Abstract: To determine the appropriate stone powder content in tuff manufactured sand, we prepared concrete specimens mixed with tuff manufactured sand which contains three levels of stone powder content at Xiamen pumped storage power station, and investigated the effects of stone powder content on the rheological properties, mechanical properties, early cracking resistance, and drying shrinkage of hydraulic pumped concrete. Results showed that an increase in tuff stone powder content from 8% to 18% caused an increase in unit water consumption, yield stress, and plastic viscosity of hydraulic pump concrete, as well as a decrease in early-age cracking resistance and an increased dry shrinkage, while the compressive strength and splitting tensile strength were only slightly affected. When the content of tuff stone powder was reduced to 8%, the hydraulic pumped concrete exhibited inferior cohesion and water retention. The optimal tuff stone powder content was found to be around 13% to improve the overall properties of the hydraulic pumped concrete.

Key words: hydraulic pump concrete, rheological properties, early cracking resistance, drying shrinkage, stone power content, tuff