The influence of straw and plastic fibers on behavior and strength of concrete mix

Abstract

The straw and plastic fibers are used in concrete mix, to minimize crackswidthafter shrinkage and creep .Various types of mentioned admixturesare needed in concrete to eliminate cracks, and to increase strength of concrete and to make it more ductile. This research presents a discussion of two types of fibers used to reinforce concrete, such as straw and plastic fibers, separately and together, and this application is necessary to improve the concrete performance in its strength and ductility .Furthermore, this application is very important to achieve a limitation of the cracks, that may appear in concrete after its hardening. Plastic fiber can be produced from the plastic threads and waste propylene,that are considered as waste materials after uses. Straw fiberis produced after harvesting thewheat, the straw waste is costly and noisy to eliminate by burning.A huge amount of plastic disposal as well as straw waste materials, cause a climate pollution. Using these both disposal materials in concrete mix (as an admixture) of different portions such as: 0.5%, 1.5% and 2.5% by weight of sand, will improve the ductility, and will inhibit the crack propagation. The paper is focused on testing different specimens of concrete mixes (cubes and cylinders)in order to investigate crack propagation, as well as to calculate both the concrete compression and tension.