Assessment of efficacy of curing practices in concrete

Abstract

Hydration process of cement affects the mechanical and durability characteristics of cementitious mixtures. Owing to its exothermic nature of the reaction, moisture loss is evident from concrete an early age predominantly via the exposed surface. This results in a porous microstructure, development of microcracks and alters the strength gain near the surface even before the structure is loaded. Hence, curing of concrete is adopted. Curing has an active influence up to a depth known as Curing Affected Zone (CAZ) from the top, and its properties depend on the extent of hydration. The moisture content in CAZ governs the characteristics of its microstructure. There are standardized and universally accepted tests to quantitatively as well as qualitatively analyse strengths and durability characteristics of concrete, whilst the assessment of the efficacy of curing practices is still in process. Quality of concrete is commonly assessed based on its mechanical properties, however the concrete that satisfies such properties, may not sustain it over the period of time. It indicates that assessment of curing based on solely mechanical properties might give false indication of quality of concrete. Therefore, the durability properties of concrete must also be used for its quality assessment. This paper comprehensively discusses the assessment of moist and compound curing using test parameters like moisture retention, porosity, permeability, electrical conductivity, sorptivity, abrasion resistance dielectric constant and maturity. The sensitiveness of these properties towards curing media is also reviewed. Finally, the scope for future work based on the critical gaps identified from existing works is also provided to assist further research.