Ground granulated blast furnace slag

1. Ground Granulated Blast Furnace Slag
Concrete Technology
Prepared by: Ghanashyam prajapati

2. Content
1. Introduction
2. Process
3. Compositions
4. Proportioning concrete containing GGBF slag
5. Effects of GGBFS on properties of fresh
concrete
6. Uses of GGBFS in concrete

3. Ground Granulated Blast Furnace Slag
• Ground Granulated Blast Furnace Slag (GGBFS)
is a by product of the steel industry.
• Ground Granulated Blast furnace slag is the
nonmetallic product, consisting essentially of
silicates and aluminosilicates of calcium and of
other bases, that is developed in a molten
condition simultaneously with iron in a blast
furnace.

4. Process for GGBFS

5. compositions

6. Proportioning Concrete Containing GGBF
Slag
• In most cases, GGBF slags have been used in
proportions of 25 to 70 percent by mass of the total
cementitious material.
• The proportion of GGBF slag should be dictated by
the purposes for which the concrete is to be used.
• Where GGBF slags are blended with Portland
cement, the combination of cementitious material will
result in physical properties.
• For example, as the percentage of GGBF slag
increases, a slower rate of strength gain should be
expected.

7. • The proportion of GGBF slag to be used will depend
on the requirements for temperature rise control, time
of setting and finishing, sulfate resistance, and the
control of expansion due to the alkali-silica reaction.
• For example, where high sulfate resistance is
required, the GGBF slag content should be a
minimum of 50 percent of the total cementitious
material.

8. Effects Of GGBFS On Properties Of
Fresh Concrete
• The cementitious material containing GGBF slags
exhibited greater workability due to the increased
paste content and increased cohesiveness of the
paste.
• Usually, an increase in time of setting can be expected
when GGBF slag is used as replacement for part of
the Portland cement in concrete mixtures.
• GGBF slag is finer than the Portland cement and
is substituted on an equal-mass basis, bleeding is
reduced;
• conversely, when the GGBF slag is coarser, the
rate and amount of bleeding may increase.

9. Effects On Properties Of Hardened
Concrete
• Decrease Strength and rate of strength gain.
• Resistance to freezing and thawing
• Resistance to deicing chemicals
• Resistance to the corrosion of reinforcement
• Reduction of expansion due to alkali-silica
reaction(ASR)
• Resistance to sulfate attack
• Reduce the permeability
• Effects on temperature rise in mass concrete

10. Uses Of GGBF Slag In Concrete
• GGBS is used to make durable concrete structures in
combination with ordinary Portland cement and/or
other pozzolanic materials.
• 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.