Thumb Rules for Civil Engineering Construction are quick formula used by Civil Engineers and Quantity Surveyors to estimate the quantities of materials, strength, and reinforcement needed for a construction project. These thumb rules are widely used in Civil Site Engineering and are helpful to calculate Steel in RCC, Brick Calculation, Concrete Mix Design and Shuttering Work. They can be found in Civil Engineering pdfs and are based on past experiences and common practices, but it’s important to adapt them for specific requirements of each construction project.
Thumb Rules For Civil Site Engineer pdf
Thumb Rules For Civil Engineeringis essential for anycivil engineer, Site engineer, or civil supervisor. They play a crucial role while taking quick decisions on site. There is some Civil Engineering Basic Knowledgethat every civil engineer must know.
Thumb Rule of Civil Engineeringor the thumb rule for construction helps you in finding out the solution using a simplemathematical formulaand make smart decisions whenever needed.
But, while using thesethumb rules, you must remember that the thumb rule never gives the exact or accurate results, you just have used them forapproximate results.
There isa numberofThumb Rule For Civil Engineersthat we used inconstruction work. So, the following are some most frequently used Thumb rules on theConstruction site.
The Thumb rule method is anapproximate&comparing method.In thumb rules and theunitsare not the same when we compare to get the results. So, ignoreunitswhile performing thethumb rule.
Thumb Rules for Civil Engineering In Construction
Following are thumb rules in Civil Engineering,
1.Thumb Rule for Concrete Volume
Thevolume of concreterequired =0.038 m3/square feetarea
Example:-If Plan Area = 40 x 20 =800 Sq. m.
So, for the plan area of800 Sq. m.the area the total volume ofconcreterequired
= 800 x 0.038m3 =30.4m3
2.Thumb Rule for Steel Quantity for Slab, Beams, Footings & Columns
Following are some importantthumb rulesforsteel calculationfor slab, beam, column, and footings.
Steel required inresidentialbuildings= 4.5 Kgs – 4.75 Kgs / sq. Ft.
Steel required ForCommercialbuildings= 5.0 Kgs-5.50 Kgs/Sq. Ft.
You can also useBN Dattarecommendations for the more accurate result,
The following recommendationsThumb Rules For Civil Engineering are given in B N Datta for the Steel quantity used in different members of the building.
3.Percentage of Steel in Structural Members
Following are thumb rules forreinforcement in concretemembers,
- Slab–1%of the total volume of concrete (Slab steel calculationthumb rule)
- Beam–2%of the total volume of concrete
- Column–2.5% of total volume of concrete
- Footings–0.8%of the total volume of concrete
Example:
How to calculate thesteel quantityof slab having the Length, width, and depth of the slab is5m x 4m x 0.15m
Step 1: Calculate the Volume of Concrete:
The Total Volume ofConcretefor given Slab =5 x 4 x 0.15
=3m3
Step 2: Calculate The Steel Quantity Using Formula:
As per the guidelines are given in theBN Duttareference book thesteel quantityof slab is1%of thetotal volumeof concrete utilized.
Thumb rule to estimate Steel quantity of above slab =Volume of Concrete x Density of Steel x % of Steel of Member
Steel weight required for above slab = 3 x 7850 x 0.01 =235 Kgs
For accurateestimation, you can refer toBar Bending Schedule
4. Thumb Rules For Shuttering Work
Shutteringcosts are taken as15-18%of thetotal constructionof the building.Shuttering workis done to bring the concrete in Shape. The Thumb rule to estimate theshutteringrequired is6 timesthe quantity of concrete or 2.4 times of thePlinth area.
For example, theconcrete quantity is 0.5m3, then
Area ofShutteringis 0.5 x 6 = 3m2
Components of Shuttering
The Shuttering platePly, Battens, Nailsare components of Shuttering.
Shuttering Ply Quantity estimation
Suppose, TheShuttering Plyhas a length, width & depth of 2.44 x 1.22 x 0.012
The No. of ShutteringPly Sheets = 0.22times of Shuttering
Suppose, theShuttering Area= 3m
Then Ply required for shuttering = 0.22 x 3 =0.66m2
5.Battens Quantity Calculation
Shuttering Battenusually has alength&widthof 75mm x 40mm.
Batten Quantity =19.82 x No. of Ply Sheets
If work requires25 Ply sheets,the total quantity of Battens are 19.82 x 25 =495Battens
Nails & Binding Wire Quantity in Shuttering:
Approximately,
75 gramsofNailswere used in the shuttering of the1m2area.
75gms ofBinding wireis used for every 1m2of Shuttering.
Thumb rule for Shuttering oil estimation :
Shuttering oil is applied on theshuttering platesurface used tode-frameorde-assemblefrom the concrete easily.
Total required Shuttering oil = 0.065 x Total Area of Shuttering
(or)
For every15m2of shuttering1 literofshuttering oilis consumed.
Example :
If, total area of shuttering is 15 m2, then Shutteringoil Consumption=0.065 x 15 =0.975.
6. Thumb Rule for Cement, Sand, Coarse Aggregate Quantity Calculations
Note: 1 bag of cement = 50Kgs
Thumb rule for Cement required inBrickwork,Cement Masonry&Plasteringwork in construction.
7. Thumb Rule for Concrete Mix Designs
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%, the yield will be decreased by 0.03 cu.m per 1 cu.m.
3. Decreased by 1%, then the slump value will be decreased by about 12.5 mm.
4. Decreased by 1%, then the durability of the concrete will be reduced by 10%.
8. Basic Thumb Rules Used in Building Construction
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. Use high strength concrete in columns
The high strength may reduce the column size or the amount of reinforcing steel required for the column.
7. Use high early strength concrete
This will allow for earlier form stripping and will reduce total construction time.
8. 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.
9. 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.
10. Use the 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.
11. 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.
12. Eliminate bent bars where possible
Bent bars increase fabrication costs and require greater storage area and sorting time on the job site.
13. Avoid the congestion of steel
Congestion of bars should be avoided, especially at beam-column joints, so that all reinforcements can be properly placed.
9. Thumb Rules For Civil Engineers for Brickwork or Brick Calculation
following areThumb Rules for civil engineeringfor brickwork andcement quantitycalculations.
| Brickwork for 1m3 | Cement Qty in m3 | Cement Qty in Bags |
| 230 mm Brickwork | 0.876m3 | 25.4 Bags |
| 115 mm Brickwork | 0.218m3 | 6.32 Bags |
Thumb Rules for Civil Engineering
10. Thumb Rules For Cement Masonry Quantity
| Cement Masonry Type & Mix | Cement Qty in Bags | Cement Qty in Kgs |
| 200mm in Cement Masonry work of Ratio 1:6 | 0.124Bags/m2 | 6.2Kgs/m2 |
| 150mm in Cement Masonry work of Ratio 1:6 | 0.093Bags/m2 | 4.65Kgs/m2 |
| 200mm in Cement Masonry work of Ratio 1:4 | 0.206Bags/m2 | 10.3Kgs/m2 |
| 150mm in Cement Masonry work of Ratio 1:4 | 0.144Bags/m2 | 7.2Kgs/m2 |
| 100mm in Cement Masonry work of Ratio 1:4 | 0.103Bags/m2 | 5.15Kgs/m2 |
Thumb Rules for Civil Engineering
11. Thumb Rules Plastering Quantity
| Type of Plastering | Cement Qty in Bags | Cement Qty in Kgs |
| Rough Plastering | 0.09 Bags/m2 | 4. 5Kgs/m2 |
| Internal Wall Plastering | 0.09 Bags/m2 | 4.5 Kgs/m2 |
| Duct Plastering | 0.09 Bags/m2 | 4.5 Kgs/m2 |
| External Wall plastering | 0.175 Bags/m2 | 8.75 Kgs/m2 |
| Stucco Plastering | 0.175 Bags/m2 | 8.75 Kgs/m2 |
| Lathen Plastering | 0.55 Bags/m2 | 27.5 Kgs/m2 |
Thumb Rules for civil engineering
12. Types of Area and Some Useful Requirements for Building:
1. Carpet area:
The actual area you use. The area on which ‘you can put a carpet’.
2. Built up area:
Carpet area + area of walls and ducts. Around 10% more than the carpet area. A terrace is considered as half the actual area for calculating built up area. Some projects charge dry terrace same as internal rooms.
3. Super built up / Saleable area:
Built up area + markup for common spaces like lifts and stairs. Usually 25% more than the built up area.
FAQs
What is Thumb Rule?
Therule of thumb is colloquially referred to as a thumb rule. A Thumb Rule is a guideline which provides concise advice on a given subject. It is a general concept that offers specificguidancefor executing or approaching a given task. Thumb rules usually evolve as a result of practice and experience rather than a theoretical study.
How do you calculate the steel by thumb rule?
Following are Thumb Rule for reinforcement steel in concrete members,
- Slab – 1% of the total volume of concrete (Slab steel calculation thumb rule)
- Beam – 2% of the total volume of concrete Thumb Rule for Shuttering Work
- Column – 2.5% of the total volume of concrete
- Footings – 0.8% of the total volume of concrete
What is a Good Rule of Thumb?
Thumb Rulecan be called a guideline, idea, or principle that helps you make quick decisions.“Arrive early”is an efficient good Thumb Rule for most appointments. It referred to builders who frequently use their thumb to estimate measurements. It is a helpful rule even being inexact. Thumb Rule for Shuttering Work
What is the Basic Knowledge of Civil Engineering?
BASIC THINGS CIVIL ENGINEERSSHOULD KNOW,
- Lapping in reinforcement is not allowed for the bars having diameters more than 36 mm.
- Steel Char maximum spacing is 1.00 m (or) 1 No per 1m2.
- In steel dowels, a rod minimum of 12 mm diameter should be used.
- Steel Chairs minimum of 12 mm diameter bars to be used.
- Longitudinal reinforcement should not be less than 0.8% and more than 6% of gross C/S.
- The minimum bars used for a square column are 4 No’s and 6 No’s for the circular column. Thumb Rules for Steel in RCC
What is the Thumb Rule to determine Beam Depth?
The method for determining the width-depth ratio of reinforced concrete beams is not specifically given in codes. However, a thumb rule can be used i.e taking depth that is two and a half to three times the beam’s width. For long-span beams, it is generally economical to use deep and narrow sections. Thumb Rule for Concrete Mix Design
Thumb Rules For Civil Site Engineer pdf
Thumb Rules For Civil Engineeringpdf is essential for any civil engineer, Site engineer, or civil supervisor. They play a crucial role while taking quick decisions on site. There is somecivil engineering basic knowledgethat every civil engineer must know.
Thumb Rules for Civil Engineering
Thumb rulerequirement of standard materials and standard calculation in high raised building,
- Steel =3 to 5 kg / sqft.
- Cement =0.5bags/ sqft.
- RMC =0.05 m3/sqft.
- Block =12.5 nos /sqm.
- Electrical cast = Rs 133/sqft. Thumb Rule for Brick Calculation
- Plumbing cost = Rs 126/sqft.
- Fire fighting cost = Rs 40/sqft.
- External development = Rs 94.5/sqft. Thumb Rule for Concrete Mix Design
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Conclusion:
In conclusion, thumb rules in civil engineering construction are a quick and easy methods o formula used to estimate quantities, strength, reinforcement etc. They can be useful for quickly estimating the amount of materials needed for a project, but it’s important to double-check the calculations with detailed measurements and consult with relevant professionals. These thumb rules are based on past experiences and common practices and it’s necessary to adapt them to the specific requirements of each construction project.
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