Sunday, 9 April 2017

Interviews and Exams questions : ALL About Cement


1: Name the component that responsible for early strength of concrete:

Ans: C3S ( Tri Calcium silicate ) , that react with water and produces more heat of hydration is responsible for early strength of concrete.


2: Which compound contribute to the later strength of concrete ?
Ans: C2S ( Di Calcium silicate ) that hydrates slowly , contribute to the later strength of concrete .


3: After how many days , the compressive strength developed by C3S and C2S are equal .
Ans: ONE year  

4:For road rapid work which type of cement is recommended :
Ans: Rapid hardening cement

5: In how many  days , about 50% of the total heat evolution occurs.
Ans: During the first 3 days of hydration 

6:Which oxides are responsible for high early strength of cement ?
Ans: High total alumina and high ferric oxide content favour the production of high early strength in cement


Compounds : When components of cements added up with water than they called compound in simple language ..


Tricalcium Silicate (C3S) hardens rapidly and is largely responsible for initial set and early strength.


In general, the early strength of portland cement concrete is higher with increased percentages of C3S.


Dicalcium Silicate (C2S) hardens slowly and contributes largely to strength increases at ages beyond 7 days.


Tricalcium Aluminate (C3A) liberates a large amount of heat during the first few days of hardening and, together with C3S and C2S may somewhat increase the early strength of the hardening cement (this effect being due to the considerable heat of hydration that this compound evolves). It does affect set times.


Tetracalcium Aluminoferrite (C4AF) contributes very slightly to strength gain. However, acts as
a flux during manufacturing. Contributes to the color effects that makes cement gray.aakes cement gray.

Compounds by percentage :



Role of compounds on properties of cement : MOST IMP




Next Article will be : Types of cement and difference between OPC , PPC cement , Where and when they will use .... Many more.... soon.....




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