If you ever faced with the question of building a summer house, your own home or apartment renovation, then you should know what are hollow core slabs, the technical characteristics of which will be presented in the article. If you know the design features, as well as the characteristics of the product, using the information provided by the marking, you can determine what limit the decorative payload is capable of undergoing the floor slab.
The main varieties and positive features
Hollow core slabs, the technical characteristics of which will allow you to carry out construction or repair, excluding errors, differ from corpulent products in less impressive weight and affordable cost. But their reliability and strength are not lower. The number and arrangement of voids are not able to reduce the bearing characteristics. On the contrary, thanks to this addition, the heat and sound insulation features of the building increase. Among the positive characteristics, one can single out the popularity of the need for the construction of reinforced concrete multi-story buildings, monolithic buildings and private houses. There are frequent cases when the described plates become part of the supporting frame of the building.
Dimensions and Weight
Hollow core slabs, the technical characteristics of which you should be interested in before purchasing these products, can have different costs depending on size and type. Dimensions range from 1.18 to 9.7 meters, as for the length. Whereas the width varies from 0.99 to 3.5 meters. The most common products are those whose length is equivalent to 6 meters, the width of the most purchased plates varies in the range from 1.2 to 1.5 cm. A constant height is the height of the plate, which is 22 cm. Hollow core slabs, the technical characteristics of which are presented below, have very significant weight. That is why for their installation there is a need to use a mounting crane. Lease should be one that has a capacity of not more than 5 tons.
If we are talking about a slab whose dimensions are 1680x990x220, then its weight is 0.49 tons.
Specifications
To purchase products it will not be enough to know only the weight of the floor slabs. It is important to familiarize yourself with the main technical characteristics. As raw materials in the manufacture of concrete is used, which is performed using cement brands M300 and M400. The numbers will determine the qualitative features of the material, which ultimately will be characteristic of the finished product. Thus, cement M400 is able to undergo a momentary load equal to 400 kilograms per centimeter cubic per second. As for cement of the M300 brand, it is a derivative of the mixture from M 400. Despite the fact that this material is able to withstand a less impressive load, it is ductile, which ensures the exclusion of a break during deflections. If you decide to purchase hollow core slabs, the technical specifications for the load presented above should interest you. Among other things, reinforcement is used to strengthen products, which provides an impressive bearing capacity of the monolith. In the manufacturing process, stainless steel grades A3 and A4 are used. It is characterized by increased resistance to corrosion processes and temperature extremes. Thus, products can be operated from -40 to +50 degrees.
Bending Stability
Despite the fact that the weight of the hollow core slabs is quite impressive, they do not bend during operation. This effect was achieved by the method of advance tension of the reinforcement, which is able to distribute the voltage of the elements over the entire area. After the concrete hardens and becomes strong, the stretched elements are cut off. At the ends, which the plate rests on the supporting walls, lay double reinforcement. This eliminates the deformation under pressure of the weight and provides the ability to undergo a load from the bearing upper walls.
Characteristics of plates depending on the marking
Hollow core slabs, the characteristics of which must be known before purchase, are marked. Products are designated by two letters - PC. The following is a number that indicates the length of the product in decimeters. The following numbers are approximate widths. The last indicator indicates how much weight in kilograms can affect 1 square decimeter of the plate, taking into account its own weight. Thus, if you have a plate with a PC marking 12-10-8 in front of you, then this indicates that the length is 1.18 meters, which is approximately 12 cm. The width is equivalent to 0.99 meters. As for the most impressive load that the product will be able to undergo, then it is equal to 8 kilograms per square decimeter. The last value is 800 kg per square meter.
Additional information on possible loads
It should be noted that reinforced concrete hollow core slabs are able to undergo the aforementioned load, this indicator is the same for almost all hollow concrete reinforced concrete products used as floor slabs. As an exception, we can distinguish products that undergo weight up to 1000 and 1250 kilograms per square meter. Such plates can be recognized by marking, which ends with the numbers 10 and 12.5, respectively.
Influence of characteristics on installation features
As the main rule of reliable device construction, compliance with the rules governing the support on the walls acts. If the area of support is insufficient, then the walls can be deformed. Whereas excess area will lead to increased thermal conductivity. The support of hollow core slabs for brick construction should be 9 cm. If we are talking about foam concrete and aerated concrete, this figure increases to 15 cm. For steel structures, the figure should be equal to 7.5 cm. In this case, the greatest deepening of the products in the walls should not turn out to be more than 16 cm for brick structures and light blocks. For concrete structures and reinforced concrete analogues, this figure is equivalent to 12 cm. Before installing the slabs, the edges of the voids should be repaired with a lightweight concrete composition, deepening by 12 cm.
Additional installation recommendations
Hollow core slabs, dimensions, GOST of which are indicated in the article, should not be laid without mortar. A mixture layer is laid on the working base, the thickness of which should be equal to 2 millimeters, but not less. This will provide an opportunity to evenly transfer the load to the wall structure. Among other things, when installing plates on brittle walls, for example, made of gas blocks or foam concrete, the mixture reinforcement technology should be used, which eliminates the possibility of block bending. In order to reduce the quality of the thermal conductivity of the floor, it is necessary to warm the structure from the outside.
GOST 9561-91
According to state standards, hollow core slabs are installed on the supporting structures of buildings and structures for various purposes. In the production process, concrete is used, with the help of which products are formed with a thickness of 220 millimeters. Inside there are round voids that have a diameter within 159 millimeters. From the central parts of two adjacent voids, the step is 185 millimeters. Hollow core slabs , dimensions, GOST of which are indicated above, have frost resistance, which is determined by the brand F200. It is necessary to purchase plates, the manufacture of which was carried out in accordance with the rules of state standards.