Experimental and Analytical Performance of Recycled Aggregates Produced by Customized Chemical-Mechanical Treatment

Abstract

The purpose of this study is to evaluate the experimental and analytical performance of untreated recycled aggregates (URA), chemically treated recycled aggregates (ARA), and customized chemical-mechanically processed recycled aggregates (A_mRA). The compressive strength, split tensile strength, flexural strength, fracture energy, and modulus of elasticity of concrete consisting of A_mRA (A_mRC) are greater than those composed by URA (URC) by 33.88%, 5.87%, 55.07%, 28.84%, and 50.80%, and those of ARA (ARC) by 10.89%, 21.41%, 29.44%, 55.33%, and 34.48%, respectively. A_mRC has abrasion resistance around 52.03% and 43.07% higher than URC and ARC. Chemical treatment reduces porosity and microcracks in mortar adhered to aggregate. As a result of the customized mechanical treatment, the surface characteristics are highly uniform and dense. The high-quality surface texture, reduced porosity, and microcracks in the mortar adhering to the A_mRA significantly strengthen interfacial transitions zones. Thus, A_mRC achieves physical, mechanical, and durability properties close to or superior to natural aggregate (NA) concrete (NAC). Moreover, there is a strong correlation between compressive strength and split tensile strength, flexural strength, fracture energy, and modulus of elasticity of A_mRC with URC and ARC. The most interesting observation of the present research is the equivalency in sorptivity of A_mRC and NAC. The present study uses the URA produced by crushing concrete cubes in the laboratory.