Substituição de solo por agregado reciclado no comportamento mecânico de mistura solo-cal

Abstract

In the field of civil engineering, several researches are being conducted to overcome the challenges in the area. One of these difficulties is the inclusion of sustainability in the expansion of civil construction. Among the ways to reconcile these two parts, one of them is the application of construction waste (CW) in the geotechnical area, with the aim of reducing the exploitation of natural resources and increasing the useful life of landfills. Associated with this, when geotechnical projects do not meet the necessary parameters, an alternative is chemical stabilization of the soil, such as the use of lime as a stabilizing agent. Therefore, the present study aims to verify the effect of replacing soil with 25% recycled aggregate on the compaction parameters and mechanical behavior of the mixture stabilized with 8% lime. For this, clayey soil from Campo Mourão, hydrated lime of the type CH-III and CW were used, carrying out tests on real grain mass, granulometry, x-ray fluorescence and compaction and unconfined compressive strength (UCS) for the pure soil, soil-CW and soil-CW-lime mixtures. From the characterization, it was observed that each material has its particular compositional characteristics, such as the soil that has high levels of aluminum and iron. In the CW, quantities of calcium, iron and silicon predominated, which confirmed the presence of mortar and ceramic material in its composition. In terms of compaction, it was clear that the inclusion of 25% CW in the mixture resulted in an increase in the maximum dry mass and a decrease in the optimum moisture content, which leads to the understanding that the workability of the soil in the mixture is filling voids. The inclusion of lime had an opposite effect when compared to the soil-CW mixture, as the maximum specific dry mass decreased and the optimum moisture content increased. As for the UCS results, similar results were observed between soil and soil-CW, indicating replacement without compromising mechanical behavior. When adding lime, there was an increase in this parameter, which occurred throughout the curing period.