PROPERTIES OF PASTE-ROCK INTERFACES AND THEIR INFLUENCE ON COMPOSITE BEHAVIOR

The results are presented of an investigation into the interfacial pro perties of composite materials based on plain and silica fume pastes, and andesite, dolomite and granite rocks used as commercial concrete a ggregates. Microstructural studies are reported, and the observations are shown to assist qualitatively in the interpretation of mechanical test results. Fracture properties of the various combinations show tha t the mechanical response of the composites is material specific. In g eneral, andesites develop superior interfacial bond properties, and th e use of silica fume tends to embrittle composites. For the mix propor tions and materials used in this study, no direct (micrographic) evide nce of a transition zone between interface and bulk paste cor!ld be ob served.