PSC in Practice — Durable, Low-Heat, Curing-Dependent
Like all slag-rich binders, every PSC characteristic flows from the slow slag reaction: low heat of hydration (excellent for thick/mass and hot-weather pours), refined low-permeability pore structure, strong sulphate/chloride resistance — but slower early strength and an acute dependence on curing and placing temperature. Under-cured PSC forfeits exactly the durability it was chosen for.
Key Requirements
•Design/accept at the specified (later) age — not an OPC 7-day clock
•Extended, careful moist curing — PSC is more curing- and temperature-sensitive than OPC
•Allow longer formwork stripping/loading times; control placing in hot/dry conditions
•Exploit the low heat for thick/mass and hot-weather pours; use fresh cement (slag binders are storage-sensitive)
•Don't over-cement to force early strength (negates the low-heat/durability/economy purpose)
Practical Notes
✓PSC is among the most durable/chemically-resistant general binders — but it is unforgiving: short curing or hot placing forfeits the durability advantage.
✓Excellent low-heat choice for mass concrete (with IS 457 controls) — but accept on late strength and cure hard.
Common Mistakes
⚠Stripping/loading on an OPC timeline.
⚠Short curing / hot placing (forfeits PSC durability).
⚠Over-cementing for early strength (defeats the low-heat/economy purpose).