EFFECT OF TENSILE STRENGTH OF STEEL FIBERS ON STRUCTURAL AND RESIDUAL RESPONSE OF RCC & SFRC BEAMS UNDER STATIC AND IMPACT LOADING

Abstract

Current research experimentally investigates the effect of tensile strength of steel fibers on structural and residual response of RCC and SFRC beams under quasi-static and drop hammer impact tests. Three variants of tensile strengths were used as High, Medium and Low strengths and incorporated at 1% of concrete volume. First set of Four beams (1 RCC and 3 SFRCs) tested directly under the quasi-static load (three-point bending) for Pre-Impact Evaluations and second set of beams were subjected to single impact using drop hammer test (Single Impact) and then loaded monotonically under quasi-static conditions for the post-Impact response analysis. Third set of beams were subjected to multiple impacts to understand impact resilience of steel fibers under multi-impact loadings. The results demonstrate that steel fiber tensile strength changed the failure type from punching shear to flexure-shear and then ductile flexure. Steel fiber Tensile strength improves the Structural and residual response in terms of flexural strengths, Stiffness, Ductility, and Toughness indices, residual strength factors and strengths. Improving Tensile strength has controlled the crack width and displacements before and after impact as determined under static test. Steel Fiber Strength improved impact resistances in term of displacements, Impact Force, DIF and Energy Dissipations under single and multiple blows. Current research proposes an efficient drop hammer method with minimum losses along with testing procedures for carrying the impact test.