The effect of adding synthetic fibers to some concrete’s properties

Fibrous concrete is commonly used in many constructions works so it reduces crack propagation and increases concrete toughness The impacts of adding PVA fibers to fresh and hardened concrete are described in this article. To achieve this, four mixtures were realized by adding different proportions of polyvinyl alcohol (PVA) fibers with a length of 8 mm, which are as follows (0.125, 0.25, 0.375and 0.5) % by volume of concrete and compared with the results of reference samples (concrete without fibers). Concrete was evaluated in the hardened state by conducting a compressive strength test and absorption test at the age of 28 days. The flow test (slump) was used to evaluate concrete in its fresh state. The results of the study indicate that the presence of PVA-fibers with (0.125%) is the optimum ratio to ameliorate the properties of hardened concrete, where the percentage of increase in compressive strength was 1.5%. Also increases the percentage of PVA-fiber enhances the flexural strength of concrete sample by increases ductile, toughness, and avoids the unexpected brittle failure of the material. The water absorption decreased at mixtures which have the percentage of fiber (0.125, 0.25) % and increases in the percentage (0.375, 0.5) %. and the amount of water absorption decreased by 8.38%. The workability of mixtures decreases as the percentage of PVA-fiber increases, according to the results of testing concrete samples in the plastic state.