Mass concrete mixtures based on fineness modulus and geometrical gradation

Ideal and optimum fineness moduli are used in combination with the geometri cal gradation of aggregates to establish the mix proportioning of mass conc rete. The ideal and optimum fineness moduli are experimentally determined f or each maximum size of aggregate (MSA) by making concrete mixtures with ag gregates of different fineness modulus and determining which of the mixture s give the highest compressive strength for a given cement-to-aggregate rat io, For each MSA, an adequate number of cement-to-aggregate ratios is selec ted and at least three different water-to-cement ratios are used in order t o cover a broad range of strength. Also, for each cement-to-aggregate ratio , five mix proportions with different amounts of sand are studied. Geometri cal gradations are used for comparison and for smoothening-out proposed gra dations. Geometrical gradation is also utilized as a criterion for the conc rete mix proportioning when large aggregates (152 mm) are used. Experimenta l results are used to exemplify the method.