What is Ggbs in concrete used for?
Ground Granulated Blast Furnace Slag (GGBS) is a cement substitute that improves durability and also the environmental credentials of concrete mixes. It is a by-product of the iron-making industry.
Is Ggbs cheaper than cement?
As GGBS cement is slightly less expensive than Portland cement, concrete made with GGBS cement will be similarly priced to that made with ordinary Portland cement. It is used partially as per mix ratio.
What is the difference between fly ash and Ggbs?
Fly ash is low in calcium oxide content but rich in silica and alumina while GGBS is relatively high in calcium oxide. The combination of these two materials can be more beneficial when used as a stabilizing agent than using them individually.
What is PBFC concrete?
Portland Blastfurnace Cement (PBFC) is a homogeneous blend of Ordinary Portland cement (OPC) and Ground Granulated Blastfurnace Slag (GGBS/GGBFS), complying with SS EN 197-1, BS 146 and SS 477, and suitable for use when moderate sulfate resistance or moderate heat of hydration is desired.
What are disadvantages of Ggbs?
Disadvantages of Ground Granulated Blast Furnace Slag (GGBS) in Concrete
- Additional quality control costs.
- Slow and small hydration heat, not suitable in precast factories or during winter concreting.
- Faster carbonation rate decreased service life span due to reinforcement corrosion.
What is Ggbs made from?
GGBS is an industrial byproduct obtained when iron ore, limestone, and coke heated to a temperature of about 1500°C in the furnace. The formation of molten slag includes the mineral constituents such as aluminates, silicates, calcium oxide, etc.
How much Ggbs can be used in concrete?
GGBS proportions
A typical combination is 50% GGBS with 50% CEM I, but percentages of GGBS anywhere between 20 and 80% are commonly used. The greater the percentage of GGBS, the greater will be the effect on concrete properties.
Is Ggbs sustainable?
GGBS (Ground Granulated Blast-furnace Slag) is one of the ‘greenest’ of construction materials. Its only raw material is a very specific slag that is a by-product from the blast-furnaces manufacturing iron. Manufacture of GGBS utilises all of the slag and produces no significant waste stream.
What is Ggbs list its advantages?
GGBS can be used as a partial replacement of OPC cement in concrete production at batching plants. It is highly cementitious and high in calcium silicate hydrates (CSH) which is a strength enhancing compound which improves the strength, durability and appearance of the concrete.
Is Ggbs a admixture?
GGBS is mainly used as a partial replacement of cement in concrete. When added as an admixture to concrete, it acts as a stabilising agent and improves the quality of concrete.
Does fly ash increase concrete strength?
Fly ash use in concrete improves the workability of plastic concrete, and the strength and durability of hardened concrete. Fly ash use is also cost effective. When fly ash is added to concrete, the amount of portland cement may be reduced. Benefits to Fresh Concrete.
Why slag is used in cement?
The advantage of slag is its ability to substitute more of cement. Giving savings of up to 9% in cement cost with a 50% slag to cement content ratio. With the combination of both cost savings and strength increase, SCMs such as fly ash and slag should always be considered for certain applications.
Is Ggbs a cement?
GGBS (Ground Granulated Blast-furnace Slag) is a cementitious material whose main use is in concrete and is a by-product from the blast-furnaces used to make iron.
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Typical chemical composition.
| Calcium oxide: | 40% |
|---|---|
| Silica: | 35% |
| Alumina: | 13% |
| Magnesia: | 8% |
How do you mix Ggbs with cement?
On its own GGBS hardens slowly and, for use in concrete, it needs to be activated by combining it with an activator (typically Portland cement CEM I but alkali activation is also used). A typical combination is 50% GGBS with 50% CEM I, but percentages of GGBS anywhere between 20 and 80% are commonly used.
Does Ggbs increase strength?
GGBS concrete gains more strength than the PC concrete after the age of 28 day till 56 day. The mechanical properties of blended concrete for various levels of cement replacement have been observed as higher than control concrete mix having no GGBS.
Is Ggbs a waste product?
As fly ash & Granulated Blast Furnace Slag (GGBS) is waste product obtained by coal & steel industry respectively.
Where is Ggbs used?
GGBS (Ground Granulated Blast-furnace Slag) is a cementitious material whose main use is in concrete and is a by-product from the blast-furnaces used to make iron. Blast-furnaces operate at temperatures of about 1,500°C and are fed with a carefully controlled mixture of iron ore, coke and limestone.
How Ggbs is produced?
Production. GGBS is produced by grinding Granulated Blastfurnace Slag to a controlled fineness. There are a number of different methods of grinding granulated blastfurnace slag. Traditionally, standard ball mills have been used, but since the early 2000s the use of roller presses and vertical mills has increased.
What are the disadvantages of fly ash?
Disadvantages
- Slower strength gain.
- Seasonal limitation.
- Increased need for air-entraining admixtures.
- Increase of salt scaling produced by higher proportions of fly ash.
What are the problems with fly ash?
Inhalation or ingestion of the toxins in fly ash can have impacts on the nervous system, causing cognitive defects, developmental delays, and behavioral problems while also increasing a person’s chance of developing lung disease, kidney disease, and gastrointestinal illness.
Is slag better than cement?
What are the disadvantages of slag?
Disadvantages of Blast-Furnace Slag Cement
Early Strength is low; therefore, it cannot be used in Reinforced Cement Concrete (RCC) works. As the initial setting time is high, this cement is not used for emergency or repair works.
Is Ggbs environmentally friendly?
Why fly ash concrete is not commonly used?
Disadvantages of Fly Ash
The quality of fly ash can affect the quality and strength of Cement concrete. Poor quality fly ash can increase the permeability of the concrete and cause damage to the building.
Is fly ash cheaper than cement?
Because fly ash is less expensive than cement, mixes containing it are usually a bit less expensive than their straight cement counterparts. Fly ash mixes are often called “performance mixes”, so-called because of how they perform.