ITEM 608.54 - DETECTABLE WARNING DEVICES, CAST IRON
A.
SCOPE
This work shall consist of furnishing and installing a detectable warning surface, concrete
sidewalk pad and tip-down ramp, and accessories at locations shown on the plans, as
specified herein, or as ordered including any and all required surface preparation.
MATERIALS AND CONSTRUCTION
Detectable warnings shall be installed at sidewalk ramps where a sidewalk crosses a
public vehicular way, excluding unsignalized driveway crossings. Detectable warnings
shall measure 24” in the direction of travel and extend the full width of the sidewalk ramp
and the edge nearest the curb line shall be located 6 to 8” from the face of curb line.
Detectable warnings shall consist of a surface of truncated domes and shall comply with
section 705 of the ADA and ABA Guidelines for Buildings and Facilities. Truncated
domes in a detectable warning surface shall have a base diameter of 0.9 inch (23 mm)
minimum and 1.4 inches (36 mm) maximum, a top diameter of 50 percent of the base
diameter minimum to 65 percent of the base diameter maximum, and a height of 0.2 inch
(5.1 mm). Truncated domes shall have a center-to-center spacing of 1.6 inches (41 mm)
minimum and 2.4 inches (61 mm) maximum, and a base-to-base spacing of 0.65 inch (17
mm) minimum, measured between the most adjacent domes on a square grid. Detectable
warning surfaces shall be either natural patina or federal yellow cast iron as directed by
the engineer. The detectable warning shall be placed on a Portland cement concrete
sidewalk pad.
Tap Alamerer of
ce 6o a of the base diameter ', =
. ‘ 0.2
base diameter of a4
ec a i ek ol ———*""..: =)
O94 (23-56 mm) i
(8)
Bleweg icity Iu
fenlargect) plan
Figure 705.1 Size and Spacing of Truncated Domes
MEASUREMENT AND PAYMENT
This item shall be measured by the Square Yard of Detectable Warning Devices installed.
Payment for this item shall be at the contract unit price per Square Yard. This payment
shall also include all materials, labor, equipment, and all else needed to complete the
work under this item.
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