GGBFS, or what is known as ground granulated blast furnace slag, is considered one of the most important materials used instead of traditional cement, thanks to its properties and advantages, and its importance in the components of the concrete mix. GGBFS is mostly added to reduce the cost of concrete. Below we will learn more about its concept, its different types and grades, in addition to its distinctive uses.
GGBFS concept
(GGBFS) or ground granulated blast furnace slag is considered a by-product produced during the ironmaking process in the blast furnace, where the furnace is fed with a mixture of iron ore, coke, and limestone, and these materials are then exposed to very high temperatures of up to 1500 and 1600 degrees Celsius, which leads to their melting.
During the iron production process, the molten slag separates and floats to the surface of the molten iron.
With the development of modern smelting and enrichment technologies, the amount of slag produced per ton of iron ore has decreased significantly, and the properties and composition of the slag vary based on the raw materials used and the smelting methods, which is clearly reflected in the diversity of its quality.
The most prominent types and grades of GGBFS (Granulated Granulated Blast Furnace Slag)
There are many types and grades of high-grade granulated blast furnace slag, and each grade is widely used in various construction applications, especially in the concrete and cement industry, due to its role in enhancing durability and reducing carbon emissions.
The following are the GGBFS grade classifications:
Grade 80
Grade 80 granulated blast furnace slag (GGBFS) with low pozzolanic activity is suitable for applications that do not require high mechanical performance or extreme resistance to environmental factors.
This grade is typically used in projects with simple requirements, such as producing non-load-bearing concrete or improving soil properties in construction. This grade is also an economical option that provides minor improvements in concrete properties while reducing the overall cost, making it suitable for small projects or those that do not face harsh environmental conditions.
Grade 100
The 100 grade of ground granulated blast furnace slag combines good performance with reasonable cost. It is commonly used as a grade of GGBFS to reduce the cost of concrete, improve concrete properties, and minimize cracking that may result from hardening.
In addition, thanks to its moderate pozzolanic activity, it moderately improves the strength of concrete, making it suitable for a wide range of applications, including residential and commercial buildings with moderate mechanical requirements.
Grade 120
Grade 120 is characterized by being the most pozzolanically active and reactive of all GGBFS grades, and is used in high-performance concrete projects that require exceptional mechanical strength and long-term durability, such as bridges, dams, and tunnels.
Grade 120 provides excellent resistance to chemical attack and harsh environments, such as high salinity or sulfate exposure, and is also suitable for applications that require reducing heat generated by the reaction, making it an ideal choice for large concrete structures that require long-term stability and sustainability.
Factors that influence the selection of GGBFS scores:
1- Chemical Composition: The chemical properties of slag are determined based on the proportions of silicon oxide (SiO₂), aluminum oxide (Al₂O₃), and calcium oxide (CaO). The higher the silica content, the higher the pozzolanic activity.
2- Cooling conditions: The quality of the slag depends on the cooling rate after it is extracted from the blast furnaces. Rapid cooling with water produces a highly reactive glassy slag, which is preferred for producing higher grades of GGBFS.
3- Grinding process: The particle size resulting from the grinding process is a key factor affecting the material’s activity. The smaller the particles, the greater the surface area for chemical reactions, thus increasing the pozzolanic activity.
4- The shelf life of slag: Storing slag for a long period before using it may lead to a decrease in its activity due to interaction with atmospheric humidity.
Different applications for each GGBFS grade
1. Grade 80 is used in applications with simple requirements, such as improving the properties of soil or non-load-bearing concrete.
2. Grade 100 is considered ideal for ordinary construction, such as houses or offices.
3. Grade 120 is used in large projects, such as bridges, tunnels, dams, or industrial facilities that require superior performance and long-term durability.
Granulated blast furnace slag (GGBFS) is a versatile material with enhanced properties that vary depending on its grade. Selecting the appropriate grade depends on the project requirements, as this material can significantly improve concrete performance in terms of strength, durability, and cost-effectiveness.
Adding GGBFS to reduce the cost of concrete
Adding GGBFS to reduce concrete costs is one of the most economical solutions used in the construction industry, as it significantly contributes to reducing the overall cost of production. Without affecting performance quality
GGBFS is used as a partial replacement for Portland cement, reducing the amount of cement required, which directly translates to cost reduction, especially in large projects that require huge quantities of concrete.
Key cost reduction benefits of using GGBFS:
1) Reducing the consumption of Portland cement, as Portland cement is one of the most expensive components in concrete, and adding GGBFS in proportions ranging from 30% to 70% significantly reduces the amount used, thus achieving significant financial savings.
2) Reuse of secondary resources, as GGBFS is a by-product of the steel industry, its use in concrete is an efficient investment of resources, making it both an economical and sustainable solution.
3) Despite its lower cost, adding GGBFS improves concrete properties such as reducing heat of hydration, increasing crack resistance, and enhancing durability. This reduces the need for costly future maintenance work.
4) Using GGBFS instead of Portland cement reduces carbon dioxide emissions from the manufacturing process, contributing to environmental sustainability goals and reducing costs associated with compliance with emissions standards.
It should be noted that GGBFS is usually added at a rate of between 20% and 80% of the total cement used in the mix, depending on the project requirements and working conditions. The higher the percentage of addition, the greater the financial savings while maintaining the required concrete properties.
In conclusion, ground granulated blast furnace slag is one of the most important alternatives used. If you are looking for the best companies that can provide you with GGBFS to reduce the cost of concrete or add Microsilica to concrete with the highest possible quality, Smart Care Chemical Trading Company provides this material along with other important building and construction materials, in addition to specialized technical consultations for your construction or engineering project.
Feel free to contact Smart Care Chemical Trading Company via WhatsApp on 0096655388500 For the latest innovative construction solutions, we are here to provide comprehensive consultations and integrated solutions that efficiently and professionally meet the needs of your construction projects.