In conventional beam and block ceilings, the beams are produced in two types, steel and concrete. Based on this, the method of producing beams is different based on its type, which is explained below on how to produce each type of beams. Concrete beam, lattice beam truss is a prefabricated network of tensile and transverse reinforcements and upper connection bars, which are welded to each other in the form of a truss and provide the necessary stability for transportation and execution. The steel used for the construction of the truss, in addition to having sufficient elastic modulus, must be weldable and have the minimum allowable strain (relative length change) at the breaking stage. This strain is limited to 20% in the case of soft steels, 18% for semi-hard and hard hot-rolled steels, and 8% in the case of modified steels. For this purpose, two methods of resistance welding and electric arc welding are used. Steel beams with open life are simple two-headed special trusses that are used to evenly distribute the load of the roof to the supports. The production of this type of beams includes the production of the lower wing, diagonal member and upper wing and the connection of these members (as usually by welding) which is produced in the factory and transported to the workshop
Executive Specifications and Technical Specifications of Block Block
There should not be any waste in the molds before concreting. The heel concrete should be poured flat and the minimum thickness considered should be 10 cm in order to provide proper support for the blocks. If you want to use the beam in the open air, you must first fill the bottom surface with sand and cement with a thickness of 15 mm. In order to use this type of roof in brick buildings, you need to run horizontal shims on the load-bearing wall. For multi-storey parking lots and on the floors on which the car is placed, the block beam should be used in double form. There is a need to use reinforcing bars when using ready-made block beams. Pouring concrete on the roof should be done with one hand and without a time break. The maximum distance from the axis to the axis of two consecutive beams should not be more than 70 cm. The covering concrete of the upper part of the beam should be less than 5 cm or one-twelfth of the distance from the axis to the axis of the beams. The width of the beam should not be less than 10 cm. The minimum distance between the blocks on both sides of a beam after installation should not be less than 6.5 cm. The diameter of the roof for beams with simple support should not be less than one twentieth of the opening. . A very important point that must be taken into account when implementing the block beam is the location of the holes that must exist in the roof due to the necessity of facilities or architecture; Because if these holes are to be created after the construction of the roof and by destroying parts of the roof, dangerous and irreparable damage will be done to the strength of the building.
