冻融条件下新老混凝土粘结后抗折性能  

Adhesive Bending Properties of New-old Concrete Under Freeze-thaw Conditions

作　　者：黄伟[1] 方张平[1] HUANG Wei;FANG Zhangping(School of Architecture and Art,Huainan Union University,Huainan 232038,China)

机构地区：[1]淮南联合大学建筑与艺术学院,安徽淮南232001

出　　处：《材料科学与工程学报》2021年第5期745-749,767,共6页Journal of Materials Science and Engineering

基　　金：安徽省高校科学研究资助项目(KJ2018A0719);安徽省优秀人才支持计划资助项目(皖教秘人[2014]181号)。

摘　　要：对经历0、10、20、30、40和50次冻融循环的混凝土试块进行抗折强度试验,分析新老混凝土外观特征、动弹性模量、质量损失率和抗折强度等参数与冻融循环次数之间的变化规律。结果表明:每间隔10次冻融循环后,新老混凝土试样的表观剥蚀逐渐加重,质量损失率初期略有降低、后期快速增长,试件的抗折强度和动弹性模量衰减较快;Ⅰ型和Ⅱ型粘结面试件抗折破坏主要集中粘结面处;Ⅲ型和Ⅳ型粘结面试件的破坏面从粘结面处逐渐向试件强度低的一侧转移。增加黏结面粗糙度,可以有效提高冻融环境下新老混凝土的抗折强度。In order to research adhesive bending properties of new-old concrete under freeze-thaw cycle,bending strength tests were carried out on concrete blocks undergoing 0,10,20,30,40 and 50 freeze-thaw cycles,and the variation rules between the appearance characteristics,dynamic elastic modulus,mass loss rate,the bending strength of new-old concrete and the number of freezing-thawing cycles were analyzed.The test results show that intervals of 10 times after freeze-thaw cycle,the apparent denudation of new-old concrete increases gradually,the mass loss rate decreases slightly at the beginning and increases rapidly at the later stage,and the bending strength and dynamic elastic modulus of concrete decline rapidly.The adhesive parts bending damage of type Ⅰ and type Ⅱ mainly focused on the bonding surface.The bonding failure surface of type Ⅲ and type Ⅳ shifted from the bonding surface gradually to the side of low specimen strength.It is concluded that under the same conditions,the increase the bond surface roughness can effectively improve the bending strength of the new-old concrete under the condition of freeze-thaw.

关 键 词：新老混凝土 冻融循环 抗折强度 动弹性模量 粘结面粗糙度 

分 类 号：TU501[建筑科学—建筑技术科学]