Monolithic area between the slabs. Monolithic sections between floor slabs

Comments:

Building a house is a very laborious task, which includes quite a lot of work. For example, pouring a monolithic section between floor slabs is also one of them, since construction from only slabs is not possible. This problem, as a rule, arises in cases where it is required to lay communication elements or form a flight of stairs. It should be noted that adhering to certain rules construction, you can carry out this process yourself.

When creating monolithic floor sections, it is necessary to correctly install the support, form the formwork, reinforcing mesh, make a mixture of concrete and pour it.

At correct execution of all the listed works, the section of the monolith between the floor slabs will be as strong and reliable as possible.

Materials and tools required for work

For each stage of work, you must prepare your own set of materials and tools. Their list may differ only due to some factors, for example, the distance between the plates, which needs to be poured. However, there is still a standard list that includes the following materials:

The area between the floor slabs is filled with concrete, pre-reinforced.

boards that will be used to create side formwork and surfaces;
wooden beams or metal channels, which will serve as a support for plywood or a board pallet;
timber for creating bearing supports for the formwork platform;
reinforcement rods, wire with which the bundle will be made, metal chairs;
concrete solution, which is made from sand, M400 cement, crushed stone and water;
concrete mixer;
circular saw, shovel, trowel, bayonet and protective film.

As for the amount of material, it depends on what kind of overlap area needs to be done, as well as on the overlap area itself. If we talk about a private house, then in such buildings, as a rule, it is not very large, so it will not be difficult to cope with the work on your own.

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Stages of forming a monolithic overlap area

The formation of the area between the slabs is no different from the creation of any other. Despite the fact that the area of work is relatively small, adhere to building regulations is still worth it, so all stages of the work must be performed carefully. It depends on this how reliable the monolithic structure will be.

The first thing that needs to be done is to form a formwork for a monolithic area. In this case, it is necessary to take into account the fact that the concrete solution weighs quite a lot, moreover, it dries for a long time, therefore the strength and mechanical characteristics of the formwork must be such as to keep it for a rather long period of time.

How the formwork is installed:

Formwork for a monolithic area between the slabs

The bottom is made, for which a sheet of plywood is taken, and beams are stuffed onto it, which will play the role load-bearing elements... Since the distance between the slabs in a private house is not so great, it is not difficult to make the bottom of the formwork. Before forming the reinforcement lattice, we cover the bottom with roofing material or construction film.
The boundaries of the monolithic section on the sides will be floor slabs. There is usually a wall on the third side.
Vertical supports are brought under the holding elements of the bottom, which are the bars. They must be fixed so that the bottom of the formwork does not slide off the vertical supports, which are load-bearing. For this, a univilka is used, although not always. As a rule, during the construction of a private house, there is no special supporting equipment, therefore, the fixing of parts of the formwork can be done using nails or staples.
An important point in this process is the support of the formwork in the floor plane, which should be as strong as possible. This can be achieved by compacting the soil and backing with some kind of board or tile material.

After the formwork is ready, and there is no doubt about its strength, we proceed to the next stage.

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Making a reinforcement grid

Regardless of the size of the site, it must be reinforced between the floor slabs.

For slab spacing from 1.5 m, in addition to reinforcing bars, it is best to use reinforced mesh... If the distance is small, you can limit yourself to two layers of a lattice of rods.

Reinforcement mesh forming process:

The reinforcement grid is laid 5 cm above the bottom of the formwork, the reinforcement is pulled together with wire.

The rods must be sawn off of a certain length, taking into account the step, which should be about 15-20 cm. Further, the prepared rods are tied together with a wire. As a result, you should get two layers of the lattice.
When installing the first layer, the reinforcement grid must be laid 5 cm above the bottom of the formwork, for which the "glasses" are intended. After that, laying the mesh on top, lay the second layer of the lattice.
If the area between the floor slabs is not so large, the reinforcement can be made with rods without mesh. In this case, the frame is formed in two layers, each of them must be 5 cm away from the edge of the plate.It is worth noting that it is not necessary to use a welding machine in this process, since all connections can be made using a metal wire.

Some people advise inserting reinforcing bars into the holes pre-drilled in the slabs, but this is not worth doing. The monolith section will be supported by the recesses that are present on any floor slab models. They can be either longitudinal or round, resembling a glass.

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Production and pouring of concrete

Table of proportions of components for the manufacture of concrete.

Before you start kneading concrete mortar, you need to prepare all the necessary components. Since the monolithic area looks like a rectangular parallelepiped, then calculate required amount solution in cubic meters it won't be that hard.

After all the components are prepared, you can proceed to the preparation of the solution in a concrete mixer, observing certain rules:

adhere to the loading rate;
the concrete mixer must be installed on a perfectly horizontal surface;
the solution needs to be unloaded into a special container, and after that - to the required place.

As for the last rule, it can only be violated if the concrete mixer is installed next to the formwork, and the prepared solution is discharged directly into it. Refilling should be carried out no later than 2-3 hours. You can make one fill, this is important if the area is not wide. After that, the surface must be leveled, for which a trowel or rule is used.

Even in professional schemes floor layouts are often found in a monolithic area between slabs in buildings of complex configuration. Concreting this piece is much easier than casting a solid slab, since the lower, upper level is set by default, there is no side formwork, the lower shield is enough. One option is to use prefabricated monolithic floor SMP.

Monolithic slab technology

In individual construction, slabs are more often used. standard height 220 mm. This must be taken into account when reinforcing self-made plot, providing the minimum possible protective layer of 15 - 30 mm. If the monolithic section between the floors will protrude above the adjacent ones, an increase in the thickness of the screed will be required when finishing the floors.

Factory floors have voids in which it is convenient to stretch the electrical cable. In a homemade slab, communications must be bricked up before pouring, so as not to chisel the concrete later. This technique is often used for the manufacture of hatches. If stair openings are cut in slabs made industrially, the reinforcement scheme is violated, the structure loses bearing capacity, becomes dangerous for operation.

Formwork

The monolithic section between the slabs is poured onto the shield, which must be supported from below with racks. The simplest calculations of sawn timber cross-sections are the most a budget option for an individual builder, show that boards, timber with minimum dimensions can be used for formwork:

In this case, the structure will withstand the weight concrete floor without sagging, changing geometry.

By default, the monolithic section between the slabs has a side formwork, which are the ends of reinforced concrete products laid in place. It remains to place under the bottom surface of the board, bringing their edges under the existing PC plates, to check the flatness, the absence of deflection in any direction. To do this, you need to follow the steps:

After that, between the extreme pillars, the remaining pillars are mounted, ensuring the horizontalness of the beams, girders, deck boards. When choosing wood of grade 2, the bending strength of the lumber is insufficient. except bottom strapping pillars with boards of 25 mm, necessary to prevent shear during pouring, a similar strapping is additionally used at the level of 1.3 - 1.5 m. All pillars are sewn "inch" across, lengthwise, forming a rigid spatial structure.

Stackable racks are used to facilitate demoulding:

they are made less than the design height
build up in pieces in the upper part, which is enough to unscrew during dismantling

When stripping, first dismantle the lower bars of the racks, then remove the beams with the upper pieces of the racks. After that, the deck is dismantled with the girders screwed to it. In the future, all lumber is suitable for construction rafter system... If you choose grade I wood, you can reduce the costs of the "inch" board for strapping the posts in the middle part.

If it is necessary to fix the formwork elements to the existing walls, it is better to use anchors with metal sleeves. They are easily removed from the masonry after stripping, in contrast to the dowel-nails, the plastic elements of which are almost impossible to remove from the wall.

Deck

At this stage, the monolithic section between the slabs is equipped with a deck on top of the purlins. The edges of the boards are brought under the existing floor slabs, the middle lies on the beams, which ensures the rigidity of the structure.

The gaps between the boards are foamed from the inside of the formwork (from above), the boards are covered plastic wrap... This will keep water in the concrete, facilitate demoulding, and prevent cracking of the floor slab. Plank construction is convenient for wiring engineering systems- holes of any diameter are drilled with crowns, drills without any problems in any area.

When the width of the hollow section is less than 1 m, the technology without posts, beams is often used:

The deck is attracted by wire twists through the timber to the lower planes of the laid slabs, reinforced, poured along standard technology... It is not recommended to punch holes for reinforcement at the ends of the slabs, as they weaken the structure of hollow PC products. Wire clamps cut off angle grinders when stripping flush, part remains inside a monolithic piece.

To increase the overlap resource, reinforcement of at least A-III of periodic section (hot-rolled) with a diameter of 10 - 16 mm is used. The main nuances of reinforcement are:

For knitting the joints of the cells, a wire of 1 - 2 mm is used, the knots are created by manual, mechanical hooks, homemade rig installed in a screwdriver or with a special knitting gun.

The area between the slabs can be reinforced with a ready-made mesh or a mesh connected at the site of operation. In the first case, the dimensions of the longitudinal are removed, cross bars taking into account 4 cm of protective layer on each side. The nets are knitted on flat areas, laid on the deck on top of the film on spacers 15 - 30 mm. Most often, concrete bars 10 x 10 cm are used or plastic supports with cross-shaped slots for reinforcement.

For the top layer, these devices are not suitable due to their small size. Clamps, staples, tables are used here different forms, designs. The main task of these elements is to support the upper mesh in the design position (15 - 30 mm below the slab plane).

For bending reinforcement, apply homemade gadgets... For example, a piece of 50 - 70 cm of pipe with a 10 - 15 cm mandrel welded to one of its edges will provide the required radius (5 bar diameters) and reduce the force.

The area between the slabs may contain nodes for the input of engineering systems. Embedded, void formers are installed after or before reinforcement, depending on the location, configuration, size. For example, it is better to mount an 11 cm sewer cross before laying the nets, sleeves for water pipes can be installed at any stage.

Void formers complex shape required for specific communications. Therefore, they are usually made from polystyrene foam, expanded polystyrene, cutting into pieces of the same format to achieve the desired length from a 5 cm sheet.

For rigid fixation, absence of movement of light polymer fittings, expanded polystyrene holders when pouring the floor, the following technology is used:

plugs are put on the fitting
fixed with self-tapping screws from below through the deck
or the plug is screwed with screws from above
then a fitting is put on it

Internal staircases can rely on these areas, which are poured on their own. For them it is necessary:

release bottom mesh reinforcement
to make a step for supporting the reinforced concrete structure of the march with a reciprocal seat
install the formwork for the staircase / hatch

To release the reinforcement, you will need to make cuts in wooden board jumpers with a chain saw. Put the board on the reinforcement, passing it through the cuts, foaming the remaining slots. Steps, recesses are created by screwing narrow strips to the formwork from the inside.

Fill

Before placing concrete between floor slabs, it is recommended to prime the ends of existing slabs to increase adhesion. The main recommendations for concrete work are:

Solar ultraviolet light, hot dry weather, frost are contraindicated for concrete. Covering with burlap, sawdust, sand allows the surface to be wetted without destruction. The film protects against sun rays, in winter it provides the principle of a thermos, keeping the heat that forms during the hydration of cement with water.

The concrete grade is selected in accordance with the standards of SP 63.13330 for reinforced concrete structures:

density - 1 800 - 2 500 kg / m 3
compressive strength - from B7.5

Water tightness, frost resistance for structures operated indoors does not matter much. At self-production concrete, it is necessary to take into account that the probability of cracking is sharply reduced if filler of various fractions with a continuous row of grains is used. The sand should not exceed 1/3 of the total volume of the aggregate.

After pouring between the floor slabs, sagging may remain in the newly made section. They are polished with a diamond tool for angle grinders ("grinder") of the disc type. If the project includes a self-leveling, warm floor, screed, alignment of the joints is not necessary. For better adhesion of two adjacent reinforced concrete structures, grooves can be made in the lateral edges of the factory plates if the appropriate tool is available.

When placing concrete, these recesses are filled with a mixture, two slabs are obtained almost monolithic. The quality of the lower edge of the slab is usually inferior to factory counterparts, therefore, finishing with stretch, level ceilings is often used.

This technology is very convenient in the manufacture of hatches or stairways... These technological holes can be reinforced with rods diagonally located near them, dramatically increasing the strength of reinforced concrete. Cutting a hatch into a factory slab compromises the integrity of the mesh reinforcement, weakening the default design. This is especially true when the opening is displaced in the middle of the slab.

The technology of a self-made monolithic overlap section allows you to fill the voids when laying out the slabs without reducing the structural strength. Even without pre-tensioning of the reinforcement, the slabs have a high resource if the specified requirements are met.

Any building, regardless of the number of storeys, has floors. They can be wooden or concrete. The most reliable is a monolithic floor slab. Consider its advantages and construction rules.

Types of plates, schemes
Self-styling technology
Price

Types and features of the device

The most popular overlap today, both in cottage and in industrial construction, is, of course, a monolithic slab.

Those who have the opportunity to order construction equipment (crane) prefer ready-made reinforced concrete products (quickly and fairly cheaply). Many people cast the monolith themselves, creating a system of removable or non-removable formwork.

Prefabricated monolithic floors (Marko, TERIVA, ChPP, YTONG) are also very convenient and available.

Since the monolithic floor slab is one of the load-bearing structures, then for their manufacture concrete of heavy grades, lightweight structural concrete of dense structure, as well as dense silicate concrete can be used.

To install a monolithic overlap, it is worthwhile to determine its type in advance, since they differ in technical parameters, and for the price.

The advantages of floor slabs and their types

According to the structure, the panels are solid and hollow, and according to the method of installation, prefabricated, prefabricated monolithic and monolithic. All of them fall under the concept of monolithic floors, at the finishing stage all layers are monolithic. Such structures have not only high strength rates, but also fire safety, moisture resistance and are extremely durable.

Prefabricated slabs made of reinforced concrete panels

Most often they are made of hollow-core panels, which are distinguished by an acceptable price, lower weight, increased thermal insulation properties compared to monolithic ones. Ceilings from them are quickly mounted, and a wide range of sizes allows you to choose a slab according to the needs of the customer. The only drawback is the mandatory use of a crane.

The length of the slabs produced is from 1.8 to 15 meters, the width is from 0.6 to 2.4 m.

The standard thickness of factory PCs is 220 mm, and the calculated bearing capacity (from 350 to 800 kgf / m2) of the panels differs due to the use of different brands concrete and reinforcement. The weight of the slabs depends on the size and ranges from 0.65 to 2.5 tons.

Marking allows you to define the required parameters. Letters designate the type of product PC (floor panel), PNO (lightweight flooring panel), numbers - length and width in decimeters, as well as the load in kilopascals. By removing the self-weight of the slab from the design load, the permissible payload is obtained. When laying parts on a wall, the depth of support must be maintained at least 12 cm.

If the length of the room to be covered is more than 9 meters, a monolithic ribbed slab will do. It is twice as light (weight per square meter is about 270 kg), which reduces by almost a quarter total load on the walls.

Sometimes cracks are found in the floor slabs. They are shrinkage or deformation. Cracks up to 0.3 mm are not dangerous, but if the panel has large diagonal or longitudinal cracks, it is better to replace it. If cracks appear during operation, then it is necessary to reinforce the slab by building on top of an additional reinforced screed layer.

For insulating the ends of the panels in outside wall, which serve as "bridges of cold", use lightweight concrete thermal liners.

Practice shows that sometimes the dimensions of the room turn out to be disproportionate to the width of the panels and it becomes necessary to additionally fill in monolithic areas between the plates. If the slabs move up to 5 cm, such seams are poured with concrete without reinforcement; seams over this size require the installation of an additional reinforcement cage.

Before laying the floor on load-bearing walls be sure to arrange a reinforced monolithic belt under the slabs. This is a continuous closed beam, the reinforcement of which is carried out with high-quality rolled metal.

In order to guarantee the purchase of high-quality reinforced concrete PCs, it is better to buy them directly from reinforced concrete factories or from construction companies that have the capacity for the production of reinforced concrete products.

The average price of one square meter of a hollow-core floor panel in Moscow and the region ranges from 1,100 to 1,200 rubles. The most popular slabs are from 3 to 7 meters, while products of shorter and longer length will cost more (in terms of m2). The most popular width is 1.2 - 1.5 m.

Slabs up to 1 meter wide and 1.8 meters wide are not produced by all manufacturers, which also affects their price.

Prefabricated monolithic

Device precast-monolithic floors has not yet become the most popular method, but has already conquered its niche in construction market... The essence of the method: reinforced concrete beams are laid on the walls (step - 60 cm) and between them are hollow blocks, the whole structure is monolithic.

Installation is possible without the use of mechanisms, since the weight of a running meter of a beam is 19 kg. Due to the large-hollow blocks, it is lightweight and has increased thermal insulation qualities. The only drawback is labor intensity (blocks are stacked manually).

Before pouring concrete, the structure should be reinforced (wire mesh with 10x10 cm cells), minimum thickness a layer of concrete at least 5 cm.

One square meter the finished floor weighs up to 390 kg (if the blocks are made of expanded clay concrete) and up to 300 kg (if the blocks are made of polystyrene concrete). And this is almost two times less than a monolithic floor with a thickness of 2 cm (about 500 kg / m2).

GSK "Columbus" (MARCO) square meter of structures, which consist of precast monolithic slabs floors, offers an average of 1,100 rubles, and work on a "turnkey" device will cost 3,000 - 3,500 rubles per m2.

Self-assembly

When building a house with your own hands, it is possible to install monolithic interfloor floors in place. After forcing the walls of the first floor, they begin to build the formwork for a monolithic slab. Supports of the same size and height are installed in 1 meter increments around the entire perimeter of the slab. The bars connecting them are close to the walls.

Boards are laid on the supports, roofing material on top (without going to the walls). The formwork is placed along the perimeter of the future slab so that the monolith reliably rests on the walls. The armature is placed at a distance of at least 50 mm from the insulation layer. The calculation of the required footage of the rods is done according to the formula - S (area) x4x2. The most problematic moment is the filling.

To supply concrete to a height, you need to order a concrete pump.

Milling the slab on your own

Comparative Cost Analysis

Comparison of two types will be very indicative: using ready-made hollow-core reinforced concrete slabs and making a monolithic slab with your own hands overlapping 6x6 (conditional dimensions). The slab thickness in both cases is 0.22 m, the bearing load is 8 kPa.

Overlapping with slabs:

You will need 5 plates of PC 62.12 - 8. (costs - 8,000 x 5 = 40,000 rubles)
Delivery and rental of a crane will cost approximately 10,000.
Grouting and anchoring (0.5 m3 of concrete) - 2,000
Installation takes place in one day, two workers are enough (salary).

Total - about 55,000.

DIY monolith:

Expenses for formwork (lumber 2 m3) and fasteners - 8,000.
Reinforcement (steel rod, diameter 10, mesh by calculation + wire for bundling) about 0.6 tons with delivery can be bought for 20,000 rubles
Ready concrete (M300) 8 m3 and renting a concrete pump will cost 26,000 - 29,000
Workers (4 days formwork, reinforcement binding, pouring) - 20,000.
Expenses for Additional materials and tools - 3,000.
The period of technological concrete hardening is 3 days.

The result is about 80,000 rubles and a week of time.

The cost of a square meter of prefabricated flooring is slightly more than 1,500, and of a monolithic one - 2,200.

Source: http://stoneguru.ru/monolitnaya-plita-perekrytiya.html

Monolithic sections between floor slabs

Before you decide to independently make monolithic sections between the floor slabs, soberly assess your capabilities, because this is a serious painstaking work. But if you nevertheless decide to make a monolith between the slabs yourself, then you have to go through the following installation steps.

Monolithic plot diagram.

1 Surface preparation
2 Structural calculations
3 Manufacturing of formwork
4 Formwork installation
5 Installation of prefabricated metal structures

Surface preparation

At this stage, you have to make sure that in the right moment you had the right materials and tools at your fingertips. Therefore, oh, availability must be taken care of in advance.

So, to make a monolithic overlap section, you will need the following tools: a hammer drill, self-tapping screws for wood 90 mm long, standard threaded rods of 2 m each, nuts, washers, open-end and union wrenches, concrete drills, wood drills 90 cm long, screwdriver, cross-shaped bits for a screwdriver of very good quality ( good quality required because the edges of a low-quality cue ball are erased very quickly), a hook, a grinder with discs for metal, a circular saw with diamond dust (for cutting boards along and across the fiber), an 800-gram hammer, a sledgehammer up to 3 kg, steel nails 120 mm in size , tape measure - 2-3 pieces (tape measures are necessary for making accurate measurements, there should be a sufficient number of them, since they often break and get lost), carpenter's pencil, carpenter's corner 50 cm long, joiner's stapler with staples, level.

You will also need building materials: knitting wire with a diameter of 0.3 mm for binding frames, reinforcement with a diameter of 12 mm, wire with a diameter of at least 6 mm, cement, gravel, sand, film 100-120 microns thick, boards 50x150 mm, boards 5x50 mm.

It is also necessary to take care of the means of protection in advance, because you and your assistants will have to work at a high altitude among the nails, fittings and boards sticking out in all directions. For protection, you will need: gloves, closed shoes (construction boots or shoes made of dense fabric such as army ankle boots of the old model), goggles, a cap or helmet.

Structural calculations

Calculation of the prefabricated floor slab.

At this stage, you will need to make accurate measurements and calculations in order to know what and how much you will need. First of all, we find out what the floor slabs will be.

To do this, we find out the width of the building and divide it in half, into two equal parts.

We immediately determine where the stairs to the second floor will be, on which side there will be a rise flight of stairs, and only after that we calculate the size and number of floor slabs.

Floor slab length is the width of the house divided by 2.

The width of the floor slab is three standard sizes: 80 cm, 1 m 20 cm, 1 m 50 cm.

We calculate the required size and number of floor slabs, taking into account the fact that there should be a gap of 7 cm between the slabs. After everything has been calculated and accurately determined the required size and number of floor slabs, we order them from the manufacturer or from suppliers of building materials.

Attention!

Do not forget to take into account the 7 cm gap between the floor slabs! The absence of a gap between the plates will complicate their installation and subsequently may cause deformation.

Formwork manufacturing

Formwork installation scheme.

These boards, called bloopers, are placed along the entire length of the shield every 40-50 cm. Remember: the first and last frogs should be no closer than 10 cm from the edge of the edge of the shield. We fasten the bloopers to the boards with self-tapping screws 90 mm long using a screwdriver at the rate of 3-4 self-tapping screws per 1 stitched board.

Then align the edges of the flap circular saw with the help of a carpentry corner.

You will need 3 such prefabricated panels, they will become the ribs of the formwork.

Formwork installation

Formwork installation scheme.

To complete this stage of work, a team of 3-4 people is required.

To facilitate assembly, we put one shield as a base. We install a spacer under each blooper so that nothing sags under load.

We fasten the ribs to the base of the formwork. We fasten the ribs taking into account how wide we need the beam. Beams of three sizes are allowed: 35, 40, 45 cm.

With the required width of 35 cm, both side ribs are flush. With a required width of 40 cm, only one edge of the two prefabricated panels is flush.

If you need a 45 cm wide beam, the ribs are attached without using this technique. All are fastened with self-tapping screws.

As a result, we got a box of three prefabricated panels in the place where the future beam will be located.

Figure 4. Types of attachment of ribs to the base. A - 35 cm, B - 40 cm, B - 45 cm.

Now we harvest the spacers from the reinforcement. They will be needed in order to withstand right size beams and avoid bevels. We simply cut the reinforcement into pieces of the desired length (35, 40 or 45 cm).

If this is not done, the concrete will lose a lot of moisture along with the sand and cement. After drying, gravel will show up strongly on the outer edges of the beam. The surface of the beam will be all covered with strong roughness and irregularities, bumps and depressions, the so-called shells.

Such a beam will be of poor quality, and it will have to be redone.

Assembly of prefabricated metal structures

Reinforcement cage diagram.

We start knitting the frame on the ground. We make 8 veins of a given length from the reinforcement (the length of one vein is equal to the length of the future beam).

Now we make clamps from M-6 wire, which are bent manually. From a single piece of wire, it is necessary to make a square with a given length of its sides.

So, for a beam of 35x35 cm in size, a clamp with sides of 30 cm is needed, for a beam of 40x40 cm we make a clamp of 35x35 cm, for a beam of 45x45 cm - a clamp of 40x40 cm. ...

Remember: the minimum distance between the wall of the formwork and the clamp should be 2.5-3 cm, not less!

This is necessary so that, as a result, the metal parts of the clamp are not visible on the surface of the beam. If the metal appears on the surface of the beam, then it is in this place that metal corrosion and destruction of concrete, and hence the beam itself, will begin.

The ends of the clamp are overlapped, that is, there should be an overlap of the ends of the clamp, which are fastened to each other with a double knitting wire with a diameter of 0.3 mm.

The wire is folded in half to form a double knitting wire. It is with such a wire that the ends of the clamp should be tied.

Knowing that the clamps should be located along the entire length of the beam at a distance of 40-50 cm from each other, it is easy to calculate the required number.

Putting the frame together. To do this, we tie to each side of the clamp with a double knitting wire, 2 cores at an equal distance from the folds and between each other. Place the clamps on the veins 40-50 cm apart. The distance between the clamps must be maintained without fail.

We put the finished frame in mounted box being careful not to damage the film. If suddenly the film is damaged, then it's okay, just close the hole with another piece of film and secure it with a stapler.

Sometimes, for various reasons, you have to make veins from pieces of reinforcement different lengths... There is nothing wrong with that, the construction technology allows it.

Simply take another piece of reinforcement and overlap it with a double knitting wire over the junction of the two pieces of vein, making sure that the overlap is 60 cm on each side. This immediately explains why builders prefer to make veins from solid pieces of rebar rather than assemble them from pieces.

After all, if you collect from pieces of different lengths, you get a strong overrun building material... Moreover, this work is carried out when the frame is already inside the box.

Diy monolithic flooring scheme.

Then we take a drill for wood and, taking into account the fact that the concrete pressure comes from below, we make holes equal to the diameter of the stud, 15-20 cm from the bottom of the box. We make 1 through hole at the bottom of each blooper. We cut the studs to the length we need.

The length is calculated as follows: the width of the support beam + two thicknesses of the board + two thicknesses of the blooper + two reserves of thread for tightening nuts with washers. We insert the resulting pins into the box.

Now we take pre-prepared pieces of reinforcement - spacers. We install them on top of each stud. We twist the studs to the light stop of the spacers so that they hold.

We take a level and level the formwork vertically to the ground so that it does not lead after compression. All deviations in one direction or another are eliminated using side struts. The installation of studs and the installation of spacers is one of the important prefabricated stages of the design.

After installing the spacers, check everything again with a level, only then attach all the support boards to the formwork with nails or self-tapping screws.

Now we start hanging the frame. To hang the frame, it must be tied to the studs. The easiest way to do this is using a height template - a small board measuring 2.5x2.5x30 cm. It's simple: place a height template under each clamp and tie it to the hairpin where it touches with a double knitting wire. After fixing the last clamp, the frame will be suspended in the air.

After that, check and inspect everything. Do not allow film breaks or clamps to touch the box walls. Then we fill in the transverse slats for sewing together the formwork boards. From the bottom of the base, we measure the height of the beam and drive in nails along the entire length of the box at this height. These nails are beacons, concrete will be poured over them.

Now we check the strength of the bottom and side struts, they should freely withstand a decent weight. If in doubt, add more props. Remember: concrete has a high density. The slightest mistake - and the structure will collapse under the weight of concrete.

We made sure that everything was done correctly - then feel free to pour concrete.

For the manufacture of beams, cement of the M300 or M350 brand is used, which is best bought ready-made, since the beam must be poured at one time without interruption. If this is not possible, hire a large concrete mixer to mix the entire required volume of concrete in one go.

After 3-5 days, in good weather, the concrete will dry out; in bad weather, it will take longer.

After the concrete has completely dried, you can start dismantling wooden formwork and the installation of the floor slabs themselves.

Monolithic sections between floor slabs

Monolithic plot diagram.

Surface preparation

At this stage, you have to make sure that at the right time you have the right materials and tools at hand. Therefore, oh, availability must be taken care of in advance.

So, to make a monolithic overlap section, you will need the following tools: a hammer drill, self-tapping screws for wood 90 mm long, standard threaded rods of 2 m each, nuts, washers, open-end and union wrenches, concrete drills, wood drills 90 cm long, screwdriver. cross-shaped cues for a screwdriver of very good quality (good quality is required because the edges of low-quality cue balls are erased very quickly), a hook, a grinder with discs for metal, a circular saw with diamond dust (for cutting boards along and across the fiber), an 800-gram hammer, sledgehammer up to 3 kg, steel nails 120 mm in size, tape measure # 8211 2-3 pieces (tape measures are necessary for making accurate measurements, there should be a sufficient number of them, as they often break and get lost), carpenter's pencil, carpenter's corner 50 cm long, joinery stapler with staples, level.

Structural calculations

Calculation of the prefabricated floor slab.

At this stage, you will need to make accurate measurements and calculations in order to know what and how much you need. First of all, we find out what the floor slabs will be. To do this, we find out the width of the building and divide it in half, into two equal parts. We immediately determine where the stairs to the second floor will be, on which side the staircase will rise, and only after that we calculate the size and number of floor slabs.

The length of Floor Slab # 8211 is the width of the house divided by 2.

The width of the floor slab comes in three standard sizes: 80 cm, 1 m 20 cm, 1 m 50 cm.

Do not forget to take into account the 7 cm gap between the floor slabs! The absence of a gap between the plates will complicate their installation and subsequently may cause deformation.

Monolithic section between two slabs 980 mm wide (download drawing in dwg format)

Sometimes it is necessary to make wide monolithic sections between the floor slabs. They must be calculated according to the current loads. The drawing shows a monolithic section 980 mm wide, supported by two hollow core slabs... The conditions for such a monolithic section (loads, principles of reinforcement, etc.) are detailed in the article Monolithic section between two prefabricated slabs.

Monolithic section between two prefabricated slabs

Such a monolithic section acts as a slab resting on adjacent prefabricated slabs. To do this, it has a working reinforcement curved with a trough, the diameter of which depends on the width of the section (the estimated length of the slab of this section) and the load on the floor. Longitudinal reinforcement is structural, it creates a reinforcing mesh, but does not bear any load. On the top of the wide monolithic section, an anti-shrink mesh made of smooth reinforcement of small diameter is also laid.

The figure shows examples of reinforcement of two monolithic areas in housing (without any additional loads in the form of warm floors and brick partitions).

As you can see, plots are different widths, but when setting the goal of making a wide monolithic section based on the slabs, you should always check whether the floor slabs will withstand it. This is the most important point in the design of monolithic sections. The load-bearing capacity of floor slabs is different (from 400 to 800 kg / m 2 - excluding the weight of the slab).

Let's say we have two prefabricated slabs with a width of 1.2 m, between which there is a monolithic section with a width of 0.98 m. The bearing capacity of the slabs is 400 kg / m 2. one running meter such a plate can withstand 1.2 * 400 = 480 kg / m.

Let's calculate the load per 1 running meter of the slab from a monolithic section with a thickness of 220 + 30 = 250 mm = 0.25 m. The weight of reinforced concrete is 2500 kg / m 3. The load safety factor is 1.1.

0.25 * 1.1 * 2500 * 0.98 / 2 = 337 kg / m.

We divided by two, because the monolithic section rests on two slabs, and each of them carries half the load.

In addition to the weight of the monolithic area, we have a load on the slabs from the floor structure (140 kg / m 2), from partitions (50 kg / m 2) and a live load from the weight of people, furniture, etc. (150 kg / m 2). Multiplying all this by the coefficients and the width of the precast plate, and adding the load from the monolithic section, we get the final load on each precast plate:

1.3 * 140 * 1.2 / 2 + 1.1 * 50 * 1.2 / 2 + 1.3 * 150 * 1.2 / 2 + 337 = 596 kg / m 480 kg / m.

We see that the load is greater than the plate can withstand. But if you take a slab with a bearing capacity of 600 kg / m 2. then one running meter of such a slab can withstand 1.2 * 600 = 720 kg / m - the reliability of the structure will be ensured.

Thus, it is always necessary to check the bearing capacity of the slabs depending on the dimensions of the monolithic area, the width of the slab and the loads acting on it.

Monolithic slab with an oblique corner. Reinforcing frame for beveled slabs. Concrete work for a monolithic bevel slab. Concrete curing and maintenance.

Reinforcement work SNiP 3.03.01-87 Supporting and enclosing structures, GOST 19292-73... Welding instructions for fittings and embedded parts reinforced concrete structures SN 393-78... Reinforcement production manuals. And other acting regulatory documents.

Concrete works should be carried out in accordance with the requirements and recommendations SNiP 3.03.01-87 Bearing and enclosing structures.

Concrete mix composition... preparation, acceptance rules, control methods and transportation must comply with GOST 7473-85 .

When carrying out construction work reinforced concrete monolithic structures should be guided by the requirements SNiP 3.03.01-87 Supporting and fencing structures and the relevant sections of the safety rules given in SNiP III-4-80... working drawings and instructions of the PPR - the project for the production of work.

1. Monolithic overlap section with oblique angle (UM-1).

In houses... where the construction plan is foreseen with corner transition of walls at an angle not 90 °, as usual, but, for example, 45 ° - overlap are carried out in monolithic version .

You can, of course, take an ordinary reinforced concrete slab and jackhammer knock out the desired bevel of the slab, and cut the reinforcement.

But this is fraught with the fact that if a reinforced concrete slab is made with a stressed reinforcing cage (and this is most often done in reinforced concrete factories - such a cage requires less reinforcement consumption), then in such a truncated form the slab will lose its bearing capacity... Or maybe right away burst during such a circumcision.

NOTE: Tense reinforcement cage is a frame whose rods clamped in a special shape... and then, heating, pulled to the desired size.

Further it welded with transverse frames... poured with concrete and dried in a steaming chamber. Trimming bars from the fixed form was carried out already when the plate was ready-made... Those. reinforcing bars in concrete taut like guitar strings... Well, if the string breaks, you yourself know what happens.

So everyone which does not fit into standard sizes industrial reinforced concrete products and designs, performed in monolithic version at the construction site of the house. In our version monolithic slab is an continuation of national teams reinforced concrete slabs .

2. Reinforcing frame for beveled slab (UM-1).

Manufacturing reinforcement cage and mesh must be carried out according to the drawings and have an exact location welded elements. Replacement envisaged by the project reinforcing steel by class, brand and assortment agreed with a design organization.

Technological manufacturing process reinforcement cage provides for:

straightening and cutting steel fittings, wires... supplied in coils with a diameter 3 ... 14 mm and in bars diameter 12 ... 40 mm on rods of measured length
edit(flexible) and butt welding rods to the desired size
welding meshes and frames
enlarging assembly(welding and wire tying) volumetric reinforcement blocks
transportation and installation frameworks at a construction site.

Reinforcing frame of a monolithic section UM-1 performed according to the dimensions indicated in the diagram (see fig.). And it consists of mesh C-2 and two reinforcement cages K-1. interconnected reinforcement rods from the same steel A-III .

Reinforcement mesh necessary to cook spot welding . For frame and mesh used by fittings according to the indicated table 1.

Table 1: Specification of reinforcement for the framework of a monolithic floor slab.

Creating a monolithic section between the slabs with your own hands

- Installation of supports and formwork
- Reinforcement mesh formation
- Concrete mix and its pouring
- Final recommendations

Construction of a private house # 8211 is a complex and time-consuming task, within the framework of which it is necessary to complete various types works. For example, it may be necessary to fill in a monolithic area between floors due to the fact that it is not possible to form a floor completely from slabs according to the project. This happens very often in cases of the formation of flights of stairs or when it is necessary to lay various communication elements between the plates. It is quite possible to form a monolithic section between the slabs with your own hands. Although this work is laborious, it is quite doable if you adhere to all building codes and regulations.

If you need to lay various communication elements between the plates, you can form a monolithic section between the plates with your own hands.

In the process of forming a section of a monolith between floor slabs, it is important to correctly perform the following work:

install props and form the formwork
to form reinforcing mesh
to cook concrete mix
pour concrete correctly.

Correct performance of these types of work will allow you to create a solid and reliable section of the monolith between the floor slabs in the required place.

Required materials and tools

Considering that the work on the construction of the concrete overlap section consists of different stages, a number of materials must be prepared for each of them. The list of such materials may vary due to different factors, including the distance between the plates to be poured. The standard list looks like this:

On wooden beams the horizontal formwork support is laid.

plywood or boards for creating a direct surface for pouring mortar and side formwork, construction film
wooden beams or metal channels to create a horizontal support on which plywood or a wooden pallet will be laid
timber (120-150 mm), wooden beams or channels to create load-bearing supports for the formwork platform
reinforcing bars (15-25 mm), wire for binding, metal chairs for installing reinforcing bars at the required height (reinforced mesh can also be used)
cement M400, sand, crushed stone, water for mixing concrete mortar
concrete mixer
circular for cutting beams, boards, plywood, as well as metal reinforcing bars
a shovel, a bayonet tool, a trowel or a rule for leveling the surface of the overlap area between the slabs, a protective film to cover this area.

The amount of all materials depends directly on the distance between concrete slabs you need to overlap and how much area as a whole is occupied by a monolithic overlap area. Usually, in private houses, such an overlap area is not very large, so its formation is not too difficult a task. However, in this case, all the same, you should adhere to a clear phasing and rules for working with building materials and structures.

Stages of work on the formation of a monolithic section between floor slabs

A monolithic overlap area between slabs is formed in approximately the same way as any monolithic overlap. Given the small area of such a site, the work, of course, is simplified, but it is necessary to adhere to all building codes and regulations. Therefore, no matter what distance between concrete slabs is poured, all stages of work must be carried out carefully, on which the reliability of the monolithic structure created independently will depend.

Monolithic plot diagram.

At this stage, you have to make sure that at the right time you have the right materials and tools at hand. Therefore, oh, availability must be taken care of in advance.

So, to make a monolithic overlap section, you will need the following tools: a hammer drill, self-tapping screws for wood 90 mm long, standard threaded rods of 2 m each, nuts, washers, open-end and union wrenches, concrete drills, wood drills 90 cm long, screwdriver, cross-shaped cues for a screwdriver of very good quality (good quality is required because the edges of low-quality cue balls are erased very quickly), a hook, a grinder with discs for metal, a circular saw with diamond dust (for cutting boards along and across the fiber), hammer 800- gram, sledgehammer up to 3 kg, steel nails 120 mm in size, tape measure - 2-3 pieces (tape measures are necessary for making accurate measurements, there should be a sufficient number of them, since they often break and get lost), carpenter's pencil, carpenter's corner 50 cm long , joiner's stapler with staples, level.

Structural calculations

Calculation of the prefabricated floor slab.

Floor slab length is the width of the house divided by 2.

The width of the floor slab comes in three standard sizes: 80 cm, 1 m 20 cm, 1 m 50 cm.

Attention!

Do not forget to take into account the 7 cm gap between the floor slabs! The absence of a gap between the plates will complicate their installation and subsequently may cause deformation.

Formwork manufacturing

Formwork installation scheme.

For the manufacture of formwork, we take boards of 50x150 mm and sew a shield 40 cm high from them. 3 boards will go to one shield (1 edge of the future formwork). You will get an edge with a height of 45 cm, where 40 cm is the height of the future floor beam and 5 cm is the required margin. They are sewn with transverse pieces of boards 5x50 mm and 40 cm long. These boards, called blazers, are located along the entire length of the shield every 40-50 cm.Remember: the first and last blinders should be no closer than 10 cm from the edge of the edge of the shield. We fasten the bloopers to the boards with self-tapping screws 90 mm long using a screwdriver at the rate of 3-4 self-tapping screws per 1 stitched board. Then we align the edges of the shield with a circular saw using a carpentry corner.

You will need 3 such prefabricated panels, they will become the ribs of the formwork.

Formwork installation

Formwork installation scheme.

To complete this stage of work, a team of 3-4 people is required.

To facilitate assembly, we put one shield as a base. We install a spacer under each blooper so that nothing sags under load.

We fasten the ribs to the base of the formwork. We fasten the ribs taking into account how wide we need the beam. Beams of three sizes are allowed: 35, 40, 45 cm. With the required width of 35 cm, both side ribs are flush. With a required width of 40 cm, only one edge of the two prefabricated panels is flush. If you need a 45 cm wide beam, the ribs are attached without using this technique. All are fastened with self-tapping screws.

As a result, we got a box of three prefabricated panels in the place where the future beam will be located.

Figure 4. Types of attachment of ribs to the base. A - 35 cm, B - 40 cm, B - 45 cm.

Now we harvest the spacers from the reinforcement. They will be needed in order to withstand the desired size of the beam and prevent bevels. We simply cut the reinforcement into pieces of the desired length (35, 40 or 45 cm).

After that, we proceed to upholstery the resulting box with a film from the inside, while using a joiner's stapler with staples. This is necessary in order to prevent unnecessary loss of water from the concrete and to avoid the appearance of shells. If this is not done, the concrete will lose a lot of moisture along with the sand and cement. After drying, gravel will show up strongly on the outer edges of the beam. The surface of the beam will be all covered with strong roughness and irregularities, bumps and depressions, the so-called shells. Such a beam will be of poor quality, and it will have to be redone.

Assembly of prefabricated metal structures

Reinforcement cage diagram.

We start knitting the frame on the ground. We make 8 veins of a given length from the reinforcement (the length of one vein is equal to the length of the future beam).

Now we make clamps from M-6 wire, which are bent manually. From a single piece of wire, it is necessary to make a square with a given length of its sides. So, for a beam of 35x35 cm in size, a clamp with sides of 30 cm is needed, for a beam of 40x40 cm we make a clamp of 35x35 cm, for a beam of 45x45 cm - a clamp of 40x40 cm. ... Remember: the minimum distance between the wall of the formwork and the clamp should be 2.5-3 cm, not less!

The ends of the clamp are overlapped, that is, there should be an overlap of the ends of the clamp, which are fastened to each other with a double knitting wire with a diameter of 0.3 mm.

The wire is folded in half to form a double knitting wire. It is with such a wire that the ends of the clamp should be tied.

Knowing that the clamps should be located along the entire length of the beam at a distance of 40-50 cm from each other, it is easy to calculate the required number.

We put the finished frame in the installed box, trying not to damage the film. If suddenly the film is damaged, then it's okay, just close the hole with another piece of film and secure it with a stapler.

Sometimes, for various reasons, it is necessary to make veins from pieces of reinforcement of different lengths. There is nothing wrong with that, the construction technology allows it. Simply take another piece of reinforcement and overlap it with a double knitting wire over the junction of the two pieces of vein, making sure that the overlap is 60 cm on each side. This immediately explains why builders prefer to make veins from solid pieces of rebar rather than assemble them from pieces. After all, if you collect from pieces of different lengths, you will get a strong overrun of building material. Moreover, this work is carried out when the frame is already inside the box.

Diy monolithic flooring scheme.

Now we take pre-prepared pieces of reinforcement - spacers. We install them on top of each stud. We twist the studs to the light stop of the spacers so that they hold.

After installing the spacers, check everything again with a level, only then attach all the support boards to the formwork with nails or self-tapping screws.

Now we check the strength of the bottom and side struts, they should freely withstand a decent weight. If in doubt, add more props. Remember: concrete has a high density. The slightest mistake - and the structure will collapse under the weight of concrete.

We made sure that everything was done correctly - then feel free to pour concrete.

After 3-5 days, in good weather, the concrete will dry out; in bad weather, it will take longer.

After the concrete is completely dry, you can start dismantling the wooden formwork and installing the floor slabs themselves.