Moisture-proof materials are called to protect structures from a constant action of aggressive moist medium, most frequently under the pressure of water. In connection with this, the materials of this group must be characterized by such properties as waterproofness, water resistance, longevity, and also satisfy the requirements on the mechanical strength, deformation, chemical stability and so forth

The fields of application of moisture-proof materials are varied: these are the external and internal protection of underground structures, waterproofing underwater, water-engineering constructions, weirs, supports of bridges, embankments, ponds, reservoirs, reservoirs.

Waterproofing not only protects the protected surface from the contact with the water, but also ensures [parogidroizolyatsiyu], increases the resistance of structure to corrosion.

The application of moisture-proof materials began in extreme antiquity. Still 4500-5000 years ago natural bitumen, resins were used as the binding and moisture-proof materials with the construction of Egyptian and babylonian facilities. And at our days artificial (most frequently [neftebitumnye]), natural bitumens and materials with their use are one of the most [upotrebimykh] reliable moisture-proof materials. However, the serious competitors of the [bitumosoderzhashchikh] materials are synthetic resinpolymers and materials on their basis.

Moisture-proof materials are subdivided about the sign of physical state and the external view of:

• mastic;
• powder, solutions;
• roll, sheet;
• tape, [polimermembrannye];
• other forms.

Pastes - these are the viscoplastic masses, obtained by the mixing of the organic binding agents for the sake of the finely dispersed fillers and by the special additives, which possess the pasting ability. Before their properties and technology the preparations of paste differ little based on the glues and only increased viscosity and significant content of fillers serve after base for the reference of this glue composition to the discharge of the pastes (glue- adhesives and sealing compounds in this chapter they are not examined).

Pastes - these are the glue compositions, which not only connect different materials between themselves, but also cover the surfaces of components and constructions sufficiently thick layer for their protection from the corrosion, are filled slots, shells, openings and other deepenings in order to obtain uniform smooth surface or to ensure the airtightness of seams. They use as the coating waterproofing, for pasting of surfacing materials to the walls, to sexes, for gluing of roll materials.

For the roofing and moisture-proof works hot and cold pastes on the basis of oil asphalt traditionally are used. Hot bitumastics are the mixture of the alloy of roofing bitumens for the sake of the fibrous or powdered fillers.

For an improvement in the properties of bitumastics beside their composition the rubber crumb of worked out rubber is introduced. Such pastes were called bituminous- rubber.

Are promising hot pastes on the basis of petroleum bitumen and low-molecular (atactic) of polyethylene or polypropylene. [Polimerbitumnye] pastes have high thermal stability, elasticity, cementing properties.

Powder waterproofing

Powder moisture-proof materials are prepared on the basis of the cement synthetic resins binding with the addition and high-quality plasticizers, regulators of hardening and so forth these materials are supplied for building in the form of dry mixtures, close by water on the spot of the carrying out of works, they are convenient before the preparation and do not require complex equipment for their putting beyond the protected surfaces.

The long-standing scientific research works, carried out before Russia and abroad, made it possible to master and to propose to user many new [vysokoefektivnykh] composition moisture-proof materials.

Penetrating waterproofing

Penetrating waterproofing - this reliable guarantee of a waterproofness of concrete constructions.

The properties of this material consist before the fact that the components of material, substituted down the concrete surface, they penetrate inside the concrete concerning its times and capillary circuits even against the high hydrostatic pressure. As a result the active chemical reaction between the components of material and the components of concrete itself are formed crystal structures, by their composition similar down the concrete.

These formations, tightly filling for the sake of themselves all times and microspaces, [uplotnyayut] the structure of concrete, ensuring, thus, reliable waterproofness.

Crystalline formations, without passing water, do not at the same time prevent the movement of air, making possible at the point of concrete “to breathe”.

The constructions, processed by this material, resist the action of the majority of aggressive media, preventing corrosion and penetration of undesirable chemicals beside the environment. Material is inert, it does not contain solvents and it does not separate evaporations. The life of material is equal down the period of life of concrete itself.

Processed by a similar material the concrete constructions:

• they are waterproofed;
• they are resistant down the aggressive media;
• have the best strength characteristics;
• are more frost-resistant;
• dry surface is not required;
• priming and levelling off of surface is not required;
• protection during filling in and arrangement of metal insert is not required;
• are not terrible perforations, detachments or separations from surface.

Tape, [polimermembrannye] moisture-proof materials

The tape, [polimermembrannye] roll moisture-proof materials are well known, for example, polyethylene film. These materials are characterized by resistance to aggressive media, longevity, strength, elasticity. They adapt before the antifiltration devices. Domestic polyethylene films have a thickness of 0,2-0,4 mm. foreign, so called, geo-membrane - 0,2-1 mm.