140 W. H. WARREN. 



FURTHER EXPERIMENTS on the STRENGTH and 



ELASTICITY OF REINFORCED CONCRETE. 



By W. H. Warren, wh. sc, m. inst. c e., m. Am. soc. c.e., 



Challis Professor of Engineering. 



[Read before the Royal Society of N. S. Wales, September 7, 1904:.'] 



The following paper consists of an investigation on the 

 strength and elasticity of Portland cement mortar and 

 concrete when reinforced with steel rods, and is a continu- 

 ation of the work contained in a paper by the writer read 

 before the Society on December 3rd, 1902. l All the speci- 

 mens dealt with in this paper were kept in air until tested, 

 whereas those referred to in the above paper were kept in 

 water. 



Tension Tests. — The experiments made to determine the 

 behaviour of reinforced concrete in tension were conducted 

 in a similar manner to those described in the paper above 

 referred to. The specimens, clips for holding them during 

 the test, and the method of determining the extensions 

 produced under the various loads were also, except when 

 otherwise mentioned, the same in every respect. 2 



The strength of reinforced concrete or mortar when sub- 

 jected to tensile stress is governed by the adhesive strength 

 of the mortar to the metal reinforcement. In all the 

 experiments made the specimen fractured at the change 

 of section, close to the heads of the specimen held by the 

 clips, the concrete sliding longitudinally by overcoming 

 the adhesion to the metal rods. If a sufficient adhesion 

 area could have been provided between the section where 



1 Journ. Roy. Soc. N.S. Wales, Vol. xxxvi., page 290. 

 2 Figs. 1, 2, and 3. 



