Pouring a concrete slab on screw piles. Pile foundations with a monolithic slab

This page provides information about the types of slab foundations, their calculations and construction technology. You will learn what advantages and disadvantages each of them has, and in what cases it is rational to build a house on a monolithic foundation slab.

Our company is engaged in the construction of foundations from reinforced concrete piles, which are superior to slab foundations in terms of load-bearing capacity, reliability and durability. We guarantee prompt execution of foundation work in strict accordance with the requirements of construction standards, while our prices are significantly lower than the cost of similar services from competing organizations.

What is a slab foundation

A slab foundation is a continuous reinforced concrete slab underneath the entire building. It has a large supporting area and ensures reliable stability of the building. Those who decide to prefer a slab foundation for building a house benefit greatly, as they save their energy and time. Although the slab foundation is expensive to construct, it is reliable and durable and requires minimal costs for earthworks.

A slab foundation is also called a floating foundation. In this article you can learn the features of slab and pile-slab foundations, for which buildings these foundations are intended, the pros and cons of a slab foundation, and you will also learn how to correctly calculate the concrete for pouring this foundation.

Monolithic slab foundation

A monolithic slab foundation is made of highly durable concrete. For reinforcement, metal rods with a diameter of 12 to 16 millimeters are used.

This type of foundation is not afraid of seasonal temperature changes and soil movement, since the foundation moves with it, in turn, the house has a solid foundation and is thus protected from destruction.

With all its advantages, a monolithic foundation slab is one of the most expensive types of foundation, which is due to the large amount of consumables - concrete and reinforcement required for its construction.

It is rational to build a slab foundation when building houses in ground conditions, where a classic strip foundation will not have the required reliability and stability:

• In marshy, silty and peaty soils;
• In soil prone to frost heaving and with a high groundwater level;
• In moving soil that exerts horizontal loads on the foundation.

Important: the minimum thickness of the foundation slab is 30 centimeters, it can reach up to 1 m, however, the arrangement of a slab of this size requires large financial investments, which is why it is more rational to prefer a foundation on reinforced concrete piles.

Depending on the location, the foundation slab can be floating (placed on the ground surface), which is applicable only in conditions of high-density soil that is not prone to shrinkage, or buried (lowered into the ground by 3/4 of its thickness). With this approach, a layer of sand 20-30 cm thick is poured under the slab, which prevents soil shrinkage under the weight of the building and protects the foundation from the buoyant effects of heaving.

When arranging the basement floor, the foundation slab is formed at the bottom of the pit, and reinforced concrete slabs are placed along its side contours, serving as the walls of the basement and the supporting structure for the basement floor.

The process of constructing a monolithic slab foundation is carried out in the following sequence:

• The contours of the slab are marked using cast-off boards or reinforcement pegs, between which string is stretched;
• Vertical excavation of the soil is carried out - a pit for a shallow slab can be created manually; when laying a deep slab under the basement floor, special equipment is used to dig a pit;
• At the bottom of the pit, a sand cushion is formed, consisting of two layers - sand and crushed stone. The thickness of the layers should be the same (from 10 to 20 cm, depending on the density and degree of heaving of the soil). The first layer is sand, which is moistened and compacted by compaction;

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• Formwork is created from planed boards 3-4 cm thick, which is installed around the perimeter of the pit. Individual boards are knocked together into panels, which are fixed during installation using slopes and backfilling with soil;
• An oilcloth is nailed to the inner walls of the formwork, which will prevent the leakage of concrete milk through the cracks between the boards;

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• The bottom of the pit is also covered with oilcloth, after which a layer of concrete 2-3 cm thick is poured and leveled on it. After the concrete has hardened, its surface is covered with bitumen mastic, which is necessary for waterproofing when pouring the main foundation slab;

• A spatial reinforcement frame is formed on the footing, consisting of two longitudinal reinforcement contours connected to each other by vertical jumpers. The pitch of the longitudinal rods in the frame is 20 cm. There must be a distance of at least 5 cm between the side contours of the frame and the walls of the slab. To fix the reinforced frame, welding or knitting wire is used;

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• The foundation slab is poured with M200-M300 class concrete; after filling the formwork, the mixture is compacted by vibration and leveled to the same level.

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Pile-slab foundation

A pile-slab foundation is a foundation based on piles, and a monolithic reinforced concrete slab is rigidly fixed on top of the piles. This type of foundation stands out from others due to its high strength, stability and is used in the construction of multi-story buildings. The construction of such a foundation requires specialized knowledge and calculations.

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The use of piles as supports for a monolithic slab allows the construction of such a foundation in any type of soil. In this case, the slab performs the function of a grillage - a strapping that connects separate piles into a single structure and prevents them from tilting under the influence of horizontal soil shifts.

Pile supports transfer the load coming from the building and the weight of the slab itself to a deep layer of high-density soil, thereby preventing the risk of foundation shrinkage due to insufficient resistance of the surface soil. Due to the fact that the supporting base of the piles is located below the layer of heaving soil, the slab foundation is not subject to the buoyant effects of frost heaving.

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Important: engineering calculations show that about 80% of the total load on the foundation is distributed between the piles and only 20% falls on the reinforced concrete slab. Driven piles of square section from 30*30 to 40*40 cm are used as supports.

The technology for arranging a pile-slab foundation is carried out in the following sequence:

• The foundation is marked - the immersion points of each pile, their zero level (the height at which the piles will be leveled after driving) and the side contours of the slab are marked;
• The piles are distributed to consumable warehouses along the perimeter of the foundation using a jib crane;
• The pile driver moves to the place where the first pile is driven and winches the reinforced concrete structure;
• Auxiliary personnel sling the pile with steel ropes, after which the pile driver lifts the pole and installs it at the driving point;
• The pile is fixed in the guide units of the piledriver mast and mates with the head of the diesel hammer;
• The hammer begins to strike the pile, under the influence of which the structure sinks into the ground. Driving is carried out until the design failure occurs, after which the pile is disconnected from the hammer and the pile driver moves to the next driving location;
• Upon completion of the installation of the pile field, the supports are aligned to the zero level using a pile cutter, while their reinforcement remains intact, only the concrete body of the pile is destroyed;

• Formwork is installed along the perimeter of the foundation, the walls of which are covered with waterproofing material;
• A compacting sand bedding 10-20 cm thick is added. Waterproofing is placed on the bedding and a layer of footing 2-3 cm thick is poured;
• A reinforced frame of the slab is created, to the reinforcement of which the rods protruding from the piles are welded;
• The foundation slab is poured with concrete, after pouring the mixture is compacted by vibration.

Important: Most residential and industrial buildings over 5 floors high are built on a pile-slab foundation - this is one of the most reliable and durable types of reinforced concrete foundations.

Slab foundation pros and cons

A monolithic slab foundation is the most expensive in terms of the amount of concrete and reinforcement used. For this reason alone, it is rarely used in private construction, since every developer strives to save on materials. This is the only one minus slab foundation.

Positive aspects of a slab foundation:

• such a foundation is durable,
• requires a minimum of excavation work,
• located under the entire building,
• protects the building from destruction,
• can bear the loads of several floors of the building being constructed,
• it is not afraid of seasonal temperature changes and ground movement.

Calculation of slab foundation

The calculation of the foundation slab consists of determining its thickness based on the loads that the foundation will experience during operation and the bearing capacity of the soil at the construction site.

Important: according to current SNiP, the minimum permissible thickness of a slab for houses made of medium-heavy building materials - foam concrete, gas silicate, timber and logs is 25 cm, for buildings made of brick - 30 cm.

To collect the load on the foundation, it is necessary to determine the mass of the building, which consists of the weight of the structural elements of the house - walls, floors and roofing.

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You also need to know the bearing capacity of the soil at the construction site. Ideally, this value is determined as a result of geodetic surveys, but if it is impossible to carry them out, you can use the standard table below.

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As an example, we will calculate the thickness of the foundation slab for a two-story brick house with an area of ​​9*9 m with a total weight of 210 tons, built on sandy soil with a bearing capacity of 3.6 kgf/cm2.

• Based on the area of ​​the building and the characteristics of the soil, we calculate the required load on the ground (the total weight of the house and the foundation slab): 81,000 cm2 * 3.6 kgf/m2 = 291.6 tons. If the actual load turns out to be less than the calculated one, the foundation may deform due to unbalanced heaving forces; if the actual load is greater, there is a high risk of soil shrinkage under the weight of the structure;
• We calculate how much weight the foundation slab should have in order to ensure the required load on the soil: 291.6 - 210 = 81.6 tons;
• We determine the number of cubic meters of concrete required to fill a slab of a given mass (the weight of 1 m3 of concrete is 2.7 tons): 81.6/2.7 = 30.2 m3 of concrete;
• A volume of 30.2 m3 with a foundation slab size of 9*9 m, according to the concrete cubic capacity formula, will fill a thickness of 36 cm.

As a result of calculations, we obtain the required thickness of the slab foundation of 36 cm.

Useful materials

Ordering foundation work

And so, if you prefer a tiled foundation to build your house, you need to seek the help of professionals. Our company provides services for the construction of pile foundations to individuals and organizations. Our company’s specialists will take all the necessary measurements for future construction, draw up design documentation and estimates, and also determine the required density of concrete and the reinforcement necessary for construction.

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Our company is engaged in foundation work -

The use of a pile-slab foundation is quite common, since this type of structure foundation is excellent for erecting planting soils on areas. In its own way, the invention is unique because it has increased stability and strength.

A special feature of the slab-pile foundation is that it consists of a grillage, slab and concrete piles. If construction is supposed to be carried out on a site with moving soil, which is characterized by seasonal heaving, the developer cannot find a better option than a pile foundation with a monolithic slab. This type of foundation can be used, among other things, for multi-story construction, since it has a high load-bearing capacity. In addition, a slab foundation on piles allows you to significantly save on arranging a basement or basement. Using a pile-slab foundation, you can reduce the degree of shrinkage of the structure.

What should you pay attention to?

Pile-slab foundations are combined structures that include two types of foundations at once. As a rule, powerful concrete supports are connected by a monolith, which simultaneously serves as a grillage. Thanks to this combination, the pile foundation becomes especially strong and reliable, which attracts many developers.

Despite the fact that the load-bearing capacity of a pile-slab foundation is quite high, before starting work on the construction of the base of the structure, it is necessary to carry out calculations in order to determine the total load on the ground when using two types of foundation simultaneously. When making calculations, the following factors must be taken into account:

• Accurate calculation of the forces that act on each support in the foundation.
• Total stiffness of all piles.
• The nature and degree of interaction of piles buried in the soil with a monolithic slab.
• Possible manifestations of irregularities when placing supports, their uneven location.
• The impact of supports on the soil, as well as their interaction between each other.
• Impact of a monolith on the ground.

When constructing a pile-monolithic foundation, it should be taken into account that the load on the foundation is distributed unevenly. The supports account for about 85% of the total weight of the structure, and the slab itself accounts for only 15%. It is quite difficult to make all the calculations for building and strengthening the foundation yourself. For this reason, it is advisable to contact specialists who will carry out all calculations as accurately and correctly as possible.

Features of operation

A special feature of the combined foundation is that the first step is to build a pile foundation, and then install a monolith on top. The slab better holds the supports together, and also gives additional rigidity, strength and stability to the entire base as a whole. Thanks to this design, there is no need to arrange a grillage, which is usually provided when constructing the foundation.

It is best to install a combined base option in the following situations:

• When construction is located in areas located in areas of increased seismic hazard.
• During construction in particularly problematic areas. For example, these may be areas with heaving soils, underground watery layers and lakes, as well as large depths of soil freezing.

To get rid of the above problems, you just need to ensure the construction of a foundation on piles. Of course, this technology is not suitable in all cases, however, in many situations it will be the only possible option.

In addition, in some cases, a combined base is used to strengthen the supporting belt of the structure. This is necessary for a number of reasons:

1. The use of a slab foundation coupled with a pile foundation is mandatory when constructing extensions to the main buildings that were erected in problem areas.
2. The lack of geological research at the construction site requires the construction of a foundation of higher strength.
3. Combined foundations are used during the construction of buildings sensitive to vibrations.

Foundation technology

To begin with, it should be noted that houses on a combined pile foundation must be built by professionals. It is simply impossible to independently equip such a technologically complex foundation. All work on the construction of the foundation is carried out in strict accordance with regulatory documents for construction, as well as in a clear sequence.

The entire process of constructing a combined foundation can be divided into several stages:

Expert advice:

Thus, combined types of foundation, including both piles and a monolith, are the strongest and most durable. Such foundations are mainly used on more complex soil conditions, where there is a danger that a conventional foundation simply cannot cope. Making a combined foundation is not so easy, but its strength allows you to build a truly reliable building. For the most part, combined foundations are used in multi-story construction, since the strength of the foundation is especially important here. The slightest changes in the base can lead to tilting and deformation of the entire structure.

Screw piles are successfully used in the construction of buildings on problematic soils (quicksand, heaving, deeply frozen and water-filled soils).

This article describes the technology of flooring, types of slabs for performing the technological stage of construction work.

Types and purposes

Ceiling is a structure that divides a building vertically (usually the ceiling is installed above the technical underground and between floors). Floor slabs take up loads from the weight of building elements, furniture, people in the house, and then transfer these loads to the walls of the building.

Floors are usually divided according to their location:

• Underground (basement) – these structures serve to protect the building from the external environment (when building a house on screw foundations), as well as to separate it from the basement, basement or technical underground.
• Interfloor - these floors are installed between the floors of a building during the construction of a multi-story building.
• Attics - necessary in the construction of buildings with attics and attics; their purpose is to separate residential premises from attics.

In this article we will try to find out how to properly arrange a basement floor on a pile-screw foundation (screw piles).

Monolithic floor slab on screw piles: how to arrange it correctly

One of the options for installing a floor on a screw-pile foundation on screw piles is to pour a monolithic slab.

Preparatory work

Before starting concrete work, metal piles should be shortened to the design marks, and the pipe cavity should be filled with concrete mixture. The piles are trimmed in such a way as to remove the holes through which the supporting elements were screwed. When performing work on shortening metal supports, use a hose level.

The length of the piles is initially designed to be larger, taking into account the necessary trimming.

Formwork and concreting

Concrete mixture of class B25 and higher is poured into the cavity of metal piles. Screwed pile screw supports are connected to each other by a welded frame, for which rolled metal (I-beam or channel) is used. The monolithic slab is poured in such a way that the metal grillage with its lower part forms the frame of the future slab. A continuous formwork is installed under the metal frame of the slabs, making sure that there are no gaps in the wooden panels.

The side formwork is erected to the required height, taking into account the expected thickness of the future floor slab. The ground floor floor slab is reinforced with two layers of special reinforcing mesh, after which the structure is filled with concrete mixture. The concrete mixture is carefully leveled over the top of the slab.

Concrete care, waterproofing and insulation

Concrete gains strength in 28 days, so loading the slab during this period is not recommended. In hot weather, to care for the concrete surface, you should periodically spray the flooded structure with water, and also cover it with a protective film.

The formwork from a monolithic floor slab can be removed after 14 days, when the structure has gained up to 70% strength.

The finished floor slab should be carefully treated with waterproofing agents, using the technology of using rolled or coating insulating materials. The most reliable insulation against moisture and condensation that occurs is penetrating waterproofing.

On top of the waterproofing layer, insulation of the surface of the monolithic floor slab should be provided.

Overlapping on screw piles for a log house

The environmental aspect plays a significant role when choosing materials for building a residential building or bathhouse on stilts. If the foundation of the house is made of screw piles, the upper part of the building is very often constructed of wooden materials. Wood is a classic, environmentally friendly building material that has been used for centuries to build bathhouses, residential buildings and outbuildings. How to properly arrange a ceiling in a log house on screw piles? Let's try to understand the technology of installing floors in a wooden building on pile-screw supports.

Technology for constructing a log house floor on screw supports

After screwing the required number of piles (screws) provided for by the project into the ground, the supports should be cut to one level, filled with concrete mixture and the heads of each screw support should be strengthened. The heads are strengthened by welding.

Then you can begin laying the lower crown, for which a wooden beam or rounded log can be used. The cuts for securing the wooden parts are made strictly above the heads of the supporting elements of the pile.

There is another method when screw piles are connected by a grillage belt made of metal. Metal pins are welded along the entire perimeter of the grillage, which during installation must coincide with the drilled holes in the wooden parts of the lower frame of the building. In this case, it is very important not to weaken the support ring with a large number of drilled holes. Waterproofing between metal and wooden parts must be done very carefully. The connecting pins themselves must be treated against corrosion (thickly coated with bitumen).

After this, they begin to lay logs from timber, then erect a wooden floor, which also serves as the floor.

If the log length is over 3 meters, additional support will be required, otherwise the wooden floors will sag and spring.

Floor “pie” (building ceiling on screw piles)

Considering that a building on screw piles has an unprotected space at the bottom and is freely blown by the wind, the ceiling of the lower floor should be properly arranged. To begin with, a load-bearing frame made of wood is laid, which is combined with a subfloor made of wooden boards. Watch the video on how to properly make a ceiling on screw piles.

A layer of film insulation will protect the first floor from heat loss. Then the main heat-insulating layer is laid, which is covered with rolled film materials to insulate it from moisture and steam. The completion of the layered “pie” of the floor, combined with the floor, is the finishing boards.

The following materials are used for floor insulation:

• Sheet foam - sheets of material are laid on the subfloor. It is worth noting that if there is insufficient insulation from moisture and low temperatures, the foam is easily destroyed, breaking up into small segments. In general, sheet foam, as insulation, copes with the task perfectly.
• Mineral wool insulation is offered for sale in the form of individual mats or in rolls. Mineral wool can be slag, glass or stone - all types are perfect for insulating the floors of buildings on screw piles. The material should be protected from moisture.
• Penoplex, expanded polystyrene - materials ideally protect building structures from freezing and high humidity. Insulating the floors of buildings on screw piles with polystyrene foam or penoplex is the most reliable method available today.

When choosing the type of foundation for a future country house, you need to carefully study the condition of the soil on the site. After all, the durability of the building directly depends on the strength of the foundation. You also need to take into account that in the near future, family circumstances may require an expansion of the living space, and the building will have to be built with one or two floors. This means that it is necessary to design the foundation with a very large margin of safety. But what to do if the hydrogeology of the site leaves much to be desired (unstable soil, abundance of surface groundwater, seasonal flooding, etc.)?

A good solution in this situation would be to install a monolithic slab on bored piles. The piles go through all the weak layers and sink into the dense soil, transferring the entire load from the house to the solid soil, and the heavy slab will successfully resist the displacement of unstable soil layers, in this case the bored piles work as racks. If strong soil lies deep or is absent at all, bored piles will work like hanging piles due to lateral friction. In addition to reliability, such a foundation is characterized by low cost, which is important for private construction.

The construction of the foundation begins in the standard way - by calculating the required number of piles, determining the required depth of their immersion (at least one and a half to two meters is recommended, depending on the depth of freezing), drawing up a diagram of their location and marking the area. As a rule, piles are installed in the corners of the house and in the middle of each side; the number of bored piles can be approximately determined by collecting permanent and temporary loads from the building and the monolithic slab. There are tables of the load-bearing capacity of bored piles depending on the type and density of the soil, as well as the diameter of the base of the piles. Next, inside the perimeter of the future foundation, the vegetation layer is removed and the surface is carefully leveled; if possible, it is better to use an excavator for this manipulation.

After completing the preparatory stage, holes for piles are drilled in the ground using a hand drill. Then crushed stone is poured onto the leveled surface, after which it is compacted with manual or electric tampers so that the thickness of the backfill is fifteen to twenty centimeters.

To compact crushed stone, you can use a vibrating plate running on diesel fuel or gasoline. Next, wooden or metal formwork is assembled around the perimeter. At this stage, it is necessary to provide the necessary communications - to design and place the input of the water supply system and the output of the sewerage system.

Now you need to prepare the reinforcement for the support piles. It is knitted from longitudinal rods of a periodic profile with a minimum diameter of twelve millimeters, which are fastened in the transverse plane with round clamps made of metal wire approximately every thirty centimeters in length. The number of longitudinal rods must be at least six, the rods must be evenly spaced around the circumference. The result should be a cylindrical structure, the diameter of which should be 100-140 millimeters less than the diameter of the holes for the piles. To waterproof a bored pile, even in relatively dry soils, it is recommended to make a pipe from roofing material (with an overlap of up to 0.5 meters), tied with wire and lower it into a drilled hole. The number of layers and type of vertical waterproofing depends on hydrogeological conditions. It is always better to apply 2-3 layers of waterproofing at the top of the pile. The associated reinforcement (structure) is lowered into the wells and filled with concrete of a grade not lower than 200 (B15).

It should be noted the obvious advantages of using vertical waterproofing in the form of a pipe made of roofing felt:

1. A pipe inserted into a well perfectly serves as a formwork when concreting a pile.
2. The setting of concrete and strength gain improves, since the cement laitance will not go into the ground and the strength of the concrete will not decrease.
3. In dry soils, when concreting, water, so necessary for hardening the concrete, will not go into the ground and therefore the strength of the concrete will not decrease.
4. When the soil freezes, the forces of frost heaving will have less effect on the rough body of the piles, in the presence of roofing material!

It's time to pour the so-called footing - a thin rough layer of concrete mixture under the main foundation. It performs several functions: it provides additional waterproofing of the main foundation slab, performs preliminary leveling of the surface and creates a plane for convenient marking and installation of the reinforcement cage. For the footing, concrete of a grade of at least 200 (B15) is used; it is better to produce it with a rented mixer. The thickness of the concrete layer is usually at least ten centimeters.

Reinforced frame of a monolithic foundation slab

The concrete needs to stand for three to four days, after which markings are made on its surface for reinforcement. The reinforced frame is made from reinforcement rods in the form of a set of square cells with a side of twenty to forty centimeters, interconnected by metal wire. The diameter of the rods for the frame is selected in the range from twelve to fourteen millimeters. The reinforced frame, which consists of a lower and upper grid on spacers, is installed on the rough layer of the concrete. The lower grid (mesh) of the slab is laid on the concrete preparation on special protective layer clamps “chairs” or “cubes” to ensure a minimum thickness of the protective layer of concrete of 35 mm. When there is no concrete preparation under a monolithic foundation or slab, the thickness of the protective layer of concrete for the lower grid must be at least 70 mm. Next, using the same mixer, the slab is poured with a layer of concrete grade no lower than B22.5, thirty to forty centimeters thick. This is how the main monolithic foundation slab is formed.

The main layer of concrete is allowed to settle for several days under the protection of plastic film, after which the entire surface of the foundation is cleared of debris, dust and dirt, treated with two waterproofing materials: first, a layer of special mastic (primer) is applied, and a day or two later (after the first layer has dried) ) – cold bitumen primer. The construction of the foundation is completed. Now it again needs to be protected from the effects of precipitation with any waterproofing film and left to harden for three to four weeks, during which it must absolutely not be subjected to any load.

The combination of a concrete monolithic slab and bored piles, in addition to solving certain construction problems, allows you to save a lot on construction without sacrificing quality. For example, a similar foundation with an area of ​​sixty square meters at average market prices will cost about one hundred and fifty thousand rubles, including the rental of the necessary equipment (an excavator and a mixer for pouring concrete).

If you get a suburban area with problematic soil, you shouldn’t despair. A monolithic foundation on bored piles will allow you to build a reliable and spacious house that will stand for many years.

Attention! The thickness of a monolithic foundation slab and its reinforcement, as well as the quantity, diameter, percentage of reinforcement and length of bored piles depend on the construction area, the load from the building (its number of storeys and design features), the type of foundation soil and hydrogeological conditions at the construction site! In addition, it may be necessary to perform waterproofing for concrete preparation and horizontal or vertical insulation of a monolithic slab foundation!

Foundation, monolithic slab on bored piles

Foundation on bored piles: design requirements, preparation of the site and foundation for pre-concrete, pits, waterproofing, creation of reinforced frames for the slab and piles, pouring the foundation slab

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Today, the construction industry is developing quite quickly.

For the stability of buildings and structures for various purposes, a foundation is pre-built.

The base is divided into several types, which differ from each other in design, construction method, and characteristics.

One of the most common types of foundation is. It is often combined with other types in order to improve sustainability and other indicators.

A slab foundation for individual houses and various buildings is called durable monolith made of reinforced concrete or concrete. Walls are built on these structures.

To his main include the following:

• intended to create a solid foundation in areas with problematic soil, which is characterized by fairly high mobility;
, therefore, as a result, a small specific pressure is created when calculated per square meter;
• is different long service life;
• monolith with reinforcement has high strength;
• slab foundation surface can be used as a base for the floor in a buiding;
• With such a foundation, houses can be built on plots where the groundwater level is too close to the day surface. In addition, it is preferred in wetlands and places with heaving soils;
• helps prevent possible deformation of the base of the building.

Slab foundation design is simple and reliable. To create it you need to perform the following steps:

1. Conduct on the basis, taking into account the features of the structure design and the natural conditions of the territory.
2. Take into account depth of freezing of the soil layer.
3. After receiving the calculation results choose the most suitable type of slab foundation.
4. Use concrete and special reinforcement, which comply with all requirements and construction standards - SNiP and GOST.
5. Implement placement depth calculations grounds.
6. Determine whether it is necessary to apply additional reinforcing elements.
7. Create a project and then a structure drainage system.
8. Take care of creating a durable pillow between the soil layer and the slab.

Foundations combined with a monolithic slab

Pile-slab

The slab-pile foundation is one of the most unique inventions intended for use in the construction industry.

As a rule, a combined pile-slab foundation is used during the construction of large-scale multi-story buildings. It should be noted that a slab foundation on piles consists of several important elements: reinforced concrete piles and grillage, which are characterized by increased strength and resistance to fairly large loads.

The main difference between a pile-slab foundation is its ability withstand adverse natural phenomena over a long period of time. That is why it is being built in dangerous areas with difficult terrain and high levels of seismicity. After all, such structures are designed to provide reliable protection against vibration vibrations.

This type of foundation consists of two components (a slab on a pile foundation and the piles themselves), which are the load-bearing elements of the foundation that meets all quality standards. Thanks to their presence ensures that the load is transferred directly from the structure to the soil of a strong foundation.

With a monolithic slab you can apply in the following cases:

• if the construction of buildings on bulk and soft soils is required;
• when tightly adjacent to pre-created foundations;
• if calculations have shown that the compressibility of the base will be uneven, then additional reinforcement piles are used to help level out the uneven settlement of a particular slab;
• if builders do not have true information about the characteristics of the soil layer in a certain area.

Advantages pile-slab foundation:

• strength;
• reliability;
• Suitable for different terrain;
• constructed in a short period of time;
• can withstand quite heavy loads.

Important! You need to be careful when choosing piles, because they are one of the load-bearing elements.

Pile-grillage

Nowadays, a pile-grillage foundation with a monolithic slab is quite popular.

This is due to his increased reliability and low cost of installation work. Its design is a durable monolithic slab, which ensures the connection of all pile heads along the perimeter of the building.

The stove should be either at ground level or slightly higher his. The main task of the design is to evenly distribute the heavy load that is created by the erected building throughout the entire site.

This type of foundation has a whole list important advantages:

• houses can be built on almost any territory, regardless of the features of its topography and soil type;
• the design has a fairly large margin of safety;
• it can be built at a short distance from the groundwater level;
• resistance to freezing or swelling of the soil layer;
• foundation construction work takes relatively little time;
• is much cheaper compared to many other options;
• the only suitable option for areas with very difficult terrain.

Necessary choose piles very carefully, because even a minor flaw will significantly deteriorate the performance of the entire foundation.

Important! You need to have special knowledge and skills to properly build a reinforcing frame, connect it to the supports and fill it with mortar.

Columnar

It is no less popular with a monolithic slab. This is a structure that consists of solid reinforced concrete pillars filled with concrete mortar.

On top of them is a durable slab, which often serves as a subfloor..

Advantages:

• good stability;
• suitable for almost any terrain;
• withstands very heavy loads;
• a building built on this foundation has a long service life.

Flaws:

• high cost of work;
• the construction of such a foundation takes a relatively long time;
• in order to correctly perform the entire technology, it is necessary have the appropriate skills and abilities.

Tape

with a slab has the form of a reinforced concrete strip constructed along the entire perimeter of the building being constructed, on top of which a monolithic concrete slab is placed.

His the structure consists of reinforcing mesh filled with concrete, sand and crushed stone cushion and slab.

The base is suitable for the construction of buildings for various purposes on one or several floors in areas with dense soils.

TO benefits The following features include:

• increased strength;
• possibility of construction on almost all types of soil;
• long service life;
• suitable for buildings of any purpose;
• a monolithic slab is used as a subfloor.

Disadvantages strip foundation with a monolithic slab can be called:

• before its construction it is necessary to carry out rather complex calculations;
• requires a large amount of materials;
• the relatively high labor intensity of the construction process;
• when preparing a pit it is necessary to perform a large amount of earthwork;
• quite expensive option.

Monolithic slab on a strip foundation: construction technology consists from several stages:

1. First you need carry out geodetic exploration of the territory.
2. Determined axis of the future building.
3. Carefully the vegetation cover of the area is removed to a depth of approximately 30 cm. There is no need to remove the soil.
4. The bottom of the prepared pit is completely covered with special geotextiles so that the sand does not mix with soil particles in the future.
5. Making a sand and crushed stone cushion, the thickness of which should be about 20 cm. It will become tape base.
6. Necessary install pipes according to the projects of the building's water supply system and sewerage system.
7. Created formwork using panels made of durable wood.
8. Then it gets settled sand and crushed stone cushion for a monolithic slab average thickness up to 35 cm.
9. Strip foundation: slab reinforcement is one of the main stages. Have to take reinforcing rods, the diameter of which is determined depending on the degree of expected load on the base. In most cases, rods with a diameter of 1.2 cm are used.
10. From the twigs two separate meshes are made, connected using small jumpers. The pitch of such a mesh should be about 30–40 cm (the heavier the structure, the smaller it should be).
11. All the rods are connected thanks to a knitting machine or welding machine.
12. The finished frame is installed on top of the stands(foam blocks or bricks) so that it does not touch the ground surface.
13. Next step - filling the structure with mortar. How to pour a monolithic slab onto a strip foundation correctly? You should use concrete grade M300.
14. In order to increase the strength of the foundation and prevent the occurrence of voids in it, it is recommended install special deep vibrators.
15. After the solution has completely hardened, you should carefully remove the formwork. Do-it-yourself monolithic slab on a strip foundation is ready.

According to this scheme, the MZFL slab foundation is made - a shallow strip foundation with a monolithic slab.

Useful video

Additional information about a monolithic grillage on a pile foundation is presented in the video below:

conclusions

Slab foundation is one of the most popular types of foundations for various buildings. It has good characteristics.

In order to improve its properties, combined types are now used, which differ from each other in construction technology, indicators, and are intended for construction on different soils.

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