To adjust the formula for Autoclaved Aerated Concrete (AAC) block production, you need to carefully control the key raw materials and their proportions to achieve the desired block properties (such as strength, density, and thermal insulation). Here's an overview of the process:

1. Raw Material Adjustment:

• Cement: The amount of cement impacts the strength and durability of the AAC blocks. Adjusting the cement content can modify the compressive strength.

• Lime: Lime reacts with siliceous materials to form calcium silicate hydrates, which contribute to the block’s strength. Increasing lime can improve strength but may also impact the block's weight and thermal insulation.

• Silica (Sand): Silica is the primary component that reacts with lime to form the structure of the blocks. Adjusting silica content will affect the density and strength of the blocks.

• Aluminum Powder: The amount of aluminum powder used controls the expansion process (i.e., the formation of gas bubbles). A higher quantity of aluminum powder increases the porosity, leading to lighter blocks with better thermal insulation but lower compressive strength.

• Water: Water is used to hydrate the cement and lime. The water-to-cement ratio is critical in determining the final consistency and strength of the blocks. Excess water can result in weak blocks, while too little water may hinder the reaction process.

2. Proportions for Adjustments:

• To make blocks lighter (lower density), increase the aluminum powder content and reduce the cement or sand content.

• To increase strength, reduce aluminum powder and adjust the cement and lime ratio accordingly.

• For better insulation properties, adjust the proportions of silica, lime, and aluminum powder.

• Generally, the formula can be adjusted by altering the proportions of the raw materials. For example:

3. Temperature and Curing Time Adjustment:

• The temperature and curing time of the autoclaving process (in a steam chamber) also play a significant role in the final properties of the AAC blocks. Longer autoclaving times and higher temperatures generally lead to better strength but may decrease the thermal insulation properties. Adjust these parameters based on the intended use of the blocks.

4. Testing and Optimization:

• It's crucial to regularly test samples during production to monitor the physical and mechanical properties of the blocks, such as compressive strength, density, and thermal conductivity. Based on these tests, you can fine-tune the formula to meet the specific requirements of the blocks.

By balancing the ingredients and adjusting the autoclaving process, you can fine-tune the characteristics of the AAC blocks to match project-specific needs.