钻芯法和回弹法检测隧道衬砌混凝土强度的相关性

Correlation Between Concrete Inspection Strengths of Tunnel Lining Using Core Drilling Method and Rebound Method

按照铁路隧道衬砌常用的混凝土配合比,制作混凝土模型试件。在不同龄期下进行回弹、钻芯试验,测得回弹法抗压强度与ϕ100 mm、高径比为1∶1的芯样抗压强度,对比分析两种检测方法所测强度的关系。对部分在建铁路开展隧道衬砌边墙混凝土钻芯法与回弹法对比检测,研究回弹法在工程质量监督检测中的可实施性。试验表明,回弹法抗压强度与芯样抗压强度成正相关关系,钻芯法检测强度明显高于回弹法检测强度,且在56 d龄期后仍有增长。回弹法适用于建设过程中的混凝土强度普查,不宜直接用于监督检测。

According to the common concrete mix proportion of railway tunnel lining,concrete model specimens were made.At different ages,rebound and core drilling tests were carried out to measure the compressive strength of rebound method and compressive strength ofϕ100 mm core sample with height diameter ratio of 1∶1.By comparing the measured strengths,the relationship between the measured values under two detection methods was analyzed.For some railways under construction,the core drilling method and rebound method for tunnel lining side wall concrete were compared to study the feasibility of rebound method in project quality supervision and inspection.The test shows that the compressive strength of the rebound method is positively related to the compressive strength of the core sample.The strength detected by the core drilling method is significantly higher than that detected by the rebound method,and it still increases after 56 d of age.The rebound method is applicable to the general survey of concrete strength in the construction process,and should not be directly used for supervision and detection.