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GB/T 14902-2012 (GBT14902-2012)

GB/T 14902-2012_English: PDF (GBT 14902-2012, GBT14902-2012)
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GB/T 14902-2012English205 Add to Cart 0--9 seconds. Auto-delivery Ready-mixed concrete Valid GB/T 14902-2012

BASIC DATA
Standard ID GB/T 14902-2012 (GB/T14902-2012)
Description (Translated English) Ready-mixed concrete
Sector / Industry National Standard (Recommended)
Classification of Chinese Standard Q13
Classification of International Standard 91.100.30
Word Count Estimation 15,112
Older Standard (superseded by this standard) GB/T 14902-2003
Quoted Standard GB 175; GB 200; GB/T 1596; GB 8076; GB/T 9142; GB 10171; GB 13693; GB/T 17431.1; GB/T 18046; GB/T 18736; GB/T 20491; GB 23439; GB/T 25176; GB/T 25177; GB/T 50080; GB/T 50081; GB/T 50082; GB/T 50107; GB 50119; GB 50164-2011; GB 50204; GB/T 50557; JC 475; J
Drafting Organization China Academy of Building Research
Administrative Organization National Standardization Technical Committee of concrete
Regulation (derived from) National Standards Bulletin No. 41 of 2012
Issuing agency(ies) General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China
Summary This standard specifies the terms and definitions of ready-mixed concrete, classification, performance levels and markers, and the mix of raw materials, quality requirements, preparation, test methods, inspection rules, orders and deliveries. This standar

Standards related to: GB/T 14902-2012

GB/T 14902-2012
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 91.100.30
Q 13
Replacing GB/T 14902-2003
Ready-mixed Concrete
预拌混凝土
ISSUED ON: DECEMBER 31, 2012
IMPLEMENTED ON: SEPTEMBER 1, 2013
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative References ... 5 
3 Terms and Definitions ... 7 
4 Classification, Performance Grades and Markings ... 8 
5 Raw Materials and Mixing Ratios ... 11 
6 Quality Requirements ... 13 
7 Preparation ... 15 
8 Test Methods ... 18 
9 Inspection Rules ... 19 
10 Ordering and Delivery ... 21 
Ready-mixed Concrete
1 Scope
This Standard specifies the terms and definitions, classification, performance grades
and markings, raw materials and mixing ratios, quality requirements, preparation, test
methods, inspection rules, ordering and delivery of ready-mixed concrete.
This Standard is applicable to ready-mixed concrete produced in mixing plants (towers).
This Standard does not include the pouring, vibrating and curing of concrete after
delivery.
2 Normative References
The following documents are indispensable to the application of this document. In
terms of references with a specified date, only versions with a specified date are
applicable to this document. In terms of references without a specified date, the latest
version (including all the modifications) is applicable to this document.
GB 175 Common Portland Cement
GB 200 Moderate Heat Portland Cement, Low Heat Portland Cement, Low Heat
Portland Slag Cement
GB/T 1596 Fly Ash Used for Cement and Concrete
GB 8076 Concrete Admixtures
GB/T 9142 Concrete Mixers
GB 10171 Concrete Mixing Plant (tower)
GB 13693 Portland Cement for Road
GB/T 17431.1 Lightweight Aggregates and Its Test Methods - Part 1: Lightweight
Aggregates
GB/T 18046 Ground Granulated Blast Furnace Slag Used for Cement and Concrete
GB/T 18736 Mineral Admixtures for High Strength and High Performance Concrete
GB/T 20491 Steel Slag Powder Used for Cement and Concrete
GB 23439 Expansive Agents for Concrete
3 Terms and Definitions
The following terms and definitions are applicable to this document.
3.1 Ready-mixed Concrete
Ready-mixed concrete refers to concrete produced in mixing plants (towers) and
delivered to the place of use by transportation equipment, and in the state of mixtures
at the time of delivery.
3.2 Ordinary Concrete
Ordinary concrete refers to concrete whose dry apparent density is 2,000 kg/m3 ~
2,800 kg/m3.
3.3 High Strength Concrete
High strength concrete refers to concrete whose strength grade is not lower than C60.
3.4 Self-compacting Concrete
Self-compacting concrete refers to concrete that can flow and compact under its own
weight without vibrating.
3.5 Fiber Reinforced Concrete
Fiber reinforced concrete refers to concrete mixed with steel fiber of synthetic fiber as
the reinforcing material.
3.6 Lightweight-aggregate Concrete
Lightweight-aggregate concrete refers to concrete prepared with lightweight coarse
aggregate, light sand or ordinary sand, and with a dry apparent density of not greater
than 1,950 kg/m3.
3.7 Heavy-weight Concrete
Heavy-weight concrete refers to concrete prepared with heavyweight aggregate, for
example, barite, and with a dry apparent density of greater than 2,800 kg/m3.
3.8 Recycled Aggregate Concrete
Recycled aggregate concrete refers to concrete prepared with all or part of recycled
aggregate as the aggregate.
3.9 Delivery Place
Delivery place refers to the place for the delivery of the ready-mixed concrete
4.3 Markings
4.3.1 The markings of the ready-mixed concrete shall comply with the following
sequence:
a) The code of conventional products or special products; conventional products
can be exempted from marking;
b) The type code of special concrete products; when there are multiple types,
they can be simultaneously marked;
c) Strength grade;
d) Slump control target value, followed by the slump grade code in brackets; self-
compacting concrete shall adopt the expansion control target value, followed
by the expansion grade code in brackets;
e) Durability grade code; for the chloride ion penetration resistance and
carbonization resistance, followed by the design value in brackets;
f) Serial No. of this Standard.
4.3.2 Examples of marking
Example 1: ordinary concrete prepared with general-purpose Portland cement, river sand (or
artificial sand or sea sand), stone, mineral admixtures, admixtures and water;
strength grade: C50; slumps: 180 mm; frost resistance grade: F250; electric flux
QS of chloride ion penetration resistance: 1,000 C, shall be marked as:
Example 2: lightweight aggregate fiber reinforced concrete prepared with general-purpose
Portland cement, sand (or ceramic sand), ceramsite, mineral admixtures,
admixtures, synthetic fibers and water; strength grade: LC40; slumps: 210 mm;
penetration resistance grade: P8; frost resistance grade: F150, shall be marked
as:
5 Raw Materials and Mixing Ratios
5.1 Cement
5.1.1 Cement shall comply with the stipulations of GB 175, GB 200 and GB 13693.
5.1.2 The entry of cement shall provide exit-factory inspection reports, for example,
certificate of quality; inspection shall also be carried out. The inspection items and
and inspection batches shall comply with the stipulations of GB 50164.
5.6 Fiber
5.6.1 The steel fiber and synthetic fiber used in concrete shall comply with the
stipulations of JGJ/T 221.
5.6.2 The entry of steel fiber and synthetic fiber shall provide exit-factory inspection
reports, for example, certificate of quality; inspection shall also be carried out. The
inspection items and inspection batches shall comply with the stipulations of JGJ/T
221.
5.7 Mixing Ratios
5.7.1 The design of mixing ratios of ordinary concrete shall be executed by the supply-
side in accordance with the stipulations of JGJ 55; the design of mixing ratios of
lightweight aggregate concrete shall be executed by the supply-side in accordance
with the stipulations of JGJ 51; the design of mixing ratios of fiber reinforced concrete
shall be executed by the supply-side in accordance with the stipulations of JGJ/T 221;
the design of mixing ratios of barite concrete shall be executed by the supply-side in
accordance with the stipulations of GB/T 50557.
5.7.2 The designed mixing ratios shall be adjusted in accordance with the engineering
requirements, then, the construction mixing ratios shall be determined.
6 Quality Requirements
6.1 Strength
The strength of concrete shall satisfy the design requirements. The evaluation of the
inspection shall comply with the stipulations of GB/T 50107.
6.2 Slumps and Slump Loss Through Time
The allowable deviation between the actual measured value of concrete slumps and
the control target value shall comply with the stipulations of Table 8. The slump control
target value of conventional pumping concrete should not be greater than 180 mm,
and shall satisfy the construction requirements; the slump loss through time should not
be greater than 30 mm/h. The slumps of special concrete products shall satisfy the
stipulations of relevant standards and construction requirements.
6.6 Durability
The durability of concrete shall satisfy the design requirements. The evaluation of the
inspection shall comply with the stipulations of JGJ/T 193.
6.7 Other Performances
When the demand-side proposes requirements for other concrete performances, the
tests shall be carried out in accordance with the stipulations of relevant current national
standards. When there are no corresponding standards, the tests shall be carried out
in accordance with the contract. The test results shall satisfy the requirements of the
standards or the contract.
7 Preparation
7.1 General Provisions
7.1.1 The concrete mixing plants (towers) shall comply with the stipulations of GB
10171.
7.1.2 The preparation of the ready-mixed concrete shall include the storage of raw
materials, measurement, mixing and transportation.
7.1.3 The preparation of special products shall comply with the stipulations of this
Chapter. In addition, the barite concrete, the lightweight aggregate concrete and the
fiber reinforced concrete shall also respectively comply with the stipulations of GB/T
50557, JGJ 51 and JGJ/T 221.
7.1.4 The preparation of the ready-mixed concrete shall comply with the stipulations of
environmental protection and should comply with the stipulations of HJ/T 412. The
conveying and weighing of powder shall be carried out in a sealed state, and there
shall be a dust collection device. The machine room of the mixing plant should be a
closed system. Before exiting factory, the concrete residue on the outer wall and
hopper wall of the transport vehicle shall be cleaned. The mixing plant shall collect and
recycle the industrial wastewater and solid waste generated during the production
process.
7.2 Storage of Raw Materials
7.2.1 The various raw materials shall be stored in separate warehouses and shall be
clearly marked.
7.2.2 The cement shall be respectively marked and stored in accordance with the type,
strength grade and manufacturer. In addition, the cement shall be prevented from
damp and contamination. Agglomerated cement shall not be used. When cement is
used for production, its temperature should not be higher than 60 °C. After exiting
7.5.2 Before loading, the mixer truck shall drain the water in the mixing tank. After
loading, it is strictly forbidden to add water to the concrete mixture in the mixing tank.
7.5.3 When admixtures need to be added to the concrete mixture before unloading,
after the admixtures are added, a fast-speed rotary mixing tank shall be adopted for
mixing. There shall be a pre-arranged scheme determined by tests for the amount of
admixtures and the mixing time.
7.5.4 The transportation time of the ready-mixed concrete, starting from the unloading
from the mixer into the mixer truck, to the unloading of materials, should not be greater
than 90 min. If the transportation time needs to be extended, then, corresponding
effective technical measures shall be taken, and verification shall be performed
through tests. When the dump truck is adopted, the transportation time shall not be
greater than 45 min.
8 Test Methods
8.1 Strength
The test method for the strength of concrete shall comply with the stipulations of GB/T
50081.
8.2 Slumps, Expansion Grade, Air Content and Apparent Density
The test method for the slumps, expansion grade, air content and apparent density of
concrete mixtures shall comply with the stipulations of GB/T 50080.
8.3 Slump Loss Through Time
The test method for the slump loss through time of concrete mixtures shall comply with
the stipulations of Appendix A in GB 50164-2011.
8.4 Water-soluble Chloride Ion Content
The water-soluble chloride ion content in concrete mixtures shall be determined in
accordance with the quick determination method for chloride ion content in concrete
mixtures described in JTJ 270, or other methods with a higher accuracy.
8.5 Durability
The test method for the durability of concrete shall comply with the stipulations of GB/T
50082.
8.6 Items of Special Requirements
For other inspection items that are specially required in the contract, the test methods
shall comply with the stipulations of relevant current national standards. If there are no
a) During the inspection at manufacturer, the sampling of concrete with the same
mixing ratio shall not be less than once per 100 plates; when the concrete with
the same mixing ratio in each work shift does not reach 100 plates, it shall be
counted as 100 plates; for each sampling, at least one set of tests shall be
conducted;
b) The sampling frequency of inspection at delivery place shall comply with the
stipulations of GB/T 50107.
9.3.4 The sampling frequency of the slump test of concrete shall be the same as the
strength test.
9.3.5 The inspection of water-soluble chloride ion content in concrete mixtures of the
same mixing ratio shall be sampled at least once. The sampling frequency of the
inspection of water-soluble chloride ion content in sea sand concrete mixtures shall
comply with the stipulations of JGJ 206.
9.3.6 The sampling frequency of the inspection of concrete durability shall comply with
the stipulations of JGJ/T 193.
9.3.7 The sampling frequency of the inspections of air content, expansion grade and
other items of concrete shall comply with the stipulations of relevant current national
standards and the contract.
9.4 Evaluation
9.4.1 When the inspection result of concrete strength complies with the stipulations of
6.1, the concrete shall be determined as qualified.
9.4.2 When the inspection results of slumps, expansion grade and air content of
concrete respectively comply with the stipulations of 6.2, 6.3 and 6.4, the concrete shall
be determined as qualified. When the inspection results do not comply with the
requirements, then, the remaining part of the specimen shall be immediately used, or
re-sampling shall be immediately conducted for re-inspection; when the re-inspection
results respectively comply with the stipulations of 6.2, 6.3 and 6.4, the concrete shall
be determined as qualified.
9.4.3 When the inspection result of water-soluble chloride ion content in concrete
mixture complies with the stipulations of 6.5, the concrete shall be determined as
qualified.
9.4.4 When the inspection result of concrete durability complies with the stipulations of
6.6, the concrete shall be determined as qualified.
9.4.5 When the inspection results of other concrete performances comply with the
stipulations of 6.7, the concrete shall be determined as qualified.
10.3.1 The supply-side shall provide the demand-side with a certificate of inspection
for the concrete of the same mixing ratio in accordance with the sub-project. The
certificate of inspection shall at least include the following contents:
a) Serial No. of certificate of inspection;
b) Serial No. of contract;
c) Name of project;
d) The demand-side;
e) The supply-side;
f) Date of delivery;
g) Location of pouring;
h) Concrete marking;
i) Technical requirements other than the marked content;
j) Quantity of supply (m3);
k) The type, specification, grade and serial No. of inspection report of raw
materials;
l) Serial No. of concrete mixing ratio;
m) Quality evaluation of concrete.
10.3.2 During delivery, the demand-side shall specially assign a person to timely
confirm the quality and quantity of the ready-mixed concrete provided by the supply-
side.
10.3.3 The supply-side shall provide the demand-side with a shipping order of the
concrete with each transport vehicle. The shipping order shall at least include the
following contents:
a) Serial No. of contract;
b) Serial No. of shipping order;
c) The demand-side;
d) The supply-side;
e) Name of project;
...