PLINTH AREA AND CARPET AREA OF A BUILDING.

PLINTH AREA : Plinth area of a building is the built up covered area of the building measured at any floor level(i.e. floor level at any storey). It is calculated by measuring the external dimension of the building excluding the plinth offsets, courtyard, open spaces, cantilevered porches,  balconies, loft(space directly below the roof covering large space similar to attic, attic refer to whole floor below roof but loft may not). But the supported (other than cantilevered) porches are included in the plinth area.
Sunshade, cornices are not taken into account in plinth area.
CARPET AREA: It is the area excluding the areas of interior and exterior walls and columns from plinth area.
     

       In simple words, plinth area is the total area upon which the structure is built up and the carpet area is the area upon which the carpet can be laid. In this sense carpet area is always less than plinth area for a building.

Civil 2nd, 3rd, 4th year syllabus for IOE, Tribhuwan University

https://drive.google.com/drive/folders/0B8ARLstjHaC9ejhvUEVpQ2VWeEE

Civil and Mechanical first year syllabus for IOE, T.U. Nepal

https://drive.google.com/drive/my-drive

Characteristics strength,Grade of concrete and Nominal mixes

Characteristics strength:It is the minimum strength of concrete for which the designer has reasonable assurance. Mathematically it the compressive strength of material above which 95 percent of the test result of the 15 cm cube (after 28 days) are expected to exceed.
Grade of concrete: it is the number which denotes the characteristics strength expressed in MPa. The number is usually preceded by the letter M which refers to mix.
      Nominal mix is the fixed proportion of cement:sand:coarse aggregate(by mass or by volume).It is the approximation of grade of concrete and their nominal mix.The actual proportion for a grade of concrete can only be known from mix design method.Some grade of concrete and their respective nominal mixes are given below:
M10   -   1:3:6
M15  -    1:2:4
M20  -     1:1.5:3
M25  -     1:1:2

SOME TERMS RELATED TO MINERALS, ROCKS, STONES,CONCRETE

Cleavage: tendency of a mineral to split along a certain plane parallel to crystal face.

Hardness: it is the resistance offered to abrasion by a mineral. It is expressed in Moh’s scale. To know the hardness of the mineral, it is stretched with a series of substance of known hardness which is given below:

Talc-1   

Gypsum-2

Calcite-3

Fluorite-4

Apatite-5

Orthoclase-6

Quartz-7

Topaz-8

Sapphire,corundum-9

Diamond-10

Toughness: it measures the impact that a mineral can withstand.

Streak:It is defined as the colour of mineral in the powered form.

Lusture: it is the shine on the surface of a mineral and its appearance under reflected light.

Seasoning: it is the process of drying quarry sap. Quarry sap is the Freshly quarried stones which contain certain amount of moisture.

Dressing: it is the process of giving definite and regular shape with smooth faces to stone.

Weathering: It is the effect of atmospheric conditions on the stones, rocks. The atmospheric conditions refers to wind, rain, temperature, moisture content etc.

Texture:the feel, appearance, or consistency of a surface or a substance is called texture. It may be smooth, rough, slimy, fuzzy, honeycomb etc.

Fatigue:weakness in metal or concrete caused by repeated variation of load.

Creep:it is the permanent deformation under the influence of long term mechanical load. it can occur due to exposure with long term high stress, the stress may be below the yield strength of material.

Honeycomb: it represents the rough pitted surface resulting from incomplete filling of concrete against formwork or it represents voids in concrete resulting from incomplete filling of voids among the particles of coarse aggregate. it is caused due to the use of stiff concrete or due to insufficient vibration.

Angularity Number Test of Aggregate

It is a non- destructive quality test for aggregate. It is the test about the shape of the aggregate. It gives the qualitative representation of the shape of the aggregate. It is measured in terms of percentage of voids in excess of voids in perfectly rounded aggregate(33%). The more angular the aggregate is, the more is the Angularity number.The normal aggregate suitable for making concrete have angularity number lying between 0 and 10. The rounded aggregate has Angularity Number zero.
When rounded aggregate is filled in a vessel, it leaves about 33% void in it. If a well compacted Aggregate in the same vessel of rounded aggregate leaves 43% voids then its Angularity Number is 10. This test is not applied for the aggregates which gets crushed during compaction of this test.

Apparatus required:

• Metal cylinder of 3 litre capacity.
• Metal scoop
• Tamping rod.  

Procedure: 

• The test sample of the aggregate is sieved and specified size ranges such as 16-20 mm, are used for the test.
• The sample is then filled in the metal cylinder in three layers. Each layer is tamped 100 times with tamping rod before the next layer is put.
• The weight of the aggregate filled in the cylinder is determined. And then after emptying it, it is filled with water and weight of the water is also determined.

Then use the following formula to find the Angularity number:
Angularity Number= 67 - W*100/w*G
W=Aggregate weight filled in the cylinder.
w=Weight of the water filled in the cylinder.
G= Sp. gr. of aggregate.




 Fig. Metal scoop.

Balancing Canal depth

Balancing Canal depth:

Balancing canal depth comes when the canal is in partially embankment and partially in cutting.It is the depth of the canal(H) which gives equal amount of filling(i.e earth required for formation of Banks) and cutting(i.e earth from digging). For a given cross-section of a canal, it has only one balancing depth. For this depth the canal sectional will be economical.
B= Bed width.

b1,b2= width of embankment of left and right side respectively.

d= excavation depth.

h= embankment height.
H=height of embankment from the bed of the canal.

    X- sectional area in cutting =Bd+sd²

     ^{X- sectional area in embankment =} (b1+b2)h+2s1 h²

^{For balancing depth,}

^{Area in cutting= Area in embankment.}

^or,  Bd+sd^{2  =} (b1+b2)h+2s1 h²

or, Bd+sd^2=(b1+b2)(H-d)+2s1(H-d)^2.

From this equation 'd' can be calculated.