# Tips you must know while working in construction site

There are so many standard, you can write a Code about it 😀 but I’m writing as keeping in mind about ‘construction site’

(Based on IS 456 and many other but mostly ** INDIAN standards. **Took me a LOTS of hour to collect everything and type it, hope it helps :D)

**TOLERANCE**:

**Form work:-**

- In C/S for columns & Beams deviation is = + 12mm more (or) – 6mm less in size
- In footing plan = + 50 mm more (or) – 12 mm less size
- In depth = ± 0.05 D (specified thickness).

**Reinforcement**:-

- For effective depth D < 200mm = ±10mm
- For effective depth D > 200mm = ±15mm
- For Cover to reinforcement = +10mm
- Maximum freefall of concrete = 1.50 m height.

**TOLERANCE FOR CUTTING LENGTH :**

- When the specified length is not given = + 75mm (or) – 25 mm
- When the min. length is specified = + 50 mm (or) – 0 mm

**Accuracy of measuring equipment in batching plant.**

- Cement : + 2%
- Aggregate : + 3%
- Admixture : + 3%
- Water : + 3%
- Mixing time : 2 minutes for one mixing.(site Mixing)

**Slump IS 456**

- Lightly reinforced 25 – 75 mm
- Heavily reinforced 75 – 100 mm
- Trench fill (insitu & Tremie) 100 – 150 mm (For Termie vibrator not required)

**SIMPLEX FORMULA:-**

**U = (N /L) x {(W x H) / (1 + S)} x Sq.rt {(L/50)}**

Where,

U = Ultimate load in tones N = Number of blows L = Pile length in feets W = Weight of hammer in tones H = Height of fall in feet. S = Set for 1 blows in Inch

Safe load = (ultimate load/ 2.5)

Factor of safety = 2.5

10 blows = below 10 MM

**Durability:**

1. Environment

2. Cover to Steel

3. Type and quality of the constituent material

4. Cement content and Water Cement ratio.

5. Workmanship to obtain full compaction.

6. Compaction and efficient curing.

**GENERAL**:

- Lapping is not allowed for the bars having diameters more than 36 mm.
- Chair spacing maximum spacing is 1.00 m (or) 1 No per 1 Sq.m
- For dowels rod minimum of 12 mm dia should be used.
- Chairs minimum of 12 mm dia bars to be used.
- Longitudinal reinforcement not less than 0.8% and more than 6% of gross C/S.
- Minimum bars for square column is 4 No’s and 6 No’s for circular column.
- Main bars in the slabs shall not be less than 8 mm (HYSD) or 10 mm (Plain bars) and the distributors not less than 8 mm and not more than 1/8 of slab thickness.
- Minimum thickness of slab is 125 mm
- Dimension tolerance for cubes + 2 mm.
- Free fall of concrete is allowed maximum to 1.50m.
- Lap slices not be used for bar larger than 36 mm.
- Water absorption not more than 15 %.
- PH value of the water should not be less than 6.
- Compressive strength of Bricks is 3.5 N / mm2
- In steel reinforcement binding wire required is 8 kg per MT
- In soil filling as per IS code 100 sqm should take 3 sample for core cutting test

**DENSITY OF MATERIALS:**

- Weight of Bricks = 1600-1920 Kg/M3
- Weight of Block work = 1920 Kg/M3
- Weight of R.C.C = 2310 – 2700 Kg/M3

**CURING**

- Super Sulphate cement : 7days
- Ordinary Portland cement 10 days
- Minerals & Admixture added cement : 14 days

**STRIPPING TIME ( De-Shuttering ):-**

- For columns, walls, vertical form works : 16-24 hrs
- Soffit formwork to slabs : 3 days (props to be refixed after removal)
- Soffit to beams props : 7 days props to refix after removal.
- Spanning up to 4.50m :7 days
- Spanning over 4.50m :14 days
- Arches spanning up to 6m :14 days
- Arches spanning over 6m : 21 days

**CUBE SAMPLES:**

- 1 – 5 M³ : 1No.
- 6 – 15 M³ : 2 No
- 16 – 30 M³ : 3No
- 31 – 50 M³ : 4No
- Above 50 M³ : 4+1 No of additional sample for each 50M³

**TEST RESULTS OF SAMPLES:**

- The test results of the samples shall be the average of the strength of three specimens.
- The individual variation should not be more than + 15 % of the average.
- If more the results of the sample are invalid.

**COMPRESSIVE STRENGTH**:

- 3 days – 45 %
- 7 days – 67 to 70%
- 14 days – 85%
- 28 days – 100%
- M20 = 0.55
- M25 = 0.50
- M30 = 0.45
- M35 = 0.45
- M40 = 0.40

**SPACING OF BARS*:**

- Provide the dia of the bar, if the dia of the bar are equal.
- Provide the dia of the larger bar, if the dia are unequal.
- 5mm more than the nominal maximum size of the coarse aggregate.

*Note- calculate the spacing for good approach…they are just for site.*

**COVER TO MAIN REINFORCEMENT:-**

- Column : 40 mm (D>12mm)
- Column : 25 mm (D= 12mm)
- Beam : 25 mm Slab : 15 mm (or) not less than dia of the bar.
- Footing : 50 mm
- Sunshade (Chajja) : 25mm

**QUANTITIES REQUIRED**:

- Plastering (CM 1:3) = 1.50 bags / 10 m²
- Plastering (CM 1:5) = 1.05 bags / 10 m²
- Ceiling Plastering (CM 1:3) = 48 kg / 10 m²
- Brick work (CM 1:5) = 86 Kg / 10 m³
- Brick work (CM 1:6) 9″thick = 80.64 Kg / 10 m³
- Brick work (CM 1:3) 4½” thick = 15.46 Kg / 10 m³
- Lime for white washing = 10 Kg/100 m²
- Painting = 10 ltr/ 100 m²
- Distemper 1st coat = 6.5 Kg / 100 m²
- Distemper 2nd coat = 5 Kg / 100 m²
- Snowcem 1st coat = 30 Kg / 100 m²
- Snowcem 2nd coat = 20 Kg / 100 m²
- Paint ready mixed one coat = 10 ltr / 100 m²
- Weathering Course = 7.68 Kg / m²
- Flooring = 8.10 kg / m²
- Pressed tiles for weathering course (CM 1:3) = 7.68 Kg / 10 m²
- Granolithic floor finish = 8.10 Kg / 10 m²

**STEEL**:-

- Weight of rod per meter length = d2 / 162 where d in mm
- “L” for column main rod in footing is minimum of 300mm
- Hook for stirrups is 9D for one side
- For Cantilever anchorage length for main steel is 69D
- No. of stirrups = (clear span/Spanning) + 1
- Design strength is M 40, target strength is 1.25 x 40 = 50 Mpa

**Other General Notes for civil Engineering**

- Electrical conduits shall not run in column
- Earth work excavation for basement above 3 m Should be stepped form
- Any Back filling shall be compacted 95% of dry density at the optimum moisture content and in layers not more than 200mm for filling above structure and 300 mm for no structure
- F SOLING IS SPECIFIED THE SOLING STONES SHALL BE LAID AT45° TO 60° INCLINATION (AND NOT VERTICAL) WITH INTERSTICES FILLED WITH SAND OR MOORUM.
- Y REPRESENTS TOR STEEL GRADE – Fe-415 OF IS:1786. WITH CHARECTERISTIC YIELD STRENGTH OF 415 N/MM MINIMUM.
- ∅ REPRESENTS MILD STEEL GRADE – 1 OF IS:432 (PART-1)
- ALL REINFORCEMENT SHALL BE FREE FROM MILL SCALES, LOOSE RUST & COATS OF PAINTS, OIL OR ANY OTHER SUBSTANCES.
- BY PROVIDING PROPER COVER BLOCKS, SPACERS, CHAIRS ETC.. ALL REINFORCEMENT SHALL BE PLACED AND MAINTAINED IN POSITION AS SHOWN IN STRUCTURAL DRAWING
- CEMENT SHALL BE 43 GRADE ORDINARY PORTLAND CEMENT CONFORMING TO IS:8112 OR53 GRADE ORDINARY PORTLAND CEMENT CONFORMING TO IS:12269-1987.
- CEMENT SHALL BE STORED IN DRY PLACES ON A RAISED PLATFORM ABOUT 200mm ABOVE FLOOR LEVEL AND 300mm AWAY FROM WALLS. BAGS TO BE STACKED NOT MORE THAN 10 BAGS HIGH IN SUCH A MANNER THAT IT IS ADEQUATELY PROTECTED FROM MOISTURE AND CONTAMINATION.
- WATER USED FOR BOTH MIXING AND CURING SHALL BE CLEAN AND FREE FROM INJURIOUS AMOUNTS OF OILS, ACIDS, ALKALIS, SALTS, SUGAR AND ORGANIC MATERIALS OR OTHER SUBSTANCES THAT MAY BE DELETERIOUS TO CONCRETE OR STEEL. THE pH SHALL BE GENERALLYBETWEEN 6 AND 8.
- CEMENT SHALL BE TESTED FOR ITS SETTING.
- 1. THE INITIAL SETTING TIME SHALL NOT BE LESS THAN 30 MINUTES.
- 2. THE FINAL SETTING TIME SHALL NOT BE MORE THAN 10 HOURS.

- SAMPLES FROM FRESH CONCRETE SHALL BE TAKEN AND AT LEAST A SET OF 6 CUBES OF 150mm SHALL BE PREPARED AND CURED. 3 CUBES EACH AT 7 DAYS AND 28 DAYS SHALL BE TESTED FOR COMPRESSIVE STRENGTH. THE TEST RESULTS SHOULD BE SUBMITTED TO ENGINEER FORAPPROVAL. IF RESULTS ARE UNSATISFACTORY NECESSARY ACTION/RECTIFICATION/REMEDIAL MEASURES HAS TO BE EXERCISED.
- A SET OF CUBE TESTS SHALL BE CARRIED OUT FOR EACH 30 Cum OF CONCRETE / EACH LEVELS OF CASTING / EACH BATCH OF CEMENT.
- WATER CEMENT RATIO FOR DIFFERENT GRADES OF CONCRETE SHALL NOT EXCEED 0.45 FOR M20 AND ABOVE AND 0.50 FOR M10 / M15 CONTRACTOR / MIX DESIGNER TO CARRY OUT THE NECESSARY INITIAL (PRELIMINARY) TESTS. FOR CONCRETE GRADES M20 AND ABOVE APPROVED ADMIXTURE SHALL BE USED AS PER MIX DESIGN REQUIREMENTS.

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