## Unit Conversion

In Civil Engineering it may be on Construction Site while Executing any project or doing calculation in studies or in structural engineering while designing a structures or it may be in any field, it becomes problem when you are not familiar with the basics units. So In this short blog you will be able to convert any units to other unit without memorizing each one. If you know about the most basics unit then you can convert and manipulate bigger units and calculation by just using these concepts.

One thing to remember is if you convert a bigger unit to Smaller one the you have to Multiply with equivalent value and from smaller to bigger one then divide the equivalent value. The following example will clear your concepts.

### (1) Linear or One Dimensional (1D) Unit

###### Length, Distance, Displacement

1st you should know about one linear or dimensional units and these are the basics to convert to any others units if 2D (Area) & 3D(Volume) e.g foot, meters and inches ect if you don’t know about these basics then you can learn it by using a measuring tape (inchi tap). These are basics then you can convert bigger linear units e.g Km, miles etc. You can see here the feets, inches and soot (soother) on the upper part and meters, cm and mm on the lower part horizontally.

### (2) Two Dimensional(2D) Units

###### Area, surface area, cross-sectional area

So Area is a 2 Dimensional quantity and you can find these units by just squaring of the one dimensional or linear units e.g taking square of m you will got m2 and the same way all other units. It can convert from MKS (meter, kilogram,second) to FPS (Foot,pound Second).

(a)Example: Convert=>5m2 to ft3 => 20m2 = 20 (1*3.28)2 =20*10.76 ft2= 215.2ft2(here using only linear units and converted from bigger to smaller that’s why multiplied)

(b)Example: Convert=>50ft2 => m2 = 50* (1/3.28)2 =50*0.0929 ft2= 4.645m2 (here using only linear units and converted from smaller to bigger units that’s why divide)

### (3) Three Dimensional (3D)

###### Volume

Volume is a Three Dimensional Unit and you received that unit by taking cube of 1d units e.g if you take cube of ft then it will become ft3 which is 3d unit. It can be converted any 3d units of MKS(meter, kilogram, second) to FPS(foot,pound, second) with the help of linear units without memorize the exact relation between them.

(b)Example: Convert=> 5m3 to ft3 => 5m3 = 5 (1*3.28)3 =5*35.3 ft3=176.4ft3 (here using only linear units and converted from bigger to smaller that’s why multiplied )

(b)Example: Convert=>40ft3 => m3 = 40* (1/3.28)2 =40*0.028 ft3= 1.12m2 (here using only linear units and converted from smaller to bigger units that’s why divide)

Force,weight and load are same terms used in Civil Engineering and general units used for that is Newton(N), Kg, Pound (lb), KN, Kip(kilo-pound).

If you know about the most basics one e.g 1 Kg=10 N, 1 kg= 2.205 lb then you can convert any units with the help of these tow.

Examples: Convert=>

• 10 kg=> N=> 10 kg= 10 *10 N = 100 N (multiplied; Bigger=>Smaller)
• 200 lb=>KN=> suppose here we don’t know about the lb and KN relation then 1st we will convert lb to know unit that we know. So taking help from “1 kg = 10 N” & “1 kg= 2.205 lb” , 1 lb= (1/2.205) kg= 0.4535 kg , now convert the 0.4535kg into N ; 0.4535*10 N= 4.535N Now convert it to KN(divide by 1000); 0.004535 KN. So 1 lb=0.004535 KN. Now 200 lb= 200 *0.004535 KN = 0.91 KN.

The same way you can convert things without any single relations known.

### (5) Stresses (Force/Area) and Densities (Force/Volume) and Moment/Torque (Force *Distance0

So if you have learnt about how to convert forces and 1d(length), 2D(area), 3d(Volume) units then you can easily convert the units of stresses, Densities and Moments/ torques etc.

So we will solve one example for stresses

Examples: Convert=> 1Mpa to Psi

Mpa= N/mm2 and Psi= lb/in2 ; 1 N/mm2 ; So suppose here I don’t know about lb and N relation then taking help of know relations e.g 1 kg = 10 N=> 1 N= 0.1 Kg now replace the kg by pound (lb) because we know that relation; 1 N= 0.1 ( 2.205 lb)=> 1N= 0.2205 lb and the same way convert mm2 to in2 => suppose we don’t know the relations between mm to in then; 1mm2= (1/1000)2 = 1o-6 m2; converted into meters because we know the relation between meter to ft; 10-6 (3.28)2 ft2 = 0.00001076 ft2 now convert that feets to inches; 0.00001076*(12)2 in2= 0.001549 in2 .

Now put the values of 1 N= 0.2205 lb and 1mm2= 0.001549 ; 1 N/mm2(MPa)= 0.2205 lb/0.001549 in2 (Psi)=> 1 N/mm2=143 Psi but exactly it is equal to 145 Psi as I put values approximately.

so from the above example you may have cleared that only know the basics concepts you can derive any units.

Watch the Video given below I have discussed it briefly;

==========Thank You==========

## Nominal Vs Mix Design of Concrete

### (1) Nominal Mix of Concrete

You may have noticed that normally on construction site, the mix ratio of concrete has been already mention in construction drawings. So you have to follow that ratio of concrete. That concrete will give you a concrete strength of ordinary strength normally from M5(1:5:10) to M25(1:1:2). The magnitude mention with the letter M mean the Compressive strength of concrete which in in N/mm2 or Megapascal(Mpa). You can see some Nominal Mix ratios in the table given below.

So this is about the nominal mix when you have to follow the already fix ratios regardless of the material specific properties. This is normally used for residential or other commercial structures where there is no need of high strength concrete.

### (2) Design Mix Ratio for Concrete

So the Design mix of concrete is done for high strength of concrete. When the strength requirements beyond M25 (25 Mpa) strength of concrete and when the structures strength is the primary priority then you have to go for Mix Design of concrete.

In Mix Design of Concrete you have to check every material (Aggregates, Water, Admixtures etc) properties that you have to use in your concrete mix and upon some trial you have got the desired strength with some mix ratios. So that Mix proportion of concrete ingredients should be noted with the respective strength. For this you have to bring all the samples of your materials (Aggregates, fine Aggregates, water etc) ingredients to the Mix Ratio Laboratory of your specific area from where you considered to use the concrete ingredients Source. If you want to change the source of the concrete ingredients during construction, then again you to go for mix design. Then that will be your Design Mix ratio for concrete that you have to follow for that specific structures and specific projects. Some Examples of Mix Design ratios or given in the table below but you cannot follow it directly on your site and you to do your own MIX Design for the Concrete ingredients that you have to use in your project. So the values given in table for mix design is M30 to M70.

Thank You if you have still any doubts, you can ask in comment.

## Dampness

###### Definition

The access or penetration of moisture contents inside a building through its walls. floors on roof is known as dampness.

Dampness is not only injurious to buildings but it affects adversely the health of their inhabitants. it becomes, therefore,essential to know the causes of dampness and methods of its prevention so that the buildings can be constructed damp-proof.

## Effects of Dampness

Following are the common ill or harmful effects of Dampness in a Building.

• It causes dry rot to the wooden members provided in the building.
• It cause corrosion of metals used in the construction of a building.
• It causes peeling off & removal of the plaster.
• It causes the paints to get blistered & bleached, and the surface thus gets disfigured.
• It causes floors of the building to remain ugly since they cannot be cleaned well.
• Carpet, if used on floor of a damped building, gets destroyed earlier.
• All electric installations get deteriorated.
• It causes efflorescence which affects the exposed surface of the brickwork to disintegrate and fall to powder.
• It reduces the life of the structure as a whole.
• It causes unhygienic conditions for the occupants of the building and affects adversely their health.

## Causes of Dampness

• Rain penetration
• Drainabililty of Soil
• Defective Orientation
• Moisture entrapped during construction
• Defective Materials
• Defective Construction
• Moisture which originates in the building itself
• Level of Site
• Climatic Conditions.

## Required Dimensions of Water Tank

After reading this article you will be able to find out all the dimensions of water tank as per requirements.

So lets assume that Volume of Water required for one person per day is 135 liters

## Details

• Drinking = 5 liters
• Cooking = 5 liters
• Bathing and Toilet = 85 liters
• House Cleaning = 10 liters
• Cloth Washing = 30 liters

Total Water 135 liters per day/capita

Q: Design the Water Tank for 12 members of family.

So lets find out all the dimensions of the water tank to fulfill all the requirements.

Total water requirement is = 12 x 135 =1620 liters per day required

We Know that

Density of water is 1 cum = 1000 liters

1 liter= 1/1000 cum

1 liter = 0.001 cum

Our Water Requirement is 1620 liters

So, 1620 x 0.001 cum = 1.62 cum (Volume of water)

Assume Height of water tank = 1.5 m

Find Area of Tank = 1.62/1.5 =1.08 sqm

To find the Length and Width of Water tank we have to take the Square Root of the Area

After taking the Square root you will find = 1.039

## Dimension of the Water Tank

• Height = 1.5 m
• Length = 1.039 m
• Width = 1.039 m

## 1)Fast Drying Concrete Cracks

It occures due to fast drying of water from concrete due to evaporation.

## 2) Over weighted Concrete Cracks

This cracks occure due to Overloaded Structure or heavy weight on structure and it generally leads to the total failure of that structure.

## 3)Settling Cracks

This type of cracks occures due to settlment of soil or any other subsurface under that concrete.

## 4)Plastic Shrinkage Cracks

This type of cracks occure due to excess of water in concrete mainly on its surface during concreting.

## 5)Heaving Cracks

This type of Cracks occures due freezing and thawing cycle in concrete.

## 6) Expansion Cracks

It occures due expansion of concrete in hot season.

## Anti-Termite Treatments

The treatments which make a building and its contents termite, proof are known as anti-termite treatments.

### Purposes of Anti-termite Treatments

• To prevent the possible invasion of subterranean termites from the ground to the building and its contents through external entry or internal attack from under floors.
• To eliminate the existing effect of dry-wood termites and subterranean termites on wood work, cellulosic material and other contents of a building and to make them resistant to termite attack for future.

### Types of Anti-termite Treatments

#### 1)PRE-CONSTRUCTIONAL TREATMENTS

The anti-termite treatment measures adopted at the time of construction of a building are known as pre-constructional treatments. The soil adjacent or under the building are treated before the construction of building with suitable insecticides or treating solution.

#### 2)CONSTRUCTIONAL TREATMENT

The anti-termite treatment measures employed during the construction of building are known as constructional treatments. This provide in the form of masonry groove or termite shield or string course and cement concrete apron floor, solid type floor, etc during construction.

#### 3)POST-CONSTRUCTION TREATMENTS

The anti-termite treatment measures adopted in existing building are known as Post-Constructional Treatments. It is the anti-termite treatment consists of treating the wood work and wooden based materials of an existing building with a suitable chemical termiticide solution.

## Methods of Preventing Dampness

Dampness Prevention

• By Providing a Damp-Prof-Course (DPC)

The continuous layer of an impervious material, which is provided in between the source of dampness and part of the structure is called a Damp-Proof Course.The function of providing damp proof course is to prevent dampness and it is laid either horizontally or vertically. Horizontal D.P.C is generally laid 150 to 200 mm above the ground level on the external walls and at plinth level in case of internal walls of a building. While Vertical D.P.C is provided to connect the horizontal D.P.C in the external walls with the floor level to check the flow of moisture from the underside of a floor into the walls.

• By Surface Treatment

This method consists in painting the exposed surface of the wall with a water repellant paint. Material to be used for painting the wall surface must be durable and effective to check the absorption of moisture by the wall.

• By Integral Water-Proof Construction

This method consists of adding certain compound in the mortar or concrete to make it more dense by filling the pores through chemical action or mechanical effect. If 5% sunlight soap is added in the water to be used for preparing the mortar, the pores get clogged and a coating of water repellant substance sticks to the wall surface which makes it sufficiently Damp-Proof.

• By Special Devices

Dampness can be prevented by using some special devices which are given below:

1. By constructing the external walls of sufficient thickness.
2. By using the bricks of good quality for constructing the external walls.
3. By building the walls in rich cement mortar.
4. By providing string courses and cornices.
5. By fixing the down water pipes in sufficient number so that water may not leak through the junction of wall and the roof.

## Building Planning

The basic principles of residential building are discussed bellow:

• Floor Space Index (F.S.I): The F.S.I is the ratio of the total built-up area including walls to the area of land on which the building is to be constructed. It is the measured to check the density of population. The margin on road side shall be 4.5 m.
• Plinth Height: The plinth height shall be 450 mm above plot level or road level whichever is higher and also depends upon topography of the locality.
• D.P.C: It should be 40 mm thick of cement Concrete (1:2:4) with two coats of hot bitumen covered it.
• Height of Roof: The height of roof shall be 2.7 to 3 m maximum and for bathroom it shall be 2.1m minimum.
• Area of Doors, Windows and Ventilators: Generally the area of doors and windows shall be more than 1/7th of the floor area of rooms of a residential buildings.
• Stair Case: Stair Case max. area shall be 12m2. The pitch shall be 30° to 45°. Each flight shall min. 3 steps and max. 12 steps. Minimum width of stair shall be 900 mm.
• Lift: It should be provided in buildings having more than three floors excluding ground floor.
• Sock Pit and Septic Tank: These shall be provided for each building where there is no provision of sewer at present.
• Height of Compound Wall: The maximum height of compound wall on road side shall not be more than 1.5 m and on other side it should be 1.8 m.
• Open Space: The open space shall be 1.8 m (min) and 3 m (max) for either side when the height of building is less than 10 m.
• Distance from the Building line of the street: Minimum 3 m in any case.

### Factors Affecting Building Planning

• Arrangements of the doors and windows to meet the requirements of the inhabitants.
• Privacy of the buildings from neighboring buildings and also within the buildings froom one room to other.
• Arrangements of rooms like kitchen should be near to dinning room and away from living rooms.
• Good aesthetic view of the Building from outside.
• Maximum space should be utilized in a square shape.
• All the room should be well furnished and designed.
• Sufficient Sanitation of the building keeping in view while it’s planning.
• The use must be flexible in order to use the rooms for any purposes according to the inhabitant requirements.
•  Free circulation should provide to the inhabitants from one room to another.
• Future Expansion of the building keep in mind while it’s planning.
• The building should be stable in any kind of forces apply on it.
• The proposed building should provide comfort and convenience.