Sand
Gravel
Cement
CONCRETE MIX
4:2:1
4.5M³ CONCRETE
MIX RATIO: 4:2:1
Cement: 1/7 x 4.5m³/0.023=0.643/0.023=27.95 bags=28 bags
Sand: 0.0643x2=1.29m³ round up 1.5m³
Gravel: 0.0643x4=2.57m³ round up to 3m³
Mix gravel: 1.5m³+2.57m³=4.5m³
STEEL ROD LAP
Example: D12 bars in ring beam
Formula
given
Note: steel rods are 6 meters in length,
there they need to join by overlapping
2x24.8 =49.6m (Without lap)
49.6÷6=8.2 i.e. 8 laps
Full length of steel rod
40dx12=480mm or 0.48m
8x0.48m=3.84m
24.9-(0.05+0.05) =24.8
Standard lap Length
49.6+3.84=53.44 =54meters (with lap lengths added)
Prepared by Andrew Araha
50mm cover
SLUMP TEST (CONCRETE)
Process;
1.
2.
3.
4.
5.
Ramp 25 times, refill and compact
25 times, refill cone 25 times
Pour it and place bucket beside it
Measure the distance between that the concrete fall and height of bucket,
If the distance is 80mm, the concrete is 20mpa
Bucket that is
used to mix the
concrete
80mmm
Measure the distance between
highest point of concrete and the
height of bucket, if your
measurement is 80mm, then your
concrete mix is right at 20 MPa
(required)
Concrete poured out
of mixing bucket or
cone
Prepared by Andrew Araha
17 MPA MORTAR TO BLOCK WORK
Mortar Mix Ration: 3:1 (4 parts)
10mm thick mortar bed
150mm
200mm
400mm
200mm
E.g.: Number of concrete blocks: 1500 blocks (150mm or 6” Blocks)
0.6x0.2x0.01=1.2x10-03
1500x1.2x10-03=1.8m3 =2m3
Mortar Mix Ratio: 3:1
Cement: 1/4x2/0.023=0.5/0.023=21.74=22 bags (40kg bag cement)
Sand: 0.5x3=1.5m3 of sand
Prepared by Andrew Araha
BLOCK WORK CORE FILL CONCRETE ESTIMATE
Prepared by Andrew Araha