Concrete floor slabs - product classification, designs from

Concrete slabs for ceilings began to be used from the moment of mass production of concrete products. Experts from all over the world recognized that this option for arranging interfloor structures is the most convenient and cost-effective. Until recently, they were made of high strength concrete sorts, but now light, cellular types of material have been widely used.

Plate Types

Extensive experience in the use of this material in construction causes a fairly wide range of products presented. Of course, in each niche there is a detailed classification according to its GOST standards. But, despite this, the production of all products can be divided into several areas.

Product classification

• Solid or solid cast plates, marked as TCP. They are monolithic structures reinforced with a steel frame. Have a high degree of concrete strength, as a rule, are used in buildings with a large design load. In particular, widely used in industrial and high-rise construction. But the scope of use is significantly limited to a serious mass.
• Ribbed products marked as MFR. They represent a monolithic plate equipped with stiffeners, which can be located in one or in two directions. Most often, with the help of these structures, the installation of floors or floors is carried out in industrial buildings, matting, warehouses, etc. Due to the reinforcing ribs have a relatively high resistance to mechanical loads.
• In private and residential construction, hollow slabs are the most common, they are marked as PTM. These products have in their design oval or round voids located inside the plate. Due to this feature, they have high heat and sound insulation. Plus, not least, the weight of the concrete floor slab with internal voids is significantly reduced.

Concrete products

As mentioned earlier, this type of product has been produced for quite some time.

In the construction of the majority of existing at the moment, high-rise buildings and low-rise buildings, it was used such concrete products.

• Virtually all concrete products plants produce a certain range of floor slabs. The length of the product can vary from 1600 mm to 15m. The width of the size range is also quite large from 600 mm to 2.4 m. The thickness of most commercially available products is 220 mm. The weight of the concrete slab may vary, depending on the size of 0.5 - 4 tons.

It is important: to think about what dimension is suitable for your home better in advance. And immediately find out whether the factory of concrete products closest to you produces such slabs. Because the cost of concrete slabs, necessarily include transportation costs. The price for the same product may vary significantly depending on the distance.

• The dimensions of the concrete slabs have the widest range, so not every plant can meet the size that you need specifically. Traditionally, the grade of concrete for the floor slab is taken M200 - M300. But for low-rise construction, you can use the products of the brand M150. Plus, most factories can work individually, but the price will be higher.

Polystyrene Constructions

• Polystyrene concrete is one of the varieties of cellular materials. It appeared relatively recently and is a product of modern technology. This material has good strength and a fairly low weight, so that it is widely used in the construction of modern buildings with a large number of floors.
• In addition to the uniquely high performance characterizing sound and heat insulation, polystyrene concrete floor slabs have a very low moisture absorption coefficient. Due to this, the floor slab of polystyrene concrete practically does not get wet and does not freeze through. Plus possesses high adhesion, does not require arrangement of additional screed and reinforced waterproofing.

Expanded clay structures

Slabs of ceramsit concrete, as well as building blocks of this porous material, are now particularly popular with residents of Western Europe. This is explained by the fact that this material is considered to be completely environmentally friendly.

It consists of cement, sand and a specially baked clay.

• By themselves, expanded clay concrete floor slabs, like all porous concretes, have high heat and sound insulation. The material is strong enough to compress, but the elasticity of expanded clay concrete leaves much to be desired, so these plates require more dense reinforcement using metal beams and channels.
• This material is often poured directly at the place of installation with their own hands. For this, the bottom space is hemmed with corrugated metal sheets, grade HC35, HC44 or H57. Then it is well reinforced, the formwork is exposed and the solution is poured.

Foam concrete structures

Homeland of this material is Germany. He appeared at the beginning of the nineties. Made from a certain type of cement, sand and special additives.

The production principle is similar to the yeast dough, all components are combined in a ready-made form, baking powder is added, due to which the mass "rises" and the concrete product hardens.

• This material is appreciated for its ease. But there are downsides. So foam concrete floor slabs need good waterproofing. The fact is that the material is capable of absorbing moisture, therefore, in winter conditions, if the lining is made incorrectly, the blocks can freeze and collapse.
• Blocks of foamed mass, like blocks on the basis of expanded clay, are afraid of mechanical loads on bending. For this reason, foam concrete floor slabs are most often used in low-rise construction.

General installation tips

• Preparation for installation begins at the stage of building walls. At this time, bricklayers should put horizontal marks that will be a guideline for a smooth installation of the slab.
• If brickwork is being made, then the top row should be made using the bonded method.
• If the plates are stacked on the bearing partition with a thickness of at least 1.5 bricks, then it is desirable that the top was made of solid bricks.
• It is advisable to lay voids in the slabs on both sides, and still while the product is at the bottom. As a rule, voids are sealed at the factory, but after transportation it is better to control.
• Installation instructions for floor slabs, with all the norms and tolerances prescribed in SNiP 2.08.01-85. But experienced builders are advised to rest the design on 2 short sides, approaching the wall about 120 mm.
• There are often disputes over whether it is possible to mount a concrete slab with a support on 3 sides, that is, on 2 short sides and 1 long. According to the same norms of SNiP, this is possible, but under the condition of special reinforcement.

Important: it is extremely undesirable to lay the structure on 2 short sides, plus a transverse support in the form of a pier in the middle. The plate may crack, and unpredictable. If such a need arises, then reinforced concrete is cut with diamond circles to the depth of the circle in the middle of the transverse support. So, if the stove cracks, then in a safe, pre-planned place.

Mounting on porous blocks

If the slabs are laid on ceramsite concrete blocks or another porous material, then heavy structures cannot be mounted directly on the supporting walls, they can quickly collapse.

In this case, proceed in two ways.

• First, if the blocks are monolithic, then in the area of ​​the interfloor overlap a formwork is equipped, a reinforcement cage is laid into it and concrete or cement-sand mixture is poured.
• Secondly, the best and more convenient way will be to buy special porous U-shaped blocks, which are designed for mounting reinforced structures inside them and pouring them with concrete. This belt will be less noticeable, but also durable and reliable.

Important: if the slab needs to be cut, then in addition to diamond discs, diamond drilling of holes in concrete is used. At first, at a distance of about 100 mm, a series of holes are made. After that, you need to cut a diamond disc. Next, the product is cracked with a crowbar and a sledge hammer, the reinforcement can be cut with a grinder or gas cutter.

The video in this article shows some more useful tricks.

Conclusion

Of course, the question of how much a concrete slab costs is important. But in order not to throw out extra money or not to bother trying to cut the product, we advise you to decide in advance exactly what size and material you need.