I will discuss civil engineering basic knowledge. this knowledge is very important for every civil engineering student. if they are working on construction site if they are studying even if they are free so you should learn about the basic knowledge.
#1. Grade Of Concrete
Grade Of Concrete
Mix Ratio
C : S : A
M7.5
1:4:8
M10
1:3:6
M15
1:2:4
M20
1:1.5:3
M25
1:1:2
#2. Unit Weight of Civil Engineering Materials
Materials
Unit Weight (kg/m³)
Cement
1440
P.C.C
2400
R.C.C
2500
Cement Plaster
2000
Bitumen
1340
Glass
2500
Water
1000
#3. Standard Conversion Factor
1 Meter
3.28 feet
1 Meter
39.37 inches
1 Meter
100 cm
1 Meter
1000 mm
1 Foot
12 inches
1 Inch
2.54 cm
1 Inch
8 soot
#4. Clear Cover For Different R.C.C Members
Member
Clear Cover
Foundation
75 mm
Raft Foundation
Top= 50mm
Bottom= 75mm
Sides= 75mm
Strap beam
50mm
Beam
25mm
Column
40mm
Flat Slab
20mm
Slab
15mm
#5. Unit Weight Of Steel per Meters
Diameter of Steel
Weight kg/m
6mm
0.222
8mm
0.395
10mm
0.616
12mm
0.888
16mm
1.578
20mm
2.466
25mm
3.853
#6. Basic Area Units
1 Kanal
20 Marla
1 Marla
272.24 sq. ft.
1 Kanal
502 meter square
1 Marla
25.10 square meter
1 Hectare
10000 sq. m
1 Acre
43560 sq. ft.
#7. Curing of Types of Cement
1. For O.P.C ( ordinary portland cement )
7 Days
2. super sulphate cement
10 Days
3. cement with mineral & admixture
14 Days
#8. Grade of Steel
Tensile Strength
1. Mild Steel
Fe 250
250 N/mm²
2. HYSD ( high yield strength deformed bars )
Fe 415
415 N/mm²
Fe 500
500 N/mm²
3. TMT Bars ( Thermo mechanically treated bars )
Fe 415
415 N/mm²
Fe 500
500 N/mm²
Fe 550
550 N/mm²
#9. Setting Time of Cement
Types of Cement
Initial Setting Time
Final Setting Time
O.P.C ( ordinary portland cement)
30 minutes
600 minutes
Portland blast-furnace cement
30 minutes
600 minutes
RHC ( rapid hardening cement)
30 minutes
600 minutes
LHC ( low heat cement )
60 minutes
600 minutes
#10. Grade of OPC ( ordinary portland cement )
33 Grade
33 N/mm²
43 Grade
43 N/mm²
53 Grade
53 N/mm²
#11. Crushing Strength of Bricks
Types of Brick
Crushing Strength
First Class Brick
105 kg/mm²
2nd Class Brick
70 kg/mm²
3rd Class Brick
35 kg/mm²
#12. Water Absorption of Brick
1st Class Brick
<less than 15% by weight
2nd Class Brick
< less than 20% by weight
3rd Class Brick
> greater than 22% by weight
#13. Water Absorption Of Building Stone
Water absorption of building stone is not greater than 5% by weight.
FAQ or Short Notes:
The weight of 1 bag of cement is 50 kgs.
The density of cement is 1440 kgs/m³
The minimum thickness of the slab should be a minimum of 0.125 meters are 125 millimeters
The fourth one is c/c means central to central distance. so c/c especially we are using in steel structure design for the slab or for any RCC members we can say spacing between two steel rods.
The thickness of DPC dam-proof cores should not be less than 2.5 centimeters or 1 inch.
DL means development length. development length is which makes a good bond between steel and concrete.
The slope of the stair should be between 25 to 40 angles. the riser and stair in between 150 to 200. the trade should be 250 to 300 mm. the vertical portion of the stair is rising.
550 numbers bricks are required in a one-meter cube.
M20 grid concrete is generally used in the construction of slabs. so what is m20 grade concrete m20 means the M20 ratio is 1:1.5:3
Unit weight of steel the formula is D²/162 in kg/m. for example, am using the dia this is steel rod okay which dia is 12 millimeters okay so the formula will be 12*12/162 = 0.88 kg/m
Lapping should not be provided for the dia more than 36 mm.
The maximum free fall height of concrete should not be more than 1.5 meters so the max very far should not be more than 1.5 meters otherwise it will make bleeding, segregation, etc.
The compressive strength of brick is 7.5 N/mm²
The number of bars = length of the opposite side divided by spacing c/c plus 1. then you can find the total numbers of steel rods.
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.
The curing time for concrete members is 7 to 10 days.