The durability of concrete is a comprehensive evaluation index of its internal material properties and resistance to external en-vironmental effects.In order to study different water-binder ratio and fly ash content concrete durability performance,on the basis of con-sidering local climate and environment,with three kinds of water-binder ratio,fly ash content concrete as the research object,three kinds of durability tests of the simulation of erosion environment indoors were designed in the laboratory.Results show concrete erosion mechanism is not same in different environment.Under the condition of natural immersion,the concrete specimens are mainly subject by chemical cor-rosion.However,freezing and thawing cycle under the action of its is mainly affected by physical damage,complex physical and chemical reactions were also at the simultaneously performed in sulfate solution during the wetting and drying cycles.Water/cement ratio is 0.30 and 15% fly ash specimen have best durability in all kinds of environment.The concrete product will generate expansive ettringite in sulfate so-lution and result in high pressure expansion on the specimen.%混凝土耐久性是反应其内部材料性能和抵抗外部环境作用的一个综合性评价指标.为了研究不同水胶比及粉煤灰掺量混凝土的耐久性能,在考虑各地气候及环境的基础上,以3种水胶比及粉煤灰掺量的混凝土作为研究对象,在室内设计了模拟现场侵蚀环境的3种耐久性试验,结果表明:不同环境下混凝土侵蚀机理不同,自然浸泡环境下以化学腐蚀为主,冻融循环作用下混凝土试件则主要受到物理破坏,硫酸盐溶液中进行干湿循环时试件同时受到复杂的物理化学反应.三类试件中以水胶比是0.30,粉煤灰掺量为15%的试件在各类环境下的耐久性最好.混凝土在硫酸盐溶液中会生成膨胀产物钙矾石,对试件产生较大的膨胀压力.
展开▼
