摘要
研究了不同钢纤维体积分数(0、2%、3.5%)的超高性能混凝土(UHPC)在密封养护条件下的线性收缩量、温度变化以及水化放热速率随时间的变化规律。结果表明,超高性能混凝土的自收缩过程可以分为四个阶段,分别由温度和湿度控制,且与温度变化以及水化放热数据匹配良好;钢纤维的掺入不改变收缩发展阶段也不改变各阶段的持续时间,但随着钢纤维掺量的提高,有效抑制了UHPC收缩发展程度;通过MANGAT&AZARI纤维收缩抑制模型模拟UHPC自收缩变化,与实测数据的匹配度良好。
The linear shrinkage deformation, temperature and hydration release rate evolution in ultra-high performance concrete(UHPC) with different volume fractions of steel fibers(0, 2.0% and 3.5%)were studied. The results indicate that four distinct stages are identified on the shrinkage development profile governed by temperature and pore humidity, both of which possess good correlation to shrinkage strain. The addition of steel fibers does not alter the shrinkage pattern in UHPC and reduces shrinkage strain in proportion to the volume fraction of steel fibers. The MANGAT&AZARI model on shrinkage restraining effect is employed to calculate the shrinkage strain in steel fiber reinforced UHPC mixes, which demonstrates good match to the measured results.
引文
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