矿物掺合料对箱梁混凝土长期变形性能的影响研究

Study on influence of mineral admixtures on long-term deformation performances of concrete in box-girder

试验研究了矿物掺合料对箱梁混凝土长期变形性能的影响。结果显示:粉煤灰或矿粉掺入后,均降低了箱梁混凝土的自收缩及干燥收缩,且一定程度上抑制了箱梁混凝土的徐变变形,但在抑制徐变变形方面,矿粉掺量存在一临界值。复合掺合料的"超叠加"效用在改善混凝土徐变性能方面较为显著,在同等掺量的情况下,较单掺粉煤灰或单掺矿粉效果更佳。

The paper studies the influence of mineral admixture on the permanent deformation of concrete box girder and the results are displayed as follows：the existence of powder coal or mineral powder may lessen the self-shrinkage ability and the dry-shrinkage ability of the girder, while on the other hand contains any creep deformation to some extent. However, mineral powder has its limit in terms of deformation resistance. The amplification effect of multiple mixtures is fully displayed in terms of restraining the creep deformation of the concrete, as its performance largely exceeds that of one single mixture, be it powder coal or mineral powder.