高温后烧结普通砖砌体抗剪性能试验研究  

Experimental study on shear performance of fired common brick masonry after high temperature

作　　者：赵长勇[1] 高立堂[1] 崔文松 ZHAO Changyong;GAO Litang;CUI Wensong(School of Civil Engineering,Qingdao Technological University,Qingdao 266520,China)

机构地区：[1]青岛理工大学土木工程学院,青岛266520

出　　处：《建筑结构》2024年第14期125-132,118,共9页Building Structure

摘　　要：既有砖砌体结构建筑发生火灾后,砂浆强度、砖与砂浆的粘结性能均有较为明显的下降,进而影响砌体的抗剪性能及抗震性能。为了解高温后烧结普通砖砌体抗剪性能的下降规律,制作了砌筑烧结普通砖砌体试件36个,分别开展常温、200、400℃和500℃后的剪切试验,测试不同温度环境下试件的温度场,绘制常温、200、400℃和500℃后试件剪切荷载-位移曲线。结果表明:相比于常温下烧结普通砖砌体抗剪强度,随着温度环境升高,试件的抗剪强度降低;烧结普通砖砌体试件发生剪切破坏时,变形在2mm以内,为典型的脆性破坏;在同一温度环境下,伴随烧结普通砖砌体水泥砂浆强度增大,试件的抗剪强度和峰值位移随之增大;使用同等强度水泥砂浆,伴随温度环境的升高,试件抗剪强度降低,峰值位移稍稍增加;拟合高温后烧结普通砖砌体残余抗剪强度,提出高温后烧结普通砖砌体抗剪强度计算方法,抗剪强度计算值与试验值吻合较好。After a fire in an existing brick masonry buildings,both the strength of mortar and the bond performance between bricks and mortar exhibit noticeable decreases,subsequently affecting the shear resistance and seismic performance of the masonry.In order to understand the degradation pattern of shear resistance in fired common brick masonry after high temperatures,36 fired common brick masonry specimens were fabricated and subjected to shear tests at room temperature,200,400℃and 500℃respectively.The temperature face-fields of the specimens under different temperature were measured,and the shear load-displacement curves of the masonry specimens after room temperature,200,400℃and 500℃were plotted.The results indicate that compared with the shear strength of fired common brick masonry at room temperature,the shear strength of specimens decreases as the temperature increases.When shear failure occurs in the fired common brick masonry,deformation is within 2mm,indicating typical brittle failure.Under the same temperature conditions,as the strength of cement mortar in fired common brick masonry increases,the shear strength and peak displacement of the specimens also increase.Using cement mortar with same strength,as the temperature increases,the shear strength of the specimens decreases while the peak displacement slightly increases.Residual shear strength of fired common brick masonry after high temperatures was fitted,and a calculation method for shear strength of fired common brick masonry after high temperatures was proposed,the calculated shear strength values are in good agreement with experimental values.

关 键 词：高温 烧结普通砖 抗剪强度 变异系数 

分 类 号：TU362[建筑科学—结构工程]