Experimental investigation of the utilization of quarry dust for the production of microcement-based building elements by self-flowing molding casting

• Use of limestone dust for the production of self-flowing castable building elements.
• Cement/filler ratio affects compressive strength and water absorption of specimens.
• Microsilica/cement ratio plays an important role in water absorption values.
• All specimens fulfill technical specifications for load bearing building elements.
• Developed mix design methodology was proven reliable and practical.

The management and disposal of fine by-products produced by the aggregate industry, ready-mix concrete and asphalt concrete installations (also known as filler or quarry dust), emerges as a major environmental problem of quarrying and construction sector. Even though considerable research has been undertaken for the utilization of this fine by-product in several applications, it still remains under-utilized, while its disposal and stabilization is also problematic due to resulting emissions of airborne particle pollutants. In this study the production of self-flowing castable cement-based building elements incorporating high amounts of quarry dust was investigated in laboratory scale. Quarry dust, microcement, water and concrete admixtures were mixed and casted in steel molds for the production of the specimens. The initial study of mixtures composition was based on the Andreassen particle packing model, while the final mix design was determined via Box–Behnken fractional factorial design of experiments, in combination with the response surface method. The compressive strength and water absorption values of hardened specimens exceed the relevant technical requirements currently in force, regarding load-bearing as well as decorative building elements, thus opening a new promising field for the utilization of this by-product.