苏通大桥超薄防裂抗渗桥面调平层混凝土配制与施工

Concrete Preparation and Construction on Ultrathin and Anti-cracking Anti-permeability Leveling Course in Sutong Bridge

苏通大桥部分桥面调平层超薄,决定采用高性能混凝土并掺入聚丙烯纤维的技术措施,解决超薄调平层混凝土易开裂、抗渗性差等技术难题。通过砂浆、混凝土抗开裂试验确定混凝土中聚丙烯纤维种类,同时采取优选混凝土原材料和优化混凝土配合比的技术措施,结合试验段对施工工艺的不断改进和完善,确定高性能聚丙烯混凝土正式施工工艺,详细介绍抛丸处理箱梁表面,铺设网片,安装振捣轨道梁,喷雾润湿箱梁等工艺措施。现场检测表明,混凝土未出现裂纹,且抗渗性良好,达到了预期效果。

Because of the ultrathin leveling course in Sutong Bridge, high performance concrete with polypropylene fther is applied to solve some technique problems of easily cracking and worse impermeability. The kind of polypropylene fiber is assured through mortar and concrete anti-cracking experiments. Meantime, the technology methods of optimizing concrete raw materials and mix proportion, combining with improving construction technology in experimental section, are adopted to assure final construction technology of high performance polypropylene fiber concrete. The technology methods of throwing pill management for box girder faces, laying netting, installing vibrating track beam, spraying for wetting box girder are introduced in detail. The detecting results show that concrete has no cracks and has excellent impermeability.