دانلود رایگان مقاله انگلیسی عملکرد ضایعات پلاستیکی در تیرهای بتنی تقویت شده فیبر دار - الزویر 2018

abstract

Synthetic plastics are typically discarded, thus causing environmental pollution. Plastic wastes are recycled as fiber in concrete to solve this problem. In this study, synthetic fibers in a concrete matrix were investigated through compressive strength, splitting tensile, fracture energy, and flexural beam tests. The results show that an increase in fiber content improves the tensile strength of the concrete matrix. A high fiber content results in a substantial amount of fibers crossing a fractured section, thereby activating failure resistance mechanisms. Ring-shaped fibers, which are mainly designed to activate fiber yielding instead of fiber pullout, are better than irregularly shaped polyethylene terephthalate and waste wire fibers. Incorporating plastic fibers into concrete does not significantly change the failure mode of reinforced concrete beams compared to that of normal concrete beams. However, the first crack load presented improved results. The reinforced concrete containing ring-shaped plastic fibers with a width of 10 mm (RPET-10) exhibited remarkable results during the first crack load with an increment of 32.3%. It can be concluded that ring-shaped PET waste produces fiber concrete with a performance comparable to that of commercial synthetic fibers.

4. Concluding remarks

The failure mode of the reinforced concrete beam specimens confirmed the theory that reinforced concrete beams should fail due to yielding of tensile reinforcement and not because of sudden fatal compression failure. These trends were observed in all reinforced concrete beam specimens. Therefore, the reinforced concrete beam specimens with fibers did not affect the control behavior of the strain profiles of the beams during the yield and ultimate load.

The experiments confirmed that adding RPET-5 or RPET-10 fibers to the reinforced concrete beams did not lower the deflection behavior of the control reinforced concrete beam specimens. During the cracking stage, concrete beams containing RPET-10 showed that the strength of the first crack improved by 32.3% compared to normal concrete beams. The results of the relative ductility (ultimate load) of the reinforced concrete beam specimens with RPET fibers were insignificant compared to those of normal reinforced concrete beams, except for the reinforced synthetic FC beams. However, adding RPET fibers to the reinforced concrete produced significant results, particularly in the linear elastic region.