. Electric railway journal . weretested. The purpose of the test was to determine notonly the stress-strain diagram for the poles but also thebest method of placing the reinforcing rods. The poles were 7-in., 30-ft. poles made of concrete of a mixture of onepart cement, twoparts sand and twoparts of stone. Thereinforcement forpole No. 1 consistedof four %-in. twist-ed rods 29 V2 ft. longplaced in the cor-ners and four 23-ft. rods, fourV^-in. x 16-ft. rodsand four l/2-in. x8-f t. rods evenlyspaced along thesides. The sameconstruction wasused in pole No. No. 2 was con-structed the
. Electric railway journal . weretested. The purpose of the test was to determine notonly the stress-strain diagram for the poles but also thebest method of placing the reinforcing rods. The poles were 7-in., 30-ft. poles made of concrete of a mixture of onepart cement, twoparts sand and twoparts of stone. Thereinforcement forpole No. 1 consistedof four %-in. twist-ed rods 29 V2 ft. longplaced in the cor-ners and four 23-ft. rods, fourV^-in. x 16-ft. rodsand four l/2-in. x8-f t. rods evenlyspaced along thesides. The sameconstruction wasused in pole No. No. 2 was con-structed the sameas the standard polewith the exceptionthat three of thecenter rods on eachof the two sides 5000 4000 3000 2000 1000 00 I I Pole j-f— Pol ~Po7e 1 —1 25 5 10 15 20 Deflection in Inches Electric Ry Journal Stress-Strain Diagrams of Con-crete Poles 30 were placed back of the rods on a compression and ten-sion side. Pole No. 3 was constructed the same as thestandard pole with the exception that a web reinforce-. Conerete Pole No. 3, Failing under a 5000-Lb. Pull—BrokenPole in Rear ment of No. 8 steel wire was wound around the vari-ous reinforcing rods at intervals of 5 in. throughoutthe length of the pole. All of the poles were agedfrom four to four and a half months. Poles No. 2 and 3 were tested simply to determine 782 ELECTRIC RAILWAY JOURNAL [Vol. XLIII, No. 14. whether or not the bunching of reinforcement on thetension and compression sides, or the installation ofweb reinforcement, would produce enough greaterstrength or stiffness over the standard method of con-struction to warrant the expense of the additional re-inforcement, or the inconvenience produced by thenecessity of placing poles like No. 2 with a bunchedreinforcement in such a position that the tension andcompression sides would always be perpendicular to thedirection of the stress. For testing purposes the poles were set 6 ft. in theground with a rake of 9 in., and a 2-ft. ring of concrete,1 ft.
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