Properties of blended mortars produced with recycled by-products from different waste streams

The construction industry encounters significant challenges in effectively managing solid waste produced during the extraction and production of building materials. In different countries, slurry waste generated from granite and marble processing industries, such as glass industry waste, constitutes a considerable portion of the total solid waste. Its undesirable disposal is causing unprecedented environmental damage. Using these non-biodegradable wastes to produce building materials would reduce the environmental burden and contribute to sustainable construction. This study, in detail, investigates the feasibility of utilizing Granite Powder (GP), Ground Granite Powder (GGP), and Ground Glass Waste (GGW) as partial replacements of components in blended mortar mixes. The mix modifications consist of partial replacement of cement with GGW, GP, and GGP in the range of 5–15% and fine aggregate replacement with Marble powder (MP) in 10–30% by mass. The mechanical, physical, and microstructure properties of blended and control mortar mixes were studied on the 3rd, 7th, 28th, and 91st curing days. The results demonstrate that the partial substitution of 10% GGW and 5% GP with cement and 10% MP with fine aggregates in blended mortars enhance the compressive strength at the later curing age (28 and 91 days) compared to that of a control mortar, which is associated to the development of higher pozzolanic reactivity. The XRD results showed the formation of the lowest content of calcium hydroxide (CH) and the highest content of calcium silicate gel in the blended mortars compared to the control mortar. The results enrich the data available in the literature not always univocal, as in the case of using marble and glass waste, providing also interesting information about the influence of granite powder on the hydration process in a mortar mix actually missing