MATERIALS

Sulphate Resistant Cement (SRC)

Cement for sulphate-rich soils per IS 12330

Also calledsrc cementsulphate resistant cementsrcsulfate resistant
Related on InfraLens
CODES
IS 12330
Definition

Sulphate Resistant Cement (SRC) is a special-purpose Portland cement designed to resist sulphate attack. Per IS 12330:1988, SRC has restricted C3A content (≤ 5% vs 8-12% in OPC) — the C3A reacts with sulphates to form expansive ettringite, causing concrete cracking and disintegration. Used in: (a) sulphate-rich groundwater conditions (industrial sites, agricultural areas with high SO4²⁻); (b) marine and brackish water exposure; (c) sewage and effluent treatment; (d) areas with sulphate-bearing soils.

Properties: (1) 28-day compressive strength: 33 MPa minimum (OPC 33 grade equivalent). (2) Fineness 280-330 m²/kg. (3) Setting time 30/600 minutes. (4) C3A content ≤ 5% (mandated). (5) Sulphate resistance verified by IS 4032 test. Cost: 15-25% premium over OPC. Indian manufacturers: Ultratech SRC, ACC SRC, Birla SRC, Dalmia SRC.

Applications in Indian construction: (1) Industrial structures with sulphate exposure (chemical plants, paper mills, pulp factories); (2) Marine and coastal structures (Bandra-Worli Sea Link, marine bridges, port infrastructure); (3) Sewage treatment plants and digester structures; (4) Agricultural sulphate-rich groundwater conditions (parts of Punjab, Haryana). The most-overlooked aspect of Indian SRC use: testing the actual exposure environment. Sulphate concentration in groundwater varies dramatically across India; explicit testing essential before specifying SRC vs OPC + barrier coating + protective measures.

Where used
  • Industrial structures with sulphate exposure (chemical, paper, pulp)
  • Marine and coastal structures (sea bridges, port)
  • Sewage treatment plants and digester structures
  • Agricultural sulphate-rich groundwater areas
  • Foundations in sulphate-bearing soils
Acceptance / threshold
Per IS 12330:1988: C3A content ≤ 5%; 28-day compressive strength 33 MPa minimum; setting time and soundness per IS 4032; mill test certificate verifying sulphate resistance.
Frequently asked
What is sulphate resistant cement?
Sulphate Resistant Cement (SRC) is special-purpose Portland cement with restricted C3A content (≤ 5%) designed to resist sulphate attack. Per IS 12330:1988. Used in sulphate-rich groundwater, marine/brackish water, sewage treatment plants, and sulphate-bearing soils.
Where is SRC cement used?
(1) Industrial structures with sulphate exposure (chemical plants, paper mills); (2) Marine and coastal structures (sea bridges, ports); (3) Sewage treatment plants and digesters; (4) Agricultural sulphate-rich groundwater; (5) Foundations in sulphate-bearing soils. Cost premium 15-25% over OPC; justified by service life extension (50+ vs 10-15 years for OPC in sulphate environments).
What is C3A in cement?
Tricalcium Aluminate (C3A or 3CaO·Al2O3) is one of the four main compounds in Portland cement (along with C3S, C2S, C4AF). C3A reacts with water to form ettringite — initially fine and helpful for setting, but can become expansive when exposed to external sulphate, causing cracking. Standard OPC: 8-12% C3A. SRC: ≤ 5% C3A — restricted to prevent sulphate attack.
Related materials terms
Ordinary Portland Cement (OPC)
33/43/53 grade Portland cement. 53 most common for structural use.
Portland Pozzolana Cement (PPC)
Cement blended with fly ash. More durable than OPC.
Portland Slag Cement (PSC)
Cement blended with blast furnace slag
Aggregates (Fine & Coarse)
Coarse (10-40mm) and fine (sand) aggregates per IS 383
Sand (River / M-Sand)
Fine aggregate. River sand or manufactured sand.
Brick / Block Masonry
Bricks per IS 1077, blocks per IS 2185
Tile (Floor / Wall / Roof)
Floor/wall/roof tiles per various IS codes
Paint & Coatings
Wall paint, primer, putty, coatings