AASHTO MP 18M/MP 18-15涵盖了无涂层、耐腐蚀、变形和普通铬合金的钢坯混凝土钢筋和切割长度或卷制的传力杆，其中耐腐蚀性能可能至关重要。变形钢筋的标准尺寸和尺寸及其编号应为表2中列出的毫米-千克钢筋[表3中列出的英寸-磅钢筋]。注1——对于变形钢筋卷，工业设备的容量限制了可矫直的最大钢筋尺寸。注2——钢筋或传力杆所需的耐腐蚀程度取决于项目的环境条件和嵌入钢筋或传力杆的混凝土。钢筋有三个最低屈服水平:420 MPa[60000 psi]、520 MPa[75000 psi]和690 MPa[100000 psi]，分别指定为420级[60]、520级[75]和690级[100]。 热轧普通圆，尺寸小于等于50 mm[2 in.]当规定销钉、螺旋、结构连接件或支撑件的直径为线圈或切割长度时，应根据本规范提供420[60]、520[75]和690[100]级的延性性能，最接近标称直径的变形钢筋尺寸的试验规定应适用。规定变形和标记的要求不适用。注3:小于10毫米[3/8英寸]的普通圆的重量直径应根据ASTM A510/A510M中的尺寸计算。注4:当需要焊接本规范中列出的材料时，应符合AWS D1的要求。4结构焊接规范——钢筋和AWS D1的适用章节。6结构焊接规范-不锈钢。如果这些规范中未提及材料，则应联系钢材制造商，以获得特定应用的焊接程序。 本规范适用于国际单位制（如规范MP 18M）或英制单位（如规范MP 18）的订单。国际单位制和英寸磅单位不一定相等。为清晰起见，文本中的括号中显示了英寸-磅单位，但它们是订购MP 18材料时的适用值。

AASHTO MP 18M/MP 18-15 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. The standard sizes and dimensions of deformed bars and their number designations shall be those listed in Table 2 for millimeter-kilogram bars [Table 3 for 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]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 - 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.