Tata Steel has launched a new value- added product, a ground granulated blast furnace (GGBS) for the construction industry.
GGBS cement is routinely specified in concrete production to provide protection against both sulphate attack and chloride attack. GGBS has now effectively replaced sulfate-resisting Portland cement (SRPC) in the market for sulfate resistance. The Tata Steel Group will now be offering Ground Granulated BF Slag, straight from its steel plant to the construction industry. Trial supplies of GGBS will be started in a month´s time and based on the market response, a full scale commercial launch can be expected in the next three months. This product will be introduced in other major cities of eastern India like Kolkata, Ranchi, and Bhubaneswar.
An interactive session on the subject was organised with builders, contractors and architects of Jamshedpur city to introduce this product. Suresh Rao, National Head Technical, RMC Ready Mix Bengaluru, who was the guest speaker, gave a detailed presentation sharing his experience of using GGBS and its associated advantages. Sandeep Kumar, EIC (Secondary Products), Tata Steel talked about the benefits of GGBS and promised that Tata Steel as always, will come up with better products at competitive prices. A K Srivastav, Chairman BAI, Jamshedpur, and BN Dikshit, Former President, BAI, encouraged the builders, contractors and the architect community to come forward and use this product which offers substantial cost savings.
GGBS has been widely used in developed economies for years and of late, is also used in major construction projects in India. The product promises to be a sustainable and cost- effective material that will not only increase compressive strength and durability of the concrete but also significantly reduce the carbon footprint.
GGBFS/GGBS is obtained by quenching molten iron slag from a blast furnace in water or steam, to produce a glassy, granular product that is dried and ground into a fine powder. GGBS is used to make durable concrete structures by blending it in ordinary Portland cement and/or other Pozzolanic materials. It has been used in Europe, and is increasingly being used in the United States and in Asia (particularly in Japan and Singapore) for its superiority in concrete durability. It is known to almost double the lifespan of structures.
GGBS protects the structure from damages caused by alkali silica reaction (ASR), provides higher resistance to chloride penetration, protects the reinforcement from corrosion and also provides higher resistance to attacks by sulfate and other chemicals. GGBS is blended with ordinary Portland cement (OPC) in ratio ranging from 30:70 to 70:30 to make ready mix concrete (RMC). Mixing ratio depends on the required strength and nature of the concrete. This cuts down the cement cost in concrete by around 30-40 per cent.
The main components of blast furnace slag are CaO, SiO2, Al2O3, and MgO. In general, increasing the CaO content of the slag results in an increase in compressive strength. Two major uses of GGBS are in the production of quality-improved slag cement, namely Portland blast furnace cement (PBFC) and high-slag blast-furnace cement (HSBFC), with GGBS content ranging typically from 30 to 70 per cent and in the production of ready mixed or site-batched durable concrete.