Which admixtures are used to increase early strength development of concrete?

Accelerating admixtures are specifically designed to enhance the rate of hydration of the cement particles, leading to faster setting times and quicker early strength gain in concrete. These admixtures work by promoting the chemical reactions that take place when water is added to cement, which is crucial in achieving early strength. The ability to reach higher strength levels more rapidly is particularly beneficial in cold weather conditions or when rapid construction schedules are in place, as it allows for earlier formwork removal, quicker project completion, and improved overall efficiency.

In contrast, other types of admixtures serve different purposes, such as water reducing admixtures, which primarily focus on improving workability or reducing water content in a mix without affecting its strength. Retarding admixtures are intended to slow the setting time of concrete, which is useful in preventing cold joints during placements in hot weather, but they do not contribute to early strength development. Corrosion inhibiting admixtures aim to enhance the durability of concrete by preventing the corrosion of steel reinforcement but do not have an impact on the early strength of the mix. Thus, the role of accelerating admixtures is crucial for achieving rapid strength development, making them the appropriate choice for this question.