Building Construction

Column Layout for a Residence | Civil Engineering

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Column Layout for a residence using the Thumb rules | Building Construction

In my earlier article, we discussed three important thumb rules that are to be followed while making a column layout for any building. They are as follows:

  1. Size of the Columns
  2. Distance between the columns
  3. Alignment of Columns

In this article, we will see an example of a residence of which column layout is done keeping the above three thumb rules in mind.

Column Layout for a residence

The residential villa comprises of 1 and half floors. Initially, the column size 9″x12″ had been used with the use of M15 grade of concrete. The builder wanted to save on his budget by making the columns smaller in size. That is why, the columns in the Floor plans below are 9″x9″ in size but the Engineer made sure that M20 grade of concrete would be used for Columns.

Column Layout for a Ground Floor
Column Layout for a Ground Floor

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Septic Tank Design for an Office Complex

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Septic Tank Design Calculations | Building Construction

In the previous article, we discussed in detail the calculations that are to be carried out for the design of a Septic Tank for 3bhk, 2bhk and 1bhk homes.

In this article, we will move forward with our discussion on the Septic Tank calculations for an Office Complex.

First question that is likely to occur to your mind would be, “How are Septic Tank Design calculations for an Office Complex different from that of a Residence?”

Let us first answer this question before we move forward with the calculations.

Residences are structures which are occupied with families living, eating and sleeping there. Let’s take an example of a person who regularly goes to an office for his job.

Let’s have a look at his Daily schedule:

  • He wakes up in the morning.
  • Takes a bath, uses a toilet.
  • Has his breakfast after which he washes his hands. Apart from him using the services in the house, his family members also use the same.
  • He leaves for his office. After he reaches the office, he wouldn’t take bath which consumes the maximum amount of water which turns into sewage water after use.
  • His usage of toilet and bathroom would be minimum. Hence, it is important to understand the logic behind the Septic tank calculations.

Calculations for an Office Complex with 8000 employees

As per thumb rule;

Quantity of sewage to be considered for an Office Complex is to be calculated on the basis of the capacity of the Office.

Now, we are calculating the Volume for the Septic Tank required for an Office Complex with 8000 employees.

Hence, quantity of sewage to be considered per person should not be less than 20 gallons.

Office Complex = 8000 persons

Total quantity of sewage = 8000*20 = 1,60,000 gallons

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Thumb rules for designing a Column layout | Civil Engineering

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Guidelines to be followed for making a column layout

In this article, we will go through the essential thumb rules to be followed for giving a column layout. Of-course columns have to be designed in accordance to the total forces acting on the structure, but apart from that, it is essential for every Civil engineer and Architect to remember a few thumb rules so that they are prevented from making mistakes.

You can hire me for your structural design need. Contact me.

Three thumb rules to be followed are as follows:

  1. Size of the Columns
  2. Distance between Columns
  3. Alignment of columns

Minimum Size of RCC columns

The size of the columns depends on the total load on the columns. There are axial loads and lateral loads. Large beam spans induce bending moment not only in the beams, but also in columns which are pulled by the stresses in the beams. It is important to use advanced structural design software like ETabs or Staad pro. I highly recommend every structural designer learn these software. The thumb rules are for general designing in very small projects.

For this general thumb rule, we will assume a structure of G+1 floors high, using standard 6″ walls.

Minimum size of an RCC column should not be less than 9” x 12” (225mm x 300mm) with 4 bars of 12 MM Fe415 Steel.

These days the minimum I use in my projects is 9″ x 12″ (225 mm x 300mm) with 6 bars of 12 MM Fe500 steel. You can never go wrong with strong columns. I also recommend use of M20 grade concrete for the structure (ratio 1 part Cement : 1.5 parts Sand : 3 parts Aggregate with 0.5 parts water by volume). I recommend use of 8 MM stirrups at a distance of 150 MM center to center throughout the length of column.

This setup of 9″ x 12″ RCC columns is safe for G+1 Floors. There are a lot of other considerations, but this is just a thumb rule.

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RCC Building Design and Construction | Structural Design

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Step by step procedure to RCC building design | Design of RCC Structures

A building is composed of various structural components such as Foundations, Plinth beams, Columns, Beams, Slab, Staircase, Doors and Windows.

RCC Building Design
RCC Building Design

Design of Foundation | RCC Building Design

Foundation design is the structural component from where the RCC design is initiated. The foundation design guide discussed earlier includes in detail the design procedure for isolated column footing. Column footing is the most commonly used type of foundation. It serves a variety of different buildings.

  • Design of Foundation – the most commonly used foundation is Column footing.
  • Calculation of loads in Foundation Design Calculation of loads is very important for the purpose of structural design. This article outlines the thumb rules for the calculation of various loads in foundation design.
  • Types of Foundations This is a generic article on different types of foundations. It covers some commonly used shallow foundations and also explains pressure distribution under a foundation.

Design of Beams | RCC Building Design

Beams are mainly classified into two types:

  1. Doubly reinforced beam (most commonly used in RCC Construction)
  2. Singly reinforced beam
    A series of articles have been written for the design of Singly reinforced sections. The articles include basic definitions and formulas, understanding stresses and modular ratios, assumptions for singly reinforced sections, Design method 1, Design method 2, Moment of resistance and a number of solved numerical examples.

Design of Columns | RCC Building Design

Design of RCC columns

The article discusses the classification criteria for a column,  and design of different types of reinforcements for columns which include longitudinal, transverse and helical reinforcements.

Thumb rules for designing a Column Layout

The articles important thumb rules to be followed for column layout design. Three important thumb rules have been discussed.

  1. Size of the Columns
  2. Distance between Columns
  3. Alignment of columns

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Failures in Buildings | Important Construction Materials

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Defects in Buildings | Building Materials used in Construction

In my previous article, we began with a discussion on Building Materials used for Construction. We have already discussed the two major building materials such as Sand and Mud. Now we will go on and discuss the role of water, Cement and Cement Mortar in Construction.

Water in Construction

Salt free water should be used on the construction site for the mixing of cement. If salty water is used in the construction, it will result in formation of cracks in the building.

For example: Vishakhapatnam in Andhra Pradesh, India has brine water below 100’. That is why, the bore cannot be dug to more than 80’ feet for water to be used on the construction site.

Cement in Construction

There are various grades of cement available for the purpose of construction.

For example: M15, M20, M25 etc

The grade of cement to be used for construction is decided on the basis of the kind of construction and the structural design.

Cement is always used along with steel, that is RCC (Reinforced Cement Concrete) construction. Only cement cannot be used because it develops cracks.

Grooves are made over the layer of cement mortar.

For example: When cement flooring is done, a thin layer of cement is laid and grooves are made on the cement layer to prevent cracks.

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Repair of cracks in the RCC Staircase | Building Construction

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What would you do in case of a RCC staircase having cracks?

The development of cracks occurring in RCC staircase is one of the major problems to deal with in RCC construction.

Before we go to the ultimate solution of the repair of cracks in a staircase, I would want all the students to know that, “Design in a way that you would never have to look for solutions”.

This is an important matter. The graver the problem, the harsher and shorter the solution is….

Basic elements of Staircase
Basic elements of Staircase

Earlier, in one of my article, I have explained the “Design of RCC Staircase”. Please do go through before designing….

RCC staircase cracks

There are two types of cracks, they are;

  1. Minor cracks or surface cracks
  2. Major cracks or structural Cracks

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Factors causing damage to the building | Failures in Buildings

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Factors causing damage to the building | Building Construction

Major damage to the building is usually caused by the natural calamities. But there are various factors that can cause damage to the buildings.

Some of them are as follows:

  • Erosion
  • Earthquake
  • Natural Calamities
  • Violence
  • Fire
  • Lack of maintenance

Cracks in a Building at San Francisco
Cracks in a Building at San Francisco

The damage incurred to the building is usually in the form of major and minor cracks. Major cracks could be structural cracks which cause immense damage to the structure. Earlier, I wrote two articles on the subject “Cracks in Buildings“. The cracks are classified depending on the amount of damage they cause to the structure.

Physical inspections to be done in a building

After the construction of any building, periodical inspections of physical components of the building are to be carried out.  Physical inspections help us in keeping a check on the damage or wear and tear caused to the structure. Inspection is important so that we identify the problem and repair it before it gets unrepairable.

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Tips to Building Construction | Repairing an Antique door and a Cracked brick wall

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Repairing an Old Rotting Antique Door and Repairing a 14″ crack brick wall | Building Construction

In this article, I have mentioned two cases where the remedy for their repair is briefly explained. This sounds very easy but I am sure it will be of good help to all the Architecture and Civil Engineering students…

How would you restore an old rotting antique door?

The dimensions of the antique door are 7’x4’.

The rotting part of the door is to be cut carefully.

And the cut part of the door is replaced by the similar variety of wood.

After replacing the wood, give a similar finish to the door.

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Tips of Building Construction | Civil Engineering

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Method of Luppm Finish and Cleaning of pinhead glass | Building Construction

This is a simple article which deals with two different topics explained in a very brief manner. I hope it will be helpful to the students of architecture and Engineering….

How would you clean a 3mm pinhead glass?

Usually, a chemical called as “aerosols” are used for cleaning 3mm pinhead glass.

The welded design on the pinhead glass can be made plain with the help of some chemical powder and then rubbing the glass with a sandpaper.

How would you luppm finish on an already painted wall?

Oil paint + whiting powder= luppm paste is made.

The paint and plaster of the already painted wall is scraped out.

Then the wall is made rough by chiselling or the wall is brushed by a “wire brush” that makes the wall rough.

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Tests for Fresh Concrete | Building Construction

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Tests for Concrete to be performed on site

Tests are held at 28 days, 7 days and 3 days. Constituent of mix should be such that concrete can be transported, placed and finished easily without segregation.

  • Workability – it is a property of fresh concrete and affects the finished product as it affects compaction.
  • Need for workability – Imparted by the amount of useful internal work necessary to provide full compaction.

Tests for Fresh Concrete
Tests for Fresh Concrete

Optimum water varies for different methods of compaction

  • i.e., more water – hand compaction – lower density
  • less water – mechanized compaction – higher density

If we add more water, the workability may increase may increase but core has more voids

  • 5% of more voids – reduces strength by 30%
  • 2% of more voids – reduces strength by 10%

The voids result due to –

The entrapped air voids are caused by grading of fine aggregate.

Excess water evaporating later excess – (water) voids are due to increase in workability

Aim should be to have maximum density – therefore for maximum compaction, you will have to have optimum water cement ratio, at which both the type voids are at minimum.

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