Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: AASHTO MP 18M/MP 18:2015
• Năm ban hành / Publication date: 2015
• Tình trạng / Status: W - Hết hiệu lực
• Tên tiếng Anh / Title in English: Standard Specification for Uncoated, Corrosion-Resistant, Deformed and Plain Chromium Alloyed, Billet-Steel Bars for Concrete Reinforcement and Dowels
• Thay thế cho / Replace: AASHTO MP 18M/MP 18:2009
• Số trang / Page: 31

Phạm vi áp dụng / Scope of standard

This specification covers uncoated, corrosion-resistant,
deformed and plain chromium alloyed, billet-steel concrete
reinforcement and dowel bars in cut lengths or coils, where
corrosion-resistant performance may be essential (Notes 1 and 2).
The standard sizes and dimensions of deformed bars and their number
designations shall be those listed in Table 2 for
millimeter-kilogram bars [Table 3for inch-pound bars].

Note 1-For coils of deformed bars, the capacity
of industrial equipment limits the maximum bar size that can be
straightened.

Note 2-The degree of corrosion resistance
needed for reinforcement or dowel bars is dependent on both the
project's environmental conditions and the concrete in which they
are embedded.

Bars are of three minimum yield levels: 420 MPa [60,000 psi],
520 MPa [75,000 psi], and 690 MPa [100,000 psi], designated as
Grade 420 [60], Grade 520 [75], and Grade 690 [100],
respectively.

Hot-rolled plain rounds, in sizes up to and including 50 mm [2
in.] in diameter in coils or cut lengths, when specified for
dowels, spirals, and structural ties or supports, shall be
furnished under this specification in Grade 420 [60], Grade 520
[75], and Grade 690 [100] (Note 3).

For ductility properties, test provisions of the nearest nominal
diameter deformed bar size shall apply. Those requirements
providing for deformations and marking shall not be applicable
(Note 3).

Note 3-The weight for plain rounds smaller than
10 mm [3/8 in.] in diameter shall be computed on the basis of the
size in ASTM A510/A510M.

Note 4-When welding of the material listed in
this specification is required, it should be in conformance with
AWS D1.4 Structural Welding Code-Reinforcing Steel and the
applicable sections of AWS D1.6 Structural Welding Code-Stainless
Steels. If the material is not addressed in these specifications,
the manufacturer of the steel should be contacted to obtain a
welding procedure for the particular application. 

This specification is applicable for orders in either SI units
(as Specification MP 18M) or in inchpound units (as Specification
MP 18). SI units and inch-pound units are not necessarily
equivalent. Inch-pound units are shown in brackets in the text for
clarity, but they are the applicable values when the material is
ordered to MP 18.