| 不同超低温温度区间冻融循环作用混凝土受压强度试验研究 |
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| 引用本文： | 时旭东,李亚强,李俊林,汪文强,钱磊.不同超低温温度区间冻融循环作用混凝土受压强度试验研究[J].工程力学,2020,37(4):153-164. |
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| 作者姓名： | 时旭东 李亚强 李俊林 汪文强 钱磊 |
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| 作者单位： | 清华大学土木工程系, 北京 100084 |
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| 基金项目： | 国家自然科学基金项目(51878375,51478242)。 |
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| 摘 要： | 通过混凝土经历3种温度区间（10~℃-40℃、10~℃-80℃和10~℃-160℃）的冻融循环作用试验，探讨不同的超低温温度作用区间对混凝土受压强度的影响。结果表明:经历不同超低温温度区间各种冻融循环作用次数的试件，上下限温度时加载的破坏形态虽基本上呈对顶锥状，但其破坏过程声响和破坏状况等不尽相同；经历超低温冻融循环作用混凝土的受压强度变化规律明显不同于遭受自然环境温度下冻融作用，各超低温温度区间的冻融循环作用影响也不同。下限温度较高温度区间的冻融循环作用初期，混凝土受压强度将提高，但之后随冻融循环作用次数的增加呈波动状的恶化态势；不同超低温温度区间的混凝土单次冻融循环作用损伤指标和累积冻融循环作用损伤指标存在明显的差异。对于下限温度较高的温度区间，下限温度时它们经历较多次冻融循环作用后仍为正值，而下限温度较低的温度区间则经历数次冻融循环作用后便始终为负值，表明混凝土累积损伤较前者严重。这些结果可为可靠地进行液化天然气储罐类混凝土结构设计提供参考。
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| 关 键 词： | 混凝土 超低温 冻融循环作用 温度区间 受压强度 |
| 收稿时间： | 2019-07-01 |
EXPERIMENTAL STUDY ON THE COMPRESSIVE STRENGTH OF CONCRETE UNDERGOING FREEZE-THAW CYCLE ACTIONS WITH DIFFERENT ULTRALOW TEMPERATURE RANGES |
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| SHI Xu-dong,LI Ya-qiang,LI Jun-lin,WANG Wen-qiang,QIAN Lei.EXPERIMENTAL STUDY ON THE COMPRESSIVE STRENGTH OF CONCRETE UNDERGOING FREEZE-THAW CYCLE ACTIONS WITH DIFFERENT ULTRALOW TEMPERATURE RANGES[J].Engineering Mechanics,2020,37(4):153-164. |
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| Authors: | SHI Xu-dong LI Ya-qiang LI Jun-lin WANG Wen-qiang QIAN Lei |
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| Affiliation: | Department of Civil Engineering, Tsinghua University, Beijing 100084, China |
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| Abstract: | Through freeze-thaw cycle action experiments of concrete with ultralow temperature ranges of 10℃ to -40, 10 to℃℃ -80 and 10 to℃℃ -160,℃ the effect of different ultralow temperature ranges on the concrete compressive strength is investigated. From these test results, it can be shown that for the specimens undergoing various freeze-thaw cycles at different ultralow temperature ranges, their failure modes are basically in a double cone shape when they are loaded at upper and lower limit temperatures. But the sound during their destruction processes and failure conditions are different. The variation regularity of the compressive strength of concrete undergoing freeze-thaw cycle actions under ultralow temperatures is obviously different from that at natural environment temperature. The effect of the freeze-thaw cycle action for various ultralow temperature ranges on the concrete compressive strength is also different. The concrete compressive strength will increase at the initial stage of the freeze-thaw cycle action for these temperature ranges with the lower limit temperatures which are relatively higher. After that, they fluctuate and trend to a deteriorating state with the increase in number of freeze-thaw cycles. There are obvious differences among different ultralow temperature ranges for the single freeze-thaw cycle action damage index and the cumulative freeze-thaw cycle action damage index of concrete. For the temperature ranges with the lower limit temperatures which are relatively higher, they are still positive after experiencing more freeze-thaw cycles at lower limit temperatures, but are always negative after several freeze-thaw cycles for those with the lower limit temperatures which are relatively lower. It shows that the cumulative damage of concrete due to the freeze-thaw cycle action for the latter is more severe than that for the former. The results in this paper can provide references for reliably designing concrete structures of liquefied natural gas storage tanks and so on. |
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| Keywords: | concrete ultralow temperature freeze-thaw cycle action temperature range compressive strength |
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