Effect of curing water availability and composition on cement hydration

Abstract

Curing can help concrete reach its full strength and durability potential. The effect of sealing the concrete with plastic or formwork, use of a liquid curing compound, wet curing, and internal curing with saturated lightweight aggregates on the cement degree of hydration (DOH) development with time was examined using isothermal calorimetry. Curing water amount, curing water ionic concentration, and sample thickness were varied. Finally, curing application timing was studied by comparing strength development of concrete cylinders sealed, placed in a moist room after 24 hours sealed, and immersed in a water bath immediately after finishing. Increasing the height of curing water decreased the height of heat of hydration rate peaks. Curing water ionic concentration affected the setting time and heat of hydration rate peak heights. Strength results show delayed curing can result in significant strength loss because of the difficulty for water to penetrate the already-hardened concrete.