GGBS (Ground Granulated Blast furnace Slag) is a vitrified substance that is a byproduct of iron production in a blast furnace. It consists primarily of oxides of calcium, silicon, aluminum and magnesium.
GGBS makes durable concrete structures with ordinary Portland cement and other pozzolanic materials. With the help of GGBS transportation, GGBS has been widely used in Europe and increasingly in the United States and Asia (particularly in Japan and Singapore) for its superiority in concrete durability, extending the lifespan of buildings from fifty years to a hundred years. 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% and in the production of ready-mixed or site-batched durable concrete. Concrete made with GGBS cement sets more slowly than concrete made with ordinary Portland cement, depending on the amount of GGBS in the cementitious material, but also continues to gain strength over a longer period in production conditions. This results in lower heat of hydration and lower temperature rises, making avoiding cold joints easier, but may also affect construction schedules where the quick setting is required.
Since GGBS is a byproduct of the steel manufacturing process, its use in concrete improves the project’s sustainability and adds points towards the certification. In this respect, with GGBS transportation, GGBS can also be used for superstructure and the cases where the concrete is in contact with chlorides and sulphates. This is because the slower setting time for casting the superstructure is justified.
Use and benefits of Ground Granulated Blast Furnace Slag
For building projects where durable and sustainable concrete is key, GGBS is the ideal solution. Using this product in your construction process will offer you:
- Durability; GGBS reduces the likelihood of concrete thermal cracking, improving concrete’s resistance to damage from alkali-silica reaction, sulphates and chlorides. Concrete in aggressive environments is much more durable, with GGBS as a partial replacement for the cement.
- Sustainability; produce low CO2 concrete with low levels of embodied CO2. GGBS is also actively helping reduce the amount of industry byproduct material going to landfills. It helps to make greener cement by reducing the embodied carbon.
- Aesthetic finish; a much lighter coloured concrete finish can be achieved compared to Portland Cement-based concrete. GGBS also helps improve the reflectivity of finished materials (improving safety in dark environments) and contributes to reducing crystalline deposits on concrete surfaces.
On its own, GGBS hardens slowly and, for use in concrete, it needs to be activated by combining it with an activator. The reduction in early strength will be more noticeable at high GGBS levels and low temperatures. Similarly, the reduction will be magnified with low cement content concrete, kerb backing, etc.
Under normal circumstances, the striking times for concretes containing up to 50% GGBS do not increase sufficiently to affect the construction programme significantly. However, concrete with higher levels of GGBS will not always achieve sufficient strength after one day to allow removal of vertical formwork, particularly at lower temperatures, lower cementitious contents and in thinner sections.
So, contact a GGBS transportation service and get it delivered to you as it can prove beneficial to you.