The influence of interface layer on microstructural stresses in mortar

In this paper, the influence of geometrical and physical parameters (size of the sand particle, thickness of the interface layer and ratios of the modulus of elasticity) on stress distributions in a mortar is studied. It is found that a weak or soft interface layer in the mortar will greatly reduce the strength of the concrete; if the modulus of the interface layer approaches to that of the cement paste and the modulus of the sand particle (or aggregate) is 4-10 times as large as that of the cement paste, the concrete will possess a much higher strength and thus has a better property.