O crescimento de obras no setor da construção civil faz com que aumente o uso de agregados naturais. Este grande uso, ocasiona em uma escassez em várias regiões, principalmente nas regiões de grande área ocupada, fazendo com que seja extraído o material natural em locais distantes do ponto de aplicação. Vários materiais alternativos como, resíduos de construção e demolição (RCD), resíduos de pedreira e fosfogesso, vêm sendo estudado a fim de avaliar o comportamento do solo com adições em várias proporções de material. O presente trabalho tem o intuito de apresentar uma discussão baseada em pesquisas já realizadas em grandes centros urbanos do Brasil, levando-se em conta a aplicação do material em camadas de pavimentação. São analisados os ensaios de caracterização do material e estudos de pistas experimentais.

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Despite the fact that sewage systems are highly efficient in removing organic matter, pathogens and nutrients, sewage treatment plants have experienced challenges related to the management of the generation of solid waste. The major concern with the generated sewage sludge (biosolids) is that it presents in its composition elements that on contact with the ground and groundwater may compromise their quality, contaminating them. In this context, there have been studies aimed at verifying the potential contamination of sewage sludge, as well as studies on the mechanical behaviour of the soil under the action of this disposal process. The objective of this research was to investigate the transport of sewage sludge contaminants in nature state, and the monospecies transport of nickel and chromium solutions and further to verify how the sludge constituents can change the soil strength characteristics. This survey conducted geotechnical soil characterization tests, geo-environmental tests (diffusion and sorption) in the laboratory, and diffusion in the field, and also soil strength tests (consolidation and direct shear and simple compression). Results indicate that the soil under consideration is a typical laterite soil from the DF, and its coefficient of permeability allows the soil to be used as a compacted liner. Contaminant transport results showed that the contaminant in nature state suffers from dispersion, due to the intense biological activity and increased capacity of the soil cation exchange. However, results of the synthetic monospecies solutions indicate the tendency for this type of test, the concentration decreases as a function of time. The strength results demonstrated that the sewage sludge contaminants have characteristics that may change the cementation connections. The results in simulating successive applications of sewage sludge on the soil (five applications), were the ones the showed lower cohesion values and higher strains in the consolidation curve. On the other hand, the soil contaminated with sewage sludge and lime, was the one that showed the lowest cohesion values. Thus, it can be seen that the constituents of the sewage sludge, can migrate to the soil contaminating it, and that its constituents may decrease its strength.

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