Ground granulated blast-furnace slag

**Production and Composition of Ground Granulated Blast-Furnace Slag:**
– Chemical composition varies based on raw materials in iron production process
– Silicate and aluminate impurities combine in blast furnace with flux
– Slow cooling results in unreactive crystalline Ca-Al-Mg silicates
– Granulation process used to cool and fragment slag for suitable reactivity

**Applications of GGBS:**
– Used in Europe, US, and Asia for durable concrete structures
– Major uses include quality-improved slag cement and ready-mixed durable concrete
– Sets slower than ordinary Portland cement, providing lower heat of hydration
– Reduces risk of damages from alkali-silica reaction and reinforcement corrosion
– Provides higher resistance to chloride ingress and attacks by sulfate and other chemicals

**GGBS Cement Uses and Benefits:**
– Added to concrete as replacement for Portland cement
– Replacement levels vary from 30% to 85%, with typical use between 40% to 50%
– Provides durability against sulfate and chloride attack
– Offers near-white color for exposed fair-faced concrete finishes
– Concrete with GGBS has higher ultimate strength than Portland cement

**Architectural and Engineering Benefits of GGBS:**
– Bulk Electrical Resistivity test indicates higher durability with GGBS
– Helps limit temperature rise in large concrete pours, reducing thermal gradients
– Prevents efflorescence and staining of concrete surfaces
– Recognized by LEED and BEAM Plus for sustainability
– Optimal GGBS dosage in concrete is 20-30% by mass for higher compressive strength

**Sustainability and External Resources on GGBS:**
– By-product of steel manufacturing, improving project sustainability
– Can be used for superstructure and in chloride/sulfate contact cases
– Various citations and studies on GGBS performance in concrete
– External links for more information and resources on GGBShttps://en.wikipedia.org/wiki/Slag_cement