摘要
本文对现行国家与行业标准中常用于长龄期混凝土强度检测的钻芯法、回弹法-龄期修正系数法及回弹-钻芯修正法(修正量法)进行了介绍与总结,分析了各方法在推定混凝土强度方面的优缺点。结合北京地区某既有住宅楼混凝土剪力墙的强度检测案例,分别采用上述3种方法对剪力墙检测批的混凝土强度进行推定。在本工程案例中,以钻芯法检测结果为基准,回弹-钻芯修正法(修正量法)的推定结果与钻芯法接近;而回弹法-龄期修正系数法的推定结果仅为钻芯法结果的81.6%,且低于设计要求混凝土强度等级,仅达到设计强度的84.3%,其标准差较钻芯法低17.5%,相对误差较大,且偏于保守,不能真实反映该剪力墙检测批的混凝土强度现状。因此,在长龄期混凝土强度检测中,建议优先选用钻芯法或回弹-钻芯修正法(修正量法)。若工程条件不适宜取芯,回弹法-龄期修正系数法的推定结果仅供参考,未来仍需研究适用于长龄期混凝土的回弹法测强曲线,以满足实际检测要求。
This paper introduces and summarizes the core drilling method,the rebound hammer method with age correction coefficient,and the rebound-core drilling correction method(correction value method),which are commonly used in current national and industry standards for detecting the strength oflong-aged concrete.It analyzes the advantages and disadvantages of each method in estimating concrete strength.Using a case study involving the strength inspection of concrete shear walls in an existing residential building in Beijing,the above three methods are applied to estimate the concrete strength of a batch of inspected shear walls.In this project case,with the core drilling results as the benchmark,the estimation results from the rebound-core drilling correction method are close to those of the core drilling method.In contrast,the estimation result from the rebound hammer method with age correction coefficient is only 81.6%of the core drilling result,falling below the required design strength grade and reaching only 84.3%of the design strength.Its standard deviation is 17.5%lower than that of the core drilling method,exhibiting a relatively large error.The result is conservative and fails to accurately reflect the actual strength condition of the concrete in the inspected shear wall batch.Therefore,for strength detection oflong-aged concrete,priority should be given to the core drilling method or the rebound-core drilling correction method.If core sampling is not feasible in a project,the estimation result from the rebound hammer method with age correction coefficient is for reference only.Future research is still needed to develop a suitable rebound hammer strength curve for long-aged concrete to meet practical inspection requirements.
出处
《混凝土世界》
2025年第12期60-64,共5页
China Concrete
关键词
长龄期混凝土
强度检测
回弹法
钻芯法
龄期修正系数法
Long-aged concrete
strength detection
rebound hammer method
core drilling method
age correction coefficient method
