Compressive Behavior of Steel-Fiber-Reinforced Concrete with a High Reinforcing Index

Abstract

Compression tests on cylinders were performed to characterize the compressive stress-strain behavior of steel fiber-reinforced concrete (SFRC) with a high reinforcing index. The reinforcing index, defined as the product of the volume fraction and the aspect ratio of the fibers, of steel fibers examined was as high as 1.7. Hooked-end fibers of various lengths and aspect ratios were considered. The test results indicated that a higher reinforcing index was associated with a higher strain at the peak stress and a higher toughness of SFRC, up to a reinforcing index approximately equal to that corresponding to a 2% fiber volume fraction. Adding steel fibers had little effect on the modulus of elasticity and compressive strength of SFRC. Long steel fibers and fibers with a lower aspect ratio resulted in a larger increase of the toughness of SFRC. On the basis of the test results, analytical models of the stress-strain curve in compression and toughness of SFRC with a reinforcing index up to 1.7 are developed.