US 3687021 A
Methods of and means for permitting and providing vertical liquid drainage in a support or surfacing construction; a structure permitting vertical liquid drainage therethrough; substructure operative to provide vertical liquid drainage therethrough operative to receive outdoor coverings thereon; combination constructions which are vertically draining including: (1) vertically draining structures with coverings thereover; (2) same of different degrees of coarseness; (3) same associated with playing surfaces, optionally with resilient mats therebetween; (4) same having liquid impervious coverings therebeneath; (5) vertically draining surfacing constructions coupled with draining means therebelow; methods of making up and laying surfacings of rock and plastic which, when set, permit vertical liquid drainage therethrough; combinations of surfacings which permit vertical liquid drainage throughout the entire area thereof with (a) various footings, (b) impervious liquid repelling means thereunder, (c) coverings therefor, (d) carpetings thereover, (e) liquid draining means thereunder, and (f) playing surfaces optionally with mats thereover.
Description (OCR text may contain errors)
[451 Aug. 29, 1972  VERTICALLY DRAINING FLAT STRUCTURES Billy R. Hensley, 829 E. 17th Tern, Ottawa, Kans. 66067 22 Filed: Feb. 24, 1970 21 Appl.No.: 13,273
 US. CL; ..94/9, 94/7  Int. Cl. ..EOlc 7/18  Field of Search ..94/3, 4, 7, 23, 9, 10
 References Cited UNITED STATES PATENTS 1,484,514 2/ 1924 Lloyd ..94/3 1,906,494 5/1933 Steward ..94/7 2,044,498 6/1936 Pearce ..94/4 2,185,341 l/194O Irvine .....94/23 X 2,21 1,649 8/ 1940 Drury ..94/4 2,515,847 7/1950 Winkler ..94/7 X 3,022,712 2/1962 Cousino ..94/7 3,112,681 12/1963 Gessler ..94/7 3,418,897 12/ 1968 l-Iumalainen ..94/7 2,225,458 12/1940 Murphy ..94/7
FOREIGN PATENTS OR APPLICATIONS 517,831 10/1955 Canada ..94/4
Primary Examiner.lacob L. Nackenoff Attorney-Thomas M. Scofield ABSTRACT Methods of and means for permitting and providing vertical liquid drainage in a support or surfacing construction; a structure permitting vertical liquid drainage therethrough; substructure operative to provide vertical liquid drainage therethrough operative to receive outdoor coverings thereon; combination constructions which are vertically draining including: (1) vertically draining structures with coverings thereover; (2) same of difierent degrees of coarseness; (3) same associated with playing surfaces, optionally with resilient mats therebetween; (4) same having liquid impervious coverings therebeneath; (5) vertically draining surfacing constructions coupled with draining means therebelow; methods of making up and laying surfacings of rock and plastic which, when set, permit vertical liquid drainage therethroughycombinations of surfacings which permit vertical liquid drainage throughout the entire area thereof with (a) various footings, (b) impervious liquid repelling means thereunder, (c) coverings therefor, (d) carpetings thereover, (e) liquid draining means thereunder, and (f) playing surfaces optionally with mats thereover.
12 Claims, 5 Drawing Figures VERTICALLY DRAINING FLAT STRUCTURES PRIOR ART Taylor US. Pat. No. 1,171,560, Feb. 15, 1916 Grass Growing Apparatus and Method of Making Same shows and teaches that grass may be grown in soil which is laidover a bed of rocks so that moisture drainage can be effected.
Eilers US. Pat. No. 1,690,059 Hard Court for Ten nis and the Like, Oct. 30, 1928, discloses a tennis court made of a bottom layer of granulated, blast-furnace slags coated with either a layer of finer and sifted slags of the same kind or a mixture of finer, sifted slags of the same kind and powdered bricks (brick dust); This porous construction purportedly permits water to pass therethrough.
Steward US. Pat. No. 1,906,494 Playing Surfaces, issued May 2, 1933 discloses an artificial'felt play surface underlaid by a discontinuous layer of asphalt adhesive or other non-water soluble adhesive, the latter secured to a base of porous concrete, with a final lower layer of broken stone. The porosity of these various layers is disclosed as permitting water drainage whereby to prevent rotting of the play surface.
OBJECTS OF THE INVENTION An object of the invention is to provide a flooring, surfacing or flat structure which permits vertical drainage of liquids through such floorings, etc. useful for many applications whereas to' be able, in many cases, replace asphalt, concrete, ceramic or metal and also provide a rigid, strong,'long lived, easily applied, relatively cheap surfacing construction.
Another object of the invention is to provide a light weight, porous structure comprised of rock, a plastic binder and air spaces, these three elements so arranged and so proportioned as to be more useful and economi- I cal than solid cement, asphalt or ceramic structures, due to its combination of porosity and drainage features, while yet retaining and providing sufficient rigidity and strength for the various purposes desired.
Another object of the invention is to provide a flooring, surfacing or field floor structure which permits vertical drainage therethrough of liquids, particularly water, thus being uniquely adapted for such uses as football, baseball and sports fields, patios, parking lots, factory wet processes, shower stalls in homes, any walkway (sidewalks), flooring constructions, airport runways, retainer walls and the like.
Still another object of the invention is to provide a flooring, surfacing material, substructure or subsurface operative to provide throughout the body thereof, vertical drainage for liquids, particularly water, thereby greatly improving and effecting the drying and cleaning of outdoor coverings such as carpets, mats and the like.
Still another object of the invention is to provide a flooring, structure, surfacing, substructure or subsurface which is operative to support and carry various types of outdoor coverings such as mats and carpets, which is competitive in price with concrete and asphalt, yet provides structural advantages, particularly vertical drainage of liquids therethrough, not possessed by either.
Another object of the instant invention is to provide methods of and means for providing and permitting vertical liquid movement and drainage in and through a surfacing structure which is covered by and/or supports an outdoor carpet or mat.
Yet another object of the invention is to provide a vertically draining (of liquids such as water) flooring, surfacing, walkway, runway, roadway or like structure which may be placed directly over the earth or ground, or (alternatively) be underlaid by a footing of varied construction, or yet further (alternatively) may be underlaid by a liquid collecting and draining or liquid impervious film, sheet or surface, same useable by itself without any overlying covering of any sort, 'or yet, (further alternatively) useable in layers of different porosity and internal structure, same optionally covered by a carpet or mat or, yet further, same optionally first covered by a resilient mat and thereafter being covered by a game playing surface, artificial grass mat or yet other types of carpet.
Still another object of the invention is to provide a surfacing construction having a great variety of uses which may be varied by varying the composition or makeup of its constituents to effectively accomplish very many commercially and industrially desirable and useful purposes.
Other and further objects of the invention will appear in the course of the following description thereof.
DRAWINGS In the drawings, which form a part of the instant specification and are to be read in conjunction therewith, a number of various embodiments of the invention are shown in the various FIGS.
FIG. 1 is a side-sectional view through an earth formation on which is supported a surfacing construction embodying the instant improvements and other elements including (from top down in the view) a top carpet, a perforated rubber or resilient material mat under said carpet, the surfacing construction itself and a water impervious, plastic sheet or septum, all of these elements comprising a cooperating unit for purposes to be described.
FIG. 2 is a view like that of FIG. 1, but showing a flooring or surfacing construction, ground mounted, involving the use of a top carpet or mat directly supported by the subject liquid permeable substructure.
FIG. 3 is a view like the previous figures, but showing the subject surfacing construction of rock and binder, vertically permeable by liquids, the latter supported on a footing of sand and gravel or sand and rock, the footing overlying the surface of the ground or earth.
FIG. 4 is a side-sectional view, somewhat schematic, of a typical flooring which may be used in wet industrial or manufacturing processes, the flooring comprising an upper layer of rock and binder employing therein rock of lesser size whereby to have lesser permeability therethrough yet a smoother surface, the lower portion of the flooring, integrally bound to the upper portion thereof, comprising rock and binder with the rock particles of greater size than those in the upper portion, the entire flooring received in or mounted on a liquid impermeable pan having draining means in the bottom thereof.
FIG. 5 shows a surfacing construction combining the features of FIGS. 2 and 3 wherein an overlying mat covers the subject vertically draining rock and binder construction, the latter then received on a footing of sand and gravel, the footing overlying or carried on the surface of the ground or earth.
Referring first to FIG. 1, at 10 is seen the earth or groundlevel. This may be a level or slightly angled earth surface. If it were a football field, for example, if one were to look through a cross-section of the ground across the width of the field while standing centered between the goal posts, the ground would be highest in the center of the field and sloped gently toward each sideline. The purpose of the latter is so that there will be outward drainage from the center of the football field. The section here shown is far too small in area to show any such details of curvature. In the case of a baseball field the field would be essentially flat save for themound (pitchers mound) but with the infield built up from the baselines thereon and both the outfield and the infield probably slightly built up from thesurrounding ground. In the case of a patio or limited area athletic field for, say, tennis, basketball, or the like, the field would probably be essentially flat. The instant flooring or surfacing construction and compositions, however, can be so laid and-so configured as to match any desired ground grading and thus such is not critical to the invention.
Overlying the ground level at 11 in FIG. 1 is a plastic septum or sheet which is liquid and water impervious. This sheet may be of any desired thickness or may be of multiple or ply thicknesses, as desired, but a simple vinyl sheeting of 0.0 (inches) thickness would suffice in most cases. When such a sheeting 11 is used, the ground should be graded and smoothed level and be absent of rocks and sharp protrusions such as pieces of metal, roots, masonry fragments, etc. Likewise, the overlying structure on top of the septum or sheet must be relatively smooth on the underside thereof and integral so as not to cut or perforate the sheet. The object of sheet 11 is to collect and catch liquids or water thereover and, due to angling of the surface on which it lies, pass it laterally. Thus it is contemplated that there be some grading or angling of the ground surface 10 so that liquid which collects over sheet 11 will'move to one side or another or centrally or peripherally of a certain zone for collection or removal purposes.
Alternatively, the top surface may be level and flat, while the bottom follows a grade for drainage purposes. As previously noted, this does not preclude a parallel structure following the grade for drainage purposes. Both are satisfactory and some level surfaces such as tennis courts would drain quickly down and then laterally. Thus, also, with a football field graded (viewed in end section) from the center downwardly on each side, one could employ a dead level top surface on top with the under surface following the grade, thus draining quickly.
Positioned above and lying on sheet 11 is a thickness of the instant surfacing, substructure, or vertically permeable flooring construction comprising a plurality of rock or gravel particles 13 joined together, one to the other, in an integral mass bybinder 14. The entire surfacing layer or level is generally designated 12. This is a thickness of material typically for non-critical uses as walks and patios ranging from 2 to 8 inches (for critical uses such as sports and air fields) thick, relatively smooth on the top and bottom surfaces thereof and may follow the contour of the ground lying thereunder or be level (per above). That is, the upper surface can be level and lower surfaces of layer 12 run substantially parallel to the grade and the layer 12 can be of uniform or other form thickness, depending on the extent of the grade and the requirements of the final surface.
Positioned above layer 12 is a regularly perforated rubber or other resilient surface mat 15. Mat 15 overlies and bears against the upper surface of layer 12 in the same manner that the lower surface thereof bears against sheeting 1 l. Perforations 15a in mat or sheet 15 are for the ready passage of liquid or water therethrough. A typical thickness of rubber mat for an athletic field would be three-eighths to five-eighths inches and the openings therethroughtypically, but not necessarily, would be one-eighth to one-fourth inches in diameter and spaced 5 per square inch. The upper level or layer of the combined construction of FIG. 1 comprises a carpet or mat 16 which may or may not have artificial grass blades (not seen) incorporated or provided on one side thereof. Such latter described mats are available commercially and in use in several locations. A typical thickness of mat in the construction shown would be one-fourth inch and the mat typically would be composed of nylon, acrylic, polypropylene or other plastic fibers.
The construction shown is optimum for use in a high school, college or professional football field. The use of septum 1 1 is for particularly damp or high precipitation climates where it is not felt that water which would pass through the carpet 16, mat l5 and structure layer 12 would be adequately dispersed or absorbed by the soil before freezing. In such cases, there would be drainage and collection facilities at the sides of the field. In a drier climate with less rainfall, or with sufficiently porous soil, as well as warm climate, the septum might not be used. However, it must also be kept in mind that, in any case of an artificial covering or carpet, it is desirable to periodically scrub or hose off accumulations of dirt, dust, particles of the mat, particles of the players, their uniforms, dust droppings from vehicles or animals that might pass thereover, and the like. Thus, there generally will be a considerable quantity of water (independent of rainfall) which will fall on the top of mat 16 and pass through to the ground and must be taken into consideration.
Referring to FIG. 2, therein is shown a simplified construction comprising the ground or earth level 17 (this could be an asphalt or concrete surface, but is preferably dirt). The subject surfacing layer is positioned directly thereabove and generally designated 18 made up of rocks 19 and binder 20. A top mat layer 21 patio. Any water (rain or cleaning hosings, etc.) which falls on carpet 21 passes therethrough into the earth level therebelow. In the event that a fine (or finer than FIG. 2) top surface under the carpet is desired for a highly smooth carpet support, the flooring construction in FIG. 4 is employed (without the bottom drain of FIG. 4).
Referring to FIG. 3, therein is shown a construction readily used as and adapted for such uses as a roadway, a walkway, an airport runway or a sidewalk. As a base there is seen ground level at 22, leveled and smoothed not necessarily to the degree required with respect to the structures of FIGS. 1 and 2. Above ground level there is provided a footing (generally designated 23) typically made up of gravel, stones or rock of various sizes indicated at 24 and sand 25. Positioned on top of the footing is a continuous layer, sheet or body of the subject vertically liquid permeable surfacing (generally designated 26) and made up of rock particles 27 bound together integrally by binder 28 at the interfaces between individual rocks.
In FIG. 4 there is illustrated a typical flooring for a wet industrial process or a flooring useable in an industrial or home shower stall. In either of such cases, for example, it is necessary to have a relatively smooth and fine structure flooring surface which is also strong, yet which may be readily cleaned of particles and the like from above (laterally across the top thereof) yet which is still vertically permeable by liquids, including water. Thus, there is first provided an upper or top layer (generally designated 29) of relatively fine (small diameter) stones or gravel 30 held together by binder 31 at the interstices of the rocks. The flat upper surface or top 32 of this upper layer of flooring is quite level or at least even. It may be angled inwardly centrally whereby liquid will tend to run toward the center of the flooring or room or it may be angled to one side or the other, depending on the purposes of the room or floor. Positioned immediately below said upper layer or thickness 29 and in continuous engagement there is a (generally designated 30) portion or thickness of the subject surfacing or substructure made up of relatively large rocks or gravel 31 held together by binder 32 at the interstices thereof. The binder of the lowermost portion of layer 29 bonds to the uppermost rocks of layer 30 and vice versa for an integral structure. The vertical peripheral limiting wall 33 of the floor, shower stall or the like may comprise a cylindrical sheet, band or strip of metal. The base floor proper, at 34, comprises a metal sheet continuously connected (liquid tight) at its outer edge to wall 33 and inwardly extending to the drain portion 35. Thus, water or other liquid which falls on top of surface 32 permeates downwardly through level 29 and thereafter into level 30 thence down to the sheet 34. The water collected on sheet 34 then moves centrally due to dishing of the portion 34 or otherwise) to drain out pipe or conduit 35, only one wall of which is seen.
In FIG. 5, there is seen a construction combining the features of FIGS. 2 and 3. That is, there is seen a ground level 36 which is preferably leveled or shaped as desired on the upper earth surface 37 thereof. However, the finishing is not necessarily as smooth or fine as desirable in FIGS. 1 or 2. Above ground level 37 there is provided a footing layer generally designated 38 having gravel or rocks 39 therein and sand 40. Positioned above the footing layer is a layer or level generally designated 41 of rocks 42 held together by binder 43 to form an integral yet vertically liquid permeable construction. On top of the essentially level or slightly graded upper surface 44 of level 41 is positioned a mat or carpet 45. (Particular envisioned uses of this set of elements may be patios, walk surfaces, the same as FIG. 2. This form is useful usually where the application is on clay or impervious hardpan (no drain).
MATERIALS Referring to the rock content of the subject structure, there will never be an absolutely uniform consistency.
The plastic composition will typically range from 3 to 7 percent by weight of the final structure.
Generally speaking, as the rock size increases, the binder percentage required lowers. In consideration of the loads for a specific use or specific uses for a given size of rock in the structure, the higher load requirements may require more plastic (and a smaller size rock). For example, with inch rock, the structure would be quite crumbly at 3 percent by weight plastic and would be losing porosity at 7 percent by weight plastic. With respect to 2 inches rocks, the 3 percent by weight plastic would have a lesser strength, while there would be runs of plastic visible when over 5 percent or 6 percent plastic is employed, thus showing a waste of plastic at a given strength.
In case one desires a floor or surface structure which has an upper, use surface of a finer texture, one may use (as in FIG. 4) a mixture of finer or smaller average diameter or size rocks for the upper portion thereof with the required (generally relatively greater) quantity of binder therefor and a coarser or larger average diameter stone below with its (generally relatively less) required binder percentage. This combination will give a cheaper structure (less binder used in the lower portion) while achieving the desired goal of the finer surface. This may be made an integral construction by first making up and laying the lower structure, then making up and laying on top thereof the upper structure (mixing and adding binder to the stones in the larger lower section and then pouring or laying it, and then mixing and laying or pouring the top layer thereover while the lower is set or unset, but clean and in good condition).
APPLICATIONS In the case of the Monsanto mat (used for football playing fields), on top is the grass carrying mat structure and below that there is a solid rubber mat. This is laid onto the surface of a layer of cement or asphalt. In my case, I employ a top layer of grass carrying mat, then therebelow a perforated rubber mat for resilience and drainage purposes, then finally therebelow my binder-rock vertically draining structure. A footing as in FIG. 3 or the water impervious sheet of FIG. 1 (or both) may also be employed. (The comparison here is for the same use, namely, surfacing for an athletic field for all-weather purposes. The Monsanto company product only has lateral drainage with all its problems, while my construction can provide vertical drainage to ground through all the structure.)
Another application of the instant construction is seen in the use of the vertically draining structure for airport runways. In this use, the ability to transfer quantities of water from rain, hosings, and the like to the soil underneath (usually via footings as in FIG. 3) will minimize landing and take off problems in adverse weather conditions, particularly avoiding hydroplaning. A finer top layer as at 29 in FIG. 4 may be employed if desired. In laying or applying the structure, it should be understood that several successive thicknesses of uniform rock size and binder content (or only one) may be laid and if the second or third layers are put down on a green lower layer (binder unset) those layers will bond integrally. The same is true of successive layers of finer rock relative to themselves or other type layers.
EXAMPLES 1-7, INCLUSIVE The following are specific examples of the invention:
1. 3M Company (St. Paul, Minnesota) epoxy adhesive 4 percent by weight, the balance being rock of greatest dimension averaging three-eighths to onehalf inch. (Sample in hand 2 inches thick, cylindrical, 3% inches in diameter, needled indoor-outdoor carpet one-fourth inch thick adhered to one side by being applied to the green uncured structure.)
2. 3M Company epoxy adhesive 3.7 percent by weight with the smallest rock not passing a 3/64 inches opening, the pebbles running up to ya inch in greatest dimension. (Sample in hand 2 inches thick, cylindrical, 3% inches in diameter, needled indoor-outdoor carpet one-fourth inch thick adhered to one side same as (l 3. 3M Company epoxy adhesive 5.5 percent by weight. A %inches square screen sieved out all particles that could pass therethrough with the largest pebbles of diameter or largest dimension onehalf inch. (Sample same character as described re (1) and (2) re dimensions and carpet.)
4. 4.75 percent by weight of Cook Paint & Varnish Co. of Kansas City, Missour Polycor polyester (styrene monomer) adhesive with the rocks sieved by a A; X Va inches screen. This rock content is labelled shot and rock dust at the quarry with the largest pebbles being about inch in the largest diameter. (Sample in hand: rock-binder lower layer 1% inches thick, 3% inches in diameter (cylindrical); on top surface of lower layer is adhered V2 inch thick rubber (6O durometer) mat with 47 (one-fourth inches) holes, latter topped by adhering A inch thick Ozite indoor-outdoor carpet.)
5. 4.03 percent by weight Cooks polystyrene (Polycor) adhesive, employing shot and rock dust of Example (4) as rock content. (Sample in hand same character as (4)).
6. 2.50 percent by weight of Cooks polystyrene (Polycor) adhesive, employing shot and rock dust of the character of the last two examples. (Sample in hand same character as (4) and (5)).
With respect to Samples 4-6, inclusive, the rubber layer was stuck to the rock and the carpet to the rubber layer by coating the rubber layer (not closing the holes) and'applying the rubber layer to the rock and the carpet to the rubber. A cement such as B. F. Goodrich Plyabond or Armstrong Cork Company's outdoor carpet cement was utilizable in each case.
7. This is 3% percent plastic by weight in the body (Cooks Polycor adhesive). with the body rock utilizing approximately r inch size gravel from the quarry rock pile labeled one-half inch in which may be observed some obviously larger rocks. The surface was dust and shot the same as (6). There is too much plastic in this surface layer for the desired porosity.
These one-half inch? quarry designated rocks are provided unwashed and unsifted from the quarry. A surface layer (one-fourth to three-eighths inch thick) or thickness of unwashed and unsifted rock dust and shot, barely pervious with the samebinder percent present. (Samples 4-7, inclusive were painted on rockbinder layer (sides and bottom) with a white pigment.)
The body proper of Sample (7) is 3% inches thick and 3% inches in diameter (cylindrical) with the surface thickness given.
APPLICATIONS up of water pressure therebehind. These would be vertically oriented or at the desired earth face angle or grade and following the desired earth face configuration which they contain. (Thickness: normally 4 to 6 inches thick, vertical to flat, leaning into the bank to be held.)
The structure could be used as desired to handle any sort of flowing problem depending on the flow volume desired, the character and content of the liquid, the hydraulic pressure, load requirements, etc.
The plastic employed may be colored or carry a coloring material or filler therewithin to provide a desired color for an athletic field, air field, patio, driveway, walkway, or the like.
Another application (see FIG. 4) is in the use of a floor where a wet industrial process is employed. It is often desirable to employ a wet process'(industrial) on a flat floor where no slope is required to spaced drains or a central drain. This construction applied has the advantage of drainage at any point on the floor and additionally, not be slick. An adhesive must be employed not reactive with the process liquids. The process liquid must be clean and compatible with the binder plastic. It will fail under solvents that desolve or react with the plastic binder used. If one compares the use of concrete or the structure of concrete or the combination of concrete mixed with rock with my construction:
First, to get a comparable structure with concrete, that is, impervious to flow therethrough, one would have to employ at least 10 percent by weight adhesive, for example epoxy (discuss the transition ranges with respect to various sized rocks for seal off). Secondly, I
use plastic adhesive instead of the chemicals which making up the binding reactants in concrete. Thirdly, my-structure comprises the plastic plus the rock rather than the concrete structure which results from the chemical process forming it (the formed chemical compounds after the reaction and setting) plus rock. Finally, my ingredients are always ready and do not require the preparation that concrete does. I merely l dump in theplastic, (2) dump in the rocks, (3) mix (or vice versa with respect to order of addition of plastic and rocks) and then lay the structure on the earth or wherever, in one or several layers with'successive layers same or different.
UNDERSTRUCTURES In the drawings, there are shown the following understructures:
I. The rock construction directly against grade; (FIG. 2)
2. The rock construction over a fill; (FIGS. 3 and 3. The rock construction over a plastic septum or sheet; (FIG. 1) g 4. The rock construction over an impervious surface, sheet or container base of metal or the like (FIG. 4) which serves, like the plastic septum 'mentioned, to gather the water to take it to a drain or other.
The sheet of FIG. 1 may be over earth level or over a fill or yet over a surface as in FIG. 4. In the latter case it may be a teflon or like coating on the surface. The carpet of FIGS. 2 and 5 may be over the rock structure as shown or over a finer layer as in FIG. 4. Likewise, the rubber or composition mat of FIG. 1 may also be used over a finer surface as in FIG. 4.
UPPER SURFACES The upper surfaces shown in the drawings comprise:
I. An artificial grass simulating carpet over the rock structure or any other single carpet, such as a patio outdoor carpet directly over the rock structure; (FIGS. 2 and 5 2. The rock structure coveredby a perforated rubber or compositionmat, the latter then covered by a grass carrying carpet or other desired outdoor carpet; (FIG. 1
3. The upper portion of a rock structure of a defined rock particle size and binder content (uniform dimensions throughout) acting as the upper layer and surface (FIG. 3);
4. A rock-binder construction of desired thickness, porosity, surface character, rock size and binder content being the cap or upper portion of a total rock structure of different character below. (FIG. 4)
MATERIALS The purpose of the plastic septum, sheet or film 11 in FIG. 1 is to avoid the soil beneath the rock structure filling with water. If freezing conditions are possible in the locality, such freezing of the soil could operate to heave the soil and thus create uneven support or perhaps even fracturing of the rock structure, depending on the type and distribution of the loads to be encountered on top thereof. The plastic septum collects the water and permits it to be drained out to the side, but the presence of the rock-binder structure thereabove gives a considerable water holding content not found in a carpet alone or a carpet and supporting resilient mat in combination.
Also there will be some lateral drainage in the rockbinder structure if there is'some sloping thereof. A football field, for example, is preferably slightly humped along the center line thereof, draining toward both sides.
One picks the desired rock size by defining that which, with the quantity of binder necessary to hold the structure together under the loads to be encountered which will also drain all quantities of liquid from the top surface in a desired time.
Thus, enough flow must be provided to handle the contingent conditions. In a rain situation, this usually would be relatively low. In industry, in a floor drainage situation under wet conditions, it could be very high.
Under spray cleaning or hosing conditions for a playing field it could be high, but such cleanings could be so timed as to permit slower drainage and drying of the soil.
' EXAMPLES With reference to atypical and specific example of a combination structure which would be analogous to that seen in FIG. 1, but omitting the bottom plastic septum or sheet, the following may be employed. On the top would be a thickness of Ozite (Polypropalene fiber non-woven neddled or woven carpet or other suitable needled or woven plastic fiber carpets one-fourth inch thick being normal) carpet. Below this would be positioned a inch soft rubber pad or padding having is to A inch holes therethrough, five holes to the square inch or about this size opening. This padding would be secured to the lower surface of the Ozite carpet by adhesive. Below the rubber padding layer would be the rock and plastic substructure. This would be secured to the bottom surface of the rubber padding by a suitable I adhesive. An optimum thickness of the rock and plastic substructure for football fields would be 4 to 8 inches. The rock size would be one-eighth to three-fourths inches average size, average greatest dimension -or average diameter. The plastic would comprise 5.5 percent by weight of the total rock-and-plastic substructure and may be the Cooks polystyrene defined supra. One purpose of the one-half inch thick soft, perforated rubber padding is to even out the topmost surface. It also adds cushion or resilience and passes water. Outside carpets known to the art, such as Astro Turf have had artificial grass carrying carpets integrally padded with some sort of solid material.
Still another example (No. 9) is made up from Riverside Quarry, Riverside, Missouri, material defined by the Riverside Quarry as rock dust and shot. I sifted and washed this material. Thereafter, I removed all of the dust that would pass through a 3/64 inch opening and all that could be removed by passing water over that which remained. I then allowed the larger rock sizes to remain, as they came from this rock dust, etc. pile. I estimate the largest materials will pass through a inch opening. The bonding material com prised Cooks polystyrene Polycor to a content of 3.7 percent of the total weight. The bonding material was applied by first wetting the rock with hardener, then applying the plastic, both with a rotating, tumbling TESTING Compressive strength tests were carried out with respect to nine specimens by the Associated Laboratories of Kansas City, Missouri, 2920 Oak Street. The table given below tabulates the results of these tests. Three Samples 13A, 14 andl employed Va inch rock. As defined here, /8 inch rock passed through a 3/ 16 inch square mesh and was retained on a 7 8 inch square mesh. Three samples 11, 12 and 13 utilized /zinch rock. As defined here, a in'ch rock passed through a inch square mesh and was retained on a a inch square mesh. Then three Samples 8, 9 and utilized inch rock." Three-eights inch rock, as defined here, passed through a A inch square mesh and was retained on a 3/16 inch square mesh. The rock was crushed limestone. Cooks Paint and Varnish Co. Polycor polyester resin was employed.
With respect tothe three samples utilizing inch rock," a first sample utilized 2 percent (by total weight of sample) plastic and had a compressive strength of 567. psi Sample No. 10. A second sample of this set contained 3% percent plastic and showed a compressive strength of 979 psi Sample 9. The third example of this group of specimens contained 4% percent plastic and displayed a compressive strength of 1,151 psi Sample 8 1n the second group of samples utilizing V2 inch rock, a first sample incorporated 1% percent plastic and had a compressive strength of 442 lbs. Sample 13. A second sample of this group contained 3.30 percent plastic and demonstrated a compressive strength of 846 lbs. Sample 12. The third sample of the group contained slightly less than 5 percent plastic (over 4% percent) and demonstrated a compressive strength of 1,018 lbs. Sample 11.
In the third group of samples, utilizing Va inch rock," the first sample contained 3.15 percent plastic and displayed a compressive strength of 764 lbs. Sample 13A. The second sample of this group contained 4 7/8 percent plastic, displaying a compressive strength of 1,404 psi Sample 14. The final member of this group, containing 6% percent plastic displayed the highest compressive strength of its group (and of all samples) with 1,684 psi-Sample 15.
All samples passed water therethrough at a rate estimated at greater than any rainfall would be, from a (household) faucet.
CONCLUSIONS Conclusions may be drawn from this data as follows:
1. Curves may be drawn for each group and the curves superimposed with respect to one another for comparison with compressive strength (psi) as the ordinate and percentage plastic as the abscissa;
2. Generally speaking, the larger the average rock size, the weaker the structure for a given plastic percentage;
3. For a given rock size, the more plastic present, the
stronger the structure.
TABLE] COMPRESSIVE STRENGTH AREA 1 1.642 Square lnches Sample Height. Load Compressive No. 1n Inches Lbs. Strength PS1 8 5% 13,400 1 151 9 5 11,400 979 I0 5 6,600 567 ll 5 11,850 1018 12 4 9,850, 846 13 4 5,150 442 13A 5 8,900 764 14 5 16,350 1404 15 5 19,600 I 1684 ADHESIVE 0 BINDER With respect to the plastic adhesive employed in the rock-binder construction as the hinder, the binder or plastic adhesive utilized in all samples or specimens listed above after number 3, that is, Nos. 4-15, inclusive was the Polycor polyester resin of Cook Paint and Varnish Co., general offices, Kansas City, Missouri, specifically, Polycor 939-X-300. This is'characterize d as an air inhibited, accelerated, mediumthixotropic resin formulated for hand lay-up or spray assembly applications." It requires the addition of methyl ethyl ketone peroxide catalyst to. cure. Data on this specific resin is given in-a 3 page paper entitled 939-X-30 0, dated Sept. 21, 1966 and giving data under the following headings: Description, Liquid Resin Properties, Gel Time Data At VariousTemperatures In Minutes, Typical Gel And Cure Schedule Using Various Catalysts (seven catalysts are presented), Physical Properties, Storage and Shipping. This paper, published by Cook, supersedes 939-X-300 dated Sept. 3, 1964. This paper is in my hands and a copy will be supplied if the Patent Office requires it. Additional data with respect to these resins are found in the brochure or catalogue for Polycor Polyester Resins and Gelcoats" subtitled General Method of Application," also by Cook Paint and Varnish Co., the Polyester Division, date of publication: May, 1969. There are some 30 subtitles in this document. A copy of this document is in my hands and data therefrom as required by the Patent Office will be supplied. From Page 1, column 1 of this publication,
the character of the polyester resins may be summarized:
Polyesters are polymers that are made up from a number of small units. These units orv building blocks are commonly made from raw materials known as maleic anhydride, phthalic anhydride and a glycol such as ethylene glycol. These building blocks are joined together by applying controlled heat or cooking.
By varying the amounts and types of building blocks we can produce different types of polyesters rigid, flexible, fire retardant, chemical resistant) It is understood that suitable polyester resins and, indeed, various other different chemical composition binder may be utilizable in the instant invention. The purpose of these specific examples listed above and the publications noted is to indicate that specific compounds, useable for he various other purposes noted have been identified, used, tested and evaluated for the purposes of the instant invention. These examples are not intended to be limiting and are illustrative only.
From the foregoing, it will be seen that this structure is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of terpretedas illustrative and not in a limiting sense.
Having thus described my invention, 1 claim: 1. An integral composite construction formed of rocks sized within a limited range of overall dimension and bonded one to the other by a synthetic plastic binder,
the quantity of said plastic binder present in said construction sufficient to bind all of the rocks together into an integral, structurally strong (load-supporting) mass,
yet limited with respect to the quantity of said rock present,
whereby sufficient gaps and interstices are present substantially uniformly distributed among and between all of said rocks and the synthetic plastic connecting them together that liquids will drain both laterally and vertically through a thickness of said composite construction from one side to another,
said rocks of relatively uniform overall size with respect to one another,
(the difference in dimension of average size of rocks in the construction not exceeding. 100 percent),
the average rock greatest dimension varying fromone-eighth inch to 2 inches and the plastic content varying from 3-7 percent, inclusive, of the total weight of the rock-plastic composite construction,
the quantity of plastic present substantially inversely proportional to the rock average size.
The plastic employed of a viscosity such as to provide a thin coating on each particle substantially waterproofing said particles,
and offering sufficient adhesion so said particles are bound together without substantial decrease in the void space between the particles.
2. A construction as in claim 1 which comprises an earth covering flat layer varying from 1 to 8 inches in thickness.
3. A construction as in claim 2 including a mat or carpet adhered by adhesive to the upper surface of said construction.
4. A construction as in claim 2 including a footing of sand and gravel below said construction between it and the earth surface.
5. A construction as in claim 2 including a plastic sheet or septum between the lower surface of said construction and the earths surface.
6. A construction as in claim 2 including a thickness of resilient water pervious material adhesively adhered to the upper surface of said construction, said layer regularly perforated for water penetration and a carpet or mat layer adhered adhesively to the upper surface of said resilient layer. f
7. A construction as in claim 1' wherein the rock comprises V2 inch rock (defined as passed through a 74 inch square mesh and retain on a 1% inch square mesh) and the plastic is present in the range 1% to 4% percent by weight of the total weight of the rock-plastic construction.
8. A construction as in claim 1 wherein there are two layers, both liquid permeable, one layer having rocks of relatively uniform overall size of a relatively lesser dimension, the other layer having rocks of relatively. uniform size therein and of a relatively greater dimension, said layers bonded integrally to one another.
9. A construction as in claim 2 wherein there are two layers, both liquid permeable, one layer having rocks of relatively uniform overall size of a relatively lesser dimension, theother layer having rocks of relatively uniform size therein and of a relatively greater dimension, said layers bonded integrally to one another.
10. A process of constructing an integral'composite construction formed of rocks sized within a limited range of overall dimension and bonded one to the other by a synthetic plastic binder comprising mixing such quantity of said plastic binder with a quantity of rocks of said limited range of overall dimension together,
said plastic binder present in sufficient quantity to bind all of the rocks together into an integral, structurally'strong (load supporting) mass,
yet so limited with respect to the quantity of said rocks present, whereby, when said construction is laid into position, sufficient gaps and interstices are present sufficiently uniformly distributed among and between said rocks and the plastic connecting them together that liquids will drain through a thickness of said composite structure from one side to another, both laterally and vertically,
said rocks of relatively uniform overall size with respect to one another,
(the difference in dimension of average size of rocks in the construction not exceeding the average rock greatest dimension varying from one-eighth to 2 inches and the plastic content varying from 3-7 percent, inclusive, of the total weight of the rock-plastic composite construction, the quantity of plastic present substantially inversely proportional to the rock average size,
the plastic employed of a viscosity such as to provide a thin coating on each particle substantially waterproofing said particles, and offering sufficient adhesion so said particles are bound together without substantial decrease in the void space between the particles,
and applying a thickness of said structure to the earth surface before said plastic sets.
11. A process as in claim 10 including adding a second layer of said construction in contact with said.
the rocks in said layers of relatively uniform overall size in each layer but of differing dimension