Curing concrete serves two primary purposes: to moderate the rate of heat loss from freshly poured concrete to the environment, minimizing temperature differentials within the concrete’s cross-section, and to curb water evaporation, preventing premature drying.
Several curing methods exist, each with its own advantages and drawbacks:
Ponding: This technique involves creating a pond of water on the concrete surface, ensuring ample moisture for curing. However, it is highly susceptible to weather conditions, particularly cold winds, which can accelerate evaporation. Additionally, the large volume of water used necessitates proper disposal after curing, posing logistical challenges.
Polythene Sheet: This method relies on preventing air flow over the concrete, thereby halting evaporation. Polythene sheets create a barrier against moisture loss, but they are vulnerable to strong winds, which can compromise their effectiveness. Furthermore, this method does not replenish water lost through self-desiccation, a process where internal moisture is consumed during cement hydration.
In conclusion, choosing the optimal curing method involves balancing effectiveness with practicality. Ponding, while providing excellent moisture retention, requires careful environmental management. Polythene sheets offer a simpler solution but lack robustness against wind and cannot compensate for self-desiccation. A thorough understanding of these methods and their limitations is essential for ensuring successful concrete curing.