纤维与膨胀剂对大掺量矿物掺合料混凝土塑性收缩开裂的影响

Effects of fibers and expansive agent on plastic shrinkage and cracking of concretes with high content mineral admixtures

采用平板限制收缩试验法,研究了聚丙烯纤维、钢纤维与膨胀剂及其复合技术对大掺量矿物掺合料混凝土早期塑性收缩开裂的影响。结果表明,大掺量矿物掺合料混凝土的早期抗裂性大小顺序为:纤维增强高性能膨胀混凝土>纤维增强高性能混凝土>混杂纤维增强高性能混凝土>混杂纤维增强高性能膨胀混凝土>高性能膨胀混凝土。因此,采用膨胀剂与钢纤维的复合技术是防止混凝土发生塑性收缩开裂的比较理想的技术措施。

With a slab test of restricted shrinkage, the effect of polypropylene fiber, steel fiber and expansive agent on early- age plastic shrinkage and cracking of concretes with high content mineral admixtures is investigated. The results show that the order from large to small of the early - age crack resistance of concretes with high content mineral admixtures is high performance expensive concrete with fiber 〉 high performance concrete with fiber 〉 high performance concrete with hybrid fibers 〉 high performance expensive concrete with hybrid fibers 〉 high peffomaance expensive concrete. Therefore, the technology combining steel fiber with expensive agent is appropriate to the plastic shrinkage and cracking of concretes.