Portland slag cement is prepared by combining gypsum, cement clinker and granulated blast furnace slag(GGBS) in proper proportions. The production of Portland slag cement is developed mainly for the consumption of blast furnace slag in a usable manner.
Although blast furnace slag cement has many advantages over ordinary portland cement. The physical properties are similar to OPC. But it has a low heat of hydration and it gives better resistance to chlorides, soils, sulfates and alkalies.
You know that slag is byproduct formed in blast furnace slag during smelting or refining of ore. This byproduct can be effectively used for the production of slag cement. About 25 to 70 percent of waste slag can be added for production which makes the manufacturing of cement more economical.
Portland blast furnace cement is similar to OPC in terms of soundness, fineness and strength. But the rate of hardening comparatively low. This means, the earlier strength is comparatively lower, but the final strength will always similar to the normal cement.
Since the heat of hydration is very low, this cement can be widely used for mass concrete structures such as dams, bridge piers etc.
The below figure shows the representation of blast furnace slag. You can see the functioning of blast furnace slag here.
What are the advantages of blast furnace slag cement?
- More resistance to chemical attack.
- Refinement of Pore structure
- Less heat of hydration
- More workability
- Fewer shrinkage cracks
- More resistance to alkali-silica reaction.
- Fewer chances for cracks.
- More economical
- Easier placement and more finishes.
- Ease of pumping of concrete.
Where can Portland slag cement(PSC) be used?
- Mass concrete structures
- Water retaining structures
- More usable for marine and coastal constructions.
- Precast products.
- Foundation or PIle constructions.
- All residential building structures.