Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
  • E01F9/00—Arrangement of road signs or traffic signals; Arrangements for enforcing caution
  • E01F9/60—Upright bodies, e.g. marker posts or bollards; Supports for road signs
  • E01F9/623—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection
  • E01F9/627—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection self-righting after deflection or displacement
  • E01F9/629—Traffic guidance, warning or control posts, bollards, pillars or like upstanding bodies or structures
• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
  • E01F9/00—Arrangement of road signs or traffic signals; Arrangements for enforcing caution
  • E01F9/60—Upright bodies, e.g. marker posts or bollards; Supports for road signs
  • E01F9/604—Upright bodies, e.g. marker posts or bollards; Supports for road signs specially adapted for particular signalling purposes, e.g. for indicating curves, road works or pedestrian crossings
  • E01F9/608—Upright bodies, e.g. marker posts or bollards; Supports for road signs specially adapted for particular signalling purposes, e.g. for indicating curves, road works or pedestrian crossings for guiding, warning or controlling traffic, e.g. delineator posts or milestones

Definitions

• This invention relates to roadway markers or guide posts and more particularly to resilient roadway markers which, when struck by a vehicle, give way without suffering impairing damage and which return to the upright position after the vehicle has passed.
• Australian Patent 526,508 discloses a fibreglass roadway marker which is capable of being driven into the ground when being installed. According to that specification, the structural requirements of resilience and elasticity are inconsistent with the longitudinal rigidity required to resist bending of the post as it is driven into the ground as such longitudinal rigidity tends to prevent the post from yielding to lateral impact after it has been installed.
• the roadway marker disclosed in Australian specification 526,508 consists of a fibre-reinforced synthetic material which contains a combination of randomly oriented and longitudinally oriented fibres imbedded in 20 to 40% by weight resin binder.
• the specification further discloses that at least 7% but not more than 60% of the fibres are randomly oriented to increase tensile strength (and hence transverse flexibility) with the remainder of the fibres being longitudinally oriented to provide longitudinal rigidity.
• Prior art fibreglass roadway marker posts have been formed by a pultrusion process which restricts the outer surface to being part of the pigmented resin in which the fibreglass is embedded. Thus, the post tends to discolour quickly when exposed to sunlight for prolonged periods. Furthermore, such a process does not permit the formation of recesses in the marker for receiving strips of reflective material.
• a roadway marker post comprising an elongated structure of fibreglass reinforced resin material characterised in that the resin is a catalytic setting resin and the fibres are substantially unidirectional.
• a method for manufacturing a roadway marker post comprising the steps of:-
• Fig. 1 is a partly broken away, front elevational view of a raodway marker post according to one embodiment of the invention.
• Fig. 2 is a front elevational view of the upper portion of a modified roadway marker post.
• Fig. 3 is a cross-sectional view taken along lines
• FIG. 1 A-A of Fig. 1, Fig. 4 is a schematic front elevational view of an undeformed roadway marker post, Fig. 5 is a schematic view similar to Fig. 4 but with the post deformed, and. Fig. 6 is a front elevational view of the top portion of a roadway marker post according to one embodiment of the invention and a jig for use in driving the post into the ground.
• the general shape and configuration of a roadway marker post according to the invention is shown in Figs. 1 and 2.
• the post 10 is of arcuate cross-section and has an upper portion 11, a body portion 12 and a lower or leading portion 13. As can be seen in Fig. 1, the leading portion 13 of the post 10 is pointed to assist the driving of the post into the ground.
• the upper portion 11 of the post 10 may carry embossed markings 14 (see Fig. 2) or a recess 15 (see Fig. 1) for receiving a strip of reflector tape. Barbs 16 may be provided on the leading portion 13 to resist withdrawal of the post 10 from the ground.
• the post 10 consists of a fibreglass reinforced resin material in which the fibres are substantially unidirectionally located in a matrix of a catalytic setting resin.
• the resin consists of a base material of saturated and unsaturated dibasic acids, and a dihydric glycol.
• the base material is dissolved in the monomer solvent, styrene, making it fluid.
• the resin is promoted by one or a combination of:-
• the catalyst added to the resin may be one of the following catalysts or a combination thereof:- (i) benzol peroxide (ii) methyl ethyl ketone peroxide
• the abovementioned catalyst may include one or more of the following dilutents:-
• the properties of the finished polyester is altered as desired.
• the preferred glycols and acids for a finished composite resin are:-
• neopentylglycolisophthalic polyester resin ii) isophthtalic polyester resin (iii)neopentylglycol orthophthalic resin (iv) orthophthalic polyester resin
• resins are not inherently flexible 25-75% by weight of a flexible resin is added.
• a particularly suitable flexible resin is RCL which is marketed by British Paints.
• fillers may be included in the amount from
• the filler can be selected from the group comprising:- (i) calcium carbonate (ii) alumina trihydrate (iii)asbestos flock (iv) zircon flour (v) Calindria 244
• a single filler, or a combination of fillers may be used in different polyester composites to provide the optimum resin composites under different conditions.
• the fibreglass used in the roadway marker post is substantially unidirectional save for a very small amount of cross woven fibre used to maintain the greater majority of the fibres in their undirection configuration.
• the use of this type of glass (defined as 'S' glass and 'E' glass in the form of scrimmed unidirectional glass) gives a very high modulus fibre and are often used in very high performance laminates associated with the aerospace industry.
• the total resin component is present in an amount from 30 to 225% of the weight of the fibreglass.
• a preferred post is formed from a specially woven E type unidirectional glass in the form of a 4 inch scrimmed taped and a catalytic setting resin formed from:- a) isophthalc non-flexible resin b) RCL flexible resin (marketed by British Paints ) c) styrene as a thinner d) calcium carbonate as a filler.
• the amount of each component is varied according to the physical characteristics required of the marker post. However, those amount will be within the ranges identified above.
• the roadway marker may be formed in a 200-2,500 pounds per square inch cold/hot press machine.
• the unidirectional glass is placed into the mould at different pre-calculated sections of the mould to create different mechanics of the reinforcement.
• the changes the stress/strain characteristics of the reinforced plastic will be apparent from the following discussions which considers the schematic post shown in Fig. 4 (undeformed) and Fig. 5 (deformed) from the simple strength of materials viewpoint.
• the strain in the matrix (e m ) will be equal to the strain in the fibres (e f ):-
• S m is the stress at failure of the matrix (i.e. its strength) and S f is the stress at failure of the fibre (i.e. its strength) is desirable to match the ratios of stress at failure so that:-
• the load P required to strain the composite shown in Fig. 4 and 5 is related to the stress of the composite and the cross-sectional area of the composite :-
• the total load P comprises the load arried by the f ibres P f and the load carried by the matrix P m :-
• E k E f V f + E m (1-V f ) where: E k is tensile modulus of the composite E f is tensile modulus of the fibres E m is tensile modulus of the matrix
• the tensile modulus of the post can be calculated once the volume fraction of the fibres has been determined, or alternatively, once the tensile modulus has been set, the volume fraction of the fibres required to achieve the modulus can be readily calculated.
• the roadside marker post may be driven into the ground by the use of a jig as shown in Fig. 6, which also serves to help keep the marker straight.
• the jig acts in the manner of a pile-driver, and the distance moved by the marker will depend on the resistance offered by the ground and the velocity of the jig at the moment of impact, as well as the mass of the jig itself.
• the jig 30 has grips or handles 31 which receive the edges of the post 10 and a striking plate 32 which constitutes the major portion of the mass of the jig.
• roadway marker posts according to the invention do not lend themselves to be driven into hard ground by the application of a force to their free end as is the case with the posts described in the Australian patent specification 526,508. In normal circumstances, a hole will be dug in the ground and the marker placed therein. The barbs formed at or near the bottom of the marker post resist removal of the post from the ground.
• the driving jig shown in Fig. 6 is placed over a substantial portion of the marker to prevent flexing and to protect the top of the marker.
• a coat of polyurethane may be applied to the post by exposing a freshly applied paint film for a short period in a vaporised catalyst atmosphere.
• a process can utilise urethane linked alkyds, acrylics, epoxies, phenolics and polyester resins.
• Appropriate selection of the polymer coating to give a desired repeating molecular unit in the cured film can give rise to a wide variety of properties of the film.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Road Signs Or Road Markings (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=3694492

Family Applications (1)

Country Status (2)

Families Citing this family (4)

Family Cites Families (8)

• 1986
  • 1986-12-24 EP EP87900031A patent/EP0250489A1/de not_active Withdrawn
  • 1986-12-24 WO PCT/AU1986/000395 patent/WO1987003921A1/en unknown

Non-Patent Citations (1)

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