摘要
高延性纤维增强水泥基防火材料(FR-ECC)具有遇火不燃性、高温不分解有毒气体、耐久性良好、延性高、抗裂性能好等优点,近年来得到了广泛关注和研究。常规FR-ECC的制备采用有机纤维为增韧组分,而有机纤维在高温条件下纤维分解气化易导致防火材料延性下降,造成开裂失效,制约了FR-ECC的应用。本工作以耐高温性能优异的铝酸盐水泥和玄武岩纤维(BF)作为原材料,设计研发轻质玄武岩纤维水泥基复合材料(LWBF-ECC),并研究该材料高温后力学性能及热学性能的演化规律。试验分析了LWBF-ECC在常温和高温后的干密度变化、物相变化、单轴抗拉强度和抗压强度变化规律,并研究了其在不同过火温度下延性及导热系数的变化规律。研究表明:在常温环境下,LWBF-ECC延性可达0.82%,是常规钢结构表面喷射防火材料的80倍;由于BF耐高温性能优异,高温下仍能充分发挥桥接作用,在过火温度低于400℃时,LWBF-ECC材料拉伸均表现为应变硬化,高温下仍保持一定延性,100、200和400℃时极限应变分别为0.78%、0.32%和0.18%;随着温度升高,LWBF-ECC干密度降低,孔隙率升高,同时导热系数下降,高温下胶凝材料水化物转变和结晶水损失导致水泥含量越多,质量损失越大,干密度降低越明显。
High ductility fiber reinforced fire-resistive engineered cementitious composites(FR-ECC)have the advantages of fire inflammability,non-decomposition of toxic gases at high temperatures,and good durability.At the same time,it has the advantages of high ductility and good crack resistance,and has been widely concerned and studied in recent years.Conventional FR-ECC uses organic fiber,which is decomposed and gasification at high temperature,resulting in the ductility reduction and cracking of refractories,which restricts the practical application of FR-ECC.In this work,aluminate cement with excellent high temperature resistance and basalt fiber(BF)were used as raw materials to design and develop lightweight high ductility basalt fiber reinforced engineered cementitious composites(LWBF-ECC),and the evolution law of mechanical and thermal properties of the material after high temperature was studied.The variation rules of dry density,phase change,uniaxial tensile strength and compressive strength of LWBF-ECC at room temperature and elevated temperature were studied,and the variation rules of ductility and thermal conductivity at different temperatures were also studied.The results show that the ductility of LWBF-ECC can reach 0.82%at room temperature,which is 80 times of the conventional sprayed fire-resistant material on the surface of steel structure.Due to BF’s excellent high temperature resistance,it can still give full play to the bridging function at high temperature.When the exposure temperature is below 400℃,LWBF-ECC material shows strain hardening in tensile,and it still retains a certain ductility at high temperature.The ultimate strains at 100,200 and 400℃are 0.78%,0.32%and 0.18%,respectively.With the temperature elevated,LWBF-ECC dry density decreases,porosity increases and thermal conductivity decreases.The hydration change and water of crystallization loss of cementitious materials at high temperature leads to the higher cement content,the more mass loss,and the more obvious dry density decrease.
作者
张文雅
周健
李辉
徐名凤
ZHANG Wenya;ZHOU Jian;LI Hui;XU Mingfeng(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China)
出处
《材料导报》
CSCD
北大核心
2023年第20期273-278,共6页
Materials Reports
基金
国家自然科学基金(51878238)
河北省自然科学基金(E2021202037)。
关键词
高延性水泥基复合材料
玄武岩纤维
防火
轻质
导热性能
strain-hardening cementitious composites
basalt fiber
fire resistance
lightweight
thermal conductivity property
作者简介
张文雅,河北工业大学土木与交通学院硕士研究生,在周健教授的指导下进行研究。目前主要研究领域为高延性水泥基复合材料;通信作者:周健,河北工业大学“元光学者”特聘教授、博士研究生导师。2011年毕业于荷兰代尔伏特理工大学,获博士学位,曾赴美国密歇根大学访问研究。主要致力于建筑材料基因组工程研究。主持和参与国家自然科学基金、“十二五”国际合作、“十二五”科技支撑和“十三五”重点研发等国家级科研项目6项,省部级科研项目2项。发表学术论文40余篇,其中SCI论文10余篇,获发明专利8项,主编建材行业标准1部。zhoujian@hebut.edu.cn。
