Optimisation of the aggregates composition in concrete

Hardened concrete has a complex structure in which two parts can be distinguished - the matrix (hardened cement-sand grout) and the insertion of coarse aggregate particles. The aggregates make up to 80 % by volume of concrete. The cost of aggregates also reaches 30 % - 50 % of that of concrete. Therefore it is natural that aggregates largely affect the structure, physical-mechanical properties and price of concrete. In the present paper, the authors propose a mathematical method to design the grading of concrete aggregates. This method could provide a possibility to obtain more precise design of aggregates composition. This method is based on limiting by curves the maximum and minimum quantities of a mineral part of concrete mixture that can be passed through particular sieves