Pouring the foundation setting time. Is it possible to fill the foundation in parts? Strip poured foundation

When performing construction work of any volume, the foundation is an integral part of any structure. The reliability and strength of the future home depends on it. There are several types of bases for a building, and there are differences in design. Many people are also interested in whether it is possible to fill the foundation in parts.

Types and arrangement of foundations for private construction

There are several types of structures for the construction of private houses and other low-rise buildings:

• ribbon design;
• slab;
• columnar;
• pile

Basic belt type design

For this scheme, at the beginning of the work it is necessary to set up the formwork with a special reinforcing belt, and then pour in the solution. These are all the main parts of the foundation.

About filling in layers

On large construction sites, it is customary to pour concrete immediately in the required quantities. But what should frequency homeowners builders do? Of course, you can get by with a concrete mixer, but there is a problem with limited volumes of the mixture. How to fill a strip foundation in parts? How will this ultimately affect the characteristics of the structure?

In the case of a monolithic base, the seam can be located both vertically and horizontally. In order to get a solid foundation as a result, you need to take care in advance that the components of the foundation are completed according to all the rules. Thus, it is desirable that the reinforcement be done as efficiently as possible, and that its direction be perpendicular to the joint of the monolithic block.

If the seams are in a vertical plane, then the reinforcing parts located longitudinally will reliably connect the corners. If it is assumed that the work will be done in parts, then it is imperative to install vertical reinforcement.

But in fact, on most construction projects the strip base is poured in layers. This is because the vertical pouring technology requires the installation of additional formwork.

If you need to make a strip foundation in parts, then you should definitely know one important nuance. If the formwork is only above the ground, and the underground structure will be poured into a prepared trench, then it is advisable to make the joints at the soil level.

Before the basement part of the foundation is built, you need to wait for the mixture to harden on the first layer. This often takes about two days.

About the setting time of concrete mixtures

Setting is the first thing that happens after pouring. It can be characterized as a gradual combination of the components of the poured solution. If the integrity is compromised during these processes, the concrete mixture will lose its structure.

How long does it take for minimum setting? For most concretes this is about 3 hours. The period depends on the air temperature. Under the worst conditions, this time can last for a day. This is true for the winter season. The warmer it is, the faster the mixture will harden. But this is only the beginning of the hardening process. The structure will still be liquid.

If the lower part of the foundation has frozen for 8 hours, then you can pour in another layer and it will be safe.

Hardening process

These processes can last for a month. But you can proceed to construction work only after the mass has completely hardened. When the solution begins to harden, another layer is poured only after three days have passed.

So. From all this it follows that if the foundation is poured in parts in winter, then the next layer can be added no earlier than after 8 hours. In summer - every 4 hours. If another layer is expected after maximum hardening, then the previous one needs to be thoroughly dried.

How to fill

The first layer is poured as evenly as possible. It is imperative that it be filled with one stream. If you fill from different angles, then you will not be able to achieve uniformity - the result is a crooked base element.

Now you should compact the resulting material using a vibrating tool and level it. After maintaining the hardening interval, you can proceed to the next stage.

Pouring the tape base in several steps is not only convenient and economical, but also reliable, durable and of high quality.

Foundations on piles

Where the soils were flooded, people built houses on so-called pile buildings. These are some of the most time consuming ways to create a foundation. Today, this scheme is used for construction on soft soils.

Disadvantages and advantages

Although this scheme seems overly complicated, it has many advantages:

• high construction speed and time saving;
• minimum amount of ground work;
• you can work whenever you want;
• minimizing the cost of the building.

There are also pile foundations with a so-called grillage. This is a special technology designed to increase reliability. The design of the upper part of the pile foundation is carried out using one of two technologies. A distinction is made between a pile-strip base and a pile-slab structure.

It is possible to make grillages from various reinforced concrete products or to fill a monolithic mass from mixtures. The first method is available for industrial facilities, and the second is an excellent choice for private builders and a way to construct a building with your own hands.

The disadvantage is the complex design of the base. So, the space between the soil and the grillage must be filled.

Construction based on piles and grillages

This is one of the types of pile-and-tape buildings. The tape here will be slightly higher than the soil surface. Construction includes drilling wells for piles.

To make such a foundation, it is advisable to use special heavy concrete with quartz sand. The supporting part of the foundation can be made in several layers. Then, after three days, you can proceed to the installation of the grillage.

This step includes several main steps:

1. installation of formwork on piles;
2. installation of fittings;
3. filling.

The height of this part should be approximately 300 mm. The width is slightly greater than the thickness of the walls. The upper part of the foundation can be made in parts, in several layers.

Technology for the construction of basic types of foundations

From afar, for people far from construction, the process of pouring concrete looks the same for the main types of bases for buildings. It seems that the concrete is simply fed through a special sleeve and completely fills the cavities. But everywhere there are certain nuances. And building a foundation in parts also has its own peculiarities.

For example, it is much easier to design piles than to create a base for a structure based on tape. With the belt method, the process of pouring into several layers will be the optimal solution, and then after a certain technological period you can move on to another layer. In the case of piles, the concrete mixture is fed into the hole for each pile.

In the case when a slab part of the foundation is being built, then it is prohibited to use such technology. The material is dumped into a pile, and then it is simply leveled. But this operation must be carried out as quickly as possible - within 30 minutes.

Repair work

Sometimes there comes a time when the basic level requires renovation. It is much easier and cheaper to make a new base part. Replacing the foundation in parts will cost significantly more than a complete replacement. But you can try pouring the mixture into several layers.

In general, the entire repair consists of digging a trench around the perimeter and cleaning out cracks. Then you should use anchors to strengthen the reinforcement and proceed to pouring a new solution. This will strengthen the current base and stop cracking.

When the work of pouring the first layer is completed, it is necessary to cover it so that the hardening and hardening processes take place more efficiently. This will also protect the flooded area from rain. There must be air gaps at the edge.

Before pouring the foundation in parts, it would be a good idea to prepare a sketch of the future foundation on a sheet of paper. You need to indicate on this sheet the time when you completed the first layer. This makes it easier to keep track of time intervals and easier to avoid mistakes with subsequent layers.

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In the manufacture of various types of monolithic foundations, a large volume of concrete mixture is used, which, according to existing construction standards, is recommended to be poured in one go. Thus, a strong and reliable one-piece monolithic structure is obtained. However, when building a private house and arranging a strip or slab foundation, it is technically difficult to ensure a continuous pouring process due to many conditions: lack of labor, insufficient volume of concrete, unreliability of suppliers, etc. Therefore, many developers, even at the stage of preparing the property, ask themselves the question -?

The current construction standards (SNiP) provide for several options for pouring monolithic foundations with time intervals. The main thing is to familiarize yourself with all the recommendations in detail and follow them in strict sequence.

Foundation division scheme

Before the start of general construction work, taking into account the type and characteristics of the foundation, its size and scope of work, a pour division diagram should be drawn up. According to approved standards, the following methods for arranging butt seams can be used:

• Vertically. The foundation structure should be divided into several parts. They are separated in advance, before pouring, using metal partitions. When choosing this pouring method, the joining points of the concrete composition are marked on the drawings. After one section of the monolith has hardened, the partitions must be removed and only then pouring continues.
• Horizontally. The entire monolithic foundation is conventionally divided into several parts according to its height. In this case, partitions are not used. It is enough to determine the optimal depth of one fill. Typically this method is used when constructing a monolithic strip foundation. The joint is usually marked at ground level.
• Diagonally. The most difficult filling method. Typically used in the construction of large objects and pouring large volumes of concrete mixture. The hardest thing is to give the joint a certain amount of slope. Typically this is 45 degrees.

Attention! The joining seam in a monolithic structure should not fall on the reinforcement ties. It is performed below or above the steel reinforcement!

Important conditions for phased filling

Having clarified the question - Is it possible to fill the foundation in parts?, you should also learn how to technically carry out this process without losing the quality characteristics of the building’s base. There are two ways to join the fill:

• "Cold seam" If the construction of a monolithic base is interrupted for a day or more, then you should wait until the concrete has completely set and hardened.
• "Hot seam" During a short-term break in pouring (up to 12-18 hours maximum), the concrete surface is covered with roofing felt or thick plastic film. Under the concrete coating, “concrete milk” will be released, which prevents the formation of a hardened crust. This way, the concrete will not have time to dry and the pouring process can continue.

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The durability of any building depends on the reliability of its foundation. What kind of soil, what height of the building it will support, what kind of foundation to choose for a given building - all these questions are important for the strength of buildings. But often when deciding to build a building, they decide on their own only what type of foundation will be chosen

A strip foundation does not require special equipment for delivery to the site, which is why home craftsmen prefer it.

For buildings in suburban areas, block or strip foundations are most often used. The first ones require special equipment: they must be somehow delivered to the site, somehow lifted for installation on site. Therefore, home craftsmen give preference to strip foundations. So that the source material can be delivered to the site without much difficulty.

Preparatory work

The width of the trench channel prepared for installation of the foundation of the building is 40 cm.

So, you need to pour concrete by installing a strip foundation. All work of the previous stages has been completed: the area has been cleared and marked according to the project. The trench must be prepared for the installation of the foundation of the building. The optimal channel width is about 40 cm. A 15 cm layer of sand is poured and compacted onto the bottom, then a layer of crushed stone is laid. Waterproofing made of roofing felt or plastic film is placed on top of the resulting cake. After this, you can begin constructing the formwork. It is assembled from available materials. It should rise above the ground surface by at least 30 cm. All sewer openings and water pipes must be provided in advance. The reinforcement is laid in two layers in the form of a lattice, fastening the rods with wire. To ensure that the entire structure is inside a concrete monolith, a 5 cm indentation from the formwork walls is provided along the entire perimeter.

You can determine the required amount to fill. To do this, we find the volume of the internal part of the formwork by multiplying its height, width and length. The mortar recipe consists of three parts sand, five parts crushed stone and one part cement. Water is added in parts until the required consistency is obtained. However, it is unlikely that you will be able to prepare the required amount for a one-time filling yourself.

First way

According to SNiP 3.03.01-87 “Load-bearing and enclosing structures”, two laying methods have been developed for monolithic concreting.

The first method, called a “hot seam,” consists of pouring without interruption until the previous layer begins to set, that is, without forming a working “cold” seam.

To do this, you can take a break from pouring concrete for no more than twelve hours. The resulting layer is covered with film or roofing felt at night. Before continuing the pouring, the whitish liquid formed overnight, the so-called concrete milk, is removed from the surface of the previous layer.

Second way

The method of pouring concrete with the formation of a “cold” joint allows you to stop pouring concrete for a longer period.

The second method involves pouring intermittently after the previously laid layer has set, forming a working “cold” seam. Such seams are also called construction seams, working seams and concreting seams. This method allows you to stop pouring for a longer period than one night. But in this case, you should wait until the previous layer has completely hardened. If you pour on a poorly hardened layer, you can get a surface that begins to break, unable to withstand the pressure. The concrete of the joint will become brittle, and the formation of cold bridges that can conduct water will be ensured. Subsequently, such bridges will cause the destruction of the structure’s support. Before pouring the next layer, the surface of the resulting joint is cleared of any dirt or cement film. This will reduce the negative impact of construction joints.

The same SNiP 3.03.01-87 allows not only layers, but also parts. In this case, the working seams will be vertical. To form them, partitions are installed, like formwork.

Fill options

The height of the level of concrete poured into the formwork should not exceed half a meter.

After installing the formwork and calculating the required amount of concrete, you can determine the method of pouring the foundation, as well as the amount of time this work is expected to take. It is more rational to order concrete from a factory and pour the foundation from a machine and not alone. But is there room on the site for machines to operate? Is it possible to order all the necessary equipment within the time frame required to continue the work?

The foundation formwork can be added in layers of about 20 cm. In any case, the height of the level should not exceed half a meter. Each layer is distributed evenly along the entire perimeter of the formwork and along its entire length. To prevent voids from forming, the poured layer is compacted. Tamping is completed when a white liquid appears on the surface of the layer. The walls of the formwork are tapped. These actions are designed to remove air from the concrete and prevent the formation of voids in the monolith. The procedure is carried out until the layer reaches the level of the fixed rope, which indicates the height of the “sole”. After this, the surface is leveled with a trowel. The fittings also make several punctures to release air. The formwork is tapped again.

Quite often when building a house, the following question arises: is it possible to fill the foundation in parts? And how to fill it correctly?

“Cold or hot” seam?

Formwork for the foundation

It is almost impossible to manually pour the foundation yourself at one time, especially if the foundation is large enough. But what to do in this case? There may be two options.

The first is as follows. First, continuous pouring is carried out, after which a break is made at night (for about twelve hours). In this case, a horizontal layer is poured over the surface of the formwork, after which the concrete is covered with film or roofing felt.

The layer under the coating will not have time to harden overnight, and in the morning the so-called milk of concrete will be washed off from the surface. If it comes out, then the filling continues. This method is called “hot joint”, since the layers of concrete do not have time to dry.

The second method is “cold seam” installation. In this case, the filling is interrupted for more than a day. In this case, it is necessary to pour concrete only when the previous layer has completely dried and hardened. It is impossible to pour the foundation on a barely hardened layer. This is due to the fact that during a break, the bottom layer begins to crust over.

When fresh soft concrete begins to fill the previous layer, the crust begins to break at this point, unable to withstand the pressure. As a result, a layer with a crumbling and brittle area appears at the seam site. And this affects the quality of the foundation, because it is the foundation of the house and must withstand significant loads.

We divide the foundation into sections

In order to answer the question of whether it is possible to fill the foundation in parts, you first need to decide how exactly and into what parts the foundation itself can be divided. There is no clear answer here. You can divide the foundation in several ways:

• Horizontally. When the filling is approximately half the height;
• Vertical. At the same time, with the help of vertical partitions, the entire foundation is divided into separate sections, which are poured gradually;
• Diagonally. In this case, the partitions are installed at an angle of forty-five degrees.

From formwork to pouring

So, is it possible to fill the foundation in parts and how exactly to do it? We follow the following stages of work:

• We make formwork;
• We choose the pouring option: “hot” or “cold joint”, depending on the period over which the foundation is planned to be poured;
• Prepare materials for the mixture (sand, cement, crushed stone) and a concrete mixer for mixing. It is also necessary to consider how long the chute is needed to supply concrete;
• We divide the foundation into zones for pouring:
• Horizontal (then the concrete will be laid in separate layers);
• Vertical (using vertical partitions, the formwork is divided into parts that will be poured from the bottom to the top of the foundation);
• Diagonal (in this case, the partitions are not installed vertically, but at an angle of forty-five degrees).

The concrete mixture for pouring the foundation is carried out continuously, while one part of the mixture is mixed, the second is gradually poured onto the selected area. The poured mixture must be evenly distributed over the entire surface of the layer.

After pouring, we begin to compact the concrete using an internal vibrator or manually with reinforcing bars. The depth of the layer using the manual method should be about twenty to thirty centimeters;

It is necessary to pour the foundation without haste, carefully and thoroughly. After this, it must be covered with plastic film and roofing felt for preservation and protection from precipitation.

Stages of pouring the foundation

So, let's start pouring the foundation. To begin with, we determine the correct division of the entire site into separate parts. Then we prepare the concrete solution using a mixer. If the volume of work is large enough, a hand mixer will not work here; you can rent a large one.

After preparation, we begin pouring. Along a trench about twenty to fifty meters long, we begin to slowly and gradually feed the mixture into the formwork. At the same time, you should not pour the foundation in only one place, since then it will be very inconvenient to rake it and distribute it evenly over the selected area.

Also, the concrete may delaminate, i.e. its more liquid part will accumulate in the corners and distant areas, and the thicker rocky part will settle in the place where the pouring itself takes place. To prevent this from happening, you need to move the mixer to different places around the foundation.

If this is impossible or inconvenient for various reasons, the concrete supply chute can be extended using simple boards and plastic film or a piece of linoleum lined at the bottom of this improvised chute.

You can also order a large concrete pump, which will arrive at the site with already prepared concrete. The length of its gutter is sufficient to reach any corner of the foundation. However, this method justifies itself when building a very large house; for a small country house it is not advisable.

Pouring a columnar foundation

When pouring, you can also use a household concrete mixer, which is slightly larger than a manual one. In such a device, the concrete mixture is mixed quickly and efficiently, which fully meets the requirements of pouring. One batch in such a concrete mixer can produce from fifty to two hundred liters of solution, which is enough for the foundation of a country house.

With the latter method, however, the work may take a long time. One cube of concrete may require about 20 mixing cycles (for a fifty-liter concrete mixer). One cycle takes approximately three to five minutes of mixing and ten to supply sand, cement, crushed stone, and then transport the concrete to the foundation.

With this option, filling may take two days. Then the “hot seam” option is used here. After complete filling, we carry out compaction.

It is necessary to fill the foundation in parts correctly, following a few simple recommendations.

• When pouring horizontally, you cannot make a seam where the reinforcement frame passes through. In this case, it is necessary to fill either below or above this joint;
• The fill layers should not be very thin. If there is not enough time, then it is better to carry out vertical filling in small portions. In this case, the vertical seam will be stronger than many thin horizontal ones;
• Concrete must be compacted when pouring to remove air bubbles. Two methods can be used:
• Professional, which involves using a deep vibrator, lowered into concrete for a couple of minutes. When it works, bubbles constantly appear on the surface. It is necessary to ensure that the vibrator does not touch either the reinforcement belt of the foundation or the formwork. The range is fifty to seventy centimeters. The device is gradually transferred to a new area;
• Amateur way. With this method, concrete is compacted by bayoneting. After pouring a shallow layer of twenty to thirty centimeters, a metal rod is used to consistently pierce the concrete in increments of one to two centimeters. You can also additionally hit the formwork itself with a sledgehammer.
• After all pouring and compaction, the concrete must be covered with a film from the sun's rays. You can water the surface of the concrete several times a day, then it will dry evenly (the inner layers dry more slowly). The first days the concrete is watered up to four times, from the third to the seventh days - only three times a day.

The foundation must dry for at least twenty-eight days, only after which you can begin building the house.

To build a foundation, a large amount of ready-made concrete solution is required. At large industrial facilities, this issue is resolved by using special equipment, with the help of which concrete is fed into the formwork.

In the private construction of a country house, the only available tool is a concrete mixer. The volume of solution per load in this case is small. Therefore, many people ask a logical question: is it possible to fill the foundation in parts?

When starting to pour the foundation in parts, you should study the technology of setting and hardening of concrete.

Hardening of concrete takes place in two stages:

• setting
• hardening

Each of them has its own time frame. First, poured into a trench equipped with formwork, the concrete composition goes through the first stage - setting. The components, namely cement and fillers (sand, crushed stone and others) begin to combine. At this time, it is extremely undesirable to touch the concrete solution, so as not to violate its integrity. This stage lasts in dry and hot weather up to three hours, and in the rainy autumn period up to 24 hours.

The composition remains liquid, which allows you to fill it in small parts. Work can be carried out no more than a day.

Then the concrete solution hardens. This is a longer stage, lasting up to 4 weeks. Only at the end of this period is the concrete ready to withstand the necessary loads.

During the first 3 days of hardening of the solution, it should absolutely not be touched or new layers should be poured. Then you can pour additional layers of concrete onto the finished, hardened surface. If this rule is violated, then under the influence of additional load, uncured concrete can develop many microcracks through which water will penetrate.

Filling times at sub-zero temperatures and in summer are slightly different. In the summer, when the temperature outside is high, each subsequent layer of mortar, at the setting stage, can be poured after 4 hours. In winter this period is 8 hours.

When pouring the second layer of solution after complete drying, the surface must be cleaned with a brush to remove dust and dirt.

Having decided that the foundation will be poured in parts, it is important, using step-by-step instructions, to distribute portioned layers of concrete that will be joined together. Docking seams can have the following types of location:

• horizontal
• vertical
• at an angle

This issue is regulated by existing SNiPs, which contain recommendations. The seam between the layers of the monolithic base must be located perpendicular to the axis. For example, to pour vertical columns, pour concrete with horizontal layers.

A strip monolithic foundation for a house can be poured using both horizontal and vertical seams. Its strength is achieved by constructing formwork with reinforcement. Proper reinforcement involves directing the rods perpendicular to the seams.

When pouring vertically layer-by-layer, longitudinal reinforcement of the corners of the building must be done. If layer-by-layer horizontal filling is used, the formwork is tied vertically with reinforcement.

When installing formwork only above the ground surface (the underground part is poured directly into the trench), the joints of the layers are made at soil level. Before they begin to pour the above-ground part of the foundation into the formwork, the concrete in the trench must completely harden. This will take several days. Otherwise, the mass of freshly poured concrete will destroy the uncured lower layer with its weight. Microcracks may appear on its surface, which will lead to destruction of the base.

When pouring a slab foundation, the layers should be placed perpendicular to the short side of the slab. Arranging the seams in this way reduces the possibility of damage to the foundation under loads.

Advantages and disadvantages of partial foundation pouring

Partial pouring of the foundation has a number of advantages:

• Possibility of carrying out work without the use of special heavy construction equipment. Access to private construction sites is difficult for special construction vehicles. All that remains is to fill the foundation in parts using a simple concrete mixer.
• Possibility of stopping the construction process. Sometimes a situation arises when you need to take a short break in construction. In this case, partial pouring of the foundation is an indispensable method. Using it, you can save building materials and quickly resume work.

It should be noted the disadvantages of this method of constructing a foundation. What does this mean? Firstly, it reduces its strength. Carrying out work in violation of technology leads to the appearance of cracks and destruction of the foundation. By completely pouring the base of the house, a monolithic structure is obtained that has great strength characteristics.