摘要
为了研究低温下泡沫混凝土的动态力学性能,采用∅100 mm的铝制分离式霍普金森压杆(SHPB)装置对不同温度下泡沫混凝土试件进行冲击压缩试验,得到了不同温度、应变率下的泡沫混凝土的应力应变曲线、能量参数、破碎形态等。结果表明:当应变率在62.59 s^(-1)以下时,泡沫混凝土应力应变曲线分为线弹性阶段、屈服阶段、破坏阶段;当应变率超过62.59 s^(-1)时,其应力应变曲线分为线弹性阶段、屈服阶段、局部失稳、应力平台、破坏阶段;常温、0℃、-10℃、-20℃和-30℃下,泡沫混凝土的动态抗压强度以及吸收能在对应的应变率分界点前表现出显著的应变率效应,但超出该分界点后,应变率效应便不再明显;泡沫混凝土的动态峰值抗压强度与吸收能随温度的降低而提高,但峰值应变随温度降低而降低;泡沫混凝土冲击破碎后的块度随着温度的降低逐渐变大。在低温环境下泡沫混凝土的抗动载设计中,对于泡沫混凝土的峰值抗压强度、吸收能,应优先考虑温度效应的影响,而对于其峰值应变,应优先考虑应变率效应。
In order to study the dynamic mechanical properties of foamed concrete at low temperature,a∅100 mm aluminum split Hopkinson pressure bar(SHPB)equipment was used to carry out impact compression tests on foamed concrete specimens at different temperatures.The stress-strain curves,energy parameters and crushing forms of foamed concrete at different temperatures and strain rates were obtained.The results show that when the strain rate is below 62.59 s^(-1),the stress-strain curves of foamed concrete are divided into linear elastic stage,yield stage and failure stage.When the strain rate exceeds 62.59 s^(-1),the stress-strain curves are divided into linear elastic stage,yield stage,local instability stage,stress plateau stage and failure stage.At room temperature,0℃,-10℃,-20℃and-30℃,the dynamic compressive strength and absorption energy of foamed concrete show significant strain rate effect before the corresponding cut-off point of strain rate,but the strain rate effect is not obvious after the cut-off point.The dynamic peak compressive strength and absorption energy of foamed concrete increase with the decrease of temperature,but the peak strain decreases with the decrease of temperature.The lumpiness of foamed concrete after impact becomes larger with the decrease of temperature.In the dynamic load resistance design of foamed concrete under low temperature environment,the influence of temperature effect is given priority to the peak compressive strength and absorption energy of foamed concrete,while the strain rate effect is given priority to the peak strain of foamed concrete.
作者
吴森宝
宗琦
王军国
汪海波
王梦想
贾虎
WU Senbao;ZONG Qi;WANG Junguo;WANG Haibo;WANG Mengxiang;JIA Hu(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China;Academy of Civil Engineering&Architecture,Nanyang Normal University,Nanyang 200125,China)
出处
《硅酸盐通报》
CAS
北大核心
2022年第1期76-87,共12页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(52074009)
安徽省自然科学基金(2008085ME163)
安徽理工大学研究生创新基金(2020CX2025)。
关键词
低温
SHPB
泡沫混凝土
温度效应
应变率效应
能量
low temperature
SHPB
foamed concrete
temperature effect
strain rate effect
energy
