Concrete engineered to outlive the chemistry of the sea.
Sulphate and chloride-resistant concrete for coastal, sewage, and aggressive environments. 100+ year design life. Verified RCPT. Dense, impermeable, defended.
Inside Alpha Marine
Alpha Marine is concrete engineered for the harshest service environments — saltwater exposure, sulphate-rich groundwater, sewage treatment infrastructure, marine and coastal structures, and chemical exposure conditions. Where conventional concrete fails in 15-25 years, Alpha Marine is designed for 100+ year service life.
The science is uncompromising. We use sulphate-resistant cement (SRC) per IS 12330 or specially blended OPC + GGBS (50%+) systems. W/C ratio capped at 0.40 maximum (often 0.35). High SCM replacement creates a denser, more impermeable matrix. RCPT results consistently below 2000 coulombs (classified "Very Low" per ASTM C1202). Water absorption below 2%.
These metrics matter because in marine environments, concrete fails through chloride ingress (corrodes rebar) and sulphate attack (expands and cracks the matrix). Alpha Marine's dense, low-permeability microstructure resists both. It costs more (premium 20-30%) but its lifecycle cost is dramatically lower — and structural failure in marine infrastructure is catastrophic.
Built for harsh environments
SRC per IS 12330 or OPC + 50%+ GGBS blend. C3A content controlled. Tested per IS 6909 sulphate exposure classes.
Tightly controlled water-cement ratio. Often 0.32-0.38 for severe exposure. Verified per batch.
High SCM replacement creates dense paste. Reduced porosity. Capillary network discontinuous.
Rapid Chloride Permeability Test per ASTM C1202. Classification: "Very Low" permeability.
Tested per IS 1199 / ASTM C642. Indicates extremely low porosity. Resistance to water ingress.
Service life modeling per fib Model Code. Designed for marine atmospheric, splash zone, and submerged exposure.
Built for these projects
Hotels and resorts within 1km of coastline. Coastal residential developments. Coastal infrastructure.
STPs, ETPs, sewage pipelines, manholes, treatment tanks. Continuous chemical exposure.
Bored cast in-situ piles in marine environments. Wharfs, jetties, bulkheads, sheet piles.
Chemical plants, fertilizer plants, paper mills, sulfate-rich groundwater zones, tanneries.
The fine print, in full
| Compressive Strength (28-day) | 30 – 50 N/mm² (per grade) |
| Cement Type | SRC (IS 12330) or OPC + GGBS 50%+ |
| Cement Content | 360 – 400 kg/m³ |
| Mineral Admixture | GGBS 50-60% or Fly Ash 30-40% |
| W/C Ratio | 0.32 – 0.40 (per exposure) |
| Coarse Aggregate | 20mm + 10mm crushed granite, low chloride |
| Aggregate Chloride Content | < 0.04% by mass |
| Aggregate Sulphate Content | < 0.4% by mass |
| Chemical Admixture | Calcium nitrite (corrosion inhibitor) for splash zone |
| RCPT (28-day) | < 2000 coulombs (Very Low per ASTM C1202) |
| Water Absorption | < 2% per IS 1199 |
| ISAT (10 min) | < 0.25 ml/m²/sec |
| Setting Time (initial) | 5 – 7 hours |
| Slump | 100 – 150 mm |
| Code Reference | IS 456:2000, IS 12330, IS 6909, IS 8112, IS 12089 |
Alpha Marine mix designs
Resources by role
- Use Alpha Marine for any structure within 1km of coast, STPs, water treatment, industrial chemical exposure, or sulphate-rich soils.
- Where service life >50 years is a design requirement.
- Lead time: Standard 24-hour notice. Custom mix design 7+ days for premium grades.
- Pricing: 20-30% premium over standard concrete. Lifecycle cost dramatically lower.
- BOQ: "M[X] RMC for [exposure class], IS 456:2000 Table 5 + IS 12330. Max W/C 0.40. Min cement 360 kg/m³. SCM ≥50%. RCPT ≤2000 coulombs. From Alpha Concrete or equivalent."
- Mix design code: AC-MR-[Grade]
- Documentation: SRC cement MTC, RCPT report, water absorption report, durability design statement.
- On receipt: Slump 100-150mm ±25mm. Verify temperature.
- Placement: Standard. Vibrate fully — don't rely on dense matrix to compensate for poor placement.
- Curing: CRITICAL. Minimum 21 days for marine grade. Wet curing throughout.
- Cover: Maintain rebar cover per IS 456 Table 16 for severe/extreme exposure (50-75mm).
About Alpha Marine
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The specifications shown represent typical ranges for Alpha Concrete's product family. Actual mix designs are project-specific and subject to verification by our QC team. Quoted specifications must be confirmed against actual lab results before commercial commitment. Contact our QC team for project-specific mix design certification.