硫酸盐环境中CFRP约束劣化混凝土柱的力学性能

为研究碳纤维增强树脂复合材料(CFRP)加固经硫酸盐腐蚀劣化后混凝土柱的力学性能，构建CFRP约束劣化混凝土的力学模型，采用CFRP约束普通混凝土后腐蚀和CFRP约束劣化混凝土两种工况进行试验，在试验研究基础上，引入损伤率及强度保持率作为损伤的量化指标，建立两者之间的关系；通过对CFRP约束混凝土强度及应变规律的回归分析，建立适用于硫酸盐环境下CFRP约束劣化混凝土的极限强度、应变模型及应力-应变关系模型。结果表明:随侵蚀时间增长，两种工况下CFRP约束混凝土极限强度和应变的变化规律及劣化速度均不同。预劣化的混凝土柱虽然进行了表面处理，但内部已经存在损伤，在侵蚀环境中采用CFRP加固混凝土柱时，应该考虑混凝土初始损伤的影响。 

Mechanical properties of CFRP confined pre-damaged concrete columns in sulfate environment

In order to study the mechanical properties of carbon fiber reinforced polymer composite(CFRP)confined concrete columns deteriorated in sulfate environment and establish corresponding mechanical models,two types of testing conditions were considered,i.e.,deterioration after confinement and confinement after deterioration.Based on the testing results,two quantitative indicators,damage ratio and residual strength ratio were introduced to represent the degree of concrete damage,and a relationship between the damage ratio and the residual strength ratio was setup.Through a regression analysis of the strength and the strain,the models for ultimate strength,ultimate strain and stress-stain relationship were given for these columns,respectively.The results show that with the corrosion time growing,the ultimate strength,ultimate strain and corrosion rate of the CFRP confined concrete are different for the both testing conditions,respectively.Before the pre-deteriorated concrete column is confined subsequently,internal damaged has occurred and will have an effect on its performance.Hence,the effect of initial damage should be considered when CFRP confined concrete columns are adopted in a corrosive environment.