Lintel and Function of Lintel and also classification of lintels.

      Lintel: Lintel is a beam like structural flexural member used to span over the opening of doors, windows and cup-boards.

     Function of Lintel:

(1) Lintel are placed over the openings of doors and windows, as the frames of doors and windows    are not strong to support the weight of wall above the opening.

(2) It is a beam like structural member, which transfer the loads acting over the opening to the support of the wall.

Classification of Lintels: 

Types of Lintel

While timber is as yet utilized in the development of homes, heavier materials, for example, block, concrete, and stone, can likewise be used, particularly in the event of business structures and private condo squares. Thus, the utilization of stirred steel lintels has developed increasingly well known. Depending on the costing and availability of materials, different materials are used for lintel construction. Lintels are classified into the following types according to the elements of their development:

Based on the type of material used, the lintels are classified as follows:

(a) Timber lint a) Timber lintels. els.

(b) stone lintels.
(c) Brick lintels.
(d) Reinforced brick lintels.
(e) Steel lintels.
(f) RCC lintels.
(g) Thin lintels.
 
 a) Timber lintels

Wooden or Timber Lintels are the most seasoned sorts of the lintel. They are fundamentally used in the hilly areas where timbers are accessible. But in open areas, uses of timber are constrained as a result of the significant expense and accessibility of present-day materials. If there should be an occurrence of more great dividers, timber lintel is made out of two wooden pieces avoided as much as possible with the assistance of wooden separation pieces.

 Sometimes, timber lintels are reinforced by the arrangement of mild steel plates at their top and base; such lintels are called flitched lintels. It has a few other disadvantages-

• It is less durable.
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The mainly used as lintels in the construction RCC lintels and Thin lintels.

(a) RCC Lintels: Rcc lintels are constructed with a concrete mix 1:2:4. The amount of reinforcement and depth of lintel depends upon the span of the lintel and amount of load to be supported by the lintel.

At present, reinforced concrete lintels are very common in use. In this type, reinforcement is used to overcome the low malleable issue in concrete. They are developed in present-day structures. They are suitable for heavy loads and larger spans. Their thickness is kept around up to 8 centimeters for every meter. RCC lintels can be either precast or cast-in-situ. Generally, precast reinforced cement concrete lintels are used when the lintel span is smaller. Lintel width should be the same as wall width. The depth of the lintel depends on the length of the span and the loading's magnitude.

Concrete, though strong in compression, is fragile to tensile stress, so main reinforcement bars are used at the bottom to resist the tensile stress. Half of these bars are cranked at the ends. Shear stirrups are provided to withstand shear stress.

(b) Thin lintels: are nothing but RCC lintels having a thickness of about 75mm to 100mm only. In this lintels it is considered that RCC thickness of about 75mm to 100mm forms the tensile zone only.Hence it should be built with CM 1:3.