Determinação da quantidade de co₂ absorvida em concretos com incorporação de pó de vidro

Abstract

The construction industry plays a fundamental role in the Brazilian economy, but it is also responsible for the high consumption of natural resources, energy, and significant CO₂ emissions. Additionally, it generates a large amount of solid waste, contributing to negative environmental impacts. In light of this, it becomes essential to adopt strategies that minimize these effects, such as the reuse of waste, increasingly valued as alternative sources of raw materials that can be improved. It is worth noting that cement, indispensable in construction projects, releases CO₂ during its production. However, cementitious materials have the ability to capture this gas over time through the carbonation process. Thus, the present work aims to quantify the CO₂ absorption in concretes with 20% cement replacement by glass powder, due to carbonation, through thermogravimetric analysis. Furthermore, carbonation depth was measured by spraying a pH indicator on samples subjected to natural carbonation, and the compressive strength of the concretes was tested. The concrete with 20% glass powder reached the greatest carbonation depth in the shortest time, with 9.37 mm in 28 days. Regarding compressive strength, both the reference concrete and the one with glass powder showed similar results, with the mix incorporating glass powder achieving 153.20% of the minimum requirement of NBR 6136 at 28 days. Thermogravimetric analysis revealed that the reference concrete captured 48.39 Kg.CO₂/m³, absorbing around 60.88% of the CO₂ emissions, while the mix with glass powder absorbed up to 61.77%. These results indicate that the incorporation of glass powder is an effective alternative for reducing CO₂ emissions, contributing to the mitigation of the environmental impacts of the construction industry.