Investigating the effect of Fibers on the Mechanical properties of Lightweight Polyester Polymer Concrete

Due to its desirable properties, polymer concrete is used for repairing or building structures that require both mechanical strength and high durability in a short period of time. On the other hand, reducing the weight of polymer concrete by using light aggregates can double the benefits of using this type of concrete in practical cases in order to make it easier to repair damaged concrete or use it in special conditions. Since the increase in concrete strength usually results in a decrease in ductility, therefore, the use of fibers in the concrete matrix can largely compensate for the problem of the decrease in ductility. The aim of this research is to investigate the mechanical properties of lightweight optimized polyester polymer concrete (with and without fibers) and compare it with the mechanical properties of lightweight concrete. To check the mechanical properties of polymer concrete, compressive strength, tensile strength, flexural strength, impact resistance and abrasion resistance tests were used. Also, electron microscope (SEM) images were used to investigate the effect of fibers on the microstructure of polymer concrete samples. The results showed that in line with the remarkable improvement of the mechanical resistance of polymer concrete compared to light concrete, the addition of fibers can improve the mechanical properties of polymer concrete. In this study, the use of 0.25 percent by volume of composite fibers in the mixing design of polymer concrete increases the compressive, tensile, flexural, and abrasion resistance by 9.1, 8.8, 6.2, and 6.3 percent, respectively, compared to polymer concrete without It is fiber. The analysis of SEM indicates the continuity and cohesion of polypropylene fibers and polymer concrete matrix, which can be considered as a good justification for improving the mechanical properties of polymer concrete containing fibers.