复杂环境下粉煤灰混凝土抗硫酸盐侵蚀耐久性

我国西北地区及沿海地区的混凝土结构经常遭受多种硫酸盐侵蚀环境的共同作用而发生耐久性破坏.通过室内试验,研究了硫酸盐自然侵蚀、冻融循环-硫酸盐自然侵蚀、干湿循环-硫酸盐侵蚀、冻融-干湿循环耦合侵蚀环境下混凝土的质量损失、弹性波波速、抗压强度的变化规律.结果表明,混凝土的质量损失率、弹性波波速、抗压强度随着侵蚀时间的增加而呈现出先增加后减小的现象;混凝土的弹性波波速、抗压强度与侵蚀时间之间存在良好的相关关系.研究成果可为硫酸盐侵蚀环境下混凝土工程质量控制和耐久性评价提供理论依据.

Durability of fly ash concrete against sulfate erosion in complex environment

The durability damage of concrete structures in northwest China and coastal areas is often caused by the combined action of various sulfate erosion environments.Through laboratory experiments,the variation laws of concrete mass loss,elastic wave velocity and compressive strength under the environment of sulfate natural erosion,freeze-thaw cycle-sulfate natural erosion,dry-wet cycle-sulfate erosion,freeze-thaw-dry-wet cycle coupling erosion were studied.The results show that the mass loss rate,elastic wave velocity and compressive strength of concrete show three stages of slow rise-slow decline-fast decline with the increase of erosion time,and there is a good correlation between the elastic wave velocity,compressive strength and erosion time of concrete.The research results can provide theoretical basis for quality control and durability evaluation of concrete engineering under sulfate erosion environment.