Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
Explanation of Formulation
This standard is prepared on the basis of deep investigation, study and summary of practical application experience of high performance concrete for sea port engineering, in combination with construction development requirements of sea port engineering, and by referring to relevant technical standards at home and abroad and absorbing new research results as well as widely soliciting opinions. It mainly includes technical contents such as raw material quality control, mix proportion control, construction process quality control and quality acceptance control of high performance concrete.
Chief development organizations of this standard are CCCC Fourth Harbor Engineering Institute Co., Ltd. and CCCC Third Harbor Engineering Co., Ltd.; participating development organizations are China Communications Construction Co., Ltd., CCCC Fourth Harbor Engineering Co., Ltd., Shanghai Third Harbour Engineering Science & Technology Research Institute Co., Ltd., Tianjin Port Engineering Institute Ltd. of CCCC First Harbor Engineering Company Ltd. and CCCCC WuHan Harbour Engineering Design And Research Co., Ltd.
Along with the sustainable development of our port engineering construction, the scale of sea port is increasingly expanding, the tendency to open sea and deep water is enhancing, requirements for structure durability is improved; in order to improve the technical level of sea port engineering construction and ensure project quality, Department of Water Transport of the Ministry of Transport organized to establish this standard.
The provisions printed in bold type in 3.4.8 of this standard are compulsory and must be implemented strictly.
This standard comprises 7 chapters, 4 annexes and explanation of provisions. The work division of drafters of this standard is as follows:
1 - General Provisions: Pan Deqiang
2 - Terms: Pan Deqiang
3 - Basic Requirements: Pan Deqiang, Wang Shengnian and Tian Junfeng
4 - Raw Materials Quality Control: Jin Jianchang, Hu Liping and Huang Junzhe
5 - Mix Proportion Control: Wang Shengnian, Huang Junzhe, Huang Xiaoheng and Zhang Guozhi
6 - Construction Process Quality Control: Luo Bidan and Hu Liping
7 - Quality Acceptance Control: Huang Junzhe, Huang Xiaoheng, Zhang Guozhi and Tian Junfeng
Annex A~E: Pan Deqiang, Wang Shengnian and Huang Junzhe
This standard was approved by the Ministry of Transport on September 20, 2011, issued on July 19, 2012 and shall be implemented from August 1, 2012.
The Department of Water Transport of the Ministry of Transport is in charge of the administration and explanation of this standard. All relevant organizations are kindly invited to post the problems discovered in the using process and the opinions to the Department of Water Transport of the Ministry of Transport (Address: Technical Management Office of Department of Water Transport of the Ministry of Transport, No.11, Jianguomennei Street, Beijing City, 100736) and the Management Group of this standard (Address: CCCC Fourth Harbor Engineering Institute Co., Ltd., No. 157, Qianjin Road, Guangzhou City, 510230, Guangdong Province) for reference in future revision.
Quality Control Standard of High Performance Concrete for Sea Port Engineering
1 General Provisions
1.0.1 For the purpose of strengthening quality control of high performance concrete for sea port engineering, realizing reliable quality, advanced technology and economic feasibility, this standard is established.
1.0.2 This standard is applicable to the quality control of high performance concrete for sea port engineering. Other high performance concrete of marine environment may also refer to the provisions of this standard.
1.0.3 For the quality control of high performance concrete for sea port engineering, necessary inspection and test equipment shall be equipped, and necessary technical management and quality control system shall be established.
1.0.4 The quality control of high performance concrete for sea port engineering shall not only comply with the requirements of this standard, but also comply with those stipulated in the current relevant ones of the nation.
2 Terms
2.0.1
high performance concrete
the concrete manufactured with conventional materials and process, low water-cementations material ratio and large mixing amount of active additive under normal temperature, and it has high anti-chloride ion permeability, good dimensional stability, excellent workability and higher strength
2.0.2
cementitious material
the generic term for cement or the active mineral additive of cement, fly ash, granulated blast furnace slag powder and silica fume used for preparing concrete
2.0.3
durability design of high performance concrete
the process of determining relevant technical indexes and selecting various measures according to application condition in order to ensure required durability of high performance concrete
2.0.4
chloride ion diffusion coefficient
the parameter representing the transmission rate of chlorine ions from high concentration area to low concentration area in concrete
2.0.5
pre-mixed cementitious material
the cementitious material uniformly mixed through machine according to various portfolios of portland cement, granulated blast furnace slag powder, fly ash and silica fume
2.0.6
slump spread
the extended diameter after slumping of fresh concrete mixture
2.0.7
high performance concrete workability
general term of flowability, cohesiveness and water retention of high performance concrete mixture
3 Basic Requirements
3.1 General Requirements
3.1.1 For reinforced and prestressed concrete structure for sea port engineering, high performance concrete shall be adopted for splash zone and may be adopted for water level change zone and atmospheric zone as required.
3.1.2 Stable and high grade cement and additive, high-quality aggregate and high-efficiency water reducing agent matched with cement shall be selected to prepare high performance concrete.
3.2 Concrete Mixture
3.2.1 The following contents shall be inspected for high performance concrete mixture:
(1) Consistence and consistence loss:
(2) Chloride ion content;
(3) Inspect the uniformity when concrete mix proportion, component material, mixing equipment and mixing time change.
(4) Inspect air content for concrete mixture with anti-freezing requirements;
(5) Inspect the temperature for concrete mixture with temperature control requirements.
3.2.2 The consistence of high performance concrete mixture shall be represented by slump or slump spread. The test method for slump shall meet the relevant requirements of the current professional standard JTJ 270 Testing Code of Concrete for Port and Waterlog Engineering. When the slump is greater than 180mm, its consistence should be represented by slump spread, and its test method shall meet the relevant requirements of Annex A.
3.2.3 Consistence loss shall be considered for high performance concrete mixture, and the slump at pouring site should not be less than 120mm.
3.2.4 The actually measured values of slump and slump spread shall meet the following requirements:
(1) The permissible deviation of slump and design value is ± 20mm;
(2) The permissible deviation of slump spread and design value is ± 30mm;
(3) When the design value is a certain value range, the actually measured value shall meet the requirements of specified range.
3.2.5 High performance concrete mixture shall be mixed uniformly with consistent color and shall be free from any segregation and obvious bleeding phenomenon.
3.2.6 The test method for uniformity of high performance concrete mixture shall meet the requirements of the current national standard GB/T 9142 Concrete Mixers.
3.2.7 The test result for uniformity of high performance concrete mixture shall meet the following requirements:
(1) The relative error of mortar density measured value in concrete is not greater than 0.8%;
(2) The relative error of measured value of coarse aggregate content in unit volume concrete is not greater than 5%.
3.3 Strength Grade of High Performance Concrete
3.3.1 The strength grade of high performance concrete shall be determined according to the cube crushing strength standard value and its grade classification shall meet the requirements specified in Table 3.3.1.
Table 3.3.1 Strength Grade of High Performance Concrete
High performance concrete C40 C45 C50 C55 C60 C70 C80
Air-entrained high performance concrete C40 C45 C50 C55 - - -
3.3.2 The test for strength of high performance concrete shall meet the relevant requirements of the current professional standard JTJ 270 Testing Code of Concrete for Port and Waterlog Engineering.
3.3.3 For the production quality level of high performance concrete, the compressive strength standard deviation of accepted concrete may be calculated regularly in batches according to strength grade (sample quantity is not less than 25), and be divided according to those specified in Table 3.3.3; the production quality level shall achieve medium or above grade.
Table 3.3.3 Concrete Production Quality Level
Concrete strength class Standard deviation of concrete strength (MPa)
Good Medium Relatively bad
CA0~C60 ≤3.5 ≤4.5 >4.5
>C60 ≤4.5 ≤5.5 >5.5
3.4 Durability Requirements for High Performance Concrete
3.4.1 High performance concrete for sea port engineering shall be subject to durability design according to its environment and position on the building.
3.4.2 The position of concrete in marine environment on the building shall be divided meeting the requirements in Table 3.4.2.
Table 3.4.2 Position Division of Concrete in Marine Environment
Sheltering condition Division category Atmospheric zone Splash zone Water level change zone Underwater zone
With sheltering condition According to the design water level of port engineering Design high water level plus more than 1.5m Between the lower bound of atmospheric zone and the design high water level minus 1.0m Between the lower bound of splash zone and the design low water level minus 1.0m Between the lower bound of water level change zone and the mud surface
Without sheltering condition According to the design water level of port engineering Design high water level plus more than (η0+1.0m) Between the lower bound of atmospheric zone and the design high water level minus η0 Between the lower bound of splash zone and the design low water level minus 1.0m Between the lower bound of water level change zone and the mud surface
According to the astronomical tide level The highest astronomical tide level plus 0.7 times more than the 100-year significant wave height H1/3 Between the lower bound of atmospheric zone and the highest astronomical tide level minus the 100-year significant wave height H1/3 Between the lower bound of splash zone and the lowest astronomical tide level minus 0.2 times the 100-year significant wave height H1/3 Between the lower bound of water level change zone and the mud surface
Note: ① η0 is the wave crest surface height at H1% (the wave height when the cumulative frequency of wave train is 1%) under the conditions of the design high water level and a 50-year recurrence interval, m;
② When the calculated value of the upper bound of splash zone is less than the wharf surface elevation, the wharf surface elevation shall be taken as the upper bound of splash zone;
③ When the design water level of concrete structure for sea port engineering without sheltering condition cannot be calculated according to the relevant specifications of port engineering, the position division of concrete structure may be determined according to astronomical tide level;
④ If the member which cannot be segmented is at different positions, it shall be divided according to the position with high durability requirement.
3.4.3 The minimum thickness of concrete protective layer for steel bar in marine environment shall meet the requirements specified in Table 3.4.3.
Table 3.4.3 Minimum Thickness of Concrete Protective Layer for Steel Bar in Marine EnvironmentIn: mm
Building location Atmospheric zone Splash zone Water level change zone Underwater zone
Northern area 50 60 50 40
Southern area 50 65 50 40
Notes: ① The thickness of concrete protective layer refers to the minimum distance between the surface of main bar and the concrete surface;
② The value in this table is the protective layer thickness of main bar when stirrup diameter is 6mm; and when stirrup diameter is greater than 6mm, the protective layer thickness shall add 5mm according to the requirements of the table;
③ For the cast-in-situ concrete members located in water level change zone and splash zone, their protective layer thickness shall add 10~15mm according to the requirements of the table;
④ For the concrete of fine or thin member like wharf slab and pile located in splash zone, its minimum protective layer thickness shall be 50mm for southern and northern areas;
⑤ Southern area refers to the area with the monthly mean temperature in the annual coldest month higher than 0℃.
3.4.4 The minimum thickness of concrete protective layer for prestressed bars in marine environment shall meet the following requirements.
3.4.4.1 Where the member thickness is larger than or equal to 0.5m, the minimum thickness of concrete protective layer shall meet the requirements specified in Table 3.4.4.
Table 3.4.4 Minimum Thickness of Concrete Protective Layer for Prestressed Bar in Marine Environment In: mm
Location Atmospheric zone Splash zone Water level change zone Underwater zone
Protective layer thickness 65 80 65 65
① The member thickness refers to the member size in the direction of the specified minimum thickness of protective layer;
② The thickness of protective layer for post-tensioned prestressed bar refers to the minimum distance from the wall of reserved hole to the member surface;
③ In case of manufacturing members, if special construction process or special anti-corrosive measures are adopted and it is indeed ensured about the corrosion protection of steel bars upon sufficient technical demonstration, the thickness of protective layer may not be bound by the above requirements;
④ For the prestressed bar with effective prestress less than 400 NPa, its protective layer thickness shall meet the requirements specified in 3.4.3, and should not be less than 1.5 times of the main bar diameter.
3.4.4.2 Where the member thickness is less than 0.5m, the minimum thickness of concrete protective layer for prestressed bar shall be 2.5 times of prestressed bar diameter and also shall not be less than 50mm.
3.4.5 For the plain concrete structure for preparing constructional steel bar, the thickness of concrete protective layer for constructional bar shall not be less than 40mm, and shall not be less than 2.5 times of the diameter of constructional steel bar.
3.4.6 The maximum crack width of reinforced concrete during construction period shall not exceed the limit specified in Table 3.4.6. The surface crack shall be treated according to those specified in current professional standard JTS 202 Specifications for Concrete Construction of Port and Waterway Engineering.
Table 3.4.6 Maximum Crack Limit of Reinforced Concrete Member In: mm
Atmospheric zone Splash zone Water level change zone Underwater zone
0.20 0.20 0.25 0.30
3.4.7 The maximum limit value of chlorine ion in high performance concrete mixture shall meet the requirements specified in Table 3.4.7, and its test method shall meet the relevant requirements of the current professional standard JTJ 270 Testing Code of Concrete for Port and Waterlog Engineering.
Foreword II
Explanation of Formulation III
1 General Provisions
2 Terms
3 Basic Requirements
3.1 General Requirements
3.2 Concrete Mixture
3.3 Strength Grade of High Performance Concrete
3.4 Durability Requirements for High Performance Concrete
4 Raw Materials Quality Control
4.1 General Requirements
4.2 Cement
4.3 Additive
4.4 Fine Aggregate
4.5 Coarse Aggregate
4.6 Mixing Water
4.7 Admixtures
5 Mix Proportion Control
5.1 General Requirements
5.2 Mix Proportion Design of High Performance Concrete
5.3 Mix Proportion Design of Mass High Performance Concrete
5.4 Mix Proportion Design of Anti-freezing High Performance Concrete
6 Quality Control of Construction Process
6.1 Batching
6.2 Mixing
6.3 Transportation
6.4 Pouring
6.5 Curing
6.6 Crack Control Measures for High Performance Concrete
7 Quality Acceptable Control
7.1 Appearance Quality of High Performance Concrete
7.2 High Performance Concrete Strength
7.3 High Performance Concrete Durability
7.4 Treatment for High Performance Concrete Quality Problem
Annex A Slump Spread Test Method of High Performance Concrete
Annex B Electromigration Test Method of Diffusion Coefficient for Resistance of Concrete to Chlorine Ion Permeability
Annex C Immersion Test Method for Chloride Ion Diffusion Coefficient of Hardened Concrete
Annex D Service Life Calculation of Concrete Structure
Annex E Explanation of Expressions and Words in This Standard
Additional Explanations
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
Explanation of Formulation
This standard is prepared on the basis of deep investigation, study and summary of practical application experience of high performance concrete for sea port engineering, in combination with construction development requirements of sea port engineering, and by referring to relevant technical standards at home and abroad and absorbing new research results as well as widely soliciting opinions. It mainly includes technical contents such as raw material quality control, mix proportion control, construction process quality control and quality acceptance control of high performance concrete.
Chief development organizations of this standard are CCCC Fourth Harbor Engineering Institute Co., Ltd. and CCCC Third Harbor Engineering Co., Ltd.; participating development organizations are China Communications Construction Co., Ltd., CCCC Fourth Harbor Engineering Co., Ltd., Shanghai Third Harbour Engineering Science & Technology Research Institute Co., Ltd., Tianjin Port Engineering Institute Ltd. of CCCC First Harbor Engineering Company Ltd. and CCCCC WuHan Harbour Engineering Design And Research Co., Ltd.
Along with the sustainable development of our port engineering construction, the scale of sea port is increasingly expanding, the tendency to open sea and deep water is enhancing, requirements for structure durability is improved; in order to improve the technical level of sea port engineering construction and ensure project quality, Department of Water Transport of the Ministry of Transport organized to establish this standard.
The provisions printed in bold type in 3.4.8 of this standard are compulsory and must be implemented strictly.
This standard comprises 7 chapters, 4 annexes and explanation of provisions. The work division of drafters of this standard is as follows:
1 - General Provisions: Pan Deqiang
2 - Terms: Pan Deqiang
3 - Basic Requirements: Pan Deqiang, Wang Shengnian and Tian Junfeng
4 - Raw Materials Quality Control: Jin Jianchang, Hu Liping and Huang Junzhe
5 - Mix Proportion Control: Wang Shengnian, Huang Junzhe, Huang Xiaoheng and Zhang Guozhi
6 - Construction Process Quality Control: Luo Bidan and Hu Liping
7 - Quality Acceptance Control: Huang Junzhe, Huang Xiaoheng, Zhang Guozhi and Tian Junfeng
Annex A~E: Pan Deqiang, Wang Shengnian and Huang Junzhe
This standard was approved by the Ministry of Transport on September 20, 2011, issued on July 19, 2012 and shall be implemented from August 1, 2012.
The Department of Water Transport of the Ministry of Transport is in charge of the administration and explanation of this standard. All relevant organizations are kindly invited to post the problems discovered in the using process and the opinions to the Department of Water Transport of the Ministry of Transport (Address: Technical Management Office of Department of Water Transport of the Ministry of Transport, No.11, Jianguomennei Street, Beijing City, 100736) and the Management Group of this standard (Address: CCCC Fourth Harbor Engineering Institute Co., Ltd., No. 157, Qianjin Road, Guangzhou City, 510230, Guangdong Province) for reference in future revision.
Quality Control Standard of High Performance Concrete for Sea Port Engineering
1 General Provisions
1.0.1 For the purpose of strengthening quality control of high performance concrete for sea port engineering, realizing reliable quality, advanced technology and economic feasibility, this standard is established.
1.0.2 This standard is applicable to the quality control of high performance concrete for sea port engineering. Other high performance concrete of marine environment may also refer to the provisions of this standard.
1.0.3 For the quality control of high performance concrete for sea port engineering, necessary inspection and test equipment shall be equipped, and necessary technical management and quality control system shall be established.
1.0.4 The quality control of high performance concrete for sea port engineering shall not only comply with the requirements of this standard, but also comply with those stipulated in the current relevant ones of the nation.
2 Terms
2.0.1
high performance concrete
the concrete manufactured with conventional materials and process, low water-cementations material ratio and large mixing amount of active additive under normal temperature, and it has high anti-chloride ion permeability, good dimensional stability, excellent workability and higher strength
2.0.2
cementitious material
the generic term for cement or the active mineral additive of cement, fly ash, granulated blast furnace slag powder and silica fume used for preparing concrete
2.0.3
durability design of high performance concrete
the process of determining relevant technical indexes and selecting various measures according to application condition in order to ensure required durability of high performance concrete
2.0.4
chloride ion diffusion coefficient
the parameter representing the transmission rate of chlorine ions from high concentration area to low concentration area in concrete
2.0.5
pre-mixed cementitious material
the cementitious material uniformly mixed through machine according to various portfolios of portland cement, granulated blast furnace slag powder, fly ash and silica fume
2.0.6
slump spread
the extended diameter after slumping of fresh concrete mixture
2.0.7
high performance concrete workability
general term of flowability, cohesiveness and water retention of high performance concrete mixture
3 Basic Requirements
3.1 General Requirements
3.1.1 For reinforced and prestressed concrete structure for sea port engineering, high performance concrete shall be adopted for splash zone and may be adopted for water level change zone and atmospheric zone as required.
3.1.2 Stable and high grade cement and additive, high-quality aggregate and high-efficiency water reducing agent matched with cement shall be selected to prepare high performance concrete.
3.2 Concrete Mixture
3.2.1 The following contents shall be inspected for high performance concrete mixture:
(1) Consistence and consistence loss:
(2) Chloride ion content;
(3) Inspect the uniformity when concrete mix proportion, component material, mixing equipment and mixing time change.
(4) Inspect air content for concrete mixture with anti-freezing requirements;
(5) Inspect the temperature for concrete mixture with temperature control requirements.
3.2.2 The consistence of high performance concrete mixture shall be represented by slump or slump spread. The test method for slump shall meet the relevant requirements of the current professional standard JTJ 270 Testing Code of Concrete for Port and Waterlog Engineering. When the slump is greater than 180mm, its consistence should be represented by slump spread, and its test method shall meet the relevant requirements of Annex A.
3.2.3 Consistence loss shall be considered for high performance concrete mixture, and the slump at pouring site should not be less than 120mm.
3.2.4 The actually measured values of slump and slump spread shall meet the following requirements:
(1) The permissible deviation of slump and design value is ± 20mm;
(2) The permissible deviation of slump spread and design value is ± 30mm;
(3) When the design value is a certain value range, the actually measured value shall meet the requirements of specified range.
3.2.5 High performance concrete mixture shall be mixed uniformly with consistent color and shall be free from any segregation and obvious bleeding phenomenon.
3.2.6 The test method for uniformity of high performance concrete mixture shall meet the requirements of the current national standard GB/T 9142 Concrete Mixers.
3.2.7 The test result for uniformity of high performance concrete mixture shall meet the following requirements:
(1) The relative error of mortar density measured value in concrete is not greater than 0.8%;
(2) The relative error of measured value of coarse aggregate content in unit volume concrete is not greater than 5%.
3.3 Strength Grade of High Performance Concrete
3.3.1 The strength grade of high performance concrete shall be determined according to the cube crushing strength standard value and its grade classification shall meet the requirements specified in Table 3.3.1.
Table 3.3.1 Strength Grade of High Performance Concrete
High performance concrete C40 C45 C50 C55 C60 C70 C80
Air-entrained high performance concrete C40 C45 C50 C55 - - -
3.3.2 The test for strength of high performance concrete shall meet the relevant requirements of the current professional standard JTJ 270 Testing Code of Concrete for Port and Waterlog Engineering.
3.3.3 For the production quality level of high performance concrete, the compressive strength standard deviation of accepted concrete may be calculated regularly in batches according to strength grade (sample quantity is not less than 25), and be divided according to those specified in Table 3.3.3; the production quality level shall achieve medium or above grade.
Table 3.3.3 Concrete Production Quality Level
Concrete strength class Standard deviation of concrete strength (MPa)
Good Medium Relatively bad
CA0~C60 ≤3.5 ≤4.5 >4.5
>C60 ≤4.5 ≤5.5 >5.5
3.4 Durability Requirements for High Performance Concrete
3.4.1 High performance concrete for sea port engineering shall be subject to durability design according to its environment and position on the building.
3.4.2 The position of concrete in marine environment on the building shall be divided meeting the requirements in Table 3.4.2.
Table 3.4.2 Position Division of Concrete in Marine Environment
Sheltering condition Division category Atmospheric zone Splash zone Water level change zone Underwater zone
With sheltering condition According to the design water level of port engineering Design high water level plus more than 1.5m Between the lower bound of atmospheric zone and the design high water level minus 1.0m Between the lower bound of splash zone and the design low water level minus 1.0m Between the lower bound of water level change zone and the mud surface
Without sheltering condition According to the design water level of port engineering Design high water level plus more than (η0+1.0m) Between the lower bound of atmospheric zone and the design high water level minus η0 Between the lower bound of splash zone and the design low water level minus 1.0m Between the lower bound of water level change zone and the mud surface
According to the astronomical tide level The highest astronomical tide level plus 0.7 times more than the 100-year significant wave height H1/3 Between the lower bound of atmospheric zone and the highest astronomical tide level minus the 100-year significant wave height H1/3 Between the lower bound of splash zone and the lowest astronomical tide level minus 0.2 times the 100-year significant wave height H1/3 Between the lower bound of water level change zone and the mud surface
Note: ① η0 is the wave crest surface height at H1% (the wave height when the cumulative frequency of wave train is 1%) under the conditions of the design high water level and a 50-year recurrence interval, m;
② When the calculated value of the upper bound of splash zone is less than the wharf surface elevation, the wharf surface elevation shall be taken as the upper bound of splash zone;
③ When the design water level of concrete structure for sea port engineering without sheltering condition cannot be calculated according to the relevant specifications of port engineering, the position division of concrete structure may be determined according to astronomical tide level;
④ If the member which cannot be segmented is at different positions, it shall be divided according to the position with high durability requirement.
3.4.3 The minimum thickness of concrete protective layer for steel bar in marine environment shall meet the requirements specified in Table 3.4.3.
Table 3.4.3 Minimum Thickness of Concrete Protective Layer for Steel Bar in Marine EnvironmentIn: mm
Building location Atmospheric zone Splash zone Water level change zone Underwater zone
Northern area 50 60 50 40
Southern area 50 65 50 40
Notes: ① The thickness of concrete protective layer refers to the minimum distance between the surface of main bar and the concrete surface;
② The value in this table is the protective layer thickness of main bar when stirrup diameter is 6mm; and when stirrup diameter is greater than 6mm, the protective layer thickness shall add 5mm according to the requirements of the table;
③ For the cast-in-situ concrete members located in water level change zone and splash zone, their protective layer thickness shall add 10~15mm according to the requirements of the table;
④ For the concrete of fine or thin member like wharf slab and pile located in splash zone, its minimum protective layer thickness shall be 50mm for southern and northern areas;
⑤ Southern area refers to the area with the monthly mean temperature in the annual coldest month higher than 0℃.
3.4.4 The minimum thickness of concrete protective layer for prestressed bars in marine environment shall meet the following requirements.
3.4.4.1 Where the member thickness is larger than or equal to 0.5m, the minimum thickness of concrete protective layer shall meet the requirements specified in Table 3.4.4.
Table 3.4.4 Minimum Thickness of Concrete Protective Layer for Prestressed Bar in Marine Environment In: mm
Location Atmospheric zone Splash zone Water level change zone Underwater zone
Protective layer thickness 65 80 65 65
① The member thickness refers to the member size in the direction of the specified minimum thickness of protective layer;
② The thickness of protective layer for post-tensioned prestressed bar refers to the minimum distance from the wall of reserved hole to the member surface;
③ In case of manufacturing members, if special construction process or special anti-corrosive measures are adopted and it is indeed ensured about the corrosion protection of steel bars upon sufficient technical demonstration, the thickness of protective layer may not be bound by the above requirements;
④ For the prestressed bar with effective prestress less than 400 NPa, its protective layer thickness shall meet the requirements specified in 3.4.3, and should not be less than 1.5 times of the main bar diameter.
3.4.4.2 Where the member thickness is less than 0.5m, the minimum thickness of concrete protective layer for prestressed bar shall be 2.5 times of prestressed bar diameter and also shall not be less than 50mm.
3.4.5 For the plain concrete structure for preparing constructional steel bar, the thickness of concrete protective layer for constructional bar shall not be less than 40mm, and shall not be less than 2.5 times of the diameter of constructional steel bar.
3.4.6 The maximum crack width of reinforced concrete during construction period shall not exceed the limit specified in Table 3.4.6. The surface crack shall be treated according to those specified in current professional standard JTS 202 Specifications for Concrete Construction of Port and Waterway Engineering.
Table 3.4.6 Maximum Crack Limit of Reinforced Concrete Member In: mm
Atmospheric zone Splash zone Water level change zone Underwater zone
0.20 0.20 0.25 0.30
3.4.7 The maximum limit value of chlorine ion in high performance concrete mixture shall meet the requirements specified in Table 3.4.7, and its test method shall meet the relevant requirements of the current professional standard JTJ 270 Testing Code of Concrete for Port and Waterlog Engineering.
Contents of JTS 257-2-2012
Foreword II
Explanation of Formulation III
1 General Provisions
2 Terms
3 Basic Requirements
3.1 General Requirements
3.2 Concrete Mixture
3.3 Strength Grade of High Performance Concrete
3.4 Durability Requirements for High Performance Concrete
4 Raw Materials Quality Control
4.1 General Requirements
4.2 Cement
4.3 Additive
4.4 Fine Aggregate
4.5 Coarse Aggregate
4.6 Mixing Water
4.7 Admixtures
5 Mix Proportion Control
5.1 General Requirements
5.2 Mix Proportion Design of High Performance Concrete
5.3 Mix Proportion Design of Mass High Performance Concrete
5.4 Mix Proportion Design of Anti-freezing High Performance Concrete
6 Quality Control of Construction Process
6.1 Batching
6.2 Mixing
6.3 Transportation
6.4 Pouring
6.5 Curing
6.6 Crack Control Measures for High Performance Concrete
7 Quality Acceptable Control
7.1 Appearance Quality of High Performance Concrete
7.2 High Performance Concrete Strength
7.3 High Performance Concrete Durability
7.4 Treatment for High Performance Concrete Quality Problem
Annex A Slump Spread Test Method of High Performance Concrete
Annex B Electromigration Test Method of Diffusion Coefficient for Resistance of Concrete to Chlorine Ion Permeability
Annex C Immersion Test Method for Chloride Ion Diffusion Coefficient of Hardened Concrete
Annex D Service Life Calculation of Concrete Structure
Annex E Explanation of Expressions and Words in This Standard
Additional Explanations
