Evaluation of Mechanical Properties with the Use of EPS Polymer for the Preparation of Sustainable Composite Based on Concrete

The civil construction area is one of the activities with the highest consumption of raw materials, presenting a large generation of waste. The use of EPS polymer (expanded polystyrene), in addition to being technological, has a low environmental impact by reducing the use of traditional concrete inputs, in addition to being 100% recyclable, cost-effective. The study enabled the elaboration of the composite based on concrete with different contents of recycled expanded polystyrene (EPS) added (0.20; 0.10 and 0.05%, in % weight/weight). The use of this material allowed the partial replacement of standard sand in the composite aggregate, obtaining an environmentally sustainable material, with low specific mass, thermal resistance with insulating, hydrophobic properties that allow low water absorption, with a low impact manufacturing process. This addition of EPS to the fresh concrete mixture showed a reduction in water penetration, making the construction material more hydrophobic, minimizing infiltration problems, reducing the physical process of absorption. The specimens for the concentration of 0.10% (weight/weight) showed better axial mechanical performance, with an average of 11.4 kgf, 52% in gain of reinforcement effect, in relation to the concentration of 0.20% (weight/weight). For this concentration of 0.20 (weight/weight), the EPS beads obtained greater homogeneity in the dispersion in the cementitious matrix, promoting better impact absorption during mechanical efforts. The absorption test was carried out for 10 and 20 minutes, and with that the percentage of water absorbed for each composite was verified. The specimens prepared with higher contents of styrofoam (0.20% and 0.10%), with 0.98 and 1.29%, respectively, of absorbed water, showed a more hydrophobic character due to the higher percentage of presence of pearls. EPS, making the material less permeable to water. The absorption results were quite satisfactory, showing values ​​below 20%, as recommended in the NBR 8491 standard.