某码头工程现浇上横梁裂缝的成因及控制技术

Causes and control techniques of cracking in cast-in-place upper beam in a wharf

为解决某码头工程首件制4道现浇上横梁出现竖向裂缝的问题,分析研究了材料、环境、设计及施工等方面的原因,通过修改现浇垫块与上横梁的钢筋位置、调整混凝土水灰比、延迟拆模和加强养护等措施,采用在实际施工中进行效果验证的方法,取得显著的治理效果,裂缝完全控制在规范允许的范围内。同类型上横梁,可在上述治理措施相关的几个方面进行对照研判,尤其是在配筋及施工顺序方面,根据实际情况作相应调整,可取得较好的竖向裂缝防治效果。

In order to tackle the vertical cracks in the first batch of 4 cast-in-place upper beams for a wharf,the causes in materials,environment,design and construction are analysed and studied.By modifying the position of reinforcement in the cast-in-place cushion block and the upper beam to make the two elements independent,adjusting the water-cement ratio of concrete,delaying the removal of formwork and intensifying the curing process,and by verifying the foresaid measures in practical construction,remarkable result has been achieved in crack controlling and the cracks are completely controlled within the allowable range as stipulated in the specifications.For the same type of upper beams,the above-said measures can be compared with and judged in several aspects for crack control,in particular,the reinforcement and construction sequence can be adjusted as appropriate according to the actual situations,and better result in prevention and control of vertical cracks can be achieved.