Thumb rule for steel..Based on
concrete volume
1.
For beam = 2% of concrete volume
2.
For slab = 1% of concrete volume
3.
For column= 2.5 % of concrete
volume..
How to use
Example..
For 1 cubic meter volume of column
required steel…
Column steel= (% steel thumb rule)*(steel
density)*(volume of concrete)
= 0.025 * 7850*1
= 196.25. Kg
Approx..200kg for 1 m3 volume of column..
Thumb rules based on day by day practice &
experience in construction field…
my senior engineer tell me in case of immediate/
urgency we use this rule..many times it helpful…
General thumb rules…. for ‘1m3’
concrete volume
1.
For M20(1:1.5:3)
8.4 bag cement, 0.84 m3 CA, 0.42m3 sand.
2. For M15 (1:2:4)
6.6bag cement, 0.88 m3 CA, 0.44m3 sand.
3. For M10 (1:3:6)
4.5 bag cement, 0.90m3 CA, 0.45m3 sand.
FOR HIGH RAISE BUILDING :-
Thumb rule requirement of standard
materials and standard calculation in high raised building
·
Steel =3 to 5 kg / sft
·
Cement =.5bags/ sft
·
RMC =.05 m3/sft
·
Block =12.5 nos /sqm
·
Electrical cast = Rs 133/sft
·
Plumbing cost = Rs 126/sft
·
Fire fighting cost = Rs 40/sft
·
External development = Rs 94.5/sft
·
Civil works-Structure = RS 751.25/sft
·
Finishing works = RS 467.50/sft
·
200 mm in cm 1:6 =0.124Bags /sqm
·
200 mm in cm 1:4 =0.206 bags/sqm
·
150 mm in cm 1:6 =0.093 bags/sqm
·
150mm in cm 1:4 =0.144 bags/sqm
·
100 mm in cm 1:4 =0.103 bags/sqm
·
Ceiling plastering =0.11 bags/sqm
·
Wall plastering =0.09 bags/sqm
·
Rough plastering =0.09 bags/sqm
·
Duct plastering =0.09 bags/sqm
·
External plastering =0.175 bags/sqm
·
lathen plastering =0.55 bags/sqm
·
stucco plaster =0.175 bags/sqm
·
100 mm plaster band =0.012 bags/rmt
·
pcc 1: 4: 8 =3.4 bags/cum
·
pcc 1:5:10 =2.52 bags/cum
·
pcc 1:3:6 =4.2 bags/cum
·
pcc 1:2:4 =6.02 bags/cum
·
230 mm brick =0.876 bags/cum
·
115 mm brick work =0.218 bags/cum
·
vdf 100 mm thick =0.82 bags/sqm
·
granolithic flooring =40 mm 0.35
bags/sqm
·
granolithic flooring =20 mm 0.28
bags/sqm
·
anti-skid =0.28 bags/sqm
·
ceramic =0.28 bags/sqm
·
vertified tile flooring =0.28
bags/sqm
·
vertified tile dado =0.27 bags/sqm
·
cerami dado =0.27 bags/sqm
·
marble flooring =0.3 bags/sqm
·
100 mm ht marble skerting =0.027
bags/rmt
·
marble glading =0.27 bags/sqm
·
terracota tle flooring =0.3 bags/sqm
·
mangalore tile =0.3 bags/sqm
·
Door frame fixing =0.17 bags/sqm
·
water proofing for sunken slab =0.23
bags/sqm
·
water proofing for walls =0.23 bags/sqm
·
water proofing for balcony/toilets
=0.65 bags/sqm
· Anti terminate treatment chemical
Name is chloropyrifoc 20% . Diluting5 Lit of Chemical with 95 Lit of water and
usage is 7.5 Sqm Per liter {Diluted} .To Provide 1” Dia hole And Deep1Foot
Labour Productivity thump rule :-
Brick work
1 mason 1 Men mazdoor 1.25 sqm
1 Women Mazdoor
Wall Plastering 1 mason
1 Men mazdoor 10 sqm
1 Women Mazdoor
Ceiling Plastering 1 mason
1 Men mazdoor 8 sqm
1 Women Mazdoor
External Plastering 1 mason
1 Men mazdoor 8 sqm
1 Women Mazdoor
Block work 8” 1 mason
1 Men mazdoor 10 sqm
1 Women Mazdoor
Block work 6” 1 mason
1 Men mazdoor 8 sqm
1 Women Mazdoor
Block work 4” 1 mason
1 Men mazdoor 8 sqm
1 Women Mazdoor
Carpenter 1 Skilled
1 Un skilled 4 Sqm
Bar bender 1 Skilled
1 UN skilled 200Kg
Tile work 1 Mason
1M Mazdoor 10 Sqm
Paint
Painter skilled OBD 600 Sft
Emulsion 800 Sft
Putty 600 Sft
Primer 800 Sft
Miscellineous thumb rule in
construction :-
·
External Painting
Ace-Low quality
Apex-Medium Quality
Apex ultima –High Quality
·
One Sqm =10.763Sft
·
One Cum =35.314 Cft
·
One Acres=4046.873 Sqm=43560.17
Sft=4840.019Yards
·
One Cubic meter = 1000 litere
·
One Meter =3.280Feet
·
One Mile =1609.344 meter
·
One Acre = 100 cent
·
One ground =2400 Sft=5.51 cent
·
½ ground =2.75 cent
·
One Mile =8 Furlong
·
One cement bag =1.25 Cft
·
One Forma box =1*1*1.25 feet
THUMB RULES FOR CONCRETE MIX DESIGN
FOR ADDING 4 LITERS OF WATER IN 1 CU.M FRESHLY
MIXED CONCRETE
1. The slump value will be increased by 25 mm.
2. The compressive strength of concrete will be
decreased by 1.5 to 2.0 N/mm2
3. The shrinkage potential will be increased by
10%.
4. 1/4 bag of cement will be wasted.
IF THE TEMPERATURE OF FRESHLY MIXED CONCRETE IS
INCREASED BY 1%, THEN
1. 4 liters of water per cu.m will give equal
slump.
2. The air content will be decreased by 1%.
3. The compressive strength of concrete will be
decreased by 1.0 to 1.5 N/mm2.
IF THE AIR CONTENT OF FRESHLY MIXED CONCRETE IS
1. Increased by 1% then the compressive strength will
be decreased by 5 %.
2. Decreased by 1%, yield will be decreased by 0.03
cu.m per 1 cu.m.
3. Decreased by 1%, then the slump value will be
decreased about 12.5 mm.
4. Decreased by 1%, then the durability of the
concrete will be reduced by 10%.
The following are some of the rules
of thumb which will be useful to achieve economy:
Minimize floor-to-floor height:
By minimizing the floor-to-floor height, the cost
associated with mechanical services, stairs, exterior building cladding can be
significantly reduced.
Use repetitive formwork
The cost of formwork may be very high and is not
given due consideration by the designers. The cost can be reduced when the
framing system is used repetitively (10 or more times) on a structure.
Use standard column size
This can be achieved by varying the amount of
reinforcing steel and the concrete strength within the column. This will allow
for a single column form and will minimize the number of variations to meet
beam or slab forms.
Adopt uniform column layout
Uniform column layout results in simple formwork,
which can be used repetitively from floor-to-floor. Similarly, regular shaped
buildings will be more economical than irregularly shaped buildings with L- or
T-shaped columns.
As far as possible, use the same depth for beams
The saving in formwork and shoring costs will
exceed any additional costs for concrete and reinforcing steel. This will also
provide a uniform ceiling elevation and minimize mechanical service
installation difficulties.
Use high strength concrete in columns
The high strength may reduce the column size or the
amount of reinforcing steel required for the column.
Use high early strength concrete
This will allow for earlier form stripping and will
reduce total construction time.
Specify self-consolidating concrete
Heavily reinforced columns and beams can be very
congested with rebar, which prevents the proper placement of the concrete. SSC
maximizes concrete flowability without harmful segregation and dramatically
minimize honeycombing and air pockets.
Specify locally available materials
The use of local aggregates and recycled materials
in concrete makes it a 'green' product, which is requested by environmentally
responsible owners.
Use commonly available size of bars and spirals
For a single structural member, the number of
different sizes of bars should be kept to a minimum.
Use the largest bar size that satisfies the design
considerations
Use larger size bars in columns and smaller size
bars in slabs. Larger diameter bars reduce the number of bars that must be
placed and minimize installation costs.
Eliminate bent bars where possible
Bent bars increase fabrication costs and require
greater storage area and sorting time on the job site.
Avoid congestion of steel
Congestion of bars should be avoided, especially at
beam-column joints, so that all reinforcements can be properly placed.
