湿热环境下玄武岩纤维桥面混凝土早期抗裂性  

Research on e Early Cracking Resistance of Basalt Fiber Bridge Deck Concrete in Hot and Humid Environment

作　　者：郭寅川[1] 杨雪瑞 申爱琴[1] 李震南 左孝森 GUO Yinchuan;YANG Xuerui;SHEN Aiqin;LI Zhennan;ZUO Xiaosen(School of Highway,Chang’an University,Xi’an 710064,China)

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《郑州大学学报（工学版）》2023年第6期99-104,118,共7页Journal of Zhengzhou University（Engineering Science）

基　　金：国家自然科学基金资助项目(52078050)。

摘　　要：针对南方湿热地区桥面铺装易开裂、耐久性下降等问题,选取玄武岩纤维作为混凝土增强材料,在室内模拟标准、湿热2种养护环境,设计塑性收缩试验、干燥收缩与湿度分布试验以及圆环约束开裂试验,探究湿热环境下玄武岩纤维桥面混凝土的早期开裂行为。结果表明:湿热环境下,玄武岩纤维桥面混凝土塑性开裂得到抑制,其单位面积总开裂面积大幅减小,较基准混凝土减少了76.5%;玄武岩纤维桥面混凝土内部相对湿度的变化为其干缩变形发展的驱动力,通过掺入纤维可以减缓混凝土板内部相对湿度下降从而抑制其干燥收缩开裂,相比于基准混凝土板,纤维混凝土板中心处与角隅处的28 d干燥收缩变形分别降低了27.5%、25.5%;玄武岩纤维的掺入能够抑制混凝土环的约束开裂,提高混凝土抗裂性。Aiming at the problems of cracking and the durability reduction in hot and humid areas of southern China,basalt fibers were selected as concrete reinforcement materials.In simulated standard,hot,and humid curing environments indoors,the plastic shrinkage test,drying shrinkage test,humidity distribution test and circular ring restrained test were designed to explore the early cracking behavior of basalt fiber bridge deck concrete in hot and humid environment.The results showed that plastic cracking of basalt fiber bridge concrete was restrained in hot and humid environment.Compared with the reference concrete,its total cracking area per unit area was significantly reduced by 76.5%.The change of relative humidity in basalt fiber bridge deck concrete was the driving force for its development of drying shrinkage deformation.The decrease of relative humidity in the concrete slab could be slowed down by adding fiber,so as to inhibit its drying shrinkage cracking.The 28 d drying shrinkage deformation at the center and corner of the fiber reinforced concrete slab was 27.5%and 25.5%lower than that of the reference concrete.Besides,the incorporation of basalt fibers could inhibit the restrain cracking of concrete rings and improve cracking resistance of concrete.

关 键 词：玄武岩纤维 桥面铺装 湿热环境 早期抗裂性 

分 类 号：TV431[水利工程—水工结构工程] TU528[建筑科学—建筑技术科学]