Autoclaved Aerated Concrete (AAC / BCA)
Romanian Technical Denomination: Beton Celular Autoclavizat (BCA)
Precast lightweight cellular masonry material produced by autoclaving a mix of quartz sand, cement, lime, water, and aluminum foaming agent.
LEVEL 1: QUICK UNDERSTANDING (EXECUTIVE SUMMARY)
INVESTORS & DEVELOPERSPrecast lightweight cellular masonry material produced by autoclaving a mix of quartz sand, cement, lime, water, and aluminum foaming agent.
Infill perimeter walls in reinforced concrete multi-story frames, Interior dividing and compartmentation walls
01. TECHNICAL OVERVIEW & ENGINEERING CHARACTERISTICS
Autoclaved Aerated Concrete (AAC / BCA in Romania) compliant with SR EN 771-4:2015. Contains millions of closed microscopic air pores (up to 80% porosity by volume), delivering superior thermal insulation (λ = 0.09 - 0.12 W/mK) at very low bulk densities (400-500 kg/m³). Widely used for non-load-bearing infill walls in high-rise RC frames.
02. CONSTITUENTS & MANUFACTURING SPECIFICATION
- ▸Finely ground quartz sand (SiO2), Portland cement (CEM I), quicklime (CaO), gypsum, and water
- ▸Aluminum powder foaming agent creating cellular hydrogen pore network
- ▸High-pressure steam autoclaving at 190°C and 12 bar pressure for 10-12 hours
✓ ADVANTAGES & STRENGTHS
- •Lightweight material (400-500 kg/m³), reducing seismic dead weight on structural columns and foundations
- •Superior thermal insulation compared to heavy ceramic blocks (reduces thermal bridging)
- •Precise dimensional tolerances (±1.5mm) enabling thin-bed adhesive mortar application (1-2mm joints)
- •Effortless workability (can be cut, grooved, and shaped with standard hand or band saws)
⚠ LIMITATIONS & RISK FACTORS
- •Lower compressive strength (2.5-5.0 MPa) restricting use to infill or low-rise confined masonry
- •Higher hygroscopic water absorption if exposed directly to driving rain without rendering
- •Lower acoustic mass attenuation compared to solid masonry of equivalent thickness