Sustainable Use of Recycled Concrete Aggregate for Soil Improvement

Abstract One of the most significant issues that engineers face in geotechnical engineering projects is weak and problematic soils. Therefore, there is always a necessity to develop sustainable methods to improve properties of weak soils in order to enhance the performance of the structures built upon them. The aim of this research is to improve the characteristics of loose, poorly graded sand soil using recycled concrete aggregate (RCA). RCA with various grain-size distributions was utilized as a partial replacement for the soil. The replacement contents were 5%, 10%, 15%, and 20% by the weight of the treated soils. The compaction and bearing resistance characteristics of the treated soils were investigated. The results showed that the inclusion of RCA significantly improves engineering characteristics of the soil in terms of California bearing ratio (CBR) and maximum dry density (MDD). Additionally, it was found the 15% represents optimum RCA content that can be utilized for stabilizing weak subgrade soils. Consequently, the study’s findings support the value of including RCA in field application stabilization plans for geotechnical and road engineers.