721.01 Description. This item shall consist of furnishing and
installing raised pavement markers according to the se specifications and at the locations shown on the plans or as direc ted.
721.02 Materials. The markers shall conform to the shape and
dimensions shown on the plans. Pavement markers shall be of the type and color sho wn on the plans or as specified herein.
a.Type of Markers. Pavement markers shall be one of the following types: Type I - One-Way (Color) Reflective Markers Type II - Two-Way (Color/Color) Reflective Markers
b.Packaging and Storage. Pavement markers shall comply with the following packaging and storage requiremen ts.
1.Packaging. Each package shall be clearly marked as to the name of the manufacturer, type, color, quantity enclosed, lot number, and date of manufacture.
2.Storage. Markers shall be stored indoors and shall be protected from any source of moisture both during s hipment to the project site and at the project site. The mark ers shall be maintained at a temperature high enough to preclude moisture condensation, and, at the time of placement, both t he markers and their containers shall be dry.
c.Reflective Pavement Markers. Reflective pavement markers shall be one of the following types: • Prismatic reflector type, consisting of methyl meth acrylate (MM) or suitable compounded acrylonitrile butadiene styrene (ABS) shell filled with a mixture of an ine rt thermosetting compound and filler material. The ex terior surface of the shell shall be smooth and contain on e or two methyl methacrylate prismatic reflector faces with thin, untempered glass bonded to the faces to provide an extremely hard and durable abrasion-resistant surfa ce. The glass is not required on the red faces of two-way (Clear/Red) reflective markers. The infrared curve s of the compounded MM or ABS shells shall match approved curves on file in the Materials Division. • High performance microprismatic lens type, consisti ng of a polycarbonate lens with independent lens cells and a ceramer lens coating. The marker shall consist of hermetically sealed components in a fiber reinforce d polycarbonate body with finger grip indentations fo r ease of handling. The base of the marker shall be flat (the deviation from a flat surface shall not exceed 0.05" [1.3 mm]), rough tex tured, and free from gloss or substances that may reduce its bond t o the adhesive. Raised pavement markers shall meet the requirements of ASTM D 4280.
d.Adhesives.
1.Epoxy Adhesives. The epoxy adhesives shall comply with all the requirements of either Type I, Rapid S etting, High Viscosity Epoxy Adhesive or Type II, Standard Setti ng, High Viscosity Epoxy Adhesive as specified in AASHTO M 2 37.
2.Bituminous Adhesive for Pavement Markers. Bituminous adhesive shall be an asphalt material wi th a homogeneously mixed filler formulated primarily for use in bonding pavement markers to Portland cement concret e and asphalt concrete. The adhesive must be heated to a liquid state for application. The epoxy adhesive and/or the bituminous adhesive s hall be listed on the QPL.
721.03 Construction Requirements. Existing raised pavement
markers shall be removed prior to the placement of any overlay or seal course. On pavements that are not to be overl aid or sealed, existing raised pavement markers which are damaged or which conflict with the new markers shall be removed as d irected by the Engineer. Removal of existing pavement markings wi ll not be paid for separately but will be considered subsidiary to other items of the work. The surface to which the marker is to be bonded sha ll be free of dirt, curing compound, grease, oil, moisture, paint , and any other material that would adversely affect the bond of th e adhesive. The adhesive shall be placed uniformly on the surface o r on the bottom of the marker in a quantity sufficient to result in complete coverage of the area of contact of the marker with no voids present and with a slight excess after the marker has been pressed int o place. Markers utilizing epoxy shall be placed in position and pre ssure applied until firm contact is made with the pavement. Markers wi th bituminous adhesive shall have a minimum adhesive pad thicknes s of 3/32" (2.4 mm) after installation. Viscosity of the bitu minous material shall be such that flow about the periphery of the marker does not exceed 1½" (38 mm). Excess epoxy adhesive around t he edge of the marker, excess adhesive on the pavement, and adhesi ve on the exposed surfaces of the markers, shall be immediate ly removed using a solvent and procedure recommended by the ma nufacturer of the markers. No other solvent shall be used. The marker shall be protected against impact until the adhesive has suf ficiently set to resist movement. Epoxy adhesive requires that the mixing operation a nd placing of the markers be performed rapidly. Just before use, components A and B shall be mixed in a 1:1 ratio by volume. Whe n automatic proportioning and mixing machines are used, the tem perature of the components shall be maintained by indirect heating or cooling, if required, for the adhesive to meter, mix, and extru de properly. The maximum temperature shall be such that after proper mixing, there shall be no excess flow of adhesive from under the marker other than that previously specified. When hand mixing the Standard Set Type adhesive, no t more than 1 quart (1 liter) shall be mixed at one time, and the markers shall be aligned and pressed into place within 5 mi nutes after mixing operations are started. Any mixed batch that becom es so viscous that the adhesive cannot be readily extruded from u nder the marker on application of slight pressure shall not be used . Rapid Set Type adhesive shall not be mixed by hand. This adhesive shall be mixed by a 2 component type autom atic mixing and extrusion apparatus. When machine mixing the Standard Set Type adhesive or the Rapid Set Type adhesive, the markers shall be place d within 60 seconds after the adhesive has been mixed and extru ded and no further movement of the marker will be allowed. In addition, no more than 90 seconds shall be permitted between the time the adhesive is pumped into the mixing head and the tim e this adhesive is in place on the roadway and not subject to furth er movement. The mixed adhesive shall not remain in the mixing head for more than 45 seconds. Adhesive remaining in the mixing head longer than this period shall be wasted before resuming the operatio n. Automatic mixing equipment for the epoxy adhesive s hall use positive displacement pumps and shall properly mete r the 2 components in the specified ratio, ± 5% by volume of either component. At the beginning of each day, and at an y other time ordered by the Engineer, the ratio shall be checked by the Contractor in the presence of the Engineer. This check shall be made by disconnecting the mixing heads, or using suitable b ypass valves, and filling 2 suitable containers with the unmixed comp onents. The mixing head shall properly mix the 2 components so that there is no trace of black or white streaks in the mixed materi al. The Standard Set Type adhesive shall not be used wh en either the pavement or the air temperature is less than 50° F (10° C). The Rapid Set Type adhesive shall not be used when eith er the pavement or air temperature is less than 30° F (-1° C). No markers shall be installed if the relative humidity of the air is gr eater than 80% or if the pavement surface is not dry. Voids in a cured, undisturbed sample of the mixed a dhesive obtained from the extrusion nozzle shall not exceed 4%. The Bituminous Type adhesive shall require the use of a melting apparatus. The melting apparatus shall incorporate a means of mixing the material before and during installation to assure homogeneity. Diffuse heat distortion (diffuse plat e) shall be used to prevent overheating the material. A dispensing noz zle shall be utilized that has an independent way of heating the material to provide regulated control over output. The working temperature shall be from 400° F to 450° F (204° C to 232° C). The Bituminous adhesive shall not be used when either the pavement or air temperature is less than 32° F (0° C). The pavemen t markers can only be installed on a dry pavement surface. Reflective markers shall be placed in such manner t hat the reflective face of the marker is perpendicular to a line parallel to the roadway centerline. No pavement markers shall be placed over longitudin al or transverse joints of the pavement surface or over p avement cracks.
721.04 Method of Measurement. Raised Pavement Markers
will be measured by the unit complete in place.
721.05 Basis of Payment. Work completed and accepted and
measured as provided above will be paid for at the contract unit price bid each for Raised Pavement Markers of the t ype specified, which price shall be full compensation for furnishi ng and installing Raised Pavement Markers; and for all materials, lab or, equipment, tools, and incidentals necessary to complete the wo rk. Payment will be made under: Pay Item Pay Unit Raised Pavement Markers (Type___) Each SECTION 722 VACANT
RAISED PAVEMENT MARKER in other states
Get an email when 721 changes
Arkansas revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: , Edition. View official source ↗