(1 上海城建市政工程 (集团) 有限公司, 上海 200065;2 上海交通大学船舶海洋与建筑工程学院, 上海 200243)

摘要: 采用足尺模型模拟地基沉降对养护期混凝土结构影响,通过对典型混凝土样本的大功率 X 射线切片扫描和三维重构,研究了不同养护龄期混凝土在地基沉降作用下内部结构、微裂缝及其断裂损伤状态. 结果表明:地基沉降量及沉降时间对混凝土胶结状态有不同程度影响,地基沉降量越大,其粗骨料与周围的胶结情况越差,内部微裂缝出现的概率更高;初凝混凝土受地基沉降作用后,粗骨料周边易被折断或拉裂,萌生张拉裂缝;混凝土内部孔隙、裂纹、缺陷等损伤区域在地基沉降作用下存在扩展演化和微裂缝相互贯通和断裂局部化的可能性,对结构抗渗性和耐久性存在影响. 研究结果可为大型污水处理池等混凝土结构抗渗设计提供参考.

关键词: 地基沉降; 混凝土微结构; X 射线切片扫描; 三维重构; 断裂损伤评价

中图分类号:TU317 文献标志码:A 文章编号:1002-848X(2023)05-0076-07

DOI:10. 19701 / j. jzjg. 20210724

X-ray experimental study on internal damage state of concrete structure under the action of foundation settlement

RONG Jian1, WANG Yingyi2

(1 Shanghai Urban Construction Municipal Engineering (Group) Co. , Ltd. , Shanghai 200065, China;2 School of Naval Architecture, Ocean & Civil Engineering, Shanghai Jiaotong University, Shanghai 200243, China)

Abstract: The full-scale model was used to simulate the influence of foundation settlement on concrete structure in curingperiod. Through high-power X-ray slice scanning and 3D reconstruction of typical concrete samples, the internal structure,micro cracks and fracture damage state of concrete under the action of foundation settlement in different curing periods werestudied. The results show that the settlement amount and settlement time of the foundation have different degrees ofinfluence on the cementation state of the concrete. The greater the settlement amount of the foundation is, the worse thecementation between the coarse aggregate and the surroundings is, and the higher the probability of internal micro cracksis. After the initial set concrete is disturbed by the foundation settlement, the periphery of coarse aggregate is easy to bebroken or cracked around, and tensile cracks are initiated. Under the action of foundation settlement, the damage areassuch as pores, cracks and defects in concrete have the possibility of propagation evolution, micro-cracks interpenetrate eachother and fracture localization, which have an impact on the impermeability and durability of the structure. The researchresults can provide a reference for the impermeability design of concrete structures such as large sewage treatment ponds.

Keywords: foundation settlement; microstructure of concrete; X-ray slice scan; 3D reconstruction; fracturedamage assessment

第一作者:荣建,硕士,高级工程师,一级建造师,主要从事地下和结构工程施工技术与理论研究,Email:rj8152@ 163. com.

[引用本文] 荣建,王颖轶. 地基沉降作用下混凝土结构内部损伤状态 X 射线试验研究[ J]. 建筑结构,2023,53(5):76-82,75. RONG Jian,WANG Yingyi. X-ray experimental study on internal damage state of concrete structure underthe action of foundation settlement[J]. Building Structure,2023,53(5):76-82,75