The relation between porosity, chemical degradation and fracture characteristics in mortar structures

摘要

The purpose of this paper is to quantify the influence of microstructural degradations, namely a variation of porosity, on the mechanical properties of heterogeneous quasi-brittle materials in civil engineering field (mortar, concrete). The study deals with this problem on a model mortar material (mortar + polystyrene beads). Experimental investigations on this material in compression, bending, emission acoustic measurements and their analysis are detailed. The experiments show that the elastic modulus, compressive strength and the maximal strength decrease with the mass density. The brittleness of the structures as well as the fracture energy (obtained by applying Bazant's size effect law) are decreased too. Comparison with leached mortar beams obtained by Le Belle' go (2001) are also discussed.