ASTM C1074-98

Standard Practice for Estimating Concrete Strength by the Maturity Method

SCOPE
1.1 This practice provides a procedure for estimating concrete strength by means of the maturity method. The maturity index is expressed either in terms of the temperature-time factor or in terms of the equivalent age at a specified temperature.  
1.2 This practice requires establishing the strength-maturity relationship of the concrete mixture in the laboratory and recording the temperature history of the concrete for which strength is to be estimated.  
1.3 The values stated in SI units are to be regarded as the standard.  
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Nov-1998
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.64 - Nondestructive and In-Place Testing

Relations

• Replaced By: ASTM C1074-04 - Standard Practice for Estimating Concrete Strength by the Maturity Method
• Effective Date: 01-Jun-2004
• Referred By: ASTM C918/C918M-20 - Standard Test Method for Measuring Early-Age Compressive Strength and Projecting Later-Age Strength
• Effective Date: 10-Nov-1998
• Referred By: ASTM C125-21a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 10-Nov-1998

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C 1074 – 98
Standard Practice for
Estimating Concrete Strength
by the Maturity Method
This standard is issued under the fixed designation C 1074; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope Testing of Concrete Compression Test Specimens
C 803/C 803M Test Method for Penetration Resistance of
1.1 This practice provides a procedure for estimating con-
Hardened Concrete
crete strength by means of the maturity method. The maturity
C 873 Test Method for Compressive Strength of Concrete
index is expressed either in terms of the temperature-time
Cylinders Cast in Place in Cylindrical Molds
factor or in terms of the equivalent age at a specified tempera-
C 900 Test Method for Pullout Strength of Hardened Con-
ture.
crete
1.2 This practice requires establishing the strength-maturity
C 918 Test Method for Measuring Early-Age Compressive
relationship of the concrete mixture in the laboratory and
Strength and Projecting Later-Age Strength
recording the temperature history of the concrete for which
C 1150 Test Method for the Break-Off Number of Con-
strength is to be estimated.
crete
1.3 The values stated in SI units are to be regarded as the
standard.
3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.1.1 datum temperature—the temperature that is subtracted
responsibility of the user of this standard to establish appro-
from the measured concrete temperature for calculating the
priate safety and health practices and determine the applica-
temperature-time factor according to Eq 1.
bility of regulatory limitations prior to use.
3.1.2 equivalent age—the number of days or hours at a
2. Referenced Documents specified temperature required to produce a maturity equal to
the maturity achieved by a curing period at temperatures
2.1 ASTM Standards:
different from the specified temperature.
C 39 Test Method for Compressive Strength of Cylindrical
2 3.1.3 maturity—the extent of the development of a property
Concrete Specimens
of a cementitious mixture.
C 109/C 109M Test Method for Compressive Strength of
3.1.3.1 Discussion—While the term is used usually to
Hydraulic Cement Mortars (Using 2-in. or 50-mm Cube
describe the extent of relative strength development, it can also
Specimens)
be applied to the evolution of other properties that are
C 192/C 192M Practice for Making and Curing Concrete
dependent on the chemical reactions that occur in a cementi-
Test Specimens in the Laboratory
tious mixture. At any age, maturity is dependent on the curing
C 403/C 403M Test Method for Time of Setting of Concrete
history.
Mixtures by Penetration Resistance
3.1.4 maturity function—a mathematical expression that
C 511 Specification for Moist Cabinets, Moist Rooms, and
uses the measured temperature history of a cementitious
Water Storage Tanks Used in the Testing of Hydraulic
mixture during the curing period to calculate an index that is
Cements and Concretes
indicative of the maturity at the end of that period. Refer to
C 684 Test Method for Making, Accelerated Curing, and
Appendix X1 for additional discussion of this term.
3.1.5 maturity index—an indicator of maturity that is calcu-
lated from the temperature history of the cementitious mixture
This practice is under the jurisdiction of ASTM Committee C-9 on Concrete
by using a maturity function.
and Concrete Aggregates and is the direct responsibility of Subcommittee C09.64 on
Nondestructive and In-Place Testing.
3.1.5.1 Discussion—The computed index is indicative of
Current edition approved Nov. 10, 1998. Published March 1999. Originally
maturity provided there has been a sufficient supply of water
e1
published as C 1074 – 87. Last previous edition C 1074 – 93 .
for hydration or pozzolanic reaction of the cementitious
Annual Book of ASTM Standards, Vol 04.02.
Annual Book of ASTM Standards, Vol 04.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C1074–98
materials during the time used in the calculation. Two widely
M(t) = the temperature-time factor at age t, degree-days or
used maturity indexes are the temperature-time factor and the
degree-hours,
equivalent age.
Dt = a time interval, days or hours,
3.1.6 maturity method—a technique for estimating concrete T = average concrete temperature during time interval,
a
strength that is based on the assumption that samples of a given
Dt, °C, and
T = datum temperature, °C.
concrete mixture attain equal strengths if they attain equal
o
values of the maturity index (1, 2, 3). 6.3 The other maturity function is used to compute equiva-
3.1.7 strength-maturity relationship—an empirical relation- lent age at a specified temperature as follows (4):
ship between compressive strength and maturity index that is
1 1
2Q 2
S D
T T
t 5 (e D t (2)
a s
obtained by testing specimens whose temperature history up to e
the time of test has been recorded.
where:
3.1.8 temperature-time factor—the maturity index com-
t = equivalent age at a specified temperature T , days or
e s
puted according to Eq 1.
h,
Q = activation energy divided by the gas constant, K,
4. Summary of Practice
T = average temperature of concrete during time interval
a
4.1 A strength-maturity relationship is developed by labo-
Dt,K,
ratory tests on the concrete mixture to be used.
T = specified temperature, K, and
s
4.2 The temperature history of the field concrete, for which
Dt = time interval, days or h.
strength is to be estimated, is recorded from the time of
6.4 Approximate values of the datum temperature, T , and
o
concrete placement to the time when the strength estimation is
the activation energy divided by the gas constant, Q, are given
desired.
in Appendix X1. Where maximum accuracy of strength esti-
4.3 The recorded temperature history is used to calculate the
mation is desired, the appropriate values of T or Q for a
o
maturity index of the field concrete.
specific concrete mixture can be determined according to the
4.4 Using the calculated maturity index and the strength-
procedures given in Annex A1.
maturity relationship, the strength of the field concrete is
estimated.
7. Apparatus
7.1 A device is required to monitor and record the concrete
5. Significance and Use
temperature as a function of time. Acceptable devices include
5.1 This practice can be used to estimate the in-place
thermocouples or thermistors connected to strip-chart recorders
strength of concrete to allow the start of critical construction
or digital data-loggers. The recording time interval shall be ⁄2
activities such as: (1) removal of formwork and reshoring; (2)
h or less for the first 48 h and1hor less thereafter. The
post-tensioning of tendons; (3) termination of cold weather
temperature recording device shall be accurate to within 61°C.
protection; and (4) opening of the roadways to traffic.
7.2 Alternative devices include commercial maturity instru-
5.2 This practice can be used to estimate strength of
ments, that automatically compute and display either
laboratory specimens cured under non-standard temperature
temperature-time factor or equivalent age.
conditions.
5.3 The major limitations of the maturity method are: (1) the NOTE 1—Commercial maturity instruments use specific values of
datum temperature or activation energy in evaluating the maturity index;
concrete must be maintained in a condition that permits cement
thus the displayed maturity index may not be indicative of the true value
hydration; (2) the method does not take into account the effects
for the concrete mixture being used. Refer to Appendix X1 for information
of early-age concrete temperature on the long-term ultimate
on correcting the displayed values.
strength; and (3) the method needs to be supplemented by other
indications of the potential strength of the concrete mixture.
8. Procedure to Develop Strength-Maturity Relationship
5.4 The accuracy of the estimated strength depends on
8.1 Prepare at least 15 cylindrical specimens according to
properly determining the maturity function for the particular
Practice C 192/C 192M . The mixture proportions and con-
concrete mixture.
stituents of the concrete shall be similar to those of the concrete
whose strength will be estimated using this practice.
6. Maturity Functions
8.2 Embed temperature sensors to within 615 mm of the
6.1 There are two alternative functions for computing the
centers of at least two specimens. Connect the sensors to
maturity index from the measured temperature history of the
maturity instruments or to temperature-recording devices such
concrete.
as data-loggers or strip-chart recorders.
6.2 One maturity function is used to compute the
temperature-time factor as follows:
NOTE 2—A method to assist in the proper positioning of the sensor is to
insert a small diameter rigid rod into the center of the freshly made
M t! 5 ( T 2 T ! Dt (1)
~ ~
a o
cylinder. The rod will push aside any interfering aggregate particles. The
rod is removed and the sensor is inserted into the cylinder. The side of the
where:
cylinder mold should be tapped with a rubber mallet or the tamping rod to
ensure that the concrete comes into contact with the sensor.
8.3 Moist cure the specimens in a water bath or in a moist
The boldface numbers in parentheses refer to the list of references at the end of
this practice. room meeting the requirements of Specification C 511.
C1074–98
8.4 Perform compression tests at ages of 1, 3, 7, 14, and 28
days in accordance with Test Method C 39. Test two specimens
at each age and compute the average strength. If the range of
compressive strength of the two specimens exceeds 10 % of
their average strength, test another cylinder and compute the
average of the three tests. If a low test result is due to an
obviously defective specimen, discard the low test result.
8.5 At each test age, record the average maturity index for
the instrumented specimens.
8.5.1 If maturity instruments are used, record the average of
the displayed values.
8.5.2 If temperature recorders are used, evaluate the matu-
rity according to Eq 1 or Eq 2. Use a time interval (Dt)of ⁄2
h or less for the first 48 h of the temperature record. Longer
time intervals may be used for the relatively constant portion of
the subsequent temperature record.
FIG. 2 Example of a Relationship Between Compressive Strength
NOTE 3—Appendix X2 gives an example of how to evaluate the
and Equivalent Age at 20°C
temperature-time factor or equivalent age from the recorded temperature
history of the concrete.
NOTE 5—In building construction, exposed portions of slabs and
8.6 On graph paper, plot the average compressive strength
slab-column connections are typically critical locations. The advice of the
as a function of the average value of the maturity index. Draw
Engineer should be sought for the critical locations in the particular
a best-fit curve through the data. The resulting curve is the
structure under construction.
strength-maturity relationship to be used for estimating the
9.2 Connect the sensors to maturity instruments or
strength of the concrete mixture cured under other temperature
temperature-recording devices and activate the recording de-
conditions. Fig. 1 is an example of a relationship between
vices as soon as is practicable.
compressive strength and temperature-time factor, and Fig. 2 is
9.3 When the strength at the location of a sensor is to be
an example of a relationship between compressive strength and
estimated, read the value of the maturity index from the
equivalent age at 20°C.
maturity instrument or evaluate the maturity index from the
NOTE 4—The strength-maturity relationship can also be established by
temperature record.
using regression analysis to determine a best-fit equation to the data.
9.4 Using the strength-maturity relationship developed in
Possible equations that have been found to be suitable for this purpose
Section 8, read off the value of compressive strength corre-
may be found in Ref. (3).
sponding to the measured maturity index.
9.5 Prior to performing critical operations, such as form-
9. Procedure to Estimate In-Place Strength
work removal or post-tensioning, supplement determination of
9.1 As soon as is practicable after concrete placement,
the concrete maturity with other tests to ensure that the
embed temperature sensors into the fresh concrete. When using
concrete in the structure has a potential strength that is similar
this practice to allow critical construction operations to begin,
to that of the concrete used to develop the strength-maturity
install sensors at locations in the structure that are critical in
relationship. Appropriate techniques include:
terms of exposure conditions and structural requirements.
9.5.1 In-place tests that give indications of strength, such as
Test Method C 803/C 803M, Test Method C 873, Test Method
C 900, or Test Method C 1150.
9.5.2 Early-age compressive strength tests in accordance
with Test Method C 918 of standard-cured specimens molded
from samples of the concrete as-delivered, or
9.5.3 Compressive strength tests on specimens molded from
samples of the concrete as-delivered and subjected to acceler-
ated curing in accordance with Test Method C 684.
10. Precision and Bias
10.1 This practice is used to estimate the in-place strength
of concrete based on the measured thermal history at a point in
the structure and a previously established strength-maturity
relationship. The accuracy of the estimated strength is depen-
dent on several factors, such as the appropriateness of the
maturity function for the specific mixture, the early-age tem-
perature history, and the actual mixture proportions. For this
reason, it is not possible to write statements about the precision
FIG. 1 Example of a Relationship Between Compressive Strength
and Temperature-Time Factor and bias of the estimated strength.
C1074–98
11. Keywords
11.1 maturity method; nondestructive testing; strength;
temperature
ANNEX
(Mandatory Information)
A1. DETERMINATION OF DATUM TEMPERATURE OR ACTIVATION ENERGY
A1.1 Procedure For example, if the time of the first test was 12 h, successive
compressive strength tests would be performed at 1, 2, 4, 8, 16,
A1.1.1 The testing required to experimentally determine the
and 32 days.
datum temperature or the activation energy can b
...