by Page Contents
1. Mix stipulation for ingredients of concrete
- Grade of Concrete : M50
- Type of Cement : OPC 53 grade confirming to IS 269
- Maximum Nominal Size Aggregate : 20 mm
- Minimum Cement content : 400Kg/cum
- Maximum Water- Cement Ratio : 0.4
- Workability : 125 ± 25 mm (slump)
- Exposure Condition : Moderate for RCC
- 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
2. Material Properties
- Cement : Ultratech OPC 53 grade confirming to IS 269
- Specific Gravity of cement : 3.15
- Chemical Admixture : BASF Master Glenium Sky 8511
- Specific Gravity of Admixture : 1.07
- Specific Gravity
- Coarse aggregate
- 20mm : 2.66
- 12.5mm : 2.64
- Ratio of aggregate: 20mm-50% & 10mm-50%
- Fine aggregate
- Crushed stone aggregate : 2.59
- Water: 1
- Coarse aggregate
- Water Absorption
- Coarse aggregate
- 20mm : 0.37%
- 12.5mm : 0.54%
- Fine aggregate
- Crushed stone aggregate : 2.35%
- Free Surface Moisture
- Fine aggregate : Nil
- Coarse aggregate: Nil
- Sieve Analysis
- Coarse aggregate:
- 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 | 47.505 | 50 | 97.51 |
| 12.5 | 0 | 99.15 | – | 85-100 | 90-100 | 0.00 | 49.575 | 49.58 |
| 10 | 2.54 | 51.07 | 0-20 | 0 – 45 | 40 – 85 | 1.27 | 25.535 | 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 |
- 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 RSand:Msand | Specification | 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 |
All in aggregate:
| IS Seive Sizes | 28.5% | 28.5% | 43% | 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 | 98.58% |
| 4.75 | 0.88 | 0.42 | 100 | 30-50 | 43.37% |
| 0.6 | 0 | 0 | 38.87 | 10-35 | 16.71% |
| 0.15 | 0 | 0 | 9.74 | 0-6 | 4.19% |
3. Target Mean Strength and Mix Proportioning
- As per MORTH the Target Mean Strength for M-50 Grade = 63 Mpa
4. Target Mean Strength and Mix Proportioning
- As per technical specification max Water/Cement + Binder = 0.4
5. Selection of water/Cement Ratio (W/C)
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 )
= 203 lit
Based on trials with super plasticizers, water content reduced by 33%,hence the arrived water content = 135.84lit, So Let us add water 136 lit
6. Cementious content Calculation
Water-Cementitious Ratio = 0.31
Cementious content (Cement OPC 53 ) = 439
Say Cementitious content = 440 kg/m3
Cement = 440 kg/m3
Based on experience and lab trials, Based on experience and lab trials, super plasticizer = 0.57 %
7. Calculation 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= 0.038
Therefore , corrected proportion = 0.658
Adjust for pumpability , i.e decrese by 10% = 0.59 %
Based on experience Considering Volume of coarse aggregate = 0.57
Therefore, Volume of Fine aggregate = 0.43
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 = 0.1397 m3
c) Volume of water = (Mass of water /specific gravity of water)× 1000 = 0.136 m3
d) Volume of admixture = (Mass of admixture /specific gravity of admixture)× 1000 = 0.00234 m3
e) Volume of all in aggregate =[a-(b+c+d)] = 0.72 m3
f) Mass of coarse aggregate(CA)
1) 20 mm = e × volume of CA × sp. gravity × % of 20mm × 1000 = 0.72*0.57*2.65*0.5*1000 = 545.27 kg/m3, Say 545 kg/m3
2) 12 mm = e× volume of CA × sp. gravity × % of 12mm × 1000 = 0.72*0.57*2.63*0.5*1000 = 541.16 kg/m3, Say 541 kg/m3
g) Mass of Fine aggregate = e × volume of FA × sp. gravity × 1000 0.72*0.43*2.59*1000 = 804.06 kg/m3 Say 804 kg/m3
9. Details of Mix Design
- cement = 440 kg
- 20mm = 545 kg
- 12mm = 541 kg
- Crushed stone sand = 804 kg
- Chemical admixture = 2.51 kg
- Free Water = 136 kg
- Water-Cement Ratio = 0.31
- Concrete density = 2469 kg/m3
