Properties of Concrete Influenced by Plastic Materials

Little research is reported on the properties of Portland cement concrete (PCC) mixtures comprising plastic waste materials. Therefore, this novel study was initiated to evaluate the effects of plastic waste materials on different properties of PCC. Plastic boxes and containers made of polypropylene were cut, grinded, pulverized, and incorporated into PCC mixtures. Sand was partially replaced by plastic waste materials with 0%, 5%, 10%, 15%, and 20% volume ratios. Experiments were conducted using PCC cylinders and prisms to evaluate several unique properties of PCC containing plastic waste. Innovative interactions and contributions of several PCC properties including workability, air content, density, water absorption, mechanical properties, rapid chloride ion penetration, and freeze–thaw deterioration are investigated. The new experimental data indicated that the workability and density of PCC decreased with increasing plastic waste replacement levels. The maximum decreases in workability and density were 23% and 6.2% for the PCC with 20% plastic replacement, respectively. On the other hand, our research has shown that air content and water absorption of PCC increases with increasing plastic waste amount. The maximum increase in air content and water absorption were 78% and 29% for the PCC with 20% plastic waste. This study also shows that the mechanical properties of PCC (e.g., compressive and splitting strengths) after 7 and 28 days of moist curing decreased with increasing plastic waste content. Another new finding is that the rapid chloride permeability of PCC increased and the freeze–thaw durability of PCC decreased with an increase in plastic waste amount. One of the most critical discoveries of this experimental study is that plastic waste increases the durability of PCC, i.e., durability factor of PCC with 20% plastic waste was 9.3% compared to 28.5% for the control PCC without plastic waste materials.