Tata ground granulated blast furnace slag, Packaging Size : 50 Kg

Ground Granulated Blast Furnace Slag (GGBFS): A Comprehensive Product Description

Introduction

Ground Granulated Blast Furnace Slag (GGBFS) is a high-performance, eco-friendly construction material derived from the by-products of the iron-making process. It is an industrial by-product that is formed when molten blast furnace slag is rapidly quenched with water or air to create a glassy, granular material. These granules are then ground into a fine powder, resulting in GGBFS. Widely used in construction, GGBFS is recognized for its remarkable strength, durability, and environmental benefits, making it an integral part of modern construction technologies, especially for sustainable development.

Production Process of GGBFS

GGBFS originates from the blast furnace process used to extract iron. In this process, raw materials such as iron ore, limestone, and coke are subjected to high temperatures in the blast furnace. The molten iron collects at the furnace's base, while the lighter slag floats on top. This slag, a mixture of lime, silica, alumina, and magnesia, is rapidly cooled using high-pressure water or air jets.

The rapid cooling process—referred to as quenching—prevents crystallization, resulting in a granular material with a glassy, amorphous structure. These granules are dried and finely ground to produce GGBFS, which exhibits cementitious and pozzolanic properties.

Chemical Composition

The chemical composition of GGBFS is similar to that of Portland cement but with variations that give it unique characteristics. It typically contains:

• Calcium Oxide (CaO): 30-50%
• Silicon Dioxide (SiO₂): 28-38%
• Aluminum Oxide (Al₂O₃): 8-18%
• Magnesium Oxide (MgO): 1-15%
• Trace amounts of iron oxide, manganese, and sulfur compounds.

This composition allows GGBFS to participate in hydration reactions, enhancing the performance of cement and concrete when used as a supplementary cementitious material (SCM).

Properties of GGBFS

1. Physical Properties

   • Appearance: GGBFS is a fine, off-white powder.
   • Density: It has a specific gravity of 2.8–3.0 g/cm³.
   • Fineness: The fineness of GGBFS typically ranges between 400 and 600 m²/kg, which ensures high reactivity.

2. Mechanical Properties

   • GGBFS enhances the compressive and tensile strength of concrete over extended curing periods.
   • It improves the elasticity and reduces shrinkage in concrete structures.

3. Chemical Properties

   • GGBFS reacts with calcium hydroxide released during the hydration of Portland cement to form additional calcium silicate hydrate (C-S-H), improving the concrete's strength and durability.

4. Thermal Properties

   • GGBFS reduces the heat of hydration in concrete mixes, making it ideal for mass concrete applications where thermal cracking is a concern.