An important issue associated with wintertime construction is the ability to mix fresh concrete without it freezing. To obtain the required compressive strength, warm curing or heat curing is often performed at the construction site. However, both these methods are difficult to manage, incur the risk of fire, and have low energy efficiency, with excessive heat loss to the surrounding environment. To overcome these problems, here we evaluate the performance of concrete as a function of the concentrations of high early strength cement and accelerator for protection against freezing. Our aim is to develop a concrete with a compressive strength of 5MPa within one day of aging to prevent early frost damage. We achieve this compressive strength development when the amounts of high early strength cement and accelerator exceed 15%. Increasing the amount of accelerator increases the early compressive strength by shortening the setting time and enhancing Ca(OH)2 formation. Thus, early frost damage could be prevented in low-temperature concrete construction work without warm curing or heat curing when the waterto- binder ratio is reduced. The use of high early strength cement and an accelerator for freeze protection is optimized.

Keywords: Freeze protection, Frost damage, High early strength cement, Accelerator, Winter concreting.