纳米高分子减水剂提高喷射混凝土功效应用技术

Application Technology of Nano Polymer Water Reducing Agent to Improve the Efficiency of Shotcrete

针对传统外加剂喷射混凝土回弹大、速凝剂超耗、易堵管、喷射时间久的问题,结合本工程特点,笔者在新建玉溪至磨憨铁路施工时,在喷射混凝土中加入纳米高分子减水剂,利用高分子减水剂的物理化学作用机理,采用湿喷工艺,将隧道初期支护的喷射混凝土回弹量降低到5%,将喷射混凝土成本每方降低130元左右,同时每喷射循环降低喷射时间1.5小时左右,解决材料不稳定造成喷射混凝土堵管问题,大大提高经济效益,并节省喷射时间,提高工程质量、进度。

In view of the problems of traditional admixture sprayed concrete, such as, large-scale rebound, super-coagulant super-consumption, easy blockage, long injection time, and so on, combined with the characteristics of this project, the author added nano polymer water reducing agent to the sprayed concrete during the construction of the new Yuxi-Muhan railway. The physical and chemical action mechanism of the polymer water reducing agent is used and the wet spraying process is applied to reduce the amount of shotcrete rebound of the initial support of the tunnel to 5% and reduce the cost of the shotcrete by about 130 yuan per side, and at the same time, the injection time is reduced by about 1.5 hours per injection cycle, which solves the problem that the material instability causes the sprayed concrete to block the pipe, greatly improves the economic benefit, saves the injection time, and improves the project quality and progress.