Sand-lime bricks are made out of sand, lime and water (no additives). By high pressing the mixture and autoclaving afterwards a firm white building material is produced. Good acoustic insulation, good heat & humidity accumulation as well as excellent fire resistance are the main parameters for architects to prescribe lime sand bricks for each building project.
Problems
High-strength bricks are often needed for heavy load-bearing masonry. External masonry and internal walls typically need thermal and sound insulation, as designers aim to achieve multiple benefits for the entire building by using the same type of wall building materials. Masonry needs to be cost-efficient, not only in terms of the bottom line but also as building material.
Solutions
Sand-lime brick is a precast building material that simultaneously provides structure, thermal insulation and sound insulation. SLB is produced by mixing lime, sand, and water into a batch process, where the lime must react in due time with the quick lime to develop some early green strength before entering the autoclave. Quick lime – which has a specific chemistry, reactivity and fineness – is one of the key elements in the process to cast sand-lime products. Lime plasters and renders have a similar linear expansion coefficient as sand-lime bricks, thus avoiding cracking at the surface.