Introduction to grade beam foundation
The pile caps and footing is tied with the help of horizontal ties, and these horizontal ties are known as grade beams. Before diving in further, let’s understand what is grade beam foundation?. It is a part of constructing a building that helps transfer the load to the foundations and comprises the reinforced concrete beam. The burden is shared with the caissons or the pile caps. Overall, the grade beam is an essential part of the whole structure. These beams act as a vital connection point or have a strong bond between the piling caps and the footings. It nicely avoids and controls differential soil settlement and supports the loads at the earth level.
The grade beam foundation shares all the load to the undersoil Strata. The load intensity on the beam is also a factor that determines the depth and size of the grade beam. If the minimum depth of the grade beam is considered, then it should be 150 mm and ensure that the grade beams have more strength than the plinth beams. If both grade beam and the conventional foundation are considered, the traditional foundation uses a high amount of reinforced concrete compared to the former one.
What are the steps involved in grade beam construction?
Several steps are involved in the development of the grade beams. You can have a look at the below-mentioned steps.
- Grade beam excavation and preparation
Before grade beam construction, it is crucial to excavate after investigating the site level. The pile construction will be finalised when the grade beam is planned to connect the two piles. These are steps necessary before the grade beam preparation.
- Formwork installation for Grade beam
Formwork installation after the excavation part is the foremost part of the grade beam construction process. For installation of the formwork, it is essential to look at the dimensions accurately. You need to check the dimensions of the grade beam. The bottom of the formwork should be replaced before its sides when the construction of the grade beam has been done on the ground.
- Reinforcement placement of the Grade Beam
As soon as the formwork is done, it is time to reinforce the grade beam. The reinforcement placement of the grade beam needs to be done after analysing the structural drawings. The structural picture comprises the size and number of the reinforcement bar. Well, it is essential to check the necessary detailing after reinforcement placing.
- Concrete Pouring for Grade beam
Mix concrete or on-site machine mixed concrete is used for casting the grade beam. This process of pouring the grade beam is the last step and while casting, ensure the concrete material is adequately compacted. The top of the grade beam needs to be appropriately finished. The constructing team can remove the grade beam after 24 hours. Also, release the border shutter when the concrete has strengthened fully.
Some frequently asked questions
- When and where to use grade beam?
When there is a need to connect the foundations and is used where the surface has less capacity to bear the structure’s load, grade beam construction is a method to connect the two columns.
- Which is more substantial, Gradebeam or plinth beam?
Grade beam has more strength than Plinth beam. The framed reinforced concrete structure built between the foundation and the wall is known as the Plinth beam.
- What is the standard size of the grade beam?
The standard size of the grade beam depends on the type of building. In the case of a residential building, the standard length is 9″ * 12″ or 225 mm * 300 mm.
Constructors can quickly form grade beams in different sizes and shapes, resulting in excellent support to the surface. The most significant advantage is that you don’t need to excavate because less excavation is required during installation. With the construction of beams, the project cost gets reduced. With many advantages, there are some disadvantages, And these are that for grade beam construction, the site should be levelled as it is not done in hilly areas and basement. However, a whole grade beam foundation is the best technique to apply when the soil has less- load-bearing capacity.