BEHAVIOR OF HIGH STRENGTH FIBER REINFORCED CONCRETE IN TRIAXIAL COMPRESSION

Abstract

The objective of the present investigation is to experimentally determine the behavior of high strength concrete as compared to normal strength concrete. High strength concrete is a brittle material and shows reduction in ductility with increase in strength. To improve the ductile behavior of high strength concrete, confinement is prdvided which increases the ductility as well as its peak stress and peak strain. Further, the addition of fibers to confined concrete also adds to increased ductility. The experimental programme consisted of casting and testing of cylindrical specimens of size 54 x 108 mm. These specimens include both plain and fiber reinforced specimens of three grades namely M 30, M 50, M 70. The effect variable concrete grades, volume fraction and confining pressure were studied. Round crimped steel fibers having an aspect ratio of 3 lwere used for all fiber reinforced concrete specimens. All specimens were tested after 28 days under triaxial compression. From the data collected form the test a comparative study was carried out for increase in strength and ductility for all the grades of concrete. The stress—strain curves are also shown from the data obtained from the test.