超低温环境下混凝土本构关系试验研究

EXPERIMENTAL RESEARCH ON THE CONSTITUTIVE RELATIONSHIP OF CONCRETE IN A CRYOGENIC ENVIRONMENT

  • 摘要: 针对超低温下混凝土本构关系进行试验研究,通过对试验数据整理分析,得出在20℃、0℃、-40℃、-80℃、-120℃、-160℃六个温度点下的应力-应变全曲线。该试验以抗压强度、弹性模量、峰值应变为主要测试指标。试验结果表明,试验温度越低,试件的破坏越迅速,测得的应力-应变全曲线下降段越短且越陡峭。随着温度降低,混凝土的峰值应变减小,脆性增大,强度与弹性模量均有所提高,且各自的提高程度与温度有关,全曲线的上升段与下降段可以用三次多项式与有理式分别拟合。

     

    Abstract: To develop a concrete constitutive relationship under cryogenic conditions, stress-strain curves were developed by sorting test data from the following temperature conditions: 20℃, 0℃, -40℃, -80℃, -120℃, -160℃. Compressive strength, elastic modulus, and peak strain were taken as key indicators in this test. The test shows that specimens are damaged more quickly at lower temperatures, and the descending branch of the curve is shorter than in normal conditions. Moreover, the lower the temperature, the shorter and the steeper the descending branch becomes. From the results, we can conclude that the concrete peak strain drops with decreased temperature, meaning the brittleness tends to increase. Both the compressive strength and elastic modulus increase, but the respective improvement of their performance has to do with the temperature. A third-order polynomial and a rational expression are proposed to describe the rising branch and descending branch, respectively.

     

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