蒸汽养护工艺对盾构管片混凝土抗碳化性能的影响

Influence of Steam-Curing Process on the carbonation of shield segment concrete

研究了不同静养时间、升温速率、恒温温度、恒温时间和降温速率对盾构管片高性能混凝土抗碳化性能的影响。结果表明,静养时间的延长,可以有效提高管片混凝土抗碳化性能;较快的升温速率、较高的恒温温度、较长的恒温时间以及较快的降温速率不利于管片混凝土抗碳化性能的增长;经试验确定盾构管片用混凝土的蒸汽养护制度为静养时间不小于2h、升温速率宜控制在10~15℃·h^(-1)、恒温温度不宜超过50℃、恒温时间宜控制在2~4h以及降温速率不超过20℃·h^(-1),在该蒸养条件下生产的盾构管片达到福州地铁工程应用的抗碳化性能设计要求。

The influence of different rest period, heating - up rate, thermostatic temperature, thermostatic period and cooling rate on the carbonation resistance of shield segment concrete was studied. The results prove that the carbonation resistance of shield segment concrete can be im- proved with a longer rest period, but decreased with a rapid heating - up rate, a higher thermostatic temperature, a longer thermostatic period and a rapid cooling rate. The steam - curing process of shield segment concrete can be determined by testing that the rest period is not less than 2h, heating -up rate should be controlled within 10 -- 15℃· h-1, thermostatic temperature should not exceed 50℃, thermostatic period should be controlled within 2 -- 4h, and cooling rate should be less than 20℃ . h -1. The shield segment under the steam - curing condition can be conform to the anti -carbonation design requirements of Fuzhou subway engineering .