Mix design of high strength concrete is influenced by properties of cement,sand, aggregates and water-cement ratio have compressive strength above 40 MPa.

To achieve high strength it is necessary to use lowest possible water cement ratio which invariable affect the workability of the mix and necessitates the use of vibration technique for proper compaction.

In the present state of art a concrete with a desired 28days compressive strength up to 70MPa can be made the suitable proportion the ingredient using normal vibration technique for compaction the concrete mix.

Mix design of high strength concrete procedure.

1) The mean design strength is obtain by applying suitable control factor to the specified minimum strength.

2) For a given time of cement and aggregate used the reference number corresponding to design strength at particular age in interpolated from fig 1

3) Water cement ratio to achieve the workability and corresponding the reference number is obtain for aggregate with maximum size of 20mm and 10mm.

4) The aggregate cement ratio to give the desired workability with the known water cement ratio is obtain by absolute volume method.

5) Batch quantities are work out after adjustment for moisture content in the aggregate.