What is Portland Slag Cement (PSC)?
Portland Slag Cement is made by inter-grinding Portland clinker with ground granulated blast-furnace slag (GGBS) — a by-product of steel making — and gypsum. It is manufactured to IS 455, which allows slag content from 25% to 70% of the cement.
Slag reacts slowly with the lime released by clinker hydration, creating a dense, low-permeability concrete that resists sulphate and chloride attack far better than plain OPC. That makes PSC one of the most durable cements for Gujarat's long coastline and saline soils.
Where PSC performs best
- Ports, jetties, breakwaters and coastal structures — Mundra, Kandla, Pipavav, Hazira, Dahej
- Foundations and piles in sulphate- or chloride-rich soil and groundwater — Kutch, the Saurashtra coast and south Gujarat
- Canal lining, water-retaining structures and water treatment plants
- Sewage, effluent treatment and industrial structures with chemical exposure
- Mass concrete and thick rafts where low heat of hydration limits cracking
PSC vs PPC vs OPC
| Property | PSC (IS 455) | PPC (IS 1489-1) | OPC 53 (IS 269) |
|---|---|---|---|
| Blending material | GGBS (slag) | Fly ash | None |
| Early strength | Moderate | Moderate | High |
| Long-term strength | High | High | High |
| Heat of hydration | Low | Low | High |
| Sulphate / chloride resistance | Very good | Good | Lower |
| Best for | Marine, coastal, sulphate exposure | Plaster, masonry, mass concrete | High-rise, precast, fast pours |
Working with PSC on site
- Cure longer: at least 10 days, and 14 days or more in hot, dry or windy weather — slag concrete needs moisture to develop strength.
- Plan formwork: early strength is lower than OPC, especially in cool weather.
- Colour is normal: fresh slag concrete may show a temporary blue-green tint that fades on exposure to air.
- Follow the specification: for severe exposure your designer may call for PSC, SRC (IS 12330) or a specific GGBS content.
PSC brands and availability
PSC is produced by several manufacturers, including Nuvoco and Saurashtra Cement (the Hathi and Sidhee brands). Availability varies with each plant's allocation for your region, so we confirm brand options with your quotation. For special exposure classes we can also source sulphate-resisting cement (SRC).
Get PSC or SRC with test certificates for every load.