Optimising internal curing parameters for autonomous curing of normal-strength concrete

Autogenous curing, also known as internal curing (IC), has revolutionised the way high-performance concrete (HPC) and high-strength concrete (HSC) are cured. IC improves the service life of concrete by lowering early-age cracking and enhancing durability. However, normal-strength concrete (NSC), the most commonly used type in the industry, is typically cured using conventional methods. Researchers are thus looking at ways to reproduce the positive results found in internally cured HSC/HPC in NSC. Studies have shown that IC is feasible in NSC despite its higher permeability, which results in loss of internal curing water (ICW). However, no comprehensive study has attempted to assess how the type, size and amount of IC agents affect the properties of NSC. The aim of this work was thus to optimise IC parameters for autonomous curing of NSC. The findings of this study support the notion that IC is possible in concrete with a high water/cement ratio and that, compared with lightweight aggregates (LWAs), superabsorbent polymers significantly impacted the durability properties of the NSC. Moreover, varying the size of the IC agent (LWA) had little effect on NSC properties, while increasing the amount of ICW considerably improved the durability properties.