Study about the Optimal Proportions of Microsilica and Nanosilica in Concretes with High Durability Performance Using an Experimental Design of Hexagonal Type

An experimental design of hexagonal type was designed and realized using different proportions of micro and nanosilica in the concrete, under the condition that the sum of the two pozzolans was not over the 9.5% of the cement weight in the concrete mix. From the concrete mix design used in a very important construction of infrastructure in Cuba, with the same Portland cement and hard limestone aggregates, in each point of the experimental design was realized three repetitions of compression strengths and durability trials of the concretes and four repetitions of trials in the point of the hexagonal center. The results obtained show the possibility to obtain high performance concretes by mechanical resistance and durability, which have demonstrated to obtain an effective porosity below the 4 % and cement yields up to 0,142 MPa for each kg of cement in each cubic meter of concrete, that is to say 0,142 MPa/(kg/m(3)).