M 180 SPECIFICATIONS FOR MATERIALS
Standard Specification for
Corrugated Sheet Steel Beams for Highway Guardrail
AASHTO DESIGNATION: M 180-89
1. SCOPE Type IV-Beams of corrosion resistant the fabricator. For acceptance of a brand,
steel. the fabricator shall furnish, a Brand
3.1.2 Classes: Registration and Guarantee meeting the
1.1 This specification covers corrugated approval of the Engineer and showing the
sheet steel prepared for use as beams in Class A-Base metal nominal thick- brand name or designation, the manner in
highway guardrails. ness-2.67 mm (0.105 in.). which it will appear on the fabricated
1.2 The values stated in SI units are to be Class B-Base metal nominal thick- beams, the typical mechanical properties,
regarded as the standard. ness-3.43 mm (0.135 in.). chemical composition if specified, the
class and type of guardrail, and other
specified properties. The fabricator shall
2. REFERENCED DOCUMENTS 4. ORDERING INFORMATION
also guarantee that as long as material is
furnished under that brand and
2.1 AASHTO Standards: 4.1 Orders for guardrail under this designation, it will conform fully to the
M 120 Zinc Metal (Slab Zinc) specification shall include the following requirements of the specification and
information, as required, to adequately shall be replaced without cost to the
M 232 Zinc Coating (Hot Dip) on describe the desired material: Engineer when found not in conformity
Iron and Steel Hardware with any of the specified requirements.
4.1.1 Quantity (linear meter or number
M 298 Coatings of Zinc of pieces), The Brand Registration and Guarantee
Mechanically Deposited on shall be sworn to for the fabricator by a
Iron and Steel 4.1.2 Class of Guardrail, person having legal authority to bind the
T 65 Mass of Coating on Zinc- 4.1.3 Type of Guardrail, company. Upon approval of a Brand
Coated (Galvanized) Iron or 4.1.4 Effective length of beam section Registration and Guarantee, that brand
Steel Articles 3.8 or 7.6 m (12.5 ft or 25.0 ft), will be accepted without further
certification. If, in subsequent actual field
2.2 ASTM Standards: 4.1.5 Shape (W-Beam or Thrie Beam),
use, there is evidence of misbranding as
A 307 Carbon Steel Externally and
determined by random sampling and
Threaded Standard Fasteners 4.1.6 Exceptions to this specification, detection of inadequate tensile strength,
A 525 General Requirements for or special requirements, if any. yield strength, elongation, improper
Steel Sheet, Zinc-Coated coating, deficient thickness or improper
(Galvanized) by the Hot-Dip 5. BASIS OF ACCEPTANCE fabrication, the material will be rejected
Process and approval for further use withdrawn
E 376 Recommended Practice for until subsequently reapproved. Samples
Measuring Coating Thickness 5.1 All material shall be subject to for test of any material offered for use
by Magnetic-Field or Eddy- inspection and sampling at the fabricating may be taken at any time deemed
Current (Electromagnetic) plant, warehouse, or after delivery to the desirable by the engineer.
Test Methods site of construction. 5.3.2 The manufacturer or fabricator
2.3 Federal Standards: 5.2 Acceptance by Sampling: shall make such tests and measurements
5.2.1 The Engineer may take one piece as necessary to insure that the material
TT P-641 Primer, Paint, Zinc Dust- produced complies with all specification
Zinc Oxide (For galvanized of guardrail, a backup plate, and end or
buffer section from each 200 pieces in a requirements. These tests and
surfaces) measurements shall be so identified by
lot, or from each lot if less than 200
2.4 Military Standards: pieces are included therein, for the identification symbols or code used
DOD-P-21035 Paint, High Zinc Dust determination of compliance with on the beam that the manufacturer can
Content, Galvanizing Repair specification requirements. If one piece produce specific reports showing these
(Metric) fails to meet, two other pieces shall be test results. Copies of reports of these
tested. If either of these pieces fail to tests shall be kept on file and shall be
conform to the requirements of this submitted to the engineer upon request.
3. CLASSIFICATION specification, the lot of material 5.3.3 The brand shall be removed or
represented by these samples shall be obliterated by the manufacturer or
3.1 Four types and two classes of rejected. A lot shall be considered that fabricator on all material where control
guardrail are provided as follows: quantity of material offered for tests, as outlined herein, do not show
inspection at one time which bears the conformance to this specification.
3.1.1 Types:
same heat and coating identification.
Type I-Zinc coated, 550 g/m2 (1.80
5.3 Acceptance by Brand Registration
oz/ft2) minimum single-spot. 6. MATERIALS
and Guarantee:
Type II-Zinc coated, 1100 g/m2 (3.60
5.3.1 By mutual agreement between
oz/ft2) minimum single-spot. 6.1 Base Metal-The beam, transition, end
the fabricator and Engineer, acceptance
Type III-Beams to be painted. may be based upon a Brand Registration and buffer sections shall consist of sheet
and Guarantee filed with the Engineer by made of open hearth, electric furnace or
188
M 180 SPECIFICATIONS FOR MATERIALS
basic oxygen steel and shall meet the conformance with the requirements 9.1.3 The sheets or beams shall be of
mechanical properties specified in shown in Figures 1 and 2. Transition prime finish, that is, free from injurious
Section 8. The chemical composition of sections shall be fabricated in accordance defects such as blisters, flux, and
the base metal for Type IV beams shall with Figure 4 and shall provide a smooth uncoated spots. Uncoated edges resulting
be as approved by the engineer. and uniform transition between beams. from shearing or punching will not be
6.2 Zinc-The zinc used for the coating of They shall be ready for assembly when considered objectionable.
Type I and II sections shall be as delivered. Only drilling or cutting 9.1.4 The coating shall be smooth, free
prescribed in M 120, and shall be at least necessary for special connections and for of beading or sharp projections along the
equal to the grade designated as "Prime sampling will be permitted in the field. edges and shall adhere tenaciously to the
Western." Warped or deformed beams will be surface of the metal. The adherence of
rejected. Beams to be erected on a radius the zinc coating to the surface of the base
6.3 Bolts and Nuts: of 46 m (150 ft) or less shall be shop metal shall be determined by cutting or
6.3.1 Unless otherwise specified, bolts curved to the appropriate curvature of the prying with a stout knife, applied with
and nuts for Types I, II, and III beams installation. considerable pressure in a manner
shall conform to or exceed the tending to remove a portion of the
requirements of ASTM A 307 and shall coating by paring or whittling, and it
be coated in accordance with Section 9.4. 8. MECHANICAL PROPERTIES
shall not be possible to peel any portion
6.3.2 Bolts and nuts for Type IV beams of the coating so as to expose the base
shall be of an approved corrosion resis- 8.1 The me chanical properties of the metal.
tant material and conform to or exceed base metal shall conform to the following 9.1.5 The test specimen size and
the requirements of ASTM A 307. requirements: method of tests for determining the mass
6.3.3 All connections or splices shall 8.1.1 Beams and transition sections: of coating shall be as prescribed in T 65.
be formed with oval shoulder button Yield Point, minimum, 345 MPa (50000 psi); At the option of the Engineer, material
headed bolts to minimize projections on Tensile Strength, minimum 483 MPa (70000 may be accepted on the basis of magnetic
the road side of the guardrail. Splice and psi); and gage determinations made in accordance
post bolts and nuts shall conform to one with ASTM E 376.
Elongation, in 50 mm (2 in.), minimum, 12
of the configurations shown in Figure 3. percent. 9.2 Type III Beams:
Either of the alternate configurations may
be furnished unless otherwise specified 8.1.2 End and buffer sections: 9.2.1 Beams which are to be painted
by the engineer. Yield Point, minimum, 227 MPa (33000 psi); shall be cleaned and shop painted with
and one coat of rust-inhibitive primer. The
6.4 Washers and Backup Plates: primer shall have a tough and durable
Tensile Strength, minimum 310 MPa (45000
6.4.1 Washers shall be rectangular as psi). surface and shall be thoroughly dry
shown in Figure 1. Washers for Types 1, before the sheets are handled or packed
8.1.3 Test specimens for mechanical
II, and III beams shall be galvanized in for shipment.
properties shall be prepared and tested as
accordance with Section 9. Washers for
specified in ASTM A 525 except that 9.3 Type IV Beams:
Type IV beams, shall be of an approved
orrection for thickness of zinc coated 9.3.1 Beams of corrosion resistant steel
corrosion resistant steel. Backup plates if
specimens shall be 0.08 mm (0.003 in.) shall not be painted or galvanized. They
specified for use at nonsplice points shall
for Type I beam and 0.15 mm (0.006 in.) shall be so handled and stored that the
consist of 305-mm (1ft) sections of
for Type II beam. traffic face of these beams, used in a
beams and shall be of the same Class and
Type specified for the full length beams. continuous run of guardrail, shall not
9. COATING REQUIREMENTS show a distinctive color differential.
6.5 End or Buffer Sections:
9.4 Bolts and Nuts:
6.5.1 End or buffer sections shall be of
the same or greater thickness of metal 9.1 Type I and II Beams: 9.4.1 Bolts and nuts shall be hot-dip
and the same type as the beam to which it zinc coated in accordance with the
9.1.1 The beams may be galvanized requirements of M 232, Class C or
is attached or the engineer may specify before or after fabrication.
the minimum thickness of metal and mechanically zinc coated in accordance
type. 9.1.2 The mass of coating shall with M 298, Class 50, Type 1.
conform to the requirements prescribed 9.5 Washers:
in Table 2 for the types specified. The
7. MANUFACTURE mass of coating is the total amount of 9.5.1 Washers shall be hot-dip zinc
galvanizing on both sides of a sheet or coated in accordance with the
beam, expressed as grams per square requirements of M 232.
7.1 The beams and end or buffer sections
meter (oz/ft2) of sheet.
shall be shaped and, punched in
TABLE 1
Beam or Sheet Thickness
TABLE 2
Class A Class B
Weight of Coating
Tolerance Under Specified Tolerance Under Specified
Type Type Min Check Limit Min Check Limit
Thickness Thickness. No Limit for Thickness Thickness, No Limit for
Single-Spot Test Triple-Spot Test
Over Thickness Over Thickness
g/m2 oz/ft3 g/m2 oz/ft2
mm in min in mm in mm in
I... 550 1.80 610 2.00
I... 2.74 0.108 0.23 0.009 3.51 0.138 0.25 0.010
II.. 1100 3.60 1220 4.00
II ... 2.82 0.111 0.23 0.009 3.58 0.141 0.25 0.010
III... 2.67 0.105 0.23 0.009 3.43 0.135 0.25 0.010
IV ... 2.67 0.105 0.23 0.009 3.43 0.135 0.25 0.010
189
M 180 SPECIFICATIONS FOR MATERIALS
FIGURE 1
190
M 180 SPECIFICATIONS FOR MATERIALS
FIGURE 2
191
M 180 SPECIFICATIONS FOR MATERIALS
192
M 180 SPECIFICATIONS FOR MATERIALS
193
M 180 SPECIFICATIONS FOR MATERIALS
9.6 Galvanizing Repair: widths of 483 mm (19 in.) for W -Beams Number and Coating Lot, AASHTO
and 749 mm (29 ½ in.) for Thrie Beams. Specification Number, and Class and Type.
9.6.1 Where the galvanizing on
guardrail or fittings has been damaged, Tolerance from the nominal width of 11.2 Markings shall not be placed at
the coating shall be repaired by minus 3.2 mm (⅛ in.) will be such a location that they will be obscured
regalvanizing or the surface repaired by permissible. after erection, or in a manner that the
painting with two coats of zinc dust-zinc NOTE-The requirements of paragraph 10.2.1
brand will be conspicuous to any traffic.
oxide paint conforming to Federal are intended to define the minimum width Markings placed on the traffic face of the
Specification 17-P-641 or DOD-P-21035. sheet permissible. Calculation of exact width beam shall be placed in the valley of the
dimensions from Figures 1 and 2 shows that center corrugation and shall be die
the finished product may slightly exceed these inprinted with letters and numerals not
10. DIMENSIONS widths. However, the dimensions of Figures 1 exceeding 13 mm (½ in.) in height.
and 2 can be met within allowable tolerance by
using the nominal widths. Use of sheets 11.3 Marking material shall be such as
10.1 Sheet or Beam Thickness: slightly greater than the nominal widths is to resist obliteration during storage,
10.1.1 The nominal thickness for the permissible provided the tolerances in Figures transportation, and erection.
finished beam or sheet shall conform to 1 and 2 are met. 11.4 Markings for end sections and
the requirements as prescribed in Table 1. backup plates may be on durable tags
10.1.2 For fabricated beams, thickness 11. MARKING securely attached to each section or
measurements will be made on tangent bundle except that when specified by the
portions of the cross section. engineer, each individual piece shall be
11.1 Each beam element shall be marked.
10.2 Sheet Width: identified by the following:
10.2.1 The beam elements shall be Name or Brand of Manufacturer, Identification
formed from sheets having nominal Symbols or Code for Heat
194
