US 3164071 A
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Description (OCR text may contain errors)
Jan. 5, 1965 D. RUBENSTEIN 3,164,071
TRAFFIC MARKERS F11ed Aug. 19, 1960 2 sheets-sheet 1 om O .g'y p .O. f. 3
INVENTOR D. RUBEN STEIN TRAFFIC MARKERS Jan. 5, 1965 2 Sheets-Sheet 2 Filed Aug. 19, 1960 INVEN TOR.
United States Patent() 3,164,071 TRAFFIC MARKERS David Rubenstein, 2750 2nd Ave., San Diego, Calif. Filed Ang. I9, 1960, Ser. No. 50,767 15 Claims. (Qi. 94`l.5)
This invention relates to improvements in traiic control markers and devices for streets, roads, highways, freev Ways, expressways, and airfields.
An object of the present invention is to provide mass produced, durable, long lasting, relatively maintenance free tratiicc control markers and devices.
Another object of the invention is to provide traiiic control markers and devices having permanently colored surface layer constructions of white, black, red, green, yellow, amber or in fact any other colo-r useful and used in traiiic control markers and devices.
Another object of the invention is to provide traffic control markers and devices having reinforcing means that are resilient and particularly adapted to being resistant to impact and crushing from loads imposed by wheels of moving cars, trucks and vehicles.
Another object of the invention is to provide traffic control markers and devices capable of being used in all weather conditions and having maximum visibility.
Another object of the invention is t0 provide trahie control markers and devices having included in their construction means adapted to melt snow or ice so as to have such markers and devices always exposed to view.
Another object of the invention is to provide traiiic control markers and devices having included in their construction surface components of their surface layer construction providing color and luminescent pigments that are decorative or functional and are fixed for night illumination.
Another object of the invention is to provide trahie control markers and devices having illuminating sources of light in their make-up and operative by automative and automated illumination controls.
Another object of the invention is to provide traffic control markers and devices having or providing means adapted to increased safety to motorists on highways, roads and streets.
In patents from prior applications, I have disclosed and claimed high strength structural elements and methods of making them in which a concrete block or other stonelike structure is provided with a high tensile strength surface layer inegrally bonded into the concrete; and, specifically, I have `disclosed the use of plastic resin compositions reinforced with fiber glass or other high tensile fiber strength ber in Woven or unwoven mat form. My several prior applications refer to prestressed preloaded structures and constructions adapted to use as dynamically loaded structures highly resistant to such loadings.
The improvements and inventions herein claimed and disclosed may be and are advantageously made in conjunction with these prior inventions, in part in some cases and in part in other cases.
The extensive development of the Nations highways, roads, freeways and expressways has brought out the need for more eicient means and devices for control of traffic, and, particularly to better and safer permanent markers and devices. The use of traiic control markers and devices on streets, roads, highways, freeways and expressways has been occasioned with substantial amounts of painting and maintenance costs as well as replacements of damaged and destroyed markers and devices, which as now presently used have a short time life in use. Particularly, colors used in traic control require constant replacement and painting.
In the drawings herewith provided I have shown preferred embodiments of my invention and have described the same and modications thereof in this specification. It is intended and is to be understood that these disclosed' embodiments are not intended to be exhaustive or limiting of the invention, but on the contrary, are disclosed and chosen for the purpose of illustrating the invention in order that others skilled in the art may so fully understand the invention, its principles and applications thereof, that they may embody it and adapt it in numerous forms, each as may be best suited to the requirements of its particular use.
In the drawings:
FIGURE 1 is an isometric View of a reinforced traffic marker and device embodying features of the instant invention; n
FIGURE 2 is a view of a traffic marker and device in cross-section having integral reinforcing and strengthening means of the invention;
FIGURE 3 is an isometric view of a traic lane marker set flush with the surface of a highway and an embodiment of the invention;
FIGURE 4 is a View of a traic control marker and device having a series of grooves and patterned surfaces;
FIGURE 5 is a View of a traffic control marker and device having an illuminating means providing safety lighting means;
FIGURE 6 is an isometric view of a traflic control marker and device having a heating device for melting ice and snow and provide means for keeping an embodiment of the invention visible in inclement weather.
I have found, by incorporating in the various plastic mixture components, color and luminescent pigments or materials adapted for providing phosphorescence or iiuorescence, the surface mopenents of the rubber-concrete structural building unit of the invention can be made decorative or functional and fixed for night illumination. By building bridge approaches with such plastic resin composition reinforced components, safety features, light and contrasting colors introduced at the time of manufacture, will, when illuminated by approaching head lights of vehicles, provide permanent safety features in the embodiments of the invention.
Sandwich type laminations that incorporate structural, load hearing properties, color, white or otherwise, luminescence, smooth highly polished surfaces or mat or textured surfaces, can also be sandwiched to insulating components of any one of a number of types, one of which could be an expanded material, non-rigid, expanded product that is based on a styrene-acrylonitrile copolymer combined with a butadiene-1,3,-acrylonitrile copolymer.V This laminate is characterized by a high resistance to compression in comparison to its low density (6 to 8 lbs.) per cu. ft. by low water absorption, and by low thermal conductivity. It also possesses a high degree of resistance to various chemicals and solvents, particularly petroleum products such as kerosene and fuel oil. Laminated memabsorb shock and impact loads. Another expanded plastic that can be incorporated'in the laminate is diisocyanate foamed maerial which is composed of two alkyds and an isocyanate. When all three are put together and water added the material foams in place. A variety of properties may be achieved with the wide variety of materials available with the sandwich type,- st-ructure. It is possible to accentuate any desirable characteristicl such as resilient resistance, resilience, shock-proofing, moisture proofing, color, design patterns, smoothness, texture, load bearing capacities in compression, tension, shear and torsion. All these capacities and properties can be designed into the resulting structure of the invention and produced in a factory as finished components ready for installation on-site with no additional field production labor, using labor only for installation and assembly, except labor used in mechanical prestressing preloads into embodiments of the invention in the operation of the mechanical means providing such prestressed preloads.
' The rubber-concrete core-bodies and laminated surface layers thereof provide laminated constructions having resiliency and compressibility stress and strain relieving capacity that is rubberlike, and that provides articulation and movement between laminated members as Well as surface articulation movement abilities of stretch, tension, compression, torsion, twist, shear and generally flexible movements without separation of the members of the laminate or separation or failure from the concrete or rubber-concrete body within the designed limits yof stress and strain of the lamination.
The constructions and structural components of the invention have the ability to resistantly resist and yield to energy impacts arising from any cause or direction and that generally, will have for a member of a given mass, the inherent ability vof greater deformation when subjected to impacts and impulse loading and because of this ability, have larger resistance and absorptive capacity in each embodiment, member or component as well las in assemblies of components.
The advantageous use of prestressing preloads into the constructions of the invention provides very strong constructions having for their mass a much greater strength or having a smaller mass for equivalent strength. 'The resinous materials of the compositions used provide structural reinforcement both by their inherent strengths in tension, compression, shear'and torsion strengths and by the prestressed preloads induced into constructions wherein these advantageous materials in and of themselves provide force systems advantageously used in this invention to provide components of the invention. Not only is reinforcement provided by materials of the invention, but reinforcement is provided by a beneficial use of force systems.
Prestressing of preloads into embodiments of the invention is provided'iu :accordance with the disclosures and claims of my prior patents and are defined in these patents as mechanical means of prestressingl preloads, thermal means of prestressing preloads and chemical or phyisio-chemical means of prestressing preloads into embodiments of the invention. The means of prestressing may each be used alone, or may in various embodiments be used in combination of either, or in combination with chemical'prestressing means of the invention.
Among other devices used for control of traffic, precast concrete made of a commonly known mixture provided without the benefit of having reinforcing means as a part thereof have been used for traiiic control markers and devices, and have been found from extensive experience in their use, to be not too stable or resistant to breakage by vehicular traic. v
The liber glass and plastic resin composition laminated concrete bodies of my invention are an improvement over these unreinforced tratiic control markers :and devices when applied to such bodies. The combination of precast concrete of the conventional type of mix design with my laminated plastic resin ber reinforced constructions provides much improved and much stronger reinforced concrete bodies. However, inthe present invention further improvements are disclosed and claimed which provide long lived and permanent traflic control markers and devices of relatively low cost and having a permanent color built into the laminated materials which keeps bright and clear for easy recognition of the markers and devices in their several uses.
A study of the impact'loads to which street and road markers and devices are subjected, reveals impacts by moving cars and trucks which are multi-directional loadings dynamically applied at right angles to the marker in its longitudinal measurement, or at oblique angles to the marker, depending upon the location in its use, and the nature of the turning and travelling directions of the cars and trucks being controlled by the marker or devices. The construction of the marker or device requires resistance to loads which are ditlicult to measure and of varying intensity and input source, but experience and observation indicates that a basic requirement is not being met by reinforced concrete or the like presently made tratlic markers.
The crushing and shattering of existing markers and devices of this nature is evident and apparent on most any well travelled road or street using the same. The instant invention is directed to providing a construction pecularly adapted and particularly designed to provide a rubberconcrete and/or rubbery-elastomeric-concrete core body of the desired shape and cross section having a skinstressed laminated surface layer construction comprised of high strength polymeric resin composition adapted to resistance to dynamic loadings and impact-impulse loadings. The traiiic marker or device is usually bedded on a concrete or asphalt concrete road surface which bonding is found to be best accomplished by using an epoxy resin composition.
The marker shown in FIGURE l is made of a rubberconcrete body which is precast in a suitable mold and cured as in the manner of portland cement concrete. After drying in an oven or other means, a laminated layer 2l comprising a plastic resin composition 3 reinforced with fibrous strands 7, eg., fiber glass strands in the form of mat or woven roving or fabric, or strands of unidirectional iiber glass disposed in oriented directional placement are bonded and integrated to the rubber-concrete body with the stranded material placed to best resist impact loads coming to the marker from wheel impacts of moving vehicles. The reinforcing layer 21 is an enclosing layer on all sides and acts as does a jacket in containing the rubber-concrete core 10 but with a restraint that is greater than the compression strength of the rubber-concrete core 1i). The core ll) has by reason of the rubber content kof the concrete mixture a substantial tensile strength and compression strength. The core lil can be bent slightly and recover to original state, which property stands in good stead in the resistance of dynamic loading. The rubber-concrete is a resilient material, not brittle, but has a toughness due to the specially compounded and related mix design of the materials used to make core lil. Loads impacting the rubber-concrete are dissipated by reason of the cycle changes of the forces of impact in travelling through the rubber-concrete, it being found that rubber that is used has a substantially diiterent cyclic capacity than the portland cement and aggregates common to the cement concrete field. li scrap rubber obtained from cutting up old tires into finely divided particles is used, the reinforcing fibers used in the tires in their manufacture also are found to have still different rates of cyclic transmission of forces from impact loads which is an additional advantage in the composite materials of the mix design.
The portland cement and aggregates that are not of rubber, eg., stone, clay particles, lire expanded shale or clay, sand, silica particles or other stone-like materials 6 provide a low cost filler and body material and utilize their properties advantageously in resisting impact loads. The adjacent rubber particles 9 of the mix design having greater resilient capabilities provide the composite material with a bounce characteristic not found in known concrete materials including those having a rubber aggregate content as has been experimently tried in roadways. By reason of the laminated layer 21 having its bonding and integration accomplished by having portions of the rubbery polymeric resin composition 3 covering and encasing and bon-ding the fibers, eg., iiber glass fibers, which rubbery polymeric resin composition 3 extends into the pores and interstices connected therewith of the rubber-concrete core lil, it is found that the rein- C forcing layer 2i and its bonding and integrating extensions into the body of the rubber-concrete, provide a very strong yet very resilient bounce characteristic co-acting with the rubber core 10.
The resulting construction provided is tough, strong and highly resistant to impact. In making the polymeric resin composition binder and bonding material 3 a color is selected as a component thereof, e.g., white, or black, or red, or yellow, etc., which is a pigment comprised of a mineral stable to the use intended, particularly color stable and wear resistant and chemically inert to the binders of both polymeric resin and portland cement. Epoxy resins, polysuliide rubber resins, polyurethanes and polyester resins discretely used as is known in the art provide excellent binders. The high :compression strength of the composite materials of the rubber-concrete core and the skin-stressed laminated layer 2i has a capability with its high strength of being able to resiliently resist loading, in other words, has a substantially 100% plastic memory, rebound characteristics and bounce Component 7 of FIGURE 1 represents the fibrous reinforcement, e.g., fiber glass strands, or polyethylene terephthalate as made from ethylene glycol and terephthalic acid and provided as continuous filament yarns, or tine metallic wires, or synthetic bers, or inorganic or `organic iibers, etc., of which fiber glass for the present is preferred. Polypropylene bers and monoiilaments, or polyethylene filaments especially having black carbon like filler, or nylon, and/ or other thermoplastic filaments or sheets and films may be used in discrete combinations with liber glass for their color or for their structural characteristics.
If multi-colored embodiments of my invention are desired, integral color can be discretely provided, as black, or white or green, or red, etc.
The resin-ber integuinent 78 extending to and into the body of the core 10 is both a high strength bonding material as well as a tensile reinforcement at the interface of the plastic resin composition iiber glass layer and the rubber-concrete core 10. It too has resilient resistant features acting as would a rubber band to snugly draw the rubber-concrete core 10 toward the plastic resin composition fiber-glass reinforcing surface layer integument in resilient bond.
As a convenient means of setting such a trac marker and to obviate the need for chemical mixing of e.g., an epoxy resin composition bonding adhesive 4 at the site of use, I have found that the packaged-ready-for-use-products of my application Serial No. 340,642, filed January 16, 1953, and now Patent No. 2,951,006 and being adapted to the use of the instant invention, provide means for quickly and surely adhering a trafc marker of the invention to a concrete or asphalt-concrete road. Such an adhesive layer 4a is attached to the underside of the embodiment of FIGURE l at the factory and shipped to the site of use where a tear sheet of plastic lm is removed leaving exposed a sticky bonding layer which on application of means, e.g., pressure combined with internal catalyst means or curing agent means, sets the adhesive layer and thus bonds the marker device to the roadway surface.
The several features of disclosures and the claimed invention of my Serial No. 340,642, filed January 16, 1953, now Patent No. 2,951,006, are discretely adapted to this invention and provides means for using epoxy resin compositions and the like, which as used by unskilled personnel as is usually found in maintenance crews of highway and street maintenance departments, could cause injury or dermatitis because of the toxic nature'of some of the epoxy resin compositions, and the like, best suited as of the present state of the art for such binding and bonding materials.
Compartmentized envelope constructions as in my prior applications also provide bonding adhesive means wherein the compartments are internally opened prior to the opening of the surface exposingv the polymeric resin composition adhesive. Hardners are thus provided in one compartment and epoxy resins in another which when comingled and mixed in the enveloped construction provide for a rapid setting means ofadhesive bonding of the marker device to the roadway.
If such work is done in cold weather or under conditions where heat is a requirement of the bonding operation, the enveloped constructions of my Patent No. 2,671,158 as particularly adapted to this invention may be used.
Minerals like stainless steel dust, aluminum fines and powders, aluminum chips, and discrete particles of metals of suitable mesh sizes adapted to providing the faceted faces of the particles 23 provide functional decorative features. By selecting an upper range on Mohs scale of hardness of filler like commercially made A1203, aluminum oxide, the surface characteristics of the rubberconcrete core I0 is hard and in the bonded and integrated surface layer composition 21 is made most durable. The hardness of the iiller, in this case, about 8, protects the polymeric resin composition binder from abrasive Wear. Immediate effects of wear are not always noticeable. The filler mix must act in a structural manner and be able to stand differences of temperature and of expansion and contraction internally as well as loadings externally expressed, and these llers and resins provide such structure.
Depending upon the characteristics of the polymeric resin composition I cure such constructions as layer 21 in from 2 to 20 minutes and when I desire the maximum of structural considerations of design in strength I make sure by tests that I am not introducing internal strain and stress into the body of the lamination of the layer 21 so it may fail for this reason. The balanced design of filler, both bulk and fibrous, with the polymeric resin composition 3 is vital to good structural engineering design of the rubber-concrete laminated and bonded polymeric resin composition structure of the marker or device. I always prefer toughness to brittleness, even at the sacrifice of some of the tensile strength. A resilient structure is what I strive for and the instant invention is just such a structure.
The resin composition 3 which Iuse is advantageously one which thas substantial tensile strength and has a high shrinkage after preliminary setting for thosev embodiments of the instant invention which are made having a prestressed preloaded reinforcement means in the laminating layer 21, which resin composition 3 either should be one with extraordinarily high adhesive bond strength or should be so anchored and enmeshed in the porous structure of the rubber-concrete body that the shrinkage imposes and maintains the desired prestress on the rubberconcrete and in the surface layer 2i without pulling away from the surface of the rubber-concrete. T he resin composition which is anchored into the rubber-concrete may, with advantage, effect its major shrinkage before an overlying layer of resin. By permitting the rst application of a plastic resin composition tol the non-porous surface of a mold used to laminate the rubber-concrete core 10 to the and with the laminated layer 21, and allowing it to become somewhat of a gel and iirm, but not cured,y the plastic resin composition like an unsaturated polyester resin composition as disclosed in my patents of record, does effect its shrinkage in part depending how far toward the state of iinal cure the polymerization reaction is allowed to proceed before additional material is added. The polymerization or chemical setting reaction may be either by use of a faster setting resin (more catalyst or promoter as is known in the art) in the layer which impregnates the porous structure of the rubber-concrete, or the like, than in the overlying layer, or by applying the -impregnating layer in advance and pre-gelling it, so that `in its nal setting and high shrinkage period the layer of resin composition above it will still be sufficiently soft` so that it can be sucked down to accommodate itself to the shrinkage of the impregnating layer.
Advantageously, a thin layer at the surface which carries the color pigment in some cases, which is applied onto the face of the mold also is faster setting or applied and partially gelled in advance so that here also its shrinkage will be accommodated by flow of the still unset resin of an intermediate layer. When the intermediate layer docs set its shrinkage is imposed against both the surface layer and the impregnating layer so that both are reinforced against tensile stresses; and since it is this intermediate layer in the present example which ycarries the liber glass or other iiber reinforcement, it is most advantageous that it should thus carry the severe tensile stress. The liber reinforcement such as fiber glass mat 7, or the like, insulates the concrete body from the exterior portion of the resin for a time until the temperature of the polymeric resin composition, or the like, increases as the polymerization reaction progresses. There are other features inherent in the nature of plastic resin compositions Which provide features and characteristics of control in the structural uses of the force systems which they can provide or can capture as prestressed preloads.
Of particular importance to the instant invention I have found that by selecting a rubber resin composition for use as polymeric resin ofthe bonding layer of layer 21 shown at 3 in FIGURE l adjacent the face of the rubber-concrete core 10 of FIGURE l, which resin has capability of Welding or of being vulcanized to the rubber component 9 of the rubber-concrete, I have provided a very desirable construction in which the maximum features of bounce are provided. Continuity of resin composition 3 structure of the integrant 78 of FIGURE l is provided so that impact loadings are advantageously subjected to cyclic change from the exterior of the nished construction in their travel through the body `or" the core 10. The rubber-like, rubber band-like feature of component 78 linked in vulcanized bond to the rubber 9 of the rubber concrete provided amazing and unusual capabilities in dissipation of dynamic energy, it being found very difficult to fracture or damage the composite structure herein disclosed. Vulcanization of the surface layer construction embodiments to and with the rubber aggregates 9 of the rubber-concrete is easily accomplished in the manufacture of embodiments of the invention because the heat used to polymerize the polymeric resin compositions 3 of the laminated layer 21 also provides the heat used to vulcanize the polymeric resin composition or elastomeric composition bonding of the rubber aggregates of core 10. Compatability of the polymeric resin composition of bonding layer of layer 2l, and from which extend the integrants '78 of the same material as layer 3 is all that is required in the exercise of a vulcanization of the materials. This is to be had from several rubbers, rubbery polymeric resins, and elastomeric materials disclosed herein. In a sense this is a sandwichlike construction wherein the layers of the sandwiched materials provide specific properties.
In making such constructions I have observed plastic resins pass up Within live minutes or less, from a pan on a heated platen into a one and one-half inch thick concrete slab portion of a concrete block placed thereon, the block being preheated and dried before such use. In the instant invention, by controlling the porosity of the rubber-concrete mix design as a precast raw element for the marker I use such porosity to become a storage meansinside of the rubber-c-oncrete core t and fill this space provided by the pores and interstices connected therewith with a discrete polymeric resin composition. In the instant invention, I find that subjecting the core 10 or the core 12 or core 1d to a vacuum means While carrying on'the laminating and integrating process of the invention and by pulling out the air through the rubberconcrete body, the plastic resin polymeric resin composition can be and is drawn up into the body where it iills the pores, and in the process lof polymerization sets in the pores, iilling capillary spaces to make a unitary reinforcement Within the rubber-concrete structure of the body. Use of even a partial vacuum aids in making such reinforced structural bodies. Penetration and permeation induced by pressure exerted on the face of the still fluid plastic resin has a like result. T he amounts of pressure are elements of balanced design in securing the kind and type of integrated structure that is desired in any given construction. 'Iihis means is particularly advantageous when vulcanization of the integrants is accomplished because it is a sure means of providing predetermined amounts of integrant materials in the pores and interstices of the core lll or core l2 or core 14.
The resin used in my invention is advantageously liquid. It may be in various viscous states or may be a paste resin or even a powdered resin which in the processing becomes compatible with easy means of using, ie., by heating, melting, diluting with copolymerizable materials, by solvents incorporated into the resin composition, etc. The resin catalyst, such as benzoyl peroxide and other peroxides, persalts or hydroperoxides and for epoxy resins, dicyandiamide or phenylene diamines, or copolymerizable polysulde rubbers, rubber resins or polyamides, may also be liquid, paste or powder and may be incorporated directly into the resin in intimate mixture or can be in fusible or crushable capsules from which it is released or expelled by heat or pressure of the molding operation. Metallic catalyst may also be used. Various rays may be used as from penetration radiation.
Fillers, pigments and other ingredients may be used according to the ordinary principles of plastic compounding and special features of the instant invention require llers having a hardness and Wearing characteristic which I nd should for best results be in excess of the hardness and wearing features of the polymeric resin binders used in layer 21. I have found that a tough, rubbery polymeric resin composition having a high bonding strength is preferable to a hard brittle composition. By holding the lillers in position so that their superior Wearing abilities are available at the surface is found to be a preferred type of construction. Pulverized colored aggregates of silica, corundum, or aluminum silicate, eg., A1203 having a faceted face to the particles of aggregate provide reflective surface viewed through the polymeric resin composition and when the polymeric resin composition is ground off intentionally or by the ordinary wear of the marker in use, the faceted particles 23 provide a glint and glisten to the surface of the marker making it much more visible than when such a iiller characteristic is not found in the linished construction in use.
Generally, silica type fillers of material having from 4 to 9 on Mohs scale of mineral hardness provides excellent filler for my use in sizes of mesh not now used in plastic resin compounding. The mineralogical characteristics and crystal habit of the filler materials I use provide many new and interesting features of color, luminescence and especially useful in the invention. Some of the minerals embedded in the surface layer 2l, like quartz crystals, or other rock crystals by their faceted habit provide reflective surfaces when lighted by night illumination as from approaching headlights of cars or direct focused lights. As safety features these constructions as made by my invention are permanent constructions of highways, bridges, abutments, safety guards, roadway directive signs, markers and devices and the like. The addition of pearl like particles of sea shells makes a good reliective surfaces construction for embeddment in the plastic resin composition of the layer 2l.. Corundum particles are especially used against light or White backgrounds of plastic resin composition having such a White or colored filler, eg., White titanium pigment or yellow ochre pigment and have the advantage of being very hard, approaching 8.0 on Mohs scale of hardness for minerals. By polishing off the outermost resin surface lm and in some instances polishing the aggregate particles, l make extremely beautiful surface constructions having the most desired utility as safety markers and devices, etc.
Crushed abalone shells provide irridescence of the shell particles when used as ller in a clear resin of the invention. Glass beads embedded in the clear resin surface of the outer layer 21 makes reflective surfaces which refleet on-coming headlights of cars and trucks and are used in an approved safety manner.
Referring now to FIGURE 2, this ligure shows another embodiment of the invention wherein additional means are provided to resist impact loads and further strengthen the constructions of FlGURE 1 when used in combination with FIGURE l disclosures.
In pre-casting the porous structural body comprising core 12 of FGURE 2 a mold is provided having predetermined, sized and spaced cores located to provide holes in the finished precast core 12. These holes are for the purpose of holding a very strong reinforcement means 77 Which are disposed in the holes 17. These holes are placed at discrete angles to the faces of the marker device that is exposed to impact loading and are of a size designed to hold reinforcement rod-like members 77 comprised of fiber glass unidirectional strands embedded in polymeric resin composition providing a very strong column-like reinforcing means. These column-like reinforcements are designed close enough together to resist loadings of cars and trucks as impacted to the marker body.
ln the manufacture of the skin-stressed layers Similar to FIGURE l, in FlGURE 2 the holes 17 are filled with fibrous reinforcements 77, a unidirectionally stranded and embedded and covered fiber, eg., ber glass strands, which are embedded and covered with e.g., an epoxy resin composition having a polysulfide rubber resin as its hardner. Other resins that can be used with reinforcement 77 are polyester resins, polyurethane resins, epoxy-polyamide resins, etc., including various types of `these resin compositions peculiarly adapted to outside exposure under very rugged conditions as would prevail on streets and roads where markers such as FIGURE 2 would be used.
To provide a convenient means for manufacture, a mold, not shown, is provided which has the sized and spaced cores above described and the layer 2l built up in this mold starting with the outermost layer as described placed on the surface of the mold which may be done by pouring in the liquid resin composition or which may be done by spraying in such a resin composition. Conveniently, the packaged ready-for-use enveloped laminated layers, as provided in my copending application Serial No. 340,642, filed January 16, 1953, now Patent No. 2,951,006 are of the type that has a sufficiency of polymeric resin providing the surface layer 21 and the fibrous reinforcement 7 of the layer all preimpregnated and complete ready to be polymerized and cured in the mold. The filler, eg., aluminum silicate filler, a white crystal type of A1203 is provided mixed-in in the prepared packaged envelope member. Then on this preimpregnated layer a cured raw rubber-concrete component i2 is placed and the assembled materials in the mold is then placed on a heated platen of a platen press and compressed at a predetermined pressure for a predetermined time related to the curing cycle of the instant polymeric resin composition of the preimpregnated member layer. The reinforcements 77 are placed in the holes 17 prior to the placing of the core 12 into the mold in certain of my embodiments and in certain others the reinforcement 77 is placed in the holes at the time it is placed in the mold. If the polymeric resin composition 3 is thixotropic this condition aids in placement of the layer 21 as it allows little or no flow from the placed member. However, this does not preclude using a non-thixotropic polymeric resin composition as it can be handled by moving the mold into the horizontal position on rst one side and then the other in order to make an even layer. Obviously, the packaged-ready-for-use package envelope of my Serial No. 340,642, filed January 16, 1953,
l@ now Patent No. 2,951,006 is more convenient in many applications.
The mold is provided with' a specular face capable of providing the smooth surface desired in many of the embodiments. 1t may also be provided with a ribbed face or patterned face especially prepared to, provide the maximum view of the marker device by having eg., a serrated face or lined and grooved face providing angles of incidence for the light rays from car headlights to impinge with the greatest reflecting efficiency from the marker device. The mold may be made of stainless steel, aluminum either cast or sheet, fiber glass plastic resin composition, glass, enameled surfaces, or in fact any mold surface adapted to release a polymeric resin composition casting or laminate with or Without the aid of mold release substances suited to particular resin compositions as is known in the art.
The plastic resin composition embedded and embedding the liber glass strands or other type of fibrous reinforcement of the invention is advantageously a lled polymeric resin composition, eg., an epoxy resin having a discrete curing agent, e.g. Bakelite Brand epoxy resins ERL-2774, ERL-3794 and ERL-2795 as sold by Union Carbide Corporation, New York, N.Y., which epoxy resins are reactive, amber colored liquids which can be cured to a' solid, thermoset state by the addition of a catalyst or hardner. The chief differences between these resins can be found in their initial viscosity and in their performance after cure at elevated temperatures ERL-2795, the least viscous of the three resins, possess good handlingcharacteristics and performs well in room temperature applications. ERL-2774, which is more viscous, gives superior strength and electrical propertiesat elevated temperatures. Both resins exhibit good solvent resistance with ERL- 2774 being slightly superior. The third resin, ERL-3794. is quite similar in most respects to ERL-2774, but has a slightly higher viscosity. It is recommended for applications requiring extreme solvent resistance. The three resins also differ slightly in their speed of reactivity, ERL-3794 reacting the fastest and ERL-2795 the slowest.
The epoxy assay, gram per gram-mole epoxy for ERL- 2795 is 179-194; for ERL-2774 is 18S-200; for ERL- 3794 is 174-186, with the viscosity, cps. at 77 deg. F. being SOO-700; 11,000-14,000; and 12,000-19,000 respectively for the three resins. Reactive diluents such as butyl glycidyl ether or nonreactive diluents such as dibutyl phthalate may be blended with ERL-2774 and ERL- 3794 epoxy resins to reduce their viscosity. In the art it is known that granular fillers such as silica and calcium carbonate may be dispersed in these resins and curing agents to modify their consistency, reduce peak temperature reached during cure (curing mechanism is exothermic), and to increase thermal conductivity and reduce the thermal coefficient of expansion of the cured resin system. Fibrous llers such as chopped glass liber or steel wool may be added to increase strengthsand impact resistance. Epoxy resins offer outstanding resistance, e.g., chemical resistance, particularly caustic resistance, excellent strength and toughness.
Epoxy resins are cured by a variety of compounds containing active hydrogen or by catalyzed self-reaction. The materials in the variety of compounds containing active hydrogen, generally called hardners, coreact with the resin. Examples of the commonly used hardners are the primary and secondary Laliphatic and aromatic polyamines, acid anhydrides and two-step phenolic (novolac) resins. The second group, or catalysts, promote the self polymerization of the epoxy resin. Tertiary amines and boron trilluoride complexes are the most commonly used catalytic agents. 1
Primary and secondary aliphatic polyamines such as diethylene triamine are moderately low viscosity liquids which can be blended with the epoxy resins at room temperature. These hardners give a fairly complete cure at room temperature so that the application of heat is unnecessary. Preferably, however, a short post cure, of for example, two hours at 212-225 F. will improve the properties of the cured resin. Aliphatic amine cured epoxy resins are considered for use in their best qualities when used at temperatures below about 180 F. since their heat distortion point is about 212 F. Also care must be exercised in their use because excessive inhalation of vapors and contact with the skin and eyes is very irritating. Cured in the proper manner, these resin-hardner systems are generally non-irritating.
Modified aliphatic amine type hardners for epoxy resins such as Bakelite ZZL-0814 and ZZL-08l6 in their modification provide less irritating effects on the skin and provide simpler mixing ratios and a wide selection of pot lives, curing-rates and convenient working viscosities.
Primary and secondary aromatic polyamines used as hardners for epoxy resins offer better elevated temperature strength and electrical properties than aliphatic amine type hardners, longer pot lives and very superior chemical and solvent resistance. While such aromatic polyamines as p,p'-methylene dianiline, m-phenylene diamine and diaminodiphenyl sulfone are solids at room temperature, these hardners can be dispersed in the resin at room temperature and the system heated to eiect solution or these hardners can be melted at 1Z0-140 F. and added to a heated resin. Eutectic blends of p,p'methylene dianiline and m'-phenylene diamine, which are super-cooled liquids at room temperature, can also be formed; these eutectics can be blended with the epoxy resin at room temperature.
Elevated temperatures are required to both gel and post sure aromatic amine hardened systems. In addition, a catalyst, such as one percent of boron trifluoride monoethylamine is normally used in diaminodiphenyl sulfone hardened systemsl to avoid the otherwise necessary long post cures. The p,pmethylene dianiline and m-phenylene diamine are quite similar in properties, except that m'- phenylene diamine tends to stain skin and clothing on contact. When used with ERL-2774, these two hardeners will give castings with heat distortion points of approximately 300 Fahrenheit. The diaminodiphenyl sulfone will give a somewhat higher heat distortion point, approximately 350 F., under similar conditions.
, Acid anhydrides are available in several types oiering a broad range of handling characteristics and properties in the cured resin systems, particularly in giving longer fpot lives, excellent adhesion, good electrical properties, and the possibility of formulating highly filled epoxy resin systems. Some ot the anhydride type hardners are hexahydrophthalic anhydride, phthalic anhydride and chlorendric anhydride. Elevated temperatures are required both to gel and post cure anhydride hardened systems. A small amount of a tertiary amine such as eg., 0.1- 0.5 percent of alpha-rnethylbenzyldimethylamine (Bakelite ZZL-0825) can be used to speed and direct the curing reaction.
At least one anhydride is a liquid which can be blended with liquid epoxy resins at room temperature. It has potentials of unusually long pot lives of two weeks or more at room temperature` The .properties of the cured resin system vary with the cure cycle employed. Using ERL-2774 castings with heat distortion points of 240 F. or more can be obtained.
Hexahydrophthalic anhydride has a low melting point (9S-97 deg. F.) and can be dissolved in liquid epoxy resins with only moderate warming; it does not crystallize out of the resin system when cooled to room temperature. It gives pot lives at room temperature in excess of seven days with good properties. ERL-2774 epoxy resin cured with hexahydrophthalic anhydride systems give castings with a heat distortion temperature of approximately 240 deg. F. l Y
Phthalic anhydride is a solid at room temperature coming in la iiake form. It can be dispersed in the liquid epoxy resins and the system heated to about 250 F.,
l2 to eleot solution; it will crystallize ou't of solution if the system is allowed to cool before it gels. Phthalic anhydride hardened epoxy resin systems exhibit good properties and have heat distortion points of about 300 F. in castings using eg., ERL-2774 Bakelite epoxy resin.
Low ammability of epoxy resin systems is obtained by using chlorendric anhydride which is much like phthalic anhydride in its handling properties. Chlorendric anhydride is a solid at room temperature and must be dissolved in the epoxy resin at about 260 F., to effect solution. lt will crystallize out of the system if allowed to cool before it gels. Chlorendric anhydride gives higher heat distortion points to about 390 F.
Two-step phenolic resin (novolacs) which do not contain water can also be used as hardeners for epoxy resins. They are solids `and they cannot be blended directly with the liquid epoxy resins at room temperature. Casting systems containing low molecular weight novolac hardeners such as Bakelite ERZ-754l are prepared by dissolving the novolac in the epoxy resin at an elevated temperature. Novolacs of a greater molecular weight range may be used as hardeners in epoxy laminating varnishes. Since these compositions are composed ot' epoxy resin and novolac hardeners in solvent solution, they can be handled at room temperature and may contain small amounts of tertiary amine catalysts such as Bakelite ZZL-0285 and are cured at elevated temperatures.
Flexible hardeners of especial interest in this invention have properties that provide somewhat iiexible cured epoxy resin systems exhibiting high impact and thermal shock resistance. They have been used for facing drop hammer dies. In addition to offering protection from mechanical shock, these exible systems readily yield to internal stresses and strains normally set up by thermal cycling. These systems provide the advantages of greater shock resistance and flexibility by reducing the degree of resin cross-linking. Ultimate mechanical strength, electrical properties are somewhat -lower than the cured rigid epoxy systems.
Examples of flexible hardeners are polyamide resins produced by General Mills, Inc., a hardener produced by Armour and Company, the liquid polysuliide polymers produced by Thiokol Chemical Corporation, a lling compound (not -actually a hardener) produced by Minnesota Mining and Manufacturing Company and the blends of fatty acid dimers and trimers produced by Emery Industries, Inc., with most of these materials being made in several gnades. The lower viscosity hardeners of the polyamides resins are convenient to handle because they can be blended with the liquid epoxy resins and cured at room temperatures. However, mild elevated tempera.- tures cures may be employed to quickly develop optimum properties.
Certain hardeners are .liquids or pastes at room temperatures, depending on the type. The prastes are dissolved in the liquid resins at moderately elevated temperatures. These resin hardener solutions tend to have low viscosities when cooled to room temperature. Mild elevated temperature post cures are usually employed to obtain optimum properties. Certain hardeners should be stored in closed containers so that they do not absorb moisture and gases from the air.
The polysultide liquid polymers are used in conjunction with tertiary amine catalysts such as DMPlO and DMP- 30 as offered by Rohm & Haas Company, or by use of aliphatic amine hardeners. Many of these systems which are usually low in viscosity, will cure at room temperature although cure at an elevated temperature may be used with slow catalysts having a long pot life and which develop optimum properties.
The fatty acid dimer and trimer blends are viscous at room temperature. They are usually mixed with the epoxy resin, gelled, and post cured at elevated temperatures. Tertiary amine catalysts with fatty acid hardeners are recommended to accelerate the cure.
"i3 Known filling compounds Iare not hardeners, but contain reactive epoxide groups which react with the hardener employed in the same manner as -the `epoxy resins. In substitming these known filling compounds for a portion of the epoxy resin, toughness is imparted to the resin system by virtue of its plasticizing action. These known compounds tend to give low mix viscosities and also permit the use of a wide range of hardeners.
Epoxy resins can yalso be self polymerized by the addition of catalysts. Catalytic curing agents offer a broad range of pot lives depending on the types and concentrations employed. Unlike the hardeners which must be used in strict stoichiometric ratios, the concentrations of catalysts used may be varied within certain ranges to control pot lives and cure rates.
The catalysts commonly employed with epoxy resins are divided into acidic and alkaline types. The common example of acidic type catalysts are the boron tritiouride amine complexes as offered by the General Chemical Division of Allied Chemical and Dye Corporation and the Harshaw Chemical Company, an example of which is boron triiiuoride monoethylamine. These complexes have only limited activity at room temperature, thus permitting the preparation of one package systems of epoxy resins and catalyst which may have a pot life of several weeks at room temperature. At elevated temperatures, these complexes quickly cure the resin. Heat distortion points of 320 F. can be easily achieved in e.g., ERL-2774 cat-alyzed with boron triflouride monoethylarnine castings.
The tertiary amines are the most commonly used alkaline type catalysts. Examples of tertiary amine catalysts used as curing agents for epoxy resins are triethylamine, diethylamine, propylamine, dimethylaminomethyl phenol (DMP-), trimethylarninomethyl phenol (DMP-30) and alpha-methylbenzyldimethylamine (Bakelite ZZL- 0825). These tertiary amines feature longer pot lives at room temperature than most primary alphatic amines. When used in proper concentrations, they will gel epoxy resins at room temperature. However, mild elevated ternpenature post cures are usually employed to develop optimum properties. Typical tertiary amine-cured ERL-2774 castings have good room temperature properties, and heat distortion points similar to those obtained with the alphatic amine hardeners. The epoxy technical bulletin No. 4 from Union Carbide Plastics Company supplied this information and further details can be had from thisbulletin.
The epoxy resins manufactured by Shell Chemical Company, Ciba Company, Inc., Bakelite Company, and others are based upon the epoxy resins synthetized by Pierre Castan in Switzerland land S. O. Greenlee in the United States in the late 1930s. Since 1952 such resins have been readily available and are in a constant state of commercial development and improvement, particularly with respect to hardeners, diluents and copolymerizable substances and i-t is the intention of this invention to use all such improvements in carrying out the principles of this invention.
Referring again to FIGURE 2, the specular faced mold, or other type of mold as then being used is filled with a layer of pigmented polymeric resin composition 3, eg., an epoxy resin composition having a polyamine curing agent as above described, but not limited to this one type of composition as several as are known in the art can provide the required features being sought in the finished product. The layer of resin composition may be pigmented black, or white, or green or red, etc., as required and may have a filler therefor comprised of hard, quartz particles or corundum particles 23, which when exposed by initial wear of the surface of the marker of FIGURE 2, have the said particles illuminated by the glint feature provided by them in their faceted particle faces. These particles are distinct crystal like particles, eg., passing a 1/a of an inch mesh screen and being retained on a mesh Tyler screen. Particle size is important because fines below 30 or 60 meshdo not provide enough faceted surfaces to reflect the light of on coming cars Into this layer of filled polymeric resin composition is placed a plurality of fiber glass reinforcing fibers in the form of a multi-directional mat on top of which are placed a plurality of unidirectional fibers of fiber glass fibers and strands located in directions of resistance to the impact loads expected to be resisted by the marker in its use. The strands may be woven roving of 60 ends l50s glass fibers and may have the warp rovings the. same diameter as the Woof rovings or 30 end roving and 60 end roving may be advantageously located to provide a warp or a Woof of the woven material having greater strength in one direction than in the other. The woven material may have stainless steel wire woven into it to provide a highly visible lined structure reflective of on coming headlights of cars and trucks.
With the surface layer reinforcement in place in the resin composition it is allowed to settle into the resin composition until it is well wet out and a surface showing a surplus of resin composition lies above the reinforcement. This is important because this surplus resin composition isthe resin comprising the integrant 78 and is provided in a predetermined amount directed to t-e amount and degree of impregnation required in any given embodiment. Also the surplus resin in some embodiments, is a different resin composition compatible in bonded structure with the first applied layer, but providing features such as rubbery bonded strength to and into the pores structure of the precast rubber-concrete element 12.
A particularly highly visible embodiment of FGURE 5 comprises an embodiment of crystal reflectors 55 of about l" in diameter bonded to the ends of the reinforcing elements 77 so that a pattern of brilliant retiectors is seen in the surface of the marker. The reflectors may project a small amount to increase their visibleness or they may be iiush with the top surface. lf the marker is used at a location requiring further warning to drivers, the reiiecting medium may be lighted from within the element 77 which in this case would be a hollow column or conduit 79 providing both supporting structural characteristics as well as providing means through which to carry electric Wiring 81 connected to such a light source.
Another means of providing an active illumination source of light within the marker is to provide electric lamps of discrete size and wattage in a socketed electrical device $2 known in the art and place this plurality of lights so that the lens 55 of device 82 projects slightly above the surface of the said traliic marker shown in FIGURE 5. Another means of providing an active and magnifying light means may be done by using an electric light or other illuminating means below a transparent layer of fiber glass reinforced polymeric resin composition, much like a lens not shown, which in use, would not only transmit the light but would also magnify it.
In FIGURE 2 the lens portion of the face of the marker device can be made concavely integral with the layer 21 or it can be made as a removable portion of layer 21 fastened to the marker by means.
Another means of providing active illumination to the marker is to allow the reinforcements 77 to project above the surface of the marker a discrete distance and have as their surface light reflecting media, as crystals 23, or glass beads 33, which reinforcements 77 could be removable when worn down and replaced by new ones.
-If Plexiglas, a known methyl methacrylic resin (refer to Condensed Chemical Dictionary, fifth edition, page 874, col. 1) is used for this reinforcement, vor at least the top portion of it being of Plexiglas and which is connected to a source of light within the embodiment of FIGURE 2, the light may be piped through the Plexiglas, a known methyl methacrylic resin.
FIGURE 3 illustrates another embodiment of the invention wherein a shallow depth rounded face member is provided which advantageously can be set about flush with the street or roadway surface so as to offer very little obstruction to car and truck wheels going over it. The shallow type of embodiment of FIGURE 3 also has resistance to impact loadings because it offers less surface for such impacts. However, it is not as visible from a distance as is the embodiment of FIGURES 1 and 2.
The polymeric resin composition 3 of layer Z1 is a reinforced plastic resin composition having a discrete iiller therefor which filler is selected for its crystal faceted characteristics which reiiect light from on coming headlights of cars and in this case is preferably corundum crystals of black or white corundum of large mesh size eg., 3/16 to 1/s which is disposed against a white titanium filler in anV epoxy resin composition. The black or white corundum is placed at the surface and if desired, may be distributed over the face of the embodiment of FGURE 3 after the element is made so as to be sure that the black corundum lies in a plane of view to catch light from on coming headlights of cars and trucks and make the marker very noticeable. The reverse light catching media can be used in that a black background pigmented resin may support on its surface similar White particles of faceted aggregate as eg., white corundum, glass beads particles or other reiiective media of a permanent nature or white background having white crystal-like particles as its reective media.
The material 14 comprising the core of the embodiment of FIGURE 3 is Vadvantageously made of a rubber-concrete which has substantial elasticity and bounce Such a rubber-concrete is made by using rubber aggregate particles 9 in the plastic concrete mix in much the same manner as stone aggregate is used. Ground up and chopped up used tires are one source providing such rubber aggregate in the terms of this invention. The plastic concrete is comprised of portland cement, white or natural colored silica sand and the rubber aggregate and is placed and cured in the above mentioned molds and set and cured like conventional concrete. An improved rubber concrete is provided in this invention by impregnating substantially all of the Way through an embodiment 14 Vwith a rubbery-elastomeric resin composition which fills the pores and interstices therewith in advantageous manner to provide a bonded elastomeric adhesively bonded structure. The resiliency of such a rubber-concrete is adjustable by the mix design wherein relative amounts of rubber aggregateto sand is used and by the amount of porosity provided in the resulting element 14 and in the impregnation of these pores thus created by an elastomeric rubbery resin composition which is adhesively bonded to the rubber aggregate of the rubber-concrete concrete. A polysulde rubber epoxy resin composition having the design of the mixture balanced on the side of rubbery characteristics is one resin composition among several that may be used. The rubber aggregate may have and does have rubber particles in sized aggregate portions so that the internal structure is lstrong yet has suiicient porosity to provide space for the integrant polysulfide rubbery epoxy resin composition. Such porosity advantageously as in the range from 5% porosity to 30% providing storage space in the cellular structure of the core ld.
Other elastomeric rubbery resin compositions can be used among which is neoprene rubber, used as aggregate rubber particles is impregnated with epoxy resin having iiexibilizing modifiers such as a polyamides resin. The ratio of such a rubber resin eg., per 100 parts epoxy resin with 67 parts polyamides resin provides a tensile strength of 7,800 p.s.i. and an elongation factor of 7% is obtained While at 100 parts of epoxy resin with 100 parts of polyamide resin a tensile strength of 2,500 p.'s.i. is provided and an elongation factor of 92% is obtained. By
applying structural engineering design to such a problem in materials design, it is possible to provide a wide range of CFI pas
tensile strengths and related elongation factors and in balanced engineered designed basis.
FIGURE 6 illustrates an isometric view of a traiiic control device and marker having an integral heating means 39 which melts snow and ice from the marker and insures that the marker is always visible when freezing rain or snow obscures the road surface. The heating device comprises a resi-stance wire circuit providing heat from an electricity source 33. The circuit of resistance wires 39 is connected to an outlet box of the waterproof type 38 which is connected to a central box 37 by means of a conduit and wire circuit to a thermal actuating switch 35 which is turned on and off by differences in ambient temperature on an automatic basis. The skin-stressed surface of the traflic control device is similar as in FIG- URE 1.
The following examples are illustrative of the invention and are not to be taken as limiting of the invention disclosed herein.
Example I Since the average road or highway may have its surface coated with oil from Vehicles, an oil resisting material is advantageous as a binder in making rubber-concrete. lt is known that marked resistance is shown by a reaction product of ethyiene dichloride and calcium polysultide, and by ThiokoL a polymethylene polysuliide. Vulcanization of such materials can be carried on in the same manner as rubber but requiring no sulfur, but by using zinc oxide in proportions by weight of from one to twenty percent. Such rubber-resin is similar to rubber (natural) being homogeneous and pliable and with a specific gravity of eg., 1.6. The suitable vulcanization temperatures are similar to natural rubber mixtures in mixings such as one hour at forty pounds steam pressure. if milling is desired facilitated about five percent of natural rubber can be added, but care should be taken to avoid too much natural rubber as oil resistant features are deteriorated by it. Adding carbon black will increase the tensile strength of the product and will decrease porosity. A mix of the following will give a very oil resistant product:
Parts by weight A reaction product of ethylene dichloride and calcium polysuliide 20 Pale crepe rubber l Zinc oxide 2 Carbon black 5 This material is cured and comminutcd to size desired and becomes an aggregate particle material for use in a concrete-rubber mix.
It is also known that e. g., 750 grams of hydrated sodium suliide (Na2S-9H2O) is dissolved in approximately a liter of Water and the solution is boiled with 300 grams of sulfur to produce a solution of polysulfide believed to be largely Na2S4, although a certain amount of Na2S5 is doubtless formed. If larger amounts of sulfur are` used in this example, still greater proportions of Na2S5 will be formed.
Water is added to make the specific gravity at 70 C. approximately that of ethylene dichloride producing about 1200 to 1300 cc. of solution. About 300 cc. of ethylene dichloride are added and the mixture gradually heated to about 70 C., preferably in a vessel having a reflux condenser. The reaction proceeds rapidly and is completed after digesting for an hour or more at such a temperature that active reiluxing of the ethylene dichloride and steam occurs. The mixture is then cooled and the liquid portion is drawn off, leaving a yellow plastic. This is boiled with Water to drive off occluded volatile compounds and to extract soluble salts, the boiling preferably being repeated several times, and the plastic being comminuted between boilings. The purified plastic is substantially free from halogen, is of high coherence, resiliency and pliability, and has elasticity somewhat similar 17 to that of soft rubber. It is only slightly soluble in most ordinary organic solvents, although somewhat swollen by carbon disulfide. It can be worked molded and rolled into sheets at temperatures around 130-140 C. As comminuted particles of plastic material after washing, such particles can provide the rubber aggregate particles of a rubber-concrete, which may be dusted for handling.
A rubber-concrete mix is illustrated by the following, but because of the many rubber-like resinous compounds available for such use, such a mix is not limiting of the invention, as many more can be provided from known materials.
Parts by weight Portland cement l Silica sand-JA@ mesh to fines 27 Aluminum silicate-325 mesh Fire expanded shale-1A" mesh 18 Rubber aggregate particles Water to make a dry mix.
The silica sand and the fire expanded shale can be increased to about 35 parts of silica sand and the fire vexpanded shale can be to about 38 parts by weight with the rubber particles being reduced to about 32 parts by Weight. Since the surface characteristics and wetting features of silica sand and the other minerals vary such a mix must be worked with to provide the right balance required of the specific -materials being used. Also the degree of rubbery characteristics is controllable by the relationship of the rubber aggregate particles to the balance of the mix. An increase in portland cement Will tend to reduce the number and size pores and the pore structure must be related to the amount of integrant that is desired. However, such a rubber-concrete has the capability of being vulcanized or of being adhesivelyv bonded by compatible rubber resins. p
Another means of providing a rubber concentrate or rubber content to a rubber-concrete mixture advantageously, is by providing granules or particles of lire expanded shale or clay passing a Ss" screen and retained on a 1/16" screen which granules or particles are covered With a latex and the particles and granules tumbled and dried so that each one of them has a layer of rubber enclosing it. This rubber covered aggregate is then used in the known manner of making a concrete but has this advantage, in that the predetermined amount of resilient material can be easily determined by the thickness of the covering encasing the granules or particles. lf a porous aggregate is supplied such as a volcanic cinder, or tufa, or coral rock, etc., the internal structure of the porous aggregate can be filled making a composite structure out ofthe aggregate before it is used to make concrete.
Comminuted particles of used rubber, eg., used tires can also be used for rubber aggregate. These particles can be dipped in a latex and tumbled in a sand and/ or dry portland cement mix and provide an easily handled aggregate adapted to being mixed in a concrete mixer without having to clean the mixer with solvents.
In making a rubber-concrete core l0 of the invention, it is important to consider the amount of pores and interstices in the core material so it has a pore structure related to the structural engineering materials requirements than being provided for. A pop-corn type of concrete-rubber mix with its large amount of cellular space provides a very resilient body to the core when it is impregnated and laminated as herein disclosed. A dense type` of rubber-concrete-rnix obviously affords less resiliency and greater compressive strength, but both type of mixes provide amazing impact resistance and dissipate dynamic loading better than even a pumice concrete.
The term rubber used herein includes any resinous rubbery material of natural rubber of commerce, or any synthetic rubber or rubber resin useful in the disclosures of this inveniton. The term Portland cement includes cement made by the manufacturers represented by the Portland Cement Association and includes special cements .that are resistant totemperature and chemicals of a specific nature. The term concrete is clearly defined in the Concrete Manual by the Bureau of Reclamation of the Department of the rinterior of the VUnited States.
Example I1 The following formulation provides one example among several of an unsaturated polyester resin composition 'adapted to an embodiment of the invention:
Parts by' weight Rigid type unsaturated polyester resin 3178 Faceted crystal silica-balanced mix of: l
30%, 60 mesh; 30%, 30 mesh; 20%, 16 mesh;
20%, No. 4 mesh 2724 Glass beads A 908 The rigid and flexible unsaturated polyester resins are placed in a mixing vessel, e.g., a change can mixer, and the benzoyl peroxide is added dispersed in styrene monomer equal to about 200 parts by Weight. The resins and the catalyst benzoyl peroxide are thoroughly mixed. Next add the milled fiber glass, aluminum silicate,titanium dioxide pigment, silica particles, glass beads in that order and continue mixing for about one hour or until the formulation is thoroughly mixed. Use care in mixing so as not to entrain air in the mix.
Whenthe formulation is ready, clean, Wax and coat vwith mold release the molds of the shape of FIG-URE l or of the shape of FlGURE 4, or otherwise, and cover the specular faces of the mold with about 1/s inch thick layer of the 'above formulation and vibrate the mold or otherwise provide means to settle the silica tiller'and glass beads towards the specular face-of the mold to make them visible in the face of the product. On this layer place a layer of ber glass mat reinforcement eg., 6010- Woven roving, or eg., 2 oz. multi-directional fiberglass mat, or e.g., a surfacing veil of ne spun glass ber and a 1.5 ox. fiber glass mat, and if mere strength is desired in the reinforcement of the layer', use multiple layers of the above as desired. Wet the fiberglass thoroughly by having the formulation liquids penetrate'and permeate the fiberglass mats and provide a surplus thereover in the quantity of formulation desired forv integrant penetrated and permeated into the core body 10.
When the fiberglass is thus prepared, place a rubberconcrete core body in a dry condition on the face of the formulated layer and then place the assembled materials in the mold in a vacuum chamber or device and pull a vacuum in sufficient amount to draw the surplus polyester resin composition into the pore structure of the rubberconcrete core body and substantially fill these pores. Either while still under vacuum or after withdrawal from the vacuum chamber of device, next place the mold and its contents on a heated platen press and press to consolidate the materials and cure at a predetermined .ternerature for a predetermined time, which, e.g., maybe I surface is had.
When readyy for use, place a prepared, packaged and Y 19 ready-for-use pre-impregnated epoxy rcsin-sand-tiberglass bonding mat on the bottom of the marker device on the core face and adhere with a sticky holding means, e.g., the epoxy resin composition, the bonding mat, the inside cover of which is removed in such placement and the outer cover left intact until ready for use on site. Such a preimpregnated bonding mat is disclosed and claimed in my Serial No. 340,642, led January 16, 195.3, now Patent No. 2,951,006, and the reel-unit thereof advantageously used as shown therein.
Alternatively, the marker as made in the above mold may be shipped to the site of use and a reel-unit having a iibrous plastic resin reinforcement adapted to adhere and reinforce the marker when in place in use, is provided and in use is unreeled and the mat covered with the bonding resin provided in the reel-unit and a quantity of the bonding resin is placed on the roadway or` street in place to be under the marker device as placed. In this way several markers can be placed in -a row and one bonding layer 47 provided for the row. The resin thus used is advantageously one that will cure and set at ambient temperature and preferably be a resin composition not aiieoted by water in its set. This embodiment o'f the invention has an advantage in that the continuous reinforcing layer on the roadway bonding the markers to the roadway surface Vprovides reinforcement resistive for markers one to the other and distributes impacts more. readily.
Example III The rubber-concrete marker 1t) is precast with a series n marker is then covered with a surface mat reinforcing embedded in a polymeric resin composition having a line silica filler, eg., 250 mesh and a corundurn filler eg., 60 mesh Tyler screen to 16 mesh Tyler Yscreen black corundum having distinct faceted crystal structure. The corundum can be white or any other discrete selected color having a distinct Vfaceted crystal structure.
Advantageously, on a partially cured epoxy resin composition on the surface of a marker of the invention, glass beads 83 or other high light reflecting media 23, are placed on the epoxy resin surface and adhered thereto. The glass beads are sprayed on the surface so that as much open surface of the beads vis available for reflecting light from headlights of on-coming cars and trucks. marker is Weathered or dulled by impacts, such glass beads 83 can be re-applied in epoxy resin composition which bonds readily to the marker. Y
As the instant Itis recognized that while the instant invention has been 'described and is claimed for the benecial improvements provided to"traflic markers and devices, the principles of this invention are not limited to only these embodiments of invention, lbut on the contrary, are recognized Vas being beneficial improvementsin other structural load bearing constructions wherein rubber-concrete plastic-resin composition reinforced structures have a place of um Although some of the embodiments and examples Vset forth herein are substantiallyV identical with, those Vgiven in companion cases covering related but distinct inventions, it will'be readilyV understood lby those versed in the'iart Vof patent law and practice that this is because these practical articles and methods embody in- 2() together may be considered optional or can be replaced by'alternatives.
The exampies andv alternatives given should not be regarded as exhaustive or` limiting of the invention but, on the contrary, are given for the purposes of instructing others in the best manner of using and applying the inventions and so far as to explain and illustrate the principles thereof that others will be enabled to use the inventions in many forms, modiiications and various embodiments, cach as may be best adapted to the requirements of a particular use.
While certain preferred embodiments of this invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.
Having described the invention, what is claimed as new is:
l. A traffic control marker secured to a road surface comprising a porous supporting core, said core comprising a mixture of concrete and rubber, particles, and a composite stressed skin layer disposed about said core, said skin layer comprising a resilient polymeric resin with at least a portion of said core being penetrated and permeated and integrally bonded by said resin, and a fibrous reinforcement coextensive with said core and embedded in said resilient resin, and fillers and pigments disposed in said resin layer, said particles of llers comprise hard, faceted particles providing light redective surfaces to light striking said surfaces from headlights of moving vehicles and providing warning and traic control.
2. A trailic control marker as in claim l wherein said surfacing-skin-layer is white in color with alternated pigmented contrasting color, said combination of colors adapted to traffic control and being provided in a high visibility arrangement.
3. A traffic control marker as in claim l wherein said filler comprises faceted made particles having a hardness on Mohs scale of from 4 to l0'.
4. A trafc control marker as in claim 1 wherein said ller includes discrete reliective glass beads.
5. A trahie control marker as in claim l, in which said core is a precast, preformed body which has spaced and oriented holes through said body and berglass polymericsresin-column-like-reinforcements disposed in said holes in resilient polymeric resin bond to and with said body and said hbergiass-polymeric-resin-column- Vlike-reinforcements having the capability of providing substantial resistance to energy impacts from moving vehicular trafiic vehicles.
6. A trafc control marker as in claim 5, in which said column-like-reinforcernents comprise hollow tubes having at their exposed ends retiectors and illuminating means connected thereto. said reiiectors and illuminating means being clearly visible from a distance.
.7. A trahc control marker as in claim l, in which said core is a rounded shallow depth body and eJ bedded in and set substantially iiush with a roadway surface providing only the reflective suriace of the rounded portion projecting above the roadway surface.
8. A traffic control marker as in claim l, in which in addition, a heating means is embedded in the said core providing heat to melt ice and snow from the surface of said marker, said heating means connected to an electrical device automatically operative by temperature changes and turning on said heater at a discrete vendons, each or some of which can be used with on Without the others, Le., some of the inventions thus low temperature and turning ofi said heater at a discrete higher temperature.
9. A traffic control marker as in claim l, in which Ysaid iiller is selected from the group consisting of faceted silica particles, faceted corundum particles, and faceted metal particles. v
l0. A trafiic control marker as in claim l, in which 21 Z2 the core material comprises Portland cement, silica sand, References Cited in the file of this patent and ground-up rubber particles.
11. A traic control marker as in claim 1, in which UNITED STATES PATENTS the said core comprises Portland cement, sand, and rub- 135400 Johnson NOV- 1: 1938 ber-covered-aggregate-particles. 5 2,413,990 MUUZ Jal1- 7, 1947 12. A trafc control marker as in claim 1, in which 2,425,883 JaCkSOIl Allg. 19, 1947 said polymeric resin composition comprises a member 2,664,406 Armstrong Dec. 29, 1953 of the group consisting of unsaturated polyester resins, 2,776,914 Faulwetter Jan. 8, 1957 epoxy resins, and polyurethane resins. 2,851,935 Weeks sept. 16, 195s 13. A traic control marker as in claim 1, in which 10 2,870,793 Bailey Jan' 27, 1959 said fibrous reinforcements comprise inorganic strands. 2,942,853 Glaros June 28I 1960 14. A trac control marker as 1n cla1m 1, 1n wlnch 2,979,307 Grone Apr. 11y 1961 said fibrous reinforcements comprise organic strands.
15. A traic control marker as in claim 1, in which said reinforcements include metallic Wires. 15
3,049,980 Gill Aug. 2l, 1962