CAJ | 학술논문

混凝土保护层锈裂严重影响钢筋混凝土结构的耐久性。为了研究混凝土保护层的锈裂行为，考虑到混凝土细观结构的非均质性以及钢筋锈蚀的非均匀性，将完好混凝土视为由骨料、砂浆和界面过渡区组成的三相复合材料，建立了细观随机骨料模型。在模型中，钢筋的非均匀锈蚀行为以施加非均匀径向位移的方式模拟，骨料的力学行为假定为弹性，砂浆和界面过渡区的力学特性采用塑性损伤模型来描述。在此基础上进行了中部钢筋非均匀锈蚀引发的混凝土保护层开裂行为的细观数值模拟；分析结果与已有文献中的试验结果吻合良好。另外，对比了均质模型和非均质模型中钢筋均匀锈蚀和非均匀锈蚀导致的保护层开裂模式；并探讨分析了保护层厚度和钢筋直径对保护层开裂模式、钢筋锈胀压力及保护层开裂时钢筋锈蚀率的影响。
혼응토보호층수렬엄중영향강근혼응토결구적내구성。위료연구혼응토보호층적수렬행위，고필도혼응토세관결구적비균질성이급강근수식적비균균성，장완호혼응토시위유골료、사장화계면과도구조성적삼상복합재료，건립료세관수궤골료모형。재모형중，강근적비균균수식행위이시가비균균경향위이적방식모의，골료적역학행위가정위탄성，사장화계면과도구적역학특성채용소성손상모형래묘술。재차기출상진행료중부강근비균균수식인발적혼응토보호층개렬행위적세관수치모의；분석결과여이유문헌중적시험결과문합량호。령외，대비료균질모형화비균질모형중강근균균수식화비균균수식도치적보호층개렬모식；병탐토분석료보호층후도화강근직경대보호층개렬모식、강근수창압력급보호층개렬시강근수식솔적영향。
Concrete cover cracking induced by corrosion of steel reinforcement is a major influencing factor for durability and serviceability of reinforced concrete structures . In order to investigate the cracking process of concrete cover induced by rebar corrosion ,the heterogeneity of concrete meso‐structure and non‐uniformity of rebar corrosion are accounted for .The undamaged concrete is assumed to be a three‐phase composite material composed of aggregate ,mortar matrix and the interfacial transition zone (ITZ) .And a concrete random aggregate structure is established for the study on the mechanical behavior of the non‐uniform radial corrosion expansion .In the present simulations ,non‐uniform radial displacement is adopted to simulate the non‐uniform corrosion of the rebar ;the plasticity damaged model is used to describe the mechanical behavior of the mortar matrix and the ITZ ,and the aggregate is assumed to be elastic .The cracking of concrete cover due to the non‐uniform corrosion of the middle located rebar is numerically simulated .The comparison of the analysis and the test result on failure pattern of cover concrete shows fairly good agreement .And then the failure patterns under uniform corrosion and non‐uniform corrosion obtained from the macro‐scale homogeneous model and the meso‐scale heterogeneous model are compared . Furthermore ,the influences of concrete cover thickness and rebar diameter on the failure pattern of concrete cover ,the expansive pressure and the corrosion rate of the rebar w hen cover concrete cracks are investigated .