NATIONAL STANDARDSTCVN 8790:2011PAINT PROTECTION-STEEL STRUCTURE CONSTRUCTION PROCESS ANDProtective paint systems for steel and bridge structures-Procedures construction and acceptancePrefaceTCVN 8790:2011 is converted from 22TCN 253-98 according to the provisions in clause 1 of 69 Articles of law standards and technical regulation and art. 1 article 7 of decree 127/2007/ND-CP on 1/8/2008 detailing the Government's implementation of some articles of the law on technical regulation and standards.TCVN 8790:2011 by the Institute of science and technology of transportation, Ministry of transportation, General Directorate for standards and quality evaluation, the Ministry of science and technology announced.PAINT PROTECTION-STEEL STRUCTURE CONSTRUCTION PROCESS ANDProtective paint systems for steel and bridge structures-Procedures construction and acceptance1. scope of application1.1. This standard applies to the execution (by the method of spraying, rolling, scan), test, monitor the types of paint protection beams of steel bridges, steel building structure in tropical climate conditions (for the type of paint used) according to technical requirements to protect the traffic.1.2. All the paints used to protect steel and bridge steel structure anticorrosion guarantee with regard to the extent of erosion of the environment respectively.2. documents cited The document cited the following is needed to apply this standard. For the materials cited the record year of publication shall apply a stated. For the materials cited are not recorded in published the latest version shall apply, including the additional amendments (if any).TCVN 2092:2008 (ISO 2431:1993), paints and varnishes-determination of flow time by hopper flows.TCVN 2096:1993, painting-the method determines the dry time.TCVN 2097:1993, paint-methods for determining the adhesion of the coating membrane.ISO 8789:2011, painted steel structure protection-technical requirements and testing methods.ISO 2808, Paints and varnishes-Determination of film thickness (paints and varnishes-determination method of thickness).3. Terms and definitions 3.1. The paint (Paint or coating)A type of coating materials have color, usually in liquid, powder or paste, when scanned, roll or spray to the surface membrane can form the Government, have corrosion protection properties, decoration or other specific properties required by the work.3.2. the protective paint Systems (paint system)Collection of the coating by paints or related products was constructed up the steel surfaces form corrosion protection coating membrane.3.3. Primer (primer coating)The paint layer in direct contact with the surface to be painted.3.4. Painting (intermediate coating)The paint layer is located between priming and coating on the outside.3.5. Paint (top coats)The outermost layer of paint of a paint system, designed to protect the paint underneath from the influence of the environment, contributing to the overall corrosion protection of both the system and bring about the necessary colors.3.6. The thickness of dry coating membrane (Dry film thickness)The thickness of the paint layer left on the surface when it has dried completely.3.7. Working time (pot life)The maximum period of time that the paint many component use after the ingredients have been mixed together.4. Prepare the surface and material before painting4.1. The material4.1.1. The material tested according to the test method respectively. The sampling and sample processing must conform to the following provisions of the ISO 8789:2011.CAPTION 1: any target would not be included in the specifications of the coating material that can affect the conditions of implementation or the quality of the final work must be given by the manufacturer.4.1.2. The preservation of materialsPaint manufacturers need to specify the time limit for use of the material on each specific product. Coating materials must be stored at temperatures in the range from 3oC to 40oC, unless other regulations made under the instructions of the manufacturer. Particularly for coating materials of the water system may be froze when preserved in low temperature under 3 ºc.Coating materials and other related materials (solid substances, solvents ...) must be preserved in the airy place, away from sources of fire causing ...Product containers must ensure the sealed in the process of preservation. The barrel has a part must be sealed and marked carefully. They can be used if no indications in the technical data of the paint manufacturer.4.2. Surface preparation before coating construction4.2.1. Prepare the surface before the paint is the most important factor in the process of construction paints.Surface preparation process is the process of cleaning the dirt as soluble salts, rust, grease, dirt, water, steel rolling, old paint flakes cling loosely, creatures clinging dirt ... out of the steel surfaces with roughness for steel surfaces and increase the ability of membrane adhesion of paint.4.2.2. rusty steel surfaces of Degrees are classified into four levels as follows:+ Level A: steel surface has rusty legs but very little, make up pale yellow on the steel surface.+ Level B: steel surface corrosion and the spots began appearing Rusty Nail, creating a dark stain yellow spotting on the steel surface.+ C-level: steel surface has rust scales, can be warped, creating several small dents visible with the naked eye.+ Level D: steel surface has more rust scales, appears more small dent can be easily seen with the naked eye.4.2.3. The first of the surface preparation process is to proceed to wash grease from the surface of the steel. With the contaminated area is small, can be purged by the solvent (gasoline, kerosene) or phase-solvent paint.For an area of massive contamination, must use physical methods to break the contamination status then use the cleaning by the emulsion is the best and the last spray rinse with clean water.4.2.4. Nếu bề mặt bị nhiễm muối hòa tan do môi trường ô nhiễm hay được hình thành từ thép bị gỉ phải tiến hành rửa bề mặt thép bằng nước áp suất cao (áp suất nước ≥ 810,60 kPa), sau đó dùng khí khô để thổi khô bề mặt thép trước khi tiến hành các phương pháp làm sạch bề mặt khác.4.3. Các phương pháp làm sạch bề mặt 4.3.1. Làm sạch bằng phương pháp thủ công: bao gồm sử dụng bàn chải thép, máy mài hoặc các loại bàn chải khác. Phương pháp này được sử dụng để làm sạch những lớp gỉ nhỏ bám dính lỏng lẻo trên bề mặt thép với diện tích nhỏ hoặc những lớp sơn đã bị giảm chất lượng. Những vị trí khó thi công phải sử dụng phương pháp phun. Trước khi làm sạch bằng phương pháp thủ công, các lớp gỉ nặng phải được làm sạch bằng cách gõ, cạo từng lớp một, các lớp dầu mỡ bụi bẩn nhìn thấy được bằng mắt thường cũng phải được làm sạch.Làm sạch bằng phương pháp thủ công (St)Phương pháp St 1: không phù hợp với bề mặt chuẩn bị thi công sơn.Phương pháp St 2: Làm sạch hoàn toàn bằng dụng cụ sử dụng năng lượng và dụng cụ cầm tay.The surface to be cleaned off the grease, dust, slag, rust and old paint layers, strange objects stick sticking loosely to the surface. See the pictures B St2; C and D St2 St2-Appendix AThe method of St 3: clean very thoroughly by the energy tools and hand tools.Similar to St2 method, but in this case the surface is processed more, shiny surfaces result. See the pictures B St3; C and D St3 St3-Appendix A.4.3.2. Clean with abrasive drying method is the most common and most effective for cleaning the surface of the steel. The method is done by spraying of abrasive substances with high pressure onto the steel surface. Often used as a dry abrasive sand. Can replace metal sand or other substances such as steel, metal slag, metal grinding grain.4.3.2.1. Clean by blowing method (Sa)Clean the surface by blowing method is denoted by the letters "Sa".Before cleaning by blowing method, the heavy patina will be removed by conventional instruments. Chemical contamination can be seen such as oil, grease, dust, ... also need to remove.Sau khi sử dụng phương pháp thổi bề mặt sẽ làm sạch hết các chất bụi bẩn và mảnh vỡ xốp có trên đó.CHÚ THÍCH 2: Đối với các phương pháp chuẩn bị bề mặt bằng phương pháp thổi bao gồm cả quá trình xử lý bề mặt trước và sau khi tiến hành làm sạch bề mặt bằng phương pháp thổi.Làm sạch bằng phương pháp thổi bao gồm các phương pháp sau:4.3.2.2. Làm sạch bằng phương pháp thổi nhẹ (Sa1)Bề mặt được làm sạch hết các chất bụi bẩn, dầu, mỡ có thể thấy được bằng mắt thường; cũng như là xỉ, gỉ, sơn cũ và các chất lạ bám dính lỏng lẻo trên bề mặt.Xem các hình ảnh B. Sa 1; C. Sa1 và D Sa1 - Phụ lục A4.3.2.3. Làm sạch bằng phương pháp thổi vừa phải (Sa 2)Bề mặt được làm sạch hết các loại bụi bẩn, dầu mỡ, nhất là xỉ, gỉ, sơn cũ và các vật lạ. Phần còn lại của các chất nhiễm bẩn này sẽ dính bám vững chắc trên bề mặt. Xem hình ảnh B.Sa2; CSa2 và D. Sa2 - Phụ lục A.4.3.2.4. Làm sạch bằng phương pháp thổi mạnh (Sa 2 1/2).Bề mặt được loại bỏ hết dầu mỡ, bụi bẩn, xỉ, gỉ và các lớp sơn cũ cũng như các vật thể lạ. Những vết bẩn còn giữ lại trên bề mặt thư
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