What are ingredients called that increase a masonry cement's rate of hydration?

Ingredients that increase a masonry cement's rate of hydration are known as accelerators. These materials enhance the chemical reaction between water and the cement, allowing it to set and gain strength more quickly than it would otherwise. This can be particularly beneficial in cold weather conditions or when a fast-setting time is required for construction. By promoting earlier strength development, accelerators help ensure that work can be completed in a timely manner, thereby increasing efficiency on the job site.

Other types of additives have different functions; for example, retarders slow down the hydration process, which can be useful in hot weather to prevent quick setting. Modifiers are generally used to improve the performance or characteristics of the cement without specifically focusing on the rate of hydration, while plasticizers are intended to improve the workability of the concrete mix without altering its water content drastically. Each of these additives serves a unique purpose in masonry, but accelerators specifically address the need to hasten hydration.