混杂纤维增强内养生水泥混凝土力学、收缩及断裂性能研究  

Study on Mechanical, Shrinkage and Fracture Properties of Hybrid Fiber Reinforced Internal Curing Cement Concrete

作　　者：莫石秀 郭寅川[2] 覃潇[2] 杨景玉 凡俊涛 MO Shi-xiu;GUO Yin-chuan;QIN Xiao;YANG Jing-yu;FAN Jun-tao(Guangdong Road and Bridge Construction Development Co.,Ltd.,Guangzhou Guangdong 510635,China;School of Highway,Chang'an University,Xi'an Shaanxi 710064,China)

机构地区：[1]广东省路桥建设发展有限公司,广东广州510635 [2]长安大学公路学院,陕西西安710064

出　　处：《公路交通科技》2021年第8期1-8,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51778061,51908130);广东省交通运输厅科技项目(科技-2017-02-011)。

摘　　要：为明确玄武岩-聚丙烯混杂纤维与超吸水性聚合物(super-absorbent polymer,SAP)内养生剂对水泥混凝土性能的协同增强效果,借助抗压强度试验、弯曲试验、干燥收缩试验及平板塑性开裂试验,研究了混杂纤维掺量对SAP内养生水泥混凝土力学性能、断裂性能及收缩、抗裂性能的影响规律。基于扫描电镜试验,揭示了混杂纤维和SAP对水泥混凝土的增韧阻裂机理。结果表明:混杂纤维的掺入可有效提升水泥混凝土抗压强度和抗弯拉强度;混杂纤维-SAP改性水泥混凝土的断裂能相比SAP改性混凝土提高了105.95%,单位面积总开裂面积降低了73.7%;混合纤维与SAP的加入显著降低了水泥混凝土的收缩率,同时减少了混凝土收缩稳定所需时间;SAP所释放的内养生水分有效促进了胶凝材料的水化反应,而同时混杂纤维可对基体起到增韧作用,二者的有效结合对于增强水泥混凝土的力学性能和抗裂性能具有积极意义。In order to clarify the coupling enhancement effect of basalt-polypropylene hybrid fiber and SAP internal curing agent on the performance of cement concrete,with the help of compressive strength test,bending test,dry shrinkage test and plate plastic cracking test,the influence of the content of hybrid fiber on the mechanical properties,fracture properties,shrinkage properties and crack resistance of SAP internal curing cement concrete is studied.Based on the SEM test,the mechanism of toughening and cracking resistance of cement concrete by hybrid fiber and SAP is revealed.The result shows that(1)the compressive strength and flexural strength of cement concrete can be improved by adding hybrid fiber;(2)compared with SAP modified concrete,the fracture energy of hybrid fiber-SAP modified cement concrete is increased by 105.95%,and the total cracking area per unit area is reduced by 73.7%;(3)the addition of hybrid fiber and SAP significantly reduced the shrinkage of cement concrete,and also reduced the time required for concrete shrinkage stability;(4)the internal curing moisture released by SAP effectively promoted the hydration reaction of the cementitious materials,while the hybrid fiber can toughen the matrix,the effective combination of them has positive significance for strengthening the mechanical properties and crack resistance of cement concrete.

关 键 词：道路工程 内养生水泥混凝土 超吸水性聚合物 混杂纤维 收缩性能 断裂性能 增韧阻裂机理 

分 类 号：U414[交通运输工程—道路与铁道工程]