Estudo da viabilidade de substituição parcial do agregado miúdo natural por resíduo de pet na fabricação de concreto leve

Abstract

Civil construction is a sector that consumes a significant amount of natural resources. In this context, it’s necessary to search for alternative materials that make use of the reuse of waste in your production. This work aims the production of a new material that adds the incorporation of the PET residue in the production of lightweight concrete, that is, the production of a concrete that reuses materials, has a low density and that provides satisfactory mechanical and thermal properties. After the trace study, developed three lightweight concretes with expanded clay: reference lightweight concrete containing 100% natural sand, lightweight concrete with partial replacement of 15% of the natural aggregate by recycled aggregate PET and lightweight concrete with partial replacement of 30%. Some physical properties (density, water absorption and void index) and mechanical properties (compressive strength and tensile strength in flexion) were studied. The lightweight concretes reached compressive strength higher than 17 MPa at 28 days, being classified structural lightweight concretes, according to the NBR NM 35 (ABNT, 1995). Through an statistical analysis, mathematically the lightweight concretes have the same compressive strength, however, the values of tensile strength in flexion showed an increase for the concrete with 15% PET replacement. Also was evaluated the thermal conductivity, witch showed satisfactory results when compared to the national standard of thermal performance (NBR 15220/2005). The substitutions showed no loss of thermal performance in relation to the reference concrete.