| 摘要 |
A cement mortar compsn. (a) has a ratio by wt. of cement: additives of 1:1.5-3.5 (1:1-5-2), (b) contains a dispersion of non-saponifiable or difficulty saponifiable resins, esp. acrylic resins, in a ratio by wt. of resin solids:cement of 2-25:1 (5-10:1), (c) contains de-foaming and/or thinning additives, (d) opt. contains pozzolana and/or fibres or fibrous materials, esp. of asbestos, glass or synthetics, and (e) has a water-cement value of 0.25-0.45 (0.40). The compsn. is applied to the inner surfaces of pipes, tubular articles and armatures of steel, cast iron, concrete or cement asbestos, by spraying a 1-5 mm (2-3 mm) layer by air press. onto a rotating, disc-like wheel and spreading the compsn. radially from the wheel. Uniform, smooth, thin layers can be applied economically inside pipes of any type. The layers are free from cracks, and firmly bonded, e.g. to bitumen or sandblasted cast iron. The layers are resistant to abrasion. Further treatment of the surface is not necessary. |
