不同粉煤灰掺量及水胶比水工混凝土的耐久性分析

Durability Analysis of Hydraulic Concrete with Different Fly Ash Content and Water-binder Ratio

根据东北地区气候环境特征,试验设计3种粉煤灰掺量及水胶比,通过模拟设计现场侵蚀条件试验探讨不同粉煤灰掺量及水胶比水工混凝土耐久性。结果表明:不同侵蚀环境的作用机理存在明显差异,自然浸泡、冻融循环条件下以化学腐蚀和物理破坏为主,干湿循环与硫酸盐侵蚀耦合作用会引起一系列物理化学反应;各类侵蚀环境下,掺20%粉煤灰+0.30水胶比试块的耐久性最优,硫酸盐溶液中水泥水化生成钙矾石,这种膨胀产物会产生一定的膨胀压力。

According to the climatic and environmental characteristics of northeast China,three kinds of fly ash content and water-binder ratio were designed,and the durability of hydraulic concrete with different fly ash content and water-binder ratio was discussed through the field erosion condition test of simulated design.The results show that there are obvious differences in the action mechanism of different erosion environments,under natural soaking and freeze-thaw cycles,chemical corrosion and physical damage are the main factors,and the coupling of dry-wet cycle and sulfate erosion will cause a series of physical and chemical reactions.In various erosion environments,the durability of the block mixed with 20%fly ash+0.30 water glue is the best,the cement in sulfate solution is hydrated to form ettringite,and this swelling product will produce certain swelling pressure.