Concrete mix design is a three stage process:

Predictive theoretical determination of a formula

* selection of constituents on the basis of local resources

* evaluation of the proportions of the constituents

* optimization of the granular skeleton

Optimization of the mix in the laboratory

* study of cement/additive compatibility

* adjustment of the quantity of paste and additive

* verification of the rheological behaviour of the fresh concrete

* study of the sensitivity of the formula to variations in constituent proportions

* study of the sensitivity of the formula to climatic conditions (temperature)

Validation of the compromise formula

* verification of the rheological behaviour of the fresh concrete

* verification of any additional specifications (pumpability, surface appearance)

* verification of characteristics or specifications with regard to durability.