Physical filling effect of aggregate micro fines in cement concrete

To quantitatively explain the physical filling effect of aggregate micro fines (AMF), a formula was established, and the amount of free water in fresh concrete mixture can be calculated with the formula. The designed example showed that the variation regularities of slump and compressive strength were the same as that of the amount of free water in fresh concrete mixture as the amount of limestone AMF changes, which shows the physical filling effect of limestone AMF plays an important role in improving performances of concrete.