Road no 4 method

This method of designing concrete mix proportion is mainly based on the extensive laboratory and field experiment carried out the road research laboratory UK.

It was first publish in road note no 4 during 1950.

They have establish relationship between various properties of concrete and various parameter. A series of standard grading curve have been establish to give grading limit for all in aggregate graded down from 20mm and 40mm.

The procedure of mix design by road note no 4 is also called grading curve method.

This method of mix design was popular and widely use upto 1970s all over the word. Most of our concrete road and air field pavement where design by this method.

ACI method of mix design (American concrete institute)

ACI method of concrete mix design is based on the estimated weight of the concrete per unit volume. This method takes into consideration the requirements for consistency, workability, strength and durability. This article presents ACI method of concrete mix design.

ACI Method of Concrete Mix Design

Required Data:

Before starting concrete mix design, basic information on raw materials shall be prepared which include:

1) Sieve analyses of fine and coarse aggregates.

2) Unit weight (dry rodded density) of coarse aggregate.

3) Bulk specific gravities and absorptions or moisture content of aggregates.

4) Mixing-water requirements of concrete developed from experience with available aggregates.

5) Specific gravities of Portland cement and other cementitious materials, if used.

6) Relationships between strength and water-cement ratio or ratio of water-to-cement plus other cementitious materials, for available combinations of cements, other cementitious materials if considered, and aggregates.