XXVI. ABSTRACT OF PROCEEDINGS. 



and abroad, showing its varied and general use for numerous 

 purposes. 



2. "Further Experiments on the Strength and Elasticity 

 of reinforced Concrete," by Professor W. H. Warren, 



M. Inst, C.E., Wh. Sc. 



The author stated that the paper consisted of an experi- 

 mental investigation of the physical properties of Portland 

 cement mortars and concrete when reinforced with steel, 

 and the work described was a continuation of the work 

 described in a paper read before the Royal Society in 

 December, 1902. The real difficulty in obtaining correct 

 calculations on steel-concrete work consists, mainly, in the 

 want of knowledge existing of the physical properties of 

 the materials used, and hence it becomes important to know 

 the coefficient of elasticity of concrete in tension and com- 

 pression under various stresses, also the manner in which 

 it behaves when reinforced in various ways. The first 

 part of the paper consists of a description of the methods 

 employed in testing the specimens in tension, compression, 

 and cross-breaking. The loads were applied by means of 

 the University testing machines, and the effect produced 

 was accurately determined whether it was an extension, a 

 shortening, or a deflection of the piece, by means of Martens' 

 mirror extensometers. The results obtained, the strength 

 and coefficient of elasticities were recorded in numerous 

 diagrams and tables. Experiments were made and discussed 

 on the reinforcement of concrete columns in buildings with 

 longitudinal steel rods, grills of steel, and hooped by means 

 of soft iron or steel spirals, which has special reference to 

 fireproof construction. The method of calculating the 

 strength of steel-concrete structures was discussed in con- 

 siderable detail, and numerous diagrams and equations were 

 given illustrating the application of the results obtained in 

 the experiments, and also giving simple rules for the guid- 



