基于CT试验的高强高性能混凝土高温下孔隙分析  

Pore analysis of high strength and high performance concrete at high temperature based on CT test

作　　者：陈薇[1] 杜红秀[1] CHEN Wei;DU Hongxiu(College of Architecture and Civil Engineering,Taiyuan University of Technology,Taiyuan 030024,Chin)

机构地区：[1]太原理工大学建筑与土木工程学院,山西太原030024

出　　处：《混凝土》2018年第6期6-8,12,共4页Concrete

基　　金：国家自然科学基金(51478290)

摘　　要：为探讨高强高性能混凝土高温爆裂机制,基于CT扫描技术,对掺与不掺聚丙烯纤维的C80高性能混凝土高温下内部孔隙的发生、发展、劣化过程进行研究,并利用计盒法估算孔隙分形维数。CT切片分析表明:随着温度升高,C80混凝土内部孔隙面积、数量总体呈增大趋势,掺0.2%聚丙烯纤维混凝土的孔隙劣化较素混凝土快;素混凝土(除300℃外)、掺0.2%聚丙烯纤维混凝土的各孔径范围内孔隙数量总体增大,在此过程中,10~20μm孔径的孔隙数量始终占比最大;分形维数总体均呈增大趋势,掺0.2%聚丙烯纤维混凝土的分形维数增幅较素混凝土大;素混凝土的分形维数在400℃前小幅增加,400℃后增加明显,掺0.2%聚丙烯纤维混凝土的分形维数在500℃后增加显著;分形维数的变化情况与混凝土内部孔隙劣化规律一致。In order to study the mechanism of high strength and performance concrete bursting at high temperature, pore of C80 highperformance concrete mixed with and without polypropylene fiber were analyzed, and the fractal dimension of the pore is estimated bythe box counting.CT analysis show that with the increase of temperature, the area and amount of internal pore of HPC0 and PPHPC in-creased, and pore deterioration in PPHPC is faster than HPC0.The total number of pores in the range of pore size of HPC0 （except 300℃）and PPHPC increases, In this process, the number of pore sizes between 10 and 20 滋m is always the largest.The fractal dimensionincreases, and PPHPC grows faster.The fractal dimension of HPC0 increases slightly before 400 ℃, and increases obviously after 400℃, PPHPC increased significantly after 500 ℃.The change of the fractal dimension with the temperature can reflect the pore deteriora-tion of the concrete.

关 键 词：C80高性能混凝土 聚丙烯纤维 高温 孔隙 分形维数 

分 类 号：TU528.01[建筑科学—建筑技术科学]