Experimental investigation and statistical evaluation of the effects of steel fiber aspect ratio and fiber rate on static and dynamic mechanical properties of concrete

Abstract

Static and dynamic mechanical properties of steel fiber concretes were determined by experiments conducted on concretes produced using fibers of different volume ratios and aspect ratios, and variance analysis was applied to the experimental results and evaluated statistically. Flexural toughness, static and dynamic elasticity modules and Poisson ratios of steel fiber reinforced concrete (SFRC) were determined experimentally. Load-deflection curves under flexural loading and stress-strain curves under compressive loading were obtained and compared with each other. The most influential variable was aspect ratio of fibers affecting each feature. As the aspect ratio increased, the static elasticity modulus of concrete increased by 29.66 %, the dynamic elasticity modulus increased by 21.58 % and the Poisson ratio increased by 27.46 % compared to the control sample. The Poisson ratio of SFRC varies between 0.1825 and 0.246. A relation was obtained between static and dynamic modulus of elasticity. Mechanical properties were improved by using steel fibers with low amounts but high AR values. To achieve high flexural toughness, static and dynamic elasticity modules and Poisson ratio, aspect ratio of fiber should be increased.