Mass Concrete Mixtures Based on Fineness Modulus and Geometrical Gradation

Abstract

Ideal and optimum fineness moduli are used in combination with the geometrical gradation of aggregates to establish the mix proportioning of mass concrete. The ideal and optimum fineness moduli are experimentally determined for each maximum size of aggregate (MSA) by making concrete mixtures with aggregates of different fineness modulus and determining which of the mixtures give the highest compressive strength for a given cement-to-aggregate ratio. For each MSA, an adequate number of cement-to-aggregate ratios is selected and at least three different water-to-cement ratios are used in order to cover a broad range of strength. Also, for each cement-to-aggregate ratio, five mix proportions with different amounts of sand are studied. Geometrical gradations are used for comparison and for smoothening-out proposed gradations. Geometrical gradation is also utilized as a criterion for the concrete mix proportioning when large aggregates (152 mm) are used. Experimental results are used to exemplify the method.