● job practice:
1, construction machines and tools: sand coating mixer, extrusion grouting pump, air compressor, daub, cleaning, transportation tools, etc.
2. Construction preparation: (1) build scaffolding; (2) power and water; (3) remove the surface of tunnel concrete dust, oil, and wet water; (4) repair the uneven surface, and wipe the particularly smooth concrete surface with mortar; (5) leak to repair waterproof.
3, base construction: (1) ingredients, the paint and water to about 0.7 ratio, first add a small amount of water mixing side coating, and appropriate water, generally stirring 20min into thick slurry (must ensure the mixing time); (2) construction, with the spraying machine from the waist of the tunnel from the bottom to spray, each spraying 3-7mm thick, interval construction time above coating basic dry as the standard, so cycle, until spraying to the design thickness, after the last spraying, if smooth, with smear.
4, surface construction: (depending on the situation) in the basic base dry type after about three days, can carry out surface construction (for the requirements of high surface decoration of municipal engineering, it is best to scrape a layer of putty before the surface construction). The surface can be used spray gun, drum and other machinery construction spray brush must be smooth, uniform, no color difference. The color boundary line shall be straight and uniform.
5, maintenance: the construction is completed, the conventional natural maintenance for 28 days, the maintenance conditions are the same as the ordinary concrete, if the coating is damaged, it should be repaired in time.
matters need attention:(1) The validity period is six months, once the bag should be used immediately, the damp block coating shall not be used.
(2) When mixing, the slurry is too dry, so the water-cement ratio can be appropriately increased, and the appropriate construction shall prevail.
(3) scattered in the process of mixing construction, the rebound slurry can be recovered in time, contaminated and more than 2 hours of paint can not be used again.
(4) The construction method can be appropriately adjusted according to the design thickness and construction conditions of the coating.
