Civil Engineering - Concrete Technology - Discussion

Discussion Forum : Concrete Technology - Section 4 (Q.No. 13)
13.
The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than
30 minutes
40 minutes
60 minutes
75 minutes
90 minutes.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
7 comments Page 1 of 1.

Kamran said:   4 years ago
No, On-site, we use some retarders. So it's 90min.

M-Sadiq said:   4 years ago
We know the initial sitting time of ordinary portland cement is 30 minutes but here we are talking about concrete.

Is the initial setting time of concrete and cement past is same by using portland cement?

Please, anyone explain.

VIVEK SINGH said:   7 years ago
@Amitesh ji,

How it came 'not more than 60 min'?

Amitesh said:   8 years ago
If it was less than 30 min is correct, here 60 min is the correct answer. Initial settings time is not less than 30 min and not more than 60 min for Portland cement.

Pankaj said:   9 years ago
The intial setting time is 30 min that y.

Krishna said:   10 years ago
Retarders are used to delay or extend the setting time of cement paste in concrete. These are helpful for concrete that has to be transported to long distance, and helpful in placing the concrete at high temperatures.

Eg: Calcium Ligno-sulphonates and Carbohydrates derivatives.

AMIT JAISWAL said:   10 years ago
How this is possible for places which are more than 1 hr away from any batching plant?

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