If a concrete slab on ground is not exposed to sulfates, the cement used is most likely to be:

• A. Type 1
• B. Type 2
• C. Type 3
• D. Type 4

Answer: (A)

This question tests how sulfate exposure influences which cement type to use for a concrete slab. If the slab on the ground isn’t exposed to sulfates, there’s no need for sulfate-resistant cement. Ordinary Portland cement, Type I, is the standard, cost-effective choice that provides adequate strength for typical slabs. Other types add features you don’t need here: Type II offers some sulfate resistance but isn’t necessary without sulfate exposure; Type III provides early strength but increases heat and cost; Type IV is designed for very large masses to control heat of hydration; Type V is specifically for high sulfate exposure. So for a non-sulfate-exposed slab, Type I is the sensible, economical option.