Sustainable development of self-compacting concrete incorporating granite waste and recycled concrete aggregate: Evaluation of strength, durability, and microstructure

Abstract

This study investigates the sustainable development of self-compacting concrete (SCC) using recycled concrete aggregate (RCA) and granite cutting waste (GCW) as partial replacements for natural aggregates. A total of thirteen SCC mixes were developed by replacing natural coarse aggregate (NCA) with RCA at two levels: 50 % and 100 %, and substituting natural fine aggregate (NFA) with GCW at five levels: 10 %, 20 %, 30 %, 40 %, and 50 %. The mechanical, durability, shrinkage, and microstructural properties were systematically evaluated. The experimental program included compressive strength, initial surface absorption, water permeability, drying shrinkage, chloride penetration, carbonation depth, and corrosion potential. Additionally, scanning electron microscopy (SEM) was used to assess pore structure and interfacial transition zones (ITZ). Results showed that RCA incorporation alone (R50G0 and R100G0) led to reductions in strength and durability due to higher porosity and weaker ITZ. However, the inclusion of GCW up to 30 % significantly improved performance. Mix R50G30 achieved around 4 % higher compressive strength than R50G0 at 90 days and showed a 41 % reduction in carbonation depth. Water absorption, chloride penetration, and shrinkage were also minimized at optimum GCW replacements. SEM images confirmed that GCW improved matrix density and pore refinement, particularly in R50G30 and R100G20. Conversely, more than 30 % GCW caused strength and durability to decline due to poor paste coverage and microcracks. Overall, the study highlights the synergistic use of RCA and GCW in producing durable, eco-efficient SCC, reducing dependency on natural resources while enhancing sustainability in construction.