Article 1 — Description
Remove graffiti or apply anti -graffiti coati ng on concrete or steel .
Article 2 — Materials
Furnish acrylic latex paint meeting the requirements of Item 446, “Field Cleaning and Painting Steel ,” for steel structures. Furnish concrete paint or opaque sealer in accordance with Item 427, “Surface Finishes for Concr ete,” for concrete structures unless otherwise shown on the plans. Furnish anti -graffiti coating of the type specified, in accordance with DMS -8111 , “Anti -Graffiti Coatings.” Furnish graffiti removal chemicals as approved.
Article 3 — Work Methods
Graffiti is defined as inscriptions or drawings placed on fixtures, structures, and riprap. Remove graffiti from signs as directed. Work requests are made on a callout basis. Begin graffiti removal within 24 hr. of notification, unless otherwise shown on the plans. Shape treated area to a rectangular configuration. Control dust or water to prevent hazard to traffic. Ensure treated areas exhibit a uniform clean appearance upon completion. Follow the manufacturer’s recommendations and use a low -pressure (less than 1,000 psi) water wash when using a chemical cleaning method. Verify whether an anti -graffiti coating is present before performing any maintenance activity. If construction records are not available for the structure, perform a m ethyl ethyl ketone (MEK) rub test on the existing coating by rubbing the coating with a rag soaked in MEK or an anti -graffiti cleaner. If the MEK or anti -graffiti cleaner removes or damages the coating, then the coating is not an anti -graffiti coating. To determine whether an anti -graffiti coating is Type II or Type III , clean a portion of the graffiti using a liquid detergent and water. If the graffiti can be removed by the soap and water, then the coating is a Type III anti-graffiti coating, and a low -pressure water blast may be used to remove the graffiti.
3.1 Graffiti Removal . Remove graffiti by any of the following methods as specified.
3.1.1 Surfaces Without Anti -Graffiti Coating .
3.1.1.1. Concrete Structures. Remove graffiti by any of the following methods. Blast Cleaning . Use abrasive blasting, water blasting, or steam cleaning. Chemical Cleaning . Follow the manufacturer’s recommendations . Painting . Prepare surface by approved methods before painting. Paint over the graffiti on concrete in accordance with Item 427. Match the color of the existing surface. 988 3.1.1.2. Metal Surfaces. Remove graffiti by either of the following methods. Painted Surfaces. Prepare surface as approved. Paint over the graffiti on metal in accordance with Item 446. Match the color of the existing surface. Galvanized or Unpainted Surfaces . Use chemical cleaning.
3.1.2 Surfaces with Anti -Graffiti Coating . Fully remove graffiti as described below without damaging the
anti-graffiti coating. Repair any damage to the anti -graffiti coating without additional cost to the Department. Anti-Graffiti Coating, Type II (Solvent -Cleanable) . Use solvents or chemical cleaning to fully remove graffiti without damaging the anti -graffiti coating. Use a low -pressure water rinse as desired for a final wash of the cleaned surface. Anti-Graffiti Coati ng, Type III (Water -Cleanable) . Use water and scrubbing or a low -pressure water wash (less than 1,500 psi at the surface) to fully remove graffiti without damaging the anti -graffiti coating. Note —Overly high pressures or overly hard brushes will damage the anti-graffiti coating.
3.2 Application of Anti -Graffiti Coating . Blast clean all concrete surfaces in accordance with Item 427 to
remove old coatings, laitance, curing compound, dirt, grime, and other contaminants. Apply a primer, when required by the manufacturer, in conformance with the manufacturer’s recommendations. Apply anti -graffiti coatings on surfaces specified on the plans. Anti -graffiti coatings require a dry surface. Apply anti -graffiti coatings when the temperature of the atmosphere, substrate surface, and material is 50°F or above. Ensure anti -graffiti coatings are not applied when impending weather conditions might result in damage to the fresh coating. Ensure anti -graffiti coatings are not applied over any existing appearance coating unless otherwise shown on the plans. Apply anti -graffiti coatings by spray, roller, or brush at the application rates recommended by the manufacturer. Ensure the anti -graffiti coating is not thinned without prior approval. Replace anti -graffiti coatings not meeting an MEK rub test when tested in accordance with ASTM D4752.
Article 4 — Measurement
This Item will be measured by the square foot. The minimum quantity per callout is 50 sq. ft. unless otherwise shown on the plans .
Article 5 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “Graffiti Removal (Blast Cleaning),” “Graffiti Removal (Painting),” “Graffiti Removal (Chemical Cleaning),” “Anti -Graffiti Coating (Permanent —Type II),” and “Anti-Graffiti Coating Permanent —Type III).” This price is full compensation for cleaning, painting, equipment, labor, materials, tools, and incidentals.