Table of Contents
What is the initial time of setting cement?
The time elapsed between the moments when water is added to the cement to the time when the square needle penetrates a depth of 33 to 35 mm from the top of the mould is known as the Initial Setting Time of that cement. The initial Setting Time should not be less than 30 minutes for Ordinary Portland Cement.
What are the initial and final setting times of cement?
Initial Setting Time of Cement = 7:45 am – 7:00 am = 45 min. Final setting Time of Cement = 12:00 pm – 7:00 am = 5 hr = 300 min.
Why is the initial setting of cement 30 minutes?
In this time cement can be molded in any desired shape without losing its strength. This is the time at which the hardening of the cement starts and the only time available for mixing the paste and placing it in position. if this time less then 30 min then can’t molded in any shape in many situations.
What is initial time?
Initial setting time is the time when the paste starts losing its plasticity. Initial setting time test is important for transportation, placing and compaction of cement concrete. It is the time taken for the cement paste or cement concrete to harden sufficiently and attain the shape of the mould in which it is cast.
What is the importance of setting time of cement?
Initial setting time test of cement is important for transportation, placing and compaction of cement paste. Determination of initial setting time duration is required to delay the process of hydration or hardening.
What is the initial setting time and 3 days strength of Portland cement?
2. Initial setting time shall not be less than 30 minutes and final setting time should not be more than 10 hours. 3. Soundness lies from 5 to 10 mm when calculated from Le-Chatelier’s method.
What is initial setting time for cement Mcq?
8. What is the initial setting time of cement? Explanation: As per IS code 4031-part 5, the initial setting time of cement is minimum of 30 minutes.
What are the factors responsible for setting time of concrete?
Setting of concrete is based or related to the setting of cement paste. Thus cement properties greatly affect the setting time. Following are the factors that affect the setting of concrete. 1. Water Cement ratio
What is the initial setting time of concrete?
The initial setting time of concrete is 30 min. The process of setting starts immediately after preparation of concrete. Within 10 min. after preparation it can be used. Other wise it become hard and can not take the shape of form work.
What is the significance of setting time of cement?
Setting time is basically the time required for stiffening of cement to a defined consistency. The importance thing to remember is that it’s essential that cement should not set too rapidly as it may lead to insufficient time to transport and place the concrete before it becomes too hard.
What is initial and final setting time in cement?
Generally, the initial setting time of cement is in the range of 30 to 45 minutes . When the cement completely loses its plasticity, it is known as the final setting time. The time gap between the water addition to complete loss of cement plasticity is known as the final setting time. The maximum setting time of cement should not exceed 10 hours.