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According to the requirements of the document "Notice on Printing and Publishing 'Development and Revision Plan of Engineering Construction Standards and Specifications in 2007 (first batch)'" (Jian Biao [2007] No. 125) issued by the former Ministry of Construction, This code is revised by China Northeast Architecture Design and Research Institute Co., Ltd. together with organizations concerned based on "Code for Design of Masonry Structures" GB 50003-2001.
During the revision process, the drafting group considered the economic conditions and the current status of masonry structures according to the principle of "supplement, simplification and perfection", summarized new experience in the application of masonry structures in recent years, investigated the earthquake resistance hazard of masonry structures in Wenchuan and Yushu earthquake, conducted necessary test research and supplemented clauses for local new masonry materials emerging in energy conservation and emission reduction and wall material innovation environment by reference to the mature achievements of scientific research in masonry structure field, and perfected relevant content of masonry structure durability, detailing requirements, reinforced concrete masonry members, earthquake resistance design for masonry structure members, etc., meanwhile, conducted necessary simplification for adjustment coefficient of masonry strength, etc.
The revised contents extensively solicited for the comment and suggestion of relevant design, scientific research, teaching, construction, enterprise and relevant management department nationwide, and finally finalized upon review through multiple repeat discussion, modification and replenishment.
This code comprises 10 chapters and 4 appendixes, with main technical content including: general provisions, terms and symbols, materials, basic rules on design, unreinforced masonry members, detailing requirements, ring beams, lintels, wall beams and cantilever beams, reinforced brick masonry members, reinforced concrete masonry members, earthquake resistance design for masonry structure members, etc.
Main revised contents of this code: add mature and feasible new masonry materials which adapt energy conservation and emission reduction and wall material innovation requirements and propose corresponding design method; revise evaluation method of local masonry strength according to test research and simplify the adjustment coefficient of masonry strength; add the relevant requirements for increasing masonry durability; perfect detailing requirements of masonry structures; supplement measures for preventing or relieving wall cracking caused by material deformation with respect to crack problems existing in new masonry material wall; perfect and supplement detailing requirements for the design of cavity wall filled with insulation; supplement the calculation method of eccentric compression outside masonry composite wall plane; enlarge the application scope of reinforced concrete masonry structure, add design requirements for frame-supported reinforced masonry block shear wall building; perfect earthquake resistance design method for masonry structures according to earthquake resistance hazard and in combination with masonry structure characteristic, and supplement earthquake resistance design method for infilled wall in concrete frame structure.
The provisions printed in bold type are compulsory ones in this code and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this code and the explanation of compulsory provisions, and China Northeast Architecture Design and Research Institute Co., Ltd. is responsible for the explanation of the specific technical contents. During the process of implementing this code, all organizations are kindly requested to seriously sum up experience in combination with engineering practice, post or pass opinions and advice on to the Administrative Group of "Code for Design of Masonry Structures" of China Northeast Architecture Design and Research Institute Co., Ltd. (address: No. 65, Guangrong Street, Heping District, Shenyang City, China, 110003, Email: gaoly@masonry.cn) for future reference.
Chief development organization, participating development organizations, participating organization, chief drafting staff and chief examiners of this code:
Chief development organization: China Northeast Architecture Design and Research Institute Co., Ltd.
Participating development organizations: China National Machinery Industry Corporation
Hunan University
Changsha University of Science and Technology
Zhejiang University
Harbin Institute of Technology
Xi'an University of Architecture and Technology
Chongqing Institute of Building Research
Tongji University
Beijing Institute of Architectural Design
Chongqing University
Yunnan Building Technology Development Center
Guangzhou Civil Architecture Research & Design Institute
Shenyang Jianzhu University
Zhengzhou University
Shaanxi Research Institute of Building Sciences
Institute of Engineering Mechanics, China Earthquake Administration
Nanjing University of Technology
Sichuan Institute of Building Research
Participating organization: Guizhou Kailin Phosphorus Industry Co., Ltd.
Chief drafting staff: Gao Lianyu, Xu Jian, Yuan Zhenfang, Shi Chuxian, Liang Jianguo, Yan Jiaxi, Tang Daixin, Lin Wenxiu, Liang Xingwen, Gong Shaoxi, Zhou Bingzhang, Wu Mingshun, Jin Weiliang, Liu Bin, Xue Huili, Cheng Caiyuan, Li Xiang, Luo Wankang, Yang Weijun, Hu Qiugu, Wang Fenglai, He Jiangang, Zhang Xingfu, Zhao Chengwen, Huang Jing, Wang Qinglin, Liu Lixin, Xie Lili, Liu Ming, Xiao Xiaosong, Qin Shihong, Lei Bo, Jiang Kai, Yu Zuguo, Xiong Lihong, Hou Ruxin, Yue Zengguo, Guo Zhanggen
Chief examiners: Zhou Fulin, Sun Weimin, Ma Jianxun, Wang Cungui, You Shiqi, Chen Zhengxiang, Zhang Youliang, Zhang Jingjie, Gu Xianglin
Contents
1 General Provisions 1
2 Terms and Symbols 1
2.1 Terms 1
2.2 Symbols 5
3 Materials 8
3.1 Strength Class of Materials 8
3.2 Calculation Data of Masonry 9
4 Basic Rules on Design 14
4.1 Principles of Design 14
4.2 Stipulations for Static Calculation of Buildings 16
4.3 Rules on Durability 20
5 Unreinforced Masonry Members 22
5.1 Compression Members 22
5.2 Local Compression 24
5.3 Members Subjected to Axial Tensile Load 28
5.4 Members Subjected to Bending 28
5.5 Members Subjected to Shear 29
6 Detailing Requirements 29
6.1 Verification for Slenderness Ratio of Wall and Column 29
6.2 General Detailing Requirements 31
6.3 Frame Filled Wall 34
6.4 Cavity Wall Filled with Insulation 35
6.5 Main Measures to Prevent Walls from Cracking 36
7 Ring Beams, Lintels, Wall Beams and Cantilever Beams 39
7.1 Ring Beams 39
7.2 Lintels 40
7.3 Wall Beams 41
7.4 Cantilever Beams 48
8 Reinforced Brick Masonry Members 51
8.1 Mesh-reinforced Brick Masonry Members 51
8.2 Composite Brick Masonry Members 52
9 Reinforced Concrete Masonry Members 58
9.1 General Requirements 58
9.2 Calculation of Reinforced Masonry Members Subjected to Axial Compression 58
9.3 Calculation of Reinforced Masonry Members Subjected to Shear 62
9.4 Detail Stipulation of Reinforced Concrete Masonry Shear Walls 64
10 Earthquake Resistance Design for Masonry Structure Members 68
10.1 General Requirements 68
10.2 Brick Masonry Members 75
10.3 Concrete Masonry Members 80
10.4 Earthquake Resistant Elements of Masonry Buildings with Bottom Frames 83
10.5 Earthquake Resistant Wall of Reinforced Concrete Masonry 88
Appendix A Specification and Dimension of Stone Materials and the Method for Defining the Strength Grades of Stone Materials 94
Appendix B Calculating Formulas for Strength Mean Values of Various Kinds of Masonry and Their Characteristic Strength Values 95
Appendix C Statical Calculation of "Semi-rigid" Buildings 98
Appendix D Influence Coefficients ψ and ψn 99
Explanation of Wording in This Code 106
List of Quoted Standards 107
1 General Provisions
1.0.1 This code is formulated with a view to implementing the technical and economic policies of the nation, persisting in wall material innovation, adjusting measures to local conditions, using local materials, reasonably selecting structural scheme and masonry materials, and achieving advanced technology, safety and usability, economy and rationality and quality guarantee.
1.0.2 This code is applicable to the design of the following masonry structures in building engineering, and the design for special conditions or with specific requirements shall be carried out according to special requirements:
1 Brick masonry: including unreinforced and reinforced masonry of fired common brick, fired perforated brick, autoclaved sand-lime brick, autoclaved flyash-lime brick, common concrete brick and perforated concrete brick;
2 Block masonry: including unreinforced and reinforced masonry of concrete block and light aggregate concrete block;
3 Stone masonry: including masonry of various squared stones and rubbles.
1.0.3 This code is established according to the principle specified in the current national standard "Unified Standard Reliability Design of Building Structures" GB 50068. The design terms and symbols are adopted according to the requirements of the current national standard "Standard for Terminology and Symbols Used in Design of Building Structures" GB/T 50083.
1.0.4 For design according to this code, the load shall comply with the current national standard "Load Code for the Design of Building Structures" GB 50009; the selection and application of wall materials shall comply with the current national standard "Uniform Technical Code for Wall Material used in Buildings" GB 50574; the selection of concrete materials shall meet the requirements of the current national standard "Code for Design of Concrete Structures" GB 50010; the construction quality control shall meet the requirements of the current national standards "Code for Acceptance of Constructional Quality of Masonry Structures" GB 50203 and "Code for Acceptance of Constructional Quality of Concrete Structures" GB 50204; and the structural earthquake resistance design shall meet the relevant requirements of the current national standard "Code for Seismic Design of Buildings" GB 50011.
1.0.5 The masonry structure design shall not only comply with this code, but also those in the current relevant ones of the nation.
2 Terms and Symbols
2.1 Terms
2.1.1 Masonry structure
Structure that wall and column built with block and mortar are used as the main loaded members of the building. It is the general term of brick masonry, block masonry and stone masonry structure.
2.1.2 Reinforced masonry structure
Structure that the reinforced masonry is used as the main loaded member of the building. It is the general term of mesh-reinforced masonry column, horizontal reinforced masonry wall, brick masonry and reinforced concrete layer or composite masonry column (wall) of reinforced mortar layer, composite wall of brick masonry and structural reinforced concrete column and reinforced concrete masonry shear wall structure.
2.1.3 Reinforced concrete masonry shear wall structure
Building structure composed of reinforced concrete masonry shear wall bearing vertical and horizontal action and concrete floor and roof.
2.1.4 Fired common brick
Roasted solid brick which takes coal gangue, shale, flyash or clay as the major raw materials, including fired coal gangue brick, fired shale brick, fired flyash brick, fired clay brick, etc.
2.1.5 Fired perforated brick
Fired brick that takes coal gangue, shale, flyash or clay as the major raw materials, with void ratio not greater than 35%, with small and more holes, and is mainly used for bearing position.
2.1.6 Autoclaved sand-lime brick
Solid brick which takes limy materials such as lime and siliceous materials such as sand as the major raw materials and is formed through blank preparation, pressing exhaust forming and autoclave curing.
2.1.7 Autoclaved flyash-lime brick
Solid brick which takes limy materials such as lime, slaked lime (carbide slag) or cement and siliceous materials such as flyash as well as aggregates (sand, etc.) as the major raw materials, adds an adequate amount of gypsum, and is formed through blank preparation, pressing exhaust forming and autoclave curing.
2.1.8 Concrete small hollow block
Hollow block which is made of ordinary concrete or light aggregate concrete, with a main dimension of 390mm×190mm×190mm and hollow ratio of 25%~50%, referred to as concrete block or masonry block.
2.1.9 Concrete brick
A perforated concrete half blind hole brick or solid brick which takes cement as cementitious material and sand, stone, etc. as the main aggregates and is made through mixing with water, forming and curing. The main dimensions of perforated bricks are 240mm×115mm×90mmm, 240mm×190mm×90mm, 190mm×190mmm×90mm, etc.; the main dimensions of solid bricks are 240mm×115mm×53mm, 240mm×115mm×90mm, etc.
2.1.10 Mortar for concrete small hollow block
Masonry mortar which is made by mechanically mixing such compositions as cement, sand, water and admixtures and additives added as required according to a certain proportion and is exclusively used for building concrete block, referred to as mortar for masonry block.
2.1.11 Grout for concrete small hollow block
Concrete which is made by mechanically mixing such compositions as cement, aggregate, water and admixtures and additives added as required according to a certain proportion and is used for concreting block masonry core column or other holes to be filled, referred to as block grout concrete.
2.1.12 Mortar for autoclaved silicate brick
Mortar which is made by mechanically mixing such compositions as cement, sand, water and admixtures and additives added as required according to a certain proportion and is exclusively used for building autoclaved lime-sand brick or autoclaved flyash brick masonry and the masonry shear strength shall not be less than the value of fired common brick masonry.
2.1.13 Pilastered wall
Buttressed wall which is formed by locally thickening the wall along the wall length direction at a certain interval.
2.1.14 Structural concrete column
Concrete column which is made according to the construction sequence of wall building first and then concrete column pouring based on structural reinforcement in the specified position of masonry building wall. Generally, it is referred to as structural concrete column, and structural column for short.
2.1.15 Ring beam
Sealed concrete beam member according to structural reinforcement, arranged along the horizontal direction of masonry wall at building eave, window top, storey, crane beam top or foundation top elevation.
2.1.16 Wall beam
Combined member composed of reinforced concrete joist and masonry wall within the range of calculation height on the beam, including simply-supported wall beam, continuous wall beam and frame-supported wall beam.
2.1.17 Cantilever beam
Cantilever reinforced concrete beam which is embedded in masonry. It general refers to balcony cantilever beam, awning cantilever beam or veranda cantilever beam in the building.
2.1.18 Design working life
Period specified in the design. During this period, the structure or structural member only needs normal maintenance for use according to its preset purpose, without overhaul reinforcement.
2.1.19 Static analysis scheme of building
Static analysis diagram of structure determined according to the space working performance of building. The static analysis scheme of building covers rigid analysis scheme, rigid-elastic analysis scheme and elastic analysis scheme.
2.1.20 Rigid analysis scheme
Static analysis scheme made for wall and column according to floor and roof as horizontally fixed hinged support.
2.1.21 Rigid-elastic analysis scheme
Static analysis scheme made for wall and column according to floor, roof and wall and column as hinged connection and in consideration of space working bent frame or frame.
2.1.22 Elastic analysis scheme
Scheme of static analysis for wall and column according to floor, roof and wall and column as hinged connection and without consideration of space working plane bent frame or frame.
2.1.23 Upper flexible and lower rigid complex multistorey building
Multistorey building that the top storey fails to meet the rigid analysis scheme requirements but the lower storeys meet the rigid analysis scheme requirements in structural analysis.
2.1.24 Types of roof or floor structure
Classification of roof and floor according to the structure detailing and corresponding rigidity of roof and floor. According to the common structure, the roof and floor may be divided into three types, but the horizontal rigidity of each type of roof and floor is approximately same.
2.1.25 Ratio of height to sectional thickness of wall or column
Ratio of calculation height to specified thickness of masonry wall and column. The specified thickness shall take the wall thickness for wall and the corresponding side length for column, and the sectional converted thickness for pilastered wall.
2.1.26 Effective support length of beam end
Distribution length of compressive stress of beam end on masonry or rigid cushion block interface along bean span direction.
2.1.27 Calculating overturning point
Rotating center taken as required for verifying the cantilever beam overturning resistance.
2.1.28 Expansion and contraction joint
Vertical joint with free expansion and contraction after the building is divided into two or several independent units, generally including double-wall expansion and contraction joint, double-column expansion and contraction joint, etc.
2.1.29 Control joint
Joint that the wall is divided into several independent wall limbs, and the wall limb is allowed with free deformation in its plane and has adequate resistivity against external force.
2.1.30 Category of construction quality control
Masonry construction quality control category divided according to quality assurance system of construction site, mortar and concrete strength, and comprehensive level of technical grade of masonry worker.
2.1.31 Confined masonry member
Masonry member which has restraint action by respectively arranging structural reinforced concrete column and ring-beam on both sides and upper and lower positions of unreinforced masonry wall piece for the purpose of increasing the ductility and resistance of unreinforced masonry wall piece.
2.1.32 Infilled wall in concrete frame structure
Wall which is built in frame structure.
2.1.33 Cavity wall filled with insulation
Wall that the continuous cavity reserved in the wall is filled with thermal insulating or heat insulating material and antirust metal tie is used to connect between interior side and exterior side of the wall.
2.1.34 Adjustable tie
Tie which is embedded in mortar joint of interior and exterior side of cavity wall filled with insulation and utilizes adjustable behavior to eliminate adverse effect generated by inconsistency of vertical deformation for interior and exterior side.
2.2 Symbols
2.2.1 Material property
MU——Strength class of block;
M——Strength class of common mortar;
Mb——Strength class of mortar for concrete small hollow block;
Ms——Strength class of mortar for autoclaved silicate brick;
C——Concrete strength class;
Cb——Strength class of grout for concrete small hollow block;
f1——Compressive strength class value or mean value of block;
f2——Compressive strength mean value of mortar;
f and fk——Design value and characteristic value of compressive strength of masonry;
fg——Design value of compressive strength of single-row hole and perforated concrete block grout masonry (referred to as design value of compressive strength of grout masonry);
fvg——Design value of shear strength of single-row hole and perforated concrete block grout masonry (referred to as design value of shear strength of grout masonry);
ft and ft,k——Design value and characteristic value of axial tensile strength of masonry;
ftm and ftm,k——Design value and characteristic value of bending tensile strength of masonry;
fv and fv,k——Design value and characteristic value of shear strength of masonry;
fVE——Design value of earthquake resistance shear strength damaged along the stepped section of masonry;
fn——Design value of compressive strength of mesh-reinforced brick masonry;
fy and ——Design value of tensile and compressive strength of steel bar;
fc——Design value of axial compressive strength of concrete;
E——Elastic modulus of masonry;
Ec——Elastic modulus of concrete;
G——Shear modulus of masonry.
2.2.2 Action and action effect
N——Design value of axial force;
Nl——Design value of axial force on local compression area and bearing pressure of beam end;
N0——Design value of upper axial force;
Nt——Design value of axial tension;
M——Design value of bending moment;
Mr——Design value of anti-overturning moment of cantilever beam;
Mov——Design value of overturning moment of cantilever beam;
V——Design value of shear force;
F1——Design value of concentrated load on top of joist;
Q1——Design value of evenly distributed load on top of joist;
Q2——Design value of evenly distributed load on top of wall beam;
σ0——Mean compressive stress of horizontal section.
2.2.3 Geometric parameters
A——Sectional area;
Ab——Area of cushion block;
Ac——Sectional area of structural concrete column;
Al——Local compression zone;
An——Clear sectional area of wall;
A0——Calculation area affecting local compressive strength;
As and ——Sectional area of tensioned and compressed steer bar;
a——Actual support length distance of side length and beam end;
ai——Distance from opening side to the nearest support center of wall beam;
a0——Effective support length of beam end;
as and ——Distance from center of gravity of longitudinal tensioned and compressed steer bar to the proximal edge of cross section;
b——Sectional width and side length;
bc——Width of structural concrete column along wall length direction;
bf——Calculated sectional flange width of pilastered wall and calculated width of wing wall;
——Flange calculation width of T-shaped and inverse L-shaped sectional compression zone;
bs——Door and window opening width within the distance range between adjacent transverse wall and wall between windows or between wall columns;
c and d——Distance;
e——Eccentricity of axial force;
H——Wall height and member height;
Hi——Storey height;
H0——Calculation height of member and calculation height of wall beam midspan section;
h——Wall thickness, smaller side length of rectangular section, side length along eccentric axial force direction of rectangular section, sectional height;
hb——Joist height;
h0——Effective height of section and converted height of cushion girder;
hT——Converted thickness of T-shaped section;
hw——Wall height and calculated sectional height of wall for wall beam;
l——Spacing between structural columns;
l0——Calculation span of beam;
ln——Clear span of beam;
I——Sectional moment of inertia;
i——Gyration radius of section;
s——Spacing and sectional moment of area;
x0——Distance between calculating overturning point and outer edge of wall;
umax——Maximum horizontal displacement;
W——Section resistance moment;
y——Distance from section gravity center to section edge of axial force in eccentric direction;
z——Internal force arm.
2.2.4 Calculation coefficient
α——Ratio of grout concrete area in block masonry to gross area of masonry, correction coefficient and coefficient;
αM——Bending moment coefficient of joist in consideration of the combination action of wall beam;
β——Slenderness ratio of member;
[β]——Allowable slenderness ratio of wall and column;
βV——Shear coefficient of joist in consideration of the combination action of wall beam;
γ——Improvement coefficient of local compressive strength of masonry, coefficient;
γa——Adjustment coefficient;
γf——Partial coefficient of structural member property;
γ0——Significance coefficient of structure;
γG——Partial coefficient of permanent load;
γRE——Earthquake resistance adjustment coefficient of bearing capacity;
δ——Void ratio of concrete block, coefficient;
ζ——Local compressive coefficient of masonry at the upper part of joist support;
ζc——Participation service coefficient of core column;
ζs——Participation service coefficient of steel bar;
ηi——Influence coefficient of space property of building;
ηc——Restraint correction coefficient of wall;
ηN——Joist midspan axial force coefficient in consideration of the combination action of wall beam;
λ——Shear-span ratio of calculation section;
μ——Correction coefficient, influence coefficient of composite shear and compressive force;
μ1——Correction coefficient of allowable slenderness ratio of self-bearing wall;
μ2——Correction coefficient of allowable slenderness ratio of wall with door and window opening;
μc——Improvement coefficient of allowable slenderness ratio of wall arranged with structural column;
ξ——Relative height of sectional compression zone, coefficient;
ξb——Limit of relative height of compression zone;
ξ1——Influence coefficient of wing wall or structural column to shear bearing capacity of wall for wall beam;
ξ2——Influence coefficient of opening to shear bearing capacity of wall for wall beam;
ρ——Ratio of grouting and ratio of reinforcement of concrete masonry;
ρs——Horizontal steel bar area ratio calculated according to vertical section of interlayer wall;
φ——Influence coefficient of bearing capacity, coefficient;
φn——Influence coefficient of bearing capacity of mesh-reinforced brick masonry member;
φ0——Stability coefficient of axial compression member;
φcom——Stability coefficient of composite brick masonry member;
ψ——Reduction coefficient;
ψM——Influence coefficient of opening to joist bending moment.
3 Materials
3.1 Strength Class of Materials
3.1.1 The strength class of bearing structure block shall be adopted according to the following requirements:
1 Strength class of fired common brick and fired perforated brick: MU30, MU25, MU20, MU15 and MU10;
2 Strength class of autoclaved sand-lime brick and autoclaved flyash-lime brick: MU25, MU20 and MU15;
3 Strength class of common concrete brick and perforated concrete brick: MU30, MU25, MU20 and MU15;
4 Strength class of concrete block and light aggregate concrete block: MU20, MU15, MU10, MU7.5 and MU5;
5 Strength class of stone: MU100, MU80, MU60, MU50, MU40, MU30 and MU20.
Notes: 1 The void ratio of light aggregate concrete block masonry with double-row hole or multi-row hole for bearing shall not be greater than 35%;
2 The folding-pressure ratio limit of perforated brick and autoclaved siliceous brick for bearing, the limit of void ratio, wall and rib dimension of perforated brick of non-sintered material for bearing as well as the carbonization and softening performance requirements shall meet the relevant requirements of the current national standard "Uniform Technical Code for Wall Material used in Buildings" GB 50574;
3 The specification, dimension and strength class of stone may be determined in accordance with the method in Appendix A of this code.
3.1.2 The strength class of hollow brick and light aggregate concrete block of the self-bearing wall shall be adopted according to the following requirements:
1 Strength class of hollow brick: MU10, MU7.5, MU5 and MU3.5;
2 Strength class of light aggregate concrete block: MU10, MU7.5, MU5 and MU3.5.
3.1.3 The strength class of mortar shall be adopted according to the following requirements:
1 Strength class of common mortar adopted by fired common brick, fired perforated brick, autoclaved sand-lime brick and autoclaved flyash-lime brick: M15, M10, M7.5, M5 and M2.5; strength class of dedicated masonry mortar adopted by autoclaved sand-lime brick and autoclaved flyash-lime brick masonry: Ms15, Ms10, Ms7.5 and Ms5.0;
2 Strength class of mortar adopted by common concrete brick, perforated concrete brick, concrete block with single-row hole and gangue concrete block masonry: Mb20, Mb15, Mb10, Mb7.5 and Mb5;
3 Strength class of mortar adopted by light aggregate concrete block masonry with double-row hole or multi-row hole: Mb10, Mb7.5 and Mb5;
4 Strength class of mortar adopted by untrimmed squared stone and rubble masonry: M7.5, M5 and M2.5.
Note: In determination of strength class of mortar, the block of the same kind shall be adopted as the bottom formwork of test block for mortar strength.
1 General Provisions
2 Terms and Symbols
2.1 Terms
2.2 Symbols
3 Materials
3.1 Strength Class of Materials
3.2 Calculation Data of Masonry
4 Basic Rules on Design
4.1 Principles of Design
4.2 Stipulations for Static Calculation of Buildings
4.3 Rules on Durability
5 Unreinforced Masonry Members
5.1 Compression Members
5.2 Local Compression
5.3 Members Subjected to Axial Tensile Load
5.4 Members Subjected to Bending
5.5 Members Subjected to Shear
6 Detailing Requirements
6.1 Verification for Slenderness Ratio of Wall and Column
6.2 General Detailing Requirements
6.3 Frame Filled Wall
6.4 Cavity Wall Filled with Insulation
6.5 Main Measures to Prevent Walls from Cracking
7 Ring Beams, Lintels, Wall Beams and Cantilever Beams
7.1 Ring Beams
7.2 Lintels
7.3 Wall Beams
7.4 Cantilever Beams
8 Reinforced Brick Masonry Members
8.1 Mesh-reinforced Brick Masonry Members
8.2 Composite Brick Masonry Members
9 Reinforced Concrete Masonry Members
9.1 General Requirements
9.2 Calculation of Reinforced Masonry Members Subjected to Axial Compression
9.3 Calculation of Reinforced Masonry Members Subjected to Shear
9.4 Detail Stipulation of Reinforced Concrete Masonry Shear Walls
10 Earthquake Resistance Design for Masonry Structure Members
10.1 General Requirements
10.2 Brick Masonry Members
10.3 Concrete Masonry Members
10.4 Earthquake Resistant Elements of Masonry Buildings with Bottom Frames
10.5 Earthquake Resistant Wall of Reinforced Concrete Masonry
Appendix A Specification and Dimension of Stone Materials and the Method for Defining the Strength Grades of Stone Materials
Appendix B Calculating Formulas for Strength Mean Values of Various Kinds of Masonry and Their Characteristic Strength Values
Appendix C Statical Calculation of "Semi-rigid" Buildings
Appendix D Influence Coefficients ψ and ψn
Explanation of Wording in This Code
List of Quoted Standards
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.
According to the requirements of the document "Notice on Printing and Publishing 'Development and Revision Plan of Engineering Construction Standards and Specifications in 2007 (first batch)'" (Jian Biao [2007] No. 125) issued by the former Ministry of Construction, This code is revised by China Northeast Architecture Design and Research Institute Co., Ltd. together with organizations concerned based on "Code for Design of Masonry Structures" GB 50003-2001.
During the revision process, the drafting group considered the economic conditions and the current status of masonry structures according to the principle of "supplement, simplification and perfection", summarized new experience in the application of masonry structures in recent years, investigated the earthquake resistance hazard of masonry structures in Wenchuan and Yushu earthquake, conducted necessary test research and supplemented clauses for local new masonry materials emerging in energy conservation and emission reduction and wall material innovation environment by reference to the mature achievements of scientific research in masonry structure field, and perfected relevant content of masonry structure durability, detailing requirements, reinforced concrete masonry members, earthquake resistance design for masonry structure members, etc., meanwhile, conducted necessary simplification for adjustment coefficient of masonry strength, etc.
The revised contents extensively solicited for the comment and suggestion of relevant design, scientific research, teaching, construction, enterprise and relevant management department nationwide, and finally finalized upon review through multiple repeat discussion, modification and replenishment.
This code comprises 10 chapters and 4 appendixes, with main technical content including: general provisions, terms and symbols, materials, basic rules on design, unreinforced masonry members, detailing requirements, ring beams, lintels, wall beams and cantilever beams, reinforced brick masonry members, reinforced concrete masonry members, earthquake resistance design for masonry structure members, etc.
Main revised contents of this code: add mature and feasible new masonry materials which adapt energy conservation and emission reduction and wall material innovation requirements and propose corresponding design method; revise evaluation method of local masonry strength according to test research and simplify the adjustment coefficient of masonry strength; add the relevant requirements for increasing masonry durability; perfect detailing requirements of masonry structures; supplement measures for preventing or relieving wall cracking caused by material deformation with respect to crack problems existing in new masonry material wall; perfect and supplement detailing requirements for the design of cavity wall filled with insulation; supplement the calculation method of eccentric compression outside masonry composite wall plane; enlarge the application scope of reinforced concrete masonry structure, add design requirements for frame-supported reinforced masonry block shear wall building; perfect earthquake resistance design method for masonry structures according to earthquake resistance hazard and in combination with masonry structure characteristic, and supplement earthquake resistance design method for infilled wall in concrete frame structure.
The provisions printed in bold type are compulsory ones in this code and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development of the People's Republic of China is in charge of the administration of this code and the explanation of compulsory provisions, and China Northeast Architecture Design and Research Institute Co., Ltd. is responsible for the explanation of the specific technical contents. During the process of implementing this code, all organizations are kindly requested to seriously sum up experience in combination with engineering practice, post or pass opinions and advice on to the Administrative Group of "Code for Design of Masonry Structures" of China Northeast Architecture Design and Research Institute Co., Ltd. (address: No. 65, Guangrong Street, Heping District, Shenyang City, China, 110003, Email: gaoly@masonry.cn) for future reference.
Chief development organization, participating development organizations, participating organization, chief drafting staff and chief examiners of this code:
Chief development organization: China Northeast Architecture Design and Research Institute Co., Ltd.
Participating development organizations: China National Machinery Industry Corporation
Hunan University
Changsha University of Science and Technology
Zhejiang University
Harbin Institute of Technology
Xi'an University of Architecture and Technology
Chongqing Institute of Building Research
Tongji University
Beijing Institute of Architectural Design
Chongqing University
Yunnan Building Technology Development Center
Guangzhou Civil Architecture Research & Design Institute
Shenyang Jianzhu University
Zhengzhou University
Shaanxi Research Institute of Building Sciences
Institute of Engineering Mechanics, China Earthquake Administration
Nanjing University of Technology
Sichuan Institute of Building Research
Participating organization: Guizhou Kailin Phosphorus Industry Co., Ltd.
Chief drafting staff: Gao Lianyu, Xu Jian, Yuan Zhenfang, Shi Chuxian, Liang Jianguo, Yan Jiaxi, Tang Daixin, Lin Wenxiu, Liang Xingwen, Gong Shaoxi, Zhou Bingzhang, Wu Mingshun, Jin Weiliang, Liu Bin, Xue Huili, Cheng Caiyuan, Li Xiang, Luo Wankang, Yang Weijun, Hu Qiugu, Wang Fenglai, He Jiangang, Zhang Xingfu, Zhao Chengwen, Huang Jing, Wang Qinglin, Liu Lixin, Xie Lili, Liu Ming, Xiao Xiaosong, Qin Shihong, Lei Bo, Jiang Kai, Yu Zuguo, Xiong Lihong, Hou Ruxin, Yue Zengguo, Guo Zhanggen
Chief examiners: Zhou Fulin, Sun Weimin, Ma Jianxun, Wang Cungui, You Shiqi, Chen Zhengxiang, Zhang Youliang, Zhang Jingjie, Gu Xianglin
Contents
1 General Provisions 1
2 Terms and Symbols 1
2.1 Terms 1
2.2 Symbols 5
3 Materials 8
3.1 Strength Class of Materials 8
3.2 Calculation Data of Masonry 9
4 Basic Rules on Design 14
4.1 Principles of Design 14
4.2 Stipulations for Static Calculation of Buildings 16
4.3 Rules on Durability 20
5 Unreinforced Masonry Members 22
5.1 Compression Members 22
5.2 Local Compression 24
5.3 Members Subjected to Axial Tensile Load 28
5.4 Members Subjected to Bending 28
5.5 Members Subjected to Shear 29
6 Detailing Requirements 29
6.1 Verification for Slenderness Ratio of Wall and Column 29
6.2 General Detailing Requirements 31
6.3 Frame Filled Wall 34
6.4 Cavity Wall Filled with Insulation 35
6.5 Main Measures to Prevent Walls from Cracking 36
7 Ring Beams, Lintels, Wall Beams and Cantilever Beams 39
7.1 Ring Beams 39
7.2 Lintels 40
7.3 Wall Beams 41
7.4 Cantilever Beams 48
8 Reinforced Brick Masonry Members 51
8.1 Mesh-reinforced Brick Masonry Members 51
8.2 Composite Brick Masonry Members 52
9 Reinforced Concrete Masonry Members 58
9.1 General Requirements 58
9.2 Calculation of Reinforced Masonry Members Subjected to Axial Compression 58
9.3 Calculation of Reinforced Masonry Members Subjected to Shear 62
9.4 Detail Stipulation of Reinforced Concrete Masonry Shear Walls 64
10 Earthquake Resistance Design for Masonry Structure Members 68
10.1 General Requirements 68
10.2 Brick Masonry Members 75
10.3 Concrete Masonry Members 80
10.4 Earthquake Resistant Elements of Masonry Buildings with Bottom Frames 83
10.5 Earthquake Resistant Wall of Reinforced Concrete Masonry 88
Appendix A Specification and Dimension of Stone Materials and the Method for Defining the Strength Grades of Stone Materials 94
Appendix B Calculating Formulas for Strength Mean Values of Various Kinds of Masonry and Their Characteristic Strength Values 95
Appendix C Statical Calculation of "Semi-rigid" Buildings 98
Appendix D Influence Coefficients ψ and ψn 99
Explanation of Wording in This Code 106
List of Quoted Standards 107
1 General Provisions
1.0.1 This code is formulated with a view to implementing the technical and economic policies of the nation, persisting in wall material innovation, adjusting measures to local conditions, using local materials, reasonably selecting structural scheme and masonry materials, and achieving advanced technology, safety and usability, economy and rationality and quality guarantee.
1.0.2 This code is applicable to the design of the following masonry structures in building engineering, and the design for special conditions or with specific requirements shall be carried out according to special requirements:
1 Brick masonry: including unreinforced and reinforced masonry of fired common brick, fired perforated brick, autoclaved sand-lime brick, autoclaved flyash-lime brick, common concrete brick and perforated concrete brick;
2 Block masonry: including unreinforced and reinforced masonry of concrete block and light aggregate concrete block;
3 Stone masonry: including masonry of various squared stones and rubbles.
1.0.3 This code is established according to the principle specified in the current national standard "Unified Standard Reliability Design of Building Structures" GB 50068. The design terms and symbols are adopted according to the requirements of the current national standard "Standard for Terminology and Symbols Used in Design of Building Structures" GB/T 50083.
1.0.4 For design according to this code, the load shall comply with the current national standard "Load Code for the Design of Building Structures" GB 50009; the selection and application of wall materials shall comply with the current national standard "Uniform Technical Code for Wall Material used in Buildings" GB 50574; the selection of concrete materials shall meet the requirements of the current national standard "Code for Design of Concrete Structures" GB 50010; the construction quality control shall meet the requirements of the current national standards "Code for Acceptance of Constructional Quality of Masonry Structures" GB 50203 and "Code for Acceptance of Constructional Quality of Concrete Structures" GB 50204; and the structural earthquake resistance design shall meet the relevant requirements of the current national standard "Code for Seismic Design of Buildings" GB 50011.
1.0.5 The masonry structure design shall not only comply with this code, but also those in the current relevant ones of the nation.
2 Terms and Symbols
2.1 Terms
2.1.1 Masonry structure
Structure that wall and column built with block and mortar are used as the main loaded members of the building. It is the general term of brick masonry, block masonry and stone masonry structure.
2.1.2 Reinforced masonry structure
Structure that the reinforced masonry is used as the main loaded member of the building. It is the general term of mesh-reinforced masonry column, horizontal reinforced masonry wall, brick masonry and reinforced concrete layer or composite masonry column (wall) of reinforced mortar layer, composite wall of brick masonry and structural reinforced concrete column and reinforced concrete masonry shear wall structure.
2.1.3 Reinforced concrete masonry shear wall structure
Building structure composed of reinforced concrete masonry shear wall bearing vertical and horizontal action and concrete floor and roof.
2.1.4 Fired common brick
Roasted solid brick which takes coal gangue, shale, flyash or clay as the major raw materials, including fired coal gangue brick, fired shale brick, fired flyash brick, fired clay brick, etc.
2.1.5 Fired perforated brick
Fired brick that takes coal gangue, shale, flyash or clay as the major raw materials, with void ratio not greater than 35%, with small and more holes, and is mainly used for bearing position.
2.1.6 Autoclaved sand-lime brick
Solid brick which takes limy materials such as lime and siliceous materials such as sand as the major raw materials and is formed through blank preparation, pressing exhaust forming and autoclave curing.
2.1.7 Autoclaved flyash-lime brick
Solid brick which takes limy materials such as lime, slaked lime (carbide slag) or cement and siliceous materials such as flyash as well as aggregates (sand, etc.) as the major raw materials, adds an adequate amount of gypsum, and is formed through blank preparation, pressing exhaust forming and autoclave curing.
2.1.8 Concrete small hollow block
Hollow block which is made of ordinary concrete or light aggregate concrete, with a main dimension of 390mm×190mm×190mm and hollow ratio of 25%~50%, referred to as concrete block or masonry block.
2.1.9 Concrete brick
A perforated concrete half blind hole brick or solid brick which takes cement as cementitious material and sand, stone, etc. as the main aggregates and is made through mixing with water, forming and curing. The main dimensions of perforated bricks are 240mm×115mm×90mmm, 240mm×190mm×90mm, 190mm×190mmm×90mm, etc.; the main dimensions of solid bricks are 240mm×115mm×53mm, 240mm×115mm×90mm, etc.
2.1.10 Mortar for concrete small hollow block
Masonry mortar which is made by mechanically mixing such compositions as cement, sand, water and admixtures and additives added as required according to a certain proportion and is exclusively used for building concrete block, referred to as mortar for masonry block.
2.1.11 Grout for concrete small hollow block
Concrete which is made by mechanically mixing such compositions as cement, aggregate, water and admixtures and additives added as required according to a certain proportion and is used for concreting block masonry core column or other holes to be filled, referred to as block grout concrete.
2.1.12 Mortar for autoclaved silicate brick
Mortar which is made by mechanically mixing such compositions as cement, sand, water and admixtures and additives added as required according to a certain proportion and is exclusively used for building autoclaved lime-sand brick or autoclaved flyash brick masonry and the masonry shear strength shall not be less than the value of fired common brick masonry.
2.1.13 Pilastered wall
Buttressed wall which is formed by locally thickening the wall along the wall length direction at a certain interval.
2.1.14 Structural concrete column
Concrete column which is made according to the construction sequence of wall building first and then concrete column pouring based on structural reinforcement in the specified position of masonry building wall. Generally, it is referred to as structural concrete column, and structural column for short.
2.1.15 Ring beam
Sealed concrete beam member according to structural reinforcement, arranged along the horizontal direction of masonry wall at building eave, window top, storey, crane beam top or foundation top elevation.
2.1.16 Wall beam
Combined member composed of reinforced concrete joist and masonry wall within the range of calculation height on the beam, including simply-supported wall beam, continuous wall beam and frame-supported wall beam.
2.1.17 Cantilever beam
Cantilever reinforced concrete beam which is embedded in masonry. It general refers to balcony cantilever beam, awning cantilever beam or veranda cantilever beam in the building.
2.1.18 Design working life
Period specified in the design. During this period, the structure or structural member only needs normal maintenance for use according to its preset purpose, without overhaul reinforcement.
2.1.19 Static analysis scheme of building
Static analysis diagram of structure determined according to the space working performance of building. The static analysis scheme of building covers rigid analysis scheme, rigid-elastic analysis scheme and elastic analysis scheme.
2.1.20 Rigid analysis scheme
Static analysis scheme made for wall and column according to floor and roof as horizontally fixed hinged support.
2.1.21 Rigid-elastic analysis scheme
Static analysis scheme made for wall and column according to floor, roof and wall and column as hinged connection and in consideration of space working bent frame or frame.
2.1.22 Elastic analysis scheme
Scheme of static analysis for wall and column according to floor, roof and wall and column as hinged connection and without consideration of space working plane bent frame or frame.
2.1.23 Upper flexible and lower rigid complex multistorey building
Multistorey building that the top storey fails to meet the rigid analysis scheme requirements but the lower storeys meet the rigid analysis scheme requirements in structural analysis.
2.1.24 Types of roof or floor structure
Classification of roof and floor according to the structure detailing and corresponding rigidity of roof and floor. According to the common structure, the roof and floor may be divided into three types, but the horizontal rigidity of each type of roof and floor is approximately same.
2.1.25 Ratio of height to sectional thickness of wall or column
Ratio of calculation height to specified thickness of masonry wall and column. The specified thickness shall take the wall thickness for wall and the corresponding side length for column, and the sectional converted thickness for pilastered wall.
2.1.26 Effective support length of beam end
Distribution length of compressive stress of beam end on masonry or rigid cushion block interface along bean span direction.
2.1.27 Calculating overturning point
Rotating center taken as required for verifying the cantilever beam overturning resistance.
2.1.28 Expansion and contraction joint
Vertical joint with free expansion and contraction after the building is divided into two or several independent units, generally including double-wall expansion and contraction joint, double-column expansion and contraction joint, etc.
2.1.29 Control joint
Joint that the wall is divided into several independent wall limbs, and the wall limb is allowed with free deformation in its plane and has adequate resistivity against external force.
2.1.30 Category of construction quality control
Masonry construction quality control category divided according to quality assurance system of construction site, mortar and concrete strength, and comprehensive level of technical grade of masonry worker.
2.1.31 Confined masonry member
Masonry member which has restraint action by respectively arranging structural reinforced concrete column and ring-beam on both sides and upper and lower positions of unreinforced masonry wall piece for the purpose of increasing the ductility and resistance of unreinforced masonry wall piece.
2.1.32 Infilled wall in concrete frame structure
Wall which is built in frame structure.
2.1.33 Cavity wall filled with insulation
Wall that the continuous cavity reserved in the wall is filled with thermal insulating or heat insulating material and antirust metal tie is used to connect between interior side and exterior side of the wall.
2.1.34 Adjustable tie
Tie which is embedded in mortar joint of interior and exterior side of cavity wall filled with insulation and utilizes adjustable behavior to eliminate adverse effect generated by inconsistency of vertical deformation for interior and exterior side.
2.2 Symbols
2.2.1 Material property
MU——Strength class of block;
M——Strength class of common mortar;
Mb——Strength class of mortar for concrete small hollow block;
Ms——Strength class of mortar for autoclaved silicate brick;
C——Concrete strength class;
Cb——Strength class of grout for concrete small hollow block;
f1——Compressive strength class value or mean value of block;
f2——Compressive strength mean value of mortar;
f and fk——Design value and characteristic value of compressive strength of masonry;
fg——Design value of compressive strength of single-row hole and perforated concrete block grout masonry (referred to as design value of compressive strength of grout masonry);
fvg——Design value of shear strength of single-row hole and perforated concrete block grout masonry (referred to as design value of shear strength of grout masonry);
ft and ft,k——Design value and characteristic value of axial tensile strength of masonry;
ftm and ftm,k——Design value and characteristic value of bending tensile strength of masonry;
fv and fv,k——Design value and characteristic value of shear strength of masonry;
fVE——Design value of earthquake resistance shear strength damaged along the stepped section of masonry;
fn——Design value of compressive strength of mesh-reinforced brick masonry;
fy and ——Design value of tensile and compressive strength of steel bar;
fc——Design value of axial compressive strength of concrete;
E——Elastic modulus of masonry;
Ec——Elastic modulus of concrete;
G——Shear modulus of masonry.
2.2.2 Action and action effect
N——Design value of axial force;
Nl——Design value of axial force on local compression area and bearing pressure of beam end;
N0——Design value of upper axial force;
Nt——Design value of axial tension;
M——Design value of bending moment;
Mr——Design value of anti-overturning moment of cantilever beam;
Mov——Design value of overturning moment of cantilever beam;
V——Design value of shear force;
F1——Design value of concentrated load on top of joist;
Q1——Design value of evenly distributed load on top of joist;
Q2——Design value of evenly distributed load on top of wall beam;
σ0——Mean compressive stress of horizontal section.
2.2.3 Geometric parameters
A——Sectional area;
Ab——Area of cushion block;
Ac——Sectional area of structural concrete column;
Al——Local compression zone;
An——Clear sectional area of wall;
A0——Calculation area affecting local compressive strength;
As and ——Sectional area of tensioned and compressed steer bar;
a——Actual support length distance of side length and beam end;
ai——Distance from opening side to the nearest support center of wall beam;
a0——Effective support length of beam end;
as and ——Distance from center of gravity of longitudinal tensioned and compressed steer bar to the proximal edge of cross section;
b——Sectional width and side length;
bc——Width of structural concrete column along wall length direction;
bf——Calculated sectional flange width of pilastered wall and calculated width of wing wall;
——Flange calculation width of T-shaped and inverse L-shaped sectional compression zone;
bs——Door and window opening width within the distance range between adjacent transverse wall and wall between windows or between wall columns;
c and d——Distance;
e——Eccentricity of axial force;
H——Wall height and member height;
Hi——Storey height;
H0——Calculation height of member and calculation height of wall beam midspan section;
h——Wall thickness, smaller side length of rectangular section, side length along eccentric axial force direction of rectangular section, sectional height;
hb——Joist height;
h0——Effective height of section and converted height of cushion girder;
hT——Converted thickness of T-shaped section;
hw——Wall height and calculated sectional height of wall for wall beam;
l——Spacing between structural columns;
l0——Calculation span of beam;
ln——Clear span of beam;
I——Sectional moment of inertia;
i——Gyration radius of section;
s——Spacing and sectional moment of area;
x0——Distance between calculating overturning point and outer edge of wall;
umax——Maximum horizontal displacement;
W——Section resistance moment;
y——Distance from section gravity center to section edge of axial force in eccentric direction;
z——Internal force arm.
2.2.4 Calculation coefficient
α——Ratio of grout concrete area in block masonry to gross area of masonry, correction coefficient and coefficient;
αM——Bending moment coefficient of joist in consideration of the combination action of wall beam;
β——Slenderness ratio of member;
[β]——Allowable slenderness ratio of wall and column;
βV——Shear coefficient of joist in consideration of the combination action of wall beam;
γ——Improvement coefficient of local compressive strength of masonry, coefficient;
γa——Adjustment coefficient;
γf——Partial coefficient of structural member property;
γ0——Significance coefficient of structure;
γG——Partial coefficient of permanent load;
γRE——Earthquake resistance adjustment coefficient of bearing capacity;
δ——Void ratio of concrete block, coefficient;
ζ——Local compressive coefficient of masonry at the upper part of joist support;
ζc——Participation service coefficient of core column;
ζs——Participation service coefficient of steel bar;
ηi——Influence coefficient of space property of building;
ηc——Restraint correction coefficient of wall;
ηN——Joist midspan axial force coefficient in consideration of the combination action of wall beam;
λ——Shear-span ratio of calculation section;
μ——Correction coefficient, influence coefficient of composite shear and compressive force;
μ1——Correction coefficient of allowable slenderness ratio of self-bearing wall;
μ2——Correction coefficient of allowable slenderness ratio of wall with door and window opening;
μc——Improvement coefficient of allowable slenderness ratio of wall arranged with structural column;
ξ——Relative height of sectional compression zone, coefficient;
ξb——Limit of relative height of compression zone;
ξ1——Influence coefficient of wing wall or structural column to shear bearing capacity of wall for wall beam;
ξ2——Influence coefficient of opening to shear bearing capacity of wall for wall beam;
ρ——Ratio of grouting and ratio of reinforcement of concrete masonry;
ρs——Horizontal steel bar area ratio calculated according to vertical section of interlayer wall;
φ——Influence coefficient of bearing capacity, coefficient;
φn——Influence coefficient of bearing capacity of mesh-reinforced brick masonry member;
φ0——Stability coefficient of axial compression member;
φcom——Stability coefficient of composite brick masonry member;
ψ——Reduction coefficient;
ψM——Influence coefficient of opening to joist bending moment.
3 Materials
3.1 Strength Class of Materials
3.1.1 The strength class of bearing structure block shall be adopted according to the following requirements:
1 Strength class of fired common brick and fired perforated brick: MU30, MU25, MU20, MU15 and MU10;
2 Strength class of autoclaved sand-lime brick and autoclaved flyash-lime brick: MU25, MU20 and MU15;
3 Strength class of common concrete brick and perforated concrete brick: MU30, MU25, MU20 and MU15;
4 Strength class of concrete block and light aggregate concrete block: MU20, MU15, MU10, MU7.5 and MU5;
5 Strength class of stone: MU100, MU80, MU60, MU50, MU40, MU30 and MU20.
Notes: 1 The void ratio of light aggregate concrete block masonry with double-row hole or multi-row hole for bearing shall not be greater than 35%;
2 The folding-pressure ratio limit of perforated brick and autoclaved siliceous brick for bearing, the limit of void ratio, wall and rib dimension of perforated brick of non-sintered material for bearing as well as the carbonization and softening performance requirements shall meet the relevant requirements of the current national standard "Uniform Technical Code for Wall Material used in Buildings" GB 50574;
3 The specification, dimension and strength class of stone may be determined in accordance with the method in Appendix A of this code.
3.1.2 The strength class of hollow brick and light aggregate concrete block of the self-bearing wall shall be adopted according to the following requirements:
1 Strength class of hollow brick: MU10, MU7.5, MU5 and MU3.5;
2 Strength class of light aggregate concrete block: MU10, MU7.5, MU5 and MU3.5.
3.1.3 The strength class of mortar shall be adopted according to the following requirements:
1 Strength class of common mortar adopted by fired common brick, fired perforated brick, autoclaved sand-lime brick and autoclaved flyash-lime brick: M15, M10, M7.5, M5 and M2.5; strength class of dedicated masonry mortar adopted by autoclaved sand-lime brick and autoclaved flyash-lime brick masonry: Ms15, Ms10, Ms7.5 and Ms5.0;
2 Strength class of mortar adopted by common concrete brick, perforated concrete brick, concrete block with single-row hole and gangue concrete block masonry: Mb20, Mb15, Mb10, Mb7.5 and Mb5;
3 Strength class of mortar adopted by light aggregate concrete block masonry with double-row hole or multi-row hole: Mb10, Mb7.5 and Mb5;
4 Strength class of mortar adopted by untrimmed squared stone and rubble masonry: M7.5, M5 and M2.5.
Note: In determination of strength class of mortar, the block of the same kind shall be adopted as the bottom formwork of test block for mortar strength.
Contents of GB 50003-2011
1 General Provisions
2 Terms and Symbols
2.1 Terms
2.2 Symbols
3 Materials
3.1 Strength Class of Materials
3.2 Calculation Data of Masonry
4 Basic Rules on Design
4.1 Principles of Design
4.2 Stipulations for Static Calculation of Buildings
4.3 Rules on Durability
5 Unreinforced Masonry Members
5.1 Compression Members
5.2 Local Compression
5.3 Members Subjected to Axial Tensile Load
5.4 Members Subjected to Bending
5.5 Members Subjected to Shear
6 Detailing Requirements
6.1 Verification for Slenderness Ratio of Wall and Column
6.2 General Detailing Requirements
6.3 Frame Filled Wall
6.4 Cavity Wall Filled with Insulation
6.5 Main Measures to Prevent Walls from Cracking
7 Ring Beams, Lintels, Wall Beams and Cantilever Beams
7.1 Ring Beams
7.2 Lintels
7.3 Wall Beams
7.4 Cantilever Beams
8 Reinforced Brick Masonry Members
8.1 Mesh-reinforced Brick Masonry Members
8.2 Composite Brick Masonry Members
9 Reinforced Concrete Masonry Members
9.1 General Requirements
9.2 Calculation of Reinforced Masonry Members Subjected to Axial Compression
9.3 Calculation of Reinforced Masonry Members Subjected to Shear
9.4 Detail Stipulation of Reinforced Concrete Masonry Shear Walls
10 Earthquake Resistance Design for Masonry Structure Members
10.1 General Requirements
10.2 Brick Masonry Members
10.3 Concrete Masonry Members
10.4 Earthquake Resistant Elements of Masonry Buildings with Bottom Frames
10.5 Earthquake Resistant Wall of Reinforced Concrete Masonry
Appendix A Specification and Dimension of Stone Materials and the Method for Defining the Strength Grades of Stone Materials
Appendix B Calculating Formulas for Strength Mean Values of Various Kinds of Masonry and Their Characteristic Strength Values
Appendix C Statical Calculation of "Semi-rigid" Buildings
Appendix D Influence Coefficients ψ and ψn
Explanation of Wording in This Code
List of Quoted Standards
