Drainage concrete composition. Bearing layers of drainage concrete. Concrete rain tray - design and application specifics of concrete trays
Cement concretes are prepared on various cements. I'll give you the most common ones.
The main one is Portland cement and its varieties. Widely applied slag Portland cements and pozzolanic cements.
Sand concrete (cement mortar)- a mixture of cement and sand and water of medium or coarse fraction.
silicate concretes prepared on the basis of lime. Lime can be used in combination with hydraulic active and (or) silica components (cement, slag, quartz sand and active mineral additives).
Gypsum concretes- concretes based on semi-aqueous gypsum or anhydride (including gypsum-cement-pozzolanic, etc. binders). They are used for internal partitions, suspended ceilings, elements of building decoration and low-rise construction.
Slag concrete- concretes based on ground ash slags with hardening activators (alkaline solutions, lime, cement or gypsum).
Polymer concretes are made on various types of polymeric binder, which is based on resins (polyester, epoxy, carbamide, etc.) or monomers, such as furfural acetone, cured in concrete with the help of special additives. These concretes are more suitable for service in aggressive environments and special conditions of exposure (abrasion, cavitation, etc.).
Below is a general classification of concrete based on GOST 25192-2012 - "Concrete. Classification and general technical requirements."
Concrete classification
Main purpose
class="h3_font">- Structural- for concrete and reinforced concrete load-bearing structures of buildings and structures (foundation blocks, columns, beams, slabs, etc.).
- Prestressing concrete: concrete containing an expanding cement or an expanding admixture that causes the concrete to expand as it cures.
- Fast setting concrete: concrete having a fast rate of curing.
- High performance concrete: Concrete that meets special functional requirements that cannot be achieved using traditional ingredients, mixing, laying, maintenance and curing methods.
- decorative concrete: concrete obtained by painting, polishing, texturing, embossing, engraving, topping and other processes to achieve the desired aesthetic properties.
- Draining concrete: concrete containing coarse aggregates with no or minimal content of fine aggregates, as well as an insufficient amount of cement paste to fill pores and voids.
- Special- chemically resistant, heat-resistant, decorative, extra heavy, for biological protection, concrete polymers, polymer concretes, etc.
- hydrotechnical - for the construction of dams, locks, lining of canals, etc.;
- heat-insulating (for example, perlite concrete);
- concrete for building walls and light ceilings;
- road - for the device of road and airfield coverings;
Corrosion resistance
class="h3_font">- A - concretes operated in an environment without the risk of corrosion (CW);
- B - concretes operated in an environment that causes corrosion under the action of carbonization (CS);
- B - concretes operated in an environment that causes corrosion under the action of chlorides (XD and XS);
- D - concretes operated in an environment that causes corrosion under the action of alternate freezing and thawing (XF);
- D - concretes operated in an environment causing chemical corrosion (CA).
Note - The operating environment of concrete is specified in accordance with GOST 31384.
Heat resistant concrete: concrete designed to work in conditions of exposure to temperatures from 800 ° C to 1800 ° C.
acid resistant concrete: concrete for work in aggressive acidic environments.
By type of binder
class="h3_font">- cement (prepared on clinker cements - Portland cement, Portland slag cement, Portland pozzolanic cement, etc.);
- silicate autoclave hardening (on lime-sand, lime-slag and other binders);
- calcareous;
- slag;
- gypsum (on gypsum and pozzolanic binders);
- bituminous (asphalt concrete);
- synthetic resins (polymer concrete and polymer concrete);
- magnesia binders;
- special (acid-resistant concretes on liquid glass).
Concrete aggregates
class="h3_font">- dense;
- porous;
- special (for example, metal shot, expanded polystyrene granular);
I would greatly expand this classification. For example, added "reinforcing (fibre)"; "fraction size"; "mineral and organic fillers". There is such an extensive practice of using various fillers that it does not even make sense to classify them here, I will simply list some of the concretes:
Agloporite concrete: concrete on agloporite crushed stone or gravel;
Arbolit: concrete in which organic materials of plant origin are used as aggregate.
Armocement: fine-grained concrete, in the mass of which woven or welded wire meshes of metal or non-metal are evenly distributed. Note - Reinforced cement can be additionally reinforced with bar or wire reinforcement.
Concrete polymer: concrete impregnated with monomers or liquid oligomers with their subsequent polymerization (hardening) in the pores of concrete.
Vermiculite concrete: concrete on expanded vermiculite;
soil concrete: concrete obtained from a mixture of ground or granulated soil, a binder and a mixing agent.
ash concrete: lightweight concrete, the aggregate in which is ash.
Expanded clay concrete: concrete on expanded clay gravel;
Fine-grained concrete: concrete on cement binder with dense fine aggregate.
Perlite concrete: concrete on expanded perlite crushed stone;
Polymer concrete: concrete made from a concrete mix containing a polymer or monomer.
Reaction Powder Concrete: concrete made from finely ground reactive materials with a grain size of 0.2 to 300 microns and characterized by high strength (more than 120 MPa) and high water resistance.
Recycled concrete: concrete made using recycled binders, aggregates and water.
silicate concrete: concrete in which lime is used as a binder.
Thermolithic concrete: concrete on thermolite crushed stone or gravel;
heavy concrete: concrete on cement binder with dense fine and coarse aggregates.
Fiber concrete: concrete containing dispersed, randomly oriented fibers.
slag concrete: concrete on ash and slag mixtures of thermal power plants - thermal power plants or on fuel slag, granulated blast furnace or electrothermophosphorus slag.
Slag-pumice concrete: concrete on slag-pumice rubble or gravel;
Shungizite concrete: concrete on shungizite gravel;
Content of binder and aggregates
class="h3_font">- Skinny(with a low content of a binder and a high content of coarse aggregate);
- Fatty(with a high content of a binder and a low content of coarse aggregate);
- Commodity(with the ratio of fillers and binder according to the standard recipe).
Structure of concrete
class="h3_font">- dense;
- porous;
- cellular;
- macroporous.
dense concrete: concrete, in which the space between the grains of coarse and fine aggregates or only fine aggregates is filled with a hardened binder and entrained air pores, including those formed through the use of additives that regulate the porosity of the concrete mix and concrete.
Porous concrete: concrete, in which the space between the grains of coarse aggregate is filled with a hardened porous binder.
Cellular concrete (aerated concrete and foam concrete): Concrete consisting of a hardened mixture of a binder, a silica component and artificial evenly distributed pores in the form of cells formed by gas and foam concentrates.
Coarse-pored concrete: Concrete in which the space between coarse aggregate grains is not completely filled with fine aggregate and hardened binder.
Hardening conditions
class="h3_font">- in natural conditions;
- under conditions of heat treatment at atmospheric pressure;
- under conditions of heat treatment at a pressure above atmospheric (autoclaved concrete).
- in wet/dry conditions
Formation method
class="h3_font">- Cast concrete (pouring): concrete obtained from a concrete mix with a slump greater than 20 cm.
- self-sealing- concrete made from a concrete mixture capable of compacting under its own weight.
- Roller Formation- rigid concrete, compacted by roller molding.
- Rolled concrete: especially hard concrete, compacted by vibro-rolling or tamping.
- shotcrete: fine-grained concrete pneumatically applied to the surface.
- Underwater concrete: concrete laid under water by pipelines or other means.
- Vacuum concrete: concrete from which, before it hardens, part of the water and entrained air is removed by vacuum.
Workability
class="h3_font">- super hard(rigidity over 50 seconds) for foundations, beams and other critical structures,
- hard(hardness from 5 to 50 seconds) for forms of complex configurations,
- mobile(hardness less than 4 seconds, subdivided according to the draft of the cone) for less critical products: screeds, paths, blind areas, etc.
This is not the case in SNIP.
Concrete strength
class="h3_font">- medium strength (compressive strength class B<=В50);
- high-strength (compressive strength class B>=B55).
I would divide it into: Thermal insulation (B0.35 - B2); Structural and heat-insulating (B2.5 - B10); Structural concrete (B12.5 - B40); Concrete for reinforced structures (from B45 and above).
Curing rate under normal conditions
class="h3_font">- fast hardening;
- slow hardening.
The ratio given in the table is taken as the criterion for assessing the rate of curing.
R 2 - strength of concrete at the age of 2 days;
R 28 - strength of concrete at the age of 28 days.
Density of concrete
class="h3_font">Medium density grade D corresponds to the average value of the volumetric mass of concrete in kg/m3. The range of the indicator is from D200 to D5000.
- extra light- grades with an average density of less than 500 kg / m 3 are used as a heat-insulating material;
- lungs- grades by average density from 500 to 1800 kg / m 3 (expanded concrete, foam concrete, aerated concrete, wood concrete, vermiculite, perlite), used for the manufacture of monolithic enclosing structures (walls) and block wall materials;
- lightweight density from 1800 to 2200 kg / m 3, used in load-bearing structures in the construction of buildings no higher than two floors (cottage construction);
- heavy- density from 2200 to 2500 kg/m 3 (gravel, basalt, limestone, granite), this type of concrete is used in all load-bearing structures;
- especially heavy- with a density of 2500 kg / m³ (barite, magnetite, limonite), such concrete is used in special structures to protect against radiation.
Frost resistance of concrete
class="h3_font">Concrete grade for frost resistance F corresponds to the minimum number of cycles of alternate freezing and thawing, maintained by the sample during the standard test. The indicator range is from F15 to F1000.
For self-tensioning concretes, a self-stressing grade is established.
- low frost resistance (frost resistance grades F50 or less);
- medium frost resistance (frost resistance grades over F50 to F300);
- high frost resistance (frost resistance grades over F300).
Water resistance of concrete
class="h3_font">Concrete grade for water resistance W corresponds to the maximum value of water pressure (MPa.10 -1) maintained by a concrete sample during testing. The range of the indicator is from W2 to W20.
- low water resistance (water resistance grades less than W4);
- medium water resistance (water resistance grades from W4 to W12);
- high water resistance (water resistance grades over W12).
Abrasion of concrete
class="h3_font">- low abrasion (abrasion grade G1);
- medium abrasion (abrasion grade G2);
- high abrasion (abrasion grade G3).
Marking of cements
To determine the brand of concrete, you need to know the characteristics of cement, which manufacturers must indicate in the marking.
An example of a symbol for Portland cement grade 400, with additives up to 20%, fast-hardening, plasticized: PC 400 - D20 - B - PL - GOST 10178.
Trays are widely used in linear (surface) drainage systems. They are the main element of the drainage system and are combined into channels. Trays are made of various materials, one of the most relevant is concrete.
Tray storm concrete - production
High-quality concrete trays are created from B30 heavy concrete mix. The production process is carried out by the vibrocompression method, due to which the products have high technical characteristics.
Such concrete channels for drainage have high wear resistance and water resistance. Thanks to these qualities, the drainage channels are reliably protected from the aggressive effects of water flows and suspended particles.
In addition, concrete storm trays are reinforced with steel rod reinforcement. High-quality reinforcement can significantly increase their strength. The whole structure serves for a long time due to the treatment of reinforcement with an anti-corrosion compound.
To protect the trays from the inside, gratings are attached to them from above. Reliable concrete trays with grating are not clogged with large debris that is present in storm drains.
Concrete rain tray - design and application specifics of concrete trays
The main task of drainage is to exclude the bay and swamping of the territory, and drainage drainage significantly extends the service life of structures and structures on it. High-quality concrete channels for drainage contribute to this, they are universal, as they can be used in almost all drainage systems. They also do not require repair for several years at low loads.
Concrete drain channels are also effective for protecting roads from the effects of precipitation. They prevent blurring and destruction of the edges of asphalt pavements. Standard concrete drain trays have a rectangular shape, protected from above by a cast-iron grate.
Applicable concrete catchment trays at service stations, gas stations, industrial and production areas. They are also widely used at train stations and airports.
Concrete gutter tray - application advantages
The use of concrete channels has its advantages. High-quality concrete drainage channel allows you to:
- provide drainage at the maximum level of surface water;
- drainage to withstand high static and dynamic loads;
- increase the service life of structures and structures, avoid the need for repairs for a long time.
A high-quality concrete drainage tray with a grate has high frost resistance, provides quick maintenance and repair of drainage systems.
GOST 25192-2012
INTERSTATE STANDARD
CONCRETE
Classification and general technical requirements
Concretes. Classification and general technical requirements
_________________________________________________________________
For the text of Comparison of GOST 25192-2012 with GOST 25192-82, see the link.
- Database manufacturer's note.
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ISS 91.100.30
Introduction date 2013-07-01
Foreword
The goals, basic principles and basic procedure for carrying out work on interstate standardization are established by GOST 1.0-92 "Interstate standardization system. Basic provisions" and GOST 1.2-2009 "Interstate standardization system. Interstate standards, rules and recommendations for interstate standardization. Rules for the development, adoption, application, renewal and cancellation
About the standard
1 DEVELOPED by the Russian Academy of Engineering
2 INTRODUCED by the Technical Committee for Standardization TC 465 "Construction"
3 ADOPTED by the Interstate Scientific and Technical Commission for Standardization, Technical Regulation and Conformity Assessment in Construction (Appendix B to Protocol No. 40 dated June 4, 2012)
Voted for the adoption of the standard:
Short name of the country according to MK (ISO 3166) 004-97 | Abbreviated name of the national body of state management of construction |
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Azerbaijan | State Committee for Urban Planning and Architecture |
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Ministry of Urban Development |
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Kazakhstan | Agency for Construction and Housing and Communal Services |
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Kyrgyzstan | Gosstroy |
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Ministry of Construction and Regional Development |
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the Russian Federation | Ministry of Regional Development |
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Tajikistan | Agency for Construction and Architecture under the Government |
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Uzbekistan | Gosarchitektstroy |
4 By order of the Federal Agency for Technical Regulation and Metrology dated December 27, 2012 N 2003-st, the interstate standard GOST 25192-2012 was put into effect as the national standard of the Russian Federation from July 1, 2013.
5 INSTEAD OF GOST 25192-82
Information about changes to this standard is published in the annual information index "National Standards", and the text of changes and amendments - in the monthly information index "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly information index "National Standards". Relevant information, notification and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet
1 area of use
1 area of use
This standard applies to concrete used in all types of construction.
The standard does not apply to concretes with bituminous binders.
The standard establishes the classification of concrete and general technical requirements for them.
The requirements of this standard must be observed when developing new and revising existing regulatory and technical documents, design and technological documentation for concrete mixtures, prefabricated and monolithic, concrete and reinforced concrete structures and products.
2 Classification of concrete
2.1 Concrete is classified according to the following criteria:
- main purpose;
- resistance to types of corrosion;
- type of binder;
- type of fillers;
- structure;
- hardening conditions;
- strength;
- the rate of strength gain;
- average density;
- frost resistance;
- water tightness;
- abrasion.
2.2 Depending on the main purpose, concrete is divided into:
- structural;
- special (for example, heat-insulating, radiation-resistant, decorative).
2.3 By resistance to types of corrosion, concretes are divided into the following types:
A - concretes operated in an environment without the risk of corrosion (CW);
B - concretes operated in an environment that causes corrosion under the action of carbonization (CS);
B - concretes operated in an environment that causes corrosion under the action of chlorides (XD and XS);
D - concretes operated in an environment that causes corrosion under the action of alternate freezing and thawing (XF);
D - concretes operated in an environment causing chemical corrosion (CA).
Note - The operating environment for concrete is specified in accordance with GOST 31384.
2.4 According to the type of binder, concretes are divided into:
- cement;
- lime;
- slag;
- plaster;
- special (for example, polymer concrete, concrete on magnesia binder).
2.5 According to the type of aggregates, concretes are divided into concretes on aggregates:
- dense;
- porous;
- special (eg metal shot, expanded polystyrene granules).
2.6 According to the structure, concretes are divided into concretes with the structure:
- dense;
- porous;
- cellular;
- coarse.
2.7 According to the conditions of hardening, concretes are divided into hardening:
- in natural conditions;
- under conditions of heat treatment at atmospheric pressure;
- under conditions of heat treatment at a pressure above atmospheric (autoclaved concrete).
2.8 By strength, concrete is divided into concrete:
- medium strength (compressive strength class BB50);
- high-strength (compressive strength class BB55).
2.9 According to the rate of curing under normal hardening conditions, concretes are divided into:
- fast hardening;
- slow hardening.
The ratio given in Table 1 is taken as the criterion for assessing the rate of curing.
Table 1
Type of concrete | |
Fast hardening | More than 0.4 |
slow curing | |
* - strength of concrete at the age of 2 days; Strength of concrete at the age of 28 days. |
|
2.10 According to the average density, concretes are divided into:
- extra light (grades of average density less than D800);
- light (grades by average density from D800 to D2000);
- heavy (grades by average density more than D2000 to D2500);
- especially heavy (grades on average density more than D2500).
2.11 According to frost resistance, concretes are divided into concretes:
- low frost resistance (frost resistance grades F50 or less);
- medium frost resistance (frost resistance grades over F50 to F300);
- high frost resistance (frost resistance grades over F300).
2.12 According to water resistance, concretes are divided into concretes:
- low water resistance (water resistance grades less than W4);
- medium water resistance (water resistance grades from W4 to W12);
- high water resistance (water resistance grades over W12).
2.13 By abrasion, concretes are divided into concretes:
- low abrasion (abrasion grade G1);
- medium abrasion (abrasion grade G2);
- high abrasion (abrasion grade G3).
3 Name of concrete
3.1 The name of concrete of a certain type (kind) should include, as a rule, all the classification features established by this standard (see Appendix A). Features that are not decisive for concrete of a given type (type) may not be included in its name. In the designation of structural concrete, the word "structural" may be omitted.
If necessary, the name of concrete may indicate specific types of binders, aggregates, hardening conditions, as well as the type (type) of concrete, specifying its purpose, properties, composition or manufacturing technology.
3.2 For concretes characterized by the most commonly used combinations of features, the following names are used: "heavy concrete", "fine-grained concrete", "lightweight concrete", "cellular concrete", "silicate concrete", "heat-resistant concrete", "chemically resistant concrete" .
4 General technical requirements
4.1 Requirements for the quality of concrete should be established in accordance with the requirements of this standard, depending on their purpose and working conditions in the structures of buildings and structures:
- in standards for concrete of a certain type (kind);
- in standards and specifications for prefabricated concrete and reinforced concrete products;
- in the working drawings of monolithic concrete and reinforced concrete structures.
4.2 Normative or technical documents for concrete of specific types (types) should contain parametric series of values of standardized concrete quality indicators controlled during the production of structures (strength classes; grades for frost resistance, water resistance, average density, and others).
4.3 Each standardized quality indicator must have a standardized methodology for its determination, and in its absence, a methodology approved in the prescribed manner, which should be given in a regulatory or technical document establishing the requirement for this quality indicator.
4.4 Requirements for materials for the preparation of concrete mixtures (binders, additives, aggregates, aggregators) and for the composition of concrete should be established in regulatory or technical documents, as well as in technological documentation for concrete of a particular type.
4.5 Requirements for standardized technological parameters of concrete mixes and production technology for the manufacture of concrete and reinforced concrete structures should be contained in the technological documentation (project for the production of works, technological regulations or technological map) for the manufacture of structures of specific types at specific enterprises.
4.6 The values of standardized concrete quality indicators should be determined by testing specially made control samples or testing concrete in structures according to standardized methods.
4.7 The values of standardized concrete quality indicators may be determined by several methods, while comparability of the results should be ensured by establishing transition factors or other methods.
4.8 Compliance of the quality indicators of concrete with the design requirements is established by evaluating the test results, taking into account the homogeneity indicators of the controlled quality indicator.
Annex A (informative). Examples of clarifying names of types (kinds) of concrete
Annex A
(reference)
A.1 Clarification of the names of types (kinds) of concrete according to their properties
A.1.1 tension concrete: Concrete containing an expanding cement or an expanding admixture that causes the concrete to expand as it cures.
A.1.2 fast setting concrete: Concrete with a fast curing rate.
A.1.3 high performance concrete: Concrete that meets special functional requirements that cannot be achieved using traditional ingredients, mixing, laying, curing and curing methods.
A.1.4 decorative concrete: Concrete obtained by painting, polishing, texturing, embossing, engraving, topping and other processes to achieve the desired aesthetic properties.
A.1.5 drainage concrete: Concrete containing coarse aggregates with no or minimal content of fine aggregates, as well as an insufficient amount of cement paste to fill pores and voids.
A.1.6 refractory concrete: Concrete designed to work under conditions of exposure to temperatures from 800 ° C to 1800 ° C.
A.2 Clarification of the names of types (kinds) of concrete by composition
A.2.1 wood concrete: Concrete in which organic materials of plant origin are used as aggregate.
A.2.2 armocement: Fine-grained concrete, in the mass of which woven or welded metal or non-metallic wire meshes are evenly distributed.
Note - Reinforced cement can be additionally reinforced with bar or wire reinforcement.
A.2.3 concrete polymer: Concrete impregnated with monomers or liquid oligomers, followed by their polymerization (curing) in the pores of concrete.
A.2.4 ground concrete: Concrete obtained from a mixture of ground or granulated soil, binder and aggregator.
A.2.5 ash concrete: Lightweight concrete, the aggregate in which is ash.
A.2.6 extra heavy concrete: Dry medium density concrete over 2500 kg/m3, which contains special aggregates.
A.2.7 heavy concrete: Concrete on cement binder with dense fine and coarse aggregates.
A.2.8 fine-grained concrete: Concrete on cement binder with dense fine aggregate.
A.2.9 polymer concrete: Concrete made from a concrete mix containing a polymer or monomer.
A.2.10 reaction powder concrete: Concrete made from finely divided reactive materials with a grain size of 0.2 to 300 µm and is characterized by high strength (more than 120 MPa) and high water resistance.
A.2.11 silicate concrete: Concrete in which lime is used as a binder.
A.2.12 recycled concrete: Concrete made using recycled binders, aggregates and water.
A.2.13 fiber concrete: Concrete containing dispersed, randomly oriented fibers.
A.3 Clarification of the names of types (kinds) of concrete according to manufacturing technology
A.3.1 autoclaved concrete: Prefabricated concrete that hardens at above atmospheric pressure.
A.3.2 underwater concrete: Concrete placed under water by pipelines or other means.
A.3.3 roller molded concrete: Rigid concrete compacted by roller molding.
A.3.4 vacuum concrete: Concrete from which some of the water and entrained air has been removed by vacuum before it hardens.
A.3.5 extra hard concrete Concrete obtained from a concrete mix with unmeasured slump and stiffness.
A.3.6 cast concrete: Concrete obtained from a concrete mixture with a draft of more than 20 cm.
A.3.7 self-compacting concrete: Concrete made from a concrete mix capable of being compacted by its own weight.
A.3.8 shotcrete: Fine-grained concrete pneumatically applied to the surface.
A.3.9 rolled concrete: Particularly rigid concrete, compacted by vibro-rolling or trombling.
A.4 Clarification of the names of types (kinds) of concrete by structure
A.4.1 dense concrete: Concrete, in which the space between the grains of coarse and fine aggregates or only fine aggregates is filled with a hardened binder and entrained air pores, including those formed due to the use of additives that regulate the porosity of the concrete mix and concrete.
A.4.2 porous concrete: Concrete, in which the space between the grains of coarse aggregate is filled with a hardened porous binder.
A.4.3 cellular concrete (aerated concrete and foam concrete): Concrete, consisting of a hardened mixture of a binder, a silica component and artificial evenly distributed pores in the form of cells formed by gas and foam formers.
A.4.4 coarse concrete: Concrete in which the space between coarse aggregate grains is not completely filled with fine aggregate and hardened binder.
Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2013
Drainage concrete (DBT) bearing layers are used to improve drainage. If water is not drained under the road surface, a so-called “pumping effect” can occur on the bearing layer and road surface as a result of high traffic, leading to damage and defects. Washing out of the base layer material leads to the formation of voids, leading to breaks in the concrete pavement. To a greater extent, low-lying roads (low drainage points) are prone to this, where water is drained from large areas. Carrier layers of drainage concrete can be used over the entire surface or on certain dangerous sections of the road and dramatically improve the drainage situation.
Bearing layers of drainage concrete are installed under the tile flooring or paving stones. With a water-permeable surface reinforcement, the bearing layers of drainage concrete meet the requirements for high stability and sufficient infiltration of rainwater.
1. General information
Drainage concrete is a concrete with a large-pore loose structure containing the required amount of mortar with fine-grained sand, which contributes to the enveloping of the granular aggregate and the point adhesion of its components (Fig. 3). Between the grains of the aggregate, voids are formed that are not filled with a solution with fine-grained sand. In the bearing layer of drainage concrete, the content of these voids is from 15% of the volume.
The applications of drainage concrete are varied, ranging from filter pipes, drainage stones and drainage concrete bearing layers to modified drainage concrete pavements, which not only contribute to good drainage, but also to reduce traffic noise due to the high sound absorption of the large-pore loose structure. This specification covers only load-bearing layers of drained concrete laid under pavement or under tile decking and pavers.
2. Basic principles of construction
The principles for the construction of load-bearing layers of drainage concrete are presented in the specification of the Research Institute of Communications "Bear-bearing layers of drainage concrete". Features of the use of drainage concrete under permeable tile flooring and pavers are described in the specification "Permeable pavement reinforcements".
Base. The basis for load-bearing layers of drainage concrete are both unbound permeable layers, such as frost protection layers, and bound dense layers, such as reinforcements, in which water can drain from the surface and be removed through a lateral drainage.
Design. Bearing layers of drainage concrete can be laid both over all surfaces and in separate areas at the lowest points of drainage. When laying in separate sections under roadsides at the lowest points of the slope, the thickness of the bearing layer with drainage concrete corresponds to the thickness of the adjacent bearing layer. In case of continuous laying of a bearing layer of drainage concrete, for example, under additional traffic lanes (Fig. 6), the thickness of the layer can be different.
It must be ensured that rainwater seeping into the drainage concrete base layer is drained through a side drain.
Beneath the concrete pavement, the inner edge of the drainage concrete carrier layer in new construction must have a protrusion of at least 20 cm in relation to the longitudinal joint of the concrete pavement located above it (for example, between the shoulder and the traffic lane) to receive seepage water. If the drainage concrete base course and/or the adjacent base course are made by mixing on site, then the drainage concrete base course should protrude 50 cm above the joint. from drainage concrete, which allows you to create uniform support conditions and a drainage zone of 20 cm.
Table 1: Requirements for the bearing layer of drainage concrete according to the norms
Requirements for the properties of the bearing layer of drainage concrete |
Tests |
Test Guide |
|
Water permeability kf ≥ 1 . 10 -3 m/s (high permeability) |
Determination of kf according to DIN 18130 |
For the bearing layer of drainage concrete, laid under paving stones, the following value kf ≥ 5.4 is sufficient. 10 -5 m/s (permeable) |
Relationship between void content H and water permeability kf |
Average tensile strength after 28 days: β 28d ≥ 8 N/mm 2 (own test |
According to TP HGT-StB |
The smallest single indicator: |
After pressing, they are sealed in synthetic film and stored for 28 days at a temperature of + 15 to + 25°C. Flattening the compression area |
When forming the outer edge of the bearing layer from drainage concrete, the requirements for bearing layers in accordance with the ZTVT-StB standards apply. According to these regulations, under the concrete pavement, it is necessary to provide a bearing layer (for example, a bearing layer of drainage concrete), the width of which will be greater than the dimensions required in accordance with the paving method used (for example, the width of the working surface of a concrete finishing machine). However, the protrusion should not be less than 35 cm. The bearing layer of drainage concrete under the paving stones:
When laying a carrier layer of drainage concrete under pavers or tile decks, the thickness of the carrier layer must comply with the requirements for carrier layers with hydraulic binders, as defined in the directives for the standardization of the surface part of public roads (RStO). As a general rule, a geotextile interlayer should be placed between the drained concrete base layer and the ballast layer of the paving stones to prevent fine components of the ballast layer from penetrating into the voids of the drained concrete base layer and to ensure sufficient seepage resistance to erosion.
3. Building materials
The drainage concrete base layer must use the same binder used in the adjacent hydraulically bonded base layer. The cement must comply with DIN EN 197. Grained aggregate or mineral substances must pass the quality control and comply with the requirements. Recycled concrete aggregates may be used if their suitability has been proven. In the specification of work, it is necessary to indicate the possibility of using secondary building materials. The maximum grain size should not exceed 32 mm. For drainage concrete load-bearing layers, different curves are used with a discontinuous particle size distribution in the 2/4 or 4/8 mm range. Large voids require low sand content. For fractions > 8 mm, crushed granular aggregate or round-grained material can be used, while it should be taken into account that crushed material (crushed stone) increases the tensile strength in bending. In order to obtain uniformly large voids, when using coarse granular aggregate, fractions > 8 mm are subject to special requirements regarding the shape of the grains. The content of grains of elongated and flat shape (the ratio of length to thickness is more than 3: 1) should not exceed 20% by weight.
The use of additives and additives that comply with the requirements of DIN 1045 or are approved by building authorities is permitted.
Any natural water can be used as the addition water, as long as it does not contain substances that prevent hardening. In case of doubt, research should be carried out. When using residual water, the provisions of the directive of the German Reinforced Concrete Committee "Concrete production using residual water, residual concrete and mortar" must be observed.
4. Building mixtures (composition, mixing)
The suitable composition of the drainage concrete base layer is determined by suitability testing. In this case, it is necessary to adhere to the requirements for the properties of the bearing layers of the drainage coating presented in Table 1. Empirical data on the composition of the mixture from the specification are given in Table 2.
When constructing a drainage concrete base layer, the water content data determined during suitability tests should be followed as closely as possible. The water-cement ratio, as a rule, should not exceed 0.40. Bearing layers of drainage concrete react even to a slight decrease in water content, which is reflected in their strength. When using residual concrete aggregate, the water and cement content increases (see table 2).
Table 2: Empirical data on the composition of the mixture according to
1) Higher values are used for recycled concrete
The high content of cement and sand contributes to a linear increase in compressive strength, but reduces the content of voids and water permeability. While the void content decreases slightly due to the increased cement content, the increase in sand content results in a significant reduction. This should be taken into account especially when mixing on site. Mortar grain fractions smaller than 2 mm are subject to special requirements with regard to limit deviations between the content obtained during suitability tests and the actual content. The suitability test data for fractions smaller than 2 mm should not be less than 3% by weight and not more than 5% by weight. For fractions > 8 mm, requirements apply. Table 3 presents selected samples of the composition of the mixture of load-bearing layers of drainage concrete, taken from the literature.
Drainage concrete base layers can be produced in a central mixing plant or mixed on site. When mixing in a mixing plant, the mixing time after adding all the components is at least 60 s.
Mixing in place requires special soil mixer equipment. One moistening of granular mixtures is not enough, since the granulometric composition of the carrier layer of drainage concrete provides water runoff. It is recommended to supply water with a spray head over the milling shaft.
5. Execution
Laying of load-bearing layers of drainage concrete is carried out, as a rule, with the help of pavers or graders. When laying the mixture, the following points must be observed:
Laying while mixing in a central mixing plant
- before laying, ensure that the finished building mixture is protected from drying out or rain
- when laying in strips, the carrier layer of drainage concrete must be laid on the not yet hardened adjacent hydraulically bonded carrier layer, first lay the dense carrier layer, and then the carrier layer of drainage concrete
- pre-compaction with the paver bar (fig. 1 and 2)
- rolling with a smooth roller without vibration (Fig. 5)
Table 3: Examples of the composition of the mixture of load-bearing layers of drainage concrete
The composition of the concrete mix |
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DBT under paving stones |
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Sand |
Sand |
Sand |
Natural sand 0/4 92 |
Large |
rubble |
Secondary |
Round grains 4/8 |
Water cement ratio |
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Density |
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Laying when mixing in place
- laying a layer across the entire width in one pass. Splicing leads to uneven density and strength
- first sand and coarse grains are fed, then cement is added, water is supplied during the milling process
- the content of granular aggregate necessary to achieve the planned layer thickness and height arrangement is determined during the preliminary tests
- pressing the finished mixture with a smooth roller
- rolling with a smooth roller without vibration
Table 4: Tests for load-bearing layers of drained concrete
Combined mixing in a central mixing plant and on site The temperature of the finished building mix during installation must be > 5 °C. At air temperatures > 25 °C, the temperature of the mortar must be checked regularly. It must not exceed +30 °C.
To protect against drying, the drainage concrete base layer must be treated immediately after installation. It is advisable to cover with a water-retaining material (for example, damp jute cloth) or synthetic film. The film must be secured against shifting when exposed to wind. Aging must be carried out for at least three days. Irrigation with water is allowed only in exceptional cases. During the first 7 days after laying, the drainage concrete bearing layer must be protected from freezing temperatures.
In rainy weather, it is advisable to use a concrete stabilizing admixture during the placement of a drainage concrete base layer when mixed in a central mixing plant, which will help prevent a thin film of mortar from being washed off the granular aggregate. The finished bearing layer of drainage concrete is checked by the construction contractor for the straightness of the profile, horizontality and layer thickness (see table 4). In this case, the requirements for carrier layers in accordance with ZTVT-StB 95 apply.
notching
In a freshly laid condition, longitudinal and transverse cuts must be made on the bearing layer of drainage concrete in those points where the longitudinal and transverse seams of the subsequently laid concrete coating will pass. Particular attention (position and depth) should be given to the creation of longitudinal cuts in the area of the inner edge of the drainage concrete bearing layer (fig. 4a and 4b).
Bearing layer of drainage concrete under paving stones
The drainage concrete base layer under paving stones and tile covering must be separated using longitudinal and transverse cuts at a distance of no more than 5 m. Protection under construction In order to avoid contamination of voids in the drainage concrete base layer, the mixture cannot be transported by on-site transport. The coatings mentioned above should be left on the base course of the drainage pavement until the concrete pavement is laid.
If during the construction process a long time elapses between the laying of the drainage cover and the concrete cover, there is a risk of erosion of the subgrade under the drainage cover, as rainwater seeps through it.
If the laying of these layers is interrupted for a long time, appropriate measures must be taken, such as strengthening the base.
6. Tests
Tests are divided into:
- suitability tests (carried out by the contractor, confirmation of the suitability of the particle size distribution of the mixture)
- own verification control (carried out by the contractor, confirmation of properties)
- control tests
(carried out by the customer, checking the properties of the bearing layer of drainage concrete and the work performed in accordance with contractual requirements).
Route drainage concrete for the installation of permeable bonded (rigid) load-bearing bases. For pedestrian loads. For laying paving stones and natural stone slabs.
Characteristics:
Specially selected fractions of aggregates allow laying a permeable bonded carrier layer with a void content of more than 20%, which reduces the risk of destruction and fading of the road surface due to freezing of standing water;
The solution is designed to create a permeable base for paving stones and slabs of natural or ceramic stone;
Mineral composition;
Suitable for the installation of water-permeable bearing layers in areas with pedestrian traffic.
Application:
For outdoor and works;
Suitable for making water-permeable bearing and sub-bases for pedestrian traffic (use category N1 ZTV Wegebau);
For laying paving stones, porcelain stoneware slabs, and natural stone.
Properties:
Dry mix of factory production;
Cement according to GOST 30515-2013
Route according to DIN 51043
Aggregates size 2-8mm according to GOST 8736-93
Contains additives to improve the properties of the solution.
Foundation preparation:
Suitable bases for the TGM are concrete or cement screeds with a slope of 1.5-3%, or a compacted gravel or crushed stone base.
When laying the slabs on waterproof substrates, it is necessary to ensure the drainage of water, for example, by means of drainage mats, gutters, etc. Water stagnation on waterproof substrates must be avoided by creating an appropriate slope. paving scheme with TGM and PFF overlays or zone (N1 according to ZTV Wegebau pedestrian zone):
Work order:
Pour 1/2 of the 40 kg bag volume into a gravity or paddle concrete mixer with a precisely measured amount of water (2.8-3.2 l). Start stirring the mixture until it reaches a liquid consistency without lumps. Then, without stopping the rotation of the drum, gradually add the rest of the contents of the bag and continue to mix until the consistency of "wet earth". Avoid the formation of lumps of the mixture during mixing.
When laying paving stones and stone using the Fresh on Fresh technique, it is necessary to use a mortar to improve adhesion.
Natural stone slabs with a strongly profiled back can be laid on a hardened, cleaned TGM drainage concrete layer after about 3 days, for example with TNM-flex natural stone routing mortar. In this case, the penetration of the solution into the seams should not be allowed.
Thickness of the TGM layer Must be at least 40mm on a concrete base, 60mm on a compacted crushed stone base and 100mm when using mortar on sand.
Diagrams of waterproof paving systems with TGM mortar
Ceramic tile or porcelain stoneware flooring with waterproof grout. On a permeable carrier base without the use of binders (
Flooring of ceramic tiles or porcelain stoneware with watertight joints on a watertight concrete slab ( zone N1 according to ZTV Wegebau pedestrian zone):
Recommendations for working with drainage concrete mortar TGM quick-mix:
The thickness of the compacted TGM sub-base will depend on the type of sub-base and expected loads, but should not be less than 40 mm when laid on a concrete base and not less than 60 mm when laid on a crushed stone base;
When using TGM drainage concrete as a bearing layer, its thickness must be at least 100mm;
Solution pot life may vary depending on ambient temperature;
Consideration should be given to slowing down the hardening of the solution at an air temperature below 15 ° C;
The fresh mortar should be protected from drying out too quickly and protected from adverse weather conditions (scorching sun, rain, strong wind, frost, etc.). If necessary, cover the mortar with a film.