Utilization of Barite Powder as a Partial Replacement for Silica Sand in Heavy-Weight HPC

The development of high-density cementitious composites is critical for specialized applications such as heavy-duty structural components. This study investigates the impact of replacing silica sand with barite powder on the physical, mechanical, and microstructural properties of cementitious composites. The replacement levels varied from \0% to 100% to evaluate the extent of property modification. Experimental results indicate a significant positive correlation between barite content and composite density, which increased by 17.6% to reach a maximum of 2857 kg/m3 at 100% replacement. However, this densification was accompanied by a systematic degradation in mechanical performance. At the 100% replacement level, compressive, tensile, and flexural strengths decreased by 26.4%, 30.2%, and 34.1%, respectively. Furthermore, water absorption nearly doubled, increasing from 1.9% in the control to 3.8% in the 100% barite mix. Scanning Electron Microscopy (SEM)-based microstructural observations suggest that the decline in mechanical performance and the increase in permeability are consistent with weak aggregate–matrix adhesion. The study concludes that while barite is highly effective for increasing composite density, the resulting increase in porosity and loss of cohesive strength must be carefully managed through mix optimization to ensure structural durability.