Thumb rule for every civil Engineers

Thumb rule for every civil Engineers

Thumb rule Introductin

Thumb rules play a most important role during work in construction site. Thumb rules enable you to calculate idea using a simple maths formula and make smart conclusion whenever needed. Remember, Thumb rules is not give the accurate result, but you can use them for roughly results. There are many thumb rules which we apply in construction site.

more knowledge of civil engineeering vist civilengineersgyan.blogspot.com 

Thumb rule features 

thumb rule is an approximatly & comparing method in civil engineering. In thumb rules, The units are not the same when we compare to get the  possitive results.Here I am discussing the most frequently used Thumb rules on construction site.

Thumb-rule-for-every-civil-engineers

1-  Thumb rule in Steel in Rcc (Beams, Footings & Columns  ,slabs)

residential buildings steel quantity = 4.5 Kgs – 4.75 Kgs / Sq. Ft.

commercial building steel quantity=5.0 Kgs-5.50 Kgs/Sq. Ft.  

Structural Member Percentage of Steel

Slab - 1% of total volume of concrete

Beam- 2% of of total volume of concrete

Column- 2.5% of total volume of concrete

Footings-0.8% of total volume of concrete

Example:

How to calculate the steel quantity of slab having the Length, width, and depth of the slab is 9 m x 4 m x 0.125 m

 how to calculate the Volume of Concrete

The Total Volume of Concrete for given Slab = 5 x 4 x 0.15

= 4.5 m3

Calculate the steel quantity  formula

Thumb rule to estimate Steel quantity of above slabs he gives approximate value

= Volume of Concrete x Density of Steel x percentage of Steel of Member

Steel weight required for above slab = 4.5 x 7850 x 0.01 = 353.25 Kg

Thumb Rules for Shuttering area:

Shuttering costs is taken as 14-17% of the total construction of the building. Shuttering work is done to bring the concrete in Shape and size. Thumb rule to estimate  shuttering required is 6 time the quantity of concrete or 2.4 times of Plinth area. (thumb rule)

For example, the concrete quantity is 0.6m3, then

Area of Shuttering is 0.6 x 6 = 3.6m2

part of Shuttering:-

The Shuttering plate Plywood, Battens, Nails are components of Shuttering.

quantity eastimate shuttering plywood

Suppose, The shuttering Plywood has a length, width & depth of 2.44 x 1.22 x 0.012

The No. of Shuttering Plywood sheets = 0.22 times of Shuttering

let, the shuttering area = 3m

Then Plywood required for shuttering = 0.22 x 3 = 0.66m2

Quantity Calculation in batten

Shuttering batten usually has a length & width of 75mm x 40mm.

Batten Quantity = 19.82 x No. of Plywood Sheets

If work requires 25 Ply sheets, the total quantity of Battens are 19.82 x 25 = 495 Battens

Nails & Binding Wire Quantity in Shuttering:

Approximately, 75 gms of Nails used in the shuttering of the 1m2 area.

75gms of Binding wire is used for every 1m2 of Shuttering.

Thumb rule for Shuttering oil estimation :

Shuttering oil is applied on the shuttering plate surface used to de-frame or de-assemble from the concrete easily.

Total required Shuttering oil  = 0.065 x Total Area of Shuttering

(or)

For every 15m2 of shuttering 1 liter of shuttering oil is consumed.

Example :

If, total area of shuttering is 14 m2, then Shuttering oil Consumption = 0.065 x 14 = 0.91.

 

Thumb rule for estimation in civil engineering 

 thumb rule for  Cement, Sand, Coarse Aggregate Quantity in Different grades of Concrete :

Concrete Mix Cement Quantity,Coarse Aggregate Quantity,Fine Aggregate Quantity

M5 (1:5:10)    2.82 Bags                  0.98m3                                           0.49m3

M7.5(1:4:8)    3.48 Bags                  0.97m3                                         0.48m3

M10(1:3:6)     4.50 Bags                  0.90m3                                         0.45m3

M15(1:2:4)     6.60 Bags                  0.88m3                                         0.44m3

M20(1:1.5:3)     8.40 Bags                  0.84m3                                         0.42m3

Note: 1 bag of cement = 50Kgs  

Thumb rule for quantity surveys 

Thumb rule for Cement quantity in Cement Masonry & Plastering and brickwork 

work in construction

Thumb rule for bricks work

Brickwork for 1m3	Cement Qty in m3	Cement Qty in Bags
230 mm Brickwork	0.876bags/m3	43.80kgs
115 mm Brickwork	0.218bags/m3	10.90kgs

Cement Masonry Quantity Thumb Rule:

Cement Masonry Type & Mix	Cement Qty in Bags	Cement Qty in Kgs
200mm Cement Masonry work ratio 1:6	0.124Bags/m2	6.2Kgs/m2
150mm Cement Masonry work ratio 1:6	0.093Bags/m2	4.65Kgs/m2
200mm Cement Masonry work ratio 1:4	0.206Bags/m2	10.3Kgs/m2
150mm Cement Masonry work ratio 1:4	0.144Bags/m2	7.2Kgs/m2
100mm Cement Masonry work ratio 1:4	0.103Bags/m2	5.15Kgs/m2

Plastering Quantity Thumb Rule:

Type of Plastering	Cement Qty in Bags	Cement Qty in Kgs
Rough Plastering	0.09Bags/m2	4.5Kgs/m2
Internal Wall Plastering	0.09Bags/m2	4.5Kgs/m2
Duct Plastering	0.09Bags/m2	4.5Kgs/m2
External Wall plastering	0.175Bags/m2	8.75Kgs/m2
Stucco Plastering	0.175Bags/m2	8.75Kgs/m2
Lathen Plastering	0.55Bags/m2	27.5Kgs/m2