Retarder

Definition

A retarder is a chemical agent added to concrete to slow the curing process.

Purpose

The purpose of a retarder is to extend the working time of concrete, allowing for more time to place and finish the concrete, especially in hot weather conditions where concrete can set too quickly.

Examples of Use

• In large concrete pours, retarders are used to ensure uniform setting and prevent cold joints.
• Concrete used in hot climates often contains retarders to manage the rapid curing process caused by high temperatures.
• Retarders are used in decorative concrete applications to allow for detailed finishing and patterning.

Related Terms

• Accelerator: A chemical agent added to concrete to speed up the curing process.
• Admixture: A material added to concrete to modify its properties.
• Curing: The process of maintaining adequate moisture, temperature, and time to allow concrete to achieve its desired properties.

Notes

The use of retarders must be carefully controlled to achieve the desired setting time without compromising the strength and durability of the concrete.