The effect of different ACI normal concrete mix design parameters in predicting mix proportions and strength attainment has been studied. The parametric study reveals that the inter-particle voids, a function of gradation, in the coarse aggregate plays a significant role in mix proportion prediction. However, the ACI design method has failed to properly address this aspect. This gives unrealistic mix proportions when coarse aggregates of high void ratio is used. In this case, the amount of fine aggregate becomes very high with an increased surface area to be covered by the constant amount of cement. The strength attainment of such mixes should be very poor. The hardened strengths of trial mixes have substantiated this fact.
展开▼
