水工混凝土检测技术质量评价研究

Research on Quality Evaluation of Hydraulic Concrete Inspection Technology

评估20世纪初建造的大型结构的原始混凝土状况是安全审查计划的重要组成部分。然而,在大多数大型混凝土结构中,多年来一直在进行修复工程,只有少数案例得到了很好的记录。此外,在大多数情况下,原始混凝土可以隐藏在新的修复材料层下,并且无法进行适当的评估。现场超声脉冲速度(UPV)测量可指示原混凝土的损伤程度。然而,UPV受混凝土混合料特性的影响,这可能导致对结果的模糊解释。提出的混凝土质量指标(CQD)旨在确定混凝土相对于其原始和未受损状态的损伤程度。该CQD基于现场和实验室UPV之间的比较,并根据所研究混凝土混合物的特性进行了校正。提出了一个案例研究,其中CQD方法是在水工结构上进行的。结果表明,化学需氧量是一种准确的方法,对极低和极高程度的损害都非常敏感。

The original concrete condition assessment of large structures constructed in the early 20th century is an important part of the safety review plan. However, in most large concrete structures, repair work has been carried out for many years and only a few cases have been well documented. In addition, in most cases, raw concrete can be concealed under new layers of repair material and cannot be evaluated appropriately. In-situ ultrasonic pulse velocity(UPV) measurements can indicate the extent of damage to the original concrete. However, UPV is affected by the properties of concrete mixtures, which may lead to a vague interpretation of the results. The concrete quality data(CQD) is proposed to determine the extent of damage to concrete relative to its original and undamaged state. The CQD is based on comparisons between field and laboratory UPVs and is corrected according to the properties of the concrete mixtures studied. This paper presents a case study in which the CQD method is applied to the hydraulic structure. The results show that chemical oxygen demand is an accurate method and is very sensitive to extremely low and high levels of damage.