1、Standard Specification for Uncoated, Corrosion-Resistant, Deformed and Plain Chromium Alloyed, Billet-Steel Bars for Concrete Reinforcement and Dowels AASHTO Designation: MP 18M/MP 18-151American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washi
2、ngton, D.C. 20001TS 4g MP 18M/MP 18-1 AASHTO Standard Specification for Uncoated, Corrosion-Resistant, Deformed and Plain Chromium Alloyed, Billet-Steel Bars for Concrete Reinforcement and Dowels AASHTO Designation: MP 18M/MP 18-1511. SCOPE 1.1. This specification covers uncoated, corrosion-resistan
3、t, 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
4、2 for millimeter-kilogram bars Table 3for inch-pound bars. Note 1For coils of deformed bars, the capacity of industrial equipment limits the maximum bar size that can be straightened. Note 2The degree of corrosion resistance needed for reinforcement or dowel bars is dependent on both the projects en
5、vironmental conditions and the concrete in which they are embedded. 1.2. 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. 1.3. Hot-rolled plain rounds, in sizes up to an
6、d 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 di
7、ameter deformed bar size shall apply. Those requirements providing for deformations and marking shall not be applicable (Note 3). Note 3The weight for plain rounds smaller than 10 mm 3/8in. in diameter shall be computed on the basis of the size in ASTM A510/A510M. Note 4When welding of the material
8、listed in this specification is required, it should be in conformance with AWS D1.4 Structural Welding CodeReinforcing Steel and the applicable sections of AWS D1.6 Structural Welding CodeStainless Steels. If the material is not addressed in these specifications, the manufacturer of the steel should
9、 be contacted to obtain a welding procedure for the particular application. 1.4. This specification is applicable for orders in either SI units (as Specification MP 18M) or in inch-pound units (as Specification MP 18). SI units and inch-pound units are not necessarily equivalent. Inch-pound units ar
10、e shown in brackets in the text for clarity, but they are the applicable values when the material is ordered to MP 18. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 4g MP 18M/MP 18-2 AASHTO 2. REFER
11、ENCED DOCUMENTS 2.1. AASHTO Standards: M 31M/M 31, Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement T 244, Mechanical Testing of Steel Products T 285, Bend Test for Bars for Concrete Reinforcement 2.2. ASTM Standards: A276/A276M, Standard Specification for Stainless Steel Bars and Sha
12、pes A484/A484M, Standard Specification for General Requirements for Stainless Steel Bars, Billets, and Forgings A510/A510M, Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Carbon Steel, and Alloy Steel A700, Standard Guide for Packaging, Marking, and Loading Meth
13、ods for Steel Products for Shipment A751, Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products A955/A955M, Standard Specification for Deformed and Plain Stainless-Steel Bars for Concrete Reinforcement A1035/A1035M, Standard Specification for Deformed and Plain, L
14、ow-Carbon, Chromium, Steel Bars for Concrete Reinforcement E29, Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications 2.3. Military Standards: MIL-STD-129, Marking for Shipment and Storage MIL-STD-163, Steel Mill Products Preparation for Shipment an
15、d Storage 2.4. Federal Standard: Fed. Std. No. 123, Marking for Shipment (Civil Agencies) 2.5. AWS Standards: AWS D1.4, Structural Welding CodeReinforcing Steel AWS D1.6, Structural Welding CodeStainless Steels 3. TERMINOLOGY 3.1. Description of Terms Specific to This Standard: 3.1.1. corrosion-resi
16、stanta relative term indicating resistance to the several forms of corrosion in various environments or corroding media, often compared to the resistance of uncoated plain carbon steels in the same environment or media. 3.1.2. deformed barsteel bar with protrusions; a bar that is intended for use as
17、 reinforcement in reinforced concrete construction. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 4g MP 18M/MP 18-3 AASHTO 3.1.2.1. DiscussionThe surface of the bar is provided with lugs or protrusi
18、ons that inhibit longitudinal movement of the bar relative to the concrete surrounding the bar in such construction. The lugs or protrusions conform to the provisions of this specification. 3.1.3. deformationsprotrusions on a deformed bar. 3.1.4. plain barsteel bar without protrusions. 3.1.5. riblon
19、gitudinal protrusion on a deformed bar. 3.1.6. lotbars of one bar number, heat number, and pattern of deformation contained in an individual shipping release or shipping order. 3.1.7. heata batch of steel produced to meet specified physical and chemical properties. A unique heat number is assigned b
20、y the manufacturer to identify each batch of steel. 3.1.8. Uncoated Corrosion Resistant Reinforcement (CRR)concrete reinforcing bar materials, because of their chemical composition and or microstructure, provide enhanced corrosion resistance properties. 4. ORDERING INFORMATION 4.1. Orders for deform
21、ed or plain chromium-alloyed steel billet-steel bars for concrete reinforcement under this specification should include the following information: 4.1.1. Quantity (Mass) weight; 4.1.2. UNS number of the alloy, Type or Common Name (see Table 1); 4.1.3. Size (diameter) or bar designation number (see T
22、able 2 for mm-kg bars or Table 3 for in-lb bars); 4.1.4. Cut length or coils; 4.1.5. Deformed or plain; 4.1.6. Grade; 4.1.7. Packaging (see Section 22); and 4.1.8. AASHTO designation and year of issue. 4.2. The purchaser shall have the option to specify additional requirements, including but not lim
23、ited to, the following: 4.2.1. Certified mill test reports; 4.2.2. Comparative corrosion performance data in accordance with Supplemental Annex A only when specified in the purchase order; 4.2.3. Special bar markings; 4.2.4. Other special requirements, if any. Note 5A typical ordering description is
24、 as follows: 10 tonnes, uncoated, corrosion-resistant, deformed and plain chromium-alloyed, billet-steel bars for concrete reinforcement and dowels, 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 4g
25、MP 18M/MP 18-4 AASHTO UNS S31653, No. 25, 18-m long, deformed, Grade 520, in secured lifts, to MP 18M-_. Certified mill test reports are required. 10 tons, uncoated, corrosion-resistant, deformed and plain chromium-alloyed, billet-steel bars for concrete reinforcement and dowels, UNS S31653, No. 8,
26、60 ft 0 in. long, deformed, Grade 75 in secured lifts, to MP 18-_. Certified mill test reports are required. 5. MATERIALS AND MANUFACTURE 5.1. The bars shall be rolled from properly identified heats of mold cast or strand cast steel using any commercially accepted steelmaking process. 6. CHEMICAL RE
27、QUIREMENTS 6.1. The chemical analysis of each heat shall be determined in accordance with ASTM A751. The manufacturer shall make the analysis on test samples taken preferably during the pouring of the heat. The percentages of carbon, chromium, copper, manganese, molybdenum, nickel, nitrogen, phospho
28、rus, silicon, sulfur, and vanadium shall be determined and reported as required in Section 20. 6.2. The analysis of the heat shall be made by the manufacturer and shall conform to the analysis tolerances specified in Table 1 of ASTM A484/A484M when compared to the chemistry reported in Annex A2, Sec
29、tion A2.6.3. 6.2.1. A product check made by the purchaser shall conform to the analysis tolerances specified in Table 1 of ASTM A484/A484M when compared to the chemistry reported in Annex A2, Section A2.6.3. 6.3. The chemical composition as shown by heat analysis shall meet the requirements shown in
30、 Table 1. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.Table 1Selected Compositional Requirements for Iron-Based, Chromium, and Chromium-Nickel Reinforcing BarsaUNS Designation Type or Common Name Com
31、position, %bCarbon (C) Manganese (Mn) Chromium (Cr) Nickel (Ni) Molybdenum (Mo) Nitrogen (N) Other Elements Austenitic Stainless Steels S24000 XM-29 0.08 11.5014.50 17.019.0 2.33.7 0.200.40 S24100 XM-28 0.15 11.0014.00 16.519.0 0.502.50 0.200.45 S30400 304 0.08 2.00 18.020.0 8.011.0 S30453 304LN 0.0
32、30 2.00 18.020.0 8.011.0 0.100.16 S31603 316L 0.030 2.00 16.018.0 10.014.0 2.003.00 S31653 316LN 0.030 2.00 16.018.0 10.013.0 2.003.00 0.100.16 Duplex (Austenitic-Ferritic) Stainless Steels S31803 2205 0.030 2.00 21.023.0 4.56.5 2.53.5 0.080.20 S32101 0.040 4.06.0 21.022.0 1.351.70 0.100.80 0.200.25
33、 Cu: 0.100.80 S32205 2205 0.030 2.00 22.023.0 4.56.5 3.03.5 0.140.20 S32304 2304 0.030 2.50 21.524.5 3.05.5 0.050.60 0.050.20 Cu: 0.050.60 Patented Dual-Phase Alloyed SteelscDuracorr 0.025 1.50 11.012.5 1.00 0.200.35 0.030 MMFX2d0.15 2.0 9.2 (Minimum) 0.20 aUnlisted elements are governed by ASTM A27
34、6/A276M for Austenitic and Duplex stainless steel products listed in Table 1. bSingle values are maximum weight percentages except where noted. cThese alloys have a single producer. dMeet the requirements of ASTM A1035/A1035M. TS-4gMP18M/MP18-5 AASHTO 2015 by the American Association of State Highwa
35、y and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 4g MP 18M/MP 18-6 AASHTO 7. REQUIREMENTS FOR DEFORMATIONS 7.1. Deformations shall be spaced along the bar at substantially uniform distances. The deformations on opposite sides of the bar shall be sim
36、ilar in size, shape, and pattern. 7.2. The deformations shall be placed with respect to the axis of the bar so that the included angle is not less than 45 degrees. Where the line of deformations forms an included angle with the axis of the bar from 45 to 70 degrees inclusive, the deformations shall
37、alternately reverse in direction on each side, or those on one side shall be reversed in direction from those on the opposite side. Where the line of deformation is greater than 70 degrees, a reversal in direction is not required. 7.3. The average spacing or distance between deformations on each sid
38、e of the bar shall not exceed seven tenths of the nominal diameter of the bar. 7.4. The overall length of deformations shall be such that the gap between the ends of the deformations on opposite sides of the bar shall not exceed 12.5 percent of the nominal perimeter of the bar. Where the ends termin
39、ate in a longitudinal rib, the width of the longitudinal rib shall be considered the gap. Where more than two longitudinal ribs are involved, the total width of all longitudinal ribs shall not exceed 25 percent of the nominal perimeter of the bar; furthermore, the summation of gaps shall not exceed
40、25 percent of the nominal perimeter of the bar. The nominal perimeter of the bar shall be 3.14 times the nominal diameter. 7.5. The spacing, height, and gap of deformations shall conform to the requirements prescribed in Table 2 Table 3. Table 2Deformed Bar Designation Numbers, Nominal Masses, Nomin
41、al Dimensions, and Deformation Requirements, SI Units Bar Designation No.aNominal Mass, kg/m Nominal DimensionsbDeformation Requirements, mm Diameter, mm Cross-Sectional Area, mm2Perimeter, mm Maximum Average Spacing Minimum Average Height Maximum Gap (Chord of 12.5% of Nominal Perimeter) 10 0.560 9
42、.5 71 29.9 6.7 0.38 3.6 13 0.994 12.7 129 39.9 8.9 0.51 4.9 16 1.552 15.9 199 49.9 11.1 0.71 6.1 19 2.235 19.1 284 59.8 13.3 0.97 7.3 22 3.042 22.2 387 69.8 15.5 1.12 8.5 25 3.973 25.4 510 79.8 17.8 1.27 9.7 29 5.060 28.7 645 90.0 20.1 1.42 10.9 32 6.404 32.3 819 101.3 22.6 1.63 12.4 36 7.907 35.8 1
43、006 112.5 25.1 1.80 13.7 43 11.38 43.0 1452 135.1 30.1 2.16 16.5 57 20.24 57.3 2581 180.1 40.1 2.59 21.9 aBar numbers approximate the number of millimeters of the nominal diameter of the bar. bThe nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same mass
44、per meter as the deformed bar. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 4g MP 18M/MP 18-7 AASHTO Table 3Deformed Bar Designation Numbers, Nominal Weights, Nominal Dimensions, and Deformation Re
45、quirements, U.S. Customary Units Bar Designation No.aNominal Weight, lb/ft Nominal DimensionsbDeformation Requirements, in. Diameter, in. Cross-Sectional Area, in.2Perimeter, in. Maximum Average Spacing Minimum Average Height Maximum Gap (Chord of 12.5% of Nominal Perimeter) 3 0.376 0.375 0.11 1.178
46、 0.262 0.015 0.143 4 0.668 0.500 0.20 1.571 0.350 0.020 0.191 5 1.043 0.625 0.31 1.963 0.437 0.028 0.239 6 1.502 0.750 0.44 2.356 0.525 0.038 0.286 7 2.044 0.875 0.60 2.749 0.612 0.044 0.334 8 2.670 1.000 0.79 3.142 0.700 0.050 0.383 9 3.400 1.128 1.00 3.544 0.790 0.056 0.431 10 4.303 1.270 1.27 3.9
47、90 0.889 0.064 0.487 11 5.313 1.410 1.56 4.430 0.987 0.071 0.540 14 7.65 1.693 2.25 5.32 1.185 0.085 0.648 18 13.60 2.257 4.00 7.09 1.58 0.102 0.864 aBar numbers are based on the number of eighths of an inch included in the nominal diameter of the bars. bThe nominal dimensions of a deformed bar are
48、equivalent to those of a plain round bar having the same weight per foot as the deformed bar. 8. MEASUREMENTS OF DEFORMATIONS 8.1. The average spacing of deformations shall be determined by measuring the length of a minimum of ten spaces and dividing that length by the number of spaces included in t
49、he measurement. The measurement shall begin from a point on a deformation at the beginning of the first space to a corresponding point on a deformation after the last included space. Spacing measurements shall not be made over a bar area containing bar marking symbols involving letters or numbers. 8.2. The average height of deformations shall be determined from measurements made on not fewer than two typical deformations. Determinations shall be bas
