Sustainable High-Performance Fiber-Reinforced Concrete Using Low-Grade Pyrophyllite as a Cement Substitute

High-performance concrete (HPC) is essential for contemporary infrastructure due to its enhanced strength, durability, and resistance to environmental degradation, which contribute to extended service life and reduced maintenance requirements. Nevertheless, the production of HPC encounters challenges concerning the availability and quality of raw materials, including cement, aggregates, and admixtures. The scarcity of natural resources, environmental considerations, and rising costs necessitate the exploration of alternative materials such as pyrophyllite. The utilization of such supplementary materials not only addresses the scarcity of raw materials but also fosters sustainable construction by diminishing reliance on traditional cement, which is energy-intensive to produce. This study investigates the incorporation of low-grade pyrophyllite as a partial cement substitute in high-performance fiber-reinforced concrete. Pyrophyllite was employed at replacement rates of 7.5%, 10%, and 12.5% by mass of cement in concrete mixtures comprising Portland cement, water, silica sand, and 1% volume polypropylene fibers. The findings indicate that increasing the pyrophyllite content reduces concrete density while enhancing mechanical strength, with optimal performance observed at a 10% replacement rate. Although the mechanical strength did not exceed that of the reference concrete at 28 days, the use of pyrophyllite demonstrates potential for improving concrete properties while utilizing alternative raw materials.