A meso-scale numerical model is established to simulate concrete cracking induced by the three-dimensional (3D) corrosion expansion of helical strands in the present study. A 3D corrosion expansion model is proposed to consider the longitudinal helix shape and transverse flower-like shape of the strand. The concrete in the model is considered as a three-phase composite material consisting of a mortar matrix, aggregate, and interfacial transition zones (ITZ) between the mortar matrix and aggregate. The rationality of the proposed model is validated, and the effects of the space helix structure and the lay length of the strand on corrosion-induced cracking are discussed. The results indicate that considering the space helix structure of a strand can effectively improve the prediction accuracy of strand corrosion-induced concrete cracking. The change in strand lay length has little effect on the critical corrosion loss of the initial damage occurrence. The critical corrosion loss at cover cracking increases with increasing strand lay length, whereas the corrosion-induced crack width decreases with increasing strand lay length.

在本研究中，建立了细观数值模型来模拟由螺旋绞线的三维 (3D) 腐蚀膨胀引起的混凝土开裂。提出了一种3D腐蚀膨胀模型，以考虑钢绞线的纵向螺旋形状和横向花状形状。模型中的混凝土被认为是由砂浆基体、骨料以及砂浆基体和骨料之间的界面过渡区 (ITZ) 组成的三相复合材料。验证了所提出模型的合理性，讨论了空间螺旋结构和绞股绞合长度对腐蚀开裂的影响。结果表明，考虑钢绞线的空间螺旋结构可以有效提高钢绞线腐蚀诱发混凝土开裂的预测精度。绞合长度的变化对初始损伤发生的临界腐蚀损失影响不大。保护层开裂时的临界腐蚀损失随着绞线长度的增加而增加，而腐蚀引起的裂纹宽度随着绞线长度的增加而减小。