摘要
高延性混凝土(HDC)具有良好的拉伸应变-硬化特性和裂缝控制能力,受拉状态下产生多条细密裂纹,这使得HDC极有可能具有良好的抗冻性能。基于此,通过采用快速冻融方法对21个HDC试件进行了冻融循环试验来研究HDC的抗冻性能,其中,3个HDC棱柱体试件进行冻融循环试验,18个HDC立方体试件进行不同冻融循环次数下单轴受压试验,测定不同冻融循环次数作用后HDC的表观特征以及各项基本力学性能,包括极限承载力、动弹性模量、峰值应变和裂缝状态。试验结果表明,经过300次冻融循环后HDC具有良好的裂缝控制能力,试件出现较少的细密裂纹,表现出良好的抗冻性能。通过分析HDC冻融试验应力-应变曲线,得到HDC冻融本构关系曲线,且与试验曲线对比,发现本构模型曲线与试验曲线较为吻合。
High ductile concrete(HDC) has good tensile strain-hardening properties and crack control ability, and many fine cracks produce under tension, which makes it possible that HDC has good frost resistance. Based on this, 21 HDC specimens were tested by rapid freezing-thawing method to study the freezing-thawing resistance of HDC. Among them, 3 HDC prism specimens were tested by freezing-thawing cycle, 18 HDC cube specimens were tested under uniaxial compression under different freezing-thawing cycles, and the apparent characteristics and basic mechanical properties of HDC after different freezing-thawing cycles were measured, including ultimate bearing capacity, dynamic elastic modulus, peak strain and crack state. The test results show that after 300 freezing-thawing cycles, HDC has good crack control ability, and there are fewer fine cracks in the specimens, showing good frost resistance. By analyzing the stress-strain curve of HDC freezing-thawing test, the constitutive relation curve of HDC freezing-thawing test is obtained, and constitutive relation model curve is in good agreement with the experimental curve.
引文
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