While preparing a Design Mix for any Grade, if we have aggregated in two sizes like 10 mm & 20 mm or In fact Sometimes, we do use to have 40 mm aggregate as well.
Is there Any IS Code Provision for the same, What are the references for Combined Grading of aggregates in Code. And how can we use them while Designing a mix?
Following points part of the answer to the question :
There is ACI method available for the same exercise ACI 211.1is the code you can use.
Hope this helps.