钻芯法检测砖砌体加固前后基本力学性能

Drilled Core Method for Testing Basic Mechanical Properties of The Brick Masonry Before and After Reinforcement

摘要:

针对我国量大面广的砖砌体结构，提出了采用钻芯法检测其加固前后基本力学性能的方法，以提供用于评定采用各种砂浆面层加固砖砌体效果的方法。设计了可同时用于加固前后芯样抗压强度、界面剪切强度的试验加载附属装置，完成了315个芯样以及54个砖砌体标准件强度试验，同时进行了4种不同表面处理工况下界面剪切强度试验。抗压强度试验结果表明，加固前后芯样的抗压强度均与相对应的砌体标准件抗压强度具有很好的相关性，加固前相关系数建议取值为MU7.5取2.13，MU10和MU15均取2.25；加固后相关系数建议取3.26。界面剪切强度试验结果表明，加固面层与砖砌体之间的界面剪切强度受砂浆、块体强度等级影响较小，主要受基层砖砌体表面的不同处理手段影响较大。加固前后芯样抗压强度值与相应标准件的强度相关性以及芯样界面剪切强度呈现的规律性基本说明采用本文的钻芯法检测砖砌体结构加固前后基本力学性能的方法是可行的。

Abstract:

This paper proposed a novel method, which named the drilled core method, to test the basic mechanical properties of brick masonry before and after reinforcement. The method can be popularized to evaluate the effect of brick masonry reinforced by various mortar surface. An auxiliary loading device was designed to test the compressive strength and interface shear strength of core samples. Strength tests of 315 core samples and 54 standard brick masonry parts were successfully completed by using auxiliary loading device. After that, the interfacial shear strength tests under four different surface treatment conditions were completed to verify the feasibility for evaluating the interfacial shear strength after reinforcement. The compressive strength test results indicate that the compressive strength of core samples correlates strongly with the standard brick masonry parts. Before reinforcement, the correlation coefficient of compressive strength between core samples and standard brick masonry parts is suggested as 2.13 for MU7.5, 2.25 for both MU10 and MU15. After reinforcement, the correlation coefficient is suggested as 3.26 for all the masonry strength grade. The interfacial shear strength test results show that the interfacial shear strength between the strengthened surface layer and the brick masonry is less affected by mortar and block strength grade, but mainly by different treatment methods of brick masonry surface. All the test results show that, it is feasible to test the basic mechanical properties of brick masonry structure before and after reinforcement by using the proposed drilled core method for brick masonry structure.