碳纤维轻骨料混凝土高温后动态压缩性能研究  

Dynamic compression performance of carbon fiber reinforced lightweight aggregate concrete after high temperature

作　　者：张志鹏[1] 张凯章 吴飞 ZHANG Zhipeng;ZHANG Kaizhang;WU Fei(Road and Bridge Engineering Department,Inner Mongolia Vocational and Technical College of Communications,Chifeng 024005,China;Scegc Mechnized Construction Group Company Ltd,Xi′an 710032,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]内蒙古交通职业技术学院道路桥梁工程系,内蒙古赤峰024005 [2]陕西建工机械施工集团有限公司,陕西西安710032 [3]北京交通大学土木建筑工程学院,北京100044

出　　处：《混凝土》2024年第4期67-70,127,共5页Concrete

基　　金：国家自然科学基金(51878031)。

摘　　要：目前针对碳纤维轻骨料混凝土在高温作用后的力学性能研究匮乏,考虑到火灾伴随的冲击和爆炸荷载对结构的破坏,采用直径74 mm的分离式霍普金森压杆(SHPB)装置,对轻骨料混凝土(LWAC)进行了动态压缩试验,研究了温度和碳纤维含量对LWAC动态压缩性能的影响,并通过SEM扫描电镜揭示了高温对LWAC微观结构的影响。结果表明:碳纤维掺量的增加提高了LWAC的静态抗压强度,而高温对其静态抗压强度具有劣化作用,纤维的掺入能够在一定程度上阻止高温强度劣化。LWAC的应力-应变曲线随着温度的升高趋于扁平,动态抗压强度降低而峰值应变和极限应变增大,动态抗压强度、峰值应变和极限应变随着碳纤维掺量的增加均出现先增大后减小的趋势。不同温度作用和碳纤维掺量下LWAC试样的DIF随应变率的增加呈线性增加,普通LWAC试件比碳纤维LWAC试样的速率敏感性更高。高温最初改善了LWAC的内部微观结构,但随着温度持续升高,试样内部微观结构严重劣化。There is a lack of research on the mechanical properties of carbon fiber reinforced lightweight aggregate concrete after high temperature.Considering the damage to the structure caused by the impact and explosion load accompanied by fire,the dynamic compression tests on lightweight aggreg ate concrete(LWAC)were carried out by using split Hopkinson pressure bar(SHPB)device with a diameter of 74 mm.The effects of temperature and carbon fiber content on the dynamic compression performance of LWAC were researched,and the effect of high temperature on the microstructure of LWAC was revealed by SEM.The results show that the increase of carbon fiber content improves the static compressive strength of LWAC,while high temperature has a deterioration effect on the static compressive strength of LWAC,and fiber incorporation can prevent the deterioration of high temperature strength to a certain extent.The stress-strain curve of LWAC tended to be flat with the increase of temperature,and the dynamic compressive strength decreased while the peak strain and ultimate strain increased.The dynamic compressive strength,peak strain and ultimate strain all increased first and then decreased with the increase of carbon fiber content.The DIF of LWAC specimens increased linearly with the increase of strain rate under different temperature and carbon fiber content.The rate sensitivity of ordinary LWAC samples was higher than that of carbon fiber LWAC specimens.The high temperature initially improved the internal microstructure of LWAC,but with the continuous increase of temperature,the internal microstructure of the sample seriously deteriorated.

关 键 词：碳纤维 轻骨料混凝土 高温 SHPB DIF 微观结构 

分 类 号：TU528.572[建筑科学—建筑技术科学]