Performance and Limitations of Limestone Calcined Clay Cement Concrete for Pavement Applications Under Lab and Field Conditions

Although limestone calcined clay cement (LC ³ ) has been increasingly studied in laboratories, commercial LC ³ is just emerging in the United States, and field investigations remain insufficient to support widespread adoption. This study evaluated LC ³ concrete performance under lab and field conditions. Fresh properties (slump and air content), mechanical strength (compressive and flexural), and durability characteristics (surface resistivity, shrinkage, and freeze–thaw resistance) were measured. Field observations and binder production cost and environmental impact assessments were also conducted. The results indicated that although the LC ³ mixes exhibited higher water demand and slightly lower strength at an early age (before 7 days), the LC ³ concrete achieved compressive and flexural strength exceeding 3,000 psi (7 days) and 500 psi (3 days), meeting traffic-opening requirements. Lab tests demonstrated lower total free shrinkage after 35 days, higher surface resistivity, and comparable freeze–thaw resistance when compared with the control mix (no calcined clay). Although small and fine surface cracks were observed, LC ³ concrete maintained its integrity in ring shrinkage tests. Field observations showed that the LC ³ concrete maintained a desirable appearance after 1 year of winter exposure, suggesting its suitability for pavement applications. Production-stage analysis revealed that the LC ³ mix reduced the environmental impact by about 40.3% and energy consumption by 33.9%, with comparable costs when compared with ordinary Portland cement concrete. Despite some limitations (e.g., high water demand, slow strength development, and sensitivity to curing), this study demonstrates the practical viability and environmental benefits of LC ³ concrete for sustainable pavements, offering a useful reference for future use.