---
title: "Curing of concrete"
subject: "Concrete Technology and Masonry Structure"
chapter: 3
key: "semester_5/concrete_technology_and_masonry_structure:curing-of-concrete"
source: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/curing-of-concrete
site: BCT Engineering
---

# Curing of concrete

Concrete Technology and Masonry Structure · Chapter 3: Mix design of concrete and property of green concrete

- Asked in: 2065 Shrawan (old course), 2 marks
- Video: [Why Curing of Concrete is Important? Concrete Curing Process](https://www.youtube.com/watch?v=APpTjxgVhx8) — Civil Mentors
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/curing-of-concrete
- Whole chapter: https://www.bctengineer.com/md/semester_5/concrete_technology_and_masonry_structure/chapter-3

## Question

Write a short note on curing of concrete.

## Short answer

Curing is maintaining moisture and temperature in fresh concrete to ensure proper hydration, preventing 30-50% strength loss. Methods include ponding, wet coverings, spraying, membrane compounds, and steam curing. For ordinary Portland cement, cure for at least 7 days; at least 10 days with mineral admixtures or hot/dry weather, and 14 days recommended for blended cement.

## Answer

**Curing** is the process of keeping freshly placed concrete moist and at a suitable temperature for a period, so that cement hydration continues and the concrete gains strength and durability. Without curing the surface dries, hydration stops, and strength can be 30 to 50% lower with more shrinkage cracks and permeability.

**Methods:** ponding or immersion; covering with wet hessian, sand or straw and sprinkling; spraying water; membrane curing compounds and polythene sheets; steam curing for precast units.

**Period (IS 456, Cl. 13.5.1):** keep exposed surfaces continuously damp for at least 7 days for ordinary Portland cement and at least 10 days where mineral admixtures or blended cements are used. In dry and hot weather the period must not be less than 10 days; for blended cements it is recommended to extend it to 14 days. Formwork is removed only after the minimum striking period (IS 456, Cl. 11.3).

## Check yourself

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

1. Curing is:
   A. compacting concrete with vibrators
   B. keeping fresh concrete moist and at a suitable temperature so hydration continues
   C. mixing the ingredients thoroughly
   D. testing cubes at 28 days
   Answer: B. Curing maintains moisture and temperature for continued hydration. (Key point: Definition of curing)

2. Without curing the concrete will:
   A. gain extra strength from fast drying
   B. become less permeable
   C. dry at the surface, stop hydrating, and lose 30 to 50% strength with more cracking
   D. reach full strength in 7 days
   Answer: C. Drying halts hydration, lowering strength and raising shrinkage cracks and permeability. (Key point: Effect of no curing)

3. IS 456 minimum damp curing for OPC is:
   A. 7 days (10 days with blended cements or in hot dry weather)
   B. 1 day
   C. 3 days
   D. 28 days
   Answer: A. OPC needs at least 7 days; mineral admixtures or hot, dry weather need at least 10 days. (Key point: Curing period)

## Related in Concrete Technology and Masonry Structure

- [Hot climate concreting and curing](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Ahot-weather-methods-curing) — Concrete Technology and Masonry Structure, chapter 3
- [Casting and curing temperature; concreting in Kathmandu](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Acasting-curing-temperature-kathmandu) — Concrete Technology and Masonry Structure, chapter 4