Is fly ash and bottom ash the same?
Fly ash particles are the lightest kind of coal ash—so light that they “fly” up into the exhaust stacks of the power plant. Bottom ash is the coarser component of coal ash, comprising about 10 percent of the waste. Rather than floating into the exhaust stacks, it settles to the bottom of the power plant’s boiler.
What is the percentage of fly ash?
The replacement of cement by fly ash reduces the water demand for a given slump. When fly ash is used at about 20 percent of the total cementitious, water demand is reduced by approximately 10 percent….Benefits to Hardened Concrete.
| (hydration) | ||
|---|---|---|
| Pozzolanic Reaction: | CaOH + | S → C-S-H |
| silica from ash constituents |
What is the density of bottom ash?
The bulk density of the bottom ash is 2.53 g/cm3 is higher than quicklime but closed to silica.
What is the composition of fly ash?
Fly ash is predominately composed of silica, aluminum, iron, calcium, and oxygen, but the particles may also contain heavy metals such as arsenic and lead at trace levels.
What is the maximum size of fly ash?
1000μm
Explanation: Fly ash is a finely divided particle produced from the combustion of coal. Its maximum size is 1000μm.
What is the maximum size of fly ash is?
What is the specific gravity of fly ash?
2.1 to 3.0
The specific gravity of fly ash usually ranges from 2.1 to 3.0, while its specific surface area (measured by the Blaine air permeability method)(6) may range from 170 to 1000 m2/kg. The color of fly ash can vary from tan to gray to black, depending on the amount of unburned carbon in the ash.
What is the specific gravity of bottom ash?
Specific Gravity: The specific gravity of bottom ash usually ranges from 2.1 to 2.7,(10) but values as low as 1.9 and as high as 3.4 have been recorded(11). Bottom ash with relatively low specific gravity (below 2.2) is often indicative of the presence of porous popcorn particles.
What is LOI in fly ash?
LOI is a measurement of unburned carbon (coal) remaining in the ash and is a critical characteristic of fly ash, especially for concrete applications.
How do you mix fly ash for concrete?
For obtaining the best result the fly ash concrete should be prepared by the following mixing method: About 3/4th quantity of the mixing water be taken in the concrete mixer. Weighted amount of the required quantity of fly ash then added to it and mixed for 30 sec.
How much fly ash can be used in concrete as per IS code?
The fly ash added in ppc should not be less than 15% and not more than 35%. According to IS code you can replace portland cement by max 35% of fly ash content. Many people tried replacing opc with 50% or more using fly ash – it termed as high volume fly ash concrete (HVFC).