Melhoramento de um Solo Expansivo com Resíduo de Construção e Demolição

Improvement of an Expansive Soil with Construction and Demolition Residue

Abstract

Expansive soils increase in volume when subjected to an increase in moisture and contract when they lose moisture. Construction carried out on expansive soils can present various pathological manifestations.  This article presents a study on the improvement of an expansive soil located in Santa Maria da Boa Vista-PE, mixed with 10%, 20% and 30% construction and demolition waste (CDW), in relation to the mass of the dry sample. Physical and mechanical characterization tests were carried out on the soil and mixtures, chemical and microstructural tests on the soil, and physical and chemical characterization of the CDW. The soil showed 8.58% "free" expansion, making it a soil with a high degree of expansion and the possibility of serious damage due to its expansion stress (81.25 kPa by the Constant Volume Method). The mixture with 30% CDW reduced the expansion stress to 20 kPa and the "free" expansion to 0.90%. Thus, the addition of CDW to the soil proved to be efficient in stabilizing expansion.