基于损伤场的混凝土氯离子渗透性研究

Study on Cl- penetration resistance of concrete based on damage fields

混凝土微裂纹缺陷会对氯离子渗透性能产生一定的影响。通过对混凝土多方位的劈拉试验构建均匀损伤场,同时对损伤前后的混凝土试块进行氯离子渗透试验,研究微裂隙损伤场对混凝土氯离子渗透性能的影响。在劈拉试验中,通过数字散斑技术获得对应不同劈拉方向的MCOD值,建立基于微裂纹损伤面积ω和加权弹模衰减EL值的损伤场变量DE,并进一步分析了该损伤变量与氯离子扩散系数D之间的关系。

Micro-crack defects in concrete can affect the Chloride ion permeability of concrete in a certain extent.In the paper, the split-ting experiments of concrete specimens from the four different dimensions are carried out in order to build the even damage fields.The dis- placements of the concrete specimens＇ surface are analyzed through DSCM （Digital Speckle Correlation Method ）.Therefore damage pa rameters are determined that are damage area o） based on the MCOD（Micro-Crack Opening Displacement ） and damage variable DE based on the weighting-damping elastic modulus.At the same time, Cl^- permeation of concrete specimens before and after the splitting test are studied by NEL method, and Cl^- diffusion coefficients D are recorded in detail.Further relationships between damage parameters and diffu-sion coefficients of Cl^- are discussed.