东南亚地区某碾压混凝土坝裂缝成因及防治措施研究

Study on the Crack Causes and Prevention Measures for the Roller Compacted Concrete Dam in Southeast Asia

混凝土裂缝是影响水工结构强度和耐久性的主要因素之一,东南亚地区全年高温多雨,月均最大温差较小(8.6℃),年均温差大(20.2℃),混凝土温度容易控制,但裂缝问题时有发生。依托东南亚地区某碾压混凝土坝,采用有限元研究施工期温度应力的变化规律,分析混凝土开裂的敏感因素,并就其温控防裂措施开展详细研究。结果表明,浇筑长间歇及寒潮侵袭显著影响混凝土温度应力的变化,老混凝土的强约束作用及新老混凝土的温差影响叠加寒潮应力,导致混凝土应力超标出现温度裂缝。在上述研究的基础上,进一步探讨了降低新浇混凝土温度应力的温控措施,为东南亚地区大体积混凝土工程的建设提供一定的参考。

Concrete cracking is one of the primary factors affecting the strength and durability of hydraulic structures.The Southeast Asian region experiences high temperatures and heavy rainfall throughout the year,with a small average monthly maximum temperature difference of 8.6℃and a large average annual temperature difference of 20.2℃.Although concrete temperature is relatively easy to control,cracking issues still occur.Based on the roller-compacted concrete dam in Southeast Asia,the characteristics of temperature stress during the construction period were studied using finite element.Sensitivity factors for concrete cracking were analyzed,and detailed research was conducted on temperature control and crack prevention measures.The results show that the long intervals between pouring and cold wave have a significant impact on the change of concrete temperature stress.The strong constraint effect of old concrete and the temperature difference between fresh and old concrete add up to cold stress,leading to concrete stress exceeding the limit and temperature cracks.Furthermore,temperature control measures were explored to reduce thermal stress in newly poured concrete,providing valuable references for the construction of large-volume concrete projects in Southeast Asia.