Laboratory study on the performance evaluation of RCA reinforced with geosynthetics for GSB layer application in low volume roads

Abstract

The increasing importance of geosynthetics in civil engineering has been driven by their ability to enhance the performance of infrastructure such as roads, railways, and embankments. Geosynthetic reinforcement improve the pavement performance by providing lateral restraint and tensioned membrane action. For pavement application, geogrids and geocells are widely used. On the other hand, the construction and demolition (C&D) waste generation is increasing owing to rapid urbanization posing significant environmental and logistic challenges. To address the issues related to C&D waste, numerous research has been conducted in the past to characterize recycled concrete aggregate (RCA) for its use in granular layers of pavements through mechanical and additive stabilization techniques. However, these methods have limitations, including the need for specialized equipment, labour-intensive processes, and curing period. Owing to the limited studies on the performance of RCA in conjunction with geosynthetic reinforcement in granular sub-base (GSB) application, this study evaluates the performance of RCA in GSB application with and without geosynthetic reinforcement and compare its performance with conventional aggregates (CA). Prototype pavement sections were constructed under unreinforced (UR), geogrid reinforced (CGG), geocell reinforced (CGC), and combination of geocell & basal geogrid-reinforced (CGG + CGC) conditions. Through repeated load tests, displacement of the pavement section, vertical pressure at the subgrade level, and strain along the reinforcement are monitored. Results showed that RCA performed comparable to CA, supporting its use in GSB application and promoting sustainable practices. Geosynthetic reinforced pavements exhibited reduced plastic displacement by a factor of 0.13 to 0.41 compared to UR sections. The CGG + CGC sections achieved the highest traffic benefit ratio (TBR) of 4.55 with CA and 7.25 with RCA. Additionally, geosynthetic reinforced sections showed reduced residual pressure by 0.14 to 0.39 times compared to UR sections. Strain analysis indicated superior load distribution in CGG + CGC sections over sections with CGC alone. The study concludes that the combined use of RCA and geosynthetics offers a cost-effective, sustainable solution for pavement engineering, promoting extended pavement life and reduced maintenance costs.