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论文类型：期刊论文

发表时间：2016-06-01

发表刊物：INTERNATIONAL JOURNAL OF FRACTURE

收录刊物：SCIE、EI、Scopus

卷号：199

期号：2

页面范围：229-244

ISSN号：0376-9429

关键字：Moisture diffusion; Drying shrinkage; Concrete repair system; Fracture spacing

摘要：The shrinkage cracking processes in a cement-based composite, which include crack initiation, propagation and coalescence, as well as diffusion-damage coupling, are numerically studied using a mesomechanical numerical model to better understand the shrinkage cracking growth mechanisms and the effects of cracks on moisture diffusion. This study analyzes the shrinkage crack initiation and growth processes in a repair layer of mortar, which is cast on the top of an old concrete substrate and initially saturated with water. The potential shrinkage crack development is driven by the associated drying process. The results illustrate the fracture infilling, saturation and delamination processes in the concrete repair system by decreasing the bond strength between the repair mortar and the substrate from 4 to 1MPa. Large concrete repair system bond strengths cause cracks to initiate on the surface of the repaired mortar and propagate to the interface. However, debonding is observed at lower bond strengths. The numerical model is shown to be a viable tool for damage analyses under both mechanical loads and hygral gradients.