【正文】 of nonprincipal load bearing members is C20, their protection layer thickness shall be those specified values for C25 in the table。④ The protection layer thickness for distributed rebars in plates, walls and shells shall be no less than 10mm。 the protection layer thickness for stirrups in beams and columns and for structural reinforcement shall be no less than 15mm。⑤ The protection layer thickness shall be increased as appropriate for important buildings with long service period and load bearing structures of buildings subject to erosion by coastal environment when they are in outdoor or high humidity indoor environment. When the strength of longitudinal tensile reinforcement is made full use of in the calculation, its anchoring length shall not be less than the minimum anchoring length as specified in Table .Min. anchoring length of longitudinal tensile reinforcement la (mm) Table Type of reinforcementConcrete strength gradeC15C20C25C30≥40Grade I rebar40d30d25d20d20dGrade II rebar50d40d35d30d25dGrade III rebar—45d40d35d30dColdrolled rebar with rib—40d35d30d25dCold drawn low carbon wire250Notes: ① For crescent ribbed reinforcement with a diameter d25mm, the anchoring length shall be increased by 5d from the values in the table。② The anchoring length of reinforcement subject to load should be increased as appropriate when the concrete is likely to be disturbed during the setting (. sliding form construction)。③ The anchoring length of longitudinal tensile Grade I, II and III reinforcement shall be no less than 250mm. The longitudinal tensile coldrolled reinforcement with ribs shall be no less than 200mm. Hooks shall be made at the ends of the smooth rebars subject to load in reinforcement skeletons. For nonprestressed load bearing reinforcement in tied skeletons and tied meshes, when the joints are made by splicing without welding: the splicing length of tensile reinforcement shall be no less than , and not less than 300mm。 and the splicing length of pressive reinforcement shall be no less than , and not less than 200mm.Nonwelding spliced joint can be used for connections in the load bearing direction in a welded skeleton, the splicing length of tensile reinforcement shall be no less than la, and the splicing length of pressive reinforcement shall be no less than . Within the nonwelded spliced joint length scope in a tied skeleton, the spacing between the stirrups shall be no greater than 5d and not greater than 100mm when the spliced reinforcement is subject to tensile load, and shall be no greater than 10d and not greater than 200mm when the spliced reinforcement is subject to pressive load. d is the minimum diameter in the load bearing reinforcement. The reinforcing ratio for the longitudinal load bearing reinforcement in a concrete member shall be no less than the values in Table .Min. reinforcing ratio for the longitudinal load bearing reinforcementin a concrete member (%) Table CategoryConcrete strength grade≤C35C40~C60All pressed rebars in a member subject to axial center pressionCompressed rebars in eccentrically pressed or eccentrically tensiled membersTensile rebars in bending member, eccentrically pressed member, major eccentrically tensile member, and tensile rebars on each side of minor eccentrically tensile memberNotes: ① The minimum reinforcing ratio of pressed reinforcement and tensile reinforcement in eccentrically pressed members shall be calculated for the whole sectional area of the member。 the minimum reinforcing ratio of all other tensile reinforcement shall be calculated for the sectional area after deducting the area of pressed edges or the edge with less tensile from the whole sectional area (b162。f – b)h162。f,② For prestressed concrete members containing carbon steel wires, indented steel wires, strand steel wires, heat treated rebars and cold drawn low carbon wires, the design value of normal sectional bearing capacity shall be no less than the internal force value when the normal section cracks open. For prestressed concrete bending members with above reinforcement, the normal sectional bending bearing capacity shall ply with the following requirements:Mu≥McrWhere Mu is the design value of normal sectional bending bearing capacity of the prestressed concrete bending member, and Mcr the normal sectional cracking bending moment value of the prestressed bending member。③ When such factors as temperature and shrinkage will produce significant influence on the structure, the minimum reinforcing ratio of the members shall be increased as appropriate. The longitudinal load bearing rebars at the lower portion of a simply supported plate shall extend into the abutment, with the anchoring length las no less than 5d. When reinforcement is achieved with welded mesh, at least one transversal rebar at the end shall be located within the edge of the abutment。 when this requirement cannot be met, the end of the load bearing rebar shall be made into a hook, or be welded with an additional transversal anchoring rebar.Note: When V, there shall be no less than two transversal anchoring rebars in the edge of the abutment, with a diameter no less than half of the diameter of longitudinal load bearing rebars. The lower longitudinal load bearing rebar of reinforced concrete simply supported beam shall have an anchoring length las extending into the scope of the abutment of the beam, which shall ply with the following conditions:I. When V≤: las≥5dII. When V: for rebars with crescent thread las≥12d for smooth rebars las≥15dIf the anchoring length of longitudinal load bearing rebars extending into the abutment of the beam does not ply with the above provision, effective anchoring measures shall be taken, such as welding transversal anchoring bars or anchoring steel plates on the reinforcement, or welding the end of t