基于快速碳化试验的结构混凝土抗碳化性能研究

Study on Carbonation Resistance of Structural Concrete Based on Rapid Carbonation Test

针对某水工混凝土结构实体,对不同部位、不同强度的不带浆层芯样(A类试件)、带自然碳化浆层芯样(B类试件)进行了快速碳化试验,分别建立了A、B类试件在自然碳化环境下的碳化深度预测方程。结果表明:A类试件的早期碳化深度小于B类试件;随着碳化时间的增长,A类试件的碳化深度会超过B类试件;混凝土的抗压强度越大,A、B类试件达到相同碳化深度所需的时间越长;A类试件的碳化速度系数大于0.50,而B类试件的碳化速度系数小于0.50,说明自然碳化浆层能在一定程度上延缓碳化;基于A、B类试件建立的试验室碳化深度预测方程可用于混凝土结构抗碳化性能的合格性判定;基于B类试件建立的自然碳化深度预测方程的精度较高。

A rapid carbonation test was conducted on different parts and strengths of concrete structural entities in a certain hydraulic concrete engineering,including core sample without mortar layer(type A specimen)and core sample with natural carbonation mortar layer(types B specimen),and the prediction equations for carbonization depth of type A and type B specimen in natural carbonization environment were established respectively.The results show that the early carbonization depth of type A specimen is lower than that of type B specimen.As the carbonization time increases,the carbonization depth of type A specimen will exceed that of type B specimen.The greater the compressive strength of concrete,the longer it takes for type A and type B specimen to reach the same carbonization depth.The carbonization rate coefficient of type A specimen is greater than 0.50,while the carbonization rate coefficient of type B specimen is less than 0.50,indicating that the natural carbonization mortar layer can delay carbonization to a certain extent.The experimental carbonation depth prediction equations established based on type A and type B specimen can be used for determining the qualification of the carbonation resistance of concrete structure.The accuracy of the natural carbonation depth prediction equation established based on type B specimen is high.