Detail of GB 50367-2006

Introduction of GB 50367-2006

1 General Provisions 1.0.1 This is formulated to enable concrete structure of strengthening of structure; achieve technical reliability, safety and usability, economy and rationality, guarantee quality. 1.0.2 This standard is applicable to building and construction reinforced concrete bearing structure strengthened design. 1.0.3 before concrete structure strengthening, reliability certification shall be made according to constructional variety, current national standard " Standard for appraisal of reliability of industrial buildings and structures" GB 50144 and "Standard for appraiser of reliability of civil buildings" GB 50292 .Where connecting with aseismic strengthening, seismic resistant capability appraisal shall be carried out yet in accordance with current national standard " "Code for Seismic Design of Buildings" GB 50011 or "Standard for Seismic Appraisal of Buildings" " GB 50023. 1.0.4 Concrete structure reinforced design, in addition to comply with this code provisions outside, shall also meet the provisions stated in current related national standards of requirements. 2 Terms, symbols 2.1 Terms 2.1.1 Strengthening of existing structures Measures concerning bearing structure, component, relevant portion, reinforcement , local replacement or internal force adjustment to improve fiduciary level and reliability or meet the owner's requirements. So safety, durability and applicability can be improved. 2.1.2 Existing structure member Existing component before strengthening. 2.1.3 Important structure member Supporting member, whose self failure would influence or endanger bearing structure system integrity. 2.1.4 General structure member Supporting member whose self failure is isolate incident and would not influence or endanger bearing structure system integrity. 2.1.5 Structure member strengthening with reinforced concrete Strengthening to increase existing structure member sectional area or increase reinforcement in order to improve bearing capacity, stiffness, rigidity or modify natural frequency of vibration. 2.1.6 Structure member strengthening with externally bonded steel frame Welding structure and grouting structural adhesive to reinforced concrete girder , column external bonded profiled bar and flat bars to bear the load and restrain existing structure members. 2.1.7 Structure member strengthening with externally bonded reinforced materials Adopt structural adhesive cementation, high tensile polymer mortar spray to make the reinforcing material stick to the concrete surface of existing structure member, to form integrity recombination cross section , bearing capacity and ductility. According to different reinforcing materials, it can be divided into outer adhered profiled bar, outer dead burning board, outer adhered fiber reinforced composites and steel wire rope meshes -polymer mortar layer. 2.1.8 Compression member confined by reinforcing wire Strengthening method to wind annealed wire and restrain strengthened compression component concrete so as to improve ultimate bearing resistance and ductility. 2.1.9 Structure member strengthening with externally applied pre-stressing Indirect strengthening method to improve existing structure, component load by applying outer pre-stress. 2.1.10 Bonded rebars Use special structural adhesive to anchor rib steel or full lighted type screw into base metal. 2.1.11 Structrual adhesives Adhesive bearing structure component, long term design stress and environmental agent for short structural adhesion. 2.1.12 Fibre reinforced ploymer (FRP) Composite material processed with adhesive dipping, cementation and solidification with fiber reinforcement effect by using regularly arranged high strength continuous fiber. 2.1.13 Polymer mortar High strength cement mortar mixed with modified epoxy emulsion or other modified copolymer emulsion. Except for improving physical mechanic performance, the polymer mortar used for bearing structure shall be able to notably improve anchored reinforcement and cementation. 2.1.14 Effective cross-section area Section deducting hole, wane, rust layer , regolith , weakened and failed part. 2.1.15 Design working life for strengthening of existing structure or its member After structure member strengthening, there is no need for inspection and appraisal. 2.2 Symbols 2.2.1 Material property Es0--Elastic modulus of existing structure member; Es--New elastic modulus of reinforcement; Ea--New profiled bar modulus of elasticity; Esp--New steel plate modulus of elasticity; Ei--New fiber reinforced polymer modulus of elasticity; fc0--Design value of concrete axes compression strength of existing structure member; fy0, --Tensile, compressive strength design value of existing structure member; fy, --Tensile, compressive strength design value of new reinforcement; fa, --Tensile, compressive strength design value of new profiled bar; fsp, --Tensile, compressive strength design value of new steel plate; ff--Design value of tensile strength of new fiber composites; ff, v--Design value of fiber composites and concrete cohesive strength; fbd--Design value of cohesive strength of structural adhesive; fud--Design value of anchor bolt tensile strength; εf--Tensile strain design value of fiber composites; εfe--Effective tensile strain design value of fiber composites circumferential bundle. 2.2.2 Action effect and bearing capacity N--Axial force design value after structure member strengthening; M--Bending moment design value after structure member strengthening; V--Shear force design value after structure member strengthening; M0k--Existing initial bending moment standard value of flexural member checking section before strengthening; σs--New longitudinal reinforcement tension stress; σs0--Stress of longitudinal tension reinforcement or side with smaller compression of existing structure member; σa--Stress of new model steel tension limb or limb with small compression; εf0--Delayed strain of fiber composites; ω--Component deflection or pre-stress invert arch. 2.2.3 Geometric parameter h0, h01--Effective height of section before and after structure member strengthening; hw--Web plate depth of component section; h0--Replacement depth of concrete in compressive area; hsp--Vertical height of beam side stick steel hoop board; hf--Vertical height of beam side stick fiber hoop board; hef--Effective anchor depth of anchor bolt; As0, --Tensile area, compressive area reinforcing steel area of existing structure member; As, --Tensile area, compressive area reinforcing steel area of existing component; Afe--Effective cross-section area of fiber composites; Acor--Concrete sectional area within circumferential enclosure bundle; Asp, --Sectional area of new tension steel plate and compressive steel plate; Aa, --Sectional area of new model steel tension limb, pressure limb; ls--Basic anchor depth of bonded rears; ld--Bonded rebar anchor depth design value; ll--Bonded rebar tension overlapping length; D--Diameter of drilling hole; 2.2.4 Calculation coefficients α1--Ratio between compressive area concrete rectangular stress pattern stress value and concrete axes compression strength design value; βc--Concrete compressive strength influence coefficient; β1--Ratio between rectangular stress pattern compressive area height and neutral axis height; αc--New concrete compressive strength utilization coefficient; αs--New reinforcement strength utilization coefficient; αa--New model steel strength utilization coefficient; αsp--Quoted calculation coefficients avoiding concrete split; ψ--Reduction coefficient, correction coefficient or influence coefficient; η--Enhancement coefficient or improvement coefficient. 3 Basic requirements 3.1 General provisions 3.1.1 After reliability certification, if the concrete structure is strengthened. The strengthening design shall be made according to expert conclusion, entrusting party requirements , this standard and requirements by owner and be carried out by qualified specialized technical personnel. Strengthening design range can be confirmed according to isolated area or whole building, designated structure , component or connection. structure integrity shall be considered. 3.1.2 Concrete structure safety class after strengthening shall be in accordance with severity, structure significance and design working life for strengthening of existing structure or its member after structural damage. entrusting party and design party shall decide according to actual situation. 3.1.3 Concrete structure strengthening design shall joint with actual construction method; take effective measure to guarantee new component and component be reliable connected with the existing structure. The new section and existing section shall be adhered firmly to form integrity. Avoid influence on unreinforcement part , relevant structure , component and soil foundation. 3.1.4 Effective control countermeasures shall be made in strengthening design to avoid soil differential settlement caused by high temperature, high humidity , low temperature , freeze thawing, chemical corrosion vibration and temperature stress. strengthening shall be made according to the order in the design specification. 3.1.5 Concrete structure strengthening design shall consider technical economy effectiveness and avoiding unnecessary dismantle or replacement. 3.1.6 Corresponding temporary safety measures shall be proposed in strengthening design document to avoid incline, instability , oversize deformation or collapse. The construction organization must be enforced strictly.

Contents of GB 50367-2006

1 General Provisions 2 Terms, symbols 2.1 Terms 2.2 Symbols 3 Basic requirements 3.1 General provisions 3.2 Design calculation principles 3.3 Strengthening method and fitting technology 4 Material 4.1 Cement 4.2 Concrete 4.3 Steel and welding material 4.4 Fiber and fiber composites 4.5 Structure strengthening adhesive 4.6 Concrete cracking repairing material 4.7 Rust-resistance agent 5 Structure member strengthening with reinforced concrete 5.1 Design requirements 5.2 Calculation on strengthening right section of flexural member 5.3 Calculation on flexural member diagonal section strengthening 5.4 Calculation on strengthening right section of flexural member 5.5 Structure provisions 6 Replacing concrete strengthening method 6.1 Design specification 6.2 Strengthening calculation 6.3 Structure provisions 7 Structure member strengthening with externally pre-stressing 7.1 Design specification 7.2 Strengthening calculation 7.3 Structure Provisions 8 Structure Member Strengthening with Externally Bonded Steel Frame 8.1 Design requirements 8.2 Strengthening calculation 8.3 Structure provisions 9 Structure Member Strengthening with Bonded Fibre Reinforced Ploymer (FRP) 9.1 Design requirements 9.2 Calculation on normal section strengthening of flexural member 9.3 Calculation on diagonal section strengthening of flexural member 9.4 Calculation on normal section strengthening of compression member 9.5 Calculation on diagonal section strengthening of compression member 9.6 Calculation on large eccentric compression member strengthening 9.7 Calculation on normal section strengthening of tension member 9.8 Calculation on ductility strengthening of column 9.9 Structure provisions 10 Structure Member Strengthening with Bonded Steel Plate 10.1 Design requirements 10.2 Calculation on strengthening right section of flexural member 10.3 Calculation on Flexural Member Diagonal Section Strengthening 10.4 Calculation on Normal Section Strengthening of Large Eccentric Compression Components 10.5 Calculation on Strengthening Right Section of Tension Component 10.6 Structure Provisions 11 Structure Member Strengthening with Additional Supporting Points 11.1 Design Requirements 11.2 Strengthening Calculation 11.3 Structure Provisions 12 Bonded Rebars Technology 12.1 Design Requirements 12.2 Anchoring Calculation 12.3 Structure Provisions 13 Anchor Bolt Technology 13.1 Design Requirements 13.2 Checking and Calculation for the Bearing Force of Anchor Bolt Steel 13.3 Checking and Calculation for the Bearing Force of Base Material Concrete 13.4 Structure Provisions 14 Crack Repairing Technology 14.1 Design Requirements 14.2 Crack Repairing Requirements Appendix A Determination of Standard Values of Structural Load of the Existing Structures Annex B Requirements of Age Modification of the Existing Structural Concrete Rebound Value Annex C Main Mechanical Property of Fibrous Materials Annex D Measuring Method for Fibre Reinforced Ploymer Interlaminar Shear Strength D.1 Application Scope D.2 Specimen Mould D.3 Sample Preparation D.4 Specimen Making D.5 Test Conditions D.6 Test Procedures D.7 Test Results Annex E Field Test Method and Evaluation Standard of Binding Material Agglutinating Strengthening Materials and Pulling Cohesive Strength of Base Materials E.1 Application Scope E.2 Test Equipment E.3 Sampling Principle E.4 Specimen Preparation E.5 Test Procedures E.6 Test Results E.7 Evaluation of the Inspection Result Qualification Annex F Laboratory Test Method and Evaluation Standard of Binding Material Agglutinating Strengthening Materials and Pulling Cohesive Strength of Base Materials F.1 Application Scope F.2 Test Equipment F.3 Specimens F.4 Test Environment F.5 Test Procedures F.6 Test Results Annex G: Rich Filling Gel and Polymer Mortar Mass - Determination of Tensile Splitting Strength Annex H: determination for rupture strength of high strength polymer mortar mass Annex J determination for tensile shear strength rich filling cohesive material Annex K: Adhesive Bonding Under Restrain Drawing - Determination for Bond Strength of Steel Bar and Base Material Concrete Annex L Determination for Heat Aging Property of Structural Adhesive Annex M: Analytical Method of Anchor Bolt Connection Stress Annex N Field Inspection Method and Evaluation Standard of Anchor Bearing Capacity Annex P Steel Wire Rope Net - Structure Member Strengthening With Polymer Mortar External Layer Annex Q Compression Member Confined by Reinforcing Wire Annex R Rust Block Method for Reinforcement of Existing Concrete Structure Explanation of Wording in This Code