‘CONCRETE » “SILOS A Booklet of Practical Information Prepared es- pecially for the Farmer and Rural Contractor. HHH HY EIT TS Silo and Dairy Barn Arcady Dairy Farm ste reeste ees UNIVERSAL PORTLAND CEMENT CO, 6; “CHICAGO ———- PITTSBURG * “ii ‘ear tau s eg oy 0 pans MeavTAeT sac eiviw. ' Tgiuiteds TORRES Peghacea Pye Rie ae CA) Copyright, 1911 nf by : UNIVERSAL PORTLAND CEMENT Co. ~* Chicago — Pittsburg 8-14-11-10 M. CONCRETE SILOS A BOOKLET OF PRACTICAL INFORMATION FOR THE FARMER AND THE RURAL CONTRACTOR Prepared by the INFORMATION BUREAU UNIVERSAL PORTLAND CEMENT CO. if Published by UNIVERSAL PORTLAND CEMENT CO. CHICAGO — PIPPSBURG First Edition 1911 TABLE OF CONTENTS, SILOS AND SILAGE Definitions’ oi 55./. £2 RSG Re a Se ST eg ceo The Theory of Silage. Silage (Crops .. 0.5 cise ob 80 a oie Wilore etelep ce hiche Ainge alae tec The Advantages of Silage. Dry Matter and Digestible Nutrients in Silage!.. 270... 2. ss ee ee Effect of Silage on the Flavor of Milk. Effect on Cattle of a Silage Ration... 2222.95. yon a ee nee eee CAPACITY, DIMENSIONS, AND LOCATION OF THE SILO Capacity for a Given Number of Cattle (Example).-~....-. 7.72. o epee Table of Capacities of Round Silos in Tons. Economical Diameter ©. 0.0.6.6 ssco0,s 0.0.0 elie Seeteteione ae teeter ee eee Height. Wocationy 2 eos ee ke ie ee Oe ne sb atseb ives bane o ska FILLING THE SILO—USING OFF SILAGE Wien ‘to: Harvest! s... <0 04.0.2 oe bee bak DOME ee ee ee ene ee Harvesting the Crop. The (Carter 2 o.6 cos 5 sesccie © siejessnalota te, duausuet sy eaieyeeieaer a ae o ene le re Rete neon Ce eo Elevating and Distributing. ‘ Economy of Filling the Silo Rapidly....2 2.2. ..5..- 2.0. soe eee eee Wetting the Silage. Gost of Filling 2.0524. 320 ..0i0 ESE A ae eee Table Showing the Cost of Filling Fifty-nine Concrete Silos. Gost: ‘of Silage’. 5... sills so Saisad Sec eee Using Off the Silage. ADVANTAGES OF CONCRETE AS A SILO MATERIAL Fireproof ‘Construction (}...4. 0 ..cule Se aise ate ee aire een George Pulling’s Silo. A. BevMain’s. Silo i wg oc ils cco eae tee ee The Element of Waste. The ‘Effect of Freezing 2.0... 2.0. ine eee ee ee eee Concrete Silos in the South. WHAT IT COSTS TO BUILD A CONCRETE SILO Table showing the Cost of 78 Monolithic and 30 Block Silos............... Time Required to Construct Concrete Silos. A Comparison of the Monolithic ané z “I might say that our experience here indicates that there is no difficulty in putting up the ordinary type of silo in this state by reason of the cold weather which occurs during the winter season. Our farmers who have had experience with them recommend building them outside of the barn rather than to put them inside to protect them from heavy freezing of the ensilage on the walls. I think there will be a large increase in the number of silos in this state in the next few years.” Silo Failures LTHOUGH failures of concrete silos are extremely rare, the A few cases which have arisen have been given wide publicity as proof that concrete is not a suitable material for this class of work. Almost without exception, the failures which have occurred have been due to insufficient reinforcing, a cause which affects silos of other materials to as great an extent. One or two cases have been seen where poor materials have contributed to the failure, and in one instance cracks occurred between the courses of a monolithic silo due to poor bond at points where concreting was dis- continued. This condition might have been prevented by the treat- 28 CONCRETE SILOS ment described on page 54. The use of dirty, poorly proportioned, weak aggregates, mixed without sufficient water or cement, will not give satisfaction, and the sooner discontinued, the better. .There is no reason for a single failure, if sufficient reinforcing is properly put in, materials are clean and well proportioned, and the work done in accordance with the directions laid down in the following pages. - The silo shown in Figure 18 is especially interesting, because it has been widely used by manufactu- rers of other types of silos, as a strong ex- ampie of concrete silo failure. So far as can be learned, however, none of these parties have ever tried to ascertain the true reason for the failure, which might have been made perfectly clear by a short in- vestigation. Bulletin No. 100 by the Iowa . ' , State Agricultural Fig. 18. Large monolithic concrete silo, built for the Waukesha a : Canning Company, Waukesha, Wisconsin. One of the largest College = ae 3 silos in the world. Capacity, 2,250 tons; cost, $2,500. Filled with There is an excess pea vines, producing silage as a bi-product of the cannery. of juice in pea vines and in order to pre- vent an accumulation of this and a consequent excessive internal press- ure, a large drain was placed at the center of the silo. This drain for the first two years accomplished its purpose, but upon the third filling it became clogged, allowing the juices to accumulate to a depth of at least 20 feet. By caiculation it was determined that the bursting pressure in the silo due to the 20 feet of juice was more than double the strength of the steel reinforcement in the wall forthe bottom 18 inches. ‘This shows conclusively that the concrete was not at fault and this instance cannot be used as an argument against the concrete silo. If the silo is filled with corn, that is properly matured, the above conditions cannot occur.’’ The above only partly explains the difficulty. An investigation shows that the walls were reinforced by five-eighths-inch rods, spaced eighteen inches apart at the bottom, increasing to three feet at the top, which is not enough to properly reinforce a silo twenty feet in diameter. This silo has a diameter of sixty feet, a height of forty feet, and a capacity of 2,250 tons, about eight times as great as that of a silo of the same height, twenty feet in diameter. Concrete Silos in the South _ Alarge number of monolithic, concrete block and cement plaster silos have been put up throughout the South, many excellent: examples UNIVERSAL PORTLAND CEMENT CO. 29 being reported in the states of Maryland, Virginia, North and South Carolina, Georgia, Alabama and Mississippi. Without exception these silosare giving splendid satisfaction, and it is only becanse of the lack of time in preparing the present book- let that the methods of constructing silos in the southern states are not fully discussed. Cement plaster silos built by ap- plying a coat of stucco to a metal frame is a type peculiar to this sec- tion and has been recommended by one or two of the Southern Agricul- tural Schools. L; The following extract from a let- ter from Prof. J. A. Conover, of the U. S. Naval Academy at Annapolis, ‘gives his experience in constructing concrete silos in North Carolina: “In connection with my work with the North Carolina Depart- ment of Agriculture, I have built during the past five years a large number of concrete and cement plaster silos and they are all giving excellent satisfaction. Where the silage was properly packed it has kept splendidly. These silos were all ' given a coat of coal tar inside before filling, which I believe is a necessity. -- ““The concrete silos had 6-inch _ fd ce nae walls reinforced with woven ee ee ee Welawines Glie, by wieaniest wire fencing all the way up. We Reinforced Silo and Cistern Block Co., of used a standard fence from 30 to Delyare, Q. Pimmtons tee cae 48 inches in height. The plastered ofother silos in this vicinity, no roof is used. silos had walls. only about. 24 inches thick, the plaster being put on expanded metal lath bent and wired in a circle. No other reinforcing was used. One of these silos has been up five years and as far as I can see it is just as good as it was when first completed. slots ck “These silos were all put up by farm labor and did not cost nearly as much as they would had they been built by such labor as one gets in the city. One silo 12x24 only cost its owner $80.00. One of the expanded metal lath plastered silos 14x28 cost $181.00 including roof, painting (tarring) and everything complete. Wood has reached such a figure and lasts such a short time that I believe it is much cheaper to build of concrete. I am not familiar with concrete silos in the North, but for the South I do not think there can be anything better. I expect to build two concrete silos 16x32 for the Naval Academy Dairy this summer.” 30 | CONCRETE SILOS What It Costs to Build a Concrete Silo ABLES E and F show the dimensions, tonnage, and actual cost of 78 monolithic and 30 block silos, compiled from data collected during the Spring of 1911. Total costs given include material, labor, superintendence and all miscellaneous expenses in- curred in putting the silos in place to receive the crops. Exchange labor has been figured im at the prevailing rates for day labor in the same communities. Where sand and gravel have been obtained. on the place, the expense of hauling plus a fair price for the materials has been included in the total cost. The following figures given in terms of cost per ton of capacity represent averages taken from the tables: ! Average Cost of Silos. Per Ton of Capacity. Monolithic. Block. [linoisi sass wees: $2.83 $2.44* Michigany7: . ..sahtis 2.31 3.21 Wrasconsin ye fs aah kt 2.10 3.36 Minnesota -Atia dt 2.26 3.34 Average cost of all silos, capacity 100 tons or less....... 2.89 Se Average cost of all silos, capacity 100 to, 200 tons. spn: 2.38 2.88 S.§, Lee, Lowell Mich, built during Didty Average cost of all R. fs engev ine, Coldwater. Diameter, 14 silos, Capac Tae y eet; height, eet. Cost, $350, complete : except for gravel and scaffold. more than 200 tons 2.18 Average cost of all silos is. Barelaenes 2.30 Sak 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. A fair average for the State would ‘undoubtedly be much higher. . UNIVERSAL PORTLAND CEMENT CO. 31 TABLE E. COST OF MONOLITHIC SILOS. . : zi x A € eee cet | Gemeciy| Rate | son ot Location 1 16 37 161 $ 525 $ 3.26 Belvidere, Illinois 2 16 44 207 695 436 ) Casiton, 4 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, ‘) 6 20 40 282 720 2.56 Dundee, 4 7 12 27 58 241 415 Effingham, ‘f 8 18 40 228 620 2.62 Elburn, ‘f 9 18 40 228 620 2.62 Elburn, $ 10 20 40 282 680 2.41 Elburn, $ 11 20 40 282 | 680 2.41 , Elburn, 4 14 16 40 180 550 3.05 , Kaneville, { 15 17 42 218 650 2.98 - Lake Forest, “ 16 17 42 218 650 2.08 Lake Forest, % 17 18 46 277 650 2335 Marengo, a 18 18 36%) 200 409 2.09 Pingree Grove, “ 20 18 34 181 490 2.70 . St. Charles, a 21 16 30 119 405 3.40 . St. Charles, . 22 20 40 282 680 2.41 St. Charles, ff 23 18 38 Bld 575 2:42 St Gharles; as 24 12 38 94 300 3195-5, Jacob; ee Wheaton, nh 27 24 50 550 | 1600 "97 Winslow, “ 29 20 40 282 500 1.76 Coldwater, Michigan, 30 20 40 282 500 1.76 Coldwater, . is) on — [e,0) ASS (=) ie) iS) (0,¢) (Sal on (=) is) a — 32 14 45 165 306 1.87 Eau Claire, ss 33 14 46 170 400 2.35 . Eau Claire, . 34 12%| 36 95 163 i472. | Hau Claire; 3s 35 14 36 118 200 1.70 . Eau Claire, sé 36 ie te 55 190 3.45 Grandville, 4 37 11 28 51 105 2.06 Hudsonville, ~ 38 14 28 83 250 3.00 Kalamazoo, ~ 39 12 30 67 250 3.72 Kalamazoo, . 42 14 30 91 130 1.43 Lansing, * 43 14 32 100 169 1.69 Lansing, i 44 18 40 228 550 2.41 Marquette, * 45 14 40 138 295 2.14 Parma, a 46 14 40 138 300 2.18 . Parma, Ye 47 12 36 87 230 2.64 Parma, oe 48 12 36 87 240 7 eet pia, : 49 12 36 87 300 3.45 Parma, A 50 14 47 175 300 1.72 Sodus, > 57 20 45 330 550 1.67 Cedarburg, Wisconsin, 58 20 45 330 550 1.67 . Cedarburg, x 61 16 30 120 500 4.16 Elkhorn, . 64 16 40 180 275 1.53 Hudson, ‘d 65 14 52 190 600 S16 | Ipma, % 66 14 36 118 17/5 1.48 Lake Geneva, 68 14 36 118 293 2.48 . Madison, : 71 16 30 120 260 216 New Richmond, “ 72 16 30 120 260 2.16 New Richmond, “ 73 16 37 161 199 1.24 New Richmond, “ 74 13 30 79 168 2.13. Roberts, 5 75 16 30 120 114 95 Roberts, ¥ 76 16 30 ~ 120 180 1.50 Roberts, ch 32 CONGRE®TE SILOS TABLE E—Continued. so Wee HSER CCAR Oana eae LOCATION No. in feet feet tons ost capacity 77 16 30 120 177 1.47 Roberts, Wisconsin 78 16 38 167 195 Lely Roberts, fs 79 ~ 14 35 114 325 2.85 Walworth, = 80 14 28 83 400 4.80 Walworth, a 81 60 40 2250 2500 Tit Waukesha, 3) 85 14 29 87 115 132 Jordan, Minnesota 89 20 32 205 380 1.85 Owattona, < 90 14 28 83 214 2.58 |Rose Creek, 93 16%} 33 144 475 3.30 Wheaton, tg 94 20 0 282 500 1.77 | Centerville, Indiana 95 16 38 167 500 2.99 |Fort Wayne, x 96 16 40 180 550 3.05 Huntington, i 97 14 300 91 340 S74 t) Oil City; 4 102 16 40. - 180 344 1.91 Roanoke, Missouri 103 16 32 - 131 315 2.40 | Springfield, My 104 12 30 67 250 3.72 |High Bridge, Kentucky 105 18 38 211 204 ‘97 *| West Pam ‘Lick, = 106 12 24 49 145 2.96 Fort Collins, Colorado 107 12 24 49 165 3.36 | Fort Collins, im 108 17 38 190 400 2.10 |lIowa City, Iowa 110 18 40 228 600 2.64 ' Warren, Pennsylvania TABLE F. COST OF CONCRETE BLOCK SILOS. Toe Rn, ee oemmnice . Plog eaeeay LOCATION in feet feet tons ai capacity 16 38 167 |$ 450 |$ 2.70 | Kaneville, Illinois 16 44 207 450 2.18 Kaneville, iE 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, ey 51 8 37 40 227 5.70 | Sodus, r 52 12 30 67 300 448 | Sodus, MG 53 2 30 67 180 2.70 | Zeeland, i 54 10 20 36 110 420 | Zeeland, . 55 10 28 42 160 3.80 | Zeeland, 56 10% 28 45 170 3.78 Zeeland, 3 59 16 34 143 340 2.38 |East Troy, Wisconsin 60: 14 35 114 300 2.64 | East Troy, i 62 14 30 91 450 4.95 Elkhorn, +g 63 18 33 174 400 2.30 | Elkhorn, ne 67 12% 38 100 500 5.00 |Lake Geneva, i 69 16 32 131 410 3.13 |New Richmond, “ 70 16 By 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 a2 3.12 | Litchfield, Fe 87 14 32 100 380 3.80 | Northfield, 88 14 32 100 375 3.75 Northfield, t 92 14 32 100 225 2.25 |Stillwater Jct, “ 98 20 60 530 750 1.42 | Delaware, Ohio 99 14 40 138 420 3.04 | Greenfield, “2 100 12 33% 80 250 3.12 Lorain, 101 12 30 67 200 2.98 | Marysville, . 109 16 344 146 475 3.25 Butler, Pennsylvania ~ caused by filling. i UNIVERSAL PORTLAND CEMENT CO. 33 Time Required to Build Concrete Silos : ike 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 De- 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 A Comparison of the Monolithic and Concrete Block Types. Two general methods of con- crete construction are available for fig. 21. Block silo of C. E. Deaner, Sodus, silo work—the monolithic and: the Mich. Although Mr. Deaner has but 17 acres concrete block. With the: former oncae eay Pigott ars. method, the materials are-hauled to Harbor, Mich., was the contractor. This the site of the silo and there mixed ‘#° W#* erected complete ee 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. 34 CONCRETE SILOS Building the Silo 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 of good system, competent overseeing and general experience in the work just 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 under contract is no greater than if built — by the owner. [If it is desired:to put up the silo during a time of year when work is over plentiful or farm labor scarce, building the silo under — contract will solve the labor prob-— lem. ‘ie C ONTRACT WORK :—Where the services of reliable concrete ; Pave 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 any 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 — 1] . ie 3 5 = 4 4 { ; Pe Cold MB We hee silos furnished the sand and gravel, owner. Diameter, 14 feet; height, 40 feet; for which they received credit on — capacity nl #itans- their accounts, at a stipulated rate. 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 te © build his own forms. at UNIVERSAL PORTLAND CEMENT CO. bP ;, Work Under Home Supervision:—If neither a good contractor nor a good foreman is available, the farmer may undertake the build- a! 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- ne 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- ST Es ie sup eRe ee Sed gether can construct moderate size Fig. 23. Monolithic concrete silo on farm of silos in an average time of less than {ager thedirection of Martin Peterson, con- two weeks, working but 4 hours per tractor. Height, 33 feet; capacity, 144 tons. 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.” S655) 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 a 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%, feet greater than the inside diameter of the completed silo. This will give the outer line of the excavation and also foundation. Figure 24. Simple sweep, convenient in laying out excavation Raat ETRE RET His rere TS Excavating :—The excavation should be carried to a depth not to 3 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 remoy- 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 %4 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. 10 0 Barn Fioo 25° A Concrete ss, Se . HN D P SV: arg ey ee Fioor 1-2b:A Concrete dy) Pitch OF FLOOR £ Tol’ 444; Wig) Vis Vee Wy Y/ > ii 4 Yi; Footines 1:3:5 ConcrRete Figure 25. Concrete Silo Footing and floor, suitable for either +. Monolithic or Block Silos a v4 Imbedding Reinforcing Rods :—If a monolithic silo is to be built, the vertical reinforcing for the walls, consisting of 14-inch round tods 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. 8 neg Footings 1, ga Floor Footings and Floor BC # gr Quantities as om Quantities Total Quantities Ee -o3 s -68 5 rel | C t| Ss Gravel sa ae (ed (Sear SS 5 Bois. Sand Osa tek VC aeieanlie aa le oem 8 1.5 1.8 | 07 14 0.5 62 25 46 2.42 | 0.93 1.86 \ 10 18 22, 0.8 1.6 0.8 1.00 By 75 3.19 1.17 2.34 12 Ded 2.7 | -1.0 2.0 1.0 1.25 46 92 3.94 1.46 2.92 | 14 2.5 3.1 12 2.4 1.6 2.00 75 1.50 5.08 1.94 3.77 16 2.9 3.6 13 2.6 22 2.75 1.00 2.03 6.33 2.31 4.62 18 Sy 4.0 1.5 3.0 2.8 3.50 1.30 2.58 7.47 2.79 5.58 20 3.6 4.4 1.6 3.2 3.5 4.35 1.60 3.22 8.74 B21 6.42 22 3.9 48 1.8 3.6 43 5.33 2.00 4.00 10.13 3.78 7.56 CED SE 38 CONCRETE SILOS ‘b—0b SO Be Oana |, G 1/6 [tl] He | 9 JOTI STHE |9 | IL ZTHE |Z |etih |8 | Pty jOrjcl| .Or—9e 1 } = #E-| S91 6.-| vI Co-S VOELSRS | 1S 1 TURZTNe | 2 CIP ea res O. OT US SRE TST 9} Sama ck ee > Cee POL OT A019 PEE ZI We eal Ny (8 | Ve Pere VERS VOLT Sto chist CL 8¢ - Sap ata ale. ee Ue | ee ‘Ip | 8 [el] “Te 16 [ST] HS JOL|STySs |2tj "49 | tyst 82—¢e tA SS vas Ls” WV 1G “OT Pi Sg OTE |S IS lle cist 71 I Serer 9 {ET} ° 14 |OLNST! -ve—02 .; : V2) > OT "WS |OL)8T SHS Tl Ib es jer ~ OS OF JPEN OTIS Noy eee lliteal! Oc IP wpe als : Fi lA “19: | et pelle elect #2 | ZT 6 Tl 8I oH aa en #9 | ST ‘ Abas! OF “18 16 Ol el ST 81 cI—8 “16 ‘tl 7 ST Wy! 3T 81 Sn I vA roe 81 3T 3I oe) 0}-WO1 yy ees ut do} woaz yyded Fae mesa rele eller | soyout ul spoa JO Jojouelcy “HW 8T “FW OL “a vl “FJ cl ‘3FOT “358 u O uaqwweuaqewnvid ‘Soyouy Uy ‘SSOTIS DIHLITONOW NI SGOU DNIOMOANIDA IVINOZIXOH AO ONIOVdS aM ATaVvL 54 CONCRETE SILOS Joining Courses:—Immediately before the concrete is placed for each succeeding course, the surface of that previously laid should be thoroughly cleaned off and moistened, and coated with a cement and water grout of about the consistency of cream. ‘This precaution is necessary to secure a good bond between the courses. It should be observed in all cases, as the pressure of the silage is apt to force moisture through any seams which might occur because of imperfect bond. Concreting should not be discontinued with a course partially completed, but if this is unavoidable the concrete surface should be left as nearly vertical as possible. Height of Wall at Each Filling:—Although the forms are made 3 feet in height, the height of the wall built at each filling (after the first) will be 2 feet 6 inches, allowing the forms to cover 6 inches of finished wall when in position to be filled again. Experiment has shown that this is about the best height to fill at one time, as it makes about one-half day’s work for the average farm crew when the mixing is done by hand. In reasonably good weather it should be possible for home labor to raise the forms each morning, refill in the forenoon and have the remainder of the day free for various farm duties. Labor Required:—The following estimate of labor required to construct monolithic silos is based on experience in a large number of cases, the materials being mixed by hand. The labor here given is approximate, and does not include that required to haul materials: Silos 8 feet 1 in diameter 10 to 14 days (4 hours per day) 4 men 12 “2 10 to tG. 6 “_ 4men ce 16 ce it 6é 10 to 16 ce ce it ec 4to5 men 6c 20 ce ce ce 10 to 20 ce ce“ ce ce 5 men ce 22 ce is3 6c 12 to 20 cé “ec ce ce 5 men Reinforcing:—Steel rods are preferable to other kinds of reinfor- cing only because they come in standard sizes, the strength of which is definitely known. Any other kind of reinforcing, such as heavy wire fencing or other ma- terial of steel, having one section rigidly attached to another will do the work equally well, and may be successfully used if a suffi- cient quantity is put in to give a cross-section area equal to that of the rods recommended in table K. Spacing of Rods :—For all silos, regardless of diameter or height, the Fig. 40. Simon Wierda silo, Zeeland, Mich., vertical reinforcing should be built of ornamental blocks with strap iron 72-inch round or twisted rods spntorcing placed ou tne onise, Croats, placed 4m the middle |of (Me wale put 3 inches thick. This silo was built in intervals of about 3 feet. The size 1905, and although of exceptionally thin 7 4 in- block, exhibits no cracks or other evidences and BEES of the horizontal rein of failure. forcing depends upon the diameter UNIVERSAL PORTLAND CEMENT CO. 55 of the silo and the distance from the top, and may be obtained for any given silo by referring to Table K. The first horizontal rods should be placed 2 inches above the foundation. Wherever rods are spliced, they must be lapped for a distance equal to 64 times the diameter, which is 16 inches for 44-inch rods, 24 inches for 3£-inch rods and 32 inches for %-inch rods. Immediately before the outer form is raised to position the horizontal rods should be wired in place for a distance equal to the height of the forms. The position of the reinforcing is very clearly shown in the ess view, Figure 61. Where a concrete cornice is put : on an extra reinforcing band is put around the top for the purpose of strengthening it. Example :—Required, the proper spacing of horizontal reinforcing rods in a monolithic concrete silo 18 feet in diameter and 44 feet in height. Referring to Table K, we run across the horizontal column at the top to “18 feet.” Referring to the figures directly below we find that four sizes of rods may be used in reinforcing a silo of this diam- eter. The first four feet of the silo, i. e., starting 44 feet from the top and running to 40 feet from the top - (see left hand vertical column) may be reinforced with 54-inch round rods 14 inches apart, %-inch round rods 9 inches apart, or 34-inch round rods 5 inches apart, as shown in the columns under 18 feet, and parallel to 40 feet—44 feet depth from top. Above this point the intervals be- tween reinforcing should be made larger, or a smaller size rod used, poeure a1. oon ent Derrick according to the table. Thus at the Sao oma en e ee ane = pai top of this silo, i. e., at a depth of Iowa State College, Ames, Iowa. 0-4 feet from the top, the reinforc- ing should consist of 14-inch rods spaced 12 inches apart. Reinforc- ing rods are sold by weight, in stock lengths. One-fourth-inch rods weigh 16:84 Ibs. per 100 feet; 34-inch round rods 37.5 lbs. per 100 feet; 14-inch rods 66.7 lbs. per 100 feet. Hoisting Materials:—The work of constructing the silo will be made much easier if a convenient method of hoisting materials is adopted at the start.. The old scheme of raising the concrete by hand with a rope and a bucket wastes time and materials and means much unnecessary labor. Materials may best be raised with a rope and pulley, the latter attached either to a derrick frame, as shown in BUCKET 56 CONCREDESIEOS Figure 41, or suspended from a frame resting on top of forms, the power in either case being furnished by a horse. The derrick shown _ in the figure may be built to any height required, in the following manner: Pieces marked “A” (2x6 inches, 16 feet long) are spliced together until a height at least 6 feet greater than that of the com- pleted walls is obtained. Pieces “B” (1x6 inches) are nailed to “A” in such a manner as to make an J-beam as shown in the sectional view in the center. The cross arm is made of a 2x6 inch piece 3 feet long spiked to piece ‘‘A’ and prevented from raising at the back end by piece ““B’’ which runs flush with the top of the arm. The brace is made by 2x6 inch material, 3 feet 2 inches long. The three No. 9 guy wires are fastened to the cross arm and brought around in grooves provided for the purpose and fastened to stakes driven in the ground for a considerable distance from the bottom of the derrick. This device, which has been recommended by the lowa Experiment Station, is said to have been tested and found safe for loads less than 400 pounds. . —Floor Line of Tank Fig. 42. Two monolithic concrete silos, built by the Polk- Genung-Polk Company for Mr. B. W. Lord, Danville, Ky. The right hand silo has a water supply tank 4 feet in depth on top. Both silos are 16 feet in diameter by 45 feet in height. FT ee ee ee, ee ee eg ee a at UNIVERSAL PORTLAND CEMENT CO. 57 ~ Commercial Monolithic Silo Systems EVERAL very ingenious systems of silo forms have been de- S vised and put into use in various parts of the country by silo contractors and construction companies. These are of a more substantial type than the home made forms and in most cases the same form may be used to build a great number of silos. Manu- facturers of these forms generally contract to build silos by their systems, but often sell the forms and territory rights or rent them to prospective builders for the job. A few of the best systems in use in the central part of this country are briefly described in the follow- ing paragraphs :* The Polk System:—This system, which is shown in its entirety in the illustration, Figure 43, is operated by the Polk-Genung-Polk Company of Fort Branch, Indiana, and a number of licensed con- tractors. The inner and outer forms are of heavy galvanized sheet iron, stiffened with angle iron. They are suspended by rods and chains from an iron collar which slides on a hollow steel mast. The Fig. 43. The Polk System in service, showing the patented metallic forms, method of raising and securing forms by the center mast, reinforcing metal, and appliance for hoisting materials. Two sections of the form are removed to permit a view within the silo. *It is hoped to give a more complete list in a future edition. 58 CONCRETE SILOS inner and outer forms are kept perpendicular and also held at proper distances apart by radial horizontal angle irons. These also serve to hold a platform. One of the chief advantages of the Polk System is the method of elevating the concrete and depositing it within the forms. The apparatus consists of a steel bucket and cable, the latter running over a pulley attached to a trolley. which travels on a steel boom. This boom is attached to the central mast by means of a collar which allows it to swing around in a full circle. After it is filled with con- crete the bucket travels upwards until it reaches the trolley on the boom. The trolley is then released automatically and the bucket travels until directly over the forms. The trolley is prevented from going further by a stop consisting of a steel pin placed through a hole in the boom. Power for elevating the materials is. generally supplied by a horse. The forms are raised in the following manner: A small flat collar is pinned in position to the mast about two feet below the collar which supports the forms. Two long jacks are then placed on the flat top of the lower collar in such a manner as to raise the upper collars when the jacks are operated. The mast is provided with holes a short distance apart to receive steel pins, and as soon as the jacks have been raised to their limit a pin is placed through the mast just below the upper cylindrical collar to prevent the form dropping while the jacks are being moved up to a new position. The forms must be loosened, of course, before any attempt is made to raise them with the jacks. The silos constructed by the Polk System have single walls six inches thick, reinforced with twisted steel rods %4-inch to 54-inch in size. They are built with elliptical door openings, one door to every five feet in height. Except where especially desired by the Fig. 44. New Enterprise Concrete Machinery Company’s silo form. The form fer the round concrete chute, at the right of the illustration is worthy of special note. The form is made entirely of steel. Ey ye cations is also used where it is UNIVERSAL PORTLAND CEMENT CO. 59 owner, roofs and chutes are not supplied. The former are considered unnecessary except in cold climates, and on most of the silos con- ‘sop ie by this company the owners have used cheap chutes of wood. The Polk System is thoroughly protected by United States pat- ents. . The New Enterprise System.—The New Enterprise forms, man- ufactured by the New Enterprise Concrete Machinery Company of Chicago, and used by the above company and a large number of silo contractors, are built of heavy galvanized sheet iron with angle iron stiffeners. Both inner and outer forms are built in sections which are coupled together with small steel pins or spikes. They are held at the proper distance apart by a steel frame which also supports a derrick. The materials are raised in a steel bucket, horse power being used. _An interesting feature of this system is the form of a semi-cir- cular chute. It is made of the same material as the silo form proper and with it the chute is run up at the same time as the silo. Reinforcing used in both silo and chute consists of heavy bull fencing. Figure 44 shows the New Enterprise form as used for constructing silos with single walls. This form with the necessary modifi- desired to build the silo with double walls. In double wall silos the re- inforcing is placed in the inner wall, which is 44 inches thick. The outer - wall is 4 inches thick and the air space between is 32 inches in width. Wall ties, made of gas pipe slotted at * nae both ends, are placed between the ees Ue Cole Eduard Hoyt Elbors, walls in each course at intervals of 3 IL, by the New Enterprise Machinery Co., feet, the slotted ends being bent so %f Chicago. 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% feet in height and two forms 60 E€ONCRETEaSILOS 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. boo 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 vaties 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, Alle. 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. ea: 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 pape on. McCoy Forms: of years Mr. John H. 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 aah 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 OLLOW concrete block silos are popular in all of the northern H 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- 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 rience. Examining Blocks:—When the work is done by a contractor, the owner should take the precau- owner does not considera roof necessary. 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 %4 inch 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 aT ’ : p ; D . -overconfidence of the builder in 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- lands 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 the strength of the blocks, or fail- Fig.50. Block silos on the farm of Henry Mieeredlize the enormous outward per ee eee ate” Built by Reine pressure of the silage. Horizontal ert,Malsch & Baumback, Lake Geneva, Wis. 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 3£-inch rod between each course of block; following up directly the 16-foot diameter column, we find that 34-inch rods must be used between each course until a point 16 feet from the top is reached. From here up %4-inch rods are used until 8 feet from the top when No. 6 rods are sub- stituted. GCONCRETERSEEOS: 64 ELCs CC9C 80S2 VOLT O877 DONE cSOC 8col vcsl OIZI 96ST cst 89LT vScl OV IT PLES SLOUAN ZOE SZ 009¢ C7 = Cea 9T8¢ ZZ = 9Sbe ZZ = 960€ £S9¢ Goa ales 69 £962 69 86rE 99 gole 99 gesz 99 6£e¢ €9 +¥z0e €9 602 £9 OBIS ate 09. 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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. METHOD OF ANCHORING MODS WHEN LAPPING 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 ye en se 5 ee ee ee, ee See “care should be taken to get corre- 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 sponding holes in the two channels at exactly the same height and dis- tance from the edge. Bolts 34-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 : Fig. 52. Mr, Fa rod. Four nuts should be provided fee eect, Baldwin’s concrete block Ohio. Dimensions, 154 for each bolt. In assembling the feet in diameter by 36 feet in height. Built £ 1910. frame one nut will be placed on each 4Urin# the summer of 1910 end of each rod 2 feet 2 inches apart. The bolts will then be slipped into the #-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 threaded: the ends of the rod will be brought through the holes, drilléd 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. Ue 68 CONCRETE SIEOS Home-Made Blocks NUMBER of farmers in various parts of the country have put A 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 obama ali ofa eee 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: ; A The Anchor Concrete Stone Co., Rock Rapids, Iowa. Ashland Steel Range & Mfg. Co., Ashland, Ohio. Cement Machinery "Coe Jackson, Mich. Century Cement Machine Co., Rochester, N. Ve 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, II]. U. S. Gas Machine Co., Muskegon, Mich. - SECTION om Cb ~ 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% 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 14%4 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 l-inch planed lumber and have tapered wooden blocks 8 inches long, 5 inches wide and 7-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 | HE PERFECT SILO :—The Perfect Silo, built by the Beteet 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 % 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 Fig. 55. Two large monolithic silos on the Jelke ‘Dairy — Farm, Diundée, Ill. The combined capacity of both silos is nearly 600.-tons.-:.The silo on the-left was built, by a contractor, and thaton the right by farm labor under the direction of Mr,,.W. A. Dickinson, the farm superintendent. Both silos have concrete roofs. ; 7 : SA ee ee ee ET ee he ee ee eee ee 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. Fig. 56. Detail of Lateral and Perpendicular Reinforcing in the Perfect Silo. 1 PEAULEEILLELTEN | earavasareeoen HEM, Ue, Lam Bee (one LE AGE TEE THIN i) barenas fhAMNE = al By FN 0 ie PTT sie = 3 oS ae Hoos ne = eee REM OL TENS = C — aaa 5) He | WANG Ae We b 2 GUBELESIMETBEEN LER ee) | Fig. 57. Sectional View showing Construction of the Perfect Silo and Method of Reinforcing continuous Doorway. 72 CONCRETE SEEOS 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 % inch 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 PERMANENT chute of concrete is a valuable adjunct to any A 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 4% 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. : : Fig. 59. 165-ton silo of A. R. McNeill, Wil- Foundations:—The foundation tow Wall Poultry Farm, Old Fields, W. Va. for the chute should be 2 feet wide Cost, complete with concrete chute, $405. ; Built by R. C. Angevine, Coldwater, Mich. and 1 foot high, the same as that for the silo, using concrete of the - same proportions. (See page 36.) If a monolithic chute is to be built 34-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 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 34-inch round reinforcing rods so spaced as to correspond with the rods binding the chute to the silo, so that they may 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. = 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. an aa \ aa YA eS [eure Ss) Fig. 60. Forms for monolithic concrete chute. The illustration shows the recesses ‘“a’’ and the 34-inch re-inforcing rod used in joining the chute to the silo wall. £ . a : a Pee ee ee rn eee ee afar ee ee ite tei” tee te hn he ee Nae | ell UNIVERSAL PORTLAND CEMENT CO. ia, Continuous Doorway Wooden Doors hp N NGANNS 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. U6 76 CONGRETE) SELOS Water Supply Tanks HE top of a monolithic silo is a convenient place for the ‘tate 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- Fig. 62. Monolithic silo, built for the Agri- t cultural Guild of the University of Chicago QUEST. by J. H. McCoy (Steel Concrete Construc- : i tion Co., successors), Harrisville, Pa. This Planning for the Tank:—lf a silo is 47 feet in height, and contains a 250- {tank is to be built on top of the silo, barrel water tank within the top four feet. 5 s : 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 atank 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 door-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 34%4 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 ¥%-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. eee Te ee see UNIVERSAL PORTLAND CEMENT CO. 77 TABLE N CAPACITY OF WATER SUPPLY TANKS * Diameter of Capacity in tank in ft. barrels 60 10 95 2 135 14 185 16 240 *Depth of water—5 feet. One barrel equals 31.5 gal. or 4.21 cu. ft. Dae AT ME ES ie BR: Toy Aaa Rs SouZzee JO Re KO UINED.. RO D's jinen |_| inen aoe JE ESE ees nN 7 Lustance ftom of fop of saat Ww yn Ue Loth. ee te ee ieee Use Zork but sot bath 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 Fee : coe Soi et A pees , Re eee o taite “ yk he fe oat sig ss ® 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. 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 21%4 parts clean, coarse sand, and 4 parts of screened gravel, the latter to contain no particles smaller than %4 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: TABLE O. MATERIALS AND REINFORCING FOR TANK FLOORS Diam. Total Sand | Gravel | pounas of Spacing of and | thickness ees rea’d. req’ ae ene Eo ore No. of reinforcing tank of ats cu. cu. reinforcing | reinforcing lengths rods of silo floor yds. yds. _| Teds rea’d. | rods req’d. (inch. apart) 8 62-in. 6 in. to 8 in. 10 7 = 4 oe 66 8 (79 12 8% ce Oe 8 (13 14 10 ce 5 Qe ce ce OE t3 10 4 8 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 ee ee ee ee ae A eee Se as 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 2-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. Kaneville, Ill. Diameter, 16 feet; height, 44 : br feet. Built in 1910 from block manufactured Example: _ Suppose it is de- Pas eras 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—%3g inch and % inch—are used. Running to the bottom of the vertical dia- grams, it will be seen that a 34-inch rod is placed 2 inches from the floor line. The next two rods are also 3%-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 3-inch rods may be used, and the change made to %4-inch rods at a point 2 feet 5 inches from the top. Piping and Overow:—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. 81 The Concrete Roof HE 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 concréte 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 Se followed, little difficulty will be 2 aa found in putting on a good roof of _ Fig. 66._ 100-ton concrete block silo of John concrete—one that will last in- Bets-Gepeys. Wis, Built by owner in 0. definitely without need of being cheslong,6 inches high, and 8 inches thick. 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” strap 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 1”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. 82 CONCRETE ‘SILOS 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. Bea ee. The roof frame may be boarded a Chin ag ot . up as shown in the plan view, Rn Lo oe with boards running either rad- CaN ially or otherwise, as desired. < These boards should be placed Us 44x 2 Bracket close together 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 22 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 sat covered with old newspaper, forts if) place for building paper, or similar ma- : : terial, which will prevent the /0p Section and Cornice concrete from sticking to the forms. This will greatly facil- itate their removal. Ipside tort a Qiside torr? 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 foot apart on thecinemm. ference, and the latter so Fig. 67. Mold box for Silo Cornice that the distance between the UNIVERSAL PORTLAND CEMENT CO. 83 == ae | =e \, ° oO; ° 5 Ss Use £ ROUND BARS CONCRETE TO BE 123 MIXTURE 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 ona one-inch bed and be covered by a three-inch bed, the total thick- ness of the roof being fourinches. For amounts of reinforcing ne- cessary for roofs of various dia- meters, see table P. 3 7 i Concreting :— Concrete for the roof should be made in the proportion of one sack of cement 3 to two cubic feet of coarse, clean : sand, to three parts of screened more Farm, Lansing, Mich. Diameter, 12 feet; gravel. The concrete should be height, 38 feet. Cost, complete, about $180.00; mixe i capacity, 94 tons. Bevel faced blocks were : d as wet as it can be put oR used, and the inside finished with 1:2 cement without danger of running to and sand mortar. 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 a ee ee Se eS ee ee ee ee ee ae — =-— as” =. ey ea ee Sa eee ee ee ~ "9 CONCRETE SILOS 85 TABLE P DIMENSIONS AND MATERIALS FOR ROOFS For Silos with Diameters 8 feet to 22 feet | Diam- ann Cement Sand ae t INcH REINFORCING Rops eter of renee required | required | required No. of Stock No. of Silo cu. yds. cu. yds. rods length pounds required of rods _| ofrods 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 134 bbls. of cement, % cubic yard of sand, and 34 cubic yards of stone, approximately. The 14-inch reinforcing rod weighs .167 pounds per lineal foot. solid, namely, made without cores, or 1f 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 SIL@S L — ; : ' 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 ata 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. 73. F. W. Merrill’s concrete block silo, Kareville, Ill. Made with patented block manufactured by Mr. Merrill. Cost, $450; capacity, 160 tons. This silo was put up complete in 4 days. 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. coe Fig. 74. C. Shaw’s monolithic concrete silo, New Augusta, Indiana. ‘ f 4 UNIVERSAL PORTLAND CEMENT CO. 87 Booklets for Free Distribution. . EN 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. 88 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. 2 The Crown Press, Chicago 1s - Me ae a i. OF CONGRESS aT Ai HH a Sampling— Universal Portland | Cement four hun- dred and fifty times an hour as the finished product leaves the mill | is one illustration of the thorough- | Na ness 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 a