Estudo das propriedades físicas e mecânicas de concreto com substituição parcial de agregado natural por agregado reciclado proveniente de RCD

Abstract

The incorporation of construction and demolition waste (C&D waste) as aggregate in concrete requires good understanding of the properties of the materials involved. The purpose of this study was to characterize a specific product of a C&D waste recycling plant, the Usina de Recicláveis Sólidos do Paraná (USIPAR), lo-cated in Almirante Tamandaré, PR. The recycled aggregate was characterized in respect to their particle size and other physical characteristics. The fine fraction of recycled aggregate was chosen to replace the natural aggregate. Other characteristics of this fraction were evaluated, such as pulverulent material content, specific weight and water absorption. Concretes were produced with different substitution rates of natural aggregate by recycled aggregate (0%, 25%, 50%). The properties of the concrete produced were analyzed and was found that increasing the substitution rate of natural aggregate by recycled aggregate reduced the workability, the dry specific weight and saturated specific weight, and modulus of elasticity of concretes, as well as increased absorption and void ratio of concretes. The real specific weight of the concrete was not influenced by the replacement content. In regard to the compression and tension strength, the replacement of natural aggre-gate by recycled aggregate led to a decrease in concrete strength. The concrete with a 50% replacement level obtained a greater compressive strength than the concrete with 25% replacement level, and the same tensile strength as the reference concrete.