Hole zones in monolithic overlap. Device staircases. Device of the boardless design for opening in the overlap under the stairs

Depending on the planning of the house, the staircase can be located in a staircase specially designated under it or directly in residential and utility rooms at home. If the staircase is located in the staircase (Fig. 31), then the beams that support the staircases are usually installed after the construction of the walls. For this, the brick walls leave the stroke or wide niches. The ends of wooden beams when installing them in the wall are made with a bevel and turn around with rolled waterproofing materials, for example, a rubberoid or a hot bitumen mastic are labeled. Only side surfaces of the beams are processed by waterproofing, the beamler should be open and not touch the walls! The beam mowing is made for better returns by water vapor, and the waterproofing of side surfaces is to prevent the beams from the walls. Wooden aligning lining can be installed to align the beams in the project mark. They will also prevent the crumpled of wood beams, increasing the area of \u200b\u200btheir painting on the wall. Aligning lining is completely covered with antiseptics, for example, they are pre-bathing in a bitumen primer - a mixture of molten bitumen and diesel fuel. After installing and aligning the beams in the design position, niche (or shoes) are laid by brick and are maintained with a solution. Side waterproofing beam should perform from the plane of the wall, it is better to cut it slightly than to allow the deployment of the end of the beams from the contact of unprotected wood with brick walls.

Fig. 31. Installation of wooden beams in a staircase of bricks or other piece wall materials

If the opening is located in the center of the room, the need arises in fixing the hanging ends of the cropped beams of the frame of the opening with other carriages of overlapping. Cropped wooden beams are fixed with two short paired transverse beams. Cross beams should have a thickness and height equal to the appropriate parameters of the main beams, and are attached to them bolts and coal or special metal profiles. The beams framing the staircase are installed paired, short beams forming the opening are attached to them, and already cut overlapping beams (Fig. 32). On one side of the staircase, it is allowed to cut no more than two beams of overlapping.

Fig. 32. Device of staircase in wooden floors

If the opening is located in the ceiling next to the stone wall, the transverse beams are closed in one end into the wall. The support node of the beam on the brick wall is solved similarly to the node of the design of the platform beam. The landing place is subsequently plastered.

Unlike the opening in the wooden floor, which can be cut into the already finished design, the opening of the reinforced concrete slabs should be left in advance in the process of manufacturing this overlap.

The circuit of the opening is framed by steel profiles: chapellers, heated or design from the corners. To create monolithic areas formed from one or both sides, the contour of the staircase, along the slabs of the overlap placed steel beams, similar to the beams in the wooden overlap. They are based on opposing walls, and between them are inserted into two transverse beams forming the opening (Fig. 33). The fastening of steel beams is performed on welding. The steel frame thus obtained relies on opposite walls as well as all other slabs of overlapping. Inside this frame is left as the staircase, and the reinforced monolithic sections are performed along the edges. The direction of the shelves of longitudinal beam profiles is better to do inside the monolithic plot, it simplifies the manufacture of concrete monolith. The arrangement of shelves of profiles of transverse beams does not matter, but when decorating the opening of the wood, sometimes it is better to direct them inside the staircase.

Fig. 33. Device of staircase in the ceiling of reinforced concrete slabs

The entire steel frame should be lifted by 20-30 mm relative to the bottom plane of the ceiling slabs, then when the monolithic portion of the cement milk will go under profiles and hobs the metal. In order to subsequently, this layer of cement did not fall off and did not expose the steel profile, it is necessary to screw the wire shorter on its lower shelf and make a plaster grid on the beams.

Sometimes, in order to save steel profiles, instead of a design with longitudinal beams from channels from channels or foreign circle, use a wandering scheme. In such a design, longitudinal beams are absent, and the opening is decorated with steel corners, resting with their shelves on the overlap slabs. This design partially transfers the weight of the monolithic area and the stairs to the overlap plates lying alongside. After checking the calculation of the bearing capacity of the slabs of the overlap, this design can be used in small monolithic areas. For a device of wide staircases, it is better not to do it.

The reinforcement of monolithic sites is assigned by the project or by calculation. The lower shield of the formwork is made on Earth and pulls up with ropes to the installation site. Where it is attached to the beams carrying to the formwork. As beams can be used boards installed on the edge or thick reinforcement rods or lomits. Wire hinges are thrown on these beams, insert the fetal wire between the branches and begin to spin the wire. Thus, the formwork shield is attracted and pressed against the slabs lying next to the slabs. In order to avoid the leakage of cement milk, the shield is covered with polyethylene film or pergamine. Reinforcement of monolithic sites and the fill of the concrete mixture. Wire twists remain in the body of concrete forever. When dealing with their ends, protruding from the monolith, cut down or cut into the grinder.

Even in professional layout patterns, the monolithic sections between the plates in the complex configuration buildings are often found. Relieve this piece is much easier than to cast a solid slab, since the lower, the top level is default, there is no side formwork, sufficiently lower shield. One option is to use the collection-monolithic overlap of the SMP.

Technology monolithic overlap

In individual construction, a standard height of 220 mm is used more often. This must be taken into account in the reinforcement of the self-made plot, ensuring the minimum possible protective layer 15 - 30 mm. If the monolithic portion between the ceilings will perform above the adjacent, it will take an increase in the thickness of the screed when the floors are finished.

Factory overlaps have emptiness in which it is convenient to stretch the electrocabylon. In the homemade slab of communication, it is necessary to climb before the fill so as not to lose the concrete later. This technique is often used for the manufacture of hatches. If the stairs for stairs are cut into the plates made by the industrial method, the reinforcement scheme is disturbed, the design loses the carrying ability, becomes dangerous for operation.

Opal

The monolithic plot between the plates is poured onto the shield that must be restored from the bottom with racks. The simplest calculations of sections of sawn timber - the most budget option for an individual developer, show that boards, a ram with minimal dimensions can be used for formwork:

In this case, the design will withstand the weight of concrete overlap without sagging, changes in geometry.

The monolithic portion between the ceiling overlap has a side formwork, which are the ends of the railway products laid in place. It remains to be placed under the bottom surface of the board, starting their edges under the existing PC plates, check the flatness, the lack of a deflection in any direction. To do this, perform actions:

After that, the remaining pillars that ensure the horizontal beams, runs, deck boards are mounted between extreme racks. When choosing wood 2 grades, timber bend strength is insufficient. In addition to the lower strapping of pillars, 25 mm boards, necessary to prevent the shift during the pouring, additionally uses a similar strapping at the level of 1.3 - 1.5 m. All poles are crosslined with an "inches" across, along, forming a rigid spatial design.

To facilitate the platform, the struts are used:

they are made less project height
increased slices at the top, which is enough to unscrew when dismantling

When platforming, the lower bars of racks are first dismantled, then the beams with upper pieces of racks are removed. After that, the deck is dismantled with running to it. In the future, the entire sawn timber is suitable for the construction of a rafter system. If you choose wood I grade, you can reduce the costs of the "inches" board on the strapping of the racks in the middle part.

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

Deck

At this stage, the monolithic plot between the plates is equipped with deck on top of the runs. The edges of the boards are hardened under the existing ceiling plates, the middle lies on the beams, which ensures the stiffness of the structure.

The slots between the boards are removed from the inside of the formwork (from above), the boards are covered with a plastic film. This will save water in concrete, facilitates the platform, will prevent cracking of the ceiling slab. The boarding structure is convenient for wiring engineering systems - holes of any diameter are dried with crowns, drills without problems on any plot.

With a width of a wetting section, less than 1 m is often used without racks, beams:

The deck is attracted by wire twists through the timber to the lower planes of laid stoves, reinforced, poured according to the standard technology. It is not recommended to punch in the ends of the holes for fittings in the ends, as they weaken the design of the hollow products of the PC. Wire clamps are trimmed with an ush with a flush, part remains inside the monolithic piece.

To improve the overlap resource, fittings are used not lower than A-III periodic cross section (hot-rolled) diameter of 10 - 16 mm. The main nuances of reinforcement are:

Wire 1 - 2 mm is used for mating joints of cells, the nodes are created by manual, mechanical hooks, self-made snap, installed in a screwdriver or a special knitting gun.

The plot between the plates can be rejected by a ready-made mesh-related mesh. In the first case, the size of longitudinal, transverse rods, taking into account 4 cm of the protective layer on each side. The grids knit on flat venues, fit on the deck over the film on the gasket 15 - 30 mm. Concrete bars 10 x 10 cm or plastic stands with cruciform slots for fittings are used.

For the top layer, these devices are not suitable due to small sizes. Here are used clamps, brackets, tables of various shapes, structures. The main task of these elements is the support of the upper mesh in the project position (15 to 30 mm below the plane of the plate).

Homemade fixtures are used to bending the reinforcement. For example, a piece of 50 - 70 cm pipe with welded to one edge, a mandrel 10 - 15 cm will provide the required radius (5 diameters of the bar), will reduce the force.

The plot between the plates may contain the entry nodes of engineering systems. Mortgages, hollow-formers are installed after or before reinforcing depending on the location, configuration, size. For example, 11 cm with sewage crosslinor is better to mount up to laying nets, liner sleeves can be installed at any stage.

Difficult forming agents are necessary for specific communications. Therefore, they are usually made of foam, expanded polystyrene, cutting pieces of the same format to achieve the desired length of 5 cm sheet.

For tough fixation, lack of movements of light polymer fittings, polystyrene foam equipment when filling overlap used Technology:

plugs put on fitting
fixed with self-drawing from below through deck
either the plug is screwed with screws from above
then the fitting is put on it

These areas, fill in their own, can rely on the internal staircase marches. For them you need:

release the reinforcement of the bottom grid
make a layout stage Marsham design with retire landing ground
set ladder / hatch formwork

For the release of reinforcement, it will be necessary to make rugs in a wooden shield with a chain saw. To put on the board on the reinforcement, skipping it into the cuts, to fit the remaining gaps. Steps, recesses are created by screwing to the formwork of narrow slats from the inside.

Fill

Before laying concrete between the slabs of the overlap, it is recommended to cubs the ends of the existing plates to increase the adhesion. The main recommendations for concrete works are:

Concrete contraindicated sunny ultraviolet, hot dry weather, frost. Hiding in bags, sawdust, sand allows you to make the surface without destruction. Film in summer protects against sunlight, in winter it provides the principle of the thermos, while maintaining the heat generating cement during hydration.

The brand of concrete is selected in accordance with the provisions of the joint venture 63.13330 for railway structures:

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

Waterproof, frost resistance for designs operated indoors, does not matter much. With independent making of concrete, it is necessary to consider that the probability of cracking is sharply reduced if the filler is used for various fractions with a continuous range of grains. The sand should not exceed 1/3 of the total volume of the aggregate.

After the fill between the slabs of the overlap, the newly made plot can be left. They are grinding with a diamond snap for the USM ("Bulgarian") of a plate type. If the project is laid in bulk, warm floor, screed, butt alignment is not necessary. For better clutch of two adjacent railway structures in the lateral edges of the factory plates can be made in the presence of an appropriate tool.

These excavations when laying concrete are filled with a mixture, two plates are obtained practically monolithic. The quality of the lower edge of the slab is usually inferior to factory counterparts, so it is more common to finish with tension, level ceilings.

Such technology is very convenient in the manufacture of hatches or staircases. These technological holes can be strengthened by diagonally located near them with rods, sharply increase the strength of the reinforced concrete. If you cut the hatch in the factory plate, the integrity of the reinforcement grids is disturbed, which weakens the default design. This is especially true when offseting the opening in the middle of the slab.

The technology of the monolithic portion of the homemade overlap allows you to fill empties when laying the plates without reducing structural strength. Even without prior tension, the plates have a high resource when complying with these requirements.

In brick houses, concrete or concrete blocks, overlappings are usually performed from reinforced concrete. They provide exceptional strength and seismic resistance of the structure, as well as very durable and do not burn, which is important. There are several ways to arrange reinforced concrete floors. The most common and universal - laying of plates of flooding of factory manufacture. Such plates are ordered at the ZhBI factories, and then mounted with the workers' crane and brigade. In the same cases, when the use of lifting crane on the construction site is difficult, or when the house has a non-standard layout and it is difficult to perform the layout of finished plates, the monolithic slab of the overlapping is placed. You can actually fill the monolithic slab not only when there is a testimony for this, but simply because you consider it more appropriate. In this article we will tell you how to lay the slabs of overlapping and how to fill the monolithic plate. Not all work can be performed independently, but it is still worth familiar with the technology, at least in order to control the process at the construction site.

Monolithic slab overlaid with their own hands

The monolithic overlap has a number of advantages compared to overlapping from finished reinforced concrete slabs. First, the design is solid and monolithic without a single seam, which ensures uniform load on the walls and the foundation. Secondly, the monolithic fill allows you to make a layout in the house more free, as it can rely on the columns. Also, the planning can mean how many angles of corners and zakulkov, which would be difficult to choose the slab overlapping the standard sizes. Thirdly, you can safely equip the balcony without an extra composure plate, as the design is monolith.

You can equip the monolithic slab slab on your own, for this you do not need a lifting crane or a large brigade of workers. The main thing is to comply with technology and do not save on materials.

Like everything that concerns construction, the monolithic overlap begins with the project. It is advisable to order the calculation of the monolithic slab overlap in the project office and do not save on it. Usually it includes the calculation of the cross section of the slab to the action of the bending moment at maximum load. As a result, you will get optimal sizes for the slab of the overlap specifically in your home, instructions, which fittings are used and what class of concrete. If you wish to try to perform calculations yourself, then an example of calculating the monolithic slab overlap can be found on the Internet. We will not sharpen attention on this. Consider the option when an ordinary country house is built with a span no more than 7 m, so we will make a monolithic slab overlap of the most popular recommended size: thickness from 180 to 200 mm.

Materials for the manufacture of monolithic slab overlap:

Formwork.
Supports for maintaining formwork at the rate of 1 support per 1 m2.
Steel fittings with a diameter of 10 mm or 12 mm.
Concrete brand M 350 or separate cement, sand and crushed stone.
Bending fixture for reinforcement.
Plastic reinforcement supports (clamps).

Filling technology monolithic floating slabs Includes such steps:

Calculation of the ceiling slabs if the span is more than 7 m, or the project involves the support of the slabs on the column / columns.
Installation of formwork type "Deck".
Plate reinforcement with steel rods.
Pouring concrete.
Concrete seal.

So, after the walls are kicked out at the necessary height, and their level is almost perfectly aligned, you can start the arrangement of the monolithic slab of the overlap.

The device of the monolithic slab overlap assumes that the concrete will be poured into a horizontal formwork. Sometimes the horizontal formwork is also called the "deck". There are several options for its arrangement. First - rent ready removable formwork Metal or plastic. Second - manufacturing on-site formwork using wooden boards or sheets of moisture resistant plywood. Of course, the first option is easier and preferable. First, the formwork is collapsible. Secondly, it offers telescopic supports that are needed to support formwork at the same level.

If you prefer to make a formwork yourself, then consider that the thickness of the plywood sheets should be 20 mm, and the thickness of the edged boards is 25 - 35 mm. If you shoot down the shields from edged boards, they need to be tightly customized to each other. If the slots are visible between the boards, then the surface of the formwork should be causing a waterproofing film.

Installing the formwork is performed in this way:

Vertical support racks are installed. It can be telescopic metal racks whose height can be adjusted. But it is also possible to use wooden logs with a diameter of 8 - 15 cm. The step between the racks should be 1 m. The racks close to the wall should be located at a distance of at least 20 cm from the wall.
On top of the racks, the riglels are stacked (a longitudinal bar, which will hold the formwork, a foreign beam, a chamber service).
The horizontal formwork is stacked on the rigls. If the finished formwork is used, and the lateral beams are stacked on top of the longitudinal bars, on which the sheets of moisture resistant plywood are put on top. The dimensions of the horizontal formwork must be fitted perfectly so that its edges rest in the wall without leaving the gaps.
The height of the pole supports is regulated so that the upper edge of the horizontal formwork coincides with the top edge of the wall masonry.
Vertical formwork elements are installed. Taking into account the fact that the monolithic slab overlap the dimensions should be such that its edges to enter the walls by 150 mm, it is necessary to perform a vertical fence at such a distance from the inside edge of the wall.
The last time is checked horizontal and even arrangement of formwork with levels.

Sometimes for the convenience of further work, the surface of the formwork is covered with a waterproofing film or, if it is made of metal, lubricated with machine oil. In this case, the formwork is easy to remove, and the surface of the concrete slab will be perfectly smooth. The use of telescopic racks for formwork is preferable to wooden supports, as they are reliable, each of them withstands weight up to 2 tons, microcracks are not formed on their surface, as it can happen to a wooden log or bar. Rental of such racks will cost approximately 2.5 - 3 USD. per 1 m2 area.

After the armature framework of two grids is installed after armature formwork. For the manufacture of reinforcement framework, steel reinforcement A-500C with a diameter of 10 - 12 mm is used. From these rods, the grid is associated with a cell size of 200 mm. To connect longitudinal and transverse rods, knitting wire is used 1.2 - 1.5 mm. Most often the length of one reinforcement rod is not enough to cover the whole span, so the rods will have to be interconnected along. In order for the design to be durable, the rods must be connected to the allen in 40 cm.

The reinforcement grid must enter the wall at least 150 mm, if the walls are made of brick, and 250 mm, if the walls are made of aerated concrete. The ends of the rods should not reach the vertical formwork around the perimeter by 25 mm.

Strengthening the monolithic slab overlap is performed using two reinforcement grids. One of them - the lower - should be located at an altitude of 20 - 25 mm from the lower edge of the plate. The second - the upper one should be located 20 - 25 mm below the top edge of the plate.

So that the lower mesh is located on the desired removal, adults are put under it plastic clamps. They are installed in increments of 1 - 1.2 m in the crossing places of rods.

The thickness of the monolithic slab overlap is taken at the rate of 1:30, where 1 is the thickness of the plate, and 30 is the length of the span. For example, if the span is 6 m, then the thickness of the plate will be 200 mm. Considering that the grids should be located on the removal of the plates from the edges, the distance between the grids should be 120-125 mm (from the thickness of the plate 200 mm, we take two gaps of 20 mm and take 4 thickness of reinforcement rods).

To divide the grids for a certain distance from each other, from the reinforcing rod of 10 mm using a special bending tool is made special Locks - Standsas in the photo. The upper and lower shelves of the retainer are 350 mm. The vertical size of the retainer is 120 mm. The installation step of vertical locks 1 m, the ranks should be placed in a checker order.

The next step - end lock. It is installed in a step of 400 mm in the end of the reinforcement frame. It serves to enhance the support of the slab on the wall.

Another important element - top and bottom mesh connector. As he looks, you can see in the photo. It is necessary, so that the spaced grids perceived the load, as one. The installation step of this connector is 400 mm, and in the zone of the wall on the wall, in the range of 700 mm from it, in a step of 200 mm.

Pouring concrete

Concrete is better to order directly at the factory. This greatly facilitates the task. In addition, the pouring of the solution from the mixer with a uniform layer will provide exceptional stove strength. What you can not say about the stove, which was poured by hand with breaks for the preparation of a new portion of the solution. So pour the concrete is better at once with a layer of 200 mm, without breaks. Before pouring concrete to formwork, it is necessary to install a frame or box for technological holes, such as chimney or ventilation channel. After filling it, it is necessary to province the deep vibrator. After that, leave to dry and gain strength on 28 days. The first week the surface must be wedged with water, only moisturize, and not to fill with water. A month later, the formwork can be removed. The monolithic slab overlap is ready. On the installation of slabs of overlapping, the price includes the cost of fittings, concrete, rented formwork and order Mixer Machines, as well as concrete pump. In fact, approximately 50 - 55 cu. per m2 overlaps. How to fill the slab overlapping concrete, you can see in the demonstrating installation of plates of the overlap of video.

How to put overlap plates

The use of monolithic reinforced concrete slabs of factory manufacturer is considered more traditional. PC plates are greater popularity - slabs with round voids. The weight of such plates begins with 1.5 tons, so the laying of the slabs of the overlap is impossible with their own hands. Requires lifting crane. Despite the seeming simplicity of the task, there are a number of nuances and rules that must be observed when working with slabs of overlaps.

Termination Plate Rules

The slab overlap of the factory manufacture has already been reinforced at the factory and does not require additional strengthening or arrangement of formwork. They are simply placed in the span with support on the wall, following some rules:

The span should not be more than 9 m. It is exactly such a plate of the slab is the largest.
Unloading and lifting plates are carried out with the help of special equipment provided by the project. To do this, there are mounting hinges in the stoves, for which the mounting slings gerops are engaged.
Before laying the slabs, the surface of the walls to which they will fit must be aligned. Not allowed large drops of heights and distortions.
Plates must be based on the walls by 90 - 150 mm.
It is impossible to pretend the plates of dry, all the slots and technological seams should be sealed with a solution.
Plate location must be constantly monitored relative to the walls and surfaces of the support.
The plates are stacked only on the bearing walls, all the simpleness are placed only after installing overlaps.
If you want to cut in the overlap of the hatch, then it must be cut on the junction of two plates, and not in one plate.
Plates should be located as close as possible to each other, but with a 03 - 3 cm gap. This will ensure seismic resistance.

If the slabs of the overlap lacks to overlap the entire span, and remains, for example, 500 mm, then there are different ways of laying the slabs of the overlap in that case. The first is to lay the plates in principle, and the gaps leave at the edges of the room, then close the gaps with concrete or slag concrete blocks. The second is laying plates with uniform gaps, which are then close to concrete solution. In order for the solution to not fall down, the formwork is installed under the gap (the board is tested).

Black Plate Styling Technology

In the process of laying slabs, the overlap must be clear coordination between the crane and the brigade, the host. To avoid injuries at the construction site, as well as comply with the entire technological process and the rules described in the bottom, the Project at the construction site should be a technological map of mounting plates of overlapping. It contains a sequence of work, quantity and location of technology, special vehicles and tools.

Start the laying of the slabs of the overlap is necessary from the staircase. After laying the plates, their location is checked. Plates are fit well if:

The difference between the bottom surfaces of the slabs does not exceed 2 mm.
The height difference between the upper surfaces of the slabs does not exceed 4 mm.
The height difference within the site should not exceed 10 mm.

As the installation of the slab is shown, after laying the plate, it is necessary to combine with the walls with metal connecting parts. Works on the connection of mortgages and connecting parts are made welding.

Do not forget that you need to follow safety. It is not allowed to perform work with a lifting crane in an open area with wind 15 m / s, as well as when ice, thunderstorms and fog. During the movement of the slab using a crane, installers should be away from the path by which the stove will move, with the opposite feed feed. Despite the fact that the use of the services of a professional prolage and the installers brigade significantly increase the cost of mounting slabs of the ceiling, yet this is not the case when you can save. The brigadier must provide a project.

Before ordering the plates at the factory, preparatory work must be performed. The time of feeding the car with plates and lifting crane is better to agree at one time not to overpay for simple special equipment. In this case, the installation of the plates can be performed without unloading, directly from the vehicle.

Preparatory work before putting slabs

First - smooth surface of opira. The horizon must be practically ideal, the height difference in 4 - 5 cm is unacceptable. First of all, check the surface of the walls, then, if necessary, align with a concrete solution. Subsequent work can be performed only after concrete acquires maximum strength.

Second - ensure the strength of the support zone. If the walls are erected from bricks, concrete or concrete blocks, then no additional events do not need. If the walls are erected from foam blocks or gas-blocks, then before laying the plates it is necessary to fill armoois. The correct laying of the ceiling slabs assumes that the support surface must be strong enough to withstand the weight of the slab and do not deform along the adjunct line. Neither aerated concrete nor foaminetone has the necessary strength. Therefore, on the entire perimeter of the structure, the formwork is established, the reinforcement frame of a rod 8 is 12 mm, and then everything is poured with a concrete layer 15 - 20 mm. Further work can be continued only after drying the concrete.

Third - install mounting towers. Telescopic supports, as described in the section on the installation of a monolithic slab overlap, are installed in 1.5 m increments. They are called upon to accept the weight of the slab, if suddenly it will slip from their place. After mounting, these tows are cleaned.

Installation of empty slabs of overlapping with a crane

After the fresh concrete adopted sufficient strength and dryness, you can begin directly installing the slabs of the overlap. For this, the lifting crane is used, the load capacity of which depends on the size and weight of the slab, most often the cranes 3 - 7 tons are appreciated.

Stages of work:

A concrete solution of a layer 2 - 3 cm is applied to the support surface. The depth of the solution is equal to the depth of the plates, i.e. 150 mm. If the slab will rely on two opposite walls, then the solution is applied only for two walls. If the slab will rely on three walls, then on the surface of the three walls. Directly laying the plates can begin when the solution will drop 50% of its strength.

While the solution dries out, the craneman can engage the slings for the mounting elements of the plate.
When the crane driver is given a signal that you can feed the stove, the team of workers must move away from the place where the stove moves. When the stove is already quite close, the workers engage her by the battle and unfold, while the oscillatory movements are soaked.

The plate is directed to the right place, one person must stand on one wall, and the other - on the opposite. The stove is stacked so that its edges relied on a wall at least 120 mm, better by 150 mm. After installing the stove, squeeze the excess solution and will evenly distribute the load.

If there is a need to move the slab, you can use scrap. You can only align its location along the laying zone, moving the slab across the walls can not, otherwise the walls can fall. Then the slings are removed, and the signal is served to pick them up.
The procedure is repeated for all plates without exception. The rules for mounting the ceiling slabs suggest that the alignment of the plates should be performed along the lower edge, since it is the lower surface that the ceiling is indoors. Therefore, the stove is stacked with a wider side down, and more narrow - up.

You can meet the recommendation that in the Opporting Zone, the reinforcement is required. Supporters of this method say that it is so convenient and easier to move the stove. In fact, put something except for a concrete solution under the stove is prohibited by a technical card. Otherwise, the stove can be easily moved from the Oppulating Zone, as it will slide along the valve. In addition, the load will be distributed unevenly.

Laying the slabs of overlapping on the foundation is practically no different from laying inter-storey floors. The technology is exactly the same. Only the surface of the foundation must be thoroughly hydroizing before laying the plates. If the project provides non-standard supporting slabs, then for this use special steel elements. Such work should not be done without a specialist.

Anchorovka - binding of plates between themselves - can be performed in two ways depending on the project.

First - binding plates of reinforcement. The reinforcement rods with a diameter of 12 mm are welded to fixing mortgage elements on the stove. At the slabs from different manufacturers, the location of these elements can be different: in the longitudinal end plate or on its surface. The most durable is considered to be diagonally, when the plates are associated with a displacement.

Also, the stove must be associated with the wall. For which fittings make up the wall.

Second way - ring anchor. In fact, he is similar to Armopoyas. On the perimeter of the plate is equipped with a formwork, fittings are installed and concrete is poured. This method somewhat increases the cost of laying the slabs of the overlap. But it is worth it - the plates are sulked from all sides.

After anchoring, you can proceed to the sealing of the slots. The slots between the slabs of the overlap are called Rusta. They are filled with concrete M150 brand. If the slots are large, then the board is tied up, which serves as a formwork. If the slits are small, then the slab overlap can withstand the maximum load already the next day. Otherwise, it is necessary to wait a week.

All modern plates with round voids are made with already filled ends. If you purchased slabs with open holes, then they must be fill in anything by 25 - 30 cm deep. Otherwise, the stove will freeze. You can fill the emptiness with mineral wool, concrete corks, or simply filling with concrete solution. This procedure must be performed not only on those ends that go outside, but also on those rely on the inner walls.

On the laying of the slab overlap the price depends on the volume of work, the area of \u200b\u200bthe house and the value of the materials. For example, the cost of only PC overlapping slabs is approximately 27 - 30 USD. per m2. The rest is the accompanying materials, the rental of crane and hiring workers, as well as the cost of shipping plates. Professional brigades on the installation of slabs of overlapping rates are different from 10 to 25 USD. per m2, maybe more depending on the region. As a result, it turns out the cost is the same as on the pouring of the monolithic slab overlap.

Laying Plates of Overlapping: Video Example

The most reliable (but not always appropriate) a variant of the inter overlook is the monolithic overlap. It is performed from concrete and reinforcement. On the rules of the device of monolithic overlaps, read in this article. The analysis of the characteristics of species and application, devices of monolithic floors.

In what cases it is necessary that the device of monolithic floors

The monolithic reinforced concrete overlap is the most reliable, but also the most expensive of all existing options. Therefore, it is necessary to determine the criteria for the expediency of its device. In what cases is the device of monolithic overlaps appropriate?

The impossibility of delivery / installation of precast concrete slabs. Subject to a conscious refusal of other options (wooden, lightweight terriva, etc.).
Complex configuration in terms of the "unsuccessful" location of the inner walls. It in turn does not allow to decompose a sufficient number of serial plates of overlapping. That is, a large number of monolithic sections is required. The cost of the lifting crane, and on the formwork is not rational. In this case, it is better to immediately move to monolith.
Adverse operating conditions. Very large loads, extremely high moisture values \u200b\u200bthat are not solved completely waterproofing (car wash, swimming pools, etc.). Modern plates of overlappings are usually performed in advance. The steel cables are used as reinforcement. Their cross section in view of very high tensile strength is very small. Such slabs are extremely vulnerable to corrosion processes and are characterized by the brittle, and not plastic nature of destruction.
Combining overlap functions with a monolithic belt function. Opportuning precast concrete slabs directly on masonry from light blocks, as a rule, is not allowed. A monolithic belt is needed. In cases where the cost of the belt and the collection of overlapping is identical or exceeds the price of monolith, it is advisable to stop on it. When describing it on a laying with a depth of a width of the belt, the device of the latter is usually not required. The exception can be complex primer conditions: the sedelion of the 2nd type seismic activity. Clock protection, etc.

Determination of the required thickness of monolithic overlap

For bended slab elements, over the decade, the experience of the use of reinforced concrete structures, the experimental means determined - the ratio of the thickness to the span. For plates of the overlap it is 1/30. That is, with a span 6m, the optimal thickness will be 200mm, for 4.5 mm - 150mm.

Understanding or vice versa, an increase in the resulting thickness may be based on the required loads on the overlap. At low loads (it includes private construction) it is possible to reduce thickness by 10-15%.

VAT overlaps

To determine the general principles of reinforcement of monolithic overlap, it is necessary to understand the typology of its work by analyzing the stress-strain state (VAT). It is most convenient to do this with the help of modern software complexes.

Consider two cases - free (swivel) Opporting plates on the wall, and pinched. The thickness of the plate is 150 mm, the load is 600kg / m2, the size of the plates is 4.5x4.5m.

The deflection is under the same conditions for the pinched plate (left) and the superior hinged (right).

The difference in moments MX.

The difference in moments.

The difference in the selection of the upper reinforcement by H.

The difference in the selection of upper reinforcement in U.

The difference in the selection of lower reinforcement by H.

The difference in the selection of lower reinforcement in U.

The boundary conditions (design character) are modeled with appropriate connections in support nodes (marked in blue). For hinge support, linear movements are prohibited, for pinching - more and turn.

As can be seen from the diagrams, when pincing the work of the pre-site and the middle area of \u200b\u200bthe plate is significantly different. In real life, any reinforced concrete (prefabricated or monolithic) is at least partially pinched in the body of masonry. This nuance is important in determining the nature of the reinforcement of the structure.

Reinforcement of monolithic overlap. Longitudinal and transverse reinforcement

Concrete is perfect for compression. Armature - for stretching. Combining the two of these elements, we get a composite material. Reinforced concrete in which the strengths of each component are involved. It is obvious that the reinforcement should be installed in the stretched zone of concrete and perceive stretching efforts. Such fittings are called longitudinal or working. It should have a good clutch with concrete, otherwise he will not be able to transfer the load on it. For working reinforcement, the rods of the periodic profile are used. They are the A-III (according to the old GOST) or A400 (new).

The distance between the reinforcement rods is a reinforcement step. For overlaps it is usually taken equal to 150 or 200 mm.
In the case of pinching in the prevail zone there is a reference moment. It forms a stretching force in the upper zone. Therefore, the working reinforcement in monolithic floors is located both in the upper and the lower zone of concrete. Special attention should be paid to the lower reinforcement in the center of the plate, and the top of its edges. As well as in the field of supporting internal, intermediate walls / columns, if any - it is here that the greatest voltages arise.

To ensure the required position of the upper reinforcement in concreting, transverse reinforcement is used. It is located vertically. It may be in the form of supporting frames or specially bent parts. In routine slabs, they perform a constructive function. With large loads, transverse reinforcement is involved in the work, preventing decreases (cracking the plates).

In private construction in plates of overlapping, transverse fittings usually performs a purely constructive function. The support transverse force (the "cut") is perceived by concrete. The exception is the presence of point supports - racks (columns). In this case, it will take the calculation of transverse reinforcement in the support zone. Cross fittings, as a rule, is envisaged with a smooth profile. It is indicated by A-I or A240.

To maintain the upper reinforcement during concreting, the curved P-shaped parts were obtained the greatest distribution.

Filling overlap concrete.

Calculation of monolithic overlap Example

Handmade calculation of the required reinforcement is several cumbersome. This is especially true of determining the deflection, taking into account the disclosure of cracks. The norms are allowed in a stretched zone of concrete cracks with rigidly regulated disclosure width. They are not at all noticeable to the eye, we are talking about millimeter. It is easier to simulate several typical situations in the software package that performs the calculations strictly in accordance with the current building standards. How to make the calculation of the device of monolithic overlaps?

The following loads are taken in the settlement:

Own weight of reinforced concrete with a calculated value of 2750kg / m3 (with a regulatory weight 2500kg / m3).
The weight of the floor design is 150 kg / m2.
The weight of partitions (averaged) 150 kg / m2.

General view of the calculation scheme.

Plate deformation scheme under load.

Epur moments mu.

Epur moments MX.

Selection of top reinforcement by H.

Selection of upper reinforcement in U.

Selection of lower reinforcement by x.

Selection of lower reinforcement in U.

The spans were taken equal to 4.5 and 6 m. Longitudinal reinforcement is set:

a-III class fiture,
protective layer 20mm.

Since the area of \u200b\u200bsupporting the plates on the walls was not modeled, the results of the selection of reinforcement in the extreme plates is allowed to ignore. This is a standard nuance of programs that use the finite element method to calculate.

Pay attention to the strict matching of bursts of moments with bursts of the required reinforcement.

Thickness of monolithic overlap

In accordance with the calculations, the calculations can be recommended, for the device of monolithic floors, in private houses the thickness of the overlap of 150mm, for spans up to 4.5 m and 200mm to 6m. Exceed the span to 6m undesirable. The diameter of the reinforcement depends not only on the load and span, but also from the thickness of the plate. Installed often fittings with a diameter of 12mm and step 200mm will form a significant supply. You can usually do 8mm at a step of 150mm or 10mm in increments of 200mm. Even this reinforcement will hardly work at the limit. The payload is accepted at the level of 300kg / m2 - it can form it in the housing, except that, a large closet fully filled with books. The actual load in residential buildings is usually significantly less.

The total required amount of reinforcement is easy to determine based on the averaged weight coefficient of reinforcing 80kg / m3. That is, for the device overlap with an area of \u200b\u200b50m2 with a thickness of 20cm (0.2m) you will need 50 * 0.2 * 80 \u003d 800kg of reinforcement (approximately).

If there are concentrated or more substantial loads and spans, the diameter and pitch of the reinforcement specified in this article are not possible for the monolithic overlap device. You will need to calculate for the corresponding values.

Video: Basic rules of the device of monolithic overlaps

Monolithic overlap