Análise do reaproveitamento do pó proveniente da retificação de corpos de prova de concreto como fino em novos concretos

Abstract

This paper deals with the use of concrete waste in the production of recycled concrete. It is estimated that the construction industry produces an average amount of 500 kg/inhab.year of waste in Brazil, which generates a considerable negative environmental impact. In parallel, the construction industry consumes approximately 40% of non-renewable natural resources, with concrete being the most used material in this sector. Thus, in order to alleviate the aforementioned issues and contribute to a more sustainable construction industry in the future, this paper analyzed the addition of fines from concrete specimens as raw material in the production of concrete, in proportions of 5%, 10% and 15% in relation to the amount of cement in the reference concrete (without addition of fines). Regarding the approach and procedures of this research, it is characterized as quantitative, qualitative and experimental, since it determined the properties of concrete in its fresh and hardened states through the collection and analysis of data obtained in laboratory tests and performed the comparative analysis of the concretes studied. The results showed that concrete with the addition of fines in the proportions studied presented advantages and disadvantages in relation to the reference concrete. The main advantages were the lower void index, water absorption and real specific mass, while the disadvantages were having presented lower tensile and compressive strength, when compared to the reference concrete. Furthermore, the work found that all the tested additions meet the requirement of a structural concrete, with strength above 20 MPa. However, additional research is necessary to evaluate other properties and important aspects for the future use of this material in construction.