双掺膨胀剂和纤维的混凝土裂缝控制技术及应用研究

Research on Application and Crack Control Technology of Concrete Mixed with Expansive Agent and Fiber

为保障超长结构混凝土的无缝施工,研究了膨胀剂、聚丙烯纤维及两者双掺对混凝土力学性能、变形性能及早期抗裂性能的影响,并对实际工程进行了温度、应变监测。结果表明,聚丙烯纤维可以改善混凝土的力学性能、变形性能、早期抗裂性能;单掺膨胀剂可以改善混凝土的收缩变形;在实际工程应用中,采用双掺的裂缝控制技术制备的混凝土,收缩和早期抗裂性能均最优,且混凝土14 d后仍保持微膨胀状态,裂缝控制效果显著。

In order to ensure the seamless construction of super long structural concrete,the effects of expansive agent,polypropylene fiber and the addition of both on the mechanical properties,deformation properties and early crack resistance of concrete are studied,and the temperature and strain of practical engineering are monitored.The results show that polypropylene fiber can improve the mechanical properties,deformation properties and early crack resistance of concrete;while adding expansive agent alone can improve the shrinkage deformation of concrete.In practical engineering application,the concrete prepared with both polypropylene fiber and expansive agent by crack control technology has the best shrinkage and early crack resistance,and the concrete still maintains a micro expansion state after 14 days,and the crack control effect is remarkable.