1. What is aerated cement or cellular lightweight concrete (CLC)?
Aerated cement is a lightweight concrete that includes air bubbles (or foam) in the mix. It reduces density while maintaining sufficient strength, thermal insulation, and fire resistance. It's commonly used for blocks, panels, and lightweight fills.

2. What are the main ingredients in aerated cement?
Cement (OPC or blended), foaming agent (protein-based or synthetic), water, and optionally fly ash, sand, or other fillers.

3. How is the foam created and added?
A foaming agent is mixed with water and agitated in a foam generator. This foam is then mixed into the cement slurry to trap air within the mix.

4. What are the typical densities used?
300-600 kg/m³: Insulation or non-load-bearing fill
600-1200 kg/m³: Blocks or partition walls
1200-1800 kg/m³: Structural applications (with reinforcement)

5. How long does it take for aerated cement to set and cure?
Initial set: ~2-4 hours (can be sped up with CSA cement)
Final cure: 7-28 days for full strength
Steam curing or warm curing rooms can reduce curing time.

6. Is aerated concrete strong enough for structural use?
For load-bearing structures, higher densities (1200 kg/m³ and above) with reinforcement can be used. However, for most structural elements, it's paired with steel or used as infill.

7. What are the benefits of using aerated cement?
Lightweight, thermal insulation, fire resistance, lower dead load, easy to cut and shape, reduces cost of foundations.

8. What are the limitations?
Lower compressive strength than traditional concrete, requires careful foam control, may be sensitive to water if not sealed, requires curing time and protection from drying too fast.

9. What types of foaming agents are used?
Protein-based: Natural, more stable foam, better for blocks
Synthetic-based: Cheaper, less stable over long times

10. Can I make aerated concrete on-site?
Yes, with a foam generator, mixer, and molds or cast-in-place forms. It's widely used in on-site small home and prefab construction.

11. Can I use fly ash in aerated concrete?
Yes, Class F fly ash is commonly used as a partial cement replacement to reduce cost, improve work-ability, and reduce shrinkage.

12. What's the difference between CLC and AAC (Autoclaved Aerated Concrete)?
CLC: Made without high-pressure curing, poured into molds
AAC: Requires autoclaving (steam under pressure), factory-controlled
AAC has better strength and dimensional stability but is more costly to produce

13. How do you prevent cracks in aerated cement?
Use proper water-cement ratio, avoid rapid drying (cover during cure), use fiber reinforcement or additives (like polypropylene fibers).

14. Can you reinforce aerated cement?
Yes, fiber reinforcement (glass, polymer, basalt) or mesh reinforcement is used for structural applications.

15. Is it environmentally friendly?
Yes-reduced cement content, use of industrial by-products (like fly ash), and lower energy for production contribute to its eco-friendly profile.