Overlapping is a very important component of any capital building. Their use is closely connected with painting on the walls. Let’s try to figure it out in this topic.
Features and destination
The conversation about the use of overlapping panels is appropriate to start with the fact that when impaired assembly technology, problems are very quickly arising. Periodically report that in different places overlapping. Immediately after that, it is impossible to use the buildings normally.
Plates or overlap panels can rely on the column, or on the outer wall. In any case, they are horizontally.
The purpose of the use of plates is the perception of the load, rendered from above, with partial transfer of it to the vertical carrying structures of the house. In most cases, this is typical products. The advantage of finished plates is:
- comfort to use;
- lack of special requirements when used;
- delay of vapor, gases and water;
- Zero danger of ignition.
In most cases, covering panels are made from reinforced concrete. This is a composite material from purely natural components. Modern products of this kind accordingly, GOST must carry bad weather and severe frost. An important feature of quality blocks is their high mechanical strength. As for the classification of plates, it mainly proceeds from the inner structure and installation methods.
If there are longitudinal cavities in the panel, it can also be used in a residential, and in industrial construction. In the diameter of emptiness in the diameter, such types of products are distinguished:
- with cylindrical channels 159 mm;
- with circular chambers 140 mm (such plates are made of severe concrete species);
- with emptiness 127 mm;
- Round cavities 114 mm.
In order not to fall into unpleasant situations, especially in news releases, you need to pay great attention to the calculation of the main parameters. The values of the ceiling designs are selected for all designs. It takes into account the length of the spans located between the walls. Spatial construction scheme allows you to calculate a massive mass on the supporting structures. Based on this mass, you can determine the loads included on a separate slab.
Important: When calculating the total load, the severity of screed and partitions, insulation materials, furniture and other techniques take into account the severity. Let the stove weighs 2900 kg, and the carrier area is 9 kV. meters. Accordingly, per 1 kV. meter accounts for 322.2 kg of weight. Next, the calculated digit must be taken from the regulatory digit.
From the resulting difference it is necessary to take away an indicative load created by furniture, other structures and household appliances. After that, there must be a solid reserve of safety. Typically, the real load per unit area is 2-3 times less than the value laid in the project. This approach makes it possible to eliminate any surprises in the process of operation.
The greatest static load per point must count with a backup coefficient of 30%.
Dynamic load is calculated already with a backup coefficient of 50%. If you need to evaluate the suitability of old structures, it is necessary to take into account:
- Load features of the walls;
- current state of building blocks;
- Preservation of reinforcement.
Placing in the old apartment heavy furniture products, large cast iron baths, need to take into account the load limit. The most accurate results can be obtained by attracting specialists. Professionally completed calculation will avoid many unpleasant situations. As for the width and height of the slab of the overlap, then there is the more necessary to take into account the recommendations of professionals. In some cases, it is possible to solve the hardening of floor slabs on the spot, using their redeeve on temporary supports.
Cleaning overlap according to the established requirements can be produced only after hardening concrete to 70% of the design value. In this case, they put the only tier of racks. For your information: If you need a platform 50%, you need to put a pair of racks. Spans up to 8 meters long must be constructed with a temporary backup in the center. If the length of the span is more, then the backups need more; but under the plates in short 3 meters support is needed rarely.
Fall and depth according to SNiP
The requirements of SNiP of Russia say that the backbone of the slab overlapping on the underlying wall is determined:
- the purpose of using the building;
- wall width;
- Thread overlapping structures;
- Weighing them;
- seismic hazard level;
- The magnitude of the covered spans.
This is a very difficult problem – and therefore it is necessary to attract engineers to consult. Usually in order to guarantee the reliable operating of the overlap (with amendment for assembly deviations), the greatest nailestone is 12 cm.
Larger nesting in SNIP is simply not provided. PC types panels, PB in brick houses are laying for a couple of short sides. If the design has a length of up to 4 meters, then the nest must be 7 cm; For greater length – it must be 9 cm.
The depth on which the prefabricated structures is based on:
- When the contour is supported – 4 cm;
- When supporting a couple of long and one shortened side – 4 cm;
- In the support of two sides and the plates span up to 4.2 m, the depth should be 5 cm;
- When supporting 2 short and 1 long side – 5 cm;
- With a support for 2 sides with a length of over 4.2 m, the depression depth cannot be less than 7 cm.
SNIP 2.03.01-84 prescribes a number of requirements for anchoring of reinforcement structures set for supports. Of course, this moment also affects the final depth.
Important: The thickness of all parts of the overlap, located above the technical underground premises and passages (drives), is calculated along with the insulation layer.
Separate requirements are presented to the depths of the designs in the grooves. If the overlapping is made with an incorrectly selected overlap, it is possible to fear the appearance of cracks and even complete destruction of structures.
By preparing a supporting node on aerated concrete blocks, it is necessary to take into account all loads created by:
- located above blocks;
- reinforcing belts;
- other subjects, godes on the jumper.
Part of the window jumpers under the overlap simply poured into the U-block. In other cases, the jumper from concrete is cast inside a wooden formwork.
Can be used and felting jumper. The number of blocks that supports the jumper must be rejected by a pair of rods of diameters of 8 mm. The reinforcement band should be 0.9 m on both sides and more.
A row above the jumper from aerated concrete, which is located part of the overlap, should also be strengthened. Otherwise, high point load can hurt much. Attention: jumpers and walls themselves must have the same thickness. Inter-storey flooring plates of overlappings, as well as plates on the walls made from small fuel-concrete blocks, must have a depth of a minimum of 12 cm. Where local loads are transmitted to the laying, it is necessary to shed a solution (no more than 15 cm).
It is strictly not allowed to close the beams and plates of balconies in masonry with pinching. So that the eccentricity is not too large to avoid chipping in the wall of a small aerated concrete, the overlap relies on a row of bricks. They are put “plastics” over the solution or reinforced concrete belt. To self-supporting walls made of aerated concrete plates join brackets.
IMPORTANT: Overlapping from aerated concrete, relying on the base elements must have a lining with waterproofing properties.
The ends of the reinforced concrete floors believe it is to close with reliable insulation. When laying out the brick wall of reinforced concrete carcers, you can choose both flat and ribbed slabs. Do not use technological holes or shock panels. If there is no part of the plate, it is necessary to fill out this disadvantage using the concrete reinforcement grid. When all the plates are laid out, the time of anchoring comes; Immediately close all the seams and looping holes.
If the plates are made on the bearing of the carrier reinforced concrete or on the wall of dense concrete – the depth of the node will be at least 6.5 cm. On the brick wall, this indicator will be 8 cm. But on the cellular concrete, polystyrene and peasilicate – 1 cm and more.
All work must be made as quickly as possible. It is strictly eliminated by the entry of construction garbage in any openings and support nodes.
Minimum maximum limits
Modern technologies allow you to implement almost any constructive solutions. So, with the help of monolithic slab flooring, you can confidently close the span of 6×6 m. Additional points of the support do not need. Such a task is confidently solved:
- a stove leaning on 4 sides (10 cm thick);
- lower mesh 10 mm;
- Upper grid 6 mm.
In most residential buildings built of bricks, the end part of the hollow plate should go on a 9 cm wall. The greatest indicator is 12 cm. Maximum accurate information can be obtained by special calculations. When laying out the slab with emptiness on the panel wall, the minimum limit is 5 cm, and the maximum is 9 cm.
If the wall is made of aerated concrete or foam blocks, these indicators are 12 and 25 cm, respectively.
When using ribbed slabs, all the smallest and largest parameters are preserved the same as for huge products. In both cases, they come from a single-break beam chart. Separate attention deserve parameters of supporting plates for a wooden house. Walls in this case should have a thickness of at least 250 mm. The smallest content value is 1 cm; The largest, according to various sources – 16, 22 or 25 cm.
Undoubtedly, the classical technique is based on 2 sides. In this case, the bending occurs under the mass of the load, and the armature picks up the created voltage. The main condition for success is the correspondence of the created load and plates parameters. Sometimes they try to paint on 3 sides. This technique has an alternative name – Opportion with a valve.
Such an approach is admissible if it is impossible to put the plates in width, and the monolithic block does not make sense. Technically, a similar solution is worse than a support for 2 sides. Plates on the long side undesirably to start the wall with a depth of exceeding the thickness of the product itself. Otherwise pinching. They are especially dangerous for prefabricated structures.
It is categorically impossible:
- Operate the slab on two long sides;
- put an auxiliary support in the span;
- Get a slab on two walls, pulling out a piece as a balcony or console.
Arrangement of the Outrition Plate
To reduce the freezing, it is required to close the holes that are inside the hollow plates. More correctly and easier to do it when the designs are still on earth. Plates of overlapping from aerated concrete put on reinforced concrete seismic belts. Mandatory requirements will be:
- symmetric layout;
- deviation from ideal planes not more than 5 mm;
- bunch of plates with a belt using welding, providing high strength;
- The fill of anti-seismic lines for the width of the walls.
It is necessary to put heavy slabs with a crane until the solution froze. The solution should be dense, it is not necessary to dilute it with water.
Important: The surfaces of the bearing walls before forming the overlap should be aligned as much as possible. If it is necessary to describe the slab on the three sides, it is necessary to strictly be guided by the scheme proposed by the manufacturer. When there is no such scheme on the site, it is better to clarify everything additionally, feeding the request.
Formwork for reinforcing belts should be made from any materials with reduced hygroscopicity. In the absence of experience, it is advisable to order a finished formwork. Given the probability of the penetration of the cold through the reinforcing belt, it must be insulated. It is unacceptable to apply a brick or grid layers instead of a full-fledged armoeaction (both together and separately). In some cases, concrete ring anchors are used.
On how to install the slabs of overlapping correctly, look next.