Pavement Maintenance and Long-Term Pavement Rehabilitation Strategies Using BCSA Cement Concrete

Highway concrete pavement infrastructure built in California during the 1960s-1970s required major rehabilitation by the end of the 1990s. Due to increasing traffic and impact on users caused by long-term closures, the California Department of Transportation (Caltrans) was forced to look for novel strategies to repair highway pavement quickly. Following the successful completion of pilot projects, Caltrans embraced the use of Rapid-Setting Concrete (RSC) with Belitic Calcium Sulfoaluminate (BCSA) cement, setting a precedent subsequently followed by other states. Despite increased use, the durability and long-term performance of RSCs have faced skepticism. This likely stems from a limited understanding of the behavior of such materials over years or decades of service. It is true that some rapid-setting concrete exhibit early cracking that may be due to thermal effects or high shrinkage due to high cement content. In the first section, this paper explores the material properties and characteristics of BCSA, a type of RSC, highlighting its potential to last for decades of service if designed and constructed properly. The second section details projects constructed 5-15 years ago in various climates, under varying traffic volumes and different concrete delivery approaches. Lastly, a forensic analysis conducted on the oldest BCSA highway pavement section in California rehabilitated in 1997 is discussed, showing that BCSA concrete tripled its strength after 23 years in service.