# Estimating is so complex Sir ….

Friends ,

If you learn the art of estimation , you shall increase your employ-ability.

If you know how to calculate the weight of Rebars at site , jobs shall be waiting for you.

Today we are going to do one estimate in easy steps.

Its a RCC beam. We shall calculate the complete material cost for this beam.

You know that we shall need following materials for casting of this beam.

1. Cement
2. Sand
3. Aggregates
4. Water
5. Reinforcement steel
6. Binding wire

We shall find out the quantities of each of these materials and finally , arrive at the material cost.

So , let us start with the basic appearance of this beam.

This looks like this :

The span of this beam is exactly 8m.

You already know that for calculations of the beam re bars                                                                , we need to consider the OUT to OUT dimensions of the RCC beam.

OUT to OUT span = Clear span + Column widths on both ends.

The RCC drawing for the beam has been re-drawn here for better understanding :

Please note that for simplicity , the development lengths of the beam bars [ also known as ” L ” at site have  not been shown in this sketch and also have been omitted during the calculations . But , on actual site work , we must add this   ” L ” as given in the RCC drawing .

The ” L ” shall look like this :

Now the actual exercise can be stated as follows :

Now let us start with the actual calculations.

The most difficult part is probably the bent up bar.

Lets see these calculations in detail here :

The calculations for the remaining bars shall be as follows :

Now , lets make a summary of the Rebars at one place :

Now its time to go for the RCC elements .

Going further , we calculate the materials as follows :

So , now we have the quantities of each of the required material.

Lets make an abstract of the final cost.

Hope you have enjoyed the computation part.

In case of any queries , don’t hesitate to post your comment here.

And , if you have really liked this , please ” LIKE ” it on the blog so that I know .

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## 5 thoughts on “Estimating is so complex Sir ….”

1. Sundarrajan says:

Nice explanation sir, it will be good if the value 0.41H is explained how it is come to calculate the bent up length.

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2. wazedpasha syed says:

as sundarajan asked how 0.41H is explained to calculate the bent up length ?

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1. Santosh Kulkarni says:

Great.
Shall post an article on this query by today noon.
Thanks

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1. Santosh Kulkarni says:

Hello ,

This is an excellent question.The answer shall be interesting. Can we have a separate post for this ?
Thank you for the suggestion.
Stay in touch.

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