Análise do uso de agregados reciclados de concreto em substituição ao agregado natural e sua influência na resistência à compressão

Abstract

Viewed as one of the largest solid waste generators, a construction company has been looking for alternatives that are increasingly focused on sustainability. In this way, thinking about the reduction of enthusiasts generated by this sector, researches have been developed that deal with the reuse of materials that are discarded, for the generation of new ones. For a production of concrete from recycled aggregates and necessary for a good quality for use, linked to the resistance factor there is also the porosity of the concrete. One of the factors that interfere in the resistance and a relation water / cement, thus being greater the relation water / cement smaller and the resistance. This water consumption is related to the void index of the concrete without hardened state, that is, the more water the concrete consumes, the greater will be an influence without voids index. This can be explained because there is no curing process, incorporated air bubbles are trapped without interior of the mass of the concrete, in general interconnected to each other, facilitating a penetration of aggressive agents and consequently creating fragility points. Recycled concrete and used as aggregates, absorb more water than conventional concrete, making it less resistant, so a whole study is needed on the incorporation of aggregates. The present work aims at replacing the natural aggregate by recycled aggregate in concrete production, thus evaluating its mechanical strength and porosity. The percentages of use were evaluated and presented with concretes produced only with products aggregated without prescription. In view of this, it was sought to improve its incorporation using a particle packing method, which aimed to work with several different particle sizes, to solve the voids with smaller and smaller particles, being possible to reduce its porosity and consequently to increase its resistance.