Effectiveness of Rapid-Set CSA Concrete Mixes for Sustainable Pavement Repair

Rapid and sustainable pavement repairs are critical to minimizing road closure times, reducing environmental impacts, and ensuring infrastructure longevity. This study evaluates the effectiveness of rapid-set calcium sulfoaluminate (CSA) concrete mixes compared to traditional concretes (Type III and novel Type X) for pavement repair applications. The research investigates the early-age and long-term mechanical performance of these materials, focusing on compressive strength, tensile strength, flexural strength, shrinkage, and fresh properties. A comprehensive experimental program was conducted using standardized testing methods (ASTM C39, C78, C496, and C157) to provide reliable and comparative data. Results showed that CSA mixes achieved superior early-age strength, exceeding 3,000 psi within four hours and meeting long-term benchmarks of over 5,000 psi at 28 days. Moreover, CSA mixes exhibited significantly lower shrinkage compared to traditional concretes, enhancing dimensional stability. Correlation analyses identified the nuanced influence of water-to-cement ratio, cement content, and polymer additives on shrinkage and strength performance, highlighting the critical role of optimized mix design. These findings demonstrate the potential of CSA-based concretes to address current challenges in pavement repair, including rapid strength development, reduced maintenance frequency, and enhanced sustainability. Practical implications include less traffic disruption, reduced carbon emissions from delays, and resource efficiency, aligning with global sustainability goals. This study provides a pathway for adopting CSA-based materials as a durable, high-performance solution in pavement repair, offering a significant contribution to advancing sustainable construction practices.