Page Contents
1. Mix stipulation for ingredients of concrete
- Grade of Concrete : M55
- Type of Cement : OPC 53 grade confirming to IS 269
- Maximum Nominal Size Aggregate : 20 mm
- Minimum Cement content : 380Kg/cum
- Maximum Water- Cement Ratio : 0.4
- Workability : 125± 25 mm (slump)
- Exposure Condition : Moderate (For Reinforced Concrete)
- Method of Concrete Placing : Pumping or Bucket
- Degree of Supervision : Good
- Type of Aggregate : Crushed angular Aggregate
- Chemical admixture type : Super plasticizers Confirming IS 9103:1999
- Max cement content: 450kg/cum
2. Material Properties
- Cement : Ultratech OPC 53 grade confirming to IS 269
- Specific Gravity of cement : 3.15
- Chemical Admixture : Fosroc Auromix 400
- Specific Gravity of Admixture : 1.09
- Specific Gravity
- Coarse aggregate
- 20mm : 2.69
- 12.5mm : 2.69
- Ratio of aggregate: 20mm-50% & 12.5mm-50%
- Fine aggregate
- Crushed stone aggregate : 2.6
- Coarse aggregate
- Water: 1
- Water Absorption
- Coarse aggregate
- 12.5mm : 0.54%
- 20mm : 0.37%
- Fine aggregate
- Crushed stone aggregate : 2.35%
- Coarse aggregate
- Free Surface Moisture
- Fine aggregate : Nil
- Coarse aggregate: Nil
- Sieve Analysis
- Coarse aggregate:
IS Seive Sizes | % Passing | IS Requirement as per IS 383 Table 2 | Ratio | Confirming to IS 383 table 2 | |||||||
Single Sized | Graded | 50% | 50% | ||||||||
20 mm | 12.5 mm | 20 mm | 12.5 mm | 20 mm | 12.5 mm | Combined 100% | |||||
20 | 95.01 | 100 | 85-100 | 100 | 100 | 47.51 | 50 | 97.51 | |||
12.5 | 0 | 99.15 | – | 85-100 | 90-100 | 0.00 | 49.58 | 49.58 | |||
10 | 2.54 | 51.07 | 0-20 | 0 – 45 | 40 – 85 | 1.27 | 25.54 | 26.81 | |||
4.75 | 0.88 | 0.42 | 0-5 | 0-10 | 0 – 10 | 0.44 | 0.21 | 0.65 | |||
PAN | 0 | 0 | – | – | – | 0 | 0 | 0 |
Sieve Analysis of Coarse Aggregate, M55 grade of concrete
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- Fine Aggregate: Confirming to grading Zone II of table 4 of IS 383 Note:- as per field trials for pumpable concrete fine aggregate should pass zone II; According to IS 383 clause No. 31.2.2 allows to use crushed stone sand as fine aggregate for concrete .According to IS 383-2016 for crushed stone sand, the permeassible limit on 150 micron IS sieve is increased to20%.
IS Seive Sizes | % Passing | Ratio River Sand:Msand | 0 | Combined Passing | |||||
0 | 1 | IS 383 Zone II | |||||||
R Sand | M Sand | R Sand | M Sand | ||||||
4.75 | 0 | 100 | 0 | 100 | 90-100 | 100 | |||
2.36 | 0 | 85.88 | 0 | 85.88 | 75-100 | 85.88 | |||
1.18 | 0 | 58.95 | 0 | 58.95 | 55-90 | 58.95 | |||
600 | 0 | 38.87 | 0 | 38.87 | 35-59 | 38.87 | |||
300 | 0 | 21.47 | 0 | 21.47 | 8-30 | 21.47 | |||
150 | 0 | 9.74 | 0 | 9.74 | 0-10 | 9.74 |
Sieve Analysis of Fine Aggregate, M55 grade of concrete
All in aggregate:
IS Seive Sizes | 29.5% | 29.5% | 41% | Specification | Combined Passing | |||
20mm | 12.5mm | c sand | min-max | |||||
40 | 100 | 100 | 100 | 100-100 | 100.00% | |||
20 | 95.01 | 100 | 100 | 95-100 | 98.53% | |||
4.75 | 0.88 | 0.42 | 100 | 30-50 | 41.38% | |||
0.6 | 0 | 0 | 38.87 | 10-35 | 15.94% | |||
0.15 | 0 | 0 | 9.74 | 0-6 | 3.99% |
Sieve Analysis of All in Aggregate, M55 grade of concrete
3. Target Mean Strength
- As per MORTH the Target Mean Strength for M55 Grade = 55+14=69Mpa
4. Selection of water/Cement Ratio (W/C)
- As per the specification max Water/Cement + Binder = 0.4
5. Water content Calculation
Ref Tab 2 , IS 10262 , Maximum water content per cum for 20mm Aggregate = 186 litre for 50 mm slump
= 186 + (0.09 * 186) (add 3% for every 25 mm increase )
= 203lit
Based on trials with super plasticizers, water content reduced by 26%,hence the arrived water content = 150.03lit, So Let us add water 150 lit
6. Cementious content Calculation
Based on experience adopt Water-Cementitious Ratio = 0.34
Cementious content (Cement OPC 53 ) = 441.2
Say Cementitious content = 445 kg/m3
Cement = 445 kg/m3
Based on experience and lab trials, Based on experience and lab trials, super plasticizer = 0.6 %
7. Aggregate content Calculation
Ref Tab 3 of IS 10262 , for Sand Zone II , volume of coarse aggregate
per unit vol of total aggregate for 0.5 water-cement ratio = 0.62
Adjust for W/c ratio : Add @ 0.01 for every decrease in 0.05= 0.032
Therefore , corrected proportion = 0.652
Adjust for pumpability , i.e. decrease by 10% = 0.59 %
Based on experience Considering Volume of coarse aggregate = 0.59
Therefore, Volume of Fine aggregate = 0.41
8. Mix volume Calculation per cubic meter of concrete
a) Volume of concrete = 1 m3
b) Volume of cement = (Mass of cement /specific gravity of cement) × 1000 =445/(3.15×1000)= 0.1413 m3
c) Volume of water = (Mass of water /specific gravity of water)× 1000 = 0.150 m3
d) Volume of admixture = (Mass of admixture /specific gravity of admixture)× 1000 = (445×0.6)/(100×1.09×1000)=0.00245 m3
e) Volume of all in aggregate =[a-(b+c+d)] =1-(0.1413+0.150+0.00245)=0.706
f) Mass of coarse aggregate(CA)
1) 20 mm = e × volume of CA × sp. gravity × % of 20mm × 1000 = 0.706*0.59*2.69*0.5*1000= 560.47kg/m3, Say 561 kg/m3
2) 12 mm = e× volume of CA × sp. gravity × % of 12mm × 1000 = 0.706*0.59*2.69*0.5*1000 = 560.47 kg/m3 Say 560 kg/m3
g) Mass of Fine aggregate = e× volume of FA × sp. gravity × 1000 =0.706*0.41*2.6*1000= 752.9kg/m3 Say 753 kg/m3
9. Details of Mix Design
- cement = 445 kg
- 20mm = 561 kg
- 12mm = 560 kg
- Crushed stone sand = 753 kg
- Chemical admixture = 2.67 kg
- Free Water = 150 kg
- Water-Cement Ratio = 0.34
- Concrete density = 2472 kg/m3