A plinth, also commonly known as a plinth beam, is a reinforced concrete base that is constructed between the wall and its foundation. What makes a plinth vital for construction projects is its tendency to prevent the foundation and structure of a house or a building from cracking or eventually falling.
What is the Purpose of Plinth in Construction?
Plinth Meaning: A plinth is typically a rectangular block, made of bricks and concrete, on which the pillar and columns stand afoot and give the building its foundation. The column holds the weight of the building and is pressed down in the process.
Plinth beams work to distribute the load and weight of a wall on the foundation to give your building structure the strength that it needs for standing its ground for years and years to come.
Plinths are skeletal systems constructed of steel bars and concrete that make up a solid frame structure. The plinth bricks and beams are one of the foundational elements of any construction project.
Benefits of Plinth in Construction
Let’s take a quick look at some major benefits of incorporating plinths in construction.
Shields from Moisture
The plinth in constrcution acts as a barrier that keeps the moisture and dampness away from the building structure. Moisture can lead to cracks, fungus, and, eventually, a weakening structure that can be very dangerous.
In addition to this, these prove extremely beneficial in preventing water seepage in your house or building. It acts as a waterproof element for the foundation and keeps your building structure intact.
Even Distribution of Weight
It acts as a retaining shield that keeps the concrete layer grounded below the building floor. This is possible due to the horizontal layout of the plinth, which disperses the load of the columns on the foundation in an even manner.
Elevation & Aesthetics
Plinths give an aesthetic and neat touch to the building structure, given that it is built on a strong foundation. Compared to average-built houses, which are constructed 150-300mm above the road level, a plinth area can be fitted in the soil and fill up the space in the soil and foundation. This gives your building strength and durability.
What is the structure of the Plinth Itself?
Plinth beams involve several elements that make up the foundation.
The first step is laying out steel bars horizontally and vertically, similar to that of a chessboard print. The next step is assessing the strength and concentration of the concrete that is used for making the plinth more durable.
After this, the minimum dimension for the plinth level height in feet is determined. Once this is done, the plinth beams are installed in the process of shuttering.
Steed Bars for Plinths
Plinths are constructed with a basic structure that involves two steel bars, with a minimum diameter of 12mm, set at the bottom-most level of the beam. With this, two bars with a minimum diameter of 10mm are added at the top of the plinth beam. This is then covered with reinforcement bars, which are then covered with a layer of 25mm of concrete.
For the stirrup diameter, the standard requirement is at least 6mm with a gap of 15 cm. The plinth level for a building is usually determined to be above the adjoining road level. This is to avoid any downpours in your house in case of heavy rainfall.
Concrete Structure Strength
The concrete mixture for the plinth beam has to be of a specific strength that is suitable according to the building structure under construction. However, it should not be more than 20 MPa, with an ideal concrete mixture that has a ratio of 3 parts sand, 2 parts gravel, and 1 part cement.
If you are manually preparing the mixture for the concrete cover, you need to add 20% cement.
Dimension of Plinth Beam
Although the dimension can vary when it comes to the complexity of the projects, the minimum dimension of a plinth beam needs to be 20 cm, whereas its width is relative to the foundation of the house.
Both the beam and pillars depend on the size and surface area of your building, whether you’re building a single storey or a multiple storey building.
Shuttering of the Plinth Beam
Shuttering is the procedure of holding the wet cement with molds till the cement drys out and forms a solid structure. When shuttering the plinth beam, the columns are bound by steel bars and then filled with a concrete mixture.
The ground beam should be developed carefully, with a minimum of 150mm in the natural ground, so that soil-filled within becomes compact and makes the structure durable. The shuttering should be done tightly with no room for seepage of cement; only then a neat and durable beam can be formed.
Plinth Beam Application
Regular earthquake jolts now and then can eventually lead to cracks in foundation walls, which makes the application of plinth beams essential for construction in natural disaster areas. They make buildings stand their ground through natural disasters, compared to other types of structures.
Other than this, these beams help with the smooth flow of the sewage system in a building. This is because the building is elevated above the road level and the sewage water and drainage flow down to the drain, which is at the bottom-most ground level. Get to know how to improve bearing capacity of soil?
Plinth beams have reformed the construction industry and provided durability to projects.
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