Liquid dosage forms. Characteristics of local dosage forms and methods of their use Solutions Where solutions are used

The solution used for laying must have a certain amount of heat so that it does not freeze quickly and does not lose the necessary plasticity and workability. When using a heated mortar, the same thickness and density of the bed is created, as a result of which the pressure transfer from brick to brick will be uniform.
The heat reserve in the mortar must be sufficient for the time of its laying in place and its initial compression in the seam by the overlying bricks. If the solution is not heated, it quickly freezes, loses plasticity, freezes to the trowel and cannot be spread thin layer on brick: the seams are obtained with unequal thickness and density. When thawed, this will cause uneven masonry settlement and a decrease in its strength.
Materials and solutions. The temperature of the solution when laying it in the case should not be lower: + 10 ° - at an air temperature above - 10 °, + 15 ° - at a temperature from -10 to -20 ° and + 20 ° - at a temperature below -20 °.
The solution must be prepared necessarily in an insulated mortar plant or mortar unit.
Sand, brick and slag should be stored in piles under a canopy or covered from above with scraps of boards, waste roll materials, be sure to arrange drainage grooves to reduce the freezing of materials in winter. /
Before preparing the solution during severe frosts water is heated to a temperature of 80 °, and sand to 60 °. During mild frosts, tulko water is heated (this is easier and more economical, since the heat capacity of water is 5 times greater than the heat capacity of sand), and the sand is only thawed. Cement and lime do not heat up.
Used to heat water various devices depending on the required quantity and heat source. Most often, water is heated with steam, passing it directly into a vessel with water or through coils. Passing through the pipes of the coil, passed inside the vessel with water, the steam gives it its heat through the walls of the pipes. With a small flow of water, it can be heated by passing through a coil embedded in the hearth. With significant consumption, water is heated in special water-heating furnaces, arranged from finned pipes or radiators.
Sand is heated wet or dry. In the dry method, more often used in permanent mortar plants, pipes are laid in the sand bin and hot gases from the firebox are passed through them. In the wet method of heating the sand, steam is passed directly through the sand hopper or with a portable steam needle. Sand, when heated with steam, absorbs a certain amount of moisture, which should be taken into account when dosing water when preparing the solution.
When preparing a solution on heated water, sand and water should be loaded into the mortar mixer first, and only when the temperature of the mixture after mixing is equalized, cement is introduced.

Mortars for masonry. The composition of masonry mortars and the type of initial binder depend on the nature of the structures and their operating conditions. There are three types of building masonry mortars: Cement, cement-lime and lime.

Cement mortars are used for underground masonry and masonry below the waterproofing layer, when the soil is saturated with water, i.e., in cases where it is necessary to obtain a solution high strength and water resistance.

Cement-lime mortars are a mixture of cement, lime paste, sand and water. These solutions have good workability, high strength and frost resistance. Cement-lime mortars are used for the construction of underground and above-ground parts of buildings.

Lime mortars have high plasticity and workability, adhere well to the surface, and have low shrinkage. They have a fairly high durability, but are slow hardening. Lime mortars are used for structures operating in the above-ground parts of buildings that experience little stress.

Finishing solutions.

There are finishing solutions - ordinary and decorative.

Finishing solutions are prepared on cements, cement-lime, lime, lime-gypsum binders. Depending on the field of application, finishing solutions are divided into solutions for outdoor and internal plasters. The compositions of finishing solutions are set taking into account their purpose and operating conditions. These mortars must have the necessary degree of mobility, have good adhesion to the base and change little in volume during hardening, so as not to cause cracks in the plaster.

Cement-lime mortars are used for external plasters of stone and monolithic concrete walls of buildings with a relative humidity of up to 60%, and lime-gypsum mortars are used for wooden and gypsum surfaces in areas with a steadily dry climate. For external plastering of plinths, corbels, cornices and other sections of walls subjected to systematic moisture, cement and cement-lime mortars on Portland cements are used. Lime, gypsum, lime-gypsum and cement-lime mortars are used for internal plastering of walls and ceilings of a building with a relative humidity of up to 60%.

Decorative colored solutions are used for factory finishing of the front surfaces of wall panels and large blocks, for finishing the facades of buildings and urban amenities, as well as for plastering inside public buildings.

For the preparation of decorative mortars, the following are used as binders: Portland cements (regular, white and colored) - for finishing layered reinforced concrete panels and concrete panels on light porous aggregates; lime or Portland cement (ordinary, white and colored) - for the front finishing of silicate concrete panels and for colored plasters of building facades; lime and gypsum - for colored pieces of gurok inside buildings.

As fillers for colored decorative solutions, washed quartz sand and sand obtained by crushing granite, marble, dolomite, tuff, limestone and other white or colored rocks. To give the finishing layer a shine, up to 1% mica or up to 10% crushed glass is added to the solution. Alkali-resistant and light-resistant natural and artificial pigments are used as dyes (ocher, iron red lead, mummy, chromium oxide, ultramarine, etc.).

Special solutions.

Special solutions include grouts for filling joints between elements of prefabricated reinforced concrete structures, injection grouts, floor grouts, waterproofing grouting, acoustic and X-ray protection.

Mortars for filling joints between prefabricated elements reinforced concrete structures prepared on Portland cement and quartz sand with a mobility of 7-8 cm.

Injection mortars are cement-sand mortars or cement paste used to fill the channels of prestressed structures.

Waterproofing solutions are prepared on high-grade cements (400 and higher) and quartz sand or artificially obtained sand from dense rocks.

Cement slurries are used for plugging oil wells. They must have high uniformity, water resistance, mobility; setting time corresponding to the conditions for injecting the solution into the well; sufficient water loss under pressure, resistance in an aggressive environment.

Acoustic mortars are used as sound-absorbing plaster to reduce noise levels.

X-ray protective solutions are used for plastering walls and ceilings x-ray rooms.

Depending on the type of structure (wall, foundation, etc.) and the conditions in which it will work, based on the requirements of SNiP, the basic requirements for solutions (grade, water resistance, frost resistance) for the construction or installation of this structure are established.

Masonry mortars are used depending on the design stresses and operating conditions of the masonry. It is recommended to carry out the laying of elevated structures operating at low voltage using mortars containing cheap local binders: lime-slag, lime-pozzolanic, lime. In mortars for laying foundations with aggressive sulfate waters, sulfate-resistant cements are used, for the installation of large-block and large-panel walls - Portland cement, Portland slag cement, as well as Portland cement with organic additives. The mobility of the mortar mixture is chosen taking into account the purpose of the solution. When laying walls from hollow brick or ceramic stones mobility is assigned 7 ... 8 cm, with rubble masonry -4 ... 6 cm, for masonry from solid brick and concrete stones- 8 ... 12 cm, for mounting walls from panels and large blocks -5 ... .7 cm, for filling voids in the masonry and supplying with a mortar pump -12 ... 14 cm.

Mounting solutions. When installing walls, horizontal seams between panels of heavy concrete are filled with a solution of grade not lower than Ml00; from lightweight concrete- not lower than M50. When installing walls from large blocks, the brand of mortar for filling horizontal joints is indicated in the project (usually M10 ... M50). For jointing vertical joints of panel and large-block walls, the brand of mortar must be at least M50.

For the installation of load-bearing reinforced concrete structures, the brand of cement mortar must not be lower than the brand of concrete of this structure.

As a filler for heavy masonry and installation mortars, quartz sand is used according to GOST 8736-93, which should not contain particles larger than 5 mm, and the fineness modulus should be 1.5 ... 2.5.

When laying mortars in winter, the hardening rate slows down. For example, at the age of 28 days. the strength of solutions hardening at a temperature of 1 °C is half that at a hardening temperature of 20 °C. Therefore, in winter, for masonry and sealing joints in prefabricated elements, a mortar with a grade one or two steps higher than for a mortar used for the same purposes in summer is used. Solutions for winter work may be served warm. The temperature of the solution at the time of its application should be at least 10 °C at an outside air temperature of minus 10 ... 15 °C and not less than 20 °C - at an air temperature below minus 20 °C.

The temperature of mixtures for the installation of structures should be 10 ° C higher than for masonry.

In construction, monolithic plaster obtained from plaster solutions. The plaster coating consists of two or more layers. Adhesion to the base surface is provided by a preparatory layer, or spray, not more than 5 mm thick on brick and concrete surfaces and 9 mm - for wood. The main layer (soil) with a thickness of 5 ... 7 mm is used to obtain flat surface. An improved appearance is achieved due to the covering layer with a thickness of no more than 2 mm.

As a filler for plaster mortars, natural sand of the "very fine", "fine" and "medium" groups is used (size modulus - up to 2.0).

Maximum allowable size grains of sand for the preparatory layers of spray and soil should not exceed 2.5 mm, for the finishing layer (covering) - 1.2 mm.

Properties of different layers plaster system must be coordinated with each other in such a way that no stresses arise on the interfaces between the layers and the base due to shrinkage and thermal expansion. For this, it is necessary that the strength of the upper layer be less than the strength of the lower one, or that both layers have the same strength.

Solutions for conventional plasters subdivided into cement, lime, gypsum, cement-lime, lime-gypsum, gypsum and clay-lime. The binder for solutions of conventional plasters is chosen depending on the humidity conditions of operation.

Cement mortars are used for external plasters subjected to systematic moistening (external walls, cornices, etc.), and internal - in rooms with relative humidity air over 60%. To increase their water resistance, it is desirable to use water-repellent additives, such as organosilicon fluids.

Cement-lime mortars are used for plastering both building facades (structures that are not subjected to systematic moisture) and interior spaces. The introduction of lime sharply increases the plasticity of solutions. The content of the lime paste depends on the purpose of the layer.

Solutions based on airborne lime and gypsum are used for plastering indoor surfaces with relative humidity up to 60%. The main disadvantage of lime mortars is slow hardening. To speed up their hardening, add building plaster. The most convenient lime-gypsum solutions for plastering wooden surfaces indoors. To increase their water resistance, hydraulic additives are introduced into the solution: tripoli, diatomite, slag, ash, etc.

All types of plaster mortars must have a given mobility (9 ... 14 cm - for spraying with mechanized application, 7 ... .8 cm - for soil and covering); not delaminate during the production process; provide the specified strength and adhesion to the base.

Protective and decorative solutions and compositions are intended for outdoor and interior decoration various porous surfaces, performing plastering and filling works. Depending on the type, dry and mortar mixtures, as well as paste compositions, and depending on the composition of the incoming components - mineral, polymer-mineral and polymer compositions.

Protective and finishing plasters must meet a number of specific requirements related to their purpose and operating conditions. The most important are the strength of adhesion to the base and frost resistance. The main indicators of the quality of protective and finishing plasters according to STB 1263-2001 are given in Table. 22.

The stability of these indicators over time depends mainly on the properties of the components of the solutions. Binders for decorative mortars and compositions applied to the exterior surfaces of buildings include white and colored Portland cement, Portland cement with organic additives. In addition, for protective coating often use solutions on a polymeric binder. Lime, gypsum, gypsum-polymer-cement and polymer-cement binders are more often used for interior decoration.

Coloring additives are light, alkali and acid resistant pigments of natural or artificial origin, such as chromium oxide, red lead, graphite, ultramarine, ocher. Of the white pigments, the most commonly used are lime, marble flour, white Portland cement, and titanium dioxide.

Fillers for decorative solutions are washed natural and artificial sands, ceramic, glass, plastic and crushed rocks with a particle size of 2 ... 5 mm. In necessary cases, to obtain sparkling surfaces, mica or crushed

High physical and mechanical properties, comparable with foreign analogues, are possessed by a polymeric protective and finishing acrylic plaster produced by Apimiks. Decorative plasters"Apimix-Sh" are produced on the basis of 100% copolymer of acrylic, quartz sand or marble chips and additives (antistatic, antifungal and anti-mould) and are colored with inorganic pigments. Acrylic plasters do not contain cement and have increased water resistance compared to mineral or polymer-mineral plasters, while maintaining vapor permeability within the required limits; can be applied to any prepared substrate. Plasters "Apimix-Sh" are very resistant to abrasion, resistant to impact and scratching, hardly flammable. They are recommended for finishing wall surfaces on stairwells, in lobbies, cash halls, for prestigious decoration office buildings and façade decorations.

Solutions for special purposes. Waterproofing (waterproof) solutions - conventional greasy solutions with a composition of 1: 1-1: 3.5, into which sealing agents (aluminum sulfate, calcium nitrate, iron chloride, bitumen emulsion, water-soluble resins) or water-reducing (plasticizing) additives are introduced. Solutions with the addition of water glass or sodium aluminate quickly set, which allows them to be used to seal cracks from which water oozes.

For waterproofing mortars, Portland cement, pozzolanic, sulfate-resistant and hydrophobic Portland cement, aluminous and expanding cements of at least M400 grades are used. As a fine aggregate in waterproofing solutions for screeds, sand with a fineness modulus of 2 ... 3 is used.

Especially reliable are waterproofing mortars applied by gunning, the modulus of sand size of which should be 2.5 ... 3.5. Such solutions are used to cover the walls of pools, pipelines, tunnels, basements exposed to aggressive environments.

Heat-insulating and acoustic solutions are used instead of conventional plaster solutions in order to increase heat-shielding properties enclosing structures or giving them sound-absorbing properties.

Porous sands are used as fillers for heat-insulating and acoustic solutions: perlite - grades 100, 150 and 200, expanded clay - grades 500 ... ,16 and larger than 2.5 mm - no more than 15%, agloporite and expanded clay sand - respectively less than 0.16 and larger than 5 mm - no more than 5%.

For acoustic solutions, one-fraction sands with a grain size of 3 ... 5 mm are used.

X-ray protective solutions. it heavy solutions with a density of more than 2200 kg / m3, used for plastering X-ray rooms and rooms in which work is carried out related to X-ray or y-radiation. Such plaster replaces the sheathing with lead sheets. Portland cement or Portland slag cement and special heavy aggregates (barite), iron ores (magnesite, limonite) and others in the form of sand and dust with a particle size of not more than 1.25 mm are used as binders. The following composition of the barite solution (may hours) can be recommended: ground barite concentrate - 4; fast-hardening Portland cement - 1; polyvinyl acetate dispersion - 0.1; water - to the required mobility.

acid resistant solutions. These are solutions on an acid-resistant liquid glass binder used for the device anti-corrosion coatings structures that are exposed to acids during operation.

Liquid glass is used as a binder in these solutions: sodium glass with a silicate module of 2.4 ... 2.8 and a density of 1.38 ... 1.40 g / cm3 and potassium glass with a silicate module of 3 ... 3.2 and with a density of 1.30 ... 1.32 g / cm3 (paragraph 9.6). The filler is natural quartz or artificial sand obtained by crushing acid-resistant rocks (andesite, beshtaunit, granite). The sand should not contain clay impurities, grains of carbonate rocks and impurities of organic substances.

In acid-resistant solutions, in addition to sand, a finely ground filler is introduced - powder from acid-resistant rocks (andesite, diabase). The filler must contain at least 70% of grains up to 0.075 mm in size.

To increase water resistance, special finely ground additives are used containing reactive silica - silica gel, diatomite, tripoli, agloporite, acid ash from thermal power plants. The acid resistance of fillers should be at least 96%, while the active silica (capable of interacting with alkali) should be 84 ... 97%. The consumption of the active additive is approximately 5...22% by weight of the finely ground filler.

To improve the water resistance of acid-resistant, polymeric additives are used, for example, furyl alcohol.

1. Simple:

1. when sand is mixed with lime milk, lime mortar is obtained (the ratio of lime and aggregate can be different: 1:1; 1: 1.5; 1: 2; 1: 2.5; 1: 3; 1: 3.5; 1: 4 ), which is characterized by workability and good adhesion to the masonry material. As a rule, such solutions have low grades and are used for plastering. internal surfaces and when laying the walls of low-rise buildings;
2. astringent in gypsum solutions is building plaster. Such solutions are used for laying walls and piers erected from gypsum stones and plates;
3. cement mortars are used when laying the foundation, walls with a thickness of not more than 250 mm and walls made by the method of lightweight masonry. In addition, they are used for laying walls in winter by freezing, as well as in rooms with high humidity. In private housing construction, cement mortars are not recommended for wall masonry. The exception is masonry cladding, which is more exposed to natural and climatic factors, and the walls themselves are built on complex or lime mortars.

2. Complex:

1. to increase strength lime mortar, cement is introduced into it. Their main purpose is laying internal walls, wall plastering basements(for masonry carried out below the level ground water, these solutions are not used). To obtain a cement-lime mortar, such an amount of water is added to the lime paste to obtain milk of lime, which closes the mixture of sand and cement (they are combined in a dry form and thoroughly mixed). Depending on the degree of humidity of the building under construction, the proportions of cement, lime paste and sand change.
   As a result, the solution becomes more plastic and “warm” (they can be plastered with walls to increase their heat-insulating properties, hence the name “warm plasters”);
2. stronger than cement-lime mortars are cement-clay (the ratio of cement and clay is 1: 1). In addition, they are distinguished by a quick setting, they are less prone to delamination during transportation. These solutions are suitable for use in winter time, since clay, having the ability to retain water, increases the strength characteristics of the solution when thawed.

In order to inform
So, building mixture is a mixture of sand, binder and water. Their main part is sand, the particle size of which is no more than 4 mm. The components of the solution in the preparation of the mixture are measured by volume parts. In order not to violate the proportions, the measures of volume must be the same. For example, there is more wet sand in a bucket than dry sand. Only pure fresh water should be used for the solution.
In case it is required a large number of solution, it is more profitable to prepare it yourself, using a concrete mixer for this. If the amount of work is small, then it is cheaper and more convenient to purchase a dry mortar. At the same time, it is not required to buy, measure, mix individual components - just pour as much water into the mixture as indicated in the instructions, and use a special mixer (or a drill with a nozzle) to bring it to a homogeneous state. Construction mixtures are compiled by highly professional specialists, therefore, a solution prepared from such a composition will be of the appropriate quality.