It can withstand hydrostatic pressure up to 0.5 ... 0.6 MPa. Plaster waterproofing compositions include:
• cement-sand mortars with various sealing additives;
• polymer-cement and glass-cement solutions;
• gunning from colloidal cement mortar;
• fine-grained asphalt concrete (asphalt plastering waterproofing).
Cement-sand insulation in its pure form is used extremely rarely, usually it is combined with painting or glue waterproofing. The reliability of plaster insulation will increase significantly when reinforced with metal mesh and glass cloth materials (Figure 19.3).
In other cases, waterproof nonshrinkable cement or portland cement with sealing additives — ceresite, ferric chloride, liquid glass, sodium aluminate, bitumen and latex emulsions are used for plastering waterproofing. Pure sand is used in the solution.
Fig. 19.3. Plastering 1-insulated structure; 2 - primer layer; 3 — plastering waterproofing; 4-metal mesh; 5-anchor | with a minimum grain size of 1.5 mm. The thickness of the waterproofing layer is set in the project and is within 5 ... 40 mm. The preparation of cement solution with the addition of ceresite is carried out in the following sequence; prepare a dry mixture of 1 mass, h of cement and 2 ... 3 parts of fine sand; This mixture is closed with ceresite milk (10 parts of water is taken for one part of ceresite) and adjusted to the consistency of a usual plaster solution. The solution is applied to the prepared surface with a layer of 2-4 cm, depending on the design pressure of water. The resulting surface is fermented with cement mortar (without sand), mixed with ceresit milk. Ferric chloride in an amount of 3% by weight of cement during setting of the solution forms a hydrate of iron oxide, which clogs the pores of the cement stone and makes the surface almost impenetrable. |
Liquid glass - 2.5% of the mass of cement makes the insulation after grouting and pressure ironing. And the coating of such insulation in three layers with liquid glass over hardened cement plaster leads to the formation of waterproofing suitable for reinforced concrete tanks.
Cement-sand insulation with the addition of 5% latex becomes increased
Fig. 19.4. Plastering waterproofing of pipeline passageways: 1-metal clamp; 2 plasters waterproofing; 3-fiberglass; 4 ceramic tiles; 5-insulated structure; 6 piping | elastic, but the strength of the coating is almost halved, so you have to use a higher grade of solution. On a solution of composition from 1: 1 to 1: 3, the insulation is durable, no protective coating is required from mechanical damage, the solution is easily applied manually and by means of mechanization. The resulting insulation is easy to repair and restore. The total insulation thickness is 2 ... 2.5 cm. When applying plaster insulation by gunning with the use of cement guns, at least two layers of insulation are usually applied. Two layers of insulation with a total thickness of 25 mm withstand hydrostatic pressure 10 m, three layers with a thickness of up to 30 mm - up to 20 m |
When the insulated surfaces are subjected to brief periodic moistening (sanitary facilities, bathrooms, kitchens, utility rooms, canteens), the pipeline passageways are reinforced with fiberglass with plaster insulation and fixed at a height of at least 120 mm from the floor level (Fig. 19.4). For greater strength and a smooth surface, in all cases of plastering, ironing is performed.
Technology devices plaster waterproofing. The device of plaster insulation includes the preparation of surfaces, the strengthening of places of possible deformations, the application of plaster insulation compositions, measures to prevent the waterproofing layer from slipping on vertical and inclined surfaces.
Surface preparation consists of cleaning, leveling and drying to the desired humidity. Places in which deformation of insulated structures is possible (mates, fragile, niches, etc.) are reinforced with a pre-installed metal mesh, as well as fiberglass, laid in the process of applying plaster insulation.
To increase the reliability of adhesion of the plaster layer to the insulated surface, it is prepared: cut down the concrete inflows, make notches, glossy surfaces are sandblasted, then the surfaces are dedusted, the surface is washed and dried.
Cement-sand plaster insulation is applied, as a rule, by a mechanized method using plastering-troweling machines, and only with small amounts of work and in inconvenient places - manually. Cement guns, mortar pumps and plastering machines have been widely used for mechanized deposition of cement-sand compositions. The technology of applying plaster to the surface will be discussed in a separate topic.
A type of plaster insulation is cement gunning, which allows to mechanize the coating process and increase its reliability. Often used activated colloidal cement mortar, which is applied using a cement gun, maintaining the pressure of compressed air in the range of 0.25 ... 0.3 MPa. The dry mixture is supplied to the insulated surface pneumatically through the rubber 
Nevyi sleeves from cement guns, in which the mixture is dosed with dish-fed feeders. The dry mix is mixed with water in a plaster nozzle, where water flows through a separate rubber-fabric sleeve, equipped with a metering valve.
The nozzle is moved at a distance of 50 cm from the surface in a circular motion, thus achieving a more even application of the stucco. It is not recommended to wipe the freshly applied layer of activated gunning, as this leads to a violation of the density of the structure and adhesion to the base. The smooth surface of the plaster insulation is obtained by applying an additional layer 4 ... 5 mm thick from the composition containing fine quartz sand. In this case, the upper layer smooth down to its setting. Vertical surfaces are insulated from bottom to top in stripes 80 ... 100 cm wide to the full height, the length of the grab is within 20 m.
The technology of applying layers of gunning with their reinforcement with chopped fiberglass has found application. After applying a layer of solution, sprayed fiberglass fibers are sprayed into a freshly laid layer of the solution. The performance of the coating increases when 10% latex is added to the composition. The total thickness of the coating reaches 8 ... 10 mm and is characterized by high crack resistance and strength.
After applying the cement-sand mortar plaster insulation, it is painted with bitumen varnishes and emulsions, which form a waterproof layer on the surface and create a favorable mode for hydration processes.
With the coincidence of requirements for ensuring water resistance and high-quality decorative finishing of the room, the surfaces are coated in shower, bathtubs, and laundry tiles with plaster, solutions with increased moisture-tightness.
Insulation can be done from two sides. In the presence of water pressure, it is better that the insulation works in compression, rather than in tearing. If it is decided to arrange insulation from the inside, then from the outside, from the side of the surface in contact with water, a clay lock is arranged, i.e. a layer of compacted clay with a thickness of at least 20 cm over the entire plane of the insulated surface
The reliability of plastering waterproofing is directly dependent on the rigidity of the insulated surfaces and the impact of water. Therefore, the reliability of this type of insulation is due not only to the rigidity of the foundation, but also to the termination of the sediment structure and the absence of any vibrations.
Что бы оставить комментарий войдите
Комментарии (0)