Formwork is manufactured in accordance with the standards or specifications for specific types of formwork. During the construction of monolithic structures of residential and public buildings need high quality surface, and therefore to the formwork have additional requirements. Deformability of the casing depends on the strength and quality of the monolithic structures, as well as the complexity of shuttering and finishing works durability and cost of the formwork. In addition to a curved surface, violations of the geometric dimensions and other abnormalities in stiff enough formwork shell formed on the surface and air bubbles in compacting concrete. Decking the walls and pillars important requirement is to mold a uniform deformation of the functional purpose (for example, large-sized panels of the walls or ceilings). Heat treatment concrete formwork thermo-activated to consider the additional stress and strain upon heating formwork. In the building of solid structures to seal concrete, vertical structures are usually used internal vibrators. The use of external vibrators can reduce labor costs for concrete works.
However, much heavier formwork and also decreases the quality of concrete surfaces due to sucking air in vibration. All connections are shuttering is recommended to quick, they must be sufficiently dense and impenetrable. Welds, and sharp corners and edges of formwork shall be processed. Accuracy class formwork must be mounted on a class above the class of accuracy concreted structures, and the class of precision manufacturing of formwork shall be assigned to a class higher than the accuracy of installation. Class accuracy concreted structures prescribed in the project in accordance with GOST 21779-82. To build a monolithic structures with surfaces prepared for painting or wallpapering, you should use the formwork, which provides obtaining concrete surfaces on SNIP 3.04.01-87. Higher tolerances prescribed for the thermo-activated formwork, as apart from additional strains should be considered when sizing cooling and heating.
Most construction formwork made on the 7th class of accuracy. Universal formwork system designed for long life, high rate of turnover and use in different conditions must be met by more high precision. It should be borne in mind, however, that the overstatement of the precision of unjustified increases significantly the cost of formwork. Significant impact on the quality of the surface has a surface formwork in contact with the concrete. Good surfaces are obtained by applying a layer of grease on the metal casing. Decking from specially selected timber can, in some cases to get a nice texture. Good results give special absorbent lining. By increasing the absorption of the material decreases the number of pits and voids on the surface of the concrete. The different degrees of absorption leads to the lining appearance of clearly visible dark and lighter spots on the surface of the concrete. In addition, repeated application of the formwork also changes the degree of absorption and color of the concrete surface. Also change the color of concrete technology laying and compaction method. Beautiful formwork concrete surface can be obtained by using hardboard and plywood, covered with grease. Surface in this case is somewhat better than metal surface casing. Formwork with a completely impervious surface is often the cause of cavities and shells. In order to reduce their need to spend more emulsion lubricant. For these reasons, desirable to use a lubricant and for surfaces with little adhesion to concrete (plastic casing, plastic-coated plywood)