摘要
为了探讨不同水灰比混凝土冻融后动态力学性能的变化规律,配制水灰比(质量比)为0.4,0.45和0.5的三组混凝土,先后开展了冻融循环试验和动态冲击试验。冲击试验后收集破碎试样,利用筛分试验对其分形特征也进行了研究。试验结果表明:50次冻融循环后,混凝土的动态抗压强度显著降低;受应变率的影响,当提高冲击速率时,冻融后混凝土的动态抗压强度与静强度相比依旧有不同程度的增长。此外,筛分统计结果也表明混凝土试样的分形维数与冲击气压和冻融循环次数呈正相关关系。考虑到水灰比的影响发现,在相同的冻融循环和冲击荷载下,混凝土试样的动态力学性能随水灰比的增大而降低,而冲击破碎分形维数则随水灰比的增大而增大。
In order to explore the dynamic mechanical properties of concrete with different water cement ratio after freeze-thaw, three groups of concrete with water cement ratio of 0.4, 0.45 and 0.5 were prepared, and the freeze-thaw cycle test and dynamic impact test were carried out successively. Meanwhile, the broken samples were collected after the impact test, and their fractal characteristics were studied by screening test. The test results show that the greater the number of freeze-thaw cycles experienced by concrete samples, the smaller the dynamic compressive strength. The greater the impact pressure, the greater the dynamic compressive strength. In addition, the screening statistical results also show that the fractal dimension of concrete samples is positively correlated with the impact pressure and the number of freeze-thaw cycles. Considering the influence of water cement ratio, it is found that under the same freeze-thaw cycle and impact load, the dynamic mechanical properties of concrete samples decrease with the increase of water cement ratio, while the fractal dimension of impact fracture increases with the increase of water cement ratio.
作者
黄子辰
薛刚宏
吴开侠
朱大亮
梁帅锋
Huang Zichen;Xue Ganghong;Wu Kaixia;Zhu Daliang;Liang Shuaifeng(Bureau of Public Works of Shenzhen Municipality,Shenzhen 518000,China;China Construction Science and Industry Corporation Ltd.,Shenzhen 518000,China)
出处
《山西建筑》
2023年第4期104-108,共5页
Shanxi Architecture
基金
中建科工技术研发项目(NO.ZJKG/HN/2021-026/FBHT/JSZX-01)。
关键词
混凝土
力学性能
破碎分形
冻融循环
冲击荷载
水灰比
concrete
mechanical propeties
broken fractal
freeze-thaw cycles
impact load
w/c
