Evaluation of recycled coarse aggregate on the mechanical and physical properties of 175 kg/cm² concrete

Abstract

The growth of the construction industry has led to a significant increase in construction and demolition waste, necessitating sustainable alternatives for its management. This study evaluates the reuse of recycled coarse aggregate derived from the demolition of rigid pavements as coarse aggregate in new concrete structures, aiming to reduce waste and contribute to the sector's sustainability. The research is applied and explanatory, as it addresses the use of recycled concrete as coarse aggregate and analyzes its causal relationship with the physical and mechanical properties of concrete, using an experimental design with a quantitative approach. Five substitution percentages of natural coarse aggregate with recycled aggregate were analyzed: 0%, 10%, 20%, 30%, and 40%. Recycled coarse aggregate (RCA) significantly impacts the properties of 175 kg/cm² concrete, reducing its compressive strength by up to 11.48% and its workability from 9.53 cm to 1.27 cm as RCA increases from 0% to 40%. Beyond 30%, these properties fall outside acceptable standards. However, substitution proportions of up to 30% maintain acceptable properties, supporting sustainable practices with proper quality control. Higher percentages, however, significantly compromise structural performance and workability, limiting their application in projects requiring compliance with regulations. The use of recycled coarse aggregate is recommended in designs with compressive strength of f’c = 175 kg/cm² for substitution percentages of 30% or less.