Effects of different fine aggregates on the properties of ultra-high strength concrete

Abstract

When a coarse pore-structured fine aggregate with a large water absorption was used for concr- ete with a water-binder ratio of 0.12, unit water content of 135 kg/m3, and sand-aggregate ratio of 55%, the mobility, strength, and elastic modulus of concrete increased, with the autogenous shrinkage becoming extr- emely low. The authors attributed the reason for this phenomenon to the internal curing effect of fine aggre- gate based on tests using mortar samples and the properties of fine aggregate. The authors also considered that one reason for the increased strength of concrete is the reduction in the autogenous shrinkage of the mo- rtar phase, which reduces the risk of failure under local stress, based on the stress-strain relationship of con- crete and mortar under compressive deformation.