Effectiveness of Various Curing Techniques in Concrete

Abstract

Appropriate curing of concrete is of vital importance in development of desired material properties in concrete namely compressive strength and durability based on uniform dense microstructure. Improper and intermittent curing is considered as one of the major reasons for concrete failures as evident in the form of cracks that consequently lead to low compressive strength and durability issues in concrete structures. Conventional concrete practices require cost efficient and effective curing methods be followed to achieve strength and durability with available materials at site. An experimental program was designed to study the behavior of concrete under various conventional and modern curing techniques. One hundred and eighty concrete cylinder specimens were investigated with different curing techniques namely, water curing, burlap curing, liquid membrane-forming compound curing, combinations of admixture and liquid membrane-forming compound curing, admixture and burlap curing compared to air curing. In addition, new internal curing methods namely light weight aggregate, super absorbent polymers, and shrinkage reducing admixtures were investigated to quantify their effects on curing of concrete. Comparison of microstructure development with scanning electron microscopy (SEM); quantitative analysis with energy dispersive spectroscopy (EDS) analyses and compressive strength at different ages were conducted to monitor the effect of various curing methods on microstructure and strength in concrete. The results indicate that development of microstructure differs based on variation in chemical composition that occurs during hydration processes from various curing regimes. The results exhibit higher attainment of compressive strength in case of wet burlap curing and immersed curing than rest of the compared techniques. Internal curing methods of light weight aggregates and super absorbent polymers were found to be excellent in reducing autogenous shrinkage in concrete due to uniform distribution of curing water within the mix; consequently leading to uniform microstructure and superior concrete for construction purpose. This work is helpful in establishing the best curing techniques to obtain higher compressive strength and durability in concrete. The results are also useful in determining appropriate curing technique to suit specific field conditions.