What are the basic things to civil engineer should know? (PART

What are the basic things to civil engineer should know? (PART _I)

As a civil engineer you must know about some basics things that is always useful everywhere.

UNIT CONVERSIONS

Lenth wise

1 cm = 10 mm | 1 inch = 2.54 cm

1 m = 1000 mm or 100 cm | 1 foot = 12 inch

1 km = 1000 m | 1 yard = 3 ft

1 foot/feet = 0.3048 m |

1 m = 3.28 ft. |

1 mile = 1.6 km

1 nautical mile = 1.85 km

_________________________________________________________ Area wise

1 ha = 2.47 acre

1 acre = 4046.86 m²

1 sq m = 10.76 sq. ft

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Volume wise

1 m³= 1ooo litre

1 gallon = 4.54 litre

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Weight wise

1 kg = 1000 gm

1 tonne = 1000 kg

1 quintal = 100 kg

1 pound (lb) = 453.59 gm or 0.453 kg

1 ounce = 25.35 gm

1 stone = 6.35 kg

1 tola = 11.66 gm (but;at present 1 tola gola = 10 gm gold)

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Pressure

1 N/m²= 1 pascal

1 bar = 1 atm = 10⁵N/m²

1 torr = 133.3 N/m²

1 N/mm²= 10 bar

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Speed

1 kmph = 0.27 m/s

1 knot = 0.5144 m/s

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Temperature

C + 273.15 = K

(9C/5) + 32 = F

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****shape wise are volume and other aspects ;

Clear Cover to main reinforcement

Slab = 20 mm

Beam = 25 mm

Column = 40 mm

Footing = 50 mm

Raft Foundation (Bottom And Earth Side) = 75 mm

Raft Foundation (Top) = 50 mm

Staircase = 15 mm

Water Retaining Structure = 20 mm/ 30 mm

Shear wall = 25 mm

Retaining wall = 20 mm ( 25 mm on earth )

Strap Beam = 50 mm

Grade Beam = 20 mm

Flat Slab = 20 mm

{NOTE : Nominal cover (For the purpose of protection against spalling)

For Beam = 40 mm;

For Slab = 35 mm.}

While ;

Minimum nominal cover according to exposure condition,

Mild 25 mm

Moderate 30 mm

Severe 45 mm

Very Severe 50 mm

Extreme 75 mm

Density of Materials

Wood = 500 to 1500 kg/m³

Kerosene = 820 kg/m³

Water = 1000 kg/m³

Cement = 1440 kg/m³

Dry Sand = 1600 kg/m³

River Sand = 1840 kg/m³

Brick = 1700 to 1900 kg/m³

PCC = 2400 kg/m³

RCC = 2500 kg/m³ (in general case)

Glass = +2600 kg/m³

Wrought Iron = 7680 kg/m³

Mild Steel = 7850 kg/m³

Specific Gravity of Materials

Water = 1

Kerosene = 0.8

Mercury = 13.6

Cement = 3.14

Fine Aggregate = 2.48

Coarse Aggregate = 2.71

Fly ash = 2.1

GGBFS = 2.22

Super Plasticizer = 2.1

Pure Bitumen = 0.97 to 1.2

Coal = 1.37 to 1.6

PVC = 1.14

Organic soil = < 2

Nominal Mix Ratio Acc. to grade of Concrete

M25 = 1:1:2 [ Note : M30 and above grade; concrete mix are

M20 = 1:1.5:3 design according to IS 10262. ]

M15 = 1:2:4

M10 = 1:3:6

M7.5 = 1:4:8 (Not used now a days)

Permissible Limit For Solids in water to be used in Construction (Acc to IS 456:2000)

Name Pemissible Limit (max.)

(i) Inorganic 3000 mg/litre

(ii) Organic 200 mg/litre

(iii) Sulphate 400 mg/litre

(iv) Chloride PCC - 2000 mg/litre

RCC - 500 mg/litre

(v) Suspended Matter 2000 mg/litre

Curing Time

Curing is the process in which concrete is protected from the loss of moisture content and kept within a reasonable tamperature range. The result of process increasing the strength and decreasing the permeabilty.Curing is also key player in mitigation crack in the concrete, which severely impacts duribility.

Wet and Damp Condition;

if use OPC = 7 days

PPC = 10 days

Dry and Hot Condition;

if use OPC = 10 days

PPC = 14 days

Membrane Curing a method of curing usually in pavementsby which a material in liquid form is sprayed over the exposed surface shortly after the concrete is finished after which the material solidifies and becomes essentially impervious and thus holds the mixing water in the concrete so that it can hydrate the cement over a period of time.

Steam Curing of concrete is the method of curing the concrete elements in the water vapour. This is used for the enclosed cast-in-place structure and large precast units. In the precast concrete industry. Steam curing allows increased production by a more rapid turnover of models and formwork.