Frequently Asked Questions About Concrete Early Strength?

Frequently Asked Questions about Concrete Early Strength?

How do you get concrete in early strength?
High-early-strength concrete (HESC) is a type of concrete that attains the required strength within a short time. This is achieved by using ordinary concrete constituents and special admixtures.

The strength gain of concrete is influenced by the initial setting time, hydration rate, and activation energy. In order to achieve the desired strength gain in a short time, it is important to produce concrete that has high curing temperature and a rapid hydration rate.

A mathematical model for the rate of relative increase in concrete compressive strength with respect to its limiting compressive strength (S u in MPa) was suggested by Bernhardt (1956). This equation can be expressed as: Eq. (4)where, k is the rate constant of concrete compressive strength development; r is the reaction coefficient; and s is the initial hydration rate.

Reaction Coefficient:

In order to accelerate the hydration rate, a number of chemical admixtures are available that can be added to the concrete mix. Some of these admixtures are calcium chloride, which is standardized by (ASTM D 98); sodium carbonate; and urea.

Water-to-Cementing Material Ratio:

Lowering the water to cementing material ratio can help produce higher-early-strength concrete. This can be done by reducing the water-to-cementing material ratio to about 0.20 by mass.

Freshly Mixed Concrete Temperature:

The hydration of cement is increased as the freshly mixed concrete temperature decreases, so this can lead to a faster hydration rate and early strength gain in concrete.