a)For 1 m3 f concrete Mix 1:2:4 (M15)
Add 50% for wet concrete=1.50m3
=1.50/(1+2+4)=0.214 m3
For 1m3 =30 bags of cement required (1440/50)Say 30 bags
Cement =0.214X30=6.42 bags
Sand =0.214X2=0.428 m3
Aggregate =0.214X4=0.856 m3
b)Wall Plastering in CM 1:4 of 12mm thick for 100m2
Volume =100 X (12/1000)=1.20 m3
Add 30 to 35% as bulking sand=0.36 m3
Add 20 as wastage of sand =0.312 m3
Total=1.872 m3
=(1.872/1+4)=0.374 m3
Cement = 0.374X30 =10.77 bags
Sand = 0.374X4 = 1.496 m3
c)For 100 m3 of solid Block masonry in CM 1:6 mix 8" thick
Volume =100 X 0.2 (Thickness of wall) = 20 m3
No.of blocks required =20/(0.4 X 0.2 X 0.2)=12502 No's
Volume of mortar = 20-(0.39 X 0.19 X 0.19 X1250)
=20-17.598
=2.40 m3
Note:200mm - 10mm for mortar thickness = 190mm
Blocks = 17.598/(0.4 X 0.2 X 0.2)
=1100 No's
Add 2 % Wastage =22
Total=1122 No's
Increase by 25 % for dry mortar = 3 m3
=3/(1+6)
=0.429 m3
Cement =0.429 X 30 =12.50 bags
Sand =0.429 X 6 =2.57 m3
Blocks =1122 No's
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 M40,target strength is 1.25 X 40 = 50 Mpa
TRAPEZOIDAL FOOTING FORMULA:
Volume V -(L X B X D) =H/3 (A1 + A2 + sq.rt (A1+A2)
where A1= L X B
A2=l X b B
H = D-d (Overall depth of footing - depth of rectangular footing)
THEORETICAL WEIGHT:
Cement | 1440 kg/m3 |
Steel | 7850 Kg/m3 |
Bricks | 1600-1920 Kg/m3 |
1 HP | 745.7 watts |
WEIGHT OF ROD PER METER LENGTH:
6mm | 0.222 |
8mm | 0.395 |
10mm | 0.616 |
12mm | 0.888 |
16mm | 1.578 |
20mm | 2.466 |
25mm | 3.853 |
32mm | 6.313 |
40mm | 9.865 |
CEMENT REQUIREMENTS:
M10 | 210 Kg |
M20 | 320 Kg |
M25 | 340 Kg |
M30 | 380 Kg |
M35 | 410 Kg |
M40 | 430 Kg |
M45 | 450 Kg |
M50 | 450 +M.S 7.5% |
