Using ordinary Concrete constituents, special admixtures, and other concreting methods, concrete may be produced with high-early intensity. Compared with ordinary concrete, the high-early-strength concrete, often called fast track concrete, achieves its required strength at an early age.

The time the concrete should attain the specified strength ranges from a few hours to several days. The high-early-strength concrete is used for quick shape reuse, prefabricated concrete for rapid part processing, high-speed cast-in-place building, cold-weather building, fast surface maintenance to minimize traffic interruption, and fast-track paving.

How to get concrete that has high early strength?

The high early strength concrete is achieved by using one or a combination of type III Portland Cement, high cement content, low water content to cementitious materials, high freshly mixed concrete, chemical admixtures, additional cementitious materials, autoclave curing, and concrete insulation to retain its hydration heat.

What is cement at high early strength?

Type III or high-strength cement is a form of Portland cement whose reactions are faster than Cement Form I. In three days, the high early strength cement achieves around 70 percent of its 28-day strength.  It is helpful when early stripping of forms is required, or a system needs to be placed into action quickly.

Will autoclave curing improve the early strength of concrete?

The steam of autoclave curing is an important means of high early strength concrete development. The concrete compressive strength achieved in 24 hours under autoclave is equivalent to the concrete compressive strength which can be achieved in 28 days under normal conditions of curing.

How does the acceleration of chemical admixture early on influence concrete?

Accelerating chemical admixture increases concrete hydration rate, as well as early concrete strength development.

What are High-Strength Concrete applications?

The high-strength early concrete used for quick form reuse, precast concrete for fast element production, high-speed cast-in-place construction, cold-weather construction, fast pavement repair to reduce traffic downtime, and fast-track paving.

How to develop concrete with High-Early-Strength?

The strong early intensity can be accomplished by utilizing one or a combination of the techniques below. Choosing the High Early Resistance Production Strategy depending on the period at which the concrete should be provided specified strength:

Type III Portland Cement: Type III or high-strength cement is a type of Portland cement that reacts fast than conventional cement or cement type I. In three days, the high-strength cement hits about seventy percent of its 28-day power. The initial collection of Form III cement concrete is within 45 minutes, and the final set is about 6 hours.

Low Water-cementing Materials Ratio: Reducing the water to cementing material ratio by mass from 0.20 to 0.45 can produce high-resistance concrete. Water to cement content ratio of 0.32 to 0.42 was used for the manufacture of high-early-strength concrete, while the use of 0.20 w / cm would yield very-high-early-strength concrete.

Higher Freshly Mixed Concrete Temperature: Cement hydration rises as temperature decreases for newly poured concrete. Thus, the rise in freshly mixed concrete temperature will improve the production in strength in concrete, and hence achieve high early strength concrete.

Chemical Admixtures: Accelerating admixtures are essential to creating high-early-strength concrete. Calcium chloride, which is standardized by (ASTM D 98), is an example of an accelerating admixture used to produce concrete with high early resistance. The accelerating admixture increases the rate of hydration of concrete and early strength development of concrete.

Supplementary Cementitious Materials: The use of supplementary cementitious material in concrete can produce high-early-strength concrete. The mixture of field granulated blast furnace slag and higher curing temperature contributes to the rise in strong early strength production of concrete.

Steam or Autoclave Curing: The curing of steam or autoclave is an efficient method of making high-resistance concrete. The concrete compressive strength achieved in 24 hours under autoclave is equivalent to the concrete compressive strength, which can be achieved in 28 days under normal conditions of curing.

The concrete under autoclave curing has greater sulfate tolerance, and lower drying shrinkage relative to concrete under standard healing circumstances, in addition to efflorescence removal.

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