荷载-温度耦合影响下混杂纤维/混凝土三轴压缩渗透行为被引量：2

Triaxial compression permeability behavior of hybrid fiber reinforced concrete under load-temperature coupling

导出

摘要为了研究荷载-温度耦合作用对仿钢纤维(Imitation steel fiber,ISF)和聚乙烯醇纤维(Polyvinyl alcohol fiber,PVAF)混掺的混凝土三轴压缩渗透性能影响及ISF-PVAF混杂纤维/混凝土渗透率演化与应力状态的关系,开展固定围压和渗透水压条件下的三轴压缩渗透试验,获得应力-变形曲线、峰值强度及各应力点处渗透率,结合SEM从内部微观结构变化角度揭示宏观性能改变机制。结果表明:荷载与温度耦合作用使混杂纤维/混凝土孔隙率呈现出先略微降低后大幅上升的趋势,最大增幅达到80.48%,不利于三轴压缩渗透强度的发展;初始渗透率增加尤其是受温度因素影响增幅更加明显,200℃和300℃作用时初始渗透率相对于100℃分别提高了144.60%、291.55%。根据应力-变形曲线特征,三轴压缩渗透过程可分为初始压密阶段、弹性阶段、裂纹发展阶段、软化阶段,应力状态的改变使混杂纤维/混凝土内部微裂纹及残余纤维通道随之变化,直接影响到孔隙水渗流路径,相应地渗透率在各应力阶段表现出大幅下降、相对平稳、急速上升、增幅最大等特征。 Aiming at studying the effect of load-temperature coupling on the triaxial compressive permeability of concrete mixed with imitation steel fiber(ISF)and polyvinyl alcohol fiber(PVAF),research on the relationship between permeability evolution and stress state of ISF-PVAF hybrid fiber concrete was conducted.The triaxial compression permeability test under the condition of fixed confining pressure and seepage water pressure was carried out to obtain the stress deformation curves,peak strength and permeability at each stress point.Combined with SEM,the change mechanism of macro properties was revealed from the perspective of internal micro structure change.Results show that the coupling effect of load-temperature makes the porosity of hybrid fiber concrete decrease slightly at first and then increase significantly,the maximum increase reaches 80.48%,which is not conducive to the development of triaxial compressive permeability strength.While the behavior of initial permeability increasing is more affected by temperature,the initial permeability increases by 144.60%and 291.55%respectively at 200℃and 300℃compared with 100℃.According to the characteristics of stress deformation curve,the triaxial compressive permeability process is divided into four stage:Initial compaction stage,elastic stage,crack development stage and softening stage.The variation of stress state leads to the changes of micro cracks and residual fiber tunnels in hybrid fiber concrete,which directly affects the seepage path of pore water.As a result,the permeability in each stage exhibits different characteristics:Sharply decreasing,gently changing,rapidly rising and maximum increasing,respectively.

作者薛维培范红君高聪张瀚文申磊 XUE Weipei;FAN Hongjun;GAO Cong;ZHANG Hanwen;SHEN Lei(State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China;Institute of Environment-friendly Materials and Occupational Health,Anhui University of Science and Technology,Wuhu 241003,China)

机构地区安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室安徽理工大学环境友好材料与职业健康研究院(芜湖)

出处《复合材料学报》 EI CAS CSCD 北大核心 2022年第11期5548-5556,共9页 Acta Materiae Compositae Sinica

基金安徽省自然科学基金项目(1908085QE185,2208085ME146) 安徽省住房城乡建设科学技术计划项目(2021-YF58) 深部煤矿采动响应与灾害防控国家重点实验室自主课题(SKLMRDPC20ZZ05) 安徽理工大学环境友好材料与职业健康研究院研发专项基金(ALW2021YF14) 安徽省大学生创新创业训练计划项目(S202110361046) 安徽理工大学研究生创新基金(2020CX2032)。