Effect of Silica Fume and Glass Powder on High-Strength Paste

Glass powder is known as a reactive material with silica content more than 72% and potentially considered as pozzolanic material. Moreover, it is known that binder containing silica fume 10-26% by weight increases the compressive strength of concrete. A low water to binder ratio is needed to increase the strength. In this paper, materials for making paste were analyzed for X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and reactivity. Composition of paste with the highest strength at 28 days was 93.26 MPa. Glass powders had higher reactivity compared to silica fume. Therefore, the recommended amount of glass powder to increase mechanical properties is 10 – 15% from cement weight and silica fume content are 40 – 60% from glass powder weight. A tendency of strength increasing after 28 days was found. In general, addition of silica fume to glass powder prolonged the initial setting causing the distance between initial and final setting time became closer.