Civil Engineering - Building Materials - Discussion
Discussion Forum : Building Materials - Section 1 (Q.No. 11)
11.
The initial setting time of lime-pozzolana, is
Discussion:
52 comments Page 3 of 6.
Souhard bhati said:
7 years ago
Aluminum has a quick setting quality when mixed as raw material then how high alumina cement has more setting time as compared to opc, Even the aluminum amount is high.
Civil era said:
7 years ago
Pozzolana material particles size is less than 90micron, it does not have any cementing property but shows when it contact with water due to overgrinding (i.e less than 90micron) its rate of hydration increases but less heat of hydration so it shows large initial setting time but in question lime-pozzolana (it means it is a gauged cement) lime also show setting property also some time addition of water.
Rohith said:
8 years ago
I am not getting it, Give me the explanation.
Taimoor Nasir said:
8 years ago
The calcium hydroxide reacts with the carbon dioxide in the atmosphere to give calcium carbonate that gains cementing properties (Carbonation) as their is low CO2 in air thats why it takes Longer time to Set than OPC which uses water for Setting ! And probably that is why Lime Cement is not used in Under water Structures due to Absence of C02.
Jack dcruz said:
8 years ago
Why it's initial setting time more than to opc?
Yashwanth said:
8 years ago
Initial setting time should be less than 70 mins.
AsaiAnu said:
9 years ago
Initial time 30 minutes opc.
Pappukumar said:
9 years ago
OPC initial time 30 minutes.
Krishna said:
9 years ago
Ordinary Portland Cement (OPC) is graded according to their strength. The grade indicates the compression strength (mpa) of the concrete that will attain after 28 days of setting.
Subir said:
9 years ago
What is the difference between the grade 40, 53, 33, etc?
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