testing Materials, the Federal Specifica- tions Division of the U. S. Department of the Treasury, the Building Code Commit- tee of the U. S. Department of Commerce, the American Face Brick Association, and other organizations. These standard methods of testing were applied to each of the sample lots of face brick, and the values obtained were com- pared with the standard specifications estab- lished. Color and type of surface were observed and recorded, and compared with Munsell color charts. Uniformity of size and shape were meas- ured by the Standard Grading Rules of the American Face Brick Association (A.F.B. A.) and were compared with their stand- ards as well as with those of the American Society for Testing Materials (A.S.T.M.) and with the Federal Specifications estab- lished by the Federal Specifications Divi- sion of the U. S. Department of the Treas- ury (Fed. Spec). Absorption and density were tested by standard methods, and the values deter- mined were compared with those of Federal Specifications. The brick were tested for the presence of soluble salts and any evidence of efflor- escence was recorded. Compressive strength was tested by the A.S.T.M. standard method, and the values secured were compared with their specifi- cations and with those of the Building Code Committee of the U. S. Department of Commerce. Transverse strength was tested by the A.S.T.M. standard method, and the values determined were compared with Federal Specifications. Hardness was tested by the Brinell method. DESCRIPTION OF TESTS AM) ANALYSES OF DATA Color and Surface description of tests The color and type of surface of each lot of samples, the number and size of core holes, and other information including de- airing, zinc flashing, and the use of manga- nese were observed and are recorded in table 2. The sample lots were arranged accord- ing to the raw material used and the process of manufacture as follows: Shale face brick — stiff mud process 37 lots Fireclay face brick — stiff mud process 24 lots Surface clay face brick— stiff mud, soft mud and dry press processes 9 lots Total 70 lots The types of surface represented are as follows : Rough surface 40 lots Semi-smooth surface 6 lots Smooth surface 24 lots Total 70 lots The firing of face brick necessarily pro- duces a variety of colors so that no two bricks will have exactly the same color over all of their face surfaces. Special treatment may be given during the firing process by changing the amount of air admitted to the kiln or by adding chemicals to the fuel, so that a wide variety of colors results. The brick are sorted into uniform and mingled shades as they are drawn from the kilns. The standard grading rules of the American Face Brick Association (11) define a uni- form shade as such a selection of face brick that 39 brick laid up as a panel and viewed at a distance of 50 feet appear to have a ILLINOIS FACE BRICK KEY • COLORS OF ILLINOIS FACE BRICK o COLORS OF FACE BRICK FROM OTHER STATES LT LIGHT GR GRAY DK DARK BR BROWN V *y y y REDDISH BR. I ••■■■ REDDISH BR RED LT REDDISH BR O I <>•• DK RED to I •• DK REDDISH BR •• I • LT. RED RED O o« YELLOW- RED (R-YR)HUE _J I I I L A /s A CHROMA A A V J y G RAY • GRA' t TAN LT oo TAN O GR. • BR. BRO • WN T/ o ,N DK.BR o»oo BR( )WN o DK.BR • YEI _LOW - RE C )( YR )HUE A A /$ A CHROMA A A y i i LT. GR BUFF oo 1 LT. BUFF 1 OOO y LT.GR.LT. GR BUFF • 1 1 OO LT. BUFF 1 o»o O y LT.GR • LT.GR BUFF • BUFF • OOOO D ' _l < > y GR. BUFF • DK. BUFF O GR BR GR.BP O* . y DKGR.BR. • y y YE LLOW 1 -RED YELLOW ( i YR-Y ) HUE 1 1 A A A A A A A A CHROMA V ! < I LT.GR LT GREENISH GR Ol 1 OO 1 y LT.GR LT. G REENISH GR. ° 1 V LT • GR • O GREEN SH GR _i GR ^Y LT. GR •O GREEN < > y DK. GR. GR < .REEN • y DK.GF • GREE A y y YEL LOW (Y)Hl JE A A A CHROMA A A Fig. 1. — Classification according to color of brick tested (table 2). These diagrams represent four hue charts of the Munsell color system, on each of which is plotted the hue, value, and chroma readings for the sample lots of face brick tested. Descriptions of the colors have been made by the author. uniform color. Mingled shades are combi- nations of various shades and colors. Classification of colors and shades neces- sarily involves the personal opinion of the observer and frequently differences of opin- ion result. To overcome this, several sys- tems of color classifications have been de- vised. The Munsell color system (8) is being used by architects and manufacturers for recording and identifying the colors of clay products. This system classifies color according to three properties, as follows: Hue — the common name of the color, namely, red (R), red yellow-red (R-YR), yellow-red (YR), yellow-red yellow (YR- Y), yellow (Y). Value — the light strength of the color, namely, dark (1/), middle (5/), light (9/). Chroma — the color strength or intensity, namely, weak (/2), moderate (/5), strong (/10). The complete color description is written thus — Hue, Value/Chroma. Therefore "YR 4/6" represents yellow-red hue, 4th degree or middle light strength, 6th degree or moderate strong color intensity (2). Representative samples of each lot of face brick were matched against the Munsell color charts, and both visual and the Mun- sell descriptions are recorded in table 2 and figure 1. The Munsell chart numbers given represent the average of each uniform shade TESTS AND ANALYSES and the range of variation of each lot of mingled shades. Descriptions of the colors have been made by the author. RESULTS For shale face brick the colors varied from dark brown (YR 3/2), through dark red (R-YR 4/6), to light reddish-brown (R-YR 5/6 and light red (R-YR 4/8). For zinc-flashed shale brick the colors varied from dark gray-green (Y 4/2) to light gray-green (Y 6/4). For fireclay face brick, the colors varied from dark brown (YR 4/2) through light tan (YR 6/6), buff (YR-Y 7/6) to light gray-buff (YR-Y 8/4) and light gray (Y 8/2). For manganese-mix fireclay brick, the colors varied from gray (YR 6/3) to light greenish-gray (Y 8/4). CONCLUSIONS Figure 1 shows that the range of colors available in face brick made in Illinois is quite similar to the range of colors in face brick made in other states. Limitations of this investigation necessarily restricted the sampling to only certain characteristic shades from each manufacturer, but every manufacturer of face brick produces a wide variety of shades in addition to those tested. The selection of the color and surface of face brick most suitable for a certain struc- ture depends a great deal upon individual taste. Table 2 and figure 1 of this report show that face brick made in Illinois offer as wide a variety of choice and as attractive colors and surfaces as can be found in those made in other states. Table 2. — Color, Surface, and Other Data Sample lot no. Surface Shade- Surface color (average) Descriptive Munsell hole No. Size diam, in. Miscellaneous Shale Face Brick — Stiff Mud Process Illinois 1... 2.... 3... 4... 5.... 6... 7.... 8.... 9... 10... 11.... 12. ... 13.... 14... 15... Indiana 16... 17.... Rough Rough Rough Rough Uniform Uniform Uniform Mingled Rough Rough Uniform Uniform Smooth Rough Rough Uniform Uniform Uniform Rough Rough Uniform Mingled Rough Mingled Rough Varied . . Rough Rough Uniform Uniform Semi- smooth Semi- smooth Uniform Mingled Reddish-brown Dark red Dark reddish-brown. Brown to red Dark brown Dark red Light reddish-brown Red Dark reddish-brown Brown Green to gray Brown to red Gray-brown to dark gray-green Reddish-brown Dark brown Light reddish-brown Dark brown to red. . R-YR 4/4 R-YR 4/6 R-YR 3/5 R-YR 3/4, 4/4 to 4/8 YR4/2 R-YR 4/6 R-YR 5/6 R-YR 4/8 R-YR 3/5 YR5/4 Y5/6, 6/4 to 7/2 R-YR 3/6, 4/5 to 5/6 YR 5/2, YR-Y 4/2 to Y 4/2 R-YR 5/4 YR3/2 R-YR 5/5 R-YR 3/2, 3/6 to 4/8.. 2 % 3 % 3 % none 3 % 3 i Vr 2 i 3 % 3 i % 3 i 2 Msq. none 3 1 % 3 % 3 1 3 1 none End holes Center hole De-aired End holes Center hole Zinc-flashed Zinc-flashed, End holes Center hole End holes Center hole 10 ILLINOIS FACE BRICK Table 2. — (Continued) Sample lot no. Surfac Shad( Surface color (average) Descriptive Munsell Core holes No. Size diam in. Miscellaneous 18 19 20 Ohio 21 22 Pennsylvania 23 Semi- smooth Rough Rough Rough Rough Smooth 24 Smooth Oklahoma" 25 Various 26 (not specified) 27 . 28 .. 29 . 30 31 32 33.. Virginia b 34 35.. 36 . 37 Uniform Uniform Mingled Mingled Mingled Uniform Uniform Mingled Uniform Uniform Uniform Uniform Uniform Uniform Mingled Uniform Uniform Uniform Uniform Uniform Reddish-brown Light reddish-brown Dark brown to red. . Green through brown to red Matt surface R-YR 4/4... R-YR 5/6... R-YR 3/2, 3 ; to 4/8 none 3 I 1 Dark brown to light red Dark red Dark red Y 6/4, YR 4/4 to R-YR 4/7 YR 4 2 to R YR 5/4 to 5/8 R-YR 4 5. R-YR 4 6 Green brick zinc- flashed none none Red to flash Dark gray-green. . . Light red Light red Dark red Red Gray-brown Dark brown to red. Red (not deter- mined) . . none none none none 3 none none Red Red Red Dark red Fireclay Face Brick — Stiff Mud Process Illinois 38... 39... 40. 41. 42. 43. 44. Indiana 45 ... . 46. 47. Rough Rough Uniform Uniform Rough Rough Uniform Mingled Rough Uniform Rough Rough Uniform Uniform Rough Mingled Rough Mingled Rough Mingled Light gray Light gray-buff Light buff Gray to light gray. Light gray Gray-brown Buff Dark brown to gold Brown to light buff. Buff to light gray buff YR-Y7/2 YR-Y7/4 YR-Y8/6 YR 6/3, YR-Y 6/4 to Y 7/3 . YR-Y 8/2 YR-Y 5/6 YR-Y 7/5 YR 4/2 to 6/6 to YR-Y 7/6 YR-Y 5/6, 7/6 to 8/6 YR-Y 7/6, 8/4 to 9/4 3 1 3 V?, % 3 V* none 3 1 y* 3 % 14 V.. ib 4J c/> C J2 Q _* 3 03 In ib bb X cd c/: u _£ 3 O Sj 000 000 rt 00 fc ,_l > r- O _c , hC 5 £2 u <£ _c £ <^ K. ^! ^.y »*.-e <* &< C ct c lb — . o , O ^ K. o F J3 ,-n 3 < <— ' IS^ OfoaoNfOTfi'(N sO OC r-i rr- t^ fNrHMfNOf/INMrtfMrHrOrtfNtN c^ r^ O — »-< eN C/3 0, on §rt(NroOiXiaO'-i 4— • C/3 4—> C/3 *_i 4-1 C/ o o.j, o._ O O ' o o o o OOgOc OOc £ £ <~^ cn rO^f MTtf^f ro ■-5 ro CO fO r-. rf fONTt LO LO LO O l^ (NMrtOO ojt-h^- Of^'H'- *- ' a -s? o © 5 "a 5 -) lo rt- on oo o 10 o <"* a •* ro^ta 00 00 ro C O fN tJ< ■rt ■^rt^pc ro rt "C^~ 'c ►5 « rt > — Oh rt • • • • c ; ; ; ; > bfl O (A rt -S .SoO-HfNfOrt OlOON c s O0 On © *H £0 Tj^l^lOl^lT £ LO LO "~ LO LO NO NO c o CL< < -a o Q 10 SHALE FACE BRICK FIRECLAN ACE BRK STANDARDS F j\ FED- SPEC. Vjt\MUL IVI < CL m Anr \ \ < CL o I O ILLINOIS IND-, OHIO IND., Z i J J i i » i i i 1 > i 4 > < 1 » < i • i l : r < • ! i i i » i : » i i to i i i i Fig. 3. — Chart showing absorption values for the brick tested, compared with Federal Specifications standards (table 4). 22 ILLINOIS FACE BRICK Density Architects and engineers are interested in knowing the density of face brick, so that they can calculate the weight of masonry. The terms "bulk density" and "bulk spe- cific gravity" are used in somewhat different ways in various industries. They are em- ployed in this report according to the usage in the clay products industry (10). Bulk density is the weight per unit vol- ume of the brick (i.e. the volume including all the pores). Bulk specific gravity is the ratio between the weight of the brick in air and the weight of an equal volume of distilled water at a stated temperature. Thus, if a brick weighs in air 2.22 grams per cubic centimeter, its bulk density is 2.22 grams per cubic centimeter. Since water weighs 1 g. per cc. (correct to 0.3 per cent at room temperature, i.e. 70° F. ), the bulk specific gravity of this brick is 2.22. Water weighs 62.4 pounds per cubic foot (distilled water at room temperature, 70° F.)j so the bulk densitv of the brick is 2.22 X 62.4= 139 lbs. per cu. ft. DESCRIPTION OF TESTS The bulk density and the bulk specific gravity for each lot of samples were deter- mined by taking the five brick tested for absorption immediately after their saturated weight was obtained, and weighing each separately as it was suspended in distilled water at room temperature. This gave their suspended weights. The difference between saturated and suspended weights is the weight of a volume of water equal to the exterior volume of the brick. The bulk density was then calculated by the formula, which has recently been issued by the A.S.T.M. (6): Bulk density Dry weight of brick (g.) (g. per cc. ) = ; Saturated weight (g.) — Suspended weight (g. ) Dry weight of brick (g.) Weight of water of equal volume to that of brick (g.) Dry weight of brick (g). Exterior volume of brick (cc. ) This value multiplied by 62.4 (weight in pounds of 1 cu. ft. of water) gives the bulk density in pounds per cubic foot. Both sets of values are given in table 4. Bulk specific gravity is calculated by the following formula (10): Bulk specific Dry weight of brick (g.) gravity = ; Weight of water of equal vol- ume to that of brick (g.) Therefore the numerical values for bulk density in grams per cubic centimeter are also the values for bulk specific gravity of the various samples tested. RESULTS AND CONCLUSIONS The average bulk density of the five brick selected as representative of each lot of samples tested is given in table 4, both in grams per cubic centimeter and in pounds per cubic foot. These values averaged about 2.20 g. per cc. for Illinois face brick tested and about 2.17 g. per cc. for brick from other states, which shows that the range of density is approximately the same for all brick tested. Soluble Salts description of tests When face brick which contain more than slight amounts of soluble salts absorb water, they may show efflorescence after they are dried out. Relative amounts of soluble salts were determined by selecting iive representative brick from each lot of samples which were placed in distilled water at room temperature (70° F.) so that half of the volume of each brick was immersed and the face surface exposed to the air. The level of the water was maintained until the brick were thoroughly saturated, and the water was then allowed to evaporate completely. The face surface of each brick was examined for the appearance of soluble salts as efflorescence. The amount was re- corded according to the classification recom- mended bv the National Bureau of Stand- ards (5)." RESULTS AND CONCLUSIONS Table 4 records the extent of efflorescence caused by soluble salts contained in each of the samples tested. For face brick made in Illinois, out of 24 lots examined, 12 showed no efflorescence, 2 showed "trace" and 6 showed "slight." That is, 83 per cent of the Illinois brick TESTS AND ANALYSES 23 would not be likely to show efflorescence in ordinary use according to the investigation referred to (5). For those tested from Indiana, Ohio, and Pennsylvania, out of 26 lots examined, 10 showed no efflorescence, 1 showed "trace" and 12 showed "slight," or 88 per cent would be unlikely to show efflorescence. Hence the Illinois face brick tested are substantially as free from soluble salts as those tested from other states. It is well known that most of the efflor- escence that appears on brick walls does not come from the face brick, but comes from the mortar, from stone trim or back-up material, from contact with earth, from moisture entering the walls from faulty drains, or from the top or back of the wall being exposed to moisture. Therefore, the possible effect of soluble salts from these sources should be prevented by stopping circulation of moisture in the walls by waterproofing brick walls, founda- tions and stone trim, and by insuring that all mortar joints are tight and that the top and back of exposed or "parapet" walls are waterproofed. Compressive Strength Face brick are subjected to compressive stress in carrying the load placed on masonry walls. It is therefore of great importance to determine the compressive strength, or Compressive strength (lbs. per sq. in.) maximum compressive stress which the brick can stand, measured at failure, in load per unit of original cross-sectional area of the brick. DESCRIPTION OF TESTS Five representative brick were selected from each lot of samples and each of these five brick was subjected to compressive stress in accordance with the established standard tests of the American Society for Testing Materials (12). The selected bricks were thoroughly dried at a temperature of 212°-220° F., and were cut in half perpendicular to their length by an abrasive cut-off wheel. One-half of each of these bricks was taken as the test specimen. Two opposite flatwise sides of each specimen were coated with shellac and then with plaster of Paris to produce two opposite smooth parallel surfaces. The areas of these surfaces were measured, and each specimen was tested lying flat in a standard vertical testing machine. The load was applied in the direction of the thickness of the brick under standard conditions until the brick crushed, and the maximum load at failure was determined. Precautions were carefully observed relative to the use of spherical bearing blocks, speed of applica- tion of the load, etc. Compressive strength was then calculated for each specimen by the formula : indicated by testing machine at failure of specimen (lbs.) Average of areas of upper and lower bearing surfaces of specimen (sq. in.) M; load RESULTS Table 5 records the average compressive strength for the five brick tested from each lot of samples, and also the maximum and minimum strength shown by the individual brick in each set of five samples tested. The data are grouped according to the raw ma- terial from which the brick were made. These results are compared with the standards established by the American Socie- ty for Testing Materials (1), and the Building Code Committee of the U. S. De- partment of Commerce (7). All face brick tested from Illinois had compressive strength which exceeded by 5,000 to 11,000 lbs. per sq. in. the A.S.T.M. standard of 2.500 lbs. per sq. in. (fig. 4). Every sample lot, with one excep- tion, had compressive strength equal to or above the Grade A classification of the U. S. Dept. of Commerce Building Code Com- mittee, which is 8,000 lbs. per sq. in., and some of the sample lots had strength more than 5,000 lbs. per sq. in. above this high standard. Most of the face brick tested from other states had compressive strength in excess of the A.S.T.M. standard, and many of them had strengths above the Building Code Committee's highest stand- ards. These results are presented graphi- cally in figure 4. 24 ILLINOIS FACE BRICK SHALE FACE BRICK FIRECLAY SURFACE — - FACE B CLAY 18,000 -FACE BRICK- n\c k 4 1 T 16,000 i • ii < • 14,000 < » J i 1 » » > < 4 t i 12,000 * i _i *: o > < I 4 , 1 i 4 : 4 p i i i STANDARDS 10,000 i I 4 > j 1 1 < BUILDING :ode COM. A.S.T.M. < • i 1 » 1 j c 8,000 i 1 1 1 i i 3 c > « r < Ql i 4 4 4 t 1 1 i <> < c ■ OKAUL A — i 6,000 c ( ( D ( z J c j : 2 n 3 4 > C 1 c 5 5 i — c J c J : 5 E OIS i ^ z 4 i : 5 i 7 ILLIls 4,500 4,000 4 ? GRADE b- 2,500 2,000 1,500 1 1 1 CRADF C GRADESW ^ « GRADE MW -GRADE D— GRADE NW » 4 n Fig. 4. — Chart showing compressive strength values of brick tested, compared with A.S.T.M. and Building Code Committee standards (table 5). TESTS AXD ANALYSES 25 Table 5. — Compressive and Transverse Strength Sample lot no. Compressive Strength (lbs. per sq. in. i Modulus of Rupture (lbs. per sq. in.) Aver, of , , A/t 5 brick ! lnd Max - lnd. Min. Aver, of 5 brick lnd. Max. lnd. Min. Standards: Fed. Spec. Grade H (Hard) . . 600 or more. 400 Grade M (Medium) . . 450-600 300 Grade S (Soft) 300-450 200 A.S.T.M. Grade SW a 2500 or more. 2500 or more. 1500-2500. . . 2,500 2,500 1 , 250 400 Grade MW b . 450-600 .... 300 Grade NW c 300-450 . . 200 Bldg. Code Comm. Dept. Commerce A B C D 8,000 or over 4,500-8,000 2,500-4,500 1,500-2,500 Shale face brick — Stiff mud process Illinois 1.... 2.... 3.... 4.... 5.... 6... 7.... 8.... 9... 10... 11... . 12.... 13... . 14.... 15.... Average. Indiana 16... 17. ... 18... 19... . 20... Ohio 21. 22. Pennsylvania 23.. 24 Average (lnd., Ohio, Pa.; 17,794 11,292 13,588 11,846 11,033 13,630 12,718 9,426 13,022 7,951 11,686 8,433 10,810 11,714 13,146 11,873 11,300 16,500 16,500 16,000 17,600 13,000 9,850 15,800 13.600 14,461 20,940 12,042 14,372 12,417 13,041 14,058 13,794 10,969 13,814 9,588 13,233 10,136 11,746 13,069 13,950 13,145 12,500 19,000 17,600 17,600 20.000 14,600 14.000 18.300 14.800 16.489 15,620 10,862 12,659 11,178 9,102 13,136 10.979 8,269 1 1 , 809 6,232 9,815 6,889 10,065 9,458 12,259 10,555 10,700 13,200 14,400 14,000 15.800 9.300 8,200 14,600 12.700 12.544 2,321 524 707 734 1,364 785 848 2,245 1,929 1,456 2,034 1,678 1,770 1,363 1,630 1.759 1,430 2,140 2,160 2,070 2.150 1.670 1,560 2,470 3.140 2,088 2,692 2,005 1,638 1,295 1,981 1,495 2,060 1,414 1,558 1,173 2,182 1,463 2,005 1,502 2,728 1,973 2,008 1,789 1,848 1,223 2,311 1,623 1,912 1,538 1,895 1,726 1,472 1,305 1.896 1,406 2.012 1,529 1.600 7 670 1,250 1 710 2.360 2.280 2,980 2,600 2,000 2,760 3,340 2 , 504 1,780 1,770 1,890 960 1,140 2,230 2,780 1,723 aGrade S\V (severe weathering) — Brick intended lor use where exposed to temperature below freezing, in presence of moisture. b Grade MW (moderate weathering) — Brick intended for use where exposed to temperature below freezing, but unlikely to be saturated with water. e Grade NW (no weathering) — Brick intended for use as back-up or interior masonry. 26 ILLINOIS FACE BRICK Table 5. — (Continued) Compressive Strength Modulus of Rupture (lbs. per sq. in.) (lbs. per sq. in.) Sample lot no. Aver, of 5 brick Ind. Max. Ind. Min. Aver, of 5 brick Ind. Max. Ind. Min. Oklahoma' 1 25 11,402 12,195 9,672 1,522 2,163 976 26 7,224 8,202 6,469 981 1,281 589 27 8,988 14,480 5,021 1,152 1,480 661 28 7,976 9,851 6,593 1,404 1,921 588 29 10,347 12,505 8,463 1,420 1,642 1,028 30 7,546 9,835 4,021 1,328 1,722 1,022 31 6,815 9,511 5.024 811 1.134 648 32 9,304 11.137 7,663 1.402 2,100 777 33 5,715 6,875 4,299 982 1,467 667 Virginia'' 34 7,442 3,951 2,616 9,575 5,386 3,081 6.000 2.310 2,181 1.477 1,303 729 1 , 765 1,503 823 1,245 35 1,064 36 548 37 2.493 2.880 1,725 1,396 1,792 1,230 Average (Okla., Va.J. . 7.063 8,886 5.342 1.224 1,599 849 Fireclay face brick — Stiff mud process Illinois 38 39 40 41 42 43 44 13,333 10,070 9,019 11,422 11,536 7,846 10,920 10,592 15,000 11,400 12,500 12,500 10,500 1 1 , 200 13,500 8,000 8,630 10,400 11,600 7,650 14,500 1 1 , 750 16,200 12,700 12,500 11,796 13,898 11,400 10.432 12.652 12,367 9.042 12,250 11,720 19,200 14.440 17,500 14,300 11,800 12,700 14,800 8,700 10,300 11.800 13,800 8,850 16,600 13,400 18,300 14,300 14,400 13,835 12,973 9,012 7 , 595 9,906 10.301 6,915 9,782 9,498 10.300 9.300 8.000 10,800 10,000 8,500 12,600 7,500 7,580 8,700 10,000 6,300 9,000 7,000 13,400 11,200 9,600 9,399 1,546 1,391 1.585 2.861 1,671 1.136 1.542 1,676 1,210 1,610 1.500 1.630 1.500 1,620 2,050 982 1,720 660 1,600 1,000 1,780 1,370 2,030 2 , 100 2,000 1,551 1,665 1,701 1,856 3,148 1,839 1,167 1,640 1,859 1,540 1,930 1,840 2,200 1,590 1,780 2,200 1,020 1,860 823 1,780 1,440 2,330 1,550 2,150 2,280 2,080 1,788 1,434 1,072 1,330 2,316 1,527 1,092 1,385 Average 1,451 Indiana 45 958 46 1,440 47.. 1,360 48 1,030 49 50 51 1,320 1,430 1,740 52 946 53 1,570 54 Ohio 55 419 1,400 56 860 57 1,120 Pennsylvania 58..' 59 1,225 1,850 60 1,940 61 Average (Ind., Ohio, Pa.) 1,960 1,328 dSheerar, op. cit., p. 10. e Whittemore and Dear. op. cit., pp. 27-32. TESTS AND ANALYSES 27 (Concluded) Sample lot no. Compressive Strength (lbs. per sq. in.) Aver, of 5 brick Ind. Max. Ind. Min. Modulus of Rupture (lbs. per sq. in.) Aver, of 5 brick Ind. Max. Ind. Min. Surface clay j ace brick — Various processes Illinois 62 (Dry press) 9,439 9,797 9,168 1.072 1,220 964 63 (Soft mud) 10,110 11.941 6.422 2.122 2.410 1,793 Average 9,775 10,869 7 . 795 1,597 1,815 1.379 Virginia e 64 (Stiff mud) 6,194 6,714 5,642 1,084 1,234 987 65 (Stiff mud) 4,668 5,672 2,617 847 909 722 66 (Stiff mud) 7 , 755 8,652 6,348 1.013 1.138 913 67 (Stiff mud) 4,667 5 , 703 3,592 1.002 1,461 700 68 (Soft mud) 1,200 1,405 920 585 704 437 69 (Soft mud) 2,917 3,4-14 2.575 830 1,147 481 70 (Soft mud) . 2,435 3,380 1,910 805 934 682 Average 4,262 4.996 3,372 881 1,075 703 e Whittemore and Dear, op. cit., pp. 27-32. CONCLUSIONS The results of tests of all types of Illinois face brick show that these brick possess compressive strength equal to or greater than the highest specifications of the U. S. Department of Commerce Building Code Committee, and that they greatly exceed the highest specifications of the American Society for Testing Materials. The data show that Illinois face brick compare very favorably in compressive strength with brick tested from other states. As the standard specifications have been determined to pro- vide a reasonable factor of safety for any probable load, and as the results of this in- vestigation show that Illinois face brick test far above these specifications, it is evident that they possess much greater strength than is required by any possible structural load. Transverse Strength In masonry walls, face brick are sub- jected to flexure or bending stresses. The ability of a brick to stand these stresses is indicated by its transverse strength, which is measured as the modulus of rupture, or the transverse load per unit of original cross-sectional area of the brick at time of failure. description of tests Five representative bricks were selected from each lot of samples, and each of these five bricks was subjected to transverse stress or flexure, in accordance with the established standard tests of the American Society for Testing Materials (12). The selected bricks were thoroughly dried at a temperature of 212°-220°F., and the width and depth of each was measured. Each whole brick was tested flatwise in a standard testing machine. The brick was supported on steel knife edges set with span of 7 inches, and the load was applied at mid- span, perpendicular to the upper surface of the specimen and in the direction of the thickness of the brick. Standard conditions were carefully observed relative to the knife edges, bearing plate, speed of application of the load, etc. The maximum load at time of failure was determined. The transverse strength or modulus of rupture was then calculated for each brick b\ the formula : Modulus of rupture (lbs. per sq. in.) where W = maximum load 3W1 2bd- maximum load indicated by testing machine at failure of brick (lbs.) 28 ILLINOIS FACE BRICK 3200 O if) CC 2800 LU a. CO o z D g2400 i O tO 2000 600 1200 O 800 600 4 50 400 300 Fig. 5 SHALE FACE BRICK F FA RECLAY SURFACE CLAY ICK CE BRICK — FACE BR i i i i i ( i c 5 c : 7 i i i c i i < > i i 1 ' i » i i i < > << I ; : • 1 o > 1 1 | ( i i < 1 4 i l i ! 1, 1 : • < Z \ 1 « ; i 1 o It > < Q. i ( i 1 ► t C i 5 T J 5 c c - \ l [ o z | I STANDARDS FED SPEC = 5 ► _j i _l _J » • ■ ■ OHMUL IVI m a nr c , -Chart showing transverse strength values of brick tested compared with Federal Specifications standards (table 5). TESTS AND ANALYSES 29 1 = distance between knife edge supports = 7 in. b = average over-all width of brick (in.) d = average over-all depth of brick (in.) RESULTS Table 5 records the average transverse strength or modulus of rupture for the five brick tested from each lot of samples, and also the maximum and minimum transverse strength shown by the individual brick in each set of five samples tested. The data are grouped according to the raw material from which the brick were made. These results are compared with the standards established by the Federal Speci- fications Division of the U. S. Department of the Treasury (3). The same standards were formerly adopted by the American Society for Testing Materials, but the transverse strength tests were omitted in their recent revision (1). All face brick tested from Illinois had transverse strength which exceeded, by 450 to 1700 lbs. per sq. in., the Federal Specifi- cations standard of 600 lbs. per sq. in. All of the face brick tested from other states, except one lot, also had transverse strength in excess of the Federal Specifications stand- ards. The results are presented graphically in figure 5. CONCLUSIONS The results of tests of all types of Illinois face brick show that these brick possess transverse strength which greatly exceeds the highest Federal Specifications, and that they compare very favorably with brick test- ed from other states. As these specifications have been determined to provide a reason- able factor of safety over and above any probable load, and as this investigation shows that Illinois face brick test far above these specifications, it is evident that they possess much greater transverse strength than is required by any possible structural load. Hardness Although face brick are often referred to as "hard burned," there has never been any exact method for determining hardness. The National Bureau of Standards and other testing laboratories have experimented with the Brinell hardness test to determine hard- ness of building brick and its relation to transverse and compressive strength (4). This test was developed for use on metals and other materials having homogeneous surfaces. Although the fact that face brick do not have this type of surface made the successful use of this test questionable, it was applied to some of the lots of samples in this investigation to determine whether it would give useful results. description of tests Five individual brick were selected as representative of each lot of samples from Illinois, Ohio, and Pennsylvania. A small portion of the face surface of each brick was ground smooth on a revolving steel disc fed with 200-mesh carborundum. Each of these brick was tested in a Brinell testing machine. This consists of a hardened steel ball of standard diameter (17.5 mm. = 11/16 in.) which was pressed against the ground surface of the test specimen with a constant standard load (500 kilograms = approximately 1100 lbs.) for a standard length of time (1 min.). A sheet of car- bon paper was placed between the steel ball and the surface of the specimen, and the diameter of indentation of the surface, shown by the carbon on the specimen, was measured. The Brinell Number, or index of hard- ness, is the stress per unit of spherical area of the indentation made in the surface of the specimen by the steel ball, measured in kilo- grams per square millimeter. It was calcu- lated by the following formula : Brinell Number \Y 2-r V where W = constant standard load = 500 kilograms (approximately 1100 lb.) applied for stand- ard time (1 min.). r = radius of standard steel ball = 8.75 millimeters (=11/32 in.) D — Diameter of indentation (mm.) 30 ILLINOIS FACE BRICK Table 6. — Hardness Sample lot no. Rrinell Number (kg. per sq. mm.) Average of 5 brick Maxi- mum Mini- mum Sample lot no. Brinell Number (kg. per sq. mm.) Average of 5 brick Maxi- mum Mini- mum Miscellaneous Shale face brick — Stiff mud process Illinois 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ohio 21 22 Pennsylvania 23 24 99.0 84.0 97 156.9 101.1 173.6 112.3 125.1 112.4 81 .1 115.0 71.5 62.1 72.8 97.9 98 . 5 140.0 155.0 163.0 106.8 106.8 129.2 159.1 121.0 200.0 129.2 129.2 121.0 100.6 129.2 72.4 84.8 106.8 106.8 113 176.0 199 () 193.0 80 43 62 148 76 148 89.8 121.0 100.6 62.4 106.8 68.8 51.8 65.6 68.8 79.5 113.0 133.0 141.0 Fireclay face brick — Stiff mud process Illinois 38 39 40 41 42 43 44 Ohio 55 56 57 Pennsylvania 58 . .' 59 60 61 89.1 106.8 62.4 100.5 106.8 95.0 59.7 76.2 40.2 129.6 138.2 113.6 97.7 113.6 89.8 68.0 68.8 65.6 125.8 148.1 106.8 73.5 109.0 55.0 37.2 51.4 28.0 101.0 155.0 56.0 67 5 83.7 40.8 144.0 167.0 110.0 193.0 193.0 193 148.0 200.0 140.0 Surface clay face brick Illinois 62... 63 34.8 37.2 31.8 80 9 113.6 43.6 Dry press proc- ess Soft mud proc- ess RESULTS AND CONCLUSIONS Brinell Numbers are recorded in table 6 for the average, maximum, and minimum values for the samples tested from each lot of samples from Illinois, Ohio, and Penn- sylvania. The average values for the five brick from each lot varied from 34.8 to 193, while the lowest individual minimum was 28 and the highest individual maximum was 200. Careful study of these results failed to show any consistent relationship between the Brinell numbers and hardness and com- pressive and transverse strengths of the samples tested. Brick do not have homog- eneous surfaces similar to those character- istic of metals. This condition and the difficulty in determining the area of indenta- tion, account for the wide variations in the Brinell numbers and the lack of relation- ship between them and strength determina- tions. Therefore it is believed that the Brinell test for hardness, although possibly of value for testing certain kinds of ceramic products which possess homogeneous surfaces, is not suitable for use with face brick, and that the results obtained do not have value in determining their properties. The data pre- sented here, even though negative, are given as a contribution to the general fund of information regarding the suitability of the Brinell test in determining the hardness of brick. SUMMARY 31 SUMMARY The properties and characteristics of face brick manufactured in Illinois and those made in Indiana, Ohio, and Pennsylvania were investigated, and the results, together with data published on similar tests made on brick from Oklahoma and Virginia, were compared with established standards. Representative sample lots of face brick were selected, twenty-four from Illinois, fifteen from Indiana, five from Ohio, and six from Pennsylvania. The brick from these states were selected because they are sold competitively in the Illinois market. The data also included test data for nine sample lots from Oklahoma and eleven from Virginia. The samples consisted of thirty- seven lots of shale face brick, twenty-four fireclay, and nine surface clay — seventy lots in all, and included brick with rough, semi- smooth, and smooth surfaces. These lots of samples were subjected to comprehensive standard tests for color, uni- formity of size and shape, absorption, densi- ty, soluble salts, compressive strength, trans- verse strength, and hardness. The results of these tests were compared with the stand- ard specifications established by the Ameri- can Face Brick Association, the American Society for Testing Materials, the Federal Specifications Division of the U. S. Depart- ment of the Treasury, and the Building Code Committee of the U. S. Department of Commerce. The range of colors found in Illinois face brick is quite similar to that of the brick examined from other states. Illinois face brick conform to the standards of the Ameri- can Face Brick Association for uniformity of size and shape in 95 per cent of the measurements, while the face brick tested from Indiana, Ohio, and Pennsylvania con- form in 87 per cent of the measurements. Illinois face brick studied have total ab- sorption only one-third the limit specified for the best grade of brick under Federal Specifications, whereas those tested from Indiana, Ohio, and Pennsylvania have total absorption about one-half these specifica- tions. The range of bulk density is approxi- mately the same for all the brick tested, and they all show about the same range of free- dom from soluble salts. In compressive strength, Illinois face brick tested far above the highest require- ments of the American Society for Testing Materials, and above the much higher speci- fications of the U. S. Department of Com- merce Building Code Committee. The face brick tested from Indiana, Ohio and Penn- sylvania, and reported from Oklahoma and Virginia, have compressive strength well above the A.S.T.M. standards, and many lots tested above the Building Code Com- mittee's highest specifications. In transverse strength, Illinois face brick tested far above the highest standards of the Federal Speci- fications. Most of the face brick tested from other states also possess transverse strength well above these specifications. The Brinell hardness test was tried, but was found unsuitable for use with face brick. The comparison of the results of these tests with the various standard specifications show that face brick produced in Illinois have properties far better than these stand- ards, and compare favorably with, or are superior to, face brick produced in the other states whose brick were included in this investigation. 32 ILLINOIS FACE BRICK BIBLIOGRAPHY A.S.T.M. Specifications for Building Brick (Made from Clay or Shale)— A.S.T.M.- C62-39T. Issued by American Society for Testing Materials, Philadelphia, Pa., A.S.T.M. Standards, Part II, p. 916 (1939). Cooper, F. G., Munsell Manual of Color: Munsell Color Co., Inc., Baltimore, Md., 33 pp., (1929). Federal Specification for Brick; Building (Common) Clay — SS-B-656. Prepared by Federal Specifications Division of the U. S. Department of the Treasury, ap- proved June 28, 1932. McBurney, J. W., Relation of Brinell Hard- ness and Transverse Strength to Com- pressive Strength of Building Brick: Journal of American Ceramic Society, Vol. 13, p. 823, 8 pp. (1930). McBurney, John W., and Parsons, Douglas E., Wick Test for Efflorescence of Build- ing Brick: National Bureau of Standards, Research Paper No. 1015, 4 pp. (Julv 1937). Methods of Test for Apparent Porosity. Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Products — A.S.T.M.: C20- 39T. Issued by American Society for Testing Materials, Philadelphia, Pa., A.S.T.M. Standards, Part II, p. 963 (1939). Modifications in Recommended Minimum Requirements for Masonry Wall Con- struction, Report of Building Code Com- mittee of U. S. Department of Commerce (Issued 1924, revisions of 1931 and 1939.) 8. Munsell, A. E. O., Munsell Book of Color: Munsell Color Co., Inc., Baltimore, Md., Abridged Edit., 28 pp. (1929). 9. Sheerar, Leonard F., Physical Properties of Common and Face Brick Manufactured in Oklahoma: Oklahoma Agricultural and Mechanical College, Engineering Experi- ment Station Publication No. 8, 11 pp. (1931). 10. Standard Definitions of Terms Relating to Specific Gravity — A.S.T.M.: E12-27. Adopted 1927 by American Society for Testing Materials, Philadelphia, Pa., A.S.T.M. Standards, Part II, p. 874 (1939). 11. Standard Grading Rules for Face Brick, adopted by American Face Brick Associ- ation, approved by Face Brick Dealers' Association of America and the Joint Trade Relations Committee of the Face Brick Industry. Published by the Ameri- can Face Brick Assn., Chicago, 111. 29 pp. (1931). 12. Standard Methods of Sampling and Test- ing Brick — Compressive Strength and Modulus of Rupture— A.S.T.M.: C67-39. Adopted 1931, Revised 1939, by Ameri- can Society for Testing Materials, Phila- delphia, Pa., A.S.T.M. Standards, Part II, p. 104 (1939). 13. Whittemore, John W., and Dear, Paul S., Physical Properties of Common and Face Brick Manufactured in Virginia: Virginia Polytechnic Institute, Engineering Exper- iment Station Bulletin No. 6, 40 pp., (1930). ILLINOIS STATE GEOLOGICAL SURVEY Report of Investigations No. 64, 1940