Civil Engineer must have knowledge | civil Engineer tips

• ASTM Abbrevation : American Society for Testing Materials
• Grade of Concrete is denoted as Cement: Sand: Aggregate (Ex M20 Grade : 1:1.5:3)
• C/C means Center to Center Distance
• DL means Development Length
• Lapping of bars not allowed if the dia of bar is more than 36mm.
• For circular column minimum of 6 longitudinal bars are used.
• The minimum thickness of slab is 0.125m
• Water pH value less than 6 should not be used for construction purpose.
• The concrete Should not be thrown from a height more than 1m.
• The Compressive strength of Bricks is 3.5 N /mm²
• The initial setting time shall not be less than 30 minutes and the final setting time of cement is 10hours.
• Dead Load means Self weight of Structure
• Sand having moisture content more than 5% should not be used for Concrete mix.
• DPC means Damp Proof Course. The thickness of DPC should not be less than 2.5cm.
• Cube test is carried out for each 30m³ usage of concrete.
• RMC : Ready Mix concrete, The concrete is made at factory and transported to the site, This type of concrete is used where there is a lack of space for mixing the concrete and used where a huge amount of concrete is required for construction.
• The height of floor is usually 3m or 10ft (If a person asks you whats the height of 12 storied building? Ans: 3m x 12floors = 36m)
• A head mason can work 25-30m³ in a day.
• In construction, the rate analysis for the work of workers is calculated in Man Hours. (Ex: 10$ for 1 Man hour)

• Cantilever Beam has One fixed support and the other end is free, Simply supported beam has a minimum of two supports.
• PCC (Plain Cement Concrete) this type of concrete is used on members only when the tensile forces are not  acting on it.
• The weight of first class clay brick should be 3.85 Kg. and it has a crushing strength of 10.5MN/m²
• Adding more water in the concrete mix to increase setting time leads to form the Cracks or honeycomb in hardened concrete.
• Vibration in freshly made concrete is done to remove the air bubbles in concrete mix.
• Impermeability of concrete:  The concrete which resists the the entry of water or moisture into it.
• The concrete can be lifted to a maximum height of 50m using Concrete Pumps.
• The curing Period of RCC is 28days.
• The minimum sill level height should be 44 inches.
• The transverse reinforcement provided in columns are called Ties.
• The transverse reinforcement provided in Beams is called as Stirrups.
• Stirrups in Beams and Ties in Column are provided to handle the shear force and to keep longitudinal bars in position.

• The Prime reason for using steel as reinforcement is due to thermal expansion. The thermal expansion coefficient of concrete and steel is (approximately) same having value 12×10−6/°C

• M20 grade of concrete is generally used in the construction of slab.
• Weight of Bar is calculated using formula D²/162 (D = Dia of bar in mm)
• The No. of Bricks required for 1m³ of Brick masonary are 550 bricks.
• Specific gravity of Cement is 3.16g/cm³; Bricks is 2g/cm³;  Sand is 2.65g/cm³ ,
• Standard Size of Brick is 19cm x 9cm x 4 cm or 19cm or 9cm x 9 cm
• Floor area occupied by 50kg of Cement bag is 0.3m² and height of 0.18m.
• As per IS 456: 2000, Maximum dia of bar used in the slab should not exceed 1/8th of the total thickness of the slab.
• IS 456:2000 is Code of Practice for Plain and Reinforced Concrete
• IS 800:2000 is code of Practice for General steel construction
• The slope or Pitch of the stair should be in between 25 degrees to 40 degrees.
• The rise in stairs is in between 150mm to 200mm.
• Tread in staircase is in between 250mm to 300mm.
• Hook length should not be less than 9D (Dia of Bar)
• Unit weight of PCC is 24KN/m³ , RCC is 25 KN/m³ , Steel is 7850Kg/m³
• The volume of 50kg cement bag is 1.3CFT.
• Theodolite least count is 20Secs whereas Compass Least count is 30mins.
• TMT bars : TMT means Thermo Mechanically treated bars
• Cement more than 3 months old cannot be used for construction
• The length of each bar from factory is 12m. 

Must Remember the Concrete Mix ratio of Different grades of Concrete atleast till M20 grade of concrete

Concrete Grade	Mix Ratio
M5	1:5:10
M7.5	1:4:8
M10	1:3:6
M15	1:2:4
M20	1:1.5:3
M25	1:1:2
M30, M35, M40, M45, M50, M55, M60, M65, M70	Design Mix

Know about the Slump value of Concrete for Different concrete works

Concrete Mixes	Slump range in mm
Columns, Retaining walls	75-150mm
Beams & Slabs	50-100mm
CC Pavements	20-30mm
Decks of bridge	30-75mm
Vibrated Concrete	12-25mm
Huge Mass constructions	25-50mm