. Tests of eighteen concrete columns reinforced with cast rs were tested as near atpossible on the days on which the same numbered columns weretested. Compression readings were made with an electrical con-tact micrometer compressometer on an 8-inch gage length uponall cylinders. The micrometer used in this compression work readdirectly to inch. The cylinders were well made, but the small number does notwarrant the drawing of any very definite conclusions as to therelative merit of the concrete in the various columns. The stress-strain diagrams for all cylinders is given in Fig. 4
. Tests of eighteen concrete columns reinforced with cast rs were tested as near atpossible on the days on which the same numbered columns weretested. Compression readings were made with an electrical con-tact micrometer compressometer on an 8-inch gage length uponall cylinders. The micrometer used in this compression work readdirectly to inch. The cylinders were well made, but the small number does notwarrant the drawing of any very definite conclusions as to therelative merit of the concrete in the various columns. The stress-strain diagrams for all cylinders is given in Fig. 4. 2. CAST IRON Tests were made of five cylindrical cast-iron specimens 6 inchesoutside diameter, 4^ inches inside diameter (the same sectionused in the cast-iron reinforcement in 10 of the 18 columns), andof the following lengths: (a) One special test specimen 2 feet long. (6) Two 2-foot sections, the same dimensions as (a), cut fromthe ends of columns 9 and 10 at the Bureau of Standards, num-bered 9-a and 10-a. 14 Technologic Papers of the Bureau of Standards. o o o o o o o o oo o o o o p o in 10 o in o to ^ K) (0 jiod *»I — U| •bff •eqi 993^19 Reinforced Concrete Columns 15 (c) The remaining 8-foot sections of columns 9 and 10 aftersections 9-a and 10-a had been cut from these columns as receivedat the Bureau. Both ends of all specimens were very accurately and finelymachined. Cast-iron plates 1 inch thick were used as bearingsduring the test of these specimens. Stress was applied and strainreadings taken on 8-inch gage length at increments of 5000 poundsper square inch, until the large strains indicated danger fromfailure. At this point readings were discontinued and the loadcontinuously increased until failure occurred. Fig. 5 gives the
Size: 1307px × 1911px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidtestsofeight, bookyear1919
