Performance and eco-efficiency of high-strength concrete incorporating a screened quaternary low-carbon binder

This study investigates the development and performance of high-strength concrete designed for an M65 target grade incorporating an optimized quaternary low-carbon binder system comprising Ordinary Portland Cement (50%), Class F fly ash (20%), ground granulated blast furnace slag (15–25%), and calcined seashell powder (5–15%). Binder proportions were systematically investigated using an S/N-ratio-based comparative screening approach to rank the predefined mixtures based on compressive strength. A comprehensive experimental evaluation was conducted to assess mechanical properties, durability characteristics, and eco-efficiency. Results indicate that the incorporation of industrial and aqua-industrial waste materials significantly reduces carbon footprint and embodied energy compared to conventional OPC-based concrete, while demonstrating continued strength development at later ages and enhancing long-term durability. The developed quaternary binder system demonstrates strong potential as a sustainable and practically viable solution for high-performance concrete, promoting effective waste valorisation and contributing to the objectives of the United Nations Sustainable Development Goals (SDGs 9, 12, and 13).