High Early Strength Concrete

High Early Strength Concrete

High early strength means the compressive strength of the concrete in the first 24 hours after production.

High early strength concrete for precast structures

High early strength is often very important for precast structures.

Higher early strength means

• Earlier striking
• Faster turnaround of the formwork
• Earlier handling of the precast structures
• More economic use of cement
• Less heat energy, etc.

High early strength ready mixed concrete

Diametrically opposed requirements are often involved here. On the one hand, a long working time is often required (for handling/installation), but on the other hand, early strength after 6 hours is required. These requirements can only be met by using modern superplasticizers, hardening accelerators and specially adapted mixes.

Uses of high early strength ready mixed concrete

For all ready mixed concrete applications where high initial strength is required, including:

• Short striking times, especially in winter
• Early load bearing situations (traffic areas/tunnel invert concrete)
• Slipforming
• Early finishing (e.g. granolithic concrete during the winter)
• Reduced winter protection measures
• Parameters influencing high early strength concrete

The strength development and consistence depend on the following parameters:

• Cement type and content
• Concrete, ambient and substrate temperatures
• Water/cement ratio
• Element dimensions
• Curing
• Aggregate composition
• Concrete admixtures