The effect of using Low density polyethylene (LDPE) fibers and sika on the properties of fresh and hardened concrete

Due to the increasing growth of population and urban expansion and the accompanying increase in consumption rates, which in turn led to an increase in the amounts of plastic waste harmful to the environment, this study aims to use low-density polyethylene as an alternative to coarse aggregate, to study its effect on the mechanical properties of concrete, and a number of 6 cubes of size (150 x 150 x 150 mm) and 6 cylinders (300 x 150 mm) for each mixture, where compressive strength and tensile strength tests were conducted, which were in proportions (0, 4, 6, 8, 10%) of the weight of the coarse aggregate. In the second stage Cica was also used at a rate of 5% by weight of cement, with constant percentages of low-density polyethylene for coarse aggregate. The results showed that the minimum compressive strength at 7 days of age when adding low-density polyethylene is only 17.52 MPa for 10% and above 21.5 MPa for 4%. In the case of indirect tensile strength, the highest tensile strength is 4.98 MPa for 4% and the lowest tensile strength is 3.62 MPa for 10%. While the compressive strength at 7 days when adding low-density polyethylene and Sika was the highest compressive strength was 24.72 MPa, at a rate of 4%, and the lowest was 21.42 MPa, at a rate of 10%. Likewise, 28-day compressive strength results when using only low-density polyethylene were 31.06 MPa at 4% and the lowest was 28 MPa. The results of using low-density polyethylene and Sika were highest, reaching 32.5 MPa, at a rate of 4%, and the lowest, at 26.97 MPa, at a rate of 10%. In the case of indirect tensile strength at 28 days, the highest strength was 13.4 MPa, at a rate of 4%, and the lowest was 8.68 MPa, at a rate of 10%.