Experimental study on four-point cyclic bending behaviours of concrete with high density polyethylene granules

Abstract In recent years, plastic pollution has become more serious. The incorporation of waste plastic into concrete as part of the aggregate not only greatly reduces the environmental pressure, but also lowers the cost of concrete. In order to investigate the effect of plastic content on the mechanical properties of concrete, the MTS322 device was used to perform four-point bending monotonic and cyclic loading tests on concrete specimens with six contents of high density polyethylene (HDPE) granules. The test results show that with the increase of HDPE granule contents, both the tensile strength and the initial elastic modulus of concrete with HDPE granules declined gradually, while the peak strain increased. The plastic strain during the loading process was not affected by the HDPE granule content, but increased with the increase of unloading strain. According to the degradation of secant modulus during the cyclic loading process, the damage was defined, based on which the cyclic stress-strain model of concrete with HDPE granules was obtained. According to equations provided, the predicted model was in good agreement with the test results.