---
title: "Setting time significance and test"
subject: "Civil Engineering Materials"
chapter: 5
key: "semester_3/civil_engineering_materials:setting-time-significance-test"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/setting-time-significance-test
site: BCT Engineering
---

# Setting time significance and test

Civil Engineering Materials · Chapter 5: Cement

- Asked in: 2068 Chaitra, 2+2 marks
- Video: [Initial and Final setting time of Cement by Dr. Aruna Rawat | Civil Engineering | RGPV](https://www.youtube.com/watch?v=qOsJE5ffgJc) — RGPV Official
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/setting-time-significance-test
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-5

## Question

Explain the significance of testing the initial and final setting time of cement. How is it done?

## Short answer

Initial time ensures adequate working period for mixing, transporting, placing; final time indicates hardening for load bearing. Vicat test: mix paste at 0.85P consistency; initial setting when 1 mm needle penetrates to 5±0.5 mm from bottom; final when annular collar only leaves needle impression. Time from water addition, 27±2°C, 90% humidity.

## Answer

#### Significance
- The initial setting time gives enough time to mix, transport, place and compact the concrete or mortar before it stiffens; a short value (less than 30 min) makes the work difficult.
- The final setting time shows when the concrete has hardened enough to bear loads, which helps decide when formwork can be removed, curing started and the work moved on.
- It checks quality: abnormal setting (flash set or false set) indicates deterioration, wrong gypsum content or storage defects.
- It shows whether the cement suits the work (for example, hot-weather work).

#### Test (Vicat apparatus, IS 4031 Part 5)
1. Take 400 g of cement and mix it with water equal to **0.85 P** (P is the standard consistency percentage); gauge for 3-5 minutes, starting the stopwatch at the moment water is added.
2. Fill the Vicat mould resting on a glass plate and level the top.
3. **Initial setting time:** lower the 1 mm square needle gently onto the paste at regular intervals. When the needle stops 5 ± 0.5 mm from the bottom of the mould, the time elapsed since adding water is the initial setting time.
4. **Final setting time:** replace the needle with the needle having the annular collar (attachment). Final setting is reached when the needle makes an impression but the collar does not. The time is counted from adding water.
5. Keep the apparatus at 27 ± 2 C and 90% humidity, and do not let the needle fall on the same spot twice.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Why is the initial setting time important?
   A. It tells the 28-day strength
   B. It measures fineness
   C. It gives soundness
   D. It allows time to mix, transport, place and compact before stiffening
   Answer: D. Too short a time makes work difficult. (Key point: Initial setting significance)

2. What does final setting time decide?
   A. Formwork removal and curing start
   B. Mix ratio
   C. Colour
   D. Specific gravity
   Answer: A. It shows when concrete can bear loads. (Key point: Final setting significance)

3. Water used in the setting time test:
   A. 0.78 P
   B. 0.85 P
   C. P/4 + 3
   D. 26% fixed
   Answer: B. 400 g cement is mixed with 0.85 times standard consistency water. (Key point: Test water)

4. Which is correct when testing?
   A. Always drop it on the same spot
   B. Test at 50 C
   C. Do not let the needle fall on the same spot twice
   D. Use a 10 mm plunger
   Answer: C. Keep 27 +/- 2 C and 90% humidity and use a new spot. (Key point: Test technique)

## Related in Civil Engineering Materials

- [Define initial and final setting time](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Ainitial-final-setting-time-define) — Civil Engineering Materials, chapter 5
- [Soundness test of cement and procedure](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-soundness-test-procedure) — Civil Engineering Materials, chapter 5
- [Consistency test of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-consistency-test) — Civil Engineering Materials, chapter 5
- [Why soundness test of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Awhy-soundness-test-cement) — Civil Engineering Materials, chapter 5

## Related in other subjects

- [Setting, setting time, admixture vs additive](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Asetting-time-admixture-additive-diff) — Concrete Technology and Masonry Structure, chapter 1
- [Setting versus hardening of cement](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Asetting-vs-hardening) — Concrete Technology and Masonry Structure, chapter 1
- [Field testing of cement quality](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Acement-field-tests) — Concrete Technology and Masonry Structure, chapter 1, asked 2×
- [Testing of DC machines: retardation vs Swinburne's test](https://www.bctengineer.com/question.md?key=semester_4%2Felectrical_machines_i%3Adc-testing-retardation-vs-swinburne) — Electrical Machines I, chapter 4