The influence of water glass modulus on the structure development of alkali-activated slag

Paper in proceeding, 2015

The development of alternative and greener cementitious materials based on industrial wastes is one way to reduce the environmental impact of the building sector. The main objective of this work is to perform a detailed analysis of the strength and structure of alkali-activated ground granulated blastfurnace slag at different times of hydration. In particular, we have investigated the structure development of the material by use of the complementary techniques, X-ray diffraction (XRD) and Infrared spectroscopy (IR). For the alkali-activation, water glass with various moduli was used. For all sample compositions, both the silica and water contents were kept at fixed values whereas the sodium content was systematically varied. As a consequence, the structure of the solutions used for the activation, the pH of the alkali-activated slag samples as well as the initial stage of the hydration of the samples were varied systematically. From the results it is obvious that the modulus of the water glass used for the activation has a great influence on both the strength and the structure developed, both at short and longer time of hydration. In this contribution, we will discuss how various parameters such as sodium content, pH and the structure of the solution used for the activation influence the strength and structure development of alkali-activated slag up to fourteen days of hydration