ABSTRACT
The American Concrete Institute’s (ACI) method of proportioning concrete has a different approach altogether compared to any other method known worldwide. The ACI method stands out from the other methods of mix proportioning due to the methodology of aggregate proportioning. In other systems, aggregates are proportioned either to fit the particle-size distribution within stipulated limits or based on the zone of sand. Whereas, in the ACI method, a loose bulk density of coarse aggregates and fineness modulus of fine aggregates help in deciding the proportions. This method is close to particle packing as compared to other methods, which will become relevant in explanations given in this chapter. Other proportioning methods are based on the assumption that a particular size distribution of particular or the one closer to the ideal zone will have least voids or optimum performance. The assumption, though, has been found to be a fallacy, and aggregate shape is now found to be not only as important but also more important than particle-size distribution. ACI aggregate proportioning involves multiplication of certain factors to the loose bulk density of aggregates, which in turn is affected by the void content between the aggregates.
How is ACI method of concrete proportioning different from other methods?
What is ACI’s aggregate-proportioning method for concrete proportioning?
What effect does air content have on concrete proportioning?
