摘要
为进一步提升工程材料的力学性能,选用端勾型钢纤维以及短切玄武岩纤维,基于现有研究中的优良掺量比,制备7组纤维掺量比混凝土试件,开展静态力学试验,探究2种纤维混杂效果并确定最优掺量比。采用大直径分离式霍普金森压杆、高速摄像装置以及数字图像相关法,针对最优掺量比,开展180、255、330、405、480 s^(-1)等5个应变率级别下的动态压缩试验,并对其动态增长因子进行非线性拟合。结果表明,劈裂抗拉强度和抗折强度的提升效果更加明显,最大可分别提升50%、49.4%,抗压强度最大仅提升12.7%;当玄武岩纤维体积掺量0.12%、钢纤维体积掺量1.5%时混凝土综合表现最优;动态抗压强度、峰值韧性等随应变率提高而增大,DIF与应变率以对数的指数形式呈抛物线型增长;裂缝多从左端应变集中处开始产生并均匀发展。
To further enhance the mechanical performance of engineering materials,both hook-ended steel fibers and chopped basalt fibers were selected,while based on optimal fiber dosage ratios from existing studies,seven groups of concrete specimens with different fiber ratios were prepared.Then,static mechanical tests were conducted to investigate the mixing effects of the two types of fibers and to determine the optimal fiber dosage.For this optimal fiber ratio,dynamic compression tests were performed at five different levels of strain rate(180,255,330,405 and 480 s^(-1))using a large-diameter split Hopkinson pressure bar(SHPB),high-speed camera and digital image correlation(DIC),and the dynamic growth factors was nonlinearly fitted.Results indicate that the improvements in splitting tensile strength and flexural strength are more significant,with maximum increases of 50%and 49.4%,respectively;the maximum enhancement of compressive strength was only 12.7%.The optimal performance of concrete was observed at a basalt fiber dosage of 0.12%and a steel fiber dosage of 1.5%.Both dynamic compressive strength and peak toughness increased with higher strain rates,and the dynamic increase factor(DIF)and strain rate exhibited a parabolic growth following a logarithmic exponential relationship.Cracks predominantly initiated at the strain concentration areas near the left end and developed uniformly.
作者
马芃晟
孙云厚
周丰峻
高航
MA Pengsheng;SUN Yunhou;ZHOU Fengjun;GAO Hang(Defense Engineering Institute,AMS,PLA)
出处
《防护工程》
2025年第3期71-78,共8页
Protective Engineering
基金
黑龙江省自然科学基金(YQ2022E018)
关键词
纤维混凝土
霍普金森压杆
钢纤维
玄武岩纤维
力学性能
fiber-reinforced concrete
split Hopkinson pressure bar
steel fiber
basalt fiber
mechanical property
