M30 Concrete Mix Design as per IS 10262:2019: Worked Example

Introduction

Concrete mix design is the process of selecting suitable quantities of cement, water, fine aggregate, coarse aggregate, chemical admixture and entrapped air to produce concrete with the required strength, durability and workability.

This article presents a corrected illustrative mix design for M30 concrete using IS 10262:2019 and the durability requirements of IS 456:2000.

The calculation is based on the following example:

• Grade of concrete: M30
• Exposure condition: Moderate
• Nominal maximum aggregate size: 20 mm
• Aggregate type: Angular crushed aggregate
• Fine aggregate: Grading Zone III
• Cement: OPC 43 grade
• Placement: Pumped concrete
• Required slump: 75 mm at the point of placement
• Chemical admixture: ECMAS HP 890
• Site control: Good
• No supplementary cementitious material is considered

This is a preliminary trial mix. The final mix must be confirmed through laboratory and field trials using the actual cement, aggregates, admixture, batching plant and placing conditions.

Applicable Codes and References

The following standards are used:

1. IS 10262:2019, Concrete Mix Proportioning—Guidelines.
2. IS 456:2000, Plain and Reinforced Concrete—Code of Practice.
3. IS 383:2016, Coarse and Fine Aggregate for Concrete—Specification.
4. IS 9103, Chemical Admixtures for Concrete.
5. IS 269:2015, Ordinary Portland Cement—Specification, as applicable to the cement manufacturer’s certificate.
6. ECMAS HP 890 product technical data sheet.

The following IS 10262:2019 provisions are used:

• Clause 4.2 and Tables 1 and 2: Target mean strength
• Clause 5.1 and Figure 1: Selection of water-cement ratio
• Table 3: Entrapped air
• Clause 5.3 and Table 4: Water and admixture content
• Clause 5.4: Cement content
• Clause 5.5 and Table 5: Coarse aggregate proportion
• Clause 5.7: Absolute-volume method
• Clause 5.8: Trial mixes

1. Design Data and Assumptions

For moderate exposure, IS 456:2000 Table 5 specifies a maximum free water-cement ratio of 0.50 and a minimum cement content of 300 kg/m³ for reinforced concrete. The values 0.45 and 320 kg/m³ apply to severe exposure.

Parameter	Adopted value
Grade	M30
Characteristic compressive strength, (f_{ck})	30 MPa
Exposure	Moderate
Nominal maximum aggregate size	20 mm
Aggregate shape	Angular
Fine aggregate grading zone	Zone III
Cement type	OPC 43 grade
Specific gravity of cement	3.16
Specific gravity of fine aggregate	2.72
Specific gravity of coarse aggregate	2.66
Fine aggregate absorption	2.0%
Fine aggregate moisture content	2.0%
Coarse aggregate absorption	0.5%
Coarse aggregate moisture content	0%
Selected slump	75 mm
Entrapped air	1.0%
Chemical admixture	ECMAS HP 890
Assumed admixture dosage	1.1% by mass of cement
Specific gravity of HP 890	1.07
Assumed water reduction	20%
Standard deviation	5.0 MPa
Pump adjustment to coarse aggregate	10% reduction for preliminary trial

All aggregate quantities calculated below are initially reported on a saturated surface-dry, or SSD, basis.

The moisture correction must be performed again at the batching plant using actual moisture test results.

2. Target Mean Compressive Strength

According to IS 10262:2019, the target mean strength is calculated as:

f’ck = fck + 1.65 s
f’ck = fck + X

For M30 concrete:

Method 1: f’ck = 30 + 1.65 × 5 = 30 + 8.25 = 38.25 MPa
Method 2: f’ck = 30 + 6.5 = 36.50 MPa

IS 10262:2019 also requires the alternative expression:

f’t = f{ck} + X

For M30 concrete, the value of (X) is 6.5 MPa.

f’t = 30 + 6.5 = 36.50 MPa

Therefore, the target mean compressive strength is the greater of the two values:

f’t = max(38.25, 36.50)

f’t = 38.25 MPa
The value (S=5.0) MPa is an assumed standard deviation for this initial calculation. If at least 30 valid strength results are available for similar concrete, the actual standard deviation should be calculated and used.

3. Selection of Water-Cement Ratio

3.1 Strength requirement

For OPC 43 grade cement, IS 10262:2019 Figure 1 permits the use of Curve 2 when actual 28-day cement strength data is not available.

Reading the curve for a target concrete strength of approximately 38.25 MPa gives a preliminary free water-cement ratio of approximately:

(w/c) strength ≈ 0.43

This value is an approximate graphical reading. It is not a fixed tabulated value and must be verified by trial mixes.

If actual 28-day cement strength data is available, the appropriate curve should be selected based on that strength. You can check out the detailed guide on water-cement ratio.

3.2 Durability requirement

For reinforced concrete with 20 mm nominal maximum aggregate size, IS 456:2000 Table 5 gives:

Exposure condition	Minimum grade	Maximum free w/c	Minimum cement
Moderate	M25	0.50	300 kg/m³
Severe	M30	0.45	320 kg/m³

The specified grade is M30, which is greater than the minimum grade required for moderate exposure.

The strength-based w/c ratio is 0.43, and the durability limit is 0.50.

Therefore:

(w/c) adopted = min(0.43, 0.50)

(w/c) adopted = 0.43

The value 0.45 and minimum cement content of 320 kg/m³ correspond to severe exposure, not moderate exposure.

Important note about admixture

The addition of a superplasticiser does not automatically reduce the w/c ratio by 0.05.

The correct procedure is:

1. Select the preliminary w/c ratio from strength and durability requirements.
2. Use the admixture to reduce water demand while maintaining the required slump.
3. Confirm the actual water reduction through trials.
4. Maintain the selected w/c ratio unless the design is deliberately revised and rechecked.

For this example, a 20% water reduction is assumed for the preliminary trial. This is not a guaranteed value. Please refer to our guide on the slump test.

4. Selection of Water Content

IS 10262:2019 Table 4 gives a water content of:

186 kg/m³
for 20 mm angular aggregate at 50 mm slump.

The selected slump is 75 mm. IS 10262 permits approximately 3% adjustment for every 25 mm change in slump.

Therefore:

W₇₅ = 186(1 + 0.03)
W₇₅ = 191.58 kg/m³

Thus, the estimated water content before admixture reduction is:

W₇₅ = 191.6 kg/m³

The value 197 kg/m³ is approximately obtained by applying a 6% increase:

186(1 + 0.06) = 197.16 kg/m³

This corresponds approximately to a 100 mm slump, not a 50–75 mm slump.

Water reduction using superplasticiser

Assume that ECMAS HP 890 provides a 20% reduction in water demand at the selected trial dosage.

W_trial = 191.58 × (1 − 0.20)

W_trial = 153.264 kg/m³

Adopt:

W = 153.3 kg/m³

The 20% reduction must be confirmed using the actual cement and aggregates. If the trial does not achieve the required slump or workability retention, the water and admixture quantities must be adjusted.

Sl. No. (1)	Nominal Maximum Size of Aggregate (mm) (2)	Water Content1 (kg) (3)
i)	10	208
ii)	20	186
iii)	40	165

¹⁾ Water content corresponding to saturated surface dry aggregate.

5. Calculation of Cement Content

The cement content is calculated from:

C = W / (w/c)

C = 153.264 / 0.43

C = 356.43 kg/m³

Adopt:

C = 356.4 kg/m³

Durability check

• Minimum cement for moderate exposure = 300 kg/m³
• Calculated cement content = 356.4 kg/m³

Therefore:

356.4 > 300

The durability minimum is satisfied.

The calculated cement content is also below the 450 kg/m³ limit normally referenced under IS 456:2000 Clause 8.2.4.2.

6. Chemical Admixture Content

Assume ECMAS HP 890 dosage:

Admixture dosage = 1.1% of cement mass

M adm = 0.011 × 356.43

M adm = 3.92 kg/m³

Adopt:

M adm = 3.9 kg/m³

The manufacturer’s technical data gives a typical dosage range of approximately 0.3% to 1.5% by mass of cement and a specific gravity of approximately 1.07 at 27°C. The final dosage must be determined by trials.

The 1.1% dosage is an assumption for this worked example. It is not a fixed value required by IS 10262:2019.

7. Coarse Aggregate Proportion

IS 10262:2019 Table 5 gives the following coarse aggregate volume fraction at a water-cement ratio of 0.50:

For 20 mm angular aggregate and Zone III fine aggregate:

V_CA=0.64

The value 0.62 applies to Zone II fine aggregate, not Zone III.

Adjustment for w/c ratio

The selected w/c ratio is 0.43, which is 0.07 lower than 0.50.

IS 10262 permits an increase of 0.01 in the coarse aggregate fraction for every 0.05 decrease in w/c ratio.

V CA = 0.64 + ((0.50 − 0.43) / 0.05) × 0.01

V CA = 0.64 + 0.014

V CA = 0.654

Therefore, before the pump adjustment:

V CA = 0.654

Adjustment for pump placement

For pumped concrete, IS 10262 permits the estimated coarse aggregate content to be reduced by up to 10%, provided that strength, workability and durability requirements are satisfied.

For this preliminary pumpable trial, assume a 10% reduction:

V CA, pump = 0.654 × (1 − 0.10)

V CA, pump = 0.5886

The fine aggregate fraction is:

V FA = 1 − 0.5886

V FA = 0.4114

Therefore:

V CA = 0.5886

V FA = 0.4114

The 10% pump adjustment is optional and must be confirmed by trial batches. If the trial mix is sufficiently workable without this adjustment, the unadjusted value of 0.654 may be used and the aggregate quantities recalculated.

8. Absolute-Volume Calculation

The absolute-volume method is used to calculate the quantities of fine and coarse aggregate.

8.1 Absolute volume of cement

V c = 356.43 / (3.16 × 1000)

V c = 0.11279 m³

8.2 Absolute volume of water

V w = 153.264 / (1.00 × 1000)

V w = 0.153264 m³

8.3 Absolute volume of admixture

V adm = 3.92 / (1.07 × 1000)

V adm = 0.003664 m³

8.4 Volume of entrapped air

For 20 mm aggregate, adopt 1% entrapped air:

V air = 0.01 m³

8.5 Volume of total aggregate

V_agg = 1 − (V c + V w + V adm + V air)

V_agg = 1 − (0.11279 + 0.153264 + 0.003664 + 0.010)

V_agg = 0.720282 m³

8.6 Coarse aggregate quantity

M_CA = V agg × V CA × SG CA × 1000

M_CA = 0.720278 × 0.5886 × 2.66 × 1000

M_CA = 1127.7 kg/m³

Adopt:

M_CA = 1128 kg/m³

8.7 Fine aggregate quantity

V_agg × V_FA × SG_FA × 1000

M_FA = 0.720278 × 0.4114 × 2.72 × 1000

M_FA = 806.0 kg/m³

Adopt:

M_FA = 806 kg/m³

9. Absolute-Volume Summary

Material	Quantity	Specific gravity	Absolute volume
Cement	356.43 kg	3.16	0.11279 m³
Water	153.264 kg	1.00	0.153264 m³
ECMAS HP 890	3.92 kg	1.07	0.003664 m³
Fine aggregate, SSD	806.0 kg	2.72	0.296322 m³
Coarse aggregate, SSD	1127.7 kg	2.66	0.423956 m³
Entrapped air	—	—	0.010000 m³
Total	—	—	1.000000 m³

The calculation confirms that the total volume is approximately 1.00 m³.

Because the admixture is a liquid product, the supplier’s declared water contribution should be included in the final batch calculation. Any water carried by the admixture must be deducted from the separately added water so that the total free water does not exceed the adopted design value.

10. Preliminary Mix Proportions per Cubic Metre

The calculated preliminary trial mix is:

Material	Quantity per m³
Cement	356 kg
Total design water allowance	153 kg
Fine aggregate, SSD	806 kg
Coarse aggregate, SSD	1128 kg
ECMAS HP 890	3.9 kg
Entrapped air	Approximately 1%
Adopted free w/c ratio	0.43

The approximate mass ratio is:

Cement : Fine aggregate : Coarse aggregate = 1 : 2.26 : 3.16

w/c = 0.43

Admixture dosage = 1.1% by mass of cement

The ratios check out against your masses: 806 / 356.4 = 2.26 for fine aggregate and 1128 / 356.4 = 3.165 for coarse aggregate, which rounds to 3.16 (or 3.17 if you round normally; 3.16 comes from using 356.43 and 1127.7).

Final mix per m³ of concrete:

• Cement = 356.4 kg
• Water = 153.3 kg
• Fine aggregate = 806 kg
• Coarse aggregate = 1128 kg
• Superplasticiser = 3.9 kg

Total mass = 356.4 + 153.3 + 806 + 1128 + 3.9 = 2447.6 kg/m³, which is a reasonable fresh density for this type of mix.

This ratio is only a preliminary trial proportion. It should not be treated as a final approved site mix without test results.

11. Moisture Corrections at the Batching Plant

The above aggregate quantities are on an SSD basis. Actual aggregate stockpiles may be wet, saturated, surface-dry or partially dry.

If moisture content and absorption are expressed as percentages of oven-dry aggregate mass, the wet batch mass may be estimated from: M_wet = M_SSD × (100 + M) / (100 + A)

where:

• M_wet = aggregate mass to be batched
• M_SSD = SSD aggregate mass from the mix design
• M = actual total moisture content (%)
• A = absorption (%)

Water to be added = W − Σ [M_SSD × (M − A) / (100 + A)]

If the aggregate is drier than SSD, the value of W_free becomes negative and additional water is required.

For the assumed fine aggregate:

• Moisture content = 2.0%
• Absorption = 2.0%

The fine aggregate is approximately at SSD condition and contributes approximately no free water.

For the assumed coarse aggregate:

• Moisture content = 0%
• Absorption = 0.5%

The coarse aggregate is drier than SSD. The SSD coarse aggregate quantity of approximately 1128 kg/m³ corresponds to approximately 1122 kg/m³ of dry aggregate, with an approximate absorption demand of 5.6 kg/m³.

Actual daily moisture test results must be used for batching.

12. Trial Mix Procedure

IS 10262:2019 requires the calculated mix proportions to be checked using trial batches.

Trial Mix 1

Prepare the calculated mix and measure:

• Slump
• Slump retention
• Segregation
• Bleeding
• Finishability
• Air content
• Concrete temperature
• Density or yield

If the measured workability is different from the specified value, adjust the water and/or admixture content.

Trial Mix 2

Recalculate the mix while maintaining the selected free w/c ratio of 0.43.

The adjusted mix should again be checked for workability and fresh-concrete properties.

Trial Mixes 3 and 4

Prepare additional trials using the same water content as Trial Mix 2, with the w/c ratio varied by approximately ±10%.

The trial batches should be produced using the same equipment, mixing sequence, aggregate moisture condition and placing method intended for the project.

The final mix should be selected only after reviewing:

• 7-day compressive strength
• 28-day compressive strength
• Workability
• Slump retention
• Segregation and bleeding
• Pumpability
• Surface finish
• Variability of test results

13. IS 10262:2019 Figure 1

The original IS 10262:2019 Figure 1 contains three curves for different expected 28-day cement strengths.

The figure should be reproduced only in accordance with the applicable BIS copyright and permission requirements. The original background and all three curves should remain unchanged.

For this example, the design point may be identified separately as:

• Target concrete strength = approximately 38.25 MPa
• Preliminary free w/c ratio = approximately 0.43
• Cement curve = Curve 2 for OPC 43 when actual cement strength data is unavailable

The point (38.25\text{ MPa}, 0.43) is an approximate graphical reading and should not be presented as a separate code-mandated value.

Suggested figure caption:

Figure 1. Relationship between free water-cement ratio and 28-day compressive strength for cements of different expected strengths, reproduced from IS 10262:2019 Figure 1. The highlighted point is an approximate reading used for this illustrative M30 mix design.

14. Final Result

M30 Concrete Mix Proportion for 1 m³

For the stated assumptions, the preliminary M30 mix per cubic metre is:

• Cement = 356 kg
• Water = 153 kg
• Fine aggregate = 806 kg
• Coarse aggregate = 1128 kg
• ECMAS HP 890 = 3.9 kg
• w/c = 0.43

M30 Concrete Mix Proportion for 1 m³

Material	Quantity for 1 m³	Ratio or dosage
Cement	356.4 kg	1.00
Fine aggregate	806.0 kg	2.26
Coarse aggregate	1,128.0 kg	3.16
Effective free water	153.3 L	w/c = 0.43
ECMAS HP 890 admixture	3.9 kg	1.1% of cement

Final mix proportion by mass:

Cement : Fine aggregate : Coarse aggregate = 1 : 2.26 : 3.16

Water–cement ratio = 0.43

and HP 890 dosage of approximately 1.1% by mass of cement.

Recommended Reading: M40 Concrete Mix Design as per IS 10262:2019: A Detailed Worked Example

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FAQs:

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References:

1. Duggal, S.K. (2008). Building material. New Age International (P) Ltd., Publishers
2. Bureau of Indian Standards. (2019). Concrete Mix Proportioning—  Guidelines. (IS 10262- 2019). Bureau of Indian Standards (BIS
3. Bureau of Indian Standards. (2000). Plain and Reinforced Concrete: — Code of Practice (IS 456: 2000) (Fourth Revision). Bureau of Indian Standards (BIS).