To address SDG12 (ensure sustainable consumption and production patterns), and to provide technical evidence for alternative concrete constituents to traditional natural river sand, stone fine aggregate (SFA), brick fine aggregate (BFA), ladle-refined furnace slag aggregate (LFS), recycled brick fine aggregate (RBFA), and washed waste fine aggregate (WWF), ready-mix concrete plants were investigated. Concrete and mortar specimens were made with different variables, such as replacement volume of natural sand with different alternative fine aggregates, water-to-cement ratio (W/C), and sand-to-aggregate volume ratio (s/a). The concrete and mortar specimens were tested for workability, compressive strength, tensile strength, and Young’s modulus (for concrete) at 7, 28, and 90 days. The experimental results show that the compressive strength of concrete increases when natural sand is replaced with BFA, SFA, and LFS. The optimum replacement amounts are 30%, 30%, and 20% for BFA, SFA, and LFS, respectively. For RBFA, the compressive strength of concrete is increased even at 100% replacement of natural sand by RBFA. For WWF, the compressive strength of concrete increases up to a replacement of 20%. Utilizing these alternative fine aggregates can be utilized to ensure a circular economy in construction industries and reduce the consumption of around 30% of natural river sand.

Return concrete slurry waste (RCSW), a by-product of the concrete manufacturing process and a combination of leftover cement particles, cement hydration products, and fine aggregates, is often disposed of in landfills. This study aims to evaluate the usage of RCSW as a filler material in fresh mortar. A novel technique for reusing RCSW by partially replacing fine aggregate in cement mortar has been investigated in this study. Mortar samples were prepared by partially substituting 5% and 10.5% volume of the natural river sand with RCSW, incorporating both CEM Type-I and CEM Type-II A-M cement. Certain proportions of CEM Type-I cement were also partially substituted with slag and fly ash. The specimens were tested for compressive strength, sorptivity, and Ultrasonic Pulse Velocity (UPV). The results revealed that RCSW can replace a part of fine aggregate and water in mortar, paving the way toward the sustainability of construction materials.

To evaluate the potential of fly ash (FA) and ground granulated blast furnace slag (GGBFS) as supplementary cementitious materials (SCMs) in terms of sustainability and functional performance, both concrete and mortar samples were prepared with GGBFS or FA at moderate to high replacement ratios (35%, 50%, and 65%) and were tested for compressive strength, ultrasonic pulse velocity (UPV), chloride–ion penetration and migration, carbonation, and sorptivity, and the results of these tests were then used with the relative sustainability assessment of building technologies (MARS‐SC). At 28 days, the 35% GGBFS/65% ordinary Portland cement (OPC) mix achieved the highest compressive strength (~15% above plain OPC) with balanced durability, increasing GGBFS to 50–65% traded early strength for lower chloride ingress (lowest rapid chloride penetration test [RCPT]/rapid chloride migration test [RCMT] at 65% GGBFS). Plain OPC showed the best carbonation resistance, while sorptivity was highest for the 65% FA mix and lowest for the 65% GGBFS mix. Heat‐map summaries showed environmental performance improving with higher SCM content (rising from 0.44 for OPC to 0.66 for the 65%‐GGBFS mix), functional performance peaking at the 35% GGBFS mix, and economic dimension increasing with replacement level. The aggregated sustainability score (NS) identified the 35% GGBFS mix as optimal (NS = 0.74), Portland composite cement (PCC) (Type II A‐M) as the second‐best option (NS = 0.60), and the 65% FA mix as the poorest‐performing (NS = 0.42). Overall, a moderate GGBFS replacement (35%) was the most sustainable option, providing well‐balanced strength, durability, and embodied environmental impacts with suitable trade‐offs.