If you found this informative, please don’t forget to share it. I hope now you understood the concrete mix ratio and proportioning of concrete. The amount of fine aggregate should be such as to fill the voids. The minimum void method is based on the principle that the concrete with the minimum voids is the densest and most durable. Pm = Fineness modulus of mix aggregate Minimum voids Method
Pc = Fineness modulus of coarse aggregate
The relation gives the proportion of the amount of fine aggregate (W) to be mixed with one part of the coarse aggregate. The values of fineness modulus more than this value make the concrete harsh, while a lesser value leads to an uneconomical mix. The coarser the aggregate higher will be the fineness modulus while finer the aggregate lower will be the fineness modulus.įrom various experiments, specific values of fine, coarse, and mixed aggregate prove to be more economical than others, with the least amount of cement. The total sum of these percentages divided by 100 gives the fineness modulus. In this method, the samples of both coarse and fine aggregate are passed through a set of 10 standard sieves, and the sample retained on each of these sieves is determined.
It is the usual method used for designing mixes for producing controlled concrete. Also, Read - What are the Properties of fresh Concrete? Fineness modulus method For impermeable construction, it is quite a suitable method. The mixture that shows the smallest volume for the same weight means one, which is the densest, is adopted.