勾缝加固砖砌体墙的抗压性能试验

为研究勾缝加固方法对砌体墙抗压性能的影响及加固效果,根据不同勾缝深度和加固砂浆强度,设计12个勾缝加固砌体构件和3个未加固构件,并对其进行了轴压试验,分析了勾缝深度和加固砂浆强度对加固砌体墙的开裂荷载、破坏荷载、应力-应变曲线和弹性模量的影响.试验及分析结果表明,相比未加固构件,勾缝加固构件的破坏形态和破坏过程相似,但其开裂荷载降低,而破坏荷载和弹性模量提高,提高的幅度与勾缝深度、加固砂浆强度有关,最大达到30%.根据试验数据和理论分析,基于砌体结构设计规范中的公式,提出了考虑勾缝深度和加固砂浆强度影响的勾缝加固砌体墙的抗压强度、应力-应变曲线和弹性模量的计算公式,且公式的计算结果与试验结果吻合较好.因此,勾缝方法可以用于砌体墙的加固,特别是近现代历史建筑.

Experimental study on compressive behavior of masonry walls strengthened with pointing mortar

To study the effect of pointing mortar on the compressive behavior of masonry walls, according to different depth and strength of the pointing mortar, twelve wall specimens reinforced with pointing mortar and three unreinforced specimens were tested under uniaxial compression. Two test parameters, depth and strength of the pointing mortar, were investigated in terms of their effects on the cracking load, failure load, stress-strain relationship and elastic modulus of the reinforced specimens. Test results show that, compared to the unreinforced specimens, the specimens reinforced with pointing mortar exhibit a decrease in cracking load and an increase in both failure load and elastic modulus. And the increase range depends on the depth and strength of the pointing mortar, in which the largest reaches 30%. The cracking patterns and failure modes are similar for both reinforced and unreinforced specimens tested. Based on the test data and theoretical analysis, according to the formula from the code for design for masonry structures, equations that account for the depth and strength of the pointing mortar are proposed for predicting the compressive strength, stress-strain curve and elastic modulus of the pointed masonry walls. The test results also indicate that pointing can be used as a means of reinforcing masonry walls, especially for the historical buildings.