Plastic Coarse Aggregates with Low- and High-Density Polyethylene with Improved Shore Durometer Hardness as Partial Replacement to Natural Coarse Aggregates

One of the issues in engineering field is the massive demand of natural aggregates in building, which in some areas causes shortages in supplies. While globally, increasing production and consumption of plastic, which takes decades to decompose, is among the main issues that humanity is now experiencing as the world progresses. In this study, plastics with improved Shore Durometer hardness was looked into as a partial substitution for natural coarse aggregates (NCA) in solving these problems. The LDPE/HDPE plastic coarse aggregates were developed using the best ratio of LDPE and HDPE plastics by melting, molding, and forming into 5mm, 10mm, and 15mm cubes. The gravel substitution volumetric were 2.5%, 5.0%, 7.5%, and 10.0% of the concrete mixture, respectively. When the density of concrete, compression, flexure, and split tensile strength of concrete were examined, a 5% replacement with 10mm size produced the best results. A lighter-weight concrete is evident between the controlled sample and the experimental sample when the best size configuration and percentage replacement leading to a 2.97% difference. In general, the compressive strength and flexural strength of (plastic coarse aggregate) PCA-based specimen is 20.23% and 3.78% higher than that of the controlled specimen, respectively. However, it was found that the split-tensile was lower than the controlled specimen by 2.72%.