All Frequently Asked Questions (FAQs) About AAC, AAC Plants, Blocks, and More

1. What is AAC?

AAC, short for Aerated Autoclaved Concrete, is an innovative, lightweight building material widely recognized as a sustainable alternative to traditional red clay bricks and conventional concrete blocks. Its composition is carefully formulated using natural and industrial byproducts, including sand (or fly ash, a recycled waste from coal-fired power plants), lime, gypsum, aluminum powder (as a foaming agent), and a specialized foaming agent.

The manufacturing process of AAC involves mixing these raw materials to create a slurry, which then undergoes a chemical reaction—aluminum powder reacts with lime to release hydrogen gas, forming tiny, uniform air bubbles throughout the mixture. This aeration gives AAC its signature lightweight properties. The mixture is then poured into molds, allowed to set (or “pre-cure”), and finally processed through high-temperature autoclaving (steam curing under pressure) to achieve its structural strength and durability.

Beyond replacing red clay bricks, AAC is valued for its thermal insulation, soundproofing, and fire-resistant qualities, making it ideal for residential, commercial, and industrial construction projects.

2. What is the Production Capacity and Available Models of AAC Machinery?

AAC machinery models are specifically designed to cater to different production scales, ranging from small-scale operations to large industrial plants. The daily production capacity of these machines spans 150 cubic meters (m³) to 800 cubic meters (m³), allowing businesses to choose a model that aligns with their market demand, budget, and long-term expansion plans.

Each model is engineered with varying levels of automation, curing systems, and waste management features to optimize efficiency. For instance, low-capacity models (e.g., 150 m³/day) are often cost-effective and suitable for startups or local construction markets, while high-capacity models (e.g., 800 m³/day) integrate fully automated systems to handle large-volume production with minimal manual labor.

For detailed technical specifications, including power consumption, labor requirements, and output efficiency of each model, please click here for more details（https://www.ruichi-equipment.com).

3. What is an AAC Block?

An AAC Block is a precast, lightweight building component made from Aerated Autoclaved Concrete, designed as a direct replacement for traditional red clay bricks. Its key characteristics include:

Lightweight Nature: AAC blocks have a density ranging from 550 kg/m³ to 750 kg/m³—significantly lower than red clay bricks (which typically have a density of 1800–2000 kg/m³) and conventional concrete blocks. This light weight reduces the overall load on building foundations, lowering construction costs for structural support and enabling faster installation (as fewer workers are needed to handle the blocks).

Structural and Functional Benefits: Despite being lightweight, AAC blocks offer excellent compressive strength (depending on curing method), thermal insulation (reducing energy costs for heating and cooling), and sound absorption (enhancing indoor comfort). They are also fire-resistant (able to withstand high temperatures for extended periods) and resistant to mold and mildew, thanks to their non-porous, autoclaved structure.

AAC blocks are available in various standard sizes to fit different construction needs, from load-bearing walls to non-load-bearing partitions. For more information on their performance in different applications, please click here for more details.

4. What Are the Types of Curing for AAC Blocks?

Curing is a critical step in AAC block production, as it determines the material’s strength, durability, and consistency.

Standard Autoclaving (High-Pressure Curing)

This is the industrial-grade curing method used for high-quality AAC blocks. The process involves placing pre-cured AAC mixtures into a sealed autoclave (a large, pressure-resistant chamber) and exposing them to:

Temperature: 180–200°C

Pressure: 12–13 kg/cm²

Duration: 8 hours

The high temperature and pressure accelerate the chemical reaction between the raw materials (e.g., lime and silica), resulting in a dense, strong structure with consistent compressive strength (4–5.5 N/mm²). This method is ideal for large-scale production and blocks used in load-bearing walls or structural applications.

5. What Equipment is Necessary for Steam Curing?

For Standard Autoclaving (High-Pressure Curing):

Boiler: Generates high-pressure steam required for the autoclave. The boiler’s capacity must match the autoclave’s size to maintain consistent temperature and pressure.

Autoclave: A large, sealed, pressure-resistant chamber where the AAC mixtures are cured. Autoclaves are typically made of stainless steel or high-grade carbon steel to withstand extreme conditions.

6. What Are the Standard Sizes of AAC Blocks, and How Many Fit in 1 Cubic Meter?

AAC blocks are available in standardized dimensions to simplify construction planning. Below are common sizes (Length × Height × Thickness) and the number of blocks per cubic meter (m³), along with approximate weights (based on a density of 600 kg/m³):

Standard Size (L × H × T, mm) Number of Blocks per 1 m³ Approximate Weight per Block (kg)

Standard Size (L × H × T, mm)	Number of Blocks per 1 m³	Approximate Weight per Block (kg)
500 × 200 × 100	100	~6.0
500 × 200 × 150	67	~9.0
500 × 200 × 200	50	~12.0

Note: The number of blocks per m³ is calculated by dividing 1 m³ (1,000,000 cm³) by the volume of one block (converted to cm³). For example, a 500×200×100 mm block has a volume of 50×20×10 = 10,000 cm³, so 1,000,000 ÷ 10,000 = 100 blocks per m³.

7. What Are the Applications of AAC?

AAC is a versatile material with a wide range of construction applications, thanks to its lightweight, insulating, and strong properties. Its primary uses include:

Structural Blocks: Used as load-bearing or non-load-bearing walls in residential, commercial, and industrial buildings. AAC blocks reduce construction time and foundation costs compared to red clay bricks.

Panels: Precast AAC panels (e.g., wall panels, floor panels, and roof panels) are used for quick assembly in modular construction. These panels are lightweight yet strong, making them ideal for high-rise buildings.

Partition Walls: Thin AAC blocks or panels are used to create internal partitions, as they offer soundproofing and thermal insulation without adding excessive weight to the structure.

Fire-Safe Components: AAC’s fire-resistant properties make it suitable for fire-rated walls, chimneys, and industrial structures where fire safety is critical.

Sound Barriers: AAC’s sound absorption