Effect of paste volume on the performance of UHPC under the optimum grading of Yellow River sand

In the pursuit of high-performance building materials, this study focused on the utilization of Yellow River sand (YRS) in Ultra-High-Performance Concrete (UHPC). Based on the closest packing theory, the optimal grading combination of four grain YRS was determined. By adjusting the paste volume through varying the paste layer thickness under this combination, the synergistic design and optimization of UHPC preparation were achieved. Experimental results revealed that at the filling factor of 2.1, corresponding to a flow of 185 mm, the 28-day compressive strength reached 130 MPa. This research provided a novel approach for fabricating low-cost UHPC with excellent performance, promoting the sustainable utilization of local materials.