UCLA

Accelerated pavement rehabilitation under cold weather conditions is traditionally constrained by the slow early-age strength development of conventional Portland cement systems. This limitation directly impacts the ability of agencies to reopen critical infrastructure within short construction windows.

This paper demonstrates that Belitic Calcium Sulfoaluminate (BCSA) cement-based concrete—a binder system entirely free of Portland cement phases (Alite C₃S and Tricalciumaluminate C₃A)—can reliably achieve compressive strengths on the order of 3,800–4,800 psi (26–33 MPa) within 4 hours across a range of placement temperatures from approximately 30°F to 70°F, enabling rapid return-to-service even under adverse environmental conditions. Results are drawn from three field projects involving airfield pavements, highway reconstruction, and structural bridge elements, executed using both ready-mix and volumetric delivery systems.

Unlike many calcium sulfoaluminate systems that rely on partial replacement or hybridization with Portland cement, the BCSA binder used in this study derives its performance entirely from its intrinsic phase assemblage, dominated by ye’elimite and belite.

Beyond documenting case study performance, this work proposes a performance-based framework for rapid concrete construction centered on strength at time-of-opening as the governing design parameter. The results show that early-age performance is primarily controlled by the interaction of binder chemistry, thermal management, and construction logistics, rather than ambient temperature alone.

The findings challenge conventional assumptions regarding cold-weather concreting limitations and demonstrate that predictable reopening within a 4-hour window is achievable near freezing conditions when appropriate material systems and field controls are implemented. This supports a shift toward performance-based specifications for rapid infrastructure rehabilitation, where time-to-strength—not prescriptive composition—defines success.