Investigation of the Recycling Efficiency of Ornamental Natural Stone Sludge Powder into Preblended Polymer-Modified Self-Leveling Mortars for Industrial and Construction Applications

The current study evaluates the recycling capacity and utilization of the ornamental natural stone sludge waste in the manufacturing process of industrial preblended polymer-modified self-leveling mortars (SLMs). This recycling process of ornamental natural stone sludge is intended to improve the flow, strength, and overall quality of the proposed preblended polymer-modified self-leveling mortar used for flooring applications. The current research work also highlights several positive environmental impacts, making it an inspiring dual solution to waste management strategies and sustainable practices for natural materials. The prepared mortars were formulated with different replacement percentages of the sludge powder instead of natural fine sand aggregate. In this work, the raw materials were characterized using various techniques. In addition, the results indicated that increasing the replacement levels of the used sludge powder by 20–30% improves the overall physico–mechanical properties of the prepared polymer-modified self-leveling mortars, SL2 and SL3, which have the maximum recorded values of compressive strength at 7 and 28 days of 36 and 47 MPa, respectively. The obtained results also reveal that the used sludge powder plays both a pozzolanic role and an acceleration role during the cement hydration reaction of the prepared self-leveling mortars. Finally, the prepared self-leveling formulations (SL2 and SL3) can be industrially manufactured and used commercially for screed smoothing compound applications, offering both environmental and economic benefits due to the proposed recycling process of ornamental stone sludge.