Effect of Glass-Composite Additives on the Properties of Cement-Based Products

In recent decades, replacing clinker in cement with mineral additives has become increasingly common, and the range of such additives continues to expand. An example is the growing number of cement types defined in European standards. Some of these standards allow the use of fine recycled concrete waste as an active additive in amounts up to 35%.. Finely ground waste glass, whose quantity steadily increases worldwide, can also be classified as an active additive. Due to its relatively high silica content, finely ground waste glass is a potential supplementary cementitious material. However, the high alkali content in glass limits its use in cementitious products to 5-10% of the binder mass. Considering that silicate binders (water glass) with high alkali activity are also used in construction and influence the hydration process of cement, it can be assumed that waste glass likewise has a significant impact on the properties of cement composites, particularly on hardening parameters and the development of mechanical strength. However, scientific literature lacks data on the synergistic effect of alkaline components of finely ground waste glass and water glass on the cement hydration process, its hardening, and the strength of cement products. Therefore, this study aimed to analyze the mechanism of the influence of a glass-based composite, consisting of waste glass additives and water glass, on the physicochemical and mechanical properties of cement composites.