粉煤灰对高温后UHTCC试块抗折强度的影响

Effect of fly ash on mechanical properties of ultra high toughness cementitious composite exposed to high temperature

对控制不同粉煤灰含量的超高韧性水泥基复合材料(UHTCC)的高温后残余力学性能进行了实验研究,探讨了控制粉煤灰变量下高温对于其抗折强度以及质量损失率的影响,并就劣化机理进行分析。研究结果表明:粉煤灰含量对于质量损失无明显影响,而高温后粉煤灰含量对抗折强度损失有一定的影响,在200℃之前,粉煤灰含量较少组抗折强度损失率为7.5%,粉煤灰含量较多组抗折强度损失率为2.7%;400℃到600℃之间,高粉煤灰含量有效提高抗折强度;800℃后高粉煤灰含量组抗折强度损失明显,粉煤灰含量的增加可以在一定程度上提高UHTCC高温后的力学性能。

In this study, high volumes of fly ash （FA） effect on the residual properties of ultra high toughness cementitious composite （UHTCC） was investigated on the specimens exposed to high temperatures up to 800 ℃ , including mass loss ratio and residual rupture strength. The result showed that residual rupture strength was seriously effected. Before 200. ℃ , the loss rupture strength ratio of specimen which has the lower volumes of FA and the other specimen which has the higher volumes of FA were respectively 7.5% and 2.7 %, and the high volumes of fly significantly increase the rupture strength after 400℃ to 600 ℃ .After 800℃, the loss of rupture strength of specimen which has the lower volumes of FA was significant. The increasing amount of FA can improve the mechanical properties to some extent.