Diabase Sludge as A New Eco-Friendly Waste for Use in Cement-Based Mortar

Appropriate waste management is recognised as being of pivotal significance for sustainable development. The utilisation of waste materials has the potential to reduce final costs and provide alternative raw materials for industrial sectors, such as construction. The ornamental rock industry is responsible for the generation of substantial amounts of waste. A number of studies have been conducted on the utilisation of stone sludge in mortars. However, no such studies were identified regarding diabase sludge from the ornamental sector, despite a substantial increase in diabase rock consumption attributable to its colour and physical properties. The impact of diabase sludge from a quarry in western Spain was examined as a cement replacement in mortar, with particular attention to consistency and fresh density. The diabase sludge, as collected (GDS), and the fraction below 63 μm (FDS) were evaluated. The experimental programme incorporated mortars with diabase sludge at varying replacement levels. The following two criteria were employed: Firstly, it is imperative to utilise the same flow values in order to guarantee uniform consistency across all mortars. Secondly, the water-to-binder (w/b) ratio must be maintained constant to evaluate the impact of diabase sludge on consistency. The mortars with 30% GDS, 20% FDS and identical flow values to the reference mortar were deemed to be the most suitable. The mortars with 20% GDS, 25% FDS and the same w/b ratio as the reference mortar have flow values that are similar.