钢纤维和膨胀剂对自密实混凝土增韧与阻裂效应

关键字：钢纤维,膨胀剂,自密实,劈拉强度,抗折强度,塑性开

（1.南京航空航天大学 航空宇航学院，江苏 南京  210016；2.连云港赣榆区墙体材料革新与建筑节能管理办公室，江苏 连云港  222199）

    摘要：采用高效减水、纤维增韧与微膨胀等技术，研究钢纤维与膨胀剂对自密实混凝土的增强、增韧和阻裂效应之间的相互关系。结果表明：钢纤维可显著提高自密实混凝土的劈拉抗折强度，且随着钢纤维掺量的增加呈线性关系；钢纤维和膨胀剂能有效抑制其早期与后期收缩开裂，在前期会产生轻微膨胀，达到一级抗裂等级，但后期会回落，360 d干燥收缩率小于100 με。
    关键词：钢纤维；膨胀剂；自密实；劈拉强度；抗折强度；塑性开裂；干燥收缩
    中图分类号：TU528        文献标识码：A        文章编号：1001-702X（2017）05-0050-03

Study of steel fiber and expansive agent on toughening and crack arrest of self-compacting concrete
LI Jin1，YANG Jie1，WU Chenghao1，YIN Gang2，YU Xuelan1，XIE Jianguang1，GENG Fei1
（1.Department of Civil Engineering，Nanjing University of Aeronautics & Astronautics，Nanjing 210016，China；2.Wall Materials Innovation and Building Energy Conservation Management Office，Ganyu District，Lianyungang 222199，China）

    Abstract：The effect of steel fiber and expansive agent on the strengthening，fiber toughening and crack arrest effect of self-compacting concrete were studied by the technology of high efficiency water reducing，fiber toughening and micro expansion. The results show that steel fiber can significantly improve the splitting tensile and flexural strength of self-compacting concrete，presented a linear relationship with the increase of content of steel fiber，steel fiber and expansive agent can effectively inhibit the early and latter shrinkage cracking，and had a slight expansion in the early，reached the first level of crack resistance，but fell in the latter. 360 d dry shrinkage rate less than 100 με.
    Key words：steel fiber，expansive agent，self-compacting，splitting tensile strength，bending strength，plastic cracking，drying shrinkage