GB/T 33240-2016 PDF English

GB/T33240-2016 (GBT33240-2016): PDF in English

GB/T 33240-2016 NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 77.140.60 H 44 Zinc-aluminum Alloy-epoxy Duplex Coated Steel Bars for the Reinforcement of Concrete ISSUED ON: DECEMBER 13, 2016 IMPLEMENTED ON: SEPTEMBER 01, 2017 Issued by: General Administration of Quality Supervision, Inspection and Quarantine; Standardization Administration of the People's Republic of China. Table of Contents Foreword ... 3  1 Scope ... 4  2 Normative references ... 4  3 Terms and definitions ... 5  4 Code and example ... 5  5 Ordering content ... 5  6 Technical Requirements ... 6  7 Test method ... 8  8 Test rules ... 10  9 Packaging, marking, quality certificate, transport and storage ... 10  Appendix A (Normative) Cathodic dis-bonding test ... 12  Foreword This Standard was drafted in accordance with the rules given in GB/T 1.1-2009. This Standard was proposed by China Iron and Steel Industry Association. This Standard shall be under the jurisdiction of National Technical Committee 183 on Iron and Steel of Standardization Administration of China (SAC/TC 183). The drafting organizations of this Standard: Xiamen New Steel Metal Products Co., Ltd., Fujian Provincial Sansteel (Group) Co., Ltd., Xiamen BFD Roads and Bridges New Technology Co., Ltd., China Metallurgical Information and Standardization Institute, Fujian Haixi Protection New Materials Joint Research Institute Co., Ltd., Xiamen Xinning Steel Co., Ltd., Xiamen Baoxinda New Energy Technology Co., Ltd. The drafters of this Standard: Zheng Yufei, Liu Jianfeng, Zheng Xu, Liu Baoshi, Zheng Yu, Wang Yujie, Zheng Jingjing, Zheng Juanjuan. Zinc-aluminum Alloy-epoxy Duplex Coated Steel Bars for the Reinforcement of Concrete 1 Scope This Standard specifies the terms and definitions, classification and code, order content, technical requirements, test methods, inspection rules, packaging, marking, quality certificate, transport and storage of zinc-aluminum alloy-epoxy duplex coated steel bars. This Standard applies to zinc-aluminum alloy-epoxy duplex coated steel bars and reinforced round bars for the reinforcement of concrete (hereinafter referred to as steel bars). The zinc-aluminum alloy coating shall be produced by continuous hot dip coating; the epoxy coating shall be produced by electrostatic spraying. 2 Normative references The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest edition (including all amendments) applies to this document. GB/T 470, Zinc ingots GB 1499.1, Steel for the reinforcement of concrete. Part 1: Hot rolled plain bars GB 1499.2, Steel for the reinforcement of concrete. Part 2: Hot rolled ribbed bars GB/T 2101, General requirement of acceptance, packaging, marking and certification for section steel GB/T 4956, Non-magnetic coatings on magnetic substrates - Measurement of coating thickness - Magnetic method GB/T 25826, Epoxy-coated steel for the reinforcement of concrete GB/T 50152, Standard for test method of concrete structures GB/T 32968, Zinc-aluminum alloy coated steel bars for the reinforcement of concrete YB/T 081, Rule for rounding off of numeric values and judgment of testing values for technical standards of metallurgy YS/T 310, Zinc alloy ingot for hot dip galvanizing 3 Terms and definitions Terms and definitions determined by GB/T 32968, GB/T 25826 and the following ones are applicable to this document. 3.1 Duplex coating On the clean metal surface, firstly perform continuous hot dipping zinc- aluminum alloy; then, coat a coating that is obtained from epoxy resin. 3.2 Fusion-bonded epoxy coating Spray on a heated clean metal surface in powder form to form a continuous coating after curing. The coating contains a thermosetting epoxy resin, a curing agent, a pigment, and other additives. 4 Code and example 4.1 Code The duplex coating steel is coded as ZEDR (the first letters of the words of Zinc- aluminum, Epoxy, Duplex, Reinforcement). 4.2 Model and example The model of the duplex coating steel consists of the code number, the steel grade and the nominal diameter of the steel, and the plating grade. Example: For the duplex steel bar, of which the nominal diameter is 20 mm, the grade is HRB400 hot-rolled ribbed steel bar and the zinc-aluminum alloy coating, the level is level-B, its product model is “ZEDR·HRB400-20B”. 5 Ordering content Contracts which order under this Standard shall include the following main contents: a) product name; b) number of this Standard; c) product model; d) weight; e) length; f) repair material requirements; g) special requirements. 6 Technical Requirements 6.1 Materials 6.1.1 Steel bar The base material for making duplex coating steel bars shall meet the requirements of GB 1499.1 or GB 1499.2 or GB/T 32968 or other product standards that are proposed by the buyer. The surface of the base material of the steel bar shall not have burrs, sharp corners and other defects that affect the quality of the coating, and shall be free of oil, grease or paint. 6.1.2 Zinc-aluminum alloy ingot Zinc-aluminum alloy ingots shall comply with the requirements of YS/T 310. 6.1.3 Zinc ingot Zinc ingots shall comply with the provisions of GB/T 470. 6.1.4 Epoxy resin powder coating The coating that is formed by epoxy resin powder shall meet the requirements of GB/T 25826. 6.1.5 Repair materials The repair material of zinc-aluminum alloy coating shall comply with the provisions of GB/T 32968. The repair material of epoxy coating shall comply with the provisions of GB/T 25826. 6.2 Coating requirements 6.2.1 Appearance The surface of the zinc-aluminum alloy coating shall be uniform and continuous, and there shall be no defects such as leakage plating, zinc tumor, zinc thorn and slagging. After the epoxy coating is cured, the surface shall be flat, uniform in color, free of bubbles, cracks, shrinkage cavities, and other visible defects. 6.2.2 Coating thickness The thickness of the zinc-aluminum alloy coating shall meet the thickness requirements of grade-B or grade-C of GB/T 32968. The recorded value of the duplex coating thickness after curing shall have at least 95% of probability between 180 μm ~ 300 μm; the single recorded value must not be lower than 140 μm. The upper limit of the coating thickness is not applicable to the area where the damaged coating is repaired. For environments with higher requirements on corrosion resistance, the recorded value of the coating thickness after curing shall have at least 95% of probability between 220 μm ~ 400 μm; the single recorded value must not be lower than 180 μm. Note: the above coating thickness requirements do not include areas that are repaired due to coating defects or breakage. 6.2.3 Coating continuity The number of leaks per meter of the steel bar shall not exceed 3. 6.2.4 Coating flexibility The steel bar shall be tested for coating flexibility. After the sample is bent, the coating on the outer surface of the bending portion of the sample shall be free of visible cracks or peeling. 6.2.5 Coating adhesion The coating adhesion test of the steel bar shall be carried out by the cathodic dis-bonding test method. Before the test, the flexibility test shall be carried out in accordance with 6.2.4. When it is tested from the edge of the artificial defect hole, the average value of the maximum peeling distance of 95% of steel bars shall not exceed 7.5 mm. 6.3 Repair of coating damage The coating area that is repaired per meter of the steel bar shall not exceed 0.5% of the total area (excluding the cut). The damaged or cut part of the coating shall be repaired with a zinc-rich paint first, and then it shall be coated with an epoxy repair paint. Prior to repair, all rusts and contaminants on the damaged area shall be removed by appropriate methods. The thickness of the zinc-rich coating after repair shall be not less than 40 μm; the total thickness of the duplex coating shall be not less than 180 μm. The repair material of the damaged coating shall comply with the provisions of 6.1.5. 6.4 Duplex coating steel site construction application guide For the duplex coating steel site construction application guide, refer to GB/T 25826. 7 Test method 7.1 Inspection items 7.1.1 The inspection items, sampling method, sampling portion and test methods of each batch of steel bars shall comply with the requirements of Table 1. Table 1 -- Inspection items, sampling method, sampling portion and test methods Serial No. Inspection items a Sampling quantity / piece Sampling portion Test method 1 Total coating thickness 3 Different steel bars 7.3, GB/T 4956 2 Coating continuity 3 Different steel bars 7.4 3 Coating flexibility 3 Different steel bars 7.5 4 Coating adhesion 3 Different steel bars 7.6 5 Appearance Piece by piece - 7.2 a The mechanical properties, bending properties and anti-bending properties of the steel bars after plating shall meet the requirements of GB 1499.2 and GB 1499.1. These items shall be tested as necessary. 7.1.2 For chemical resistance, cathodic dis-bonding, salt spray test, chloride permeability, bond strength, wear resistance and impact test, perform type inspection only, that is, perform inspection only when there are major changes in raw materials, production processes and equipment and when new products are produced and suspended products are resumed. The bond strength test shall be in accordance with the relevant provisions of GB 50152; the bond strength of the steel bar shall not be less than 85% of the bond strength of the uncoated steel bar. The cathodic dis-bonding test is carried out in accordance with Appendix A. Chemical resistance, salt spray test, chloride permeability, wear resistance and impact test are carried out in accordance with the provis.......
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