Permanent Markings for Concrete Surfaces
Two part epoxide resin paint shall be used for marking concrete surfaces. The paint shall give a matt or semi-gloss finish and is to be formulated on a catalyst cured epoxide resin base. The material should be fuel resistant. The paint shall consist of non-volatile constituents and solvents of which the non-volatile constituent shall be at least 60 percent by mass of the total mass of paint. The epoxide resin content shall not be less than 13 percent of the total mass. The paint shall conform to the tests listed below when applied to 150mm x 100mm test panels of acid chromate pickled hard aluminium prepared in accordance with Part A3 of BS 3900.
Permanent Markings for Bituminous Surfacings
Material for permanent pavement markings shall consist of approved chlorinated rubber paint with a record of at least five years satisfactory performance in Bahrain or in similar climatic conditions. Pigments shall be stable in colour.
The paint shall be a homogeneous blend of pigments, extenders binders and solvents and shall have a minimum volume of solids of 50% +/- 5%. The paint shall be suitable for application by airless spray or conventional spray machines to concrete or bituminous pavements to give a continuous chemically stable film of uniform thickness.
Temporary Markings
Material for temporary pavement markings where required shall be an approved paint. The material shall be mixed in accordance with the manufacturer’s instructions. It shall be capable of complete removal when no longer required.
Retro-Reflective Markings
Glass beads shall be added to the markings where specified to provide a reflective surface. The glass spheres shall be lead-free, uncoated, with a refractive index of 1.90 or greater, have size gradation between 0.4 and 1.30mm diameter and have less than 33% imperfections. Glass beads shall be applied uniformly to the wet paint with a mechanical dispenser at a rate of 0.7 to 1.2kg per litre of paint.
Road markings and Signages
The material used shall be thermoplastic to BS 3262: Road Marking Materials (superimposed type), including amendments. Where there is non conformance, the deviations shall be clearly given in reference to the relevant tables and paragraphs of BS 3262.
The material shall consist of light coloured aggregate, pigment and extender, bound together with hard wearing resins, plasticized with oil as necessary in approximately the following proportions by weight:
Aggregate 40 parts (approximate)
Ballotini 20 parts (as laid composition)
Pigment and Extender 20 parts (the sprayed-on ballotini )
Binder 20 parts
The grading of various ingredients shall be such that the final product, when in a molten state, can be sprayed on the surface at approximately 2.0 mm thickness. The aggregate shall consist of white silica sand, crushed calcite, calcined flint or quartz, or other approved aggregate, and the colour shall comply with the requirements laid down in paragraph 4b of BS 3262 (Part I), i.e. the luminance factor compared with magnesium carbonate shall be not less than 50.
Ballotini incorporated in the mixture shall be in accordance with paragraph 5a of BS 3262 (Part I) i.e. all shall pass a No.10 BS sieve not more than 10 percent shall pass a No.36 sieve; and not less than 80 percent shall be transparent glass, reasonably spherical, and free from flaws. The Ballotini sprayed on to the line shall conform to the same limits of colour and roundness, but may be smaller; not more than 10 percent shall pass a No.72 BS sieve.
The pigment shall be titanium dioxide (in accordance with paragraph 6a (i) of BS 3262 (Part I) and shall be not less than 10 percent by weight of the mix. The extender shall be whiting (in accordance with paragraph 6b of BS 3262 (Part I). The total content of pigment and extender shall be 18-22 percent (in accordance with paragraph 6c of BS 3262 (Part I). The binder shall not contain more than 5 percent of resin or other acidic material. It shall consist mainly of hydrocarbon resins plasticised with mineral oil.
The resins used shall be of a colour at least as pale as Grade WG resin. It shall have an acid value not greater than 2, and must pass the heat stability test described below. The oil used as plasticiser shall be a mineral oil with colour and viscosity as defined in paragraph 7a (ii) of BS 3262 (Part I), i.e. at least as pale as grade 4 on the P.R.S. Shellac and Varnish “A” Disc, and 1/2 to 3 1/2 poises at 25 ° C viscosity. In addition, when heated for 16 hours at 150 ° C it shall not darken excessively. The softening point of the binder shall be used only as a guide to quality control, and the behaviour of the thermoplastic shall be judged from the performance tests described below.
The viscosity of the melted binder at the spraying temperature must be such as to produce a thermoplastic mix of the required spraying properties.
The composition of the laid material as found on analysis shall comply with the requirements of Table 1 of BS 3262 (Part I). The temperature limits imposed by BS 3262 (Part I) for materials based on resin shall not apply. Temperatures up to 220°C may be used; at these temperatures the material shall not discolour in the time required for its use.
Containers shall be made of a material which does not contaminate the contents and will protect the contents from contamination. The capacity of each container shall be not less than 25 kg or more than 100 kg. Each container shall be clearly marked with the manufacturer’s name, batch number and date of manufacture. As stated in these specifications, the binder shall be hydrocarbon resins, and shall not contain more than 5 percent of resin.
Reflective sheeting (panel)
The Reflective sheeting shall be Scotchlite Reflective Sheeting High Intensity Grade Series 2800 or similar.
Durability. Processed and supplied in accordance with recommended procedures the reflective material shall be weather resistant and, shall show no discolouration, cracking, blistering or dimensional change.
The local manufacturer must submit a Warranty Certificate from reflective sheeting manufacturer guaranteeing all signs manufactured by him for a minimum period of 7 years against stripping, delamination, discolouring and loss of reflectivity.
He must also submit manufacturer’s specification, technical data, and workshop processing technique for the reflective sheeting when asked by the consultant.
Intended use. The reflective sheeting specified herein is intended for use on surfaces of road signs to assure their optimum visibility by day and at night when exposed to a light source and whether dry or totally wet by rain.
The Contractor shall select colours as approved by the consultant. The application on the panel substation shall as per the Silk screen method unless the Manufacture states that this method is not practicable in which case the Manufacture shall submit, for consultant and Client approval, alternative application method explaining the reason for the change and listing and specifying for which sign the alternative method shall be applied.
Sign face layout. The preparation of the legend and backgrounds of the sign panels shall comply with the tender specifications and drawings unless modified by the consultant.
The colour of Signs shall be:
White legend and borders on blue background for principal and secondary destinations.
Black legend and borders on white background for local destinations.
The “NASKH” style for alphabet, numerals and other characters will be used for the Arabic script.
For the English script use “MEDIUM TRANSPORT” for white lettering on blue background. For black lettering on white background use “HEAVY TRANSPORT”.
The lettering size shall be as stated on the Drawings.
The Contractor shall submit to the consultant for approval, three (3) copies of drawings for all special sign faces and all signs faces bearing messages, showing the design and/or arrangement and spacing of both the Arabic and English sign messages. Official town names and their English and Arabic spelling shall be as provided by the consultant. Size and style of lettering shall be as shown on the plans or as otherwise approved by the consultant.
The shape, size, legend and colours of all signs shall be as shown on the drawings.
Substrate Material (Panel Base)
Warning and Requesting Signs
Warning and regulatory signs shall be produced on half hard 99% – 99.5% aluminium alloy sheets not less than 3 mm thick and conforming to BS 1470. The sheet plates shall be free from laminations, blisters, ragged edged or other defects and precut to the required sizes with rounded edges. All sheets shall be uniform in thickness shearing, cutting and punching shall be done prior to preparing the plates for the application of the reflectorised material.
The plates shall be cleaned wax free. They shall be degreased by solvent immersion followed by scrubbing with abrasive cleaner. The plates will then be etched by scrubbing, brushing, or spraying with a 6-8% phosphoric acid at 40 degree C and then removed by cold water rinse followed by drying with warm air.
Advance Direction and Guide Signs.
Advance Direction and Guide Signs, shall be produced from extruded aluminium double skin planks and shall be as shown the Drawings. Guide signs with no vertical or horizontal joints can be produced from 3mm thick Aluminium plates as for Warning and Requesting Signs and strengthened by aluminium strengthening channels all along the length of the signs at 30cms (centre to centre) spacing. The aluminium strengthening channels to be welded or fixed to the back of the sign plate, without rivets, screws, nuts and bolts or any form of drilling in the sign face. The double skin aluminium planks should be free from all transit and extrusion defects and prepared as for Warning and Requesting Signs.
Retroreflecting road studs (cat’s eyes)
Road studs shall conform to BS1463 and BS 873.
Site Work for Permanent Markings for Concrete Surfaces
The paint shall be applied to the panels by means of a film applicator to give a wet film thickness of 0.152mm.
(i) The surface dry time shall not be more than 90 minutes when tested in accordance with Part C2 of BS 3900.
(ii) The hard dry time shall be not more than 6 hours when tested in accordance with Part C3 of BS 3900.
(iii) The final cure shall be within 7 days.
New markings shall not be applied to wet surfaces, or to concrete less than 28 days old, or to concrete which still retains traces of the curing liquid.
Epoxide resin paint shall be sprayed on or brush applied in accordance with the manufacturer’s instructions.
Permanent Markings for Bituminous Surfacings
A tack coat or sacrificial layer of chlorinated rubber paint shall be applied to the pavement in order to overcome any bleeding of oils up through the paint which may lead to discoloration of the marking. The second coat of paint shall be applied no earlier that that specified in the manufacturer’s recommendations. Where tack surround markings are required these shall be provided by extension of the area to be tack coated. New concrete shall be cleaned of all curing compound and at least 28 days old prior to application of markings
The layout and colour of the markings shall be as indicated on the Drawings. The finished thickness of markings shall be 100 microns, or greater if recommended by the manufacturer and accepted by the consultant, measured on a steel plate. The finished markings shall be free from raggedness on sides and ends.
Temporary Markings
Temporary markings placed during stages of construction shall be removed prior to placing further asphalt courses or permanent markings. Temporary pavement marking, when not needed any more shall, where the consultant instructs, be removed by chipping and wire brushing or other approved means without damaging the surface of the asphalt.
The Contractor shall maintain temporary markings in a clearly legible condition and shall repaint as necessary.
Road markings and Signages
The pavement markings shall be painted on the road to the dimensions and in the location as shown on the drawings or as directed by the consultant. The Contractor shall set out the markings and obtain the consultant approval before commencing the work
Application
The Contractor shall set out the pre-marking and obtain the consultant’s approval before commencing the application of pavement marking. Application shall be mobile sprayer, either hand-propelled or self-propelled. The road surface shall be dry, and free of loose, detritus, mud, or other extraneous matter. Where old paint or thermo-plastic materials are present, the manufacturers shall be consulted as to whether the surface is suitable. A tack coat should not be necessary when the thermoplastic is applied to carriageways. Where it is considered necessary to use a tack coat, this shall be rubberised type recommended by the manufacturers of the thermo- plastic. In addition to the ballotini included in the mix, an additional quantity of glass beads shall be sprayed on to the hot Spray-plastic line at the time of application. The rate of application shall be of about 0.5 kg/m2. The material shall be laid in intermittent lines or continuous lines 2.0 mm thick using an approved pressure spray unit as directed by the consultant. The finished lines shall be free from “raggedness” on sides and ends and be in true plane with the general alignment of the carriageway. The upper surface of the lines shall be level, uniform and free from streaks. The composition shall possess an approximate specific gravity of 2.0. The compound shall have an open flash point exceeding 230 ° C.
Removal of road markings
Whenever instructed by the consultant, the Contractor shall remove existing Pavement Marking. Removal of Pavement Marking shall be done only in the areas where existing Asphaltic Layer has not to be removed nor milled nor overlaid. Removal of Pavement Marking shall be done by a method, proposed by the Contractor and approved by the consultant, which method shall not damage the surface of the asphaltic layer. Removal of Pavement Marking shall be measured by square metre. The Unit Price shall constitute full compensation for all labour, equipment, tools, supplies and incidentals necessary to complete the Work.
Road Signage
All types of traffic signs and guide signs must be fabricated by an approved company in a fabrication plant that meets the minimum requirements for the handling and processing of reflective sheeting. The manufacturer must submit a recommendation stating that his plant is satisfactorily equipped for the hot vacuum application of reflective sheet and will not hamper the issue of the warranty certificate as required by this specification. This work shall consist of fabricating, supplying and installing reflectorised sign panels, sign supports, sign mounting systems and sign support foundations as shown on the drawings, in accordance with the specifications or as directed by the consultant. Location of the signs shall be as per the Project drawings or as ordered by the consultant and approved by the Competent Authority before erecting them.
Paint system
Aluminium, backs of all signs must be coated with the following paint system:
Aluminium surfaces to be cleaned and washed with Navi Wash.
One coat from a two-component etch primer containing phosphoric acid and rust-preventing pigments to be applied by spray application.
One coat from a high quality two-pack epoxy coating, Pigmented with Micaciouus Iron Oxide (MIO) processing high resistance to ultraviolet radiation and providing a tough, hardwearing, chemical and abrasion resistant coating, to be applied by spray application.
Each back face shall have written the name of the manufacturer and the year of make.
Galvanized surfaces, covering all not dipped galvanized and electro galvanized posts, steel sections, and fabricated sign mounting modules to be coated with the following paint system.
Galvanized surfaces to be cleaned and degreased. Some types of galvanized steel may require light blasting with fire abrasive.
One coat from a two-component etc primer containing phosphoric acid and rust-preventing pigments to be applied by spray application.
One coat from a high quality two-pack epoxy undercoat HB,MIO to be applied by spray application.
One coat from a high quality two-pack epoxy top coat MIO to be applied by spray application.
Mounting system
The following mounting system must also ensure the structural stability for all directional and rectangular signs.
All signs to be strengthend by welding and/or fixing 2 lengths of extruded aluminium channels at the back. Method of fixing must not be by rivets, nuts and bolts or any method that requires drilling of holes in the sign face.
Stainless steel clips High Tension Anti-Rotation Strips with appropriate fittings will then be slid in the channels for mounting the signs on their respective posts all as per tender drawings.
Double skin planks to fit together with a male and female joint and no additional joining clamp must be necessary. Each plank will have a central channel on the back for fixing a stainless steel clamp that mounts the plank on signs posts fabricated from MSI sections all as per tender drawings. Stainless steel clips can also be fixed in the channel for mounting the planks on circular posts.
Supports for ground mounted signs
Posts for permanent traffic signs shall comply with BS 873: Part 7. Surface protection shall comply with BS 873: Part 6. Posts shall be tubular or rectangular hollow section complying with BS EN 10 210.
Posts shall not protrude above the top of the sign unless supporting an external luminaire, in which case the protrusion shall be kept to a minimum.
The structural steel sign posts shall be erected in a vertical position on a previously prepared foundation, with the tops of the posts in each sign installation even-level with each other. The faces of the supporting posts shall be flush with the sign through the contract areas.
The length of the posts for each traffic sign shown on the drawings shall be determined by the Contractor before ordering in order to meet the existing field conditions and to conform to sign-mounting heights shown on the drawings. After fabrication posts shall be galvanized.
All fabrication shall be completed and ready for assembly before galvanizing. No punching, drilling or cutting shall be permitted after galvanizing. Any part of the pipe from which the galvanizing has been damaged in fabrication, transit, or erection or when bare metal is exposed shall be repaired by application of galvanizing repair compounds approved by the consultant.
Retroreflecting road studs (cat’s eyes)
Reflective studs shall be installed and anchored to the pavement as follows:
Drill a hole into the asphalt pavement to the dimensions recommended by the manufacturer or 35mm x 80mm x 55mm x 80mm. Ensure that the hole is free of dust and also the pavement surface within a radius of 200mm of the hole is free from debris and dust. Fill the hole to overflowing with two parts, asbestos-free epoxy adhesive specifically formatted for the purpose intended.
Insert anchor system and align the marker axis to present the reflective flow, and press firmly to bed in the marker ensuring a good bed of compound under the Road stud and a solid fixing. Scrape off any surplus bedding material and protect the installed marker until the bedding material has completely set. Clean off any surplus grouting and protect the road stud from traffic for approximately sixty minutes.