IS 9103:1999 is the Indian Standard (BIS) for admixtures for concrete - specification. This standard specifies the requirements for seven types of chemical admixtures for concrete, such as plasticizers, superplasticizers, and retarders. It covers material classification, physical and chemical performance criteria, testing procedures, and marking instructions to ensure the quality and uniformity of admixtures used in construction.
Specifies requirements for chemical admixtures to be used in concrete to modify its properties.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
IS 9103 specifies the acceptance criteria for chemical admixtures used in cement, mortar, and concrete — water-reducers (plasticizers), superplasticizers (HRWR), retarders, accelerators, and air-entraining agents. If your mix design (IS 10262:2019) targets w/c < 0.45 or workability of slump > 100 mm, you're using an admixture and IS 9103 is the BIS gate.
You specify IS 9103 in the BOQ when: - Pumping concrete on multi-storey or long-distance pumping (PCE-based superplasticizer) - Hot-weather concreting where set-retardation is needed (sulphonated naphthalene with retarder) - Cold-weather concreting where accelerated set is needed (calcium chloride or non-chloride accelerator) - Marine / freeze-thaw exposure where air-entrainment is required (3-6 % air content per IS 456 Clause 8.2) - Self-compacting concrete or high-strength mixes (>M50)
IS 9103 doesn't specify *dosage* — that's set by trial mix per IS 10262. It specifies what the admixture itself must deliver against a control mix in standardised lab conditions.
Performance is measured against a reference mix made with the same cement, aggregate, and w/c, with vs without admixture.
Water reduction (Type A — water reducer, Type F — high-range water reducer): - Type A: ≥ 5 % water reduction at equal slump - Type F (superplasticizer): ≥ 12 % water reduction - Type G (HRWR + retarder): ≥ 12 % water reduction + retardation
Setting time deviation (vs control, by Vicat): - Type A water reducer: −60 to +90 minutes - Type B retarder: +90 to +210 minutes (delayed) - Type C accelerator: −60 to −210 minutes (faster) - Type D water reducer + retarder: as Type A water reduction + Type B retardation - Type E water reducer + accelerator: as Type A water reduction + Type C acceleration
Compressive strength of treated concrete vs control: - Type A, B, D, E, F, G: not less than control at 1, 3, 7, 28 days; ≥ 110 % at 28 days for Type F and G - Type C accelerator: ≥ 125 % at 24 h, ≥ 100 % at 28 d
Chloride content: ≤ 0.2 % by mass of admixture (so total Cl⁻ in concrete stays below the IS 456 Clause 8.2.5.2 limits — 0.6 kg/m³ RCC, 0.4 kg/m³ PSC).
Air content (entraining admixture): 3-6 % at the fresh stage; loss after 1 hour ≤ 1 %.
Bleeding: treated concrete ≤ 100 % of control.
1. No project-specific trial mix. IS 9103 acceptance is in the *manufacturer's* lab against a *reference* cement and aggregate. Your project's cement and aggregate are different. Always run trial mixes per IS 10262 Clause 6 before fixing the dosage. 2. Overdosing for slump retention without retarder. Standard SP at high dose causes early stiffening or false set. If pumping > 30 minutes from batching, specify Type G (SP + retarder) instead of Type F. 3. Mixing two admixtures on site. Different chemistries (SNF and PCE, SNF and lignosulphonate) can cross-react and produce gross slump loss or set anomalies. Use one supplier's compatible system. 4. Ignoring chloride contribution. A 1 % superplasticizer at the upper IS 9103 chloride limit (0.2 %) adds 0.002 kg Cl⁻ per kg admixture. At 1 % SP dose on 350 kg cement = 3.5 kg admixture/m³ × 0.002 = 0.007 kg/m³ Cl⁻. Negligible alone but adds up if water and aggregates also bring chlorides — tally per IS 456 Clause 8.2.5.2. 5. Calcium chloride accelerator in RCC — banned by IS 456 Clause 8.2.5.2 for prestressed concrete and for RCC where steel is present. Use non-chloride accelerators (calcium nitrate, calcium nitrite, calcium formate) instead. 6. Thinking 'admixture compatible with all cements'. Test against the specific cement source. Even within OPC 43, fineness and C₃A vary enough to shift required SP dose by 30 %.
Source qualification (one-time per supplier-product pair): - Full IS 9103 panel by an accredited (NABL) lab - Manufacturer's certificate covering all the parameters above - Datasheet stating admixture type (A through G), recommended dosage range, and shelf life
Project trial mix (before procurement): - 3 dosages bracketing the supplier's recommendation (e.g., 0.6 %, 0.8 %, 1.0 % by mass of cement) - Measure slump, slump retention at 30 min and 60 min, 1d/3d/7d/28d strength, bleed test - Document one final dose for site use
Routine acceptance at site: - Manufacturer's batch certificate per drum/IBC delivery - Visual inspection: separation, sediment, gel formation = reject - Specific gravity check (must match the supplier's declared value within ±2 %) — quick spot check via hydrometer - Concrete cube tests already part of IS 456 Clause 16 acceptance — these implicitly verify the admixture is performing
Storage: cool dry shed, off the floor, FIFO. Most SPs have 6-12 month shelf life; don't use anything visibly separated, frozen-thawed, or beyond expiry.
Workflow sequence: 1. Mix-design target (IS 10262:2019 Clause 4) — characteristic strength, exposure, max w/c. 2. Decide if admixture is needed — if w/c < 0.50 OR slump > 75 mm, almost always yes. 3. Select admixture type — pumping = SP (Type F or G); hot weather + pumping = Type G; pre-cast cycle time = Type C accelerator; marine = air-entraining. 4. Specify in BOQ as 'IS 9103 Type X' plus brand/equivalent. 5. Trial mix with the specific cement + aggregate + water source. Lock dose at the trial. 6. Procurement gate: source qualification dossier (IS 9103 NABL test reports + datasheet). 7. Site QA/QC: per-delivery batch certificate, specific-gravity check, plus the standard fresh and hardened concrete tests.
The admixture is an enabler, not a band-aid. If the mix is failing, the answer is rarely 'add more admixture' — it's usually a w/c or aggregate gradation problem from upstream.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Water Reduction (Superplasticizer/HRWR) | ≥ 20% | ≥ 12% | ASTM C494 (Type F) |
| Chloride Content (for Prestressed Concrete) | ≤ 0.2% by mass of admixture | Typically must be 'chloride free', defined as ≤ 0.1% by mass | EN 934-2 |
| 3-Day Compressive Strength (Superplasticizer/Type F) | ≥ 140% of reference | ≥ 140% of control | ASTM C494 (Type F) |
| 28-Day Compressive Strength (Superplasticizer/Type F) | ≥ 115% of reference | ≥ 115% of control | ASTM C494 (Type F) |
| Initial Setting Time (Retarder/Type B) | Between 1 hr and 3.5 hrs later than reference | Between 1 hr and 3.5 hrs later than control | ASTM C494 (Type B) |
| Final Setting Time (Retarder/Type B) | Shall not be retarded more than 3.5 hrs compared to reference | Shall not be retarded more than 3.5 hrs compared to control | ASTM C494 (Type B) |
| General Max Chloride Content (Non-Prestressed) | ≤ 2.0% by mass | ≤ 1.0% by mass (if not declared 'chloride-free') | EN 934-2 |