FOUNDATIONS…beginners guide

Dear Friends ,

Good evening !

The design and selection of a particular type of foundation is a work of the RCC consultant The construction person must know the background so that the interaction with the designer is easy. Read this article so that you know the basics.

 

 

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Calculate Cutting Length for Rings… so easy.

Hi dear friends ,

Good afternoon.

A hearty Welcome to the recently joined followers.

We are now a 585 strong construction team .

Just think , together we can undertake and successfully complete any multi crore project.

By the way , ” Your Question bank ” has been released to many followers on request.

Those who have the desire to obtain a copy , kindly refer to this post :

HOW TO USE THE QUESTION BANK ?:

Today you shall understand the theory and practice behind the stirrups.

Stirrups are also called Links or Rings or Transverse Reinforcement.

These are used for Beams and Columns.

In a Beam , the stirrups are vertical and in a column , these are horizontal.

RINGS IN A BEAM

RINGS IN A COLUMN

Each ring has a HOOK at one of the corners which keeps the ring in its shape. The ring shall open if this hook is not given.

Look at this chart to understand about the calculations of the hook length :

look at this detail usually given in a RCC drawing :

Now let us solve an example and find out the cutting length for LINKS for a column

Now let us  take another example :

Hope you are getting the whole picture :

Now try your practice with this example.

Here is the answer :

Now let us take a complete example :

Now , let us see what all we need to find out :

here is the solution :

Now it is the right time to share with you a simple short cut :

In case you would like to have a formula that can be used for any cover , any hook length , this is it :

 

RCC DRAWING….DIFFICULT TO READ ?

Dear Friends ,

Today we shall study the RCC drawing , find out the details of a Plinth beam and then work out the REBAR weight .

First , let us define the problem :

Yeah..the Slab is finally cast

Overview:
In this series  we are looking at the various stages in the construction of a building.
So far we have covered from land acquisition up to mobilization and from mass excavation up to columns of the first floor.
This article brings you the intricacies and steps in casting the roof slab.

For the purpose of clarity, the tasks have been grouped under:

A. Pre-concreting care:
B. During concreting care:
C. Post -concreting care:

All the Activities ,however, have been sequenced in a continuous serial nos from 1 to 47.

The activities sequence:

A.Pre-concreting care:

Columns:
1.Columns up to beam bottom
2.Curing of columns
3.marking of beam bottom on columns
4.fixing of runner blocks on columns

Beam bottoms & sides:
5.Fixing of beam bottom
6.Supports below beam bottom
7.Inside face of beam: side fixing

Slab centering:
8.Slab centering in plates
9.Gaps fixing with planks & closing of gaps qith iron strips or masking tape.
10.Fixing of Accrow spans
11.Levelling of centering plates
12.Keeping camber in the slab

Reinforcement laying:
13.laying of beam reinf.
14.Laying of slab reinf.
15.placing chairs below bent up bars

Electrical conduits/ fixtures:
16.Laying electrical conduits/ fan hooks/ down pipes from beams

Sunk portion:
17.Keeping pipe sleeve in the sunk portion for drainage pipe

Securing:
18.Placing cover blocks for beams & slabs
19. Fixing clamps for beams
20.Fixing tie bars in sleeves for deep beams

Joint inspection:
21.Steel measurement and checking
( jointly with clients engineer)
22.Laps counting
23.Extra bars counting

Arrangement for casting:
24.Installing the concrete pump
25.Fixing the pipes for concrete
26.scheduling the transit mixer ( TM)
27.Final checking by consultant
28.pour card approval

B. Care during concreting :

29.Placing concrete
30.Compaction by needle vibrator
31.levelling
32.slab thickness verification
33.finishing
34.Removing excess debris from slab

C.Post concreting care:

35.casting of specimen cubes
36.providing mortar bunds for curing
37.ponding with water
38.striking off beam sides
39. striking off slab centering
40. striking off beam bottom
41.Hacking the concrete surface
42.Sunk portions cleaning
43.waterproofing
44.ponding with water
45.Testing of cubes on 7th & 28th days
46.Reconciliation of materials
47.Bills

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Quandary of construction ?

Construction starts with a dream of the builder and gets completed when the final cheque from the last customer is realized
In this article we are going  to review various decisions one has to take before the actual construction starts.

1.Lone crusader?
The first decision which a builder needs to take is whether he shall be working alone on this project or needs a financier with him.

This has a few situations ;

1.Working with own funds

2.Having a working partner with him who shall also do part of the investment.

3.Having a sleeping partner [ financier] who shall not be operationally active.

4.To take loan from financial institutions.

Each decision has its own merits & demerits.

2.Own land ?
Having decided mode of finance , the next decision is whether to construct the building on own plot or it can be developed with some one else’s land.
There are various practices followed.
For example,one such arrangement is called 60:40 method.
Here the builder does not do any investment in plot but has to bear entire construction cost. Out of the final property developed, he has to allot 40% of the total built up to the land lord. Land lord  may either do the marketing of this 40% property himself or through the builder .

Sometimes the builder may agree to pay the cash equivalent of 40% of the property to the landlord at the prevailing market rate.

3.Take the right people to plan :
Third decision is the appointment of Architect
The architect is appointed usually  through previous association or  references obtained within group.

For some , this selection  is very simple, an architect who can give maximum yield on the given plot is considered eligible.

( Maximum built up area per sqft. of land)
Some builders consider the overall planning, uniqueness of design etc vital attributes in architect’s selection.
And of course the crucial criterion is the professional charges of the architect.

4.Package deal includes RCC designs?
Another decision is whether to appoint RCC consultant separately ?
Various options exist:
1. Architect himself is also the RCC designer.
2. Architect has a  RCC designer working with him or for him .
3. Architect recommends a RCC designer.
4. Architect leaves the selection of RCC designer to the builder.

In the cases 1,2 & 3 builder has a one point  dealing with the architect who gets all RCC drawings done from his consultant.

5.Who will get the approvals?
This is regarding the permission to build [ municipality approvals]  to be obtained  from the competent authorities, prior to beginning the construction.

The options are :

1. Architect shall himself liaise with the authorities and shall get the corporation approvals.
2. Architect shall only give the drawings. The builder needs to liaise with the authorities to get the corporation approvals.

3. Builder appoints a Liaison Architect who just gets permissions & approvals.

6.Who shall fight for you in Court of Law ?

This decision is related to the appointment of the Legal consultant who shall guide the builder through any legal disputes arising anytime during the acquisition of land up to handing over of the property to the customers and even beyond.

7.The Supervision :
This decision is related to how the construction is going to be supervised for Quality ,Quantity and delivery ?

There are several options :

1.Builder deploys his own employees for supervision.

2.Builder appoints PMC [ project Management consultant ] for supervision.

3. An experienced engineer is given the contract of entire supervision on % basis.

Summary :

The real success of the construction project ,like every other venture depends upon the formation of an effective team.

It is prudential to spend enough time and diligence to hand pick the team members. 

Better to aim for a long term association .