If p is the standard consistency of cement, the amount of water used in conducting the initial setting time test on cement is
- A0.65 p
- B0.85 pCorrect
- C0.6 p
- D0.78 p
Solution
Concept
Water requirement for cement setting time test
Formula
NONE
Step-by-step solution
1. Standard consistency (p) is determined using the Vicat apparatus to find the water percentage required to produce a standard cement paste. 2. For testing the setting time of cement, the test paste is prepared with a specific fraction of standard consistency. 3. The required water content for the initial setting time test is 0.85 times p (0.85 p). Answer: B
Explanation
Standard testing procedures specify using 85 percent of the water required for standard consistency (0.85 p) when preparing a cement paste to test setting times. This controlled proportion ensures consistent paste viscosity so that the penetration of the Vicat needle accurately measures the setting process.
Why the other options are wrong
A) A water content of 0.65 p is used for conducting the soundness test of cement using Le-Chatelier's apparatus. C) A water content of 0.6 p is lower than the standard required proportion for setting time tests. D) A water content of 0.78 p is used for testing the tensile strength of cement.
Shortcut
Initial setting time test uses 0.85p water content.
Common mistake
Confusing the water ratio factor for initial setting time (0.85p) with the soundness test factor (0.78p).
Correct answer: B) 0.85 p