Blocos de concreto para vedação termicamente eficientes com resíduo de poliestireno extrudado (xps): Desenvolvimento e transferência tecnológica

Abstract

The increasing generation of plastic waste and the need for more thermally and environmentally efficient construction solutions have driven research on the incorporation of polymeric materials into cementitious matrices. In this context, this study aimed to develop and evaluate concrete masonry blocks with partial volumetric replacement of coarse aggregate by extruded polystyrene (XPS) waste, analyzing their physical, mechanical, and thermal performance, as well as their potential for social application. Initially, a pilot phase was conducted with different volumetric replacement levels of coarse aggregate by XPS (25%, 30%, 35%, and 40%), in addition to a reference mixture without waste incorporation. The produced concretes were evaluated in terms of apparent density, oven-dry density, compressive strength, and ultrasonic pulse velocity. Based on the obtained results, the 35% replacement level was selected for the full-scale production phase. In the subsequent stage, concrete blocks were produced and subjected to compressive strength testing and thermal performance evaluation. Thermal analysis was carried out through experimental tests with temperature monitoring over time and estimation of apparent thermal conductivity, comparing the 35% XPS mixture with the reference mixture. Complementary thermal properties, such as specific heat, were also determined to improve the understanding of the material's thermal behavior. The results indicated a significant reduction in density with XPS incorporation, demonstrating increased material lightness. A decrease in thermal conductivity compared to conventional concrete was also observed, indicating improved thermal performance while maintaining compressive strength compatible with non-load-bearing masonry requirements, according to applicable standards. Finally, technology transfer actions were conducted within a local community, including training and demonstration of the production process. These activities indicated technical compatibility of the constructive method with the community context and potential for social application, although continuous production still depends on operational structuring and organizational development. Overall, the study demonstrates that the use of XPS waste in the production of concrete masonry blocks constitutes a technically feasible alternative, thermally more efficient than conventional material, and with potential environmental and social contributions.