水化温升抑制剂对混凝土性能的影响

Influence of hydration temperature rise inhibitor on concrete performance

水泥水化温升产生的温度应力是混凝土出现裂缝的主要原因,研究了不同掺量水化温升抑制剂对C50混凝土拌合物性能、混凝土绝热温升、抗压强度和抗氯离子渗透性能的影响规律。结果表明:水化温升抑制剂对混凝土拌合物流动性有一定影响,凝结时间大幅度延长,绝热温升可降低8%~29%;水化温升抑制剂延缓了胶凝材料的水化进程,使得混凝土的7 d抗压强度大幅降低,但不影响水泥和矿物掺合料的最终水化程度,56 d抗压强度较不掺时的降幅不大于10%;掺加水化温升抑制剂降低了混凝土的28 d抗氯离子渗透性能,但随着龄期的延长,对56 d抗氯离子渗透性能的降低幅度显著减小。

The temperature stress caused by the temperature rise of cement hydration is the main cause of concrete cracks.In this paper,the effects of hydration temperature rise inhibitors with different contents on the properties of C50 concrete mixture,adiabatic temperature rise,compressive strength and resistance to chloride ion penetration were studied.The results show that the hydration temperature rise inhibitor has a certain effect on the fluidity of concrete mixture,the setting time is greatly prolonged,and the adiabatic temperature rise can be reduced by 8%~29%.It delays the hydration process of cementitious materials,and the 7 d compressive strength of concrete is greatly reduced,but does not affect the final hydration degree of cement and mineral admixtures,the 56 d compressive strength of concrete is less than 10%lower than that of concrete without hydration temperature rise inhibitor.The addition of hydration temperature rise inhibitor reduces the 28 d chloride ion permeability of concrete,however,as the extention of age,the reduce degree to 56 d chloride ion permeability of concrete is significantly lower.