Influence of hybrid fibers on functionally graded concrete beams

Abstract

In this paper, experimental work has been focused to investigate the static behaviour of functionally graded concrete beams with mono and hybrid fibers. Initially mechanical properties like compressive, split tensile and flexural strength tests have been conducted in order to determine the optimum dosage of fibers such as polypropylene fiber and glass fiber. Furthermore, concrete beams with hybrid and mono fibers and functionally graded concrete beams have been cast for the determination of its static behaviour. The main objective of the present work is to study the static behaviour of functionally graded concrete beams with two to three different layers as well as with different proportions of mono and hybrid fibers. Functionally graded beams have been cast such as (i) with one layer of mono fibers and conventional concrete (ii) with two layers of mono fibers and conventional concrete (iii) with one layer of hybrid fibers of total fiber volume fraction as 1% and conventional concrete (iv) with two layers of hybrid fibers (v) with three layers of hybrid fibers to evaluate the influence of fibers on static behaviour. It is observed from the results that the mechanical property has been increased for the mixtures with hybrid fibers explicitly than the mono fibers concrete and conventional concrete. Also, from the static test results it has been observed that the maximum flexural strength was attained for a beam with three layers of hybrid fibers with different combinations of 1% of fiber volume fraction. Furthermore, it can be concluded that there is an increase in flexural strength of all functionally graded concrete beams with two layers of concrete made up of PP and glass fibers compared to that of two layers of mono fibers as well as conventional concrete.