Rheological and mechanical behavior of self-compacting mortars containing marble waste as a partial replacement of sand

Materials recycling presents a compelling economic case for waste disposal sites and the conservation of natural resources. This study delves into the substitution of cement with varying percentages of marble waste (0%, 10%, 20%, 30%, 40% and 50%). The water-to-binder ratio is consistently set at 0.44 for all mixes. Chemical admixtures such as superplasticizers or viscosity agents are frequently added to the mortar to improve its flow and strength. We conducted mini-slump flow and rheometer tests to assess the fresh mixes' rheological properties, as well as tests to measure the compressive and tensile strength of the mixes. The findings indicate that including marble powder enhances the mechanical properties of self-compacting mortar. A substantial 29% enhancement was achieved for a mixture incorporating 30% marble waste. The most favorable rheological properties, including slump flow, yield stress, and superior mechanical performance in compressive and tensile strength, were observed in the mix containing 30% marble powder waste. Furthermore, the investigation showed that the self-compacting mortar with a yield stress of 0.98 MPa at a 50% MW replacement rate and a viscosity of 1.4 Pa.S can achieve a slump flow of 25-31 cm. These findings illustrate marble waste potential as a valuable addition to self-compacting mortar (SCM) manufacturing, delivering improved performance and structural integrity. However, specific application scenarios and long-term endurance restrictions require further investigation. Practical effects include the possibility of developing inventive, sustainable, and economic SCM compositions, which will help to advance construction practices and sustainability. The social ramifications include reducing environmental impact and increasing resource efficiency in the construction industry.