盐湖地区干燥气候和碳化作用对混凝土强度和耐久性的影响

Durability of concrete in salt lake Ⅰ:Influences of desiccation and carbonation

研究了干燥气候和碳化作用对混凝土力学性能和耐久性的影响规律。结果表明,在30%RH和50%RH条件下的养护,不仅降低了混凝土的力学性能,而且严重降低了其抗冻性和抗卤水冻蚀性,碳化作用显著改善了混凝土的抗卤水冻蚀性。干燥环境养护混凝土的冻融寿命只有标准养护的12%～24%,在内蒙古盐湖卤水中,其腐蚀—冻融寿命仅达到标准养护的31%～76%。当混凝土碳化以后,其腐蚀—冻融寿命比碳化前延长了7～18倍。

Influences of desiccation and carbonation on mechanical property and durability of concrete were investigated.Results show that both mechanic performance and freezing-thawing resistance,including pure water and bittern freezing-thawing,were diminished for concrete cured in 30% or 50% relative humidity,while carbonation could improve the bittern freezing-thawing resstance remarkably.Freezing-thawing life of concrete samples cured in low relative humidity was about 12%～24% of those cured in standard environment,and freezing-thawing life of carbonized samples were prolorged by 7～18 compared with those which had not been carbonized.