US 3317189 A
Description (OCR text may contain errors)
y 2, 1967 D. RUBENSTEIN 3,317,189
TRAFFIC CONTROL BUMPER GUARD RAIL STRUCTURES Original Filed Aug. 19, 1960 United States Patent G 3 Claims. (Cl. 256-131) This invention patent application is a divisional application from my copending patent application Ser. No. 50,767, filed Aug. 19, 1960, a portion of which is now Patent No. 3,164,071.
This invention relates to improvements in traflic guard structures and devices for streets, roads, highways, freeways, expressways, airfields, and to methods for making the same.
An object of the invention is to provide-mass-produced, durable, long-lasting, relatively maintenance free trafiic guard structures and devices.
Another object of this invention is to provide trafiic guard structures and devices having permanently colored surface layer constructions of white, black, red, green, yellow, amber or in fact any other color useful and used in traflic control devices.
Another object of the invention is to provide trafiic guard structures and devices having reinforcing means that are resilient and particularly adapted to being resistant to impact and crushing from loads imposed by moving vehicles, cars or trucks.
Another object of the invention is to provide traflic guard structures and devices useful under all weather conditions while having maximum visibility.
Another object of the invention is to provide trafiic guard structures and devices having included in their construction means adapted to melt snow and ice so as to have such structures always exposed to view.
Another object of this invention is to provide trafiic guard structures and devices having included in their construction surface components of their surface construction layer providing color and luminescent particles, or particles and pigments, or reflective materials, that are decorative or functional and fixed for daylight or for night illumination.
Another object of this invention is to provide traflic guard structures and devices having illuminating sources of light in their make-up and operative by automatic means and controls.
The extensive development of the nations highways, roads, freeways, and expressways has brought out the need for more efiicient means and devices to control traffic and with more safety. The use of traflic guard constructions has been occasioned with substantial amounts of painting and maintenance costs. Particularly, colors used in paint on traffic guard constructions do not live well and require constant replacement.
In the drawings herewith provided I have shown preferred embodiments of my invention, and have described the same and modifications 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 illustration of 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.
3,317,189 Patented May 2, 1967 In the drawings:
FIGURE 1 is an isometric view of a traffic guard construction comprising a portion of a highway acting as its curb.
FIGURE 2 is an isometric view of a trafiic guard having stressed surface construction layer and self contained illumination means.
FIGURE 3 is an isometric view of another embodiment of the invention.
The rubber-concrete core-bodies and laminated surface layers thereof provide laminated construct-ions having resiliency and compressibility stress and strain relieving capacity that is rubber-like. Such a construction provides articulation and movement between laminated members as well as surface articulation movement abilities of stretch, tension, compression, torsion, twist, and shear. This generally provides flexible movements without separation of the members of the laminate, or separation or failure from the concrete or rubber-concrete or porous structural material. The resulting production has the resilient properties desired in embodiments of this invention and Within the designed limits of stress and strain of the lamination.
The advantageous use of prestressing preloads into the constructions of the inventions 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. 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 the materials of the invention, e.-g., the polymeric resins of the invention, but reinforcement is provided by a beneficial use of force systems.
The trafiic guard structure shown in the figures is made of a rubber-concrete body. Such a body is broadly defined by the term rubber-concrete to include any resinbound, elastomeric material bound, composite compatible resinous, rubber or rubbery bound material disclosed herein. This may be a precast material or may be an integrated composite surface construction layer having a core material integrated continuously into the desired structure made in continuous process means.
The traflic guard structure is made of a rubber-concrete body which is precast in a mold and cured as in the manner of Portland cement concrete. After drying in an oven or other means, a laminated layer 21 comprising a plastic resin composition 3 reinforced with fibrous strands 7, e.g., fiber glass strands in the form of mat or woven roving, or fabric, or strands of unidirectional fiber glass disposed in oriented directional placement are bounded and integrated to the rubber-concrete body. The stranded material is placed best to resist impact loads coming to the trafiic guard rail structure from wheel impacts of moving vehicles or from body impacts of moving -vehicles. The reinforcing layer 21 is an enclosing layer on all sides (or on a lesser number of sides as required) and acts as does a jacket in containing the rubber-concrete core 10 but with a restraint that may be greater than the compression strength of the rubber-concrete core 1-0. The core 10 has by reason of the rubber content of the concrete mixture 21 susbtanti-al tensile strength and compression strength. The core 10 can be bent slightly and will recover to its original state, which property stands in good stead in the resistance of dynamic loading. The rubberconcrete is a resilient material, not brittle, but has a toughbinders. The high compression strength of ness due to the specially compounded and related mix design of the materials used to make core 10. 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 or the rubbery material of the invention that is used has a substantially different cyclic capacity than the Portland cement and aggregates common to the cement concrete field. If 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, e.g., stone, clay particles, fire 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. The rubbery polymeric resin composition 3 covering and encasing and bonding the fibers, e.g., fiber glass, has portions of the composition 3 extend into the pores and interstices connected therewith of the rubber-concrete core 10. The integrating extension provide a very strong yet very resilient bounce characteristic co-acting with rubber-concrete core 10.
The resulting construction provided is tough, strong, and highly resistant to impacts. The polymeric resin composition binder, or other binder, and bonding material 3 has as a component thereof a color selected, e.g., white, black, or red, or yellow, etc. (or is multi-colored). This color is a pigment comprised of a mineral stable to the use intended (or a chemical color) and is particularly color stable and wear resistant and chemically inert to the binders of both polymeric resin and Portland cement. Epoxy, epoxy-polyamine, epoxy-polysulfide rubber resins, polyurethanes, and polyester resins discretely used as is known in the art provide excellent the composite materials of the rubber-concrete core 10 and the skin-stressed laminated layer 21 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 yarns, or it represents fine metallic wires, or synthetic fibers, or inorganic or organic fibers, etc., of which fiber glass for the present is preferred. Polypropylene fibers and monofilaments, or polyethylene filaments especially having carbon black filler, or nylon, and/ or other thermoplastic filaments and sheets and films may be used in discrete combinations with fiber 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-fiber integument 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 fiber 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 plasticresin composition fiber glass reinforcing layerintegument in resilient bond.
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 or decorative features. By selecting an upper range on Mohs scale of hardness of filler like commercially made A1 0 aluminum oxide, the surface characteristics of the rubberconcrete core 10 is hard and in the bonded and integrated surface layer composition 21 is made most durable. The hardness of the filler in this case, about 8 on Mohs scale, 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 is able to stand differences of temperature and of expansion and of expansion and contraction internally as Well as loadings externally expressed, and these fillers and resins provide such structure. The mineralogical characteristics and crystal habit of the filler materials I use provide many new and interesting features of color, luminescence and are especially useful in this invention. Some of the minerals embedded in the surface layer 21, 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, guard rail, etc. The addition of pearl-like particles from and of sea shells makes a good reflective surface construction for embeddment in the plastic resin composition of layer 21. C-orundum particles are especially used against light or white backgrounds of plastic resin composition having such a white or colored filler, etc. White titanium pigment or yellow ochre pigment have the advantage of being very hard, approaching 8.0 on Mohs scale of hardness for minerals. By polishing off the outermost resin surface film and in some instances polishing off the aggregate particles, I make extremely beautiful surface constructions having the desired utility as safety elements such as guard rails.
Crushed abolone shells provide iridescence of the shell particles when used in a clear resin surface of the outer layer 21. Glass beads 83 embedded in the clear resin surface of the outer layer 21 makes reflective surfaces which reflect on-coming headlights of cars and trucks and are used in an approved safety manner.
The plastic resin composition embedded and embedding the fiber glass strands or other type of fibrous reinforcement of the invention is advantageously a filled polymeric resin composition, e.g., an epoxy resin having a discrete curing agent, e.g., Bakelite brand epoxy resins ERL-2774, ERL3794 and ERL2795 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 ERL2795, the least viscous of the three resins, possess good handling characteristics and performs well in room temperature applications. ERL2774, which is more viscous, gives superior strength and electrical properties at elevated temperatures. Both resins exhibit good solvent resistance with ERL-2774 being slightly superior. The third resin, ERL3794, is quite similar in most respects to ERL-27 74, but has a slightly higher viscosity. It is recommended for applications requiring extreme solvent resistance.
The epoxy assay, gram per gram-mole epoxy for ERL- 2795 is 179-194; for ERL-2774 is -200; for ERL- 3794 is 174-186, with the viscosity, c.p.s. 77 deg. F. being 500-700; l1,000-14,000; and 12,000l9,000 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 coetficient of expansion of the cured resin system. Fibrous fillers such as chopped glass fiber or steel wool may be added to increase strengths and impact resistance. Epoxy resins offer outstanding resist ance, e.g., chemical resistance, particularly caustic resistance, excellent strength and toughness.
One method of making an embodiment of the invention is to take a specular faced mold, or other type of mold as then being used and fill said mold with a layer of pigmented polymeric resin composition, e.g., 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, which when exposed by initial wear of the surface of the prestressed traflic control marker and bumper-guard rail, have the said particles illuminated by the glint feature provided by them in their faceted particle faces. These particles are distinct crystal like particles, e.g., passing a /8 of an inch mesh screen and being retained on a 30 mesh Tyler screen. Particle size is important because fines below 30 or 60 mesh do not provide enough faceted surfaces to reflect the light of oncoming cars.
Into this layer of filled polymeric resin composition is placed a plurality of fiber glass reinforcing fibers in the form of a multidirectional mat on top of which are placed a plurality of unidirectional fiber glass fibers and strands located in directions of resistance to the impact loads expected to be resisted by the traflic control marker and bumper-guard rail in its use. The strands may be glass fiber Woven roving of 60 end 150s fiber and may have the warp rovings the same diameter as the woof rovings, or 30 endroving 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 oncoming 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 is the resin comprising the integrant 78 and is provided in a predetermined amount directed to the 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.
A particularly highly visible embodiment comprises an embodiment of crystal reflectors of about 1" in diameter bonded to the structure so-that a pattern of brilliant reflectors is seen in the surface of the traflic guard rail structure. The reflectors may project a small amount to increase their visibliness or they may be flush with the top surface. If the traflic control marker and guard rail construction is used at a location requiring further warning to drivers, the reflecting medium may be lighted from within the element which in this case would be a hollow column or conduit providing both supporting structural characteristics as well as providing means through which to carry electric wiring connected to such a light source.
Another means of providing an active illumination source of light within the traflic control marker and resin composition, much like guard rail construction is to provide electric lamps of discrete size and wattage in a socketed electrical device known in the art and place this plurality of lights below a transparent layer of fiber glass reinforced polymeric a lens, which in use, would but would also magnify it. of the traflic control marker and guard rail construction device can be made integral with the layer 21 or it can be made as a removable portion of layer 21 fastened to the marker by fastening means.
Another means of providing active illumination to the traflic control marker and guard rail construction is to allow the reinforcements to project above the surface of the traflic control marker and guard rail construction a discrete distance and have as their surface light reflecting media, as crystals, or glass beads, which reinforcements could be removable when worn down and replaced by new ones.
If Plexiglas is used for this reinforcement, or at least the top portion of it being of Plexiglas and which is connected to a source of light Within the embodiment the light may be piped through the Plexiglas.
FIGURE 1 is an isometric view of a traflic control bumper-guard-rail device of the invention attached to a roadway and adapted to protect vehicles from damage by impact and keep them from going oif of a roadway. The rubber-concrete core body 5 of the bumper-guardrail is made in convenient lengths as mass produced machine made products as in concrete block machines or as massed produced product made in molds of any convenient size and length. Advantageously such a bumperguard-rail device is made of a rubber-concrete having very rubbery elastic properties in order for the bumperguard-rail to provide a resilient cushioning impact when struck by the bumper of a car or truck or other vehicle. The surface layer 27 is reinforced with fiber glass reinforcing in the form of mat of multidirectional fibers, or of mat of woven unidirectional fibers, or of unidirectional fibers oriented and disposed in predetermined design directions in accord with an engineering plan to provide the type and kind of resistive mechanism desired.
The contour of the curved surface of FIGURE 1 is such that it offers only a small area of contact for any bumper of the average car or truck so as to limit marking of the car or truck by impact. The surface layer 27 is reinforced in its layer and is also reinforced by the projecting finger-like protrusions of resin composition 78 which are integrated into the pores and interstices of the core body 5.
Advantageously, fiber glass reinforcing cables as disclosed in my copending application Ser. No. 340,642, filed Jan. 16, 1953, a portion of which is now US. Patent No. 2,951,006 are shown at 15a on one side of the core and are prestressed tendons bonded into the recesses provided for them in the manufacture of core 5. The reinforcing tendons 151) are also shown on the opposite side of the prestressed traflic control marker and bumperguar-d-rail and are also prestressed tendons.
Shown in the inside of the core body 5 are prestressed tendons 19 of similar construction as tendons 15. These reinforcing cables are unidirectional strands of fiber glass embedded in a polymeric resin composition having at least 3% elongation and preferably a little more so that if a tendon is worked to its ultimate strength just under its breaking strength, the resin embeddment and easing can elongate with the fiber glass and not crack or fail. Rubber-like features are thus provided in both the cable and the resin composition protecting the fiber glass from adverse influences as for example alkali in a concrete miX. Alternatively, the said tendons may be made of steel having adjustable end anchorage means.
To work such a construction as in FIGURE 1 to an advantage to provide the very resilient bumper-guard-rail construction of the invention, the tendons 19 are stressed in tension and anchored by bonded anchorage in and to not only transmit the light The lens portion of the face the body of core 5, which tensile stress is related in amount to the tensile stress induced similarly and anchored similarly in tendons 15. I have found that by keeping the interior tendon 19 in a state of prestressed preload substantially greater than the prestressed preload in tendons 15a and 15b, the bumper-guard-rail device when hit with a sharp impact blow from a car bumper bends away from the impact and induces additional loading in tendon 19 which already is in a greater state of load than tendons 15a and 15b but as this occurs by reason of the tendon 19 being in the center of the core this permits the bumper-guard-rail device to bend outward and in so doing increase the load in tension on cable 15b. Such an impact reaction then cycles through the bumper-guardrail and on the rebound loads cable 1511 which impact reaction is snugged up by cable 19 because it has the greater load of prestressed preload. The result is that impact loading is changed rapidly in cycle and is dissipated as heat by the alternative force reactions in the cables; and also as in the rubber-concrete surrounding the cables. At a distance away from the point of impact on the bumper-guard-rail device, the transmitted forces tend to move the inner tendons toward the roadway so that a snake-like oscillating movement occurs in the cable tendons 15a and 15b at this point. Energy is again released in the act of the tendons giving way to the impact of the force. While the oscillations are occurring tendon 19 by reason of its greater internal prestressed preload, tends to restrain the oscillatory movements and again energy is released so that the composite force reaction is one in which substantial dissipation of kinetic energy expressed as dynamic loading is obtained. Alternatively, the said tendons may be made of prestressing type steel having adjustable end anchorage means which may be adjusted for tensile loading during their use.
Cooperatively in a designed manner, the material of the core 5 being of a very resilient rubber-concrete, cushions the forces also so that they impact against a rubbery acting material which resiliently resists while yielding to the impact. A person in a car or truck striking the bumper-guard-rail of this invention does not meet up with an irresistable force or material, but rather is cushioned and cradled force wise by the resilient rubber-concrete bumper-guard-rail which dissipates the impact loads. The long fiber glass cables in their own right have at least 3% elongation before ultimate load is reached and the resilient bonding of elastomeric rubbery resin of the elements 78 provide another phase changing medium for the loads to travel through.
The bumper-guard-rail device can be and is made in straight line configurations as well as in curved line configurations. Concrete posts 11 or other equivalent supporting means are made as prestressed posts if desired and have substantial strength over and above ordinary wood, steel or ordinary concrete steel reinforced posts.
FIGURE 2 shows an isometric View of a traffic control marker and bumper-guard-rail device serving both as a means to warn drivers by an illuminated visible body and a means to absorb shock of impact should they hit the bumper. A channel 31 is precast into the rubber-concrete core 5 and may be made as a continuous channel or may be made as a spaced channel of appropriate length to receive a lighting fixture, each to be spaced at a predetermined interval in the bumper-guard-rail body. The lighting fixture may be of any known type either illuminated by the on-coming headlights of a car or preferably, a lighting fixture having a neon light 36, or other electric light source providing positive illumination.
FIGURE 3 illustrates an isometric view of a trafiic control device and guard rail structure having an integral heating means 39 which melts snow and ice from the guard rail structure and insures that the guard rail is always visible when freezing rain or snow obscures the guard rail structure. The heating device comprises a resistance wire circuit providing heat from an electric 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 traffic control guard rail structure is similar as in FIGURE 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. It is known that marked resistance is shown by a reaction product of ethylene dichloride and calcium polysulfide, and by Thiokol, a polymethylene polysulfide. 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 e.g., 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 polysulfide 20 Pale crepe rubber 1 Zinc oxide 2 Carbon black 5 This material is cured and comminuted 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 sulfide (Na S.9H O) 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 Na S although a certain amount of Na S is doubtlessly formed. If larger amounts of sulfur are used in this example, still gretaer proportions of Na S 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 refluxing 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 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 -140 C. As comminuted particles of plastic materials after wash- Portland cement 1O Silica sand- A mesh to fines 27 Aluminum silicate325 mesh 5 Fire expanded shale-%" mesh 18 Rubber aggregate particles 40 The silica sand and the fire expanded shale can be increased to about 35 parts of silica sand and the fire expanded 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 material being used. Also the degree of rubbery characteristics is controllable by the relationship of the rubber aggregate particles to the bal ance 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 volcanized or of being adhesively bonded by compatible rubber resins.
Another means of providing a rubber concentrate or rubber content to a rubber-concrete mixture advantageously, is by providing granules or particles of fire expanded shale or clay passing a /8" screen and retained on a 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. If 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 of the aggregate before it is usedtomake concrete.
Comminuted particles of used rubber, e.g., 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 rubbereconcrete core 5 or core 10 of the invention, it is important to consider the amount of pores and interstices in the core material so it has a porous 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-mix 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 pumic 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 invention. The term Portland cement includes cement made by the Portland Cement Association and includes special cements that are resistant to temperature 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 Interior of the United States.
among several of an unsaturated tion adapted to an embodiment provides one example polyester resin composiof the invention:
Parts by weight Rigid type unsaturated polyester resin 3178 Flexible type unsaturated polyester resin 908 Benzoyl perovide-l00% assay 40 Milled fiber glass Titanium dioxide pigment 25 Aluminum silicate filler-ASP 400 100 Faceted crystal silicabalanced mix of 30%60 mesh; 30%30 mesh; 20%16 mesh; 20%No. 4
mesh 2724 Glass beads 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.
When the formulation is ready, clean, wax and coat with mold release the molds of the shape required, and cover the specular faces of the mold with about /8 inch thick layer of the above formulation and vibrate the mold to settle the silica filler and glass beads toward the specular face of the mold to make them visible in the face of the product. On this layer place a layer of fiber glass mat reinforcement e.g., 6010- woven roving, or e.g., 2 oz. multi-directional fiberglass mat, or e.g., a surfacing veil of fine spun glass fiber and a 1.5 oz. fiber glass mat, and if more strength is desired in the reinforcement of the layer, use multiple layers of the above as desired. Wet the fiber-glass thoroughly by having the formulation liquids penetrate and permeate the fiberglass mats and provide a surplus thereover in the quantity of formulation desired for integrant penetrated and permeated into the core body 5 or 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 vacuum chamber or device and pull a vacuum in sufiicient 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 or device, next place the mold and its contents on a heated platen press and press to consolidate the materials and cure at a predetermined temperature for a predetermined time, which, e.g., may be in the instant embodiment, 220-230" F. for seven minutes at 15 .s.i.
li ach unsaturated polyester composition has its own curing cycle and this fact must be noted in manufacture. On completion of the cure, strip the product from the mold and store to cool, preferably at a slow rate of coolmg.
As a convenience during manufacture after vacuum impregnation is had, place a piece of cellophane or polyethylene film on the bottom of the product, which is in reverse position during the press cure so that a smooth surface is had.
Example III A trafiic control guard rail structure is precast with a series of grooves traversing the surfaces of the traffic control marker and guard rail structure core so that directionally applied reinforcements are provided to resist impact from any angle of impact. The trafiic control guard rail structure surface is covered with epoxy resinrubber 21 composition and the grooves are filled with unidirectional strands of fiberglass preimpregnated with epoxy resin composition as an embedded construction in the covering epoxy-rubber resin 21 composition. The traffic control guard rail structure thus prepared for reinforcing is then put into a vacuum chamber and the body of the traffic control guard rail structure filled by vacuum with the epoxy-rubber resin 21 composition. The trafiic control guard rail structure is then covered with a surface mat reinforcing embedded in a polymeric resin composition having a fine silica filler, e.g., 250 mesh and a corundum filler e.g., 60 mesh Tyler screen to 16 mesh Tyler screen corundum having distinct faceted crystal structure. The corundum can be White or any other discrete selected color having a distinct faceted crystal structure.
Advantageously, the partially cured epoxy resin composition on the surface of the trafiic control guard rail structure of the invention, may have glass beads, or other high light reflecting media, 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 is available for reflecting light from headlights of oncoming cars and trucks. As the instant traffic control guard rail structure is weathered or dulled by impacts, such glass beads can be re-applied in epoxy resin composition which bonds readily to the traffic control guard rail structure.
Example IV The embodiment of FIGURE 3 is precast of rubberconcrete and with grooves and holes as shown in the instant figure. When cured and ready for lamination proceed as in above disclosures after inserting cables 15 and 19 which are made and used as in disclosures and claims of my Ser. No. 340,642, filed Jan. 16, 1953, a portion of which is now U.S. Patent No. 2,951,006. In my copending applications of record in this case several means of prestressing prestressed preloads into the cable construction in FIGURE 3 appears and said means can be used herein. In place of Portland cement being used as the binder for rubber-concrete, such a rubber-concrete can be made by using plastic resins, rubbers and/or elastomeric sustances as disclosed and claimed in my U.S. patents as issued of record.
It is recognized that while the instant invention has been described and is claimed for the beneficial improvements provided to traffic control guard rail structures, the principles of this invention are not limited to only these embodiments of invention, but on the contrary, are recognized as being beneficial improvements in other structural load bearing constructions wherein rubber-concrete plastic-resin composition reinforced structures have a place of use.
Although some of the embodiments and examples set forth herein are substantially identical with those given in companion cases covering related but distinct inventions, it will be readily understood by those versed in the art of patent law and practice that this is because these practical articles and methods embody inventions, each or some of which can be used with or without the others, i.e., some of the inventions thus together may be considered optional or can be replaced by alternatives.
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 in vention is to be given its broadest possible interpretation within the terms of the following claims.
What is claimed is:
1. A prestressed traffic control marker and bumperguard rail comprising at least one core-body having face surf-aces, said core-body being formed of resilient rubber-concrete porous material and having a surface layer on at least one face thereof providing resilient support against impacts, said surface layer comprising a bonded and impregnated polymeric resin composition having a filler and pigment of light reflective material disposed therein, said core-body being substantially filled in its porous structure by an integrant comprising a rubbery resinous composition, a system of internal reinforcement comprising at least one prestressed reinforcing cable located substantially in the central portion of said corebody and extending longitudinally thereof, at least one prestressed reinforcing cable located just below the face of said surface of said core-body and extending longitudinally thereof on the side adjacent the roadway to which it is adapted to be placed, and a substantially identical prestressed reinforcing cable located just below the face of said surface of said core-body and extending longitudinally thereof on the side away from the roadway to which it is adapted to be placed, said centrally placed cable being prestressed by an amount greater than that of either of the outer placed prestressed cables.
2. A prestressed traffic control marker and bumperguard rail as recited in claim 1, said core-body being provided with warning safety lighting means therein capable of illuminating at least a portion of the area adjacent to where the core-body is to be mounted.
3. A prestressed traflic control bumper-guard-rail as recited in claim 1, in which said prestressed cables comprise unidirectional fiber glass strands embedded in resilient polymeric resin composition and said cables being capable of at least three percent elongation and having substantially complete recovery memory under loading and unloading, said cables being resiliently bonded to the structure of said rubber-concrete core-body by impregnating and permeated projections of said bonding resin in said porous structure of said rubber-concrete core-body.
References Cited by the Examiner UNITED STATES PATENTS HARRISON R. MOSELEY, Primary Examiner. D. L. TAYLOR, Assistant Examiner.