This mix has the following main properties:
High strength.
High workability.
High durability.
Ease of placement.
Compaction without segregation.
Early age strength.
Long-term mechanical properties.
Permeability.
Density.
Heat of hydration.
Toughness.
Volume stability.
Long life in severe environments.
Preparation
High strength concrete mix can be prepared with careful selection of ingredients and optimization of mix design.
High workability is attained by super plasticizers, they lower the water cement ratio to 0.25 which is the amount required only for hydration process.
High durability is attributed to fly ash and silica fume which modify the e mineralogy of the cement; it enhances the compatibility of ingredients in concrete mass and reduces the CH amount. Fly ash also causes ball bearing effect increasing workability.
The admixtures are 20-25% fly ash of partial replacement of cement and rest 70% is Ordinary Portland Cement.
As it is not usually durable against freezing and thawing so air entrained agents can also be utilized.
Properties of high performance concrete mix
Strength of high performance concrete ranges from 10000 psi – 15000 psi
Water cement ratio can be reduced to 0.25