寒旱区水利工程大掺量粉煤灰混凝土试验研究

High Volume Fly Ash Concrete for Hydraulic Engineering in Cold and Arid Regions

结合西北寒旱区水工混凝土冻融破坏特点,对等强度和等水胶比配制的粉煤灰混凝土在不同龄期下的力学、抗冻融及抗渗性能进行了研究。结果表明:大掺量粉煤灰虽然早期强度较低,但中后期强度增长较快;等强度配制条件下,粉煤灰混凝土的抗冻融性和冻后自愈合能力以及抗渗性能随粉煤灰掺量的增大并未明显减弱;当水胶比在0.35,粉煤灰掺量在50%时,混凝土的力学性能、抗冻融性能和抗渗性能均较突出,能够较好地满足西北寒旱区水利工程建设的要求。

The freeze-thaw damage of concrete is a severe problem for hydraulic structure in cold and arid regions in Northwest China. In this research, we investigated the mechanical properties, freeze-thaw resistance and impermea- bility of fly ash concrete with uniform strength and water-cement ratio at different ages. The strength of high volume fly ash concrete in the early stage was lower than common ones, but the strength grew rapidly in the mid-late ages. The freeze-thaw resistance, self-healing ability and the impermeability of fly ash concrete with uniform strength were not significantly weakened when fly ash content was increased. When the water-cement ratio and the fly ash content were 0. 35 and 50% respectively, the mechanical properties, freeze-thaw resistance and impermeability of the concrete were prominent and able to meet the requirements of water project construction in the northwest cold and arid regions.