Construction

Talking of RMC than the designation Mix is certified on the supply challan. Further in case of doubt you can seek copy of the design mix formula followed. As regards slump test it is simply done to check the workability so as to ensure that delay in supply has not stiffened it which can create problems of flow into moulds. Strength is known after 7/8 days of casting which you can randomly do @45 cum of a lot.

(FYI : PPC is environment friendly as it consists fly ash in some specific percentages by parts, which is a waste product of burnt coal, usually collected from thermal power plants)

OPC (m53) attains strength in a shorter time, while PPC (m43) takes longer.
OPC therefore dries more quickly, but produces more heat during chemical reaction during which it gains strength, as compared to PPC
Faster is the drying process, more is the risk of cracking of cement, and therefore it need more care and more amount of water for curing in a lesser time.
PPC on the other hand can attain strength equal to OPC, but takes a longer time.

For a building slab, PPC is more widely used since it requires less care.
The strength depends on design mix (the water cement and aggregate ratio) more than type of cement.

so essentially, If you need construction to take place faster and have means for good curing, you may use OPC.
But if you need better quality and strength in less effort, use PPC.

It still depends on the structure’s design requirements and a structural designer’s advice is to be followed.

Hope this helps, but do consult an engineer before using any type of cement.
Building construction is a responsible job and needs to be done safely and one must adhere to engineer’s specifications.

What does FLOOR AREA RATIO mean:

FAR is a technical term used in Urban Planning that determines the total built-up space of the building on a plot of land. Generally, the FAR of the City or the Area is fixed by the government, based on various parameters like infrastructure, population or population growth. These you will understand once you are going through this issue.

So by Definition FLOOR AREA RATIO (FAR) is the ratio of BUILDING’S TOTAL COVERED AREA to THE SIZE OF THE PLOT on which it is built.

BUILDING’S TOTAL COVERED AREA is the Gross Floor Area.

Formula for FAR

FAR = TOTAL COVERED AREA (ALL FLOORS)/ AREA OF PLOT.

For e.f. If there are 4 Floors and each Floor is of 5000 Sq feet, then the Total Covered Area of all the Floors is 20000 Sq Feet and the size of the plot is 10000 Sq Feet, then FAR = 20000/10000 = 2. In some areas it is mentioned as % i,e, 200% or somewhere it is mentioned simply 200. So if it is 200 then it means the FAR of the City or Area is 2, meaning one is authorized to build up the covered area 2 times to that of the plot area.

But Generally FAR is fixed by the government, for particular City or Area and the FAR can be used to calculate the Total Covered Area that is built on a plot of land.

NOTE: There is one more term FLOOR SPACE INDEX i.e. FSI. The meaning of FAR and FSI is the same. There is a difference of only denoting these two. FAR is always mentioned in percentage. For e.g. the FAR of any City / Area is 200% then the FSI of the same City / Area will be denoted as 2.0.

Let us understand with the help of an illustration as in the image below:

For e.g. the total Plot Area is 10000 Sq feet

CASE 1: If FAR of a place is 0.5, then the total area to be built up is allowed only 5000 sq feet.

OPTION A: One can construct in 50% of the plot area, only one floor of 5000 sq feet. So FAR = 5000/10000=0.5

OPTION B : One can construct in 25% 2 Stories of 2500 sq feet of each. So FAR = (2X2500)/10000=5000/10000 = 0.5

CASE 2: If FAR of a place is 1.0, then the total area to be built up is allowed only 10000 sq feet.

OPTION A: One can construct in 100% of the plot area, only one floor of 10000 sq feet. So FAR = 10000/10000=1.0

OPTION B : One can construct in 50% of the plot area ,2 Stories floor of 5000 sq feet. So FAR = (5000 X 2) /10000 = 10000/10000=1.0

OPTION C : One can construct in 25% 4 stories of 2500 sq feet of each. So FAR = (2500 X 4) /10000=10000/10000 = 1.0

CASE 3: If FAR of a place is 2.0, then the total area to be built up is allowed only 20000 sq feet.

OPTION A : One can construct in 100% of the plot area ,2 Stories of 10000 sq feet each. So FAR = (10000 X 2 )/10000 = 20000/10000=2.0

OPTION B : One can construct in 50% of the plot area ,4 Stories floor of 5000 sq feet. So FAR = (5000 X 4) /10000 = 20000/10000=2.0

OPTION C : One can construct in 25% 8 stories of 2500 sq feet of each. So FAR = (2500 X 8) /10000=20000/10000 = 1.0

So if you know the FAR, you can calculate the total covered area that can be built on the plot.

How much open area you have to leave or how much area can be built up depends on the zoning and planning regulations also. For e.g. how much area to be left for:

• Setback.
• Parking
• Ground Coverage or Maximum Ground Coverage.
• Height Restrictions

FACTORS URBAN DEVELOPMENT AUTHORITY CONSIDER WHILE DECIDING FAR:

• The current population of the City / Area: When the population of the City / Area is high, the FAR is also high, it means the government is intending for Vertical Development as compared to the spread-out development,
• Population Growth: If the population growth rate is high, then also the FAR of the City / Area is high
• Infrastructure: Infrastructure also plays a key role while deciding the FAR of the City / Area. If Infrastructure is low then FAR will be kept low otherwise there will be pressure on infrastructural facilities viz, water, power supply, transport etc. If Infrastructure of the City / Area is already high and developed by the government relative to population density, then FAR can be kept at a higher level by the Authorities.

Note: If in the City / Area, the infrastructure is low but the population is growing at a faster rate, then the government has to increase the infrastructure and FAR has to be kept higher to accommodate the high growing population.

So when FAR increases the Population Density of the City / Area increases.

IMPACT OF HIGH FAR:

• Higher Population Density
• Stress on Infrastructure
• Better Profitability for Developers
• High Land Value
• Better Walkability

IMPACT OF LOW FAR:

• Lower Population Density.
• Better Per Capita Infrastructure
• Reduced Profitability for the Developers.
• Low Land Prices.
• Long Travel Distances