Application of demolition wastes mixed with crushed glass and crumb rubber in pavement base/subbase

Recycling and the reuse of waste materials as a replacement for the traditional construction materials in building and civil infrastructure is a significant step to reduce greenhouse gas emissions and the use of natural resources. However, most studies have focused on the behaviour of construction and demolition (C&D) aggregates mixed with a single waste material. To the best of authors' knowledge, there is no previously published work on using C&D aggregates containing both crushed waste glass and crumb rubber for road base/subbase applications. In this study, a series of experiments were conducted to assess the dynamic behaviour of recycled concrete aggregate (RCA) and waste crushed rock (CR) blended with crumb rubber (R) and crushed glass (CG). Testing included permanent deformation, resilient modulus, Clegg impact hammer, dynamic lightweight cone penetration, aggregate crushing value, and Los Angeles Abrasion. The cyclic triaxial test is the most reliable test for the evaluation of the behaviour of unbound granular pavement materials under dynamic wheel loads. However, the test procedures are very time-consuming, complicated, and expensive. Therefore, it is highly desirable to have a simple and straightforward method to evaluate the dynamic behaviour of unbound waste aggregates. For the first time, a simple and quick method was proposed in this study for estimating the permanent deformation and resilient modulus properties of three combined waste aggregates by using two simple dynamic tests (i.e., Clegg impact hammer test and dynamic lightweight cone penetration test). The analytical results indicate that a strong correlation exists between the results of the cyclic triaxial test and simple-procedure dynamic properties.