Conclusion – Initial and final setting time of cement are very important properties of cement, which are responsible for the quality of concrete and mortar. Hence it is advisable to check the initial setting time and final setting time of cement before you use it for the construction work.
- 0.1 What is initial setting time for cement?
- 0.2 What is initial & final setting time of cement?
- 1 What is normal setting of cement?
- 2 What is the setting time of Ultratech cement?
- 3 What is initial setting time of cement Mcq?
- 4 Why initial setting time is important?
- 5 What is a good cement ratio?
- 6 What is the initial setting time of OPC?
- 7 What is the initial setting time of cement Nptel?
- 8 Which type of cement has a final setting time of 30 minutes?
- 9 What causes initial setting of cement?
What is initial setting time for cement?
The setting of cement starts within 5 minutes after addition of water and it becomes hard like stone in less than 30 minutes or so.
What is initial & final setting time of cement?
Initial and Final Setting Time of OPC Cement? For OPC, the Minimum setting initial setting is 30 min and the maximum final setting time is 600 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 normal setting of cement?
Final setting time of Cement:- – The time at which cement completely loses its plasticity and became hard is a final setting time of cement. Or The time taken by cement to gain its entire strength is a Final setting time of cement. For Ordinary Portland Cement, The Final Setting Time is 600 minutes (10hrs).
What is the setting time of Ultratech cement?
Cure the concrete for a minimum of 10 days in normal weather conditions,. During hot weather (greater than 40°C), cure the concrete for a minimum of 14 days.
What is initial setting time of 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.
Why initial setting time is important?
FAQs – What is initial setting time of cement? The initial setting time of concrete is the time when cement paste starts hardening after adding water. It is the time period between the addition of water to cement till the time at 1 mm square section needle fails to penetrate the cement paste, placed in the Vicat’s mold 5mm to 7mm from the bottom of the mold.
What is final setting time of cement? Final setting time is that time period between the time water is added to cement and the time at which 1 mm needle makes an impression on the paste in the mould but 5 mm attachment does not make any impression. What is the need for determining initial and final setting time of cement? Initial setting time is the time when the paste starts losing its plasticity.
The test is important for transportation, placing and compaction of cement concrete. Initial setting time duration is also required to delay the process of hydration or hardening. Final setting time is the time when the paste completely loses its plasticity.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.
Why gypsum is added in cement?
Gypsum is added to control the ‘setting of cement’. If not added, the cement will set immediately after mixing of water leaving no time for concrete placing.
What is a good cement ratio?
In terms of the ratio for concrete, it depends on what strength you are trying to achieve, but as a general guide a standard concrete mix would be 1 part cement to 2 parts sand to 4 parts aggregates. For foundations, a mix of 1 part cement to 3 parts sand to 6 parts aggregates can be used.
What is the initial setting time of OPC?
Initial setting time should not be less than 30 minutes and final setting time should not be greater than 600 minutes as per IS 12269.
Which grade cement is used for RCC?
43 Grade Ordinary Portland Cement (OPC 43) – OPC 43 cement shall conform to IS:8112-1989 and the designed strength of 28 days shall be minimum 43 MPa or 430 kg/sqcm. Even though 43 Grade cements’ early strength is less as compared to that of 53 Grade, with time it will attain the same ultimate strength as that of 53 Grade cement.
- In the case of 43 Grade cement, the initial setting of cement is slower as compared to 53 Grade cement.
- In other words, the hydration process and consequently, the release of heat is moderate and therefore, occurrence of micro cracking is much less and can be easily controlled by proper curing of the concrete / masonry work.
Unless a project requires very high strength cement, the use of 43 Grade OPC is generally recommended in general civil construction work such as residential, commercial and industrial structures. It is used in RCC works, preferably where the grade of concrete is up to M-30.
- It is also extensively used in the manufacture of pre-cast items such as blocks, pipes, tiles etc., and also in asbestos products such as sheets and pipes.
- Since OPC 33 has mostly been phased out in the country, OPC 43 is nowadays largely used in plastering, flooring and other non structural applications where OPC 33 was earlier being used.
The physical and chemical characteristics of OPC 43 Grade Deccan Cement very comfortably meets BIS requirements. Particularly, the compressive strength of Deccan Cement OPC 43 is significantly higher than the standards specified by BIS.
Which cement grade is better 43 or 53?
OPC 53 sets quicker than OPC 43 and has a quite low initial setting time. It is used in structures where rapid strength gain is required like large load bearing structures like bridges, huge buildings, etc. OPC 43 on the other hand doesn’t set so quickly and has a normal initial and final setting time.
What is the initial setting time of cement Nptel?
For an ordinary portland cement, the initial setting time should not be less than 30 minutes while the final setting time should not be more than 600 minutes.
What is the initial setting time of cement 15 minutes 30 hours 1 hour 30 minutes?
Initial setting time should not be less than 30 minutes and final setting time should not be greater than 600 minutes as per IS 12269.Q.
Which type of cement has a final setting time of 30 minutes?
|Kamran Iqbal said: (Nov 15, 2019)
|OPC:(Ordinary Portland cement) Initial setting time = 30 min. Final setting time = 10 hours. LPC:(Lime pozzolana cement) Initial setting time= 120 min (2 hours). Final setting time = 6 hours. High alumina cement: Initial setting time= 3.5 hours. Final setting time= 5 hours.
Why setting time of cement is important?
Importance of Initial And Final Setting Time – After mixing cement with water, placing the cement paste in a position requires time. Initial setting time plays an essential role in the strength of cement or concrete. In the case of ordinary Portland cement, the cement paste or concrete must be placed before crossing the initial setting time.i.e., 30 minutes and should not be disturbed until it meets the Final setting time, i.e., 600 minutes,
- The cement should not be set too fast and not be too slow. If it set rapidly, it doesn’t offer sufficient time for transportation and placing of the concrete. While if it is set too late, it can slow down the work and might be postponed due to less strength at the desired time.
- The setting of cement should not be compared with hardening. It is a mechanical strength gained after a specific time interval to resist the penetration of a special attachment dropped into it.
- Initial setting time is essential to transport, placing and compaction of concrete.
- Initial setting time is necessary to delay the hydration process and hardening.
- Final setting time helps to remove shuttering or formwork safely.
- Cement completed its chemical reaction with water till the final setting time.
What causes initial setting of cement?
Tricalcium Aluminate (C3A) – It is responsible for the initial setting time, high heat of hydration and has greater tendency to volume changing causing cracking.