What is a block beam and what are its components?
One of the most widely used roofs in all kinds of buildings is the block beam. The use of block beam ceilings for a structure is on the agenda most of the time due to the ease of implementation, high speed and no need for an expert team in the implementation, and it is the first priority of employers in choosing a roof. In this article, we will examine the details and components of the block beam roof.
What is a block beam and what are its components? Review the pros and cons
With the passage of time and by applying engineering sciences and material metallurgy, new methods for building construction have been invented. Engineers and designers are always trying to eliminate the defects of the previous methods and improve the strength of the structure in new methods. Block beam roof is one of the types of building roof that has been used in buildings from the past until now, and for its construction, a combination of beams and cement blocks is used.
Of course, sometimes clay block or unolite will also replace cement block. However, what is evident is that the use of blocks in the roof has a filling role and does not interfere with the strength of the structure. Therefore, the filling material or block has no effect on the strength of the structure, and the duty of bearing the forces applied to the building is the responsibility of the types of beams used in the roof. As a result, the quality of the beam is very important. Of course, it should be noted that the beam is also used as a secondary beam in the roof.
Block beam roofs are economically affordable and this feature has made its use in building construction to increase day by day. In order to build block beam ceilings, prefabricated materials and concreting are used at the same time.
Components of block beam roof
To form a block beam roof, a number of T-shaped beams are placed next to each other. Block beam components include beam, block, thermal rebar, middle coil and cover concrete. In Iran, usually the beams are of concrete type. The molds of these beams are often made of clay or metal, and the metal ones are known as temporary molds and the clay ones are known as permanent molds.
beam
3 types of upper, lower and shear rebar are used to reinforce the beam. The truss rebar has a size of 6 to 8 mm and the upper truss rebar has a size of 6 to 8 mm and is of compression type. The lower rebar is of tensile type and its size is 6 to 16 mm. With the help of trusses, the compressive and tensile strength of reinforcements can be increased and the structure can be prepared to bear heavy loads. Continuity between concrete and rebar is very important and it is better to use ribbed rebars for greater continuity.
Block
Clay, concrete and unolite are the materials used to make blocks. The blocks are usually made in the dimensions of 40*20*25 and if a thicker block is needed, two-piece blocks are used in the structure. Blocks are usually produced with a small weight so that the weight of the dead load is reduced and the load applied to the structure is not increased.
Covering concrete
Covering concrete, which is also called top concrete, has a thickness of 5 cm and with the same function as a horizontal shear wall, it controls the performance of the diaphragm of the roof created under seismic force.
3 important points regarding the implementation of the block beam ceiling
The distance between the axes of two beams placed behind each other should not be more than 70 cm and the width of these beams should not be less than 10 cm.
The thickness of the block beam roof for single-headed beams and beams with simple support should be equal to one twenty-sixth of the length of the opening and one twentieth of the length of the opening, respectively.
What are the advantages of the block beam roof?
As we said earlier, the use of this roof has many features, which we will discuss further:
One of the advantages of block beam ceilings is not requiring complex materials for execution.
There is no need for an expert force to implement block beam ceilings and all the implementation costs of these ceilings are more suitable than some other ceilings.
The existence of a series of plastofoam blocks in beam roofs creates a suitable insulation block for these roofs against heat and sound.
Block beam roofs have better resistance than some roofs.
In addition to increasing the speed of construction, block beam roofs are lighter than some roofs such as solid concrete slabs.
The implementation of block beam ceilings in an area of 100 square meters will take about a week to 10 days.
If we want to point out one of the most important advantages of these roofs, we must say the implementation of negative rise in the series of block beam roofs.