Akademik Veri Yönetim Sistemi
Journal of the Australian Ceramic Society, 2025 (SCI-Expanded, Scopus)
Construction and demolition waste (CDW) represents approximately 25–30% of total waste production in the EU, necessitating innovative recycling strategies to achieve the mandated 70% recycling rate. This study systematically investigates the performance of calcined concrete waste powder (CCWP) as a sustainable supplementary cementitious material (SCM) for partial Portland cement replacement in mortar mixtures. Six mortar compositions with CCWP replacement levels of 0%, 10%, 20%, 30%, 40%, and 50% were evaluated through comprehensive mechanical testing, microstructural analysis, durability assessment under aggressive environments, and life cycle assessment. The calcination process at 1000 °C for 2 h enhanced the pozzolanic reactivity of concrete waste by transforming calcium hydroxide into reactive phases. Results demonstrate that 20% CCWP replacement achieves optimal performance, delivering 99 MPa compressive strength at 90 days (7.6% improvement over control) while maintaining 101.7% of reference flexural strength. Microstructural analysis via ultrasonic pulse velocity confirmed enhanced densification, with UPV increasing from 4.23 km/s to 4.56 km/s. Durability testing revealed superior acid resistance with 50–53% reduction in mass loss under H₂SO₄ exposure and improved brine resistance. Environmental assessment indicates 20% CCWP reduces CO₂ emissions by 4.1% (932.81 kg/m³) and production costs by 3.3% ($175.80/m³), achieving optimal eco-efficiency ratios of 9.42 kg CO₂/MPa and $1.78/MPa. Higher replacement levels (≥ 30%) resulted in decreased mechanical properties due to dilution effects, despite continued environmental benefits. The findings validate CCWP’s viability as a sustainable SCM at moderate replacement levels, contributing to circular economy principles while maintaining structural integrity and reducing the construction industry’s carbon footprint.