Microcracks, fracture mechanism, and strength of the cement paste matrix

Abstract Possible relationships between fractural strenght data for porous multi-phase materials and their porosity, solid-phase composition, and crack structure are reviewed briefly, with special reference to cement paste materials. The present-day knowledge of the growth of various constituents of cement hydration microstructures is shown in a few sketches, and a attempt is made to relate the development of certain types of strength to changes in phase volume concentrations, and to variations in the solid microstructural and associated microcrack formation. Possible connection points between the observations of microstructure and strength, and the concepts and material data of elementary fracture mechanics are discussed.