USE OF BLAST FURNACE SLAG IN CONCRETE

Abstract

Concrete is a composite material composed mainly of water, aggregate, and cement. Often, additives and
reinforcements (such as rebar) are included in the mixture to achieve the desired physical properties of the finished material.
When these ingredients are mixed together, they form a fluid mass that is easily molded into shape. Over time, the cement
forms a hard matrix which binds the rest of the ingredients together into a durable stone-like material with many uses. It can
be used easily in any shape and size of structural member. The main ingredients of concrete are cement, sand and aggregate.
So concrete can be considered to be an artificial stone obtained by binding together the particles of relatively inert coarse
and fine materials with cement paste. The aggregates are cheaper than cement and impart greater volume durability and
stability to concrete. Primarily for the purpose of providing bulk to the concrete the aggregate is used. The aggregate
provides about 70-75% of the body of the concrete and hence its influence is extremely important. The stone aggregate
produced by crushing of stone obtained from mountains. The quarrying of stone causes number of the aggregate is used for
environmental problem. Hence to replace these aggregate by slag not only allow the use of waste product but also avoid
environmental problem. Slag is a waste produced during manufacturing of pig iron and steel. It consists of oxides of calcium,
magnesium, manganese, aluminum, nickel and phosphorous. The physical properties of slag depends upon change in process
of cooling, however the chemical composition remain unchanged. The slag produced in blast furnace during pig iron
manufacturing is called blast furnace slag and slag produced at steel melting plant is known as steel slag. Large amount of
industrial waste produced every year in developing countries. Total world steel production crossed 1200 million metric tons.
In India, Slag output obtained during pig iron and steel production is variable and depends on composition of raw materials
and type of furnace. For ore feed containing 60 to 65% irons, blast furnace slag production ranges from about 300 to 540 kg
per ton of crude iron produced.