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: [email protected]
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