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gypsum increase the setting time of cement.
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∙ 12y ago
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What is the importance of setting time of cement?
because when we know the setting time of cement we easily identified that where can we use the cement according to there setting time.
What are the factors affecting the initial setting time of cement?
When cement is mixed with water, it forms slurry which gradually becomes less plastic with the passage of time & finally a hard mass is obtained. In this process, at a certain stage when the cement paste is sufficiently rigid to withstand a definite amount of Pressure, it is said to have set & the time required to reach this stage is termed as "setting time".
What is vicat apparatus used for?
vicats apparatus is used for initial setting time of cement.
What is initial and final setting time in cement according to ASTM?
Using a Vicat needle, the ASTM determined time for initial concrete setting is equal to or greater than 45 minutes. They set the final setting time is equal to or greter than 375 minutes.
What is the importance of standard consistency test?
by standard consistency test we determine standard consistency of cement which is denoted by p. as we know standard consistency value for a cement its value is used for making the paste for determining setting time, soundness, compressive strength of cement
Why 2 of gypsum is added to cement?
Gypsum is added to cement to decrease the setting time.
Why 2 gypsum is added in the cement?
The construction industry uses both the natural and the synthetic forms of gypsum in Portland cement manufacturing. Although the amount of gypsum used in the mix represents a small percentage of the volume of all ingredients, gypsum has important functions.
What is the effect on setting time of cement if water added is less or more than 85 percent of normal constituency of cement?
how the water mixed with cement affects the time of its setting
What are the name of admixture that effect on the setting time of cement?
retarder increases time to set, accelerator decreases setting time
What is the importance of setting time?
because when we know the setting time of cement we easily identified that where can we use the cement according to there setting time.
What is the function of gypsum in cement?
Gypsum is a mineral that contains up to 88% CaSO4.2H2O. this compound Calcium Sulphate dihydrate is responsible for retarding the setting time of cement. the action of Calcium Sulphate dihydrate is such that it inhibits the speed at which Calcite (C3S) molecules bind with water to set thus creating a cement that is workable.
Can you reuse the cement after it has crossed its setting time?
yes, if it is before the initial setting time...
What is the importance of setting time of cement?
because when we know the setting time of cement we easily identified that where can we use the cement according to there setting time.
What is the final setting time if cement?
initialy setting time up to 10min. & final setting time upto 10 hours
What is initial setting time of cement?
It's the time from which cement starts the setting process after water is added.. Usually it is 30 min.. It can be delayed or advanced using chemicals..
What are the factors affecting the initial setting time of cement?
When cement is mixed with water, it forms slurry which gradually becomes less plastic with the passage of time & finally a hard mass is obtained. In this process, at a certain stage when the cement paste is sufficiently rigid to withstand a definite amount of Pressure, it is said to have set & the time required to reach this stage is termed as "setting time".
What is initial Setting time?
An arbitrary division has been made for the setting time of cement as initial setting time and final setting time.It is difficult to draw a rigid line between these two arbitrary divisions.For convenience,initial setting time is regarded as the time elapsed between the moment that the water is added to the cement,to the time that the paste starts losing its plasticity.The final setting time is the time elapsed between the moment that the water is added to the cement ,and the time when the paste has completely lost its plasticity and has attained sufficient firmness to resist certain definite pressure.
