Use and Properties of Blast Furnace Slag as a Building Material- A Review
Authors: Jain Mohit 
Published: November 2014

This paper aims at bringing a literature review on the uses and properties of popular industrial and mineral byproduct slag. At the present, most industrial slags are being used without taking full advantage of their properties or disposed rather than used. The use of slag in replacing Portland cement by GGBFS is not very common. The industrial slags, which have cementitious or pozzolanic properties, should be used as partial or full replacement for Portland cement rather than as bulk aggregates or ballasts because of the high cost of Portland cement, which is attribted to the high energy consumption for the production of Portland cement. The traditional way to utilize metallurgical slags in cementing materials is to partially replace Portland cement. The practice of using such mineral admixtures in construction will reduce the need of portland cement and its use in various parts of the world, thus greatly reducing the amount of pollution and pave a way for a cleaner and more economical construction material, of which India is in a great need.

The literary investigation was carried out on different forms of slag used in construction, i.e. slag aggregates, ground granulated blast furnace slag (GGBFS) and slag mixed with clinker in cement production. Many different properties were examined during the literature review, all segregated into separate categories based on the type of usage, particle size, chemical composition and amount of usage. The base samples ranged from cement sample to concrete cubes. The properties investigated from various sources of literature were compressive strength, flexure strength, duability, abrasion resistance, drying shrinkage, reactivity, hydraulic power, hydration and slump loss. Also properties related to environmental effects like cabonation depth, chloride resistance, sulphate resistance, percentage of water absorption, heat resistance and resistance to freeze and thaw cycles. Its activation with innovative methods and certain reasons were found out which attributed to such behaviour such as glass content, microstructure, pH nature, pore size etc.

The behaviour of concrete samples were also investigated with some agents, i.e. samples with some extra chemical admixtures, air entraining agents, and several other mineral and pozzolanic admixtures like fly ash and Rice husk ash. The performance of Slag in different situations ( like its use in reinforced concrete ) and environment (like corrosive sea or marine environment ) was also found out and compared to control concrete. Also differentiation was done on the basis of formation of slag aggregates, i.e. the variation in properties of slag based construction materials vary when slag is created employing different techniques. The investigation will also explain the different problems faced by civil engineers in using slag as a major component in building materials. The review will also explore the future of polyblended cements constituting slag as the main constituent and its scope to be used with agricultural byproducts like Rice Husk ash, or surkhi and other industrial byproducts like fly ash.