导电超高性能混凝土的弯敏感知特性和荷载-挠度关系  

Bending Sensitive Characteristics and Load-Deflection Relationships of Conductive Ultra-High Performance Concrete

作　　者：王艳 李奥阳 张少辉 郭冰冰 牛荻涛 WANG Yan;LI Aoyang;ZHANG Shaohui;GUO Bingbing;NIU Ditao(School of Materials Science and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;State Key Laboratory of Green Building,Xi'an University of Architecture and Technology,Xi'an 710055,China;School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055 [2]绿色建筑全国重点实验室,西安710055 [3]西安建筑科技大学土木工程学院,西安710055

出　　处：《硅酸盐学报》2025年第2期416-427,共12页Journal of The Chinese Ceramic Society

基　　金：国家优秀青年科学基金(52222806);国家自然科学基金面上项目(52078414);陕西省杰出青年科学基金(2022JC-20)。

摘　　要：碳纤维为工程结构的智能化建设提供了新途径,但其成本仍远高于其他纤维。利用废弃碳纤维(WCFs)制备了导电超高性能混凝土(C-UHPC),探究了C-UHPC的受弯性能、弯敏感知特性和荷载-挠度关系。结果表明:掺WCFs降低了C-UHPC的抗压强度。C-UHPC电阻率随WCFs掺量的增加而降低,当WCFs掺量为1%(体积分数)时,C-UHPC电阻率下降了99.89%,达到导电阈值。高掺量WCFs(>1%)会使C-UHPC韧性下降。弯曲应力下,C-UHPC的荷载-挠度曲线可分为弹性阶段、弯曲硬化阶段、破坏阶段。掺WCFs后C-UHPC具有受弯机敏特性,以峰值荷载为变化节点,峰前荷载的电阻曲线基本不发生波动,峰后荷载的电阻曲线快速上升。基于现有模型,建立了适用于C-UHPC的受弯荷载-挠度本构模型。最后,引入应力、应变灵敏度分析了不同WCFs掺量下C-UHPC弯曲应力、应变与电阻的关系。Introduction In modern society,the electricity is the foundation of all intelligent facilities.To realize the intelligent development of cementitious materials,electrical conductivity is one of the important directions for the future research of engineering structures and building materials.Of which,ultra-high performance concrete(UHPC)has been widely used in large-span building structures,tunnel and bridge structures,and repair and reinforcement projects,etc.If the conductive properties of UHPC are realized,and its self-sensing characteristics are given to achieve the demand of intelligent monitoring,it is of great theoretical significance and practical value to ensure the service safety of the building structure.It has reached a consensus at present that UHPC is modified by adding conductive materials to reduce the resistivity.However,conductive materials are expensive and difficult to achieve large-scale engineering applications.The use of waste carbon fibers(WCFs)can not only meet the performance requirements,but also reduce the preparation cost,improve the utilization rate of resources,and avoid environmental pollution.But at this stage,there is a lack of research on the influence of WCFs on the electrical conductivity of UHPC,and the relationship between electrical conductivity and load-deflection needs to be explored.Therefore,this paper took the electrical conductivity and bending performance of UHPC as the research point,and analyzed the bending sensitivity and load-deflection relationship of C-UHPC under different WCFs content.And the variation law between stress,strain and resistance was explored.Methods The UHPC with conductive properties was prepared by WCFs and steel fiber(SF),and the final mix ratio was determined by combining theoretical analysis and pre-experimental research.The water-binder ratio of C-UHPC was 0.16,and the content of WCFs was 0%,0.5%,1.0%,1.5%,and 2%(in volume),respectively.Due to some differences between WCFs and virgin carbon fibers(VCFs),a comparative study of the two fibers

关 键 词：超高性能混凝土 废弃碳纤维 导电性能 弯敏感知 荷载-挠度 

分 类 号：TU528[建筑科学—建筑技术科学]