地下综合管廊混凝土爆灰检测及加固

Detection and reinforcement of concrete ash explosion in underground pipe gallery

针对某市钢筋混凝土地下综合管廊的现浇顶板、侧壁出现的混凝土爆灰质量缺陷,为确保管廊结构的安全使用,采用钻心法、超声波法、沸煮试验、爆灰物质的化学成分分析等检测方法,对爆灰现象进行了检测。结果显示,混凝土中存在的块状氧化钙与水熟化后体积增大1倍~2.5倍,使得混凝土在强度未达到设计抗拉强度前在块状氧化钙体积膨胀应力作用下被拉裂,导致了此类质量缺陷的发生。分析了质量缺陷对管廊结构的影响,并对管廊结构进行了加固设计及处理,满足了结构的正常安全使用要求。研究结果可为类似爆灰缺陷的设计及处理提供参考。

Ash explosion quality defects are found in cast-in-place concrete roof and side wall in a city underground pipe gallery.In order to ensure the safety of the underground pipe gallery,a series of tests such as core-bit,ultrasonic method,boiling test,and chemical component analysis of the ash explosion are carried out.The ash explosion is detected.The result shows that when the quicklime in concrete and water are cured,the volume will increase by 1~2.5 times.Before concrete reaches the design tensile strength,the concrete has been cracked under the volume expansion stress of the massive calcium oxide,occuring this type of quality defect.The effect of the defects on the underground pipe gallery is evaluated,and reinforcement design and treatment is carried out,meeting the safe handling requirement of the structure.The study may provide reference for the reinforcement design and treatment of similar ash explosion conditions.