In- Situ CBR Assessment of Subgrade in Flexible Pavement Mixed with Waste Tyre Scrap Material

Abstract

This study deals with strength enhancement of flexible pavement subgrade using waste tyre scrap. It primarily evaluates the in-situ California Bearing Ratio (CBR) of subgrade clayey soil blended with tyre scrap. The study employs a mix of laboratory tests, including modified proctor and CBR tests, alongside the Dynamic Cone Penetration Test (DCPT) as a field method. The results show a marked improvement in the in-situ strength of the subgrade when tyre scrap is incorporated. Specifically, CBR values exhibited a substantial increase, rising from 3.82 to 9.21 with a 10% inclusion of tyre scrap of size 15mm×15mm, in the existing subgrade. This study underscores the efficacy of using tyre scrap as a sustainable and efficient material for pavement improvement. It not only presents a viable approach to managing waste tyre disposal but also contributes to the increased strength of pavement structures.