Section 685 – Anti-Graffiti Protection and Graffiti Removal
SECTION 685 – ANTI-GRAFFITI PROTECTION AND GRAFFITI REMOVAL
##This section cross-references Section 160 – is it included in the specification?:
This section specifies the requirements for the supply of materials, the application of anti-graffiti coating systems to various substrate surfaces, the removal of graffiti markings, graffiti removal maintenance requirements and relevant testing, associated with roadside furniture and structures including bridges, pedestrian underpasses, facings of reinforced soil structures, noise walls, barriers, retaining walls, traffic control boxes, and similar features.
The section is applicable to various substrate surfaces including normal concrete, lightweight concrete, glass fibre reinforced concrete, timber, acrylic plastic, painted steel, normal bricks, concrete blocks, besser blocks, cement render, sandstone, limestone and painted surfaces. Substrate surfaces other than concrete may require some variation of the usual treatment applicable to concrete surfaces. Manufacturers’ recommendations shall be strictly adhered to for all substrate surfaces unless otherwise stated in this section.
Australian Standards are referenced in an abbreviated form (e.g. AS 2700).
(a) Australian Standards
|AS 1580.108.2||Dry Film Thickness-Paint Inspection Gauge|
|AS 1580.408.5||Adhesion-Pull-Off Test|
|AS 1580.602.3||Boller Test|
|AS 1627.1||Metal finishing, Preparation and pre-treatment of surfaces – Removal of oil, grease and related contamination|
|AS 1627.4||Metal finishing, Preparation and pre-treatment of surfaces – Abrasive blast cleaning of steel|
|AS 2311||Painting of Buildings|
|AS 2312||Guide to the Protection of Iron and Steel Against Exterior Atmospheric Corrosion|
|AS 2700||Colours Standards for General Purposes|
(b) Additional Test Methods
ASTM D4263-83 (2005) Moisture in Concrete by the Plastic Sheet Method
ASTM D4414-84 (1990) Wet Film Thickness
Graffiti: The unauthorised defacement of a surface by words, figures or obliteration.
Substrate: The material constituting the surface marked, e.g. concrete, timber.
Graffiti Marking: The defacement material, e.g. paint, felt-tip pen.
Anti-Graffiti Coating: A coating material which improves the graffiti resistance of many substrate surfaces. It facilitates the easy removal of graffiti by acting as an impermeable medium which stops the deep penetration of graffiti markings into the substrate pores and by preventing a firm attachment to the surface.
Non-Sacrificial Anti-Graffiti Coating: Longlife (permanent) coatings which can withstand several cycles of repeated defacement/cleaning processes.
Sacrificial Anti-Graffiti Coatings: Temporary coatings which are partially or totally removed from the substrate surface together with the graffiti during the cleaning process. Sacrificial coatings are then re-coated.
Anti-graffiti coatings, graffiti removal agents and decorative/anti-carbonation coatings shall be used in accordance with the manufacturer’s recommendations, materials safety data sheets and as specified in this section.
The Contractor shall submit for review by the Superintendent not less than 14 days prior to the commencement of the anti-graffiti protection works, details of the anti-graffiti protection operations including information on the proposed anti-graffiti coatings, graffiti removers, decorative/anti-carbonation coatings, substrate preparation, method of application, equipment and operators, demonstrating compliance with the requirements of this specification.
Material details shall include information on the properties of the proposed products, documented evidence of previous performance and relevant test results, which shall not be more than twenty-four (24) months old.
HP Anti-graffiti protection works shall not take place until the Contractor’s proposed materials and procedures have been reviewed and accepted by the Superintendent.
685.05 SURFACE PREPARATION
The surface preparation shall be in accordance with the manufacturer’s recommendations for the coating system to be applied and as specified in this section.
All dust, dirt and other surface contaminants shall be removed by appropriate means and as approved by the Superintendent. The surface shall then be washed with water such that grease and oil contaminants, including remnants of curing membranes, shall be removed from the surface by the use of appropriate solvents or detergents followed by the water washing in accordance with AS 1627.1.
Where an anti-graffiti coating system is specified, the substrate shall be free of all graffiti, graffiti shadows, paints, or any other surface contaminants which would be visible through the coating.
Where shadows of previously removed graffiti are likely to be clearly visible through a coating, a suitable anti-bleed stain sealer shall be applied prior to the application of any subsequent coatings. If the problem persists the Contractor shall advise the Superintendent accordingly.
Where required to promote adhesion of the coating system, some concrete and other substrate surfaces may be cleaned by whip blasting with a fine grade garnet or surface etched with an approved acid wash followed by a water wash in accordance with AS 1627.1. Any abrasive blast cleaning shall be carried out in accordance with AS 1627.4 and appropriate regulations imposed by the local government authority and the EPA.
685.06 ANTI-GRAFFITI COATING SYSTEMS
The anti-graffiti coating system shall be non-sacrificial, clear or pigmented coating to a specified colour unless otherwise approved by the Superintendent. The coating system shall be an acrylic-copolymer, acrylic-epoxy, polyurethane or polyurea type. All coats in the system shall be of the same brand and must be compatible with each other.
The use of sacrificial anti-graffiti coatings shall be subject to the approval of the Superintendent.
Substrate surfaces other than concrete may require variations of the usual treatment applied to concrete surfaces. Highly porous substrates may require a pore-filling primer coat prior to applying a final anti-graffiti finish. For relatively soft surfaces the primer and/or finish coat shall also offer surface binding and toughening effect. Manufacturers’ recommendations shall be sought in all such cases.