Abstract:
A method of forming a composite panel with a facade comprising a planar arrangement of thin discrete facers on a body of structural backing material. The method comprises the steps of providing a horizontal casting bed, providing a plurality of facers each with chamfers at corners between side-rear and end-rear walls, arranging the facers in abutting relationship atop the casting bed and in a selected pattern in a face down planar configuration so that the chamfers on the facers open upwardly and define narrow elongated sealant channels at joints between contiguous facers. Depositing a sealant in the channels and pouring concrete as a structural backing material atop the facers, the rear surfaces of the facers and the concrete adhering to form a composite panel.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a Continuation in Part and claims the benefit of U.S. patent application Ser. No. 09/772,633, filed Jan. 30, 2001, the disclosure of which is herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention is directed to a method of forming a composite panel with a facade comprising a planar arrangement of thin discrete facers on a body of a structural backing material. 
     BACKGROUND OF THE INVENTION 
     Composite concrete and other panels have been in use for a number of years but have not been entirely satisfactory. A bare concrete panel, for example, may be found lacking aesthetically or in other characteristics such as resistance to certain chemicals, durability, excessive heat gain from the sun, dirt or grime resistance, etc. Accordingly, a number of methods have been proposed to finish the front surfaces of panels in order to improve their aesthetic and architectural appearance and other properties. 
     For example, a number of different methods have been tried to cast in place or otherwise adhere discrete facing units or “facers” on the front surfaces of panels in finished concrete structures. As is well known, different methods have been employed in holding individual facers in a desired pattern, usually in a common horizontal plane, while concrete is cast over and about their rear surfaces so as to at least partially embed them in a wall or other panel. Facers such as thin concrete units manufactured on masonry block machines may be employed in accordance with the present invention together with bricks, tiles, natural stone, concrete pavers, etc. to provide a visually pleasing appearance or to meet functional requirements. 
     In manufacturing composite walls, in particular, it has been a conventional practice to provide various types of forms, grids etc. in securing the facers in face-down position prior to casting concrete or other structural material thereover. However, such methods have not been wholly satisfactory. For example, downward leakage of concrete between facers may result in concrete adhering to the front faces of the latter and in substantial added expense in subsequent removal thereof. Such prior methods have also failed to achieve economic advantage due to complicated and tedious manual steps involved in assembling and removing forms, grids, etc. Obviously, grouting between facers is also required in some designs when the panel is complete. 
     It is a general object of the present invention to provide a simplified method for making high quality composite walls and other panels at economic advantage, which yet results in a clean aesthetically pleasing final appearance and/or improved functional surface of the facer surfaced wall or other panel. 
     A further object of the invention resides in a method of making a composite panel which obviates the need for grouting between facers mounted on the panel. 
     A still further object is to provide a simplified method which requires an absolute minimum manpower requirement and yet results in panels pleasing in appearance and/or improved functional characteristics and a high degree of structural integrity. 
     SUMMARY OF INVENTION 
     In fulfillment of the foregoing objects and in accordance with the present invention, a method of forming a composite wall or other panel with a planar arrangement of thin discrete facers on a sturdy structural backing material comprises the steps of providing a flat preferably horizontal casting bed which may be of either a rigid or slightly deformable material. The ability of a casting bed to deform slightly allows the arrangement of facers accurately in a common plane despite irregularities which may occur on their front surfaces. Plastic foam or other similar materials may be employed in forming such a casting bed as well as a fine particulate material such as sand. When facers with smooth flat surfaces lacking any significant irregularities are employed, a rigid or hard surface casting bed may of course be employed preferably with a heavy paper, plastic sheet or very thin plastic foam thereover. 
     A plurality of facers each with a chamfer, bevel, or other recess along at least a major portion of the edges or corners between its side walls, end walls and rear wall are provided and arranged with the facers on the casting bed in abutting relationship face down. Various geometric patterns may be employed but the facers are in all cases positioned in a face down attitude and in a common plane, so that the aforesaid chamfers or other recesses are adjacent each other and open rearwardly or upwardly to define narrow elongated channels at joints between contiguous facers. Certain of the channels with two adjacent opposing chamfers may take “V” configurations in cross-section while others with only one chamfer may take one half (½) “V” configurations in cross-section. 
     In addition to the foregoing, sealant may be placed in the elongated recesses or channels and may also take a variety of forms. For example, elongated unitary sealing members, hardenable liquids, or fine particulate materials such as sand may be used, the latter being presently preferred. A castable structural backing material such as concrete or other cementitious material is then placed or poured rearwardly of the facers and both conforms to and adheres to the rear surfaces thereof as it cures and hardens. A composite wall or other panel is thus formed and may thereafter be moved to its operative position. For example, if the panel takes the form of a tilt-up wall poured horizontally, a simple upward swinging movement through 90° may be effected from its horizontal casting bed. 
     Channels provided adjacent joints may be filled with sand, for example, prior to casting concrete thereover and the sand may later be washed or blown out of the channels to provide drainage channels to prevent water accumulation behind the facers. 
     Generally, the facers have a rectangular configuration and the rear corners thereof are beveled or chamfered at edges or corners between each end wall and rear wall and at least one side wall and rear wall. Chamfers or other recesses may take various configurations viewed in cross-section including rectangular and arcuate, but a flat angularly inclined surface extending between adjacent right angularly related side or end and rear facer surfaces is preferred. When a sealant such as sand is employed, a subsidiary method step may take the form of depositing sand on the rear surfaces of the facers and sweeping the same into the sealant channels with the remainder of the facer rear surfaces being cleaned for good adhesion of the concrete. 
     Preferably, the rear surfaces of the facers are also provided with integral rearwardly and upwardly projecting structural connecting means which are enveloped during the pouring of concrete and thereafter firmly embedded in the cured concrete for enhanced structural integrity of the wall or other panel. Such walls or other panels are found to be substantially stronger than walls or panels without facers and may even approach the strength of monolithic concrete walls or panels of equal overall thickness. The connecting means presently take the preferred form of a series of spaced apart rearwardly projecting parallel ribs integral with the bodies of the facers. Further, the ribs are preferably formed as shown in the drawings with dove-tail configurations in cross-section defining complementary generally dove-tail grooves therebetween. 
     Still further in accordance with the preferred form of the invention, a plurality of spring clips are provided to interconnect the aforementioned ribs. Some of the clips may be installed in interconnecting relationship on aligned ribs of contiguous facers arranged in end-to-end relationship and others on contiguous half ribs arranged in side-by-side relationship on adjacent facers in like relationship. The clips are preferably of generally dove-tail configuration viewed in cross-section with short opposing side legs defining entry openings for the dove-tailed ribs. Further, the legs of each clip are inwardly inclined toward the mouth of the clip opening so that the clips may be snapped into firm embracing engagement on the ribs in relative movement toward the ribs. Thereafter the clips serve to urge facers and especially the side-by-side facers firmly together in abutting engagement to prevent concrete leakage downwardly there-between. 
     Further, the clips also help to maintain the facers in a common plane preventing accidental or unintended displacement of individual facers. Still further, the clips aid in urging facers having uneven front surfaces and facers improperly positioned toward a common plane. 
     A tool of appropriate design may also be provided for ease of convenience in the assembly of the clips on the ribs. 
     Finally, a plurality of upstanding anchors may be provided with base portions mounted on the ribs of the facers and supports for horizontal reinforcing members such as “re-bars” may also be provided with the latter also mounted on rear surfaces of the facers in engagement with ribs and inter-rib grooves. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a “facer” constructed in accordance with the present invention. 
     FIG. 2 is a front view of the facer of FIG.  1 . 
     FIG. 3 is a view taken from the end of the facer. 
     FIG. 4 is a perspective view of the rear surface of the facer. 
     FIG. 5 is a side view of a partially constructed wall with facers disposed atop a casting bed of sand in abutting relationship and with one-half (½) “Y” sealant channels between facers. 
     FIG. 6 is a fragmentary enlarged view of a facer joint taken from FIG.  5 . 
     FIG. 7 is a view similar to FIG. 5 but with sand disposed in the sealant channels. 
     FIG. 8 is a fragmentary enlarged view of an inter-facer joint as in FIG. 6 but with sand deposited in the sealing channel. 
     FIG. 9 is a side view similar to FIGS. 5 and 7 but with concrete deposited atop the facers. 
     FIG. 10 is a fragmentary enlarged view of a facer joint as illustrated in FIG.  9 . 
     FIG. 11 is enlarged fragmentary view of a facer joint as in FIG. 6 but with an Y-shaped sealant channel. 
     FIG. 12 is similar to FIG. 11 but with sand deposited in the channel as a sealant. 
     FIG. 13 is a view similar to FIGS. 11 and 12 but with structural material deposited atop the facers. 
     FIG. 14 is a perspective view of a plurality of facers positioned in face down abutting relationship and partially forming the front section of a panel, spring clips being mounted on ribs which project upwardly from the facers. 
     FIG. 15 is an enlarged perspective view showing an individual spring clip. 
     FIG. 16 is a top view of an alternative dip. 
     FIG. 17 is a perspective view of the spring clip of FIG.  16 . 
     FIG. 18 is a side view of the spring dip of FIGS. 16,  17 . 
     FIG. 19 is a side view of an anchor adapted to be mounted on a back surface of a facer. 
     FIG. 20 is an opposite side view of the anchor of FIG.  19 . 
     FIG. 21 is a perspective view of the anchor of FIGS. 19 and 20. 
     FIG. 22 is a top view of the anchor. 
     FIG. 23 is a top view of a “chair” for supporting elongated concrete reinforcing members or “re-bars”. 
     FIG. 24 is a perspective view of the re-bar chair of FIG.  23 . 
     FIG. 25 is a side view of the chair. 
     FIG. 26 is another side view better showing an upwardly open groove for receiving and supporting a re-bar. 
     FIG. 27 is a perspective view showing a number of facers with chairs mounted thereon as in FIGS. 23-26, the chairs being shown with their legs spring mounted in the dove-tail grooves of the facers. 
     FIG. 28 is a side view showing the chair supporting right angularly arranged re-bars. 
     FIG. 29 is an enlarged perspective view showing a chair mounting a pair of right angularly arranged re-bars. 
     FIG. 30 is a top view of a chair having three mounting grooves arranged in alignment with three opposite grooves; thus, three re-bars being accommodated in right angular arrangement with three additional re-bars. 
     FIG. 31 is a perspective view of the re-bar chair of FIG.  30 . 
     FIG. 32 is a first side view of the re-bar chair of FIGS. 30 and 31. 
     FIG. 33 is a second and opposite side view of the chair. 
     FIG. 34 is a perspective view of the chair of FIGS. 30-33 with a single re-bar mounted thereon in each right angular direction and with the base portion of the chair mounted in embracing relationship on ribs on the back of a facer. 
     FIG. 35 is a perspective view similar to FIG. 34 but with a base portion of the chair entered in and engaging the opposite side-walls of an inter-rib groove. 
     FIG. 36 is a perspective view showing a number of facers with an anchor and a large chair having three aligned grooves in one direction and five aligned grooves in right angular arrangement therewith. 
     FIG. 37 is a side view of a tool for installing spring clips with an associated clip shown in an expanded condition. 
     FIG. 38 is a similar view of the same tool with the clip in a contracted position. 
     FIG. 39 is a perspective view illustrating operation of the tool in respect to a spring clip. 
     FIG. 40 is a top view of the tool of FIGS. 37-39; 
     FIG. 41 is a perspective view of an insulated panel constructed in accordance with the method of the present invention, 
     FIG. 42 is a foam plastic mat in a corrugated configuration for use as a casting bed, 
     FIG. 43 shows the mat of FIG. 42 with facers placed thereon in abutting relationship, 
     FIG. 44 is a perspective rear view of a facer provided with a drainage channel along its rear top edge portion, 
     FIG. 45 is a view similar to FIG. 44 but with an improved drainage channel and a front to rear drainage notch, at a top edge portion thereof, 
     FIG. 46 is a view similar to FIG. 45 but showing only a front to rear drainage notch, 
     FIG. 47 is a top view of an end cap unit, 
     FIG. 48 is a perspective view of a portion of adjoining wall sections employing the end cap at a right hand 90° corner between the wall sections, 
     FIG. 49 is a right angular 90° corner unit, 
     FIG. 50 is a perspective view of wall sections arranged at right angles and employing the corner section, 
     FIG. 51 is a corner facer unit employing a 45° mitered end surface, 
     FIG. 52 is a perspective view of wall sections arranged at right angles and employing the corner unit of FIG. 51, 
     FIG. 53 is a rear perspective view of a facer unit having an enlarged 45° mitered end surface, 
     FIG. 54 is a rear view of a 90° corner section of a wall employing adjoining corner sections shown in FIG. 53, 
     FIG. 55 is a rear perspective view of a heavy duty facer unit usable as a marginal member in windows and other wall openings, 
     FIG. 56 is a perspective view of a wall with an opening employing a unit of FIG. 55, 
     FIG. 57 is a perspective of a cap unit, and 
     FIG. 58 is a side view of a cap unit in assembly with a facer unit and associated concrete backing. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now particularly to FIGS. 1-4, a facing unit or “facer” is illustrated generally therein at  10  in a presently preferred form. As mentioned above, facers may take a wide variety of forms including thin concrete units capable of formation in masonry block machines, conventional bricks, concrete pavers, natural stone etc. The facer  10  shown is of the concrete type formed in a masonry block machine and has a decorative face or front wall  15  of pleasing appearance as best illustrated in FIG.  2 . The facer also has at least one recess and preferably two recesses in the form of beveled or chamferred edges or corners  12 ,  12  between the end walls  11 , 11  and rear wall  17  and along one side wall  9  and rear wall  17  edge or corner. The opposite rear wall side wall edge or corner  13  is devoid of a bevel or chamfer as best illustrated in FIGS. 3 and 4, this due to the inability of block machines to conveniently form chamfers on all four rear corners of the facers. 
     Connecting means for co-operation with concrete or other structural backing material on the rear surface of the facer preferably take the form of integral dove-tail ribs as shown. A single centrally located full rib  14  is shown in FIG.  1  and partial, approximate parallel half ribs  16 ,  16 , are also shown in FIG. 1 on opposite sides of the rib  14 . Dove-tail grooves  18 ,  18  are defined between ribs as best illustrated in FIGS. 1 and 4. 
     Referring now to FIGS. 5 through 10, the method of the invention will be illustrated and described sequentially. In FIG. 5 a plurality of facers  10 ,  10  are shown positioned in abutting face down relationship and in a common plane atop casting bed  20 . The casting bed  20  may be rigid or deformable as mentioned. Foam plastic and other materials may be employed in a deformable bed but fine particulate material, such as sand is shown in FIGS. 5 through 10. Form members  22 ,  22  establish the marginal limits of the casting bed. Channels defined between facers are at least one-half (½) “Y” configurations viewed in cross-section and may accommodate sealant as mentioned. As best illustrated in FIG. 6 a chamfer  12  on a right hand facer forms a one-half (½) “Y” channel with the straight face of a left hand facer adjacent thereto. 
     In FIGS. 7 and 8, a sealant has been introduced to the channels  24  and may comprise a fine particulate material, preferably sand  26  as mentioned above. This may be conveniently accomplished by depositing sand atop the backs of the facers, sweeping the same into the sealant channels  24 ,  24  and concurrently sweeping the sand away to clean the backs of the facers for good adherence to the concrete. 
     FIGS. 9 and 10 illustrate the facers  10 ,  10  with a cementitious structural member cast thereabove, conforming to and adhering thereto. Concrete is preferably employed as mentioned but various other materials capable of being cast in situ may also be used. As best illustrated in FIG. 10, the concrete is formed about the ribs  14 ,  16  and at the joints there between. Downward penetration of the concrete between facers during pouring and curing is prevented by the sand  26  which forms a seal between the facers as stated. 
     In FIGS. 11-13, joints  24   a ,  24   a  are shown between facers  10 ,  10 . The “Y” shaped sealant channels shown obviously result where adjacent facers are provided with identical but opposing chamfers  12 ,  12 . The method employed is identical with that of FIGS. 5 through 10. That is, sand is introduced to the channels as shown at  26  in FIGS. 12 and 13. The excess sand may then be swept clean and the concrete or other cementitious material  28  poured and allowed to cure and harden as shown in FIG. 13, the sand  26  serving its sealing function in each of the channels as stated. Thus, concrete is prevented from penetrating downwardly and defacing the front surfaces of the pavers. 
     As a substitute for sand, a casting bed with a degree of deformability can also be provided with foam plastic as illustrated in FIGS. 42 and 43. Expanded polystyrene is presently a preferred material and may be advantageously employed in a corrugated form as shown in FIG.  42 . Facers are placed on the plastic bed in an inverted attitude and in abutting relationship as with the sand bed above and as shown in FIG.  43 . Excellent results have also been achieved with this alternative. 
     In FIG. 14, a plurality of facers  10 ,  10  are shown in a partially complete panel in association with optional spring clips  30 ,  30 . The spring clips  30 ,  30  each have a dove-tail configuration complementary to the cross-section of the ribs  14 ,  16 . That is, a single central rib  14  can be interconnected with clips to a second rib  14  in end-to-end relationship as shown. Further, end ribs  16 ,  16  in side-by-side relationship can also be readily interconnected by clips  30 ,  30  as shown. The clips may be entered about a single rib  14  or a pair of adjacent end ribs  16 ,  16  in relative endwise movement and positioned as desired to serve their interconnecting function. Preferably, however, the clips are urged downwardly over and into engagement with the ribs with opposite legs  32 ,  32  first being spread apart and then contracting in a snap action to firmly embrace the ribs. 
     FIGS. 16-18 illustrate a second embodiment of the clips at  30   a  and it will be observed that each of the clips includes openings as at  34  in FIGS. 14,  15  and  34   a  in FIGS. 16-18. The openings  34  and  34   a  allow concrete to penetrate downwardly and adhere to the aforementioned ribs  14 ,  16  during pouring and subsequent curing. 
     The installation of the clips may be accomplished manually as mentioned or with the aid of a tool  36  illustrated in FIGS. 37-40. The tool  36  has manually operable handles  38 ,  38  pivotally connected at  40  and opposed operating arms  42 ,  42  each with a small outwardly directed lip  44 . The lips  44 ,  44  engage small inwardly extending hook-like members  46 ,  46  at the ends of the legs of a clip  30  to spread the legs  32 ,  32  of the clips for easy positioning of the same about a rib. Once a clip has been positioned about the rib the tool may be released to allow the legs to spring inwardly and snap into firm embracing relationship with one or more ribs. FIG. 38 shows the release of the clip and the vertical movement of the tool is illustrated in FIG.  39 . Once the clips have been installed as shown in FIG. 14, pouring of the concrete may be initiated as described above. 
     The clips  30 ,  30   a  may be employed to ensure firm abutting engagement of the facers in the embodiment described above with a sealant disposed in the recesses or channels at facer joints. Further, satisfactory results may be achieved with the clips in some cases even without sealant disposed in the channels between facers. That is, the forces provided by the clips urging the facers into engagement may result in joints between facers which are sufficiently tight to prevent penetration of the concrete through the joints and a resulting undesirable flow of small quantities of concrete onto front surfaces of the facers. These conditions may prevail when facers with particularly smooth surfaces are employed. Further, it may be possible to eliminate both the sealant and the clips in certain situations. Here again, manually abutting facers with exceptionally smooth side surfaces may result in joints sufficiently tight to prevent downward concrete penetration. 
     A product known as Self Compacting Concrete not requiring vibration may also be employed to advantage as a structural backing material particularly in this latter embodiment of the method. In the absence of vibration, which is required with conventional concrete for uniformity and for filling small voids, there is considerably less likelihood of penetration or leakage through the facer joints. 
     In addition to the foregoing, “anti bonding agents” and “retarders” may be applied to the front surfaces of the facers. This facilitates or may completely eliminate cleaning of the facers as a final step in the process of making the walls or other panels of the present invention. 
     In certain applications, additional strength may be required in connecting the facers to the structural backing material of the panel. FIGS. 19-22 illustrate an anchor  49  employed for this purpose. In FIG. 36 the anchor  49  is shown in operative position mounted on a facer prior to the casting of concrete thereabout. The anchor has a base portion  48  adapted to enter and fit a groove  18  as illustrated in FIG.  36 . An upwardly projecting portion is adapted to be embedded in the concrete and thereby provide enhanced strength securely interconnecting the facers and their structural backing. As shown, the base portion  48  takes a generally Z shape with opposing legs  52 ,  52  adapted to enter a groove  18  and firmly engage the opposing ribs which define the groove. The upper portion of the anchor includes an integral arm  50  which extends horizontally with the anchor mounted on the facers and which is embedded in the concrete as mentioned. 
     A support or “chair” for mounting elongated reinforcing members, commonly known as “re-bars”, is illustrated in FIGS. 23-29 at  54 . The chair  54  has four (4) legs  58 ,  58  and defines a pair of right angularly arranged upwardly open grooves  56 ,  56  at an upper portion thereof. The legs  58 ,  58  enter the grooves  18 ,  18  as best illustrated in FIGS. 27 and 29 and are preferably of flexible construction so as to bend inwardly and then snap into position. The reinforcing members or “re-bars”  61 ,  61  may then be mounted in the grooves  56 ,  56  as shown in FIGS. 27 through 29 prior to pouring the concrete so that both the chairs and the re-bars are thereafter embedded in the concrete. 
     FIGS. 30-35 illustrate another re-bar chair for supporting re-bars and for ease in locating the same. 
     In FIG. 41 an insulated panel is illustrated in cross-section and comprises a plurality of facers  106 ,  106  in planar arrangement as described above. A relatively thin layer of concrete  50  is then cast over the facers with a conventional insulating panel  52  disposed thereabove. Finally, a heavier layer of concrete  54  is cast atop the insulating panel with transverse connectors  56 ,  56  embedded in the concrete and preferably extending from the thin layer of concrete  50  through the insulating panel  52  and into the heavier layer of concrete  54 . 
     Once a wall or other panel has been constructed and erected using the foregoing method, drainage becomes an important consideration. The sand used in the channels during pouring of the concrete may then be removed for example by power washing from the front of the wall. Once the sand has been removed, the “Y” or half “Y” channels of FIGS. 6 through 12 provide for drainage in both horizontal and vertical directions adjacent facers. Absent power washing or other treatment to remove the sand, nature will also work to achieve the same channel cleaning result. Wind and rain beating against the facers and the joints therebetween will dear the channels over time. That is, rain will penetrate rearwardly through the joints between facers and wash the sand from the “Y” or half “Y” channels  26  leaving voids for the flow of drainage water. As stated above, water trapped behind facers may loosen and even force facers off the wall in freezing conditions. Water trapped behind facers may also gradually migrate forwardly and evaporate on the front surfaces of the facers. Salts in the water will, however, result in an unsightly efflorescent effect on the front facer surfaces. 
     In FIG. 44, a facer  10   a  is provided with an elongated auxiliary drainage groove  60  which is open at each end and resides in an upwardly open attitude near the top of the facer and adjacent the bevel or chamfer  12  formed along the top of the facer. At the center  62  of the groove  60  its bottom wall is elevated as shown and is inclined downwardly therefrom in opposite directions to enhance horizontal drainage flow toward the ends of the groove. 
     FIG. 45 illustrates a facer embodiment similar to the facer of FIG. 44 but provided with additional drainage features. Facer  106  has an auxiliary drainage groove  60   a  similar to the groove  60  of the facer  10   a  but with a low point and two spaced apart high points rather than one. High points  64 ,  64  are each approximately one fourth (¼) the length of the groove from adjacent groove ends and low point  66  is approximately at the center of the groove. Further, an upwardly open V-shaped notch  68  is provided at the center of the facer and communicates laterally with the groove and with the front surface of the facers. Thus, drainage water will flow both toward the ends and the center of the groove  60   a  and at the center it will drain forwardly through the notch for discharge down the front face of the facer. When facers are arranged in the usual “running bond” or staggered relationship, it will be noted that the V-shaped notch will align vertically with adjacent vertical bevels or chamfers for a pleasing effect aesthetically. 
     FIG. 46 illustrates a facer  10   c  provided with a central upwardly open notch  68   a  as in the case of the facer  10   b . Operation is as described for the facer  10   b  with regard to the notch with unwanted water draining forwardly and down the front surface of the facer. 
     As will be apparent, exposed end surfaces of walls or other panels will also require aesthetic treatment when the walls or panels are moved to their final positions. Thus, an “end cap” facer  70  as illustrated in FIG. 47 may be required and may take the form of a facer approximately one-half (½) the length of a conventional facer described above. As shown, the “end cap” facer  70  has a single dove-tailed rib  71  on its rear surface so as to be secured in the concrete or other backing material in right angular arrangement with the front surface of the wall or panel, FIG. 48. A left hand wall  72  in FIG. 48 may be positioned slightly forwardly so as to provide for the end cap facer with its front surface in a common plane, or alternatively, one or the other of the walls may be notched as required to provide for a co-planer arrangement. The left hand wall  72  in FIG. 48 will exhibit a vertical seam as shown but the right hand wall  74  will have the overall appearance of a conventional wall with staggered joints. The end cap facer may be cast in position as shown with its dovetailed rib embedded in the concrete. Alternatively, the end cap facer may be provided without a rib and adhesively secured in position. A vertical gap appears at the corner as illustrated at  76  absent an overlap relationship of the end cap facer with the concrete of the right-hand wall  74 . 
     A unitary right angular corner facer is shown in FIGS. 49 and 50 and provides an aesthetically pleasing corner without the vertical gap of FIG. 48, see FIG.  50 . Notching of the concrete or other backup material may be necessary depending on the thickness thereof. Secure mounting of the facer is provided for with structural ribs  76  and  78  adjacent opposite ends of the facer and an curved central portion  80  provides additional strength. As will be seen, vertical joints are provided adjacent each side of the corner as at  82  and  84  in FIG.  50 . 
     FIGS. 51 and 52 illustrate yet another method of corner treatment wherein facers such as  86  are provided at one end with a 45° mitered end surface  88 . Obviously, a clean aesthetically pleasing corner results as in FIG. 52 when the concrete backing is also provided with 45° mitered end surfaces. Conventional running bond configurations can be provided on facer surfaces of both adjoining wall surfaces when full and half facers are each provided with mitered end surfaces. 
     Another version of a corner facer with a mitered end surface is indicated generally at  90  in FIG.  53  and has a 45° mitered end surface  92 . In addition, one half of a dovetailed rib  94  is formed adjacent the mitered surface  92  and provides an enlarged mitered surface and also projects angularly rearwardly at 45° for cooperation with a similar rib  94  on an adjacent corner facer. The ribs  94 ,  94  together form a complete dovetailed rib  96  which projects angularly rearwardly as best shown in FIG.  54  and which may be employed with a complementary spring clip to secure two corner facers  90 ,  90  in assembly at right angles to each other. The facers may of course be clipped together and cast in place in method analogous to the units  80  in FIG.  49 . Alternatively, the facers may be adhesively secured together at their mitered surfaces  92 ,  92 . 
     FIG. 55 illustrates a facer  98  similar to the facers  10  et sequa but substantially thicker, approximately three (3) inches thick versus one (1) inch for the facers  10 ,  10 . The facers  98 ,  98  may find a variety of uses as for example as marginal elements in door and window openings in walls employing conventional facers  10 ,  10 . 
     In FIG. 56, a wall  100  defines a window opening  102  with a facer  98  employed as a sill member. Although not so illustrated, facers  98 ,  98  may also be employed as lintel and jamb members for improved appearance, resulting from the additional “set back” of the concrete backing material when viewed from the front. Corner units such as the FIG.  49  and FIG. 54 units may also be employed in forming window and door jambs for improved appearance. 
     A “cap block”  104  is illustrated in FIG.  57  and may find application as its name implies to form a cap along the top of a wall, FIG.  58 . Facers  10 ,  10  engage and support forward end portions of the blocks  104 ,  104  when the wall has been erected and rear portions thereof are supported by the concrete as shown with a series of small parallel dovetailed ribs embedded in the concrete. It should also be observed that the block  104  shown in FIG. 58 can be employed, for example, as a windowsill lintel or jamb members with the window or door opening defined thereby. 
     As will be apparent from the foregoing, a method has been provided for forming a composite panel of groutless construction in an extremely simple and yet highly efficient manner. The method may obviously be employed at economic advantage in the construction of composite tilt-up walls, precast and other panels having a wide variety of facial characteristics with a minimum of manual labor and an aesthetically pleasing and/or functionally improved end result.