Effect of cement content on transport in concrete

In this study the effect of cement content on transport processes important to the durability of concrete structures is assessed. Four basic concretes , each at four cement contents (300, 350, 400 and 450 kg/m(3)) and held at a constant free water/cement ratio without the use of admixtures, were test ed for their resistance to oxygen diffusion, oxygen permeation, water absor ption, electrical conduction, chloride diffusion and carbonation. Despite t he wide range of transport processes and different pre-conditioning regimes involved, it was found that in all cases, resistance to transport reduced as cement content was increased. The results are reviewed with regard to th e effects of cement content on the microstructure of concrete and on the du rability of concrete structures.