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Standard Overview
IS 10262:2019 — Guidelines for Concrete Mix Proportioning · Fifth Revision · Bureau of Indian Standards
IS 10262 is the primary Indian Standard governing the design of concrete mix proportions. Originally published in 1982, the current edition — the Fifth Revision (2019) — replaces IS 10262:2009 and incorporates significant updates to accommodate modern materials, admixtures, supplementary cementitious materials (SCMs) and high-performance concrete.
📌 Standard Identity
- Full title: IS 10262:2019 — Concrete Mix Proportioning: Guidelines (Fifth Revision)
- Issuing body: Bureau of Indian Standards (BIS), Manak Bhavan, New Delhi
- Technical committee: CED 2 — Cement and Concrete Sectional Committee
- Supersedes: IS 10262:2009 (Fourth Revision)
- Used in conjunction with: IS 456:2000, IS 383:2016, IS 9103:1999, IS 15388, IS 3812, IS 16714
- Scope: Normal concrete M10–M55; guidance for higher grades; ordinary and special exposure conditions
- Exclusions: Lightweight concrete, heavyweight concrete, fibre-reinforced concrete, roller-compacted concrete (separate guidance required)
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Document Structure — IS 10262:2019
Clauses, tables, figures and annexes of the standard
| Clause / Annex | Title | Key Content |
|---|
| Cl. 1 | Scope | Applicability to ordinary and special structural concrete; grade M10 to M55 |
| Cl. 2 | References | IS 456, IS 383, IS 9103, IS 1489, IS 3812, IS 15388, IS 516, IS 2386 and others |
| Cl. 3 | Terminology | Definitions: characteristic strength, target mean strength, standard deviation, water-cement ratio, etc. |
| Cl. 4 | Stipulations for Proportioning | Data requirements before design: grade, cement type, MSA, workability, exposure class, aggregate type, grading zone, quality control level |
| Cl. 5 | Mix Proportioning | Core nine-step design procedure: TMS (5.3), w/c (5.6), water (5.4), cement (5.5), aggregates (5.8); Table references throughout |
| Cl. 5.7 | SCM Addition | k-factor method for fly ash (k=0.25), GGBS (k=0.60), silica fume (k=2.50); effective w/c calculation |
| Cl. 6 | Workability | Slump selection guide by application; relationship with water content |
| Cl. 7 | Quality Control | SD selection; production monitoring requirements; relationship with IS 456 Cl. 15 |
| Cl. 8 | Admixtures | Use of WRAs, HRWRAs (SP), retarders, accelerators in mix design; IS 9103 reference; water reduction methods |
| Cl. 9 | Trial Mix | Mandatory trial programme; minimum 3 batches; acceptance criteria; 28-day strength requirement; fresh concrete testing |
| Table 1 | Standard Deviation | Assumed SD by grade range: M10–15 (3.5 MPa), M20–25 (4.0 MPa), M30–55 (5.0 MPa) |
| Table 2 | Water Content | Design water (L/m³) by MSA (10/20/40mm) and slump (25–150mm) for crushed aggregate |
| Table 3 | Volume Fraction (jc) | CA volume fraction by MSA (10/20/40mm), FA zone (I–IV) and aggregate type (crushed/rounded) |
| Figure 1 | Strength vs w/c Curves | 28-day cube strength vs w/c ratio for OPC 33, OPC 43, OPC 53 and PPC |
| Annex A | Moisture Correction | Daily batch water and aggregate mass correction for field moisture conditions |
| Annex B | Worked Example | Complete illustrative example for M30 concrete |
| Annex C | High-Performance Concrete | Guidance notes for M60+ and HPC; silica fume and HRWRA requirements |
4
Clause 4 — Stipulation of Proportioning
Data requirements before mix design calculations can begin
IS 10262:2019 Cl. 4.1
Grade Designation
The grade of concrete shall be specified by its characteristic compressive strength fck measured on 150 mm cubes at 28 days, in accordance with IS 456 Table 2. The grade designation (e.g. M30) means fck = 30 MPa. The mix designer shall not target fck directly — the Target Mean Strength (TMS) is calculated per Cl. 5.3 to ensure statistical compliance.
IS 10262:2019 Cl. 4.2
Type and Grade of Cement
Cement type determines which strength-w/c curve (IS 10262 Figure 1) is used. The four cement types with Figure 1 curves are OPC 33, OPC 43, OPC 53 and PPC. For other cements (PSC IS 455, Low Heat IS 12600, SRPC IS 12330), the designer shall establish the strength-w/c relationship by trial — no Figure 1 curve is provided for these cements. The cement grade also determines the TMS achievable at practical w/c ratios; lower grades require lower w/c to achieve high fck, potentially making some grades economically unsuitable for high-strength concrete.
IS 10262:2019 Cl. 4.3
Maximum Nominal Aggregate Size
The maximum aggregate size (MSA) shall satisfy all three IS 456 Cl. 26.4 criteria simultaneously: (a) ≤ 1/4 of the minimum section dimension; (b) ≤ 3/4 of minimum clear spacing between bars; (c) ≤ 3/4 of nominal cover. The MSA directly determines which row of IS 10262 Table 2 (water content) and Table 3 (jc values) is used. A 40 mm MSA achieves 5–10% reduction in water demand over 20 mm, improving economy.
IS 10262:2019 Cl. 4.4
Workability
Target slump (in mm) shall be specified for the placement condition. IS 10262 Cl. 5.4 gives guidance: 25–50 mm for mass concrete and roads; 75–100 mm for general structural concrete; 100–150 mm for pumped or highly reinforced concrete. The target slump determines which column of Table 2 is used. Higher target slump requires more water (and hence more cement at constant w/c).
IS 10262:2019 Cl. 4.5
Degree of Supervision and Quality Control
Determines whether IS 10262 Table 1 assumed standard deviations are used (initial design without production data) or actual σ from ≥30 test results (mature production). Quality control level also links to IS 456 Cl. 15 acceptance criteria for ongoing production monitoring.
5
Clause 5 — Mix Proportioning Procedure
The nine calculation steps at the core of IS 10262:2019
IS 10262:2019 Cl. 5.3 — Target Mean Strength
fcr = fck + 1.65 × S
The margin 1.65 × S corresponds to a 5% defect rate (one-tailed 95th percentile of the standard normal distribution). For initial designs without production data, S is taken from IS 10262 Table 1. When ≥30 cube results are available, actual S shall be computed and used if higher than the Table 1 value.
IS 10262:2019 Cl. 5.6 — Water-Cement Ratio
Adopt min(w/c from Figure 1, IS 456 Table 5 maximum)
Two independent constraints are evaluated. The strength-based w/c is read from IS 10262 Figure 1 for the design TMS and cement grade. The durability-based maximum is read from IS 456 Table 5 for the exposure class. The lower value is adopted. IS 10262 Cl. 5.6 explicitly states that the value from Figure 1 shall be checked against IS 456 Table 5 and the lower value adopted.
IS 10262:2019 Cl. 5.4 — Water Content
W = IS 10262 Table 2 value × adjustments
Table 2 gives water content for crushed aggregate only. Rounded aggregate deducts 10 L/m³. Superplasticiser reduces water by the WR percentage of the admixture. Admixture water reduction must be verified by trial — Table 2 values assume no admixture. Note: Table 2 is the starting point; actual water demand must be verified in the trial mix stage as it depends on aggregate surface texture, shape, absorption and grading — all variable between sources.
IS 10262:2019 Cl. 5.5 — Cement Content
C = W / (w/c) · IS 456 Cl. 8.2.4 applies
Cement content is derived — not independently chosen. After computing C = W/(w/c), it must be checked against IS 456 Table 5 minimum for the exposure class and the IS 456 Cl. 8.2.4.2 maximum of 450 kg/m³. If C < minimum: increase to minimum. If C > 450: the mix design is non-compliant and a superplasticiser must be introduced to reduce W, and hence C.
IS 10262:2019 Cl. 5.7 — SCM Addition (New in 2019)
Effective w/c = W / (C + k × f)
Supplementary cementitious materials improve durability performance beyond what the simple w/c ratio captures. The k-factor system weights each SCM by its cementitious efficiency: fly ash k=0.25 (slow pozzolanic reaction), GGBS k=0.60 (moderate latent hydraulic), silica fume k=2.50 (very high pozzolanic reactivity). The effective w/c, not the simple w/c, is used to check IS 456 Table 5 durability compliance when SCMs are present. This clause was substantially revised in 2019 to formalise SCM usage.
IS 10262:2019 Cl. 5.8 — Aggregate Proportioning
Absolute Volume Method
CA mass = jc × DRBD (IS 10262 Table 3). FA mass is then the balance from the absolute volume equation: 1 m³ = volume of (cement + water + CA + FA + air + SCMs). This method ensures physical consistency — all constituents must physically occupy 1.000 m³. Any design where the FA volume is negative is physically impossible and must be revised.
T1
IS 10262:2019 Table 1 — Standard Deviation
Assumed standard deviation for initial mix design when production data is unavailable
| Grade Range | Grades Included | Assumed S (MPa) | Margin 1.65×S (MPa) | TMS = fck + Margin |
|---|
| M10 to M15 | M10, M15 | 3.5 | 5.78 | fck + 5.78 |
| M20 to M25 | M20, M25 | 4.0 | 6.60 | fck + 6.60 |
| M30 to M55 | M30, M35, M40, M45, M50, M55 | 5.0 | 8.25 | fck + 8.25 |
⚠️ Important Limitation of Table 1: These assumed values apply only to the initial design before production data is collected. For M55 and higher grades, the actual standard deviation in production often exceeds 5.0 MPa, making the assumed value unconservative. For HSC (M50+), use actual production σ as soon as 30 results are available. Starting with an assumed σ of 5.5–6.0 MPa provides additional safety margin for initial HSC trials.
T2
IS 10262:2019 Table 2 — Water Content
Approximate water content (L/m³) for crushed aggregate concrete · IS 10262:2019 Table 2
| Maximum Aggregate Size |
25 mm Slump |
50 mm Slump |
75 mm Slump ★ |
100 mm Slump |
125 mm Slump |
150 mm Slump |
| 10 mm |
208 | 212 | 220 | 228 | 234 | 242 |
| 20 mm ★ |
175 | 180 | 186 ★ | 194 | 200 | 208 |
| 40 mm |
159 | 163 | 168 | 175 | 180 | 188 |
All values in L/m³. Applicable to crushed (angular) aggregate, Zone II fine aggregate, OPC cement. Apply corrections for rounded aggregate (−10 L/m³), superplasticiser, and M-Sand (+5 to +12 L/m³).
Table 2 — Detailed Notes
Crushed vs Rounded Aggregate
Table 2 values apply strictly to crushed angular aggregate. For rounded (river gravel) aggregate, subtract 10 L/m³ from the Table 2 value. This correction reflects the lower surface area and smoother particle surfaces of rounded aggregate, which require less paste for lubrication. Mixed aggregate (combination of crushed and rounded) requires interpolation — typically 0–8 L/m³ adjustment depending on blend ratio.
Superplasticiser Adjustment
When a superplasticiser is used, the water content is reduced by the documented water reduction percentage of the admixture: W_design = W_Table2 × (1 − WR%/100). The WR% must be verified by trial for the specific cement + admixture combination — saturated dosage, cement alkali content and temperature all influence actual WR%. The Table 2 value is the starting point before SP reduction; it does not account for SP.
Fine Aggregate Zone Effect
Table 2 implicitly assumes Zone II fine aggregate. Zone I (coarser) reduces water demand slightly; Zone IV (finer) increases water demand by 6–18 L/m³. IS 10262 does not explicitly tabulate these adjustments — they emerge through the trial mix process. For Zone IV sand, IS 456 Cl. 5.3.2 requires engineer approval for use in structural concrete M30+.
T3
IS 10262:2019 Table 3 — Volume Fraction of Coarse Aggregate (jc)
jc = volume of dry-rodded coarse aggregate per unit volume of concrete · Crushed aggregate baseline
| MSA |
Zone I |
Zone II ★ |
Zone III |
Zone IV |
Rounded: add +0.02 |
| 10 mm |
0.52 | 0.50 | 0.48 | 0.46 | Add 0.02 to all values for rounded (river gravel) aggregate. Rounded particles pack less efficiently with angular CA, justifying higher CA volume fraction. |
| 20 mm ★ |
0.66 | 0.64 ★ | 0.62 | 0.60 |
| 40 mm |
0.74 | 0.72 | 0.70 | 0.68 |
Understanding jc
The jc value represents the volume of coarse aggregate (per unit volume of concrete) when the aggregate is in its dry-rodded state. It is dimensionless — m³ of CA per m³ of concrete. The CA mass is then calculated as:
CA (kg/m³) = jc × DRBD
where DRBD = Dry-Rodded Bulk Density of CA (kg/m³)
Measured per IS 2386 Part III — Compacted bulk density
Typical DRBD values:
20mm crushed granite: 1400–1550 kg/m³
20mm river gravel: 1480–1600 kg/m³
40mm crushed basalt: 1350–1500 kg/m³
Rationale for jc Variation
jc increases with MSA because larger aggregates have a lower surface-area-to-volume ratio and pack more efficiently, requiring less paste to coat and lubricate particle surfaces. jc decreases from Zone I to Zone IV because finer sand zones contain more fines that occupy interstitial voids — a larger fraction of the 1 m³ is taken by fine aggregate paste, leaving less room for coarse aggregate. Rounded aggregate gets +0.02 because spherical particles pack slightly better with angular coarse aggregate.
⚠️ DRBD is Not Standard Density: The Dry-Rodded Bulk Density (DRBD) must be measured in the laboratory per IS 2386 Part III using a standardised tamping rod procedure. Using the aggregate particle density (SG × 1000) instead of DRBD will dramatically over-estimate CA content — typically by 30–40%. Incorrect DRBD is one of the most common sources of large errors in Indian mix design practice.
9
Clause 9 — Trial Mix
IS 10262:2019 Cl. 9 — Mandatory trial programme before any design mix is released for production
IS 10262:2019 Cl. 9.1 — Purpose
The trial mix verifies that the calculated mix proportions produce concrete satisfying the specified requirements for workability and strength. No design mix is complete without a trial — even experienced designers using identical materials cannot bypass this stage because cement chemistry varies between batches, aggregate surface texture varies between quarry faces, and temperature conditions affect actual water demand.
IS 10262:2019 Cl. 9.2 — Trial Programme
Minimum three trial batches are required: Trial 1 at the design w/c ratio (primary); Trial 2 at w/c × 0.90 (−10%, higher strength reference); Trial 3 at w/c × 1.10 (+10%, workability reference). Minimum volume per batch: 0.030 m³ (30 litres). Cast minimum 3 × 150 mm cubes per trial. Record fresh concrete properties (slump, temperature, density, air) at each trial.
IS 10262:2019 Cl. 9.3 — Acceptance Criteria
The 28-day mean cube strength of the trial batch must equal or exceed the Target Mean Strength (TMS = fcr). Additionally, slump must be within ±25 mm of the design target. If 28-day mean strength is less than 90% of TMS, the mix must be redesigned with a lower w/c or higher cement. If strength exceeds TMS by more than 20%, the designer may consider increasing w/c (reducing cement content) to improve economy, subject to IS 456 limits.
TRIAL MIX QUANTITIES (scaled from per-m³ design):
Batch volume = 30 L = 0.030 m³
For each material:
Trial quantity (kg or L) = Design quantity per m³ × 0.030
Example (M30 design: C=331, W=149, FA=950, CA=928):
Trial cement = 331 × 0.030 = 9.93 kg
Trial water = 149 × 0.030 = 4.47 L
Trial FA = 950 × 0.030 = 28.50 kg
Trial CA = 928 × 0.030 = 27.84 kg
Cast 3 cubes → demould at 24h → cure in water at 27°C → test at 28d
A
Annex A — Moisture Correction
IS 10262:2019 Annex A — Daily adjustment of batch quantities for field aggregate moisture
The design mix is on an SSD (Saturated Surface Dry) basis — aggregates contain all the water they can absorb but no surface water. Field aggregates rarely match this condition. Annex A provides the daily correction method.
FOUR MOISTURE STATES (IS 2386 Part III):
1. Oven Dry (OD): All moisture removed; absorption = 0
2. Air Dry (AD): Surface dry but partially absorbed; below SSD
3. SSD: Fully saturated, no surface moisture (design basis)
4. Wet/Field: Saturated + surface moisture (typical site condition)
ANNEX A CORRECTION FORMULAS:
Free moisture of FA = Total moisture% − Absorption%
Free moisture of CA = Total moisture% − Absorption%
Water from FA_surface = FA_SSD × (free moisture% / 100)
Water from CA_surface = CA_SSD × (free moisture% / 100)
Batch water = W_design − Water_from_FA − Water_from_CA
FA batch mass = FA_SSD × (1 + FA_total/100) / (1 + FA_abs/100)
CA batch mass = CA_SSD × (1 + CA_total/100) / (1 + CA_abs/100)
Verification: Batch water + Water_from_FA + Water_from_CA = W_design ✓
Measurement Frequency: IS 10262 Annex A corrections must be applied for every production shift. Moisture content should be measured: (a) after each aggregate delivery; (b) at the start of each pour; (c) whenever visual inspection suggests moisture change (rainfall, evaporation, sprinkling). The most reliable methods are the speedy moisture meter (site) and the oven-dry method (IS 2386 Pt III, lab reference). Microwave methods are fast and widely used in RMC plants.
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Key Changes in IS 10262:2019 vs IS 10262:2009
Major differences between the Fifth (2019) and Fourth (2009) revisions
2019 ADDITION
Cl. 5.7 — SCM k-factor Method (Formalised)
The 2009 edition had limited guidance on SCM additions. The 2019 revision formally codifies the k-factor efficiency method: fly ash k=0.25, GGBS k=0.60, silica fume k=2.50. The effective w/c formula — W/(C + k×f) — is now the mandatory approach for IS 456 Table 5 durability compliance when SCMs are used. This reflects the widespread adoption of blended cements and separately batched SCMs in Indian construction.
2019 REVISION
Table 1 — Standard Deviation Values
The 2009 edition used σ = 4.0 MPa for M10–M35 and 5.0 MPa for M40+. The 2019 revision restructures this: 3.5 MPa for M10–M15, 4.0 MPa for M20–M25, and 5.0 MPa for M30–M55. This change increases the design margin (TMS) for M30 from fck+6.6 to fck+8.25 MPa — a significant increase that raises design cement contents and better reflects Indian production variability.
2019 REVISION
Table 2 — Extended to 150mm Slump
The 2009 Table 2 only covered slump up to 100 mm. The 2019 revision adds columns for 125 mm and 150 mm slump — recognising that pumped concrete, congested reinforcement and modern SP-assisted mixes routinely target 100–150 mm slump. This extension makes the standard directly applicable to RMC production without extrapolation.
2019 ADDITION
Annex C — High-Performance Concrete Guidance
The 2019 revision adds Annex C with guidance notes for M60+ and HPC. The annex acknowledges that IS 10262 Figure 1 does not extend reliably above M55, and that HSC design requires: actual production σ (not Table 1), verified aggregate quality (crushing value, LA abrasion), silica fume or GGBS additions, and high-WR PCE SP. Trial mix programmes for HPC are more extensive — minimum 5 batches recommended.
2019 REVISION
Workability Guidance Updated (Cl. 4.4)
The 2019 edition provides more detailed workability guidance including explicit reference to flow table and VeBe time as alternatives to slump — acknowledging that slump alone is inadequate for very stiff (VeBe) and very fluid (SCC) mixes. The revision also notes that target slump should be specified at the point of placement (not batching), requiring the designer to account for transit time and slump loss.
2019 REVISION
Trial Mix Requirements Strengthened (Cl. 9)
The 2019 revision makes the three-trial programme more explicit and adds guidance on the rejection criterion — 28d mean < 0.9 × TMS triggers mandatory redesign. The 2009 edition was less explicit on the failure threshold. The 2019 edition also adds fresh concrete testing requirements (density, temperature, air content) alongside the slump check at each trial.
456
IS 10262:2019 + IS 456:2000 — Interaction
How the two standards work together — IS 10262 provides the design method; IS 456 provides the compliance limits
IS 10262 and IS 456 are complementary, not alternative, standards. IS 10262 is a methods standard (how to design) while IS 456 is a compliance standard (what the design must satisfy). A mix design must satisfy both simultaneously.
| IS 10262 Action | IS 456 Constraint Applied | Effect on Design |
|---|
| Select grade (Step 1) | IS 456 Table 5: min grade per exposure | Grade cannot be below Table 5 minimum for exposure class |
| Select w/c (Step 2) | IS 456 Table 5: max w/c per exposure | Strength-derived w/c may not exceed IS 456 maximum |
| Calculate cement (Step 4) | IS 456 Table 5: min cement per exposure | Calculated C must meet or exceed IS 456 minimum |
| Calculate cement (Step 4) | IS 456 Cl. 8.2.4.2: max 450 kg/m³ | SP mandatory if C would exceed 450 |
| Check MSA (Pre-design) | IS 456 Cl. 26.4.2: MSA limits | MSA constrained by section, cover and bar spacing |
| Specify cover (Pre-design) | IS 456 Table 16: min cover by exposure | Cover must equal or exceed Table 16 values |
| Production monitoring | IS 456 Cl. 15: acceptance criteria | Ongoing sampling frequency and acceptance limits govern production |
| Design mix obligation | IS 456 Cl. 9.1: M25+ requires IS 10262 | Nominal mix not permitted for M25 and above |
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International Method Comparison
IS 10262:2019 vs ACI 211.1, DOE Method, EN 206 — approaches to the same design problem
IS 10262:2019
India · BIS
Prescriptive step-by-step. Figure 1 (strength-w/c curves) + Table 2 (water) + Table 3 (CA fraction jc). Absolute volume method. Strong IS 456 durability integration. 28-day cube strength. Widely used in India, Bangladesh, Sri Lanka, Nepal.
ACI 211.1
USA · ACI
Volume-based absolute method. Free w/c selection from strength tables. Water content by MSA and slump. CA fraction by oven-dry bulk density. Cylinder strength (f'c, not cube). Extensive fine aggregate proportion adjustment by FM. More grade-exposure separation than IS.
DOE Method (UK)
UK · BRE/ICE
Graph-based UK method (also called Road Note 4 for pavements). Separate curves for free-w/c vs compressive strength by cement type. Water content by aggregate type and slump. C:A ratio approach for proportioning. Similar to IS 10262 in spirit; different curves calibrated for UK cements and aggregates.
EN 206 / prEN
Europe · CEN
Performance-based. Specifies concrete classes (C8/10 to C100/115) and exposure classes (XC, XS, XF, XA, XD). Does not prescribe mix design method — leaves method to national standards. Strong durability framework. Cylinder strength (f'c) as primary measure. EN 206 requires national annexes; mix design typically follows national guidance (BS EN, DIN, NF).
| Feature | IS 10262:2019 | ACI 211.1 | DOE | EN 206 |
|---|
| Strength measure | Cube (150mm, 28d) | Cylinder (6"×12", 28d) | Cube (150mm, 28d) | Cylinder (EN 12390) |
| w/c curve method | Figure 1 (4 cement curves) | Tabulated strength classes | Graphical (cement type) | National standard |
| Water content | Table 2 (MSA × slump) | Table 6.3.3 (MSA × slump) | Figure 4 (type × slump) | Not prescribed |
| CA proportioning | Table 3 (jc × DRBD) | Oven-dry bulk density | C:A ratio curves | Not prescribed |
| Durability integration | IS 456 Table 5 | ACI 318/201 exposure limits | BS 8500 / EN 206 | EN 206 exposure classes |
| SCM treatment | k-factor (0.25/0.60/2.50) | Cementitious factor | Cement equivalent | k-factor (national annex) |
| Trial mixes | Mandatory (Cl. 9) | Recommended | Recommended | Required (EN 206 Cl. 5.3) |
| Worked example | Annex B | Appendix examples | Full worked example | National examples |
ACI 211.1 vs IS 10262 — Key Practical Difference: ACI 211.1 uses oven-dry bulk density for CA proportioning, while IS 10262 uses dry-rodded bulk density (DRBD). Both are measured in standardised compacted states but the ACI oven-dry value is slightly higher than IS 10262 DRBD in most cases. Additionally, ACI 211.1 applies a fineness modulus (FM) correction to fine aggregate content — IS 10262 does not explicitly use FM for proportioning, though FM informs the zone classification (IS 383). For the same materials, the two methods typically produce cement contents within 5–15 kg/m³ of each other.
