US3396641A - Fabrication of slag surfaces and structures - Google Patents

Description

g- 3 1968 G. WELTY ET AL 3,396,641

FABRICATION 0F SLAG SURFACES AND STRUCTURES Filed Dec.

AC1 w m .n m 1 u @QL W5 QJ N w v 0M [S United States Patent 3,396,641 FABRICATION 0F SLAG SURFACES AND STRUCTURES Lloyd G. Welty, 132 S. Lasky Drive, Beverly Hills, Calif. 90212, and Simon J. Sluter, 5523 Rimpau Blvd., Los Angeles, Calif. 90043, assignors of one-half each to Welty and Sluter Filed Dec. 16, 1964, Ser. No. 418,840 3 Claims. (Cl. 9422) Our present invention relates, in general, to the fabrication of composite trafiic bearing surfaces and other structures employed for a variety of utilitarian purposes, and having properties conducive to safety in service. More particularly, our invention relates to the fabrication of such structures from slag.

It is already known to fabricate composite surfaces and structures for somewhat similar purposes from other materials. For example, US. Patent 2,925,831 utilizes a fragmented cinderlike material of volcanic origin for such fabrication.

It has now been found that slag, hitherto thought to be merely a worthless waste product in a metal smelting process, can be used in the fabrication of surfaces and structures with resultant unique features and improvements over existing compositions as will be described in detail hereinafter.

Subsequent to reclamation the slag is preferably reduced to the appropriate size for use by conventional grinding, rolling and screening methods.

Spectrographic analyses of typical slag and scoria specimen are as follows:

It will be appreciated that the indicated materials will be combined with oxygen and other components to form the various chemical compounds of the minerals.

As employed herein, slag is defined as the dross which is obtained as a product of smelting a metal from an ore containing silicates and generally with a lower specific gravity than the metallic substances extracted. For example, slag may be produced in a smelting operation in which fluxing agents such as limestone and fluorite are intermixed with a siliceous ore, e.g., of iron which mixture is then fused as in a blast furnace. The slag as dross forms a fluid layer overlying matter smelted metal wherefrom it is poured off and cooled. The cooled material is then fragmented and sized as described above.

As may be noted slag differs quite markedly from volcanic scoria in chemical composition. The slag granules also differ in being of the order of twice the density of the scoria and has a compressive strength and abrasion resistance of upwards of twice to three times that of scoria. Slag and scoria possess individually distinctive surface characteristics and structure together with other differences noted elsewhere herein provide compositions of correspondingly different characteristics which are particularly advantageous under different conditions of use. Moreover, admixtures of the present slag fabricating materials and of the aforesaid scoria aggregates yield products of intermediate physical properties. Also, scoria may be employed in one or more layers of the composite structures while the slag may be used in others, especially in the surface layers to enhance reflectivity, abrasion resistance, physical strength, etc.

More particularly, slag and slag-scoria mixture may be employed very advantageously in the fabrication of heavy duty traffic bearing surfaces. In such fabrication the slag is employed in conjunction with certain adhesive bonding agents to promote the bonding of a substrate surface to a variety of coating layers, the slag particles serving to provide a mechanical interlock between the substrate, the bonding material and the coatings, while the bonding agent is of a nature which reacts with the coating material to practically fuse therewith. The concept is applicable not only in the provision of traffic surfaces but for the application of successive constituent layers over metal, wood, brick and other surfaces of similar nature so as to provide a variety of other composite mechanical structures. Moreover, the fragmented slag particles produce a concave mirror effect because they have cup-shaped exterior surface depressions facing in all directions giving a uniformly reflective surface. In addition to providing a remarkable degree of bonding, the composite or lamellar structure produced as described hereinafter, possesses other highly advantageous characteristics such as skid resistance, minimal ablation to fire, very high compression strength, shock resistance, and others.

Accordingly, it is an object of our invention to employ slag to promote the bonding of various substrate surfaces to covering layers in the fabrication of composite and lamellar structures.

Another object is the provision of resinous bonding means to effect the successful bonding of a layer of material such as an asphaltic composition to a substrate of concrete or the like.

Another object of our invention is to employ slag in conjunction with resinous "bonding agents to promote the bonding of an asphaltic road surface covering to a substrate surface.

Still another object of our invention is to employ slag as a binding or component layer over plane and curved surfaces in the fabrication of traffic bearing surfaces or mechanical structures.

A further object of the invention is to employ slag in the fabrication of non skid traffic bearing surfaces incorporating a self-sharpening effect with surface usage.

A still further object is to produce a slag traffic bearing surface that has a built in light reflective feature.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description and the accompanying drawing of the preferred form of the invention. It is to be understood, however, that variations in the form of the disclosed description and drawings may be adapted within the scope of the invention as set forth in the claims.

Referring to said drawing:

FIGURE 1 is a cross sectional view of a composite surface structure as applied to a hard substrate surface in accordance with the invention.

FIGURE 2 is a cross sectional view of a composite surface structure as applied to a soft unset substrate surface.

FIGURE 3 is an enlarged view of a portion of the structure which demonstrates the manner in which the light reflective feature of the invention is incorporated therein.

FIGURE 4 is a cross sectional view of portions of a tubular composite structure constructed in the process of the invention.

In brief, the fabrication processes of the invention generally involve an initial operation wherein a layer of slag particles or fragments is bonded to a relatively smooth substrate surface by means of certain adhesive agents. In this manner the substrate surface is covered by a large number of relatively closely-spaced outwardly projecting slag fragments or particles tightly bonded thereto. Under certain conditions application of a separate bonding agent may be dispensed with since certain substrates may be made to serve a similar purpose in early stages of manufacture. The substrate surface prepared in this manner is now in an ideal condition for the application of additional layers such as of various paving or structural materials to complete the composite surfaces and structures of the invention. Such additional layers may be of an adhesive character, however, it is not necessary that such be the case since a firm mechanical bond will result between the slag and various dough-like materials which do not ordinarily otherwise yield a sufiiciently strong bond.

In the fabrication of trafiic bearing surfaces in accordance with the invention, the substrate on which the superimposed layers are applied will ordinarily be relatively rigid and unyielding such as set or hardened concrete as illustrated in FIGURE 1. Old or new concrete, asphaltic paving, wood, rock, brick, metal and other similar substances are adaptable for the application of a composite surfacing in accordance with the invention. A clean and roughened surface 11 is invariably necessary to ensure the best result and, accordingly, loose material, oil and the like are removed by wire brushing, sweeping, sandblasting and other appropriate operations such as acid cleansing.

A layer 12 of fluid adhesive bonding agent is then applied as by spraying on the surface. The selection of an appropriate bonding agent will depend on the nature of the substrate surface and the ambient conditions under which the surface is to be employed. In some instances a solution of adhesive material which solidifies by evaporation of the solvent, may be employed. Likewise, it is possible to employ bonding agents which can be applied in a molten condition and which solidify on cooling; however, it is generally preferred to employ a resinous bonding agent of the catalyzed setting type. Solvent solutions as asphaltic, coal tar or other resinous materials exemplify the first mentioned type of adhesive bonding agents. Aqueous emulsions and dispersions of adhesive bonding agents of a similar character may be employed likewise. Molten asphalts, coal tar, resins and synthetic resins exemplify the second type of bonding adhesive.

The preferred setting type of resin or chemically reactive class of adhesive with which the maximum advantages of therslag particles are obtained constitute the catalyzed epoxy, phenolic, polystyrene, acrylic esters, resorcinol-formaldehyde, polyurethanes, polyester and silicone resins which set at ordinary room temperatures and at accelerated rates with increased temperatures. Epon resins (828 etc.) supplied by Shell Chemical Company, Araldite resins (502,6010, 6020, etc.) supplied by Ciba, Plastics Division, C-8, Devron and other epoxy resins are generally prepared by the condensation of epichlorohydrin and 'Bisphenol A (4,4-isopropylidenediphenol) to various molecular weight polymers yielding viscosities of fluid, to molasses-like, to thermoplastic solids. Catalysis by agents and mixtures thereof including organic bases, acid anhydrides, compounds containing active hydrogen, certain resins, and the like, is employed in the multitudinous commercially-available formulations. Plasticizers such as Thiokol fluid and others can be employed therein. Phenolformaldehyde liquids can be cured with organic bases, resorcinol-formaldehydes cure at room temperature with additional formaldehyde and urea-melamine-formaldehyde cures at room temperature or coplymerizes with others of the phenolic and epoxies. True polymerizing adhesive bonding agents derived of styrene, allylic compounds, acrylic and methacrylic esters are cured with benzoyl peroxide or other organic peroxide and especially in the presence of a redox catalyst system. Polyurethanes and hybrids with poly-urea cure in the presence of water and acid.

When the phenolic and especially, the epoxy type of adhesive bonding are contacted with bituminous or asphaltic surfaces or compositions in the course of constructing the composite structures of the invention, a chemical reaction has been observed to occur which markedly modifies the appearance of the asphalt or bitumen in the contact region. Microscopic examination reveals that there is no sharply defined interface between the resin and asphalt or bituminous phases of the bond region but that a coalescence occurs therebetween so that the intermediate region is a highly modified resinasphalt or bitumen composition which varies to either side of the intermediate region so as to attain the composition of the adjacent phase. Although the nature of the reaction is not fully understood, it is believed that a type of crosslinking reaction occurs between the indicated types of resins and reactive sites of the compounds in the asphaltic or bituminous materials. Active oxygen, hydroxyl, amine and other nitrogen substituents, and unsaturated side-chains present in such materials would be susceptible of such reaction. As a result the physical properties of the asphalt are modified, e.g., the bond region is less thermoplastic than the adjacent asphalt, it is harder and more resistant to shock, tensile properties are improved, etc. It will therefore be apparent that the bond obtained with these materials is not merely the adhesion usually obtained by surface effects but is literally a fusion to provide a far superior inter-mingled bonding region. The intermingled bonding region produced by the composition of the above may be produced in volume thickness as a homogenous mass as well as by creating a bonding contact layer. In other words, this composition of asphaltic tar epoxy resin and slag aggregate may be a surface coating, or be of more extensive columetric proportions.

While the bonding agent layer 12 is still in a fluid state a layer of the slag particles 13, free of fines and uniform in size, is applied with rolling if necessary to assure that the lower surfaces thereof are thoroughly wet by the agent or are embedded partially therein. With surfaces such as walks, floors, decks, etc. to which only a relatively thin covering is to be applied, mesh sizes of A /8 inch or larger may be employed. In the event that the surface is to be used by heavy vehicular trafiic, or requires frictional characteristics materials of A1, /2 inch or larger mesh sizes are employed. Ordinarily, the bonding agent is then allowed to set, heat being applied if necessary thereby conditioning the substrate surface for the bonding of additional layers of material thereon. In this sense the bonding agent-slag layer will be understood to constitute the bonding layer of the completed composite structure.

The covering or surfacing layer which may under certain conditions be considered a filler layer is applied over the layer 12, either in a dough-like plastic or semiplastic state and rolled into the interstices between the bonded aggregate fragments and into firm contact with resin covered substrate and aggregate surfaces or the ad ditional layers may be built by applying dressings of the cinder-like aggregate and then spraying a binder constituent thereover. Finally, a dusting layer of aggregate particles of appropriate size may be applied or rolled, if desired, into the surface, particularly, where the maximum in non skid properties is desired. For maximum adhesion of the dough-like layer 14, an adhesive bonding layer 15 is sprayed over the projecting fragments 13 before layer 14 is applied.

For street and roadway surfacing or paving, e.g., reconditioning of highway surface, cold mix, hot paint mix and other types of asphaltic or coal tar binding paving materials are employed as the layer 14. Alternatively, slag of a range of mesh sizes (dust to ca. 42 inch) may be applied and an asphaltic emulsion or solution sprayed thereover, as a binder, similar to seal coat paving methods to provide layer 14.

With new concrete base roadways, the slag may be partially imbedded in the soft concrete surface to provide the bonding layer as illustrated in FIGURE 2, thereby omiting the initial adhesive bonding layer of FIGURE 1. In this case the completed surface structure will include a concrete substrate 20 having a clean surface 21, slag fragments 22 embedded therein and a covering layer 23 of dough-like filler composition bonded with adhesive layer 24 applied as by spraying on to the upper substrate surface 21 and exposed surfaces of the slag fragments 22. In the event that filler 23 is sufficiently adhesive, bonding layer 24 may be omitted.

An enlarged view of the region of a single slag particle 22 partially exposed out of the covering layer 23 is shown in FIGURE 3 of the drawing to illustrate the manner in which the light reflective feature is built in and also the manner in which the trafl'ic bearing surface is skid resistant.

As shown in FIGURE 3, the slag particle has many concave mirror effect surfaces 25 facing all directions. This gives a uniform reflective surface for light proportional to the particle size and the number of particles per square foot as each particle summit is surrounded by a valley. In addition, the particle summits create a backward reflection towards the source rather than an angle reflection forward as will be noted by the majority of incident light rays 26 being reflected substantially rearwardly from the surfaces 25 toward the light source. The cup-shaped exterior surfaces accomplish this either in daylight or at night time whether wet or dry.

The slag particles also maintain their very high and uniform coefiicient of frictional resistance with wear. When an exposed particle eventually breaks down and disintegrates an underlying particle thereby becomes exposed and also creates a non-skid surface. Thus, our invention utilizes a uniformly frictional surface with a given number of frictional particles to the square foot. For example, one square foot of slag or scoria surfacing composition registers between 15,000 to 20,000 surface particles of /s" screen size per square foot. This characteristic insures a consistently even vehicular braking action simultaneously on all wheels of each vehicle whether the surface is wet or dry.

In the event that a higher grade or structurally strong surface layer 14 is required, e.g., in interiors, on decking, Walkways, rigid panels and the like, it is preferred to employ a binder of the resinous adhesive agent types described above. The amount of binder may be varied from the minimum required for cohesion and adhesion of the aggregate dressing to the bonding layer to the amount necessary to provide an essentially non porous surface.

Surfacings and coverings applied in the manner described are remarkably adherent to the substrate surface. The bond is resistant to thermal shock and load bearing stresses as well as to weathering. With the amount of binder limited to increase the porosity, surface drainage is excellent while, with increased amounts of hinder the layer as a whole is water tight and therefore the substrate is protected to the maximum extent.

The principles described above are also employed in the fabrication of structural forms such as tubing, panels or for the application of insulation and corrosion resistant coverings to various surfaces. For example, very diflicult problems are encountered in providing corrosion resistant coverings for pipelines. A bonding layer of slag applied to the substrate pipeline surface as described above facilitates the application of the conventional asphaltic and coal tar protective coverings. The bonding layer is particularly efficacious when a heat plasticized covering layer is extruded to cover pipeline sections prepared with the bonding layer as described above.

Tubing and panel sections as illustrated in FIGURE 4, are constructed by providing a base 30 from metal,

fiber, sheet material, e.g., fiber glass matting or fibrous cloth impregnated with a fluid laminating resin of the epoxy, phenolaldehyde, polyester and similar types or with a thermoplastic binder as employed in conventional practice. While the binder or laminating resin is in a fluid state the slag fragments 31 are applied as described above. Ordinarily, the binder is then allowed to cold set or the laminating resin is at least partially cured with the application of heat if necessary to provide a stable layer of bonded aggregate fragments.

Subsequently, a plastic composition 32 of the aggregate in admixture with an adhesive binder is applied smoothly over the bonding layer. In some instances curing at this stage will produce a satisfactory structure, however, for maximum strength an outer laminated coverling layer 33, similar to the substrate base is applied. Tubing or panel sections made in this manner are rigid, weather resistant, durable, light weight, economical and possess many other desirable properties.

Further details of the invention will be apparent in the following examples:

EXAMPLE I A substrate surface of hot asphalt plant mix applied over a standard crushed rock road base is covered with /2" screened slag aggregate of the character described above. While the substrate is still in a heated condition the aggregate layer is rolled with suflicient pressure to imbed the aggregate particles about halfway into the soft asphalt layer. The upwardly projecting portions of the particles now present a large surface area including numerous spicules and concavities while the lower portions are tightly imbedded in and bonded to the asphalt substrate.

A fluid setting adhesive agent is then applied as by spraying over the aggregate studded substrate surface. A suitable adhesive bonding agent A is compounded, illustratively, a follows (various of the other adhesives indicated may be used equivalently):

(1) Fluid resin (Applied Plastics Co., #210) parts 4-6 (2) Hardener (Applied Plastics Co., #180) part 1 (3) Plasticizer (General Mills Corp., #125) percent volume 3-10 A representative fluid epoxy resin type bonding agent B is prepared as follows:

Parts 1) Epon 828 (Shell Chemical Co.) (2) Triethenediamine or equivalent base 8 (3) Phenyl glycidyl ether (optional) 5 (4) Fluid Thiokol (plasticizer) 10 Application of the adhesive agent yields a prepared bonding surface on the aggregate studded substrate.

A dough-like aggregate preparation is applied over the prepared surface as by trowelling or with mechanical spreading equipment. The aggregate dough usually is prepared from slag aggregate of smaller screen sizes than those comprising the bonding layer. An aggregate mixture C may comprise, e.g., 1 part of A mix screened slag aggregate particles and 2 to 16 parts of A2" screened particle sizes. The aggregate mixture C is admixed with 5 to 20% by volume of either mixture A or B determined by the amount of interstitial porosity which is desired in the finished surface. The larger proportion of resin is suflicient to provide an essentially smooth surface, if desired.

The aggregate dough is applied in a thickness which is at least sufiicient to cover the bonding aggregate par ticles (about A") and generally in depths to at most of about 1" in thickness. A maximum initial frictional surfacing is obtained by dusting the surface with aggregate fines. Dependent on the temperature the surfacing hardens in times ranging from less than an hour at elevated temperatures to several hours at usual ambient temperatures.

The surfacing obtained in this manner is harder, more wear resistant and skid resistant than ordinary asphalt surfacings. The asphalt is protected by the insulative qualities of the aggregate from buckling, rolling and cracking under variant temperatures and pressures and repairs may be quickly made by replacing damaged surface in the same manner as the surfacing i usually applied to the aggregate bonding layer. The surface may be the naturally-attractive color of the aggregate or pigmented aggregate may be employed in providing the final surfacing. Moreover, the surfacing is inseparable from the substrate surface and is very resistant to damage from thermal shock.

Old asphalt or bituminous surfaces are treated in a similar fashion; however, the old surface is cleaned and degreased or abraded and a coating of mixture A or B is sprayed thereon prior to application of the bonding aggregate particles. A very firm bond is thereby obtained to the old surface.

EXAMPLE II A substrate of freshly poured and rough finished concrete is an ideal base for applying a surfacing in accordance with the invention. Before the concrete has set, a layer of the slag aggregate of V2 to 1" screen size is spread evenly over the surface and rolled to imbed the particles about halfway into the concrete. After the concrete has set a light coating of mixture A or B of Example I is sprayed over the appregate bonding layer and dough-like mixture C of Example I is spread or trowelled smoothly into place. Curing takes place as in Example I.

The surfacing applied over concrete as described herein has essentially the same advantageous properties as those described in Example I. However, certain additional advantages are also obtained, viz., the surfacing eliminates the dusting of the concrete substrate and if applied within a few days after the concrete is poured, curing of the concrete is promoted through moisture retention. Old concrete traffic hearing or wall surfaces are resurfaced in the same manner; however, in this case the surface is sandblasted or abraded mechanically or acid is applied thereto to remove dirt and oxidized materials whereby an adequate aggregate bond is obtained.

EXAMPLE III Rigid or semi-rigid plastic materials such as panels or other forms of foamed polyethylene, isocyanate, polystyrene or phenolic resins are also suitable substrates. Very often such foamed materials are employed in walls, roofing and floors of refrigeration, or marine installations wherein heavy loads or traffic is encountered.

To apply the aggregate bonding layer an adhesive coating of hot tar or of an asphaltic adhesive cement is applied to the load bearing surface. While the adhesive is still soft slag aggregate particles of from A to /2" screen size is imbedded therein and the adhesive is allowed to harden. Finally, the aggregate surfacing is applied as described in Example I.

It will be appreciated that the surfacing is applicable to panels prior to installation or in situ. The surfacing enhances the insulative value, fire resistance and water absorption characteristics of the foamed resin material. If the treated panels are to be employed for visible surfaces, the appearance can be modified by scrolling, texturing or application of pigmented aggregate material. In some cases, where water resistance is not critical, the adhesive tar mixture may be eliminated and the doughlike mixture spread and rolled to effect the bond either with or without the application of bonding adhesive agent such as A or B.

EXAMPLE IV A metal substrate surface is cleaned by degreasing or other appropriate means such as sand blasting or wire brushing. A catalyzed setting adhesive resin of the phenolic, epoxy or silicone type having a heavy molasseslike consistency, e.g., 1000 to 5000 centipoises is applied as a coating to the metal substrate surface. Slag aggregate particles in uniform sizes preferably in the range of A to about /2" mesh size are then applied to the surface as a uniform layer and the resin is caused to set, with moderate heating, if necessary, to provide an aggregate bonding layer.

The final surfacing which is applied thereover will be determined primarily by the application in which the surfacing is employed. Marine decking and trafiic bearing decking such as bridges, etc., are provided by applying a dough-like, resin-aggregate mixture similar to that of Example I and in a similar manner.

Steel and iron pipeline substrate surfaces may be prepared in a similar manner. However, for this and similar applications, lower cost materials have been found to yield satisfactory results. Under conditions in which severe soil stresses are encountered, the aggregate bonding layer is applied as above. Subsequently, a thermoplastic bituminous mixture composed of slag aggregate mixture C and about 20 to 35% of asphalt or coal tar having a melting point of at least 50 C. is heated and extruded around the aggregate studded pipeline sections with conventional machinery. Surfacing layers of /2 to 2 or more inches thickness are applicable in this fashion. The aggregate being firmly bonded to the metal by the resin and the extruded material being firmly bonded to the outwardly projecting aggregate portions results in a very strongly adherent bituminous coating on cooling.

Under some conditions a heated coal tar adhesive may be employed as the adhesive employed to bond the aggregate particles to the pipeline surface. Also an outer layer of coal tar or asphalt pipe enamel with or without the conventional outer wrapping may also be employed, especially, in splicing or repairing.

A coating applied in this manner is not only exceptionally adherent and durable but is also water proof, insulative, and eliminates oxidative, chemical or galvanic corrosion.

EXAMPLE V Load bearing panel-like structures having high stiffness to weight ratios are prepared in the following manner;

A lower sheath substrate comprising either a thin sheet of light metal such as aluminum or one or more layers of glass cloth are coated or saturated with a catalyzed epoxy or phenolic contact laminating resin and is disposed in a horizontal position. A layer of the slag aggregate of a closely graded screen size approximating the thickness of the finished sheet is spread uniformly over the resin coated surface. To facilitate handling the resin is at least partially set by heating and a light coating of the laminating resin is sprayed over the upwardly projecting aggregate particles.

A dough-like filler prepared by mixing van'ous proportions of aggregate fines and screen sizes smaller than the interstices between the bonded aggregate particles (cf. Example I) 10 to 25 parts of the catalyzed laminating resin is then spread to fill the interstices of the bonded aggregate particles.

Finally an upper substrate sheath similar to the lower is coated with a light layer of the resin and pressed into contact with the upper surface of the bonded filler layer and the complete structure is allowed to cure with the application of heat. Curing between platens with a moderate pressure (5 to 50 lbs. per square inch) yields a more compact, rigid and dimensionally accurate structure.

EXAMPLE VI A tubular structure such as a cylindrical section or a tube having a high rigidity to weight ratio is manufactured as follows:

A fiber glass fabric or matting is saturated with a thermosetting epoxy or phenolic adhesive laminating resin and wound around a collapsible mandrel in one or more layers to provide a cylindrical substrate surface. Then an aggregate bonding layer of screened slag aggregate particles, of a uniform to 1 inch mesh size, is partially imbedded in the resin coated substrate and the resin is at least partially cured to provide an aggregate studded cylindrical substrate which can be handled.

The cylindrical substrate is removed from the mandrel and a light coating of the laminating adhesive is sprayed over the aggregate surface. Then a dough-like layer of slag aggregate fines and particle sizes smaller than the bonded aggregate prepared as described above is applied over the aggregate studded cylindrical substrate, preferably by extrusion.

The assembly produced as described above may be cured to produce tubes suitable for many purposes. For example, the ends of the tubes can be tapered and connected by collars to provide pipe-lines, etc.; however, for maximum rigidity at least one external layer of resin saturated glass fiber fabric is wrapped spirally around the assembly and the complete assembly is cured with heating if required.

What is claimed is:

1. In a process for fabricating a composite structural surface, the steps comprising applying to a substrate surface a setting fluid resinous material selected from a group consisting of epoxy, polyester, phenolic, acrylic, polystyrene, polyurethane and silicones, applying and partially embedding a layer of slag particles in said resinous material while it is in its fluid state, said slag particles being particles of a slag material containing metal oxides and produced as a dross of smelting a metal from an ore containing silicates, and applying a filler layer of a composition including an aggregate in admixture with a binder to said surface, whereby the layer of slag particles serves as a bonding layer for the additional layer of composition.

2. A composite structure comprising a substrate base, a layer of resinous material selected from the group con sisting of epoxy, polyester, phenolic, acrylic, polystyrene, polyurethane and silicones bonded to said base, a layer of coarse slag particles partially embedded in said layer of resinous material, said slag aggregate particles being particles of a slag material containing metal oxides and produced as a dross of smelting a metal from an ore containing silicates, and a filler composition of slag aggregate and adhesive binder bonded to said layer of aggregate particles with some of said slag particles protruding from said filler composition to provide concave mirror light reflective characteristics and a high coefiicient of frictional resistance to the surface of said structure.

3. In a process for fabricating a composite structural surface, the steps comprising applying to a substrate surface a setting fluid epoxy resin, applying and partially embedding a layer of slag particles in said epoxy resin while it is in its fluid state, said slag particles being particles of a slag material containing metal oxides and produced as a dross of smelting a metal from an ore containing silicates, and applying a filler layer of a composition including an aggregate in admixture with a binder to said surface, whereby the layer of slag particles serves as a bonding layer for the additional layer of composition.

References Cited UNITED STATES PATENTS 2,158,772 5/1939 Beckwith 156-280 2,306,295 12/1942 Casto 156-278 2,963,045 12/1960 Canevari et al. 138-146 3,008,493 11/1961 Roe 138-146 3,033,088 5/1962 Wittenwyler 94-22 3,161,114 12/1964 Wittenwyler 94-22 2,925,831 2/1960 Welty et al. 94-22 2,934,452 4/1960 Sternberg.

3,038,393 6/1962 Nagin 94-9 JACOB L. NACKENOFF, Primary Examiner.

Claims (1)

1. IN A PROCESS FOR FABRICATING A COMPOSITE STRUCTURAL SURFACE, THE STEPS COMPRISING APPLYING TO A SUBSTRATE SURFACE A SETTING FLUID RESINOUS MATERIAL SELECTED FROM A GROUP CONSISTING OF EPOXY, POLYESTER, PHENOLIC, ACRYLIC POLYSTYRENE, POLYURETHANE AND SILICONES, APPLYING AND PARTIALLY EMBEDDING A LAYER OF SLAG PARTICLES IN SAID RESINOUS MATERIAL WHILE IT IS IN ITS FLUID STATE, SAID SLAG PARTICLES BEING PARTICLES OF A SLAG MATERIAL CONTAINING METAL OXIDES AND PRODUCD AS A DROSS OF SMELTING A METAL FROM AN ORE CONTAINING SILICATES, AND APPLYING A FILLER LAYER OF A COMPOSITION INCLUDING AN AGGREGATE IN ADMIXTURE WITH A BINDER TO SAID SURFACE, WHEREBY THE LAYER OF SLAG PARTICLES SERVES AS A BONDING LAYER FOR THE ADDITIONAL LAYER OF COMPOSITION.

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