Patent Publication Number: US-3874140-A

Title: Structural wall member with sculptured surface and method of making same

Description:
United States Patent 1 [it] 3,874,140  
 Seehusen Apr. 1, 1975 STRUCTURAL WALL MEMBER WITH SCULPTURED SURFACE AND METHOD OF MAKING SAME Primary Examiner-J. Karl Bell Attorney, Agent, or Firm-Townsend and Townsend {57] ABSTRACT A pre-cast structural building wall panel which has at least one sculptured surface defined by a design in the wall panel or by objects such as rock adhered to one side of the panel. The panel is made by forming a sand or gravel bed, inside a form or mold, or placing a form over the bed, shaping the bed by sculpturing the surface of the sand or by placing objects such as rock on the bed and spraying or pouring a first, relatively thin layer of a mortar which includes an adhesive agent. Conventional concrete reinforcing bars are placed in the form after the mortar has set and the form is then filled with concrete. After the concrete has hardened the form is stripped from the panel, the panel is raised from the granular bed, the panel surface facing the bed is cleaned and the panel is then anchored in its upright position at the building site to define a structural building wall.  
 25 Claims, 4 Drawing Figures [75] Inventor: Donald G. Seehusen, Portola Valley,  
 Calif.  
 [73] Assignee: United States Rock Company, Inc., Sunnyvale, Calif.  
 [22] Filed: Mar. 19, 1974 [21] Appl. No.: 452,597  
 [52] US. Cl. 52/315 [51] Int. Cl. B44f 9/04, E040 1/00 [58] Field of Search 52/315, 565; 264/275 [56] References Cited UNITED STATES PATENTS 985,353 2/1911 Landis 52/315 X 1,169,985 2/1916 Mickelson 52/315 X 2,149,784 3/1939 McClatchy et al. 52/315 2,151,420 3/1939 Carve] 52/565 3332017 2/1966 Prusinski ct a1. 52/315 X 3.331.175 7/1967 Terrio 52/315 3502539 3/1970 MacPhail 52/315 FOREIGN PATENTS OR APPLICATIONS 1,405,740 5/1965 France 52/315 STRUCTURAL WALL MEMBER WITH SCULPTURED SURFACE AND METHOD OF MAKING SAME BACKGROUND OF THE INVENTION Continuous attempts are being made to lower construction costs for buildings while enhancing their aesthetic appearance. One common expedient is to preform or pre-cast building wall sections or panels. Where the panels are made of poured concrete they are frequently east on the ground, in their horizontal orientation and then erected and anchored. This greatly simplifies the construction of the molds and permits the economic manufacture of wall sections from reusable molds.  
  The aesthetic appearance of buildings is frequently enhanced by incorporating sculptured walls, or wall sections, facing walls with decorative materials such as rock, combining attractive colors and color combina tion and the like.  
  In the past it was common to first erect the wall, either by building it in situ or by employing pre-cast wall sections and thereafter applying the decorative facing. This took the form of painting the building wall or attaching thereto the desired objects, i.e., decorative panels, rocks, tiles and the like. Difficulties were experienced and prevailed in combining the pre-casting of wall sections with incorporating into such sections the finished surface although the desirability of such a combination is known. For example, US. Pat. No. 3,331,175 discloses to pre-form building wall sections and incorporating therein a decorative facing. However, the method suggested in that patent is cumbersome and expensive. It employs a layer of wax into which decorative building stones or rocks are embedded and over which the structural concrete panel is poured. After the concrete has set the wax must be removed.  
  As a result of prior art failures to economically, practically and aesthetically appealingly combine the incorporation of decorative wall facings and the pre-forming of building wall sections, the old and common practice of finishing the wall sections after they have been erected has been widely adhered to. This is particularly true in instances in which the decorative facing is formed of relatively large rocks or plates such as flag stone.  
 SUMMARY OF THE INVENTION The present invention is generally directed to preformed building wall sections or panels of the abovedescribed type which include, as an integral part thereof,  
 a sculptured, decorative facing or surface. This surface is incorporated in the panel when the panel is formed. Consequently, upon the erection of the panel and its anchoring as part of a building wall results not only in the anchoring of a structural member but simultaneously provides the desired decorative wall facing without the need for a subsequent wall finishing as was common in the past.  
  Thus, the present invention combines the sculpturing of the panel face with the pro-forming of the structural portion of the panel in a simple and economic manner without sacrificing either structural integrity or aesthetic appearance. The present invention is versatile and enables the sculpturing of the panel by sculpturing the panel material per se or by incorporating in the panel exteriorly visible objects such as rock, tiles, decorative plates or the like.  
  In accordance with one aspect of the invention a panel is pre-formed by placing a bed of granules such as sand or, preferably, gravel in an open form or mold. In this connection the term open form denotes a form or mold which generally comprises a frame which has the desired outline. The term placed over (or onto) the sand is intended to mean and means both the placement of a form over a flat sand bed or the formation of such a bed within the form by pouring sand, grave] or similar granular materials into the form while the form is positioned on a horizontal support surface.  
  After the sand bed has been placed in the form, the sand bed surface is sculptured by forming thereon a desired design to the reproduced on the decorative panel surface or by placing onto (or partially into) the bed objects such as rock plates, tiles or the like that are to define the finished decorativesurface of the panel. Thereafter a relatively thin, continuous layer of mortar is placed, e.g. sprayed over the sculptured bed surface or the objects thereon and permitted to set. The spraying of the mortar with conventional spraying equipment results in a relatively rough, ragged surface which is highly desirable to obtain an optimal bond between the mortar layer and concrete subsequently poured into the form to complete the panel. Furthermore, the spraying of the mortar layer does not destroy the sculptured pattern in the sand bed as may occur when the mortar is poured over the sand bed without the utmost of care.  
  Once the mortar layer has set workmen can walk thereon and concrete reinforcing bars, e.g., steel bars are placed in the space of the form overlying the mortar layer. The form is then filled with concrete. The relatively rough surface of the mortar layer greatly facilitates the formation of a strong bond between the mortar and the concrete. After the concrete has hardened the form is stripped from the panel, removed from the sand bed and the resulting decorative surface is cleaned by washing it down with a jet of high pressure water. This completes the manufacture of the panel and it is thereafter installed by anchoring it to the ground, foundation, adjoining wall sections and the like.  
  In accordance with another aspect of the invention an adhesive agent is incorporated in the mortar mix before it is placed over the sculptured granular bed or the objects on such bed. A wide variety of adhesive agents are available. The essential characteristic of such agent is that it is compatible&#34; with the watery mortar slurry, that is that the adhesive agent can be evenly dispersed throughout the mix. The agent further must be curable&#34; in the mortar slurry, that is it must set up, cure or harden after it has been incorporated in the mix.  
  A wide variety of adhesive agents can be employed. For example, one may use polyvinyl, alcohol-polyvinyl acetate copolymers (or either one alone) such as CON- CRESIVE No. 1069 available from the Adhesive Engineering Company of San Carlos, Calif. or DARA- WELD available from the W. R. Grace Company of Boston, Mass; styrene butadiene emulsions such as SM-IOO available from the Highway Products Sales Division of Dow Chemical Co. of Midland, Mich.; acrylic emulsions such as CONCRESIVE No. 1198 available from the Adhesive Engineering Company; or epoxy Portland cement admixtures such as EPI-TOP PC-lO available from the Celanese Coatings Company of Louisville, Ky. or EPOXON available from the Epoxon Corporation of San Carlos, Calif. The bonding strength of such adhesive agents is enhanced by mixing them with up to 50 percent BERYLEX, a powdery substance available from the Harry Warde Co. of Kansas City, M0. The chemical composition of BERYLEX is not known to applicant.  
  A suitable, presently preferred adhesive agent is available from the United States Rock Company of 599 North Matilda Avenue, Sunnyvale, Calif. 94086 under the trademark ROCK BOND.  
  The incorporation of the adhesive agent facilitates the manufacture of the surface sculptured decorative structural building panels in several ways. The adhesive agent greatly increases the bond between the decorative surface objects, e.g. rocks and the structural con crete panel. I-Ieretofore experienced bond failures could result in loosening of individual rocks, which not only distracted from the appearance of the panel but which could endanger life or property and which required tedious, time-consuming and expensive repairs. Furthermore, the incorporation of the adhesive agent appears to enhance the speed with which the mortar sets up. Applicant is presently not certain what causes this speed-up in the set-up process. Additionally, the incorporation of the adhesive agent seals the pores of the mortar layer, prevents moisture from seeping behind the rock facing and thus prevents interior damage, the growth of microorganisms and a subsequent loosening of the bond between the rock and the mortar.  
  The shortened set-up time for the mortar layer is of great practical benefit since it enables the completion of a panel in a shorter time. Workmen can step on the mortar layer after a relatively short period of time to place the reinforcing rods for the later-poured concrete without disturbing the sculptured side of the panel. Consequently, forms can be reused more frequently, thereby making the manufacture of the panels more economical.  
  Further aspects of the invention relate to detailed refinements in the manufacture of the panels. Thus, it is preferred to employ granules rather than fine sand having a minimum size of no less than about A X U. S. mesh and no greater than about /8 X 6. After the rock has been placed on the granular bed the sides of the rocks facing away from the bed can be cleaned by washing them down. If the bed is made of sand fine sand particles have a tendency to splash back onto the rocks. The presence of such particles when the mortar layer is poured distracts from the quality of the bond between the rocks and the mortar. The relatively large granules, however, are too heavy to splash back under the impact of a stream of cleansing water so that maximum adhesion between the rocks and the mortar is assured. For instances in which the rock facing comprises relatively large and heavy rocks anchoring cones can be secured, e.g., bonded to the sides of the rock over which the mortar is applied. These cones preferably comprise truncated cones with the truncated end attached to the rock and the cone base being free and embedded in the mortar layer. Furthermore, coloring agents can be incorporated in the mortar to further enhance the appearance of the decorative face of the panel.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a building wall made with structural wall panels having a sculptured, decorative facing constructed in accordance with the invention;  
  FIG. 2 is a side elevational view, in section, of a form for pre-casting the panels illustrated in FIG. 1 in accor dance with the present invention;  
  FIG. 3 is a view similar to FIG. 2 but illustrates another aspect of the present invention; and  
  FIG. 4 is a view similar to FIG. 2 and illustrates the use of anchoring cones on panels having sculptured surfaces defined by relatively large rock plates.  
 I DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an upright building wall 2 is made from a plurality of building wall sections or panels 4 placed side-by-side and suitably anchored with bolts, concrete and the like. Each panel includes a structural concrete slab 6, a sculptured, decorative outer face or surface 8 and a mortar layer 10 which secures the decorative face to the concrete slab. The decorative face may be defined by a suitable design such as surface undulations 12 in the mortar layer or by regularly or irregularly shaped and positioned objects such as rock plates 14 which are bonded to the concrete slab with the mortar layer 10.  
  Each panel 4 is pre-formed by casting it in a horizontally disposed form 16. For the panels illustrated in FIG. 1 the form has a rectangular configuration although it will be understood that the form may have any other desired shape as dictated by the building, a particular decorative effect that is to be achieved or the like. The form is an open form as above defined and has vertical sides 18 and open ends or faces 20 and 22. Initially a bed of a granular material 24 such as the abovementioned gravel is formed on ground 26. In the embodiment illustrated in FIG. 2 the gravel bed is formed after form 16 has been placed on the ground and is entirely disposed within the form. In another embodiment, illustrated in FIG. 3, the gravel bed is first formed on the ground and the form is then placed on top of upper surface 28 of the bed.  
  Assuming now that the decorative face of the panel shall be rock plate, individual plates such as flag stones 30 are placed onto the upper gravel surface 28 and are preferably pushed into the bed to anchor or embed them therein and prevent their shifting. The flag stones are placed in the gravel bed in the desired array and they may overlap each other as is illustrated in FIG. 4.  
  After all rock has been placed in the mold essentially conventional mortar mix is made from mixing sand, cement and water, in conventional proportions. To this mixture the above-described adhesive agent is added. When the mortar is made in a conventional I0 cubic foot mortar mixer approximately 25 gallons of water, 5 sacks of cement (of -100 pounds each) and 4 to 6 cubic feet white sand (Olympia two type) are mixed. To this about 2 gallons of the above-referenced adhesive agent are added. This amounts to approximately 0.027 percent by volume of mortar slurry in the mixer. Acceptable results are achieved by placing as little as about one quart of the adhesive agent in the 10 cubic foot mixture or as much as about 5 gallons although a marked decrease in the bonding strength of the set mortar is experienced when the lower limit of adhesive proportion is reached. The upper limit is primarily detcrmined by economic considerations due to the relatively high price for the adhesive agents. The upper limit is further defined by the increasing viscosity of the resulting mortar-adhesive agent mixture and a resulting increasing difficulty in handling the mixture.  
  The mortar-adhesive mixture (hereinafter also referred to as mortar) is now placed, e.g., sprayed under pressure over the upwardly facing sides 32 of the flag stones until a continuous mortar layer of a mini mum thickness of about %;-inch and preferably of between /2 to fli-inch is obtained. This mortar layer covers and interconnects all facing rocks and any gaps that may exist between them.  
  After the mortar layer has been permitted to set up (normally for about 6 to 12 hours) it has sufficient strength and hardness so that workmen can step thereon. Next conventional concrete reinforcing bars 34 are placed into the form. It will be noted that the positioning of the reinforcing bars is facilitated by the fact that workmen can step on the mortar layer without breaking it or disturbing the arrangement of facing rocks 30. Thereafter, the form is filled with concrete and the concrete is permitted to set. It will be observed that the height of form walls 18 is such that the resulting concrete slab 6 has the necessary thickness. After the concrete has set the form is stripped by removing form sides 18 or opening the sides in cases where hinged, reusable forms are employed.  
  The finish cast panel is now raised from gravel bed 24, placed in its upright position and the decorative face 8 of the panel 4 is washed down with highpressure water to remove sand and gravel that may have become lodged thereon. The panel is now ready for placement in and anchoring to building wall 2.  
  Referring briefly to FIG. 3, in another embodiment of the invention the decorative face 8 of panel 4 is defined by the panel itself rather than by flag stones or other objects adhered to the panel. The surface may, for example, be defined by a pattern such as undulations 12 which are raked, formed or pressed into the upper gravel bed surface 28. Normally, such undulations in a gravel or a sand bed are destroyed when concrete is poured thereon. In accordance with the present invention the above-referred to mortar mixture is sprayed onto the sculptured sand surface to define a relatively thin mortar layer which has a thickness substantially less than the overall thickness of the finished wall panel and which is further preferably between about k to about fivinch. After the mortar layer has set up workmen can again step onto it to place the concrete reinforcing bars 34 in the form. As above de&#39; scribed the mold is thereafter filled with concrete and after the concrete is set the form is stripped from the panel and the panel is lifted off the sand bed. The decorative panel surface, now defined by the mortar, is washed down with a high pressure water stream to remove therefrom sand or gravel particles that may adhere to it.  
  Referring now briefly to FIG. 4, in instances in which the facing rocks are of a relatively large size, and, therefore, large weight, anchoring cones 36 are bonded to the upwardly facing sides 32. The anchoring cones may be constructed of any suitable material such as concrete, plastic, steel or the like and they are preferably bonded to the rocks with a suitable high strength epoxy. The cones are truncated cones with a truncated end 38 bonded to the rock and a free cone base 40 disposed in and anchored to the mortar layer 10. The anchoring cones supply additional holding force for the heavy rock plates to insure their secure adhesion to the mortar layer and the concrete slab.  
 I claim:  
  1. A method for making a building panel having a decorative face comprising the steps of providing a form defining the outline of the panel, forming a flat bed of a loose granular material, placing the form onto the bed, giving an upper surface of the bed a sculptured configuration, thereafter placing onto the sculptured surface a mixture made from. water, sand, a binding agent activated by the water and an adhesive compatible with and dispersable in water, permitting the mixture to set, thereafter filling the form with concrete, permitting the concrete to set, and removing the resulting panel having a sculptured surface from the mold and the bed.  
  2. A method according to claim 1 wherein the step of forming the surface configuration comprises the step of placing objects onto the sand, and wherein the step of placing the mixture onto the surface comprises the step of covering the objects with a layer of the mixture.  
  3. A method according to claim 2 wherein the step of placing the object comprises the step of placing objects in overlapping relationship onto the bed.  
  4. A method according to claim 3 wherein the step of placing the object comprises the step of placing rocks onto the bed.  
  5. A method according to claim 2 wherein the step of placing the objects comprises the step of partially embedding the objects in the bed.  
  6. A method according to claim 1 wherein the step of forming the bed comprises the step of forming a bed of gravel.  
  &#39;7. A method according to claim 1 wherein the step of placing the mixture comprises the step of placing the mixture to a minimum depth of approximately one-half inch.  
  8. A method according to claim 1 wherein the step of giving the surface configuration comprises the step of forming a pattern of depressions and protuberations in the bed, and wherein the step of placing the mixture comprises the step of covering the pattern in the surface with a layer of the mixture.  
  9. A method according to claim 1 including the step of placing concrete reinforcing bars in the form spaced from the layer prior to the step of pouring the concrete.  
  10. A method of constructing building panels having a decorative face comprising the steps of forming a horizontal bed of a granular material, placing an open form over the bed, sculpturing an upper surface of the bed, placing a relatively thin layer of a mortar into the form to cover the sculptured surface, the layer having a thickness of at least about one-half inch, permitting the layer to set, placing reinforcing bars spaced from the layer in the form, thereafter pouring concrete into the form, permitting the concrete to set, and thereafter removing the form from the poured mortar-concrete panel and removing the panel from the bed.  
  11. A method according to claim 10 wherein the step of placing the form comprises the step of placing the form on top of the bed.  
  12. A method according to claim wherein the step of placing the form comprises the step of forming the granular bed in a lowermost portion of the form.  
  13. A method according to claim 10 including the step of subjecting the decorative face of the finished panel after the panel has been removed from the bed to a stream of a high pressure fluid to remove from the face granular material that may adhere to the panel.  
  14. A method according to claim 13 wherein the step of subjecting comprises the step of subjecting the face to a high pressure stream of water.  
  15. A method according to claim 10 wherein the step of forming the surface configuration in the bed comprises the step of placing objects that define the face and the configuration of the face onto the bed surface, and wherein the step of placing the mortar comprises the step of covering the objects with a continuous motar layer.  
  16. A method according to claim 15 including the step of washing upwardly directed surfaces of the objects with water to remove substantially all granular materials from such surfaces.  
  17. A method according to claim 16 wherein the step of forming the bed comprises the step of forming a bed of gravel to facilitate the washing step, the gravel having a minimum average size of approximately A X 10 to X 6 U. S. mesh.  
  18. A method according to claim 10 including the step of adding to the mortar an adhesive material compatable with and curable in a water-based mortar.  
  19. A method according to claim 18 including the step of adding a coloring agent to the mortar before it is placed into the mold.  
  20. A method of constructing a structural building wall having at least one sculptured, decorative surface comprising the steps of forming a substantially horizontal bed of a granular material, placing an open form over the bed, placing onto the bed within the outline of the form objects that are to define the sculptured face, arranging the objects in the desired pattern, cleaning sides of the objects facing away from the bed of granules and debris, making a mortar by mixing a granulate, a water-activated binder, water, and an adhesive agent compatable with and curable in a watery slurry, covering the objects and the bed with a relatively thin mortar layer, curing the mortar, thereafter placing concrete reinforcing bars in the molds and placing a layer of concrete on top of the mortar layer, the concrete layer having a thickness substantially greater than the thickness of the mortar layer, curing the conrete to form a mortar-concrete panel having at least one sculptured surface defined by the objects, thereafter removing the form from the panel and removing the panel from the bed, cleaning the side of the panel including the sculptured surface of granules from the bed that may adhere thereto, positioning the panel in its vertical orientation at a building wall, and anchoring the panel to thereby complete the portion of the building wall defined by the panel.  
  21. A structural, water impervious building wall having a sculptured surface comprising a reinforced concrete slab, a mortar layer on one side of the slab having a thickness substantially less than the thickness of the slab, the mortar layer including an adhesive material compatable with and curable in a mortar slurry, the adhesive being evenly distributed throughout the mortar layer to enhance the adhesion of the layer to the slab and close voids in the layer to thereby render it water impervious, and a plurality of objects having first inner sides adhered to the mortar layer and second, exterior sides defining the sculptured surface, the mortar layer comprising a continuous layer between the objects and the slab.  
  22. A wall according to claim 21 wherein the objects comprise rock.  
  23. A wall according to claim 22 wherein the rock comprises relatively flat rock sections, at least some of the sections overlapping each other.  
  24. A wall according to claim 22 including a plurality of anchoring means secured to the side of the rocks adhered to the mortar layer and extending into the mortar layer to enhance the connection between the layer and the rocks.  
  25. A wall according to claim 24 wherein the anchoring means comprises truncated cones having a truncated end adhesively attached to the side of the rocks facing the mortar layer and a free cone base disposed in the mortar layer.