گروه صنعتی ایستافرم تولیدکننده قالبهای یوبوت u-boot 
The Concept Of Voided Slab U-Boot
Today, the concrete flat slabs with conventional reinforcement can be used in large openings. Some of the progress made in the field of technology and reinforced concrete flat slab concrete reasons for the implementation of long-span is as follows:
– The use of high-strength steel reinforcement
– Use negative reinforcement in the slab to reduce the deformation of the upper side of the slab of multi-span
– The use of high-strength concrete slabs
– Using the new formatting systems indicates that in addition to the possibility of arbitrary geometry, reduced administrative costs as well.
A designer can according to the reinforced concrete ceiling systems, ceiling systems suitable and economic choices. Reinforced concrete ceiling system in addition to the economic plan should consider the following points:
– The ceiling should have sufficient strength to withstand the applied loads.
– To limit deformation under load permanent and non-permanent values should provide hard evidence is needed.
– By increasing the size of craters, hardness is more important. In this case it is possible to measure the resistance, hardness determination is the main dimensions.
As noted above with increasing difficulty slab can be covered more openings. The fact that the aid system is Formatting possible cause of difficulty is different slabs, some of which include:
– Flat slab
– Inscriptions flat slab (mushroom)
– Slabs with secondary beams
– Voided slab
In slabs caved in, using a grid of orthogonal beams under the main slab, reduces the amount of concrete, reinforcement and at the same time reducing the weight of the ceiling. However, in this system indicates the difficulty level increases. The increasing difficulty of creating T-shaped cross-section is in evidence.