| 摘要: |
| 通过对埋入水闸挡土墙混凝土中的温度计、应变计、钢筋计等监测仪器所采集数据的综合分析，得出了该水闸挡土墙混凝土开裂的具体原因.分析结果表明：该挡土墙混凝土开裂主要是由于大气温度突然降低，引起混凝土急剧收缩，而收缩又受到墙体两侧柱子及墙内钢筋的约束，从而产生较大的收缩拉应力，且产生的拉应力超过同龄期混凝土抗拉强度，最终引起混凝土开裂.针对该挡土墙混凝土开裂的主要原因，为了降低水工混凝土因收缩引起开裂的风险，提出了在混凝土浇筑前采取减少水泥浆用量、掺入适量膨胀剂，以及在混凝土浇筑成型后采取潮湿养护和保温养护的建议. |
| 关键词: 混凝土 收缩 约束 裂缝 |
| DOI： |
| 分类号:TU528.01 |
| 基金项目:中央级公益性科研院所基本科研业务费专项资金重点项目（Y412005，Y412001） |
|
| Cause analysis of typical crack on a sluice retaining wall and its prevention measures |
|
WEI Hua1, CHEN Xun-jie1, WEI Zhi-wen2, NIU Zhi-guo1, HU Zhi-nong1
|
|
1.State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute;2.Hubei Exploration & Design Institute of Water Conservation & Hydroelectric Engineering
|
| Abstract: |
| The authors have comprehensively analyzed the data collected from monitoring instruments， such as thermometers， strain gauges and reinforcement meters which are embedded in the sluice retaining wall. So the fundamental reasons of concrete cracking of the sluice retaining wall are obtained. The research results show that the reason for the sluice retaining wall cracking is the sudden drop of the atmospheric temperature. The temperature decrease causes the concrete shrinking which is constrained by two sides of pillars and inter reinforcement， and at the same time, the shrinkage tensile stress appears too. Crack appears when the shrinkage tensile stress is over the tensile strength of the concrete. Therefore， before the pouring of the concrete， reducing the amount of slurry and mixing with an appropriate amount of expansive agent are suggested. And after concrete pouring， curing with moisture and heat preservation materials is suggested too. These recommendations are suggested in order to reduce the risk of hydraulic concrete cracking which is caused by shrinkage. |
| Key words: concrete shrinkage constraint crack |
