Effect of Different Cracking Mitigation Measures on High Early–Strength Concrete Performance

Early-age cracking may occur in high early–strength (HES) concrete repair slabs used for full-depth repairs in jointed plain concrete pavements (JPCPs) due to the early-age volume changes. HES concrete utilizes high cement content and low water-cement (w/c) ratios, which can cause concrete to experience high temperature rise and increased autogenous shrinkage, and therefore higher cracking potential. Field and laboratory experiments were performed to systematically assess several cracking mitigating strategies, namely paste content reduction and addition of lightweight aggregate (LWA), shrinkage-reducing admixture (SRA), and fiber. It was observed that the initial stress development in most of the field slabs was affected by the moisture migration to the base. The paste-reduced mixture was identified as a potential mix for HES repair slabs. Although inclusion of LWA, SRA, and fiber controlled the moisture loss to the base and subsequently decreased the initially induced tensile stresses, only prewetted LWA demonstrated promising results in minimizing cracking risks.