Impact of crushing shape and geopolymerization on reclaimed concrete aggregate for recycling in the flexible pavement: an enhanced circular economy solution
Omer Sattar, Usama Khalid, Zia ur Rehman, Wasim Irshad Kayani, Abbas Haider
Abstract
This study evaluates the quality and mechanical performance of various shapes of reclaimed concrete aggregates (RCAs), including elongated, cone-shaped, angular, and ordinary mix, in comparison to fresh aggregates (FAs). The RCAs are treated with fly ash-based geopolymer, and the effects of various percentages of geopolymer content on the geotechnical properties of the modified RCAs are investigated. The study finds that the angular shape of an RCA exhibits more strength than other shapes, and the use of fly ash-based geopolymer significantly improves the mechanical characteristics of the modified RCAs by up to 10%. The research also shows that the use of fly ash-based geopolymer-treated RCAs in the subbase layer of flexible pavements can lead to a reduction in the required thickness of the base layer, resulting in significant cost savings and curtailment of CO2 emission compared to the use of FAs.