超长混凝土结构膨胀加强带补偿收缩纤维混凝土的性能研究

摘要

Concrete mix proportion of shrinkage compensating concrete was designed according to the requirement of super-length concrete structure in Pudong Tobacco Science and Technology Park. Shrinkage compensating concrete can be divided into three kinds of compressive grades which is C35、C40、C45 used inside and outside the expansion reinforcing band respectively. Limited expansion ratio and compressive strength variety of shrinkage compensating concrete to different expansion agent content was discussed,while the influence of organic fiber to cracking performance of concrete at early age was also researched. The re-sults show that limited expansion ratio,compressive strength and cracking performance at early age of shrinkage compensating con-crete reached the best level when the expansion agent content controlled in a narrow range of 35~40 kg/m3 and polypropylene fiber content was 0.6 kg/m3.%根据烟草浦东科技园区超长结构工程要求,设计了膨胀加强带带内、带外的C35、C40、C45补偿纤维收缩混凝土配比,研究了膨胀剂掺量为35、40、45 kg/m3时,各强度等级补偿收缩纤维混凝土限制膨胀率和抗压强度的变化情况,并研究了有机纤维种类对补偿收缩混凝土早期抗裂性能的影响.结果表明:膨胀剂掺量为35~40 kg/m3、聚丙烯纤维掺量为0.6 kg/m3时,补偿收缩混凝土的限制膨胀率、抗压强度、早期抗裂性能指标达到最佳.