Basic Setting Out of a Building

Well if you are a Civil engineer having a building plan in hand and not knowing what to do where to start this post will help you a bit.Yep i mean only a bit not much because i'm only discussing the very basics in this post.

Okie... first to begin with what is a setting out of a building?. We can simply answer to that question like this.Architects and other people who are dealing with the design of the structure gives us a plan.Its only a paper showing some lines , dimensions and levels etc.To add some value to that we can say them structural and architectural drawings.As a man responsible for the construction we need to give life to those plans in physical terms.In order to do that we need to locate the geometrical items of the building in correct places according to the drawings. This is the process known as the setting out of the building.

got it? .or confused??? ... alright here it is in old text book way..

Basic setting out of a building is the process of locating the positions of the structural parts of a building in geometrical construction.

Enough of introductions, back to the topic again.
So you have a plan in hand and a land to build.Where to start and how to start?

We need  a base line first.It is any geometrical boundary that we can find in the site.In some architectural drawings it is specially mentioned.If not contact your consultant and come to an agreement on what to chose as the base line.In simple two story or three story building construction we can simply choose a perimeter wall    or any permanent structure nearby.From that baseline we can start our work.We can start measuring distances from that .

Now choose a position as your 0.000 level.Most of the time it is mentioned in the drawings.If not discuss with your consultant and come to an agreement to avoid future disputes.Pay attention to flood level and natural water tables etc.. when selecting the level 0.000.

Now have a look at your drawings(plans).Select the biggest rectangle or the square that is on the drawing.

But why on earth do we need the biggest one? cant we start with the smallest one? NO. YOU NEED THE BIGGEST ONE .!!

Biggest Rectangle in Yellow 

The reason is that we do the setting out process in a method called "WHOLE TO PART". We start with the biggest and subdivide it to obtain the smaller ones.This method help us to eliminate the errors and introduce a way to crosscheck.

Remember the setting out work must always provide independent checks for better accuracy.

Main instruments involved in this process are Theodolite, Steel and Linen Tapes, Arrows, Wooden pegs, Wire nails and Nylon threads.

After establishing the base line, the main rectangle is set up using the pegs and theodolite. Arrows are used as temporary pegs and wooden pegs are driven for permanent pegs .90° angle is taken by the theodolite and Pythagoras rule is also commonly used for the process. When using the Pythagoras rule proper care must be paid to obtain the largest possible combination of triangles for higher accuracy. Steel tape must be used to measure long distances and it must be tightly stretched when taking the readings.

Wooden pegs atop by a wire nail are driven to establish the grid lines of the building. These pegs are driven at places such that they won’t be disturbed by field work etc. Usually they are driven with a distance of 1.5 meter from the grid line.

The diagonals of the main rectangle are checked to determine its accuracy. Accurately set up main rectangle is then subdivided to obtain the consisting gridlines. These are obtained by the using structural drawings, Theodolite and steel tape. Nylon threads are stretched between the pegs to obtain the gridlines when necessary.

Usually apart from the pegs depicting the main grid lines, pegs which show the 500mm off sets are also established during the setting out process to facilitate the construction that follows.

Autodesk-Architectural Desktop as a Power Tool in Project management reports

Autodesk-Architectural Desktop is widely used as a 3D modeling software in the construction industry, mainly for architectural purposes..

It is a user friendly software rich with a wide variety of modeling techniques that enables the user to model 3D structures complete with all the details..

This software can also be used as a project management tool in terms of presenting monthly or weekly progress of  the project in detail …

A user can create a model according to the structural drawings  and then  update it with the construction progress.. Different colors and layers  can be utilized to show different elements such as walls, columns ,bases etc. By switching these layers on and off  an individual assessment on the progress of the certain element can be easily obtained. Pictures of the construction process obtained in this manner are of great value in management reports such as monthly progress reports. These 3D pictures give a clear idea about the progress of the construction and enables an overall picture of the process than just looking at  a table ..

Following pictures are some example of the process…

Monthly progress: December

Site situation as at 1st December

Site progress as at 31^st December

Earth Fill     Column concrete   

Tie Beam    Base Concrete 

Random Rubble Masonry  

Base Concreting   45%  completed

Column Concreting

(i)Up to DPC Level 45%  completed

(ii)Above DPC Level 35% completed

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Tie Beams 45% completed

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Random Rubble Masonry

56% completed

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Earth fill      34% completed

Compressive Strength Tests for Concrete

1)    Cube Test

Compacting of Concrete Cubes

This is the conventional method of testing the compressive strength of concrete. This can be described as a “destructive” method of testing as casted concrete cubes are crushed to determine the compressive strength.

crushing of cubes

In this testing procedure concrete cubes are casted in a standard way such that they represent the batches of concrete used for concreting. The cubes are of the size 150x150x150mm and each cube is casted in three layers with specified compaction to each layer. Cubes are properly cured and crushed at the ages of 7, 28 etc. Three cubes are crushed at a time and their mean crushing strength is taken as the compressive strength of concrete.

2)    Impact Hammer Test

Impact Hammer Test

This is a test specially designed for non-destructive testing of concrete structures. Using this test large areas can be tested for compressive strength consuming less time and money. Possibility of determination of concrete quality between different sections is also an advantage of this test.

The testing is done by pressing a impact plunger against a solid surface of concrete. The maximum height of rebound is recorded and a rebound number is obtained according to the scale of Impact Hammer. This rebound number can then be converted in to compressive strength via conversion tables provided with the equipment. These conversion values vary with the angle of testing and therefore angular corrections should be applied when necessary.

3)    Ultrasonic Test.

Ultrasoinc Test

Ultrasonic test for concrete is a field test for quality control and inspection of concrete structures. It uses measurement of the speed of ultrasonic pulses through the concrete to correlate concrete strength to standard strength. Using this test we can identify non-homogeneous conditions in the structure such as honeycombs, voids, cracks and frozen concrete.

First the instrument is calibrated using a standard calibration bar and the receiving and the transmitting ends are coated with a thin uniform grease layer. The concrete surface is cleaned well to make it dust free and uniformly distributed grease layer is applied on the concrete surface as well. The transmitting and receiving ends of the apparatus is then placed on marked locations of the structure and the machine is turned on to get the reading. The test is repeated after switching the positions of the transmitting and receiving ends. Then obtained readings are compared with the standard values to arrive at a conclusion about the concrete quality.