Document qdRELBxmG95ngeNE91KEjzQEn

FILE NAME: Concrete (CONC) DATE: 1948 June DOC#: CONC017 DOCUMENT DESCRIPTION: Journal Article - Fibrous Concrete Has High Fire Resistance Twenty Years of Progress in High Early Strength Cement Concrete___________________ 5 Veterans Open Up New Block Market Bob Downer 9 Laboratory Needs for the Ready Mixed Concrete Operator________________________ E. L. Howard 10 Pumice Concrete Houses at Muroc Air Base........... 14 The Cement Decision-- Editorial_____ _______ 16 United Air Lines Opens New Maintenance D epot__ 18 Radiant-Heated Outside Concrete Ramp ___ 20 Concrete Control on Allatoona Dam __ . _____ 22 Largest Hydro-Electric Project in Puerto Rico ... . .. 24 Double Wall of Precast Concrete Slabs___________ 26 Fibrous Concrete Has High Insulation Value___-- 30 Flexure Tests Show Strength of Jetcreted Dry Wall Block Panel________________________________ 32 Stearns Management Changes Announced___ __ _ 36 1949 Concrete Industries Exposition To Rate Top Interest of Products Men______________ 40 News from the Manufacturer___ _________ ____ 43 Good Books on Concrete___________ 52 Fibrous Concrete Has High Fire A LIG H TW EIG H T liber concrete, several times more resistant to damage by fire than normal sand-ce ment concrete, was developed at the University of Michigan during the war according to a research report on light weight aggregate materials now on sale by the Office of Technical Serv ices, Department of Commerce. The document is a final report on wartime research sponsored at the educational institution by the Office of Production Research and Development of the W ar Production Board. According to Corwin D. Willson, engineer in charge of the research project, fiber concretes are extremely resistant to fire. A 2-in. cube, placed over a large Bunsen burner flame for 20 minutes, will char to a depth of yi in., whereupon this charred portion serves to insulate the balance of the specimen against disintegration. Due to the poor thermo-conductivity of fiber concrete, the dehydration of the cement matrix does not proceed as rap idly when the surface of the specimen is subjected to high temperatures as in normal sand-cement concrete, M r. Willson explains. Fiber concretes were one of many types of lightweight cement-bonded aggregate compositions investigated. The object of the research was to in vestigate ``hard-setting, lightweight plastic compositions having lattice of fibrous materials, a binding matrix of portland cement, and a chemical ad mix ; and suited to be formed by ma chine into a sheet, or into an insulative panel or floor covering in building con struction, or to be poured, sprayed, or otherwise manually or mechanically applied in factory of field fabrication." The composition sought was to be re sistant to fire, rot, and termites, and suited to exterior exposure. 8 Thousand Specimens More than 8 thousand specimens from 225 different materials were pre pared and examined. A large number of these compositions had specific m er its. One such composition was a solidi fied " foam" that is actually lighter than cork. In the density range of about 75 lb. per cubic foot, some of the com p o s itio n s developed compressive strength of above 4 thousand psi. and tensile strength of 750 psi., the re port states. In the density range of 4050 lb. per cubic foot, approximating the weight of hard wood lumber, many of the compositions showed sufficient strength to be of practical use in build ing construction. The report contains the names and physical and chemical compositions of raw materials used and the newly-cre ated compositions. Man)- types of or ganic fibers including balsam fiber, St. Louis cottonwood wool, and yellow pine fiber, were found promising. Cot ton, flax and rice by-products and many other types of fibers cheaply available as farm or industrial wastes were also found suitable, the report states. The best inorganic fiber tested was crude ground asbestos of the type commonly used in furnace insulation. The report contains numerous tables summarizing test data on various com positions. One of these tables presents Universal W ill Make Small Sanitary Pipe At Rochester Plant TO H E L P alleviate the shortage of sewer pipe for construction, the Universal Concrete Pipe Co. has added the manufacture of small size sanitary sewer pipe in an expansion move at its Rochester, New York, plant. L. E. Barrett, local sales repre sentative for the company that has 15 plants in eight states, reports that pipe-making machinery has been in stalled to produce 4, 6, 8, 10, and 12in. diameter pipe. Previously, this plant concentrated on manufacturing large-diameter reinforced concrete pipe ranging up to 72 in. Universal, which has been in the pipe-making business for the past 27 years, also has added the manufacture of concrete masonry units to its Ro chester plant. Fittings for the small-size concrete pipe also are ready for delivery under the stepped-up production schedule. The small pipe is made on a spinnertype machine. Universal has plants in Syracuse, Port Washington, and Binghamton, New York; as well as in New Jersey, Pennsylvania, Georgia, Alabama, W est Virginia, Tennessee, and Ohio. Resistance test results of 50 separate batches using various amounts of by-product cotton. The research engineer states th at, "with no great amount of additionalstudy, cotton by-products may be used; successfully in the manufacture o f. boards, panels, shingles, pipe, tile, etc.",; Several appendixes to the report; give a detailed analysis of experience; with various types of admixes, ce-i ments, wetting agents, chemicals and' fibers, and batch test averages for the test cubes prepared. Mimeographed copies of the 185-; page report (PB-2573; Properties of assorted light weight aggregate mate- \ rials) sell for $2. Orders should be ad-; dressed to the Office of Technical Serv- . ices, Department of Commerce, W ash-: ington 25, D.C., and should be accom- j panied by check or money order, payable to the Treasurer of the United ! States. Cement Production is up 6 Per cent Over February 1947 Output PRODUCTION of 13.347 million barrels of cement in February 31 1948, as reported to the Bureau of j Mines, United States Department of j the Interior, was 6 per cent above that i reported for February 1947. Seventy,^ per cent of capacity was utilized, an,; increase of 2 per cent over that re ported for February 1947. Mill ship-1 ments reached 8.338 million barrels in ] February 1948, a decrease of 1 pen cent from that reported in February off the previous year. Stocks of 20.3451 million barrels on Feb. 29, 1948 were! 1 per cent above those reported f o ri February 1947. Clinker output in Feb-: ruary 1948 reached 14.444 million^ barrels, an increase of 7 per cent over that reported for February 1947. Demand for cement in February |j 1948, as indicated by mill shipments, .8 is still above the 1935-39 average. The : | decline of 1 per cent below the Febru- | ary 1947 figure was caused largely by a reduction in shipments from the 8 Great Plains states, from Texas north | to Minnesota and South Dakota. The long-term trend in production of finished portland cement continues its upward course. (Twenty (C< [planned, s |it possible [and lost-n [profit. "During [principle 1 (constructic [strength pc | in 24 hour.; that forme for longer, [has enable; ["cancel out I for concret P productive > In conch | says : "Design ; H obtained v j, cement hav |g of concret; I possible to j fire-safety which com If permanent Veterans ( Con [constructioi to 1946. j | | Thomas, w t in the Sou; [during the Malia an [that their i [grow as the (orders for Ihouses, and tebmrnerci. planned, it dll prove ti ation is t' perchandisi riimnee C ( Com Jet engine ^strict, Cor n complt ^ver to Co j*S officer o 1E. Ferga Corps o *hon, con the Will fein direct i an Fibrous Concrete Has High Fire Resistance A LIG H TW EIG H T fiber concrete, several times more resistant to damage by fire than normal sand-ce ment concrete, was developed at the University of Michigan during the war according to a research report on light weight aggregate materials now' on sale by the Office of Technical Serv ices, Department of Commerce. The document is a final report on wartime research sponsored at the educational institution by the Office of Production Research and Development of the W ar Production Board. According to Corwin D. Willson, engineer in charge of the research project, fiber concretes are extremely resistant to fire. A 2-in. cube, placed over a large Bunsen burner flame for 20 minutes, will char to a depth of % in., whereupon this charred portion serves to insulate the balance of the specimen against disintegration. Due to the poor thermo-conductivity of fiber concrete, the dehydration of the cement matrix does not proceed as rap idly when the surface of the specimen is subjected to high temperatures as in normal sand-cement concrete, M r. Willson explains. Fiber concretes were one of many types of lightweight cement-bonded aggregate compositions investigated. The object of the research wras to in vestigate ``hard-setting, lightweight plastic compositions having lattice of fibrous materials, a binding matrix of portland cement, and a chemical ad mix ; and suited to be formed by ma chine into a sheet, or into an insulative panel or floor covering in building con struction, or to be poured, sprayed, or otherwise manually or mechanically applied in factory of field fabrication." The composition sought was to be re sistant to fire, rot, and termites, and suited to exterior exposure. 8 Thousand Specimens More than 8 thousand specimens from 225 different materials were pre pared and examined. A large number of these compositions had specific m er its. One such composition was a solidi fied " foam" that is actually lighter than cork. In the density range of about 75 lb. per cubic foot, some of the com p o sitio n s developed compressive strength of above 4 thousand psi. and tensile strength of 750 psi., the re port states. In the density range of 4050 lb. per cubic foot, approximating the weight of hard wood lumber, many of the compositions showed sufficient strength to be of practical use in build ing construction. The report contains the names and physical and chemical compositions of raw materials used and the newly-cre ated compositions. Many types of or ganic fibers including balsam fiber, St. Louis cottonwood wool, and yellow pine fiber, were found promising. Cot ton, flax and rice by-products and many other types of fibers cheaply available as farm or industrial wastes were also found suitable, the report states. The best inorganic fiber tested was crude ground asbestos of the type commonly used in furnace insulation. The report contains numerous tables summarizing test data on various com positions. One of these tables presents Universal W ill Make Small Sanitary Pipe At Rochester Plant TO H E L P alleviate the shortage of sewer pipe for construction, the Universal Concrete Pipe Co. has added the manufacture of small size sanitary' sewer pipe in an expansion move at its Rochester, New York, plant. L. E. Barrett, local sales repre sentative for the company that has 15 plants in eight states, reports that pipe-making machinery has been in stalled to produce 4, 6, 8, 10, and 12in. diameter pipe. Previously, this plant concentrated on manufacturing large-diameter reinforced concrete pipe ranging up to 72 in. Universal, which has been in the pipe-making business for the past 27 years, also has added the manufacture of concrete masonry units to its Ro chester plant. Fittings for the small-size concrete pipe also are ready for delivery under the stepped-up production schedule. The small pipe is made on a spinnertype machine. Universal has plants in Syracuse, Port Washington, and Binghamton, New York; as well as in New Jersey, Pennsylvania, Georgia, Alabama, W est Virginia, Tennessee, and Ohio. test results of 50 separate batches using various amounts of by-product cotton. The research engineer states th at, "with no great amount of additional'! study, cotton by-products may be used; successfully in the manufacture of< boards, panels, shingles, pipe, tile, etc.", Several appendixes to the report; give a detailed analysis of experience! with various types of admixes, ce-i ments, wetting agents, chemicals and : fibers, and batch test averages for the{test cubes prepared. Mimeographed copies of the 185-: page report (PB-2573; Properties of | assorted light weight aggregate mate- ; rials) sell for $2. Orders should be ad- J dressed to the Office of Technical Serv- ( ices, Department of Commerce, W ash-; ington 25, D.C., and should be accom panied by check or money order i payable to the Treasurer of the United States. Cement Production is up 6 Per cent Oyer February 1947 Output PRODUCTION of 13.347 million' barrels of cement in February 1948, as reported to the Bureau of Mines, United States Department of; the Interior, was 6 per cent above that reported for February 1947. Seventy,; per cent of capacity was utilized, an, increase of 2 per cent over that re-i ported for February 1947. Mill ship ments reached 8.338 million barrels in February 1948, a decrease of 1 per; cent from that reported in February of; the previous year. Stocks of 20.345; million barrels on Feb. 29, 1948 were. 1 per cent above those reported for February 1947. Clinker output in Feb-J ruary 1948 reached 14.444 million; barrels, an increase of 7 per cent over that reported for February 1947. Demand for cement in February 1948, as indicated by mill shipments, is still above the 1935-39 average. The decline of 1 per cent below the Febru ary 1947 figure was caused largely by a reduction in shipments from the Great Plains states, from Texas north to Minnesota and South Dakota. The long-term trend in production of finished portland cement continues its upward course. Manned, s [it possible [and lost-n Iprofit. "Durini: iprinciple l fconstructic I strength pc |in24hour.`| that forme for longer, |has enable fcancel out I for concret ?productive In conch says: "Design ; ; obtained v , cement hav of concrete possible to fire-safety [which com "permanent Veterans > ( Coil ir fconstructioi | to 1946. gThomas, w t i n the Som [during the Malia an [that their i igrow as the torders for Ihouses, and lipommerci, planned, it gtill prove ti ation is t' Oerchandisi Jpjj ( Coi fillet engii pstnet, C gyn com] Hver to ( % officer E. Fer Corps dton, ci the W .in direc