Comportamento geotécnico de uma areia reciclada de fresado de revestimentos asfálticos (RAP)

Abstract

Reclaimed Asphalt Pavement (RAP) stands out as a promising alternative in the pursuit of sustainable solutions in engineering, with potential applications beyond asphalt mixtures, particularly in geotechnical works. Several studies have demonstrated that RAP can be used as a fill material, in retaining structures, and in support layers, provided that its geotechnical and environmental properties are properly evaluated. The sand fraction of RAP, composed of its fine portion, can be used as a geotechnical aggregate in various applications, especially in pavement layers and soil improvement. The main objective of this study is to characterize a recycled RAP sand and compare its geotechnical behavior with that of a conventional natural sand of equivalent gradation. The research encompasses the physical, mechanical, and hydraulic characterization of the materials, with emphasis on properties such as shear strength, resilient modulus, permanent deformation, and hydraulic conductivity. The results demonstrated that the recycled RAP sand exhibits a distinct behavior compared to natural sand, requiring greater attention to its compaction state, particularly in applications sensitive to deformability. The recycled RAP sand showed a higher resilient modulus than the natural sand and stabilized deformations throughout cyclic loading. The recycled RAP sand presented lower hydraulic conductivity than the natural sand, due to the presence of asphalt binder and higher porosity. The soil-water retention curves indicated a greater water retention capacity of RAP sand under high suctions. The leaching test revealed chemical stability and the absence of heavy metals at critical levels, confirming the potential of recycled RAP sand for safe use in geotechnical and pavement applications.