1109GUIDE RAIL AND METAL MEDIAN BARRIER

1109.01RAILS—As shown on the Standard Drawings and as follows:

rails.

A709, Grade 36. Galvanize as specified in Section 1105.02(s) (AASHTO M 111). Shop form, when required, on curves having a radius of less than 150 feet, as follows:

• Notch flanges to form a curve with a series of chords of equal lengths not exceeding 18 inches (for radii from 0 to 20 feet), 3 feet for radii from 20 feet to 100 feet, and 6 1/4 feet for radii from 100 feet to 150 feet; cut notches to the proper angle and weld.

• Form so the midpoint of the chord is tangent to the curve.

• Mark to show the approximate radius of curvature.

1109.02TERMINAL SECTIONS—As shown on the Standard Drawings and as follows:

1109.03POSTS—As shown on the Standard Drawings and as follows:

Galvanize as specified in Section 1105.02(s) (AASHTO M 111). Stamp posts with lengths greater than 6 feet as shown on the Standard Drawings. Stamping of posts is required for projects let after April 14, 2023. Stamping of posts is optional for projects let on or before April 14, 2023.

conforming to ASTM A709, Grade 36. Galvanize as specified in Section 1105.02(s) (AASHTO M 111).

Label each wood item with lot or batch number, plant, place, and date of manufacture. Manufacture from timber having a minimum grade of 1,200 pounds per square inch according to the current standard grading and dressing rules of the West Coast Lumber Inspection Bureau, the Southern Pine Inspection Bureau or other acceptable timber associations. Timber to be either rough sawn (unplanned) or surfaced four sides (s4s) to the dimensions indicated. Size in the direction parallel to the axis of bolt holes to be within a tolerance of ±1/4 inch. Use one type of surface finish for posts and offset blocks in a continuous run of guide rail. Treat timber with a preservative according to AASHTO M 133, after end cuts are made and holes are drilled. Certify as specified in Section 106.03(b)3.

1109.04OFFSET BRACKETS—

specified in Section 106.03(b)3.

manufactured from timber having a minimum grade of 1,200 pounds per square inch according to the standard grading and dressing rules of the West Coast Lumber Inspection Bureau, the Southern Pine Inspection Bureau, or other acceptable timber associations. Treat timber with a preser vative according to AASHTO M 133, after cutting ends, drilling bolt holes and, if applicable, routing. Provide brackets with a ±1/4-inch dimension tolerance in the direction of the bolt hole.

Rail to Bridge Barrier Transitions as shown on the Standard Drawings.

and manufactured from a combination of either virgin or recycled wood, plastic, rubber, or other materials. Provide brackets with a ±1/4-inch dimension tolerance in the direction of the bolt hole.

1109.05MISCELLANEOUS MATERIAL—As shown on the Standard Drawings and as follows:

Galvanize as specified in Section 1105.02(s) (ASTM A153, or ASTM B695 and B696).

Galvanize base plates and hardware after fabrication, as specified in Section 1105.02(s) (AASHTO M 111). Do not punch, drill, grind, cut, or weld after galvanizing. Repair minor abrasions of galvanized surfaces with two coats of galvanizing paint.

Grade 36. Galvanize as specified in Section 1105.02(s) (AASHTO M 111).

1109.06GALVANIZING —Galvanize metal parts as specifie d in Section 1105.02(s) (ASTM A 153 unless

otherwise specified) and conform to the requirements of AASHTO M 180, Section 9.

1109.07GALVANIZING PAINT—ASTM A780 Section 4.2.2

1109.08WELDING MATERIAL—Section 1105.02(t)

1109.09CERTIFICATION—Section 106.03(b)3