GB/T 50082-2009 English PDF (GB/T50082-2009)

GB/T 50082-2009: Standard for test methods of long-term performance and durability of ordinary concrete
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GB/T 50082-2009
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
UDC
P GB/T 50082-2009
Standard for test methods of long-term performance and
durability of ordinary concrete
ISSUED ON: NOVEMBER 30, 2009
IMPLEMENTED ON: JULY 01, 2010
Issued by: Ministry of Housing and Urban-Rural Development of PRC.
General Administration of Quality Supervision, Inspection and
Quarantine of PRC.
Table of Contents
Foreword ... 5
1 General provisions ... 8
2 Terms ... 8
3 Basic requirements ... 9
3.1 Sampling ... 9
3.2 Section size of specimen ... 9
3.3 Tolerances of specimen ... 9
3.4 Preparation and curing of specimen ... 10
3.5 Test report ... 10
4 Test methods for resistance of concrete to freezing and thawing ... 11
4.1 Test method for slow freezing and thawing ... 11
4.2 Test method for rapid freezing and thawing ... 16
4.3 Test method for single-side freezing and thawing ... 20
5 Test method for dynamic modulus of elasticity ... 32
6 Test methods for resistance of concrete to water penetration ... 34
6.1 Test method for depth of water penetration ... 34
6.2 Test method for gradual pressure loading ... 38
7 Test methods for resistance of concrete to chloride penetration ... 38
7.1 Test method for rapid chloride ions migration coefficient (or RCM method) ... 39
7.2 Test method for Coulomb electric flux ... 46
8 Test methods for shrinkage of concrete ... 51
8.1 Non-contact method ... 51
8.2 Contact method ... 53
9 Test method for early cracking of concrete... 57
10 Test method for creep of concrete in compression ... 60
11 Test method for carbonization of concrete ... 66
12 Test method for corrosion of embedded steel reinforcement in concrete ... 69
13 Test method for fatigue deformation of concrete in compression ... 71
14 Test method for resistance of concrete to sulphate attack ... 73
15 Test method for alkali-aggregate reaction... 77
Explanation of wording in this standard ... 81
List of quoted standards ... 82
Standard for test methods of long-term performance and
durability of ordinary concrete
1 General provisions
1.0.1 This standard is formulated in order to standardize and unify the long-term
performance and durability test methods of concrete and improve the concrete test and
detection level.
1.0.2 This standard is applicable to long-term performance and durability testing of
ordinary concrete during engineering construction activities.
1.0.3 This standard specifies the basic technical requirements for long-term
performance and durability testing of ordinary concrete. When this standard conflicts
with the provisions of national laws and administrative regulations, the provisions of
national laws and administrative regulations shall be implemented.
1.0.4 In addition to complying with the provisions of this standard, the long-term
performance and durability tests of ordinary concrete shall also comply with the
provisions of the current national standards.
2 Terms
2.0.1 Ordinary concrete
Cement concrete, which has a dry apparent density of (2000 ~ 2800) kg/m3.
2.0.2 Resistance grade to freezing-thawing of concrete
The freezing resistance class of concrete, which is divided by the maximum number of
freeze-thaw cycles, as measured by the slow freezing method.
2.0.3 Resistance class to freezing-thawing of concrete
The freezing resistance class of concrete, which is divided by the maximum number of
freeze-thaw cycles, as measured by the quick freezing method.
2.0.4 Test method for coulomb electric flux
A test method, that uses the electric flux passing through a concrete specimen to reflect
the resistance of concrete to chloride ion penetration.
exceed the side length or 0.0005 of diameter of the specimen.
3.3.2 Except for the water penetration resistant specimen, the angle between adjacent
faces of all other specimens shall be 90°; the tolerance shall not exceed 0.5°.
3.3.3 Except for the dimensional tolerances of specially specified specimens, the
tolerance of each side length, diameter or height of all specimens shall not exceed 1
mm.
3.4 Preparation and curing of specimen
3.4.1 The preparation and curing of specimens shall comply with the provisions of the
current national standard "Standard for test method of mechanical properties on
ordinary concrete" GB/T 50081.
3.4.2 When preparing specimens for long-term performance and durability tests of
concrete, hydrophobic release agents shall not be used.
3.4.3 When preparing specimens for long-term performance and durability tests of
concrete, it should simultaneously prepare specimens for concrete cube compressive
strength corresponding to the durability performance test age.
3.4.4 When preparing specimens for long-term performance and durability tests of
concrete, the vibration table and mixer used shall comply with the current industry
standards "Vibrating table for concrete test" JG/T 245 and "Mixers for concrete test"
JG 244, respectively.
3.5 Test report
3.5.1 The content provided by the entrusting organization shall include the following
items:
1 Name of the entrusting organization and witnessing organization.
2 Project name and construction location.
3 Name of the item required to be tested.
4 Other things to note.
3.5.2 The content provided by the specimen preparation organization shall include the
following items:
1 Specimen number.
2 Date of specimen preparation.
3 Concrete strength grade.
4 Shape and size of specimen.
5 Types, specifications, origin of raw materials, as well as concrete mix proportions.
6 Curing conditions.
7 Test ages.
8 Other things to note.
3.5.3 The content provided by the testing or inspection organization shall include the
following items:
1 Date the specimen is received.
2 The shape and size of the specimen.
3 Test number.
4 Test date.
5 Name, model, serial number of the instrument and equipment.
6 Test chamber temperature (humidity).
7 Curing conditions and test age.
8 Actual strength of concrete.
9 Test results.
10 Other things to note.
4 Test methods for resistance of concrete to freezing and
thawing
4.1 Test method for slow freezing and thawing
4.1.1 This method is suitable for determining the frost resistance of concrete specimens,
which is expressed in terms of the number of freeze-thaw cycles they have endured,
under air-freezing and water-thawing conditions.
4.1.2 The specimens used in the freezing resistance test, by slow freezing method, shall
meet the following requirements:
20 ~ 20) °C; the measurement accuracy shall be ±0.5 °C.
4.1.4 The slow freezing test shall be carried out according to the following steps:
1 The specimens of the freeze-thaw test, which are cured in the standard curing
chamber or under the same conditions, shall be taken out from the curing location
in advance, when the curing age is 24 days. Then the specimens shall be soaked in
(20 ± 2) °C water. The water level shall be (20 ~ 30) mm higher than the top surface
of the specimen, during immersion. The immersion time in water shall be 4 days.
The freeze-thaw test shall be started, when the specimen reaches 28-day age. For
freeze-thaw specimens that are always cured in water, when the curing age of the
specimen reaches 28 days, subsequent tests can be directly conducted. This
situation shall be explained in the test report.
2 When the curing age of the specimen reaches 28 days, it shall take out the specimen
for the freeze-thaw test in time; use a damp cloth to wipe off the surface moisture,
to measure the appearance dimensions. The appearance dimensions of the
specimen shall meet the requirements of Clause 3.3 of this standard. They shall be
numbered and weighed respectively, then placed into the specimen rack according
to the number. The contact area between the specimen rack and the specimen
should not exceed 1/5 of the bottom surface of the specimen. There shall be a gap
of at least 20 mm between the specimen and the inner wall of the box. A gap of at
least 30 mm shall be maintained between each specimen in the specimen rack.
3 The freezing time shall be calculated, when the temperature in the freeze-thaw box
drops to -18 °C. The time required from the time the specimen is installed until the
temperature drops to -18 °C shall be within (1.5 ~ 2.0) h. The temperature inside
the freeze-thaw box shall be maintained at (-20 ~ -18) °C during freezing.
4 The freezing time of the specimen in each freeze-thaw cycle shall not be less than
4 hours.
5 After freezing, it shall add water at a temperature of (18 ~ 20) °C immediately, to
transfer the specimen to a thawing state. The time for adding water shall not exceed
10 minutes. The control system shall ensure that the water temperature is not lower
than 10 °C within 30 minutes, meanwhile the water temperature can be maintained
at (18 ~ 20) °C after 30 minutes. The water level in the freeze-thaw box shall be at
least 20 mm higher than the surface of the specimen. The thawing time shall not be
less than 4 h. The completion of thawing is considered as the end of the freeze-
thaw cycle; then it can enter the next freeze-thaw cycle.
6 It should perform a visual inspection on the freeze-thaw specimen once every 25
cycles. When serious damage occurs, weighing shall be carried out immediately.
When the average mass loss rate of a group of specimens exceeds 5%, it may stop
the freeze-thaw cycle test.
7 After the specimen reaches the number of freeze-thaw cycles specified in Table
4.1.2 of this standard, the specimen shall be weighed and visually inspected; it shall
carefully record the surface damage, cracks, corner defects of the specimen in detail.
When the surface of the specimen is seriously damaged, it shall be leveled with
high-strength gypsum first; then the compressive strength test shall be carried out.
The compressive strength test shall comply with the relevant provisions of the
current national standard "Standard for test method of mechanical properties on
ordinary concrete" GB/T 50081.
8 When the freeze-thaw cycle is interrupted for some reason and the specimen is in
a frozen state, the specimen shall continue to remain frozen, until the freeze-thaw
test is resumed. The cause of the failure and the suspension time shall be noted in
the test results. When the specimen is interrupted for any reason while it is in a
thawing state, the interruption time shall not exceed the time of two freeze-thaw
cycles. During the entire test, the number of interruption failures which have a
duration exceeding two freeze-thaw cycles shall not exceed two.
9 When some specimens are taken out due to failure or discontinuation of testing,
blank specimens shall be used to fill the gaps.
10 The control specimens shall continue to maintain the original curing conditions,
until the freeze-thaw cycle is completed. The compressive strength test shall be
conducted at the same time as the freeze-thaw specimens.
4.1.5 When one of the following three conditions occurs during the freeze-thaw cycle,
it may stop the test:
1 The specified number of cycles that has been reached;
2 The compressive strength loss rate has reached 25%;
3 The mass loss rate has reached 5%.
4.1.6 The calculation and processing of test results shall comply with the following
provisions:
1 The strength loss rate shall be calculated according to the following formula:
Where:
Δfc - Compressive strength loss rate of concrete (%) after N freeze-thaw cycles,
accurate to 0.1;
operation, the temperature difference of each point of the antifreeze liquid in the
freeze-thaw box shall not exceed 2 °C.
3 The maximum range of the weighing equipment shall be 20 kg. The sensitivity
shall not exceed 5 g.
4 The measuring instrument for concrete dynamic elastic modulus shall comply with
the provisions of Chapter 5 of this standard.
5 Temperature sensors (including thermocouples, potentiometers, etc.) shall measure
the center temperature of the specimen within the range of (-20 ~ 20) °C; the
measurement accuracy shall be ±0.5 °C.
4.2.3 The specimens used in the anti-freeze test by quick-freezing method shall meet
the following requirements:
1 The freezing resistance test of the quick freezing method shall use prism specimens,
which have dimensions of 100 mm × 100 mm × 400 mm. Each group of specimens
shall consist of 3 pieces.
2 When molding specimens, hydrophobic release agents shall not be used.
3 In addition to making the specimens for the freeze-thaw test, a temperature
measurement specimen of the same shape and size shall be made, which has a
temperature sensor buried in the center. The temperature measurement specimen
shall use antifreeze as the freezing-thawing medium. The freezing resistance of the
concrete, which is used in the temperature measurement specimens, shall be higher
than that of the freeze-thaw specimens. The temperature sensor of the temperature
measurement specimen shall be buried in the center of the specimen. Temperature
sensors shall not be buried by drilling and then inserting.
4.2.4 The quick freezing test shall be carried out according to the following steps:
1 Specimens for freezing-thawing test, which is cured in a standard curing chamber
or under the same conditions, shall be taken out from the curing location, before
the curing age reaches 24 days. Then the frozen-thaw specimens shall be soaked in
(20 ± 2) °C water. The water level shall be (20 ~ 30) mm higher than the top surface
of the specimen during immersion. The immersion time in water shall be 4 days.
The freeze-thaw test shall be started when the specimen reaches 28-day age. For
specimens that are always cured in water, when the curing age of the specimen
reaches 28 days, subsequent tests can be conducted directly. This situation shall be
stated in the test report.
2 When the curing age of the specimen reaches 28 days, it shall take out the specimen
in time. Use a damp cloth, to wipe off the surface moisture, before measuring the
appearance size. The app...