Which Additives Improve the Performance and Durability of Fired Bricks?
To meet the diversified market demand for high-strength, durable, lightweight and frost-resistant fired bricks, targeted functional additives are widely used in modern brick production to comprehensively enhance the physical properties and service life of finished products. Scientific additive selection and proportioning are key to manufacturing high-performance fired bricks and improving product market competitiveness.
Strengthening agents are core additives for improving brick strength. They can significantly enhance the dry strength of green bricks and the compressive strength of finished fired bricks, effectively solving the problems of easy damage in brick demolding, transportation and construction, and improving the structural stability of brick masonry.
Pore-forming and aerating additives are exclusive materials for manufacturing lightweight thermal insulation fired bricks. During high-temperature firing, these additives produce a large number of uniform micron-scale pores inside the brick body through self-combustion or high-temperature decomposition and gas release. Uniform fine pores can effectively reduce brick bulk density, reduce thermal conductivity, and significantly improve the thermal insulation and heat preservation performance of the product. Common efficient pore-forming materials include polystyrene particles, sawdust, fly ash, tailings, lignite, coke powder, slag and diatomaceous earth, which are the mainstream choices for industrial mass production of lightweight bricks.
Frost resistance additives are essential for bricks used in cold-region construction. Professional additives such as refractory clay, montmorillonite, illite clay, sand, broken brick powder, expanded clay ceramsite powder and polystyrene can optimize the internal structure of bricks, improve compactness and freeze-thaw cycle resistance, prevent brick peeling, cracking and pulverization caused by low-temperature frost heave, and ensure the long-term service stability of building walls in cold climates.
Freeze-protection additives prevent green brick freezing damage in low-temperature production environments. Salt is a traditional and cost-effective freeze-protection material that lowers the freezing point of moisture in green bricks. However, salt addition greatly increases the risk of brick efflorescence. Therefore, it must be used with matched anti-efflorescence agents in formal production to avoid secondary quality issues.
