The Maturity MethodPredicting Early Age Strength of Concrete

© Giatec Scientific Inc., 2015

Early Age Strength Challenge !

SpeedSafety

Construction Sequence

Formwork Removal

Casting Next Floor !

The Tail of Two “T”s

TemperatureTime

Combined effect of Time and Temperature

0 5 10 15 20 25 300

2

4

6

8

10

12

14

16

Age

Com

pres

sive

Stre

ngth

0 10 20 30 40 50 6018

19.5

21

22.5

24

25.5

27

28.5

30

Age

Tem

pera

ture

Nurse, R.W., Steam curing of concrete, Mag. Concr. Res., 1(2), 79, 1949.

Maturity Functions: Nurse-Saul

0 10 20 30 40 50 6018

21

24

27

30

Age

Tem

pera

ture

T0

t

Datum Temperature

𝑀 (𝑡 )=∑ (𝑇 −𝑇0 ) . ∆𝑡

Saul, A.G.A., Principles underlying the steam curing of concrete at atmospheric pressure, Mag. Concr. Res., 2(6), 127, 1951.

Maturity Functions: Equivalent Age

0 2 4 6 8 10 12 14 16 18 20 22 24 26 280

3

6

9

12

15

Equivalent age at Tr

Stre

ngth

𝑡𝑒=∑ (𝑇 −𝑇 0 )

(𝑇𝑟 −𝑇 0 )∆𝑡

Based on Linear Relationship

𝑡𝑒=∑0

𝑡

𝑒−𝑄 ( 1𝑇 − 1𝑇 𝑟 )∆𝑡

Based on Arrhenius Equation

: Reference TemperatureQ: Activation Energy

Strength – Maturity Relationships

1

37

1428

0 5 10 15 20 25 300

2

4

6

8

10

12

14

16

Age

Com

pres

sive

Stre

ngth

Samples should be cured in water bath or in the moist room.

Strength – Maturity Relationships

0 10 20 30 40 50 6018

19.5

21

22.5

24

25.5

27

28.5

30

Age

Tem

pera

ture

Strength – Maturity Relationships

0 7 14 21 280

5

10

15

Age

Com

pres

sive

Stre

ngth

0 20 40 600

200400600800

100012001400160018002000

Age

Mat

urity

Inde

x

2 3 4 50

10

20

30

f(x) = 10.902149510791 x − 23.329011002221

Log (Maturity Index)

Com

pres

sive

Stre

ngth

Standards and GuidelinesASTM C 1074

The Standard test procedure to Maturity Method

Building Codes ACI 318: 6-2: Removal of forms, shores, and reshoring CSA A23.2.14C / A23.2-15: Removal of shores and forms

Test has been adapted by several DOTs across the North America

A new Approach to Maturity Measurement

“SmartRock™ wireless concrete sensor”

Limitations

Strength of In-place Concrete Lab cured Samples

High Early-Age Temperatures

Datum Temperature

Field Practice

Field Practice

Field Practice

Field Practice

Age

Tem

pera

ture

Age

Mat

urity

Inde

x

Field Practice

Age

Tem

pera

ture

Age

Mat

urity

Inde

x

Maturity IndexC

ompr

essi

ve S

treng

th

𝒇 𝒄′ =𝑎+𝑏 . log (𝑀 )

R&D Department | Giatec Scientific Inc.301 Moodie Dr., Suite 302Ottawa, ON, K2H 9C4 Canada

Tel: (613) 240 – 7451Email: support@giatecscientific.com

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