Research initiatives on the influence of wollastonite in cement-based construction material- A review

Many materials have been tried and tested as partial replacement of cement in concrete, either waste by-product of any manufacturing process or abundant mineral. Materials commonly used as partial replacement of cement are fly ash, ground granulated blast furnace slag (GGBFS), silica fume, bagasse ash, foundry ash, wollastonite, metakaolin, and so on. A significant issue with concrete is its brittleness (weak flexural strength), and this brittleness could be reduced by providing fibers into the concrete to increase its tensile capacity. Here, we will extensively discuss wollastonite and its various effects on concrete as partial replacement of cement or sand. Mines of Wollastonite is available in Rajasthan, Andhra Pradesh, Tamil Nadu, and Uttarakhand. In 2017, India was the second-largest producer of wollastonite after China. Wollastonite is used as microfibre; hence they increase the flexural strength of the concrete. It also reduces drying-shrinkage, abrasion loss, water absorption, and enhances concrete durability due to sulfate attack. It has been found that wollastonite-fly ash and wollastonite-micro silica combinations densify concrete at high replacement levels, thereby improving the mix’s strength and durability characteristics. When using recycled waste ceramic aggregates (RWCA) in concrete, strength, and workability are maximum at 30% replacement of cement by wollastonite.