---
title: "Maturity of concrete"
subject: "Concrete Technology and Masonry Structure"
chapter: 4
key: "semester_5/concrete_technology_and_masonry_structure:maturity-of-concrete"
source: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/maturity-of-concrete
site: BCT Engineering
---

# Maturity of concrete

Concrete Technology and Masonry Structure · Chapter 4: Properties of hardened concrete

- Asked in: 2074 Chaitra, 4 marks
- Video: [Concrete Maturity | Concept and Application](https://www.youtube.com/watch?v=XTtNN8Ikfe4) — Giatec Scientific Inc.
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/maturity-of-concrete
- Whole chapter: https://www.bctengineer.com/md/semester_5/concrete_technology_and_masonry_structure/chapter-4

## Question

Explain the maturity of concrete with suitable example.

## Short answer

Maturity M = Σ(T - T0)Δt, with datum T0 ≈ -10.5°C; same maturity gives similar strength. Example: 20°C for 28 days gives M = (20+10)×28×24 = 20160°C-h. Reaching that maturity at 10°C takes 42 days, at 30°C takes 21 days.

## Answer

**Maturity of concrete** is the product of curing time and temperature above a datum temperature. It lets the strength of concrete cured at different temperatures be compared, since strength is a function of maturity (Saul's rule).

$$
M = \sum (T - T_0)\,\Delta t
$$

where $T$ = mean temperature of concrete during the interval $\Delta t$ (°C), $T_0$ = datum temperature (about $-10.5$ °C as per Saul; $-11$ °C is often used), and the unit of $M$ is °C-hours (or °C-days).

Concrete of the same mix that has the same maturity has about the same strength, whatever its temperature history.

**Example.** Concrete cured at 20 °C for 28 days has maturity $= (20+10)\times 28\times 24 = 20160$ °C-h. Concrete cured at 10 °C reaches the same maturity in $20160/((10+10)\times 24)= 42$ days. Concrete at 30 °C needs only $20160/((30+10)\times 24) = 21$ days.

**Use:** estimating in-situ strength to decide stripping time, hot/cold weather planning and steam-cured precast products. The rule works well only for the early age and when the concrete is not dried out.

## Check yourself

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

1. Maturity of concrete is:
   A. the sum of (temperature above datum) x time, used to compare strength of concrete cured at different temperatures
   B. the age of concrete in days from casting
   C. the ratio of 28-day strength to 7-day strength
   D. the degree of hydration measured by UPV
   Answer: A. M = sum (T - T0) delta t; same mix with same maturity has about the same strength. (Key point: Maturity concept)

2. In Saul's maturity expression the datum temperature T0 is about:
   A. +10.5 C
   B. -10.5 C
   C. 0 C only
   D. 28 C
   Answer: B. Hydration continues slightly below 0 C so T0 is taken as about -10.5 C. (Key point: Datum temperature)

3. Concrete cured at 20 C for 28 days has maturity 20160 C-h (datum -10 C). Time for the same maturity at 10 C is:
   A. 56 days
   B. 14 days
   C. 42 days
   D. 28 days
   Answer: C. 20160/((10+10)x24) = 42 days; lower temperature needs longer time for the same maturity. (Key point: Maturity example)

4. The maturity rule works well only:
   A. at any age whatever the moisture
   B. for different mixes
   C. only for steam-cured units
   D. at early age and when concrete is not dried out
   Answer: D. Drying stops hydration so the rule fails. (Key point: Limit of rule)

## Related in Concrete Technology and Masonry Structure

- [Maturity; shrinkage and creep](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Amaturity-shrinkage-creep) — Concrete Technology and Masonry Structure, chapter 4