Full-scale pumping tests of low-viscosity ultra-high-strength concrete

Low-viscosity ultra-high-strength concrete (UHSC) was newly developed by applying viscosity reduction methods, and full-scale pumping tests were performed on a pumping circuit with a total length of 525 m for the low-viscosity UHSC including 150 MPa, 180 MPa UHSC and 180 MPa ultra-high-strength fiber-reinforced concrete (UHSFRC). Concrete properties such as temperature, air content, slump flow, viscosity, compressive strength, and modulus of elasticity before and after pumping were compared. As a result, it was confirmed that pumping caused considerable changes in the properties of fresh concrete. In addition, the pumpability of the low-viscosity UHSCs was evaluated by measuring the pressure of the pipe and the discharge. It was found that the smaller the viscosity and the larger the pressure loss (pressure per unit pipe length), the larger the discharge. •Low-viscosity ultra-high-strength concrete (UHSC) is successfully developed.•A full-scale pumping test is conducted with a total circuit length of 525 m.•Pumping leads to considerable changes in the properties of fresh concrete.•Smaller viscosity and larger pressure loss cause larger discharge.•Fiber addition is possible with insignificant influence on the pumpability of UHSC.