Performance Evaluation of Reclaimed Asphalt Pavement (RAP) Incorporated Concrete for Rigid Pavements

Abstract

Abstract: The production of Reclaimed Asphalt Pavement (RAP) has seen a recent increase, and Pakistan's road network spans almost 100,000 kilometers, with almost 30% of RAP able to be produced from it. This study aimed to explore the use of RAP as an aggregate in rigid pavements. Virgin coarse aggregate (VCA) was partially or completely replaced with RAP at ratios of 0, 25, 50, 75, and 100%. A mix design was carried out to achieve 4000psi, and fresh concrete specimens were cast and tested for slump, temperature, and unit weight. After 28 days of curing, some of the hardened concrete specimens were tested for compression and tensile strength using a Universal Testing Machine (UTM) machine, while flexural tests were conducted on beams. The modulus of adaptability was calculated using UCAM programming with the help of a data logger. The results indicated that compressive, flexural, and splitting tensile strength reduced with an increase in RAP content. However, the modulus of elasticity plots shows that while the stiffness decreased with an increase in RAP content, ductility shows a slight improvement. Based on the findings, replacing up to 25% of VCA with RAP was considered the best permissible replacement in rigid pavement, offering maximum performance. Additionally, a cost analysis of RAP showed a 71% cost saving in VCA and 3% overall section cost saving by replacing just 25% of RAP.