Autoclaved brick from low-silicon tailings

Abstract

The load-bearing brick is made from low-silicon tailings by pressing and autoclaving process, in the presence of alkali-activated slag/fly ash cementing material (AAFSC). Tailings accounts for 83% of the total mass of the brick. The compressive strength of the brick is up to 16.1 MPa, bending strength 3.8 MPa, and with low drying shrinkage and good freeze–thaw resistance. Some factors influencing the mechanical strength of the brick including forming pressure, forming water content and curing regime, are investigated. The hydration products, freeze–thaw durability and anti-carbonation characteristics of the products are discussed.