混凝土经历常温及-30～-120℃间冻融循环作用的受压变形性能试验研究

发布时间：2019-02-17 11:53

【摘要】：通过混凝土经历两种超低温冻融循环作用工况的试验,探究混凝土超低温冻融循环作用下的受压变形性能。结果表明,随冻融循环作用次数的增加,超低温冻融循环作用上限温度时,因冻融损伤的累积效应使混凝土的弹性模量和峰值应变分别呈下降和增大的变化趋势;而超低温冻融循环作用下限温度时,因混凝土孔隙水结冰作用明显、产生的影响对冲了冻融损伤的累积效应使混凝土的弹性模量保持不变或略有增长、峰值应变变小。超低温冻融循环作用导致的混凝土弹性模量损失与其降温引起的峰值应变增长量有良好的对应关系,而超低温冻融循环的上限温度是否回到常温对混凝土受压变形性能的影响则不大。这些可为可靠地设计LNG类储罐预应力混凝土结构提供依据。
[Abstract]:The compressive deformation behavior of concrete under ultra-low temperature freezing and thawing cycle was investigated through two kinds of tests under ultra-low temperature freezing and thawing cycle. The results show that, with the increase of freezing and thawing cycles, the elastic modulus and peak strain of concrete decrease and increase because of the cumulative effect of freezing and thawing damage at the upper temperature of freezing and thawing cycle at ultra-low temperature. However, at the lower temperature of freezing and thawing cycle at ultra-low temperature, the effect of concrete pore water icing is obvious, and the cumulative effect of freezing and thawing damage makes the elastic modulus of concrete keep constant or slightly increase, and the peak strain becomes smaller. The loss of elastic modulus of concrete caused by ultra-low temperature freeze-thaw cycle has a good relationship with the increase of peak strain caused by freezing and thawing. However, whether the upper limit temperature of ultra-low temperature freeze-thaw cycle returns to normal temperature has little effect on the compressive deformation performance of concrete. These can provide the basis for the reliable design of LNG type storage tank prestressed concrete structure.
【作者单位】：清华大学土木工程系;
【基金】：国家自然科学基金(51478242)
【分类号】：TU528

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