Development of Stress Block Parameters for Steel Fibre Reinforced Rubcrete

Abstract

Ductility is the key parameter that influences the seismic resistance of any structural member. The presence of high yielding materials like rubber in concrete will help in improving the ductility of most commonly used construction material concrete, which is otherwise a brittle material. Such a material formed by partially replacing the aggregates of concrete with rubber is termed as rubcrete. Even though rubcretehas many advantages like improved energy absorption capacity, good ductility, better freezing-thawing resistance, etc., the addition of rubber in concrete usually reduces its compressive strength and tensile strength. Research shows that this reduction of strength can be controlled to a reasonable extend by using pre-treated crumb rubber taken in proper gradation along with the addition of steel fibre. This new cementitious composite material formed by combining crumb rubber and steel fibre in concrete is termed as steel fibre reinforced rubcrete (SFRR). New stress block parameters are required for the design of flexural members made using these new composite materials.So, in this investigation new stress block parameters were developed for rubcrete and SFRR, which can be used for concrete mix having 28-day cube (150mm 150mm 150mm) compressive strength varying from 10-60 MPa. Availability of these design parameters will enable the designers to easily carry out the design of flexural members made using rubcrete and SFRR