1 General Provisions
1.0.1 This specification was formulated to unify the technical requirements of the corrosion protection design, construction, inspection and maintenance of steel structures in sea port construction, and control corrosion protection engineering quality.
1.0.2 This specification is applicable to the corrosion protection design, construction, inspection and maintenance of steel structures in sea port construction such as piling bar, trestle bridge and floating drum.
1.0.3 In addition to the requirements of this specification, the corrosion protection design, construction, inspection and maintenance of steel structures in sea port construction shall also meet the requirements of the current relevant standards of the nation.
2 Terms
2.0.1 Metallic corrosion
It refers to the physical-chemical interaction between metal and environment, which would change the metal performance, and often damages the functions of metal and environment or the technical system consisting of them.
2.0.2 Electrochemical corrosion
It refers to such corrosion that contains one kind of electrode reactions at least.
2.0.3 Corrosion rate
It refers to the value of metallic corrosion effect in unit time.
2.0.4 Corrosion allowance
It refers to the corresponding thickness added when the possible corrosion losses during usage period is taken into consideration in the design of metal members.
2.0.5 Galvanic corrosion
It refers to such corrosion caused by the action of corrosion cell.
2.0.6 Stray current
It refers to current streaming on the non-designated loop
2.0.7 Stray current corrosion
It refers to corrosion caused by stray current.
2.0.8 Corrosion current
It refers to the current intensity involving in electrode reaction, which directly causes corrosion.
2.0.9 Corrosion potential
It refers to the electrode potential of metal in given corrosion system.
2.0.10 Natural corrosion potential
It refers to the corrosion potential where there is no net current flowing in or out of the studied metal surface.
2.0.11 Protective potential scope
The interval of corrosion potential value required to make metal reach the required corrosion resistance for special purpose.
2.0.12 Protective potential
It refers to the critical value of corrosion potential which must be reached into order to enter protective potential scope.
2.0.13 Protective current density
It refers the polarizing current density required to maintain the potential of the protected object within the protective potential scope.
2.0.14 Cathodic protection
It refers to the electrochemical protection achieved by reducing corrosion potential
2.0.15 Sacrificial anode
It refers to the electrode bar which protects the cathode coupled with it by raising its corrosion rate.
2.0.16 Sacrificial anode cathodic protection
It refers to such cathodic protection provided protective current by the sacrificial anode coupled with the protected object.
2.0.17 Impressed current cathodic protection
It refers to such cathodic protection provided protective current by external power supply.
2.0.18 Protection efficiency
It refers to the percentage of specific type of corrosion rate reduced by taking corrosion protection measures.
2.0.19 Over protection
It refers to such ill-effect phenomenon caused by over negative polarization potential in cathodic protection.
2.0.20 Reference electrode
It refers to the electrode whose potential is stable and repeatable, and may be adopted as reference to measure other electrodes.
2.0.21 Anode shield
It refers to the insulating layer covered within certain area around auxiliary anode in impressed current cathodic protection system in order to distribute the output current of auxiliary anode to farther cathode surface with the purpose of making the potential of protective structure uniform.
2.0.22 Water resistance
It refers to the interfacial resistance of anode of cathodic protection system in water.
2.0.23 Open circuit potential
It refers to the natural corrosion potential of sacrificial anode in electrolyte solution.
2.0.24 Operating potential
It refers to the potential in the working state of sacrificial anode in electrolyte.
2.0.25 Driving voltage
It refers to the difference between sacrificial anode operating potential and the potntial of protected object.
2.0.26 Utilization factor of sacrificial anode
It refers to the ratio of consumption quality and original quality of anode where the sacrificial anode is used to the current insufficient to provide for the protected structure.
2.0.27 Theoretical capacitance
It refers to the electric quantity produced by anode consumption mass per unit calculated according to Faraday's law.
2.0.28 Actual capacitance
It refers to the electric quantity produced by actually-measured anode consumption mass per unit.
2.0.29 Surface pretreatment
It refers to such measure taken for the matrix surface by mechanical method or chemical method before application of paint in order to improve the binding force and corrosion protection effect between coat and matrix to meet the paint application requirements
2.0.30 Secondary derusting
It refers to the technology process of removing rust layer and other dirt again for the steel surface which has been derusted once and provided with maintenance primer or parkerized protection film to apply corrosion protective paint.
2.0.31 Derusting grade
It refers to the clean degree grade of attachment such as the rust layer on steel surface before application of paint.
2.0.32 Metal spraying
It refers to such technology process of using high-pressure air, inert gases or electric arc etc. to spray molten corrosion resistant metal to the surface of protected structure to form protective coat.
2.0.33 Coat
It refers to a kind of liquid or powder material containing with pigment. Where applied on substrate, it may form an opaque film with protection, finishing or specific functions.
2.0.34 Coating
It refers to the protective layer formed by using some kinds of paints by one-layer or multi-layer single coating operation.
2.0.35 Application of paint
It refers to the process of coating paints on matrix surface to form coat with protection, finishing or specific functions.
2.0.36 Adhesive force
It refers to the binding force between dry coating film and its substrate.
2.0.37 Weather resistance
It refers to the capacity of coating film resisting the effect of atmospheric environment.
2.0.38 Coating ageing
It refers the process of coating film occur fading, discoloring, crack, pulverization and peeling etc. due to the action of natural factors, which causes rust resistance disappear.
2.0.39 Pinhole
It refers to such phenomenon that coating film generates pinholes during coating drying process.
2.0.40 Coat defect
It refers to such defects as deficient hiding power, film stripping, pinhole, bubble, fracture and missing coating due to improper surface pretreatment, poor paint quality and application technology.
2.0.41 Cladding
It refers to such method of compounding a layer of corrosion resistant material on the structure external surface to isolate the original surface and the environment.
2.0.42 Wrapping
It refers to such method of winding ribbon-pattern corrosion resistant material such as plastics and rubber on the external surface of the metal members of pipe and pile etc. to isolate the original surface and the environment to prevent corrosion.
3 General Requirements
3.0.1 The steel structure must be carried out with corrosion protection design.
3.0.2 Corrosion protection measure shall be determined according to environmental conditions, material, structural type, operating requirements, construction conditions and maintenance management conditions etc.
3.0.3 The position division of steel structures in sea port construction shall meet the requirements of Table 3.0.3.
