7 common mistakes in the plinth beam./ Plinth beam construction process./How to avoid mistakes in a plinth beam?

While providing a plinth beam for the building, some common mistakes which I have observed are given below. 

1.  Development length:

Provide the rebar with the needed development length and 10 times bar dia. which is given as Ld + 10Db or say L -length/ hook. Curtailing the bar at the column end is technically wrong.

 2.  Bar diameter:

The diameter of the bottom reinforcement should not be less than 12mm (IS 456) and the top rebar should not be less than 10mm. diam. as shown in the drawing. Providing the rebar of 10mm. and 8mm dia. is one of the mistakes which should be avoided.

 3. Nominal & clear cover :

Providing the cover for the reinforcement bar on all 4 sides is essential, as shown in the drawing, but when the beam is placed over the brickwork, avoiding cover for the bottom rebar is a wrong practice.

 

4. The spacing of the stirrup :

Providing a spacing of 150 -175 mm at the center and 125 - 150 mm near the column end is a good practice to avoid the settlement of masonry work. One of the mistakes done here is keeping the spacing at 300mm and above, to save the stirrup rings is a mistake that should be avoided.

To know the checklist for beam shuttering, go through the article👇

👀. Checklist for beam shuttering./What are the points to be checked in beam formwork?

5. Ld at the T- junction :

 As explained earlier, the development length Ld should not be curtailed at the junction of the 2 beams or at the T formed at the column and another plinth beam.

 6. Cleaning the beam:

After completing the plinth beam work for the building, usually, the next procedure followed will be moorum filling in the plinth. After completing the filling work, the contractor on the site, neglect to clean the plinth beam surface. 

 Brick masonry work built on such an uncleaned beam top will result in weak bonding and ultimately ends in the cracks at such joints. Please take care to clean them properly.

7. Formwork :

Using building blocks or bricks as the side formwork for the plinth beam is also a mistake. Do you know why? The reason is, they absorb the water and cement slurry, making the weak concrete of different grades.

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Thank you for going through this article❤. Have a good day 😄.

If you want to understand them in a better way with an explanation, click on the video given below

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