Aproveitamento de resíduos de polissiloxanos em concreto como substituto do agregado miúdo

Abstract

The study evaluated the use of polysiloxane waste as a replacement for fine aggregate, incorporated into concrete blocks. The production of test specimens and the respective analyses—aggregate particle size distribution, consistency through the slump test, water absorption, tensile strength by diametral compression, and compressive strength of cylindrical specimens—followed current technical standards. The results revealed that the addition of polysiloxane waste significantly affected the concrete properties. A total of 10 control specimens were produced without waste addition, and 10 additional specimens for each volumetric mix were made, with fine aggregates (sand) replaced by polysiloxane in the following percentages: 10%, 20%, 40%, and 52%. The results showed that the partial replacement of conventional fine aggregates with waste can lead to improvements in the workability of the concrete. The slump ranged between 85 and 100 mm for the mixes with 10%, 20%, 40%, and 52% polysiloxane waste addition, showing some variation but still resulting in products suitable for many applications. Water absorption of the specimens was altered with the gradual increase of waste incorporation, although still within acceptable limits (10%) for most applications. However, compressive and tensile strength by diametral compression decreased as the waste incorporation percentage increased, indicating that polysiloxane may alter the internal structure of the concrete. Although the results suggest that incorporating up to 10% of waste may be a viable solution, it is recommended that future studies focus on optimizing the concrete formulation, using additives to improve strength, and conducting long-term economic and durability analyses. It is noteworthy that incorporating polysiloxane waste into concrete can contribute to the circular economy by promoting the reuse of industrial waste.