Abstract:
A modular construction system utilizes building components or panels formed of high strength plasticized concrete. Panels are formed with two or more linear peripheral edges fitted with mortises. FRP pultruded tenons are used to connect aligned mortises for adjacent panels. Walls, crown beams and roof panels can be so formed and assembled. Hollow corrugated panels are suitable for forming beams and interior partitions. Beams can be rested on regularly spaced piles and then floor panels on the beams, walls on the floor panels, crown beams on the walls and roof panels on the crown beams, buildings can be erected with a minimum of tools or specialized knowledge. The resulting structure is substantially impervious to environmental hazards, particularly relevant in more primitive locations.

Description:
FIELD OF THE INVENTION 
     This invention relates to the modular construction of buildings and more particularly to the use of a modular system of load-bearing concrete panels and connectors to build housing. 
     BACKGROUND OF THE INVENTION 
     It is known to construct buildings using rigid frameworks such as wooden studs or steel girders, and providing external covering material such as wooden sheeting or concrete panels and internal coverings such as drywall. 
     The construction of such buildings is expensive and time consuming and requires special materials, tools and expertise. This is especially true for the construction of buildings that are fire-resistant and capable of withstanding tornadoes, earthquakes, moisture related damage and insect infestation. 
     It is also known to use modular systems, comprising prefabricated load-bearing panels. If created from concrete, such panels are often very heavy and have little insulating value. Insulation does not adhere well to concrete and the resulting panels are not composite in nature. Further surface finishing requires the use of craftsmen. 
     With an eventual shortage of natural building materials such as lumber and the lack of skilled craftsmen in many areas of the world, the current invention provides a modular, rapid, construction system that does not require conventional fasteners and is easily put together with minimal skill. 
     SUMMARY OF THE INVENTION 
     A modular construction system is provided for erecting buildings with a minimum of tools or specialized knowledge. The resulting structure and its&#39; material of manufacture ensure it is substantially impervious to environmental hazards, particularly relevant in more primitive locations. 
     High strength composite concrete panels utilize plasticized high strength concrete. The panels can be precision factory produced for hand assembly in the field and are provided in both corrugated and channel or ribbed forms. Panels can be pre-formed with openings such as window&#39;s and doors and have pre-finished surfaces. Light, hollow corrugated panels have a zigzag high strength concrete shape sandwiched and secured with adhesive between two flat high strength concrete panels. For panels applied to the building exterior, low-weight, ultra low tensile aerated concrete can be added between ribs as insulation and added rigidity. 
     The composite concrete panels integrate edge connection means which interlock to each other and to primary concrete building components such as complimentary pilings, wall footings, crown beams and roof purlin connectors. These connectors are particularly amenable for installation by hand. 
     As a result, structures, such as housing, can be erected on-site, with a minimum of equipment and without the requirement for craftsmen. 
     In one embodiment, the edge connection means comprise C-shaped FRP extrusion for forming a mortise about the periphery of the panels. For composite corrugated panels, the mortises are formed of extruded plastic, sandwiched between high strength concrete sheets. In channel panels and building components, the mortise preferably take the form of dovetail grooves formed directly in the panel&#39;s concrete. Each of the C-shaped or dovetail mortises accepts one lateral half of a pultruded epoxy, fiber-reinforced joiner or tenon insert having an X-shaped cross-section. When mortises of components and panels are facing or adjoining each other, they form a cavity into which these X-connectors can be inserted as a tenon, locking the components and panels, or panel to panel, together. Unlike concrete, the X-connector tenons are elastic and are forgiving of misalignment and movement. 
     Using the X-connector tenons, a floor channel panel having a downward facing groove can be locked to a piling having an upward facing and complementary groove. The bottom of a wall panel can be locked to the floor panel. A crown beam can be locked to the top of the wall panel and the bottom of a roof panel can be locked to the crown beam. 
     Preferably, the crown beam has a low profile by providing a greater lateral dimension than height. This unconventional orientation also aids in providing lateral strength to resist roof-spreading loads and transferring them vertically into the walls. Advantageously, the lateral extension also make it possible to secure exterior gutter and interior valences thereto, preferably using the same X-connector tenons. 
     Further, adjoining roof panels can be connected using purlin connectors having a deep depending rib portion for adding extra beam section and strength to the roof structure. 
     In the broadest form of the invention, a method of modular concrete construction comprises providing two or more lightweight composite concrete building components having one or more linear peripheral edges formed with linear dovetailed fitting mortises, providing one or more flaring tenons, aligning two adjacent building components with facing fitting mortises, and joining the aligned panels by inserting one or more of the flaring tenons along the peripheral edge and into the facing fitting mortises so that the panels cannot be separated. 
     Preferably this method is applied to the formation of walls panels for forming a walled structure, all of which are joined using the mortises and tenons. This method of construction can be extended to form a plurality of components for forming a wide crown beam which rests atop the walled structure and supports a plurality of roof panels resting thereon. 
     More preferably, additional building components such as floor panels can be similarly formed. Using the lightweight composite concrete, corrugated panels can be formed of a profiled or corrugated sheet glued sandwiched between two sheets. These corrugated panels, fitted with mortises, can be used a beams as part of a suspension system, resting on piles, or assembled as interior partitions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded cross-sectional view of one half of a modular building manufactured in accordance with a preferred form of the present invention; 
     FIG. 2 is an exploded view of the construction components of a building manufactured in accordance with the invention; 
     FIG. 3 is a perspective view of a building constructed using one embodiment of the invention and illustrating the concrete culvert detail; 
     FIGS. 4 a  and  4   b  are side and exploded fastener views respectively of the rock pile; 
     FIG. 5 is a plan view of a nine-pile grid; 
     FIG. 6 is a partial cross-sectional detailed view of the crown beam and interlocking to the roof and wall panels; 
     FIG. 7 is a partial cross-sectional detailed view of the crown beam with interlocked exterior gutter and interior valance; 
     FIG. 8 is a partial cross-sectional plan view of a 90° corner crown beam; 
     FIG. 9 is a partial cross-sectional view of part of the wall panels, the crown beam and roof panels accordingly to FIG. 1; 
     FIGS. 10 a-   10   d  illustrate the nature of the interior corrugated partitions. Specifically, 
     FIG. 10 a  is a overall arrangement illustrating a side view of a partition butted up to and illustrating a cross-section of an exterior wall; 
     FIG. 10 b  is a plan cross-sectional view detail showing the strip connector between the partition and the a complementary slot at the joint between two exterior wall panels; 
     FIG. 10 c  is a plan cross-sectional view detail showing the interlocking of adjacent partitions; 
     FIG. 10 d  is a side cross-sectional view of the top and bottom partitions illustrating capping and hook and loop fastener between the partition bottom and the floor; 
     FIG. 11 is a partial cross-sectional view of a corrugated panel; 
     FIGS. 12 a  and  12   b  are an end cross-sectional view and a side view of the X-connector; 
     FIG. 13 is a plan cross-sectional view of a vertical tongue joint illustrating a typical serpentine external wall panel joint; and 
     FIGS. 14 a-   14   h  illustrate structural framing details: 
     a. is a plan view of the building of FIG. 3; 
     b. is a cross-sectional view according to lines A—A of FIG. 14 a;    
     c. is a cross-sectional view according to lines B—B of FIG. 14 a;    
     d. is a plan cross-sectional view of a wall corner of FIG. 14 a;    
     e. is partial plan view of the hip and peaks of the building of FIG. 14 a;    
     f. is a cross-sectional view of the hip and peak sections of FIG. 14 e  along lines f—f; 
     g. is a cross-sectional view of the hip and peak sections of FIG. 14 e  along lines g—g; and 
     h. is an elevation view of the hip and peak connector of FIG. 14 e.   
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Overall, and shown generally in FIGS.  1 , 2 , and  3 , there is disclosed a concrete building  10  and method of construction of same which comprises a connecting a plurality of exterior walls  11 , a support or suspension system  12 , a floor  13  and a roof  14 , all of which are manufactured of composite concrete components. Individual building components  15  interlock with each other and with other building components with a consistent arrangement of dovetail-like mortises  16  and tenon connectors  17 . 
     It is instructive to first identify the building&#39;s major components and then describe them in greater detail thereafter. 
     As shown in overall FIGS. 1,  4   a  and  4   b,  a pile  20  comprising an epoxy-resin fiber-reinforced (FRP) auger  21  and a square milled top  22  form a suspension system  12  for use in soil footings. 
     Having reference also to FIG. 5, a rectangular suspension grid  30  is formed for a total of nine piles  20  in a 3-by-3 arrangement. A grid shaped pattern (not shown) can be employed to ensure accurate positioning of the piles  20 . Each pile  20  connects to and supports the ends of floor beams  31  spanning between piles  20 . Typically, six strong, three-ply floor beams  31  run end to end, in co-axially extending pairs, running parallel each other pair spaced by three pairs of transverse, single-ply, weaker floor beams  32 . Floor panels  13 , having a channel profile, span the entire length of the 3 piles  20  aligned perpendicular to the strong beams  31 . 
     Exterior walls  11  stand vertically from and interlock with the periphery of the floor panels  13 . 
     As shown in detailed FIGS. 6 and 7, a header or crown beam  40  interlocks with and extends about the top of the walls  11 . Exterior rain gutters  41  and interior valence and utility tray  42  are interlocked to and are supported from the crown beam  40 . 
     At wall corners, a 90° curved section  43  of crown beam  40 , seen in FIG. 8, is used to connect linear sections  40 . Interlocking, vertically tapered fingers  44  provide a connection to resist lateral separating forces. Internal reinforcement is provided using epoxy/fiberglass (FRP) pultruded reinforcing rods  45 . 
     Sectional roof panels  14  interlock with and are supported atop the crown beam  40  as seen in FIGS. 1 and 9. A cottage-style roof  14  is shown which extends vertically upwardly and then deviates laterally to approach the peak and a peak connector  46  at an angle. Best shown in FIG. 9, compound curved panels  47  provide the section of the roof  14  adjacent the crown beam  40 . Flat panels  48  constitute the balance of the roof panels  14 . Dependent upon the span of the roof  14 , flat roof panels  48  are occasionally interlocked to one another using a purlin connector  49 , providing a locally increased and strong beam section. 
     Interior partitions  50  shown in FIGS. 10 a-   10   d,  interlock at interfaces  51  between adjacent wall panels  11  and are attached to the floor panels  13 . 
     More specifically, three basic panel types are pre-formed using high strength concrete: a corrugated structural panel  60  for forming beams  31 , 32  and interior partitions  50 ; a channel form  61  for floor panels  13 ; and an insulated channel  62  for forming exterior wall  11  and roof panels  14 . 
     Corrugated Panels—Beams and Partitions 
     Having reference to FIGS. 8 and 10 a-   10   d,  panels  60  for partitions  50  and beams  31 , 32  are planer composite corrugated panels entirely constructed of a matrix of high-density, high strength, plastic and fiber-reinforced concrete (hereinafter “HS concrete”). 
     Concrete having strength of 5,000 psi or greater is preferred. As shown, each panel  60  can be readily factory mass-produced by forming of first and second planer sheets  70 , 70  of HS concrete with a third corrugated sheet  71  sandwiched therebetween. The corrugated sheet  71  is molded in a zigzag pattern, having alternating angular sections  71   a  and short planer sections  71   b  for spacing the planer sheets  70 , 70  apart. The first and second planer sheets  70 , 70  are secured at the third corrugated sheet&#39;s short planer sections  71   b  with an adhesive mortar. The result is a lightweight concrete panel  60  which is strong, without the requirement for reinforcing tensile bar and which is substantially invulnerable to natural degradation. Optionally, the corrugations can be filled with insulation. 
     Opposing linear peripheral edges  72  of each substantially rectangular corrugated panel  60  is fitted with a structural plastic C-shaped extrusion  73 . The C-shaped extrusion  73  has an open side  74  which is oriented outwardly from the panel  60 . The C-shaped extrusion  73  has inward-facing flanges  75  at the open side  74  for constricting the opening and forming a mortise  16 . It is understood that the term mortise  16 , used herein, refers to any peripheral edge connector which has a larger internal dimension that outer dimension, such as a dovetail, thus being capable of retaining a tenon  17 . 
     Having reference to FIG. 12 a  and  12   b,  linear tenons  17  are formed from epoxy resin over a matrix of fiberglass strands (FRP) pultruded through X-shaped dies. As a result, tenons in the form of X-connectors are formed having an X cross-section of 4 symmetrical radially extending wings  19 . As described below, the resultant X-connector tenons  17  are used to connect adjacent and facing mortises of corrugated panels  60 , both to each other and to other building components  15 . 
     In the case of adjacent panels  60 , 60 , when the C-shaped mortises  16  of the peripheral edges  72  of the adjacent panels are placed facing each other, the X-connector tenons  17  can be slid along the facing mortises  16  wherein two wings  19  engage one mortise  16  while the remaining two wings  19  engage the other opposing mortise  16 . Thus, as shown in FIG. 10 c,  the X-connector tenon joins two panels  60 , 60  together. 
     The constricted opening of the C-shaped mortise prevents lateral release of the two engaged wings  19  and prevents separation of the panels  60 . Accordingly, the only permitted displacement of the X-connector tenon  17  is linearly along the mortise  16 . 
     Walls, Floor and Roof Panels 
     The second type of composite panel  61  and  62 , as seen in FIGS. 1 and 9, is constructed of a HS concrete outer sheet  80  and has perpendicular stiffeners or flanges  81  for forming a channel section. An example of use of such a panel  61  is the floor panels  13 . Utilities and the like can be run between the flanges  81 . Mortises  16  are formed at the peripheral edges  72 , both top and bottom, for connection to walls  11  and piles  20  respectively. 
     An insulated panel  62  is used for prefabricated and insulating exterior panels, such as wall  11  and roof panels  14 . A low-density, ultra-low tensile strength, highly-aerated concrete filler  82  (hereinafter referred to as “aerated concrete”) is placed in between the flanges  81  of the channel section. The filler  82  acts as an insulation which also increases the panel&#39;s diagonal rigidity. Again, mortises  16  are formed at the peripheral edges  72 , on each of the two sides, top and bottom, for connection to adjacent walls  11 , crown beam  40  and floor panels  13  respectively. 
     Suspension—Beam and spacers 
     Support beams for the suspension system  12 , best seen in FIG. 1, can be formed using a plurality of corrugated panels  60  such as those used to form the triple-ply beam  31 . 
     Triple-ply strong beams  31  and single ply weaker spacer beams  32 , are supported at the piles  20 . The beams  31 , 32  can be positioned using tongue  24  and groove  25  connectors for positioning on the piles  20  using a mortise  16  and tenon  17  connection. 
     Suspension System—Pilings 
     Two types of supports are provided to accommodate local conditions; particularly to facilitate construction on either a shifting or on a more consolidated base. 
     Referring to FIGS. 1,  1   b,    4   a  and  4   b  a piling  20  is used construction on soft soil. The piling is an FPR pultruded rod with an auger tip  21  on the bottom for screwing into soil, and a square milled top  22 . The beams  31 , 32  of the suspension system  12  are supported on the milled top  22  of the piles  20 . In soft-soil conditions, this type of pile is easily relocatable should the ground shift. 
     In consolidated terrain, a mere pad  23  can be substituted for the piles. 
     Floors 
     Floor panels  13  are secured to the suspension system  12 , as shown in FIGS. 1-1 c,  being anchored to the beams at the outside perimeter of the grid  30 . These panels  13  are formed first with a tongue  24  or groove  25  to mesh with a groove or tongue on the pile&#39;s milled top  22  to act as a locator and secondly with a continuous dovetail mortise  16  in the floor  13  to facilitate joining to a mortise  16  in the pile using the X-connector tenons  17 . The floor panels  13  are amenable to installation of heat transfer tubes and installation of other utilities between their flanges  81 . The panels  13  can be profiled at their ends to match the wall profile, such as if the wall was curved. 
     Exterior Walls 
     Exterior walls  11 , seen in FIGS. 1,  9  and  10   a,  are formed having an exterior concrete shell  80 , a foamed concrete fill  82  and a skreeded interior concrete surface (not detailed). Exterior walls  11  are joined to the floor channels by a series of continuous dovetail mortises in the top of the floor panel  13  which corresponds to dovetail mortises  16  formed on the bottom of the exterior walls  11 . Connections are secured using X-connector tenons  17 . Tongue or grooves on the tops and bottoms of the walls correspond to grooves or tongues respectively on the floor panels  13  and crown beam  40  to act as locators for positioning of walls  11 . 
     Exterior walls  11  are joined to one another side by side using a serpentine tongue joint  85 , as shown in FIG. 13, sealed with a sealant adhesive  86  which prevents air, frost and contaminants from entering the building  10 . 
     Positioning of the walls  11  typically begins at a designated wall corner and continues about the circumference of the floor panels, ending at a recessed setting point pre-molded into selected floor panels  13 . The last wall panel  11 , having a similar setting point moulded into the wall panel&#39;s sides, is levered into position to interlock with the first floor panel  13 , thus providing a completely interlocked exterior finish to the building  10 . 
     Interior Walls 
     Lightweight wall panels, shown in FIGS. 1 and 9, having similar corrugated construction to the panels used for the beams and spacers  31 , 32 , only thinner, are provided for use as interior partitions  50 . The panels  60  are joined together to form partitions  50  as shown in FIG. 10 a  using C-shaped extrusion mortises  16  and X-connector tenons  17 , best seen in FIG. 10 c.  The partitions  50  are removeably secured to the exterior walls  11  utilizing a female socket  90  between the joints of two exterior wall panels  11 , a male elongated strip connector  91  and the C-shaped mortise  16  at the panel  60 . The strip connector  91  has a barb  92 , which fits securely and into the complimentary socket  90 , and two wings  19  of a tenon for fitting with the adjacent panel&#39;s mortise  16 . The partitions  50  are readily connected to the floor panels  13  using conventional hook and loop fasteners  94  (Velcro™) as seen in FIG. 10 d.    
     As shown in FIG. 10 d,  where the partitions  50  are open to the roof  14 , they are capped using an extruded cap  95 . The partitions  50  are also able to support the optional addition of ceilings (not shown). In cases where enhanced circulation is necessary, ceilings are omitted. In cases where ceilings are useful, the same partitions  50  can be used as ceiling material and are constructed to join to the partitions&#39; mortises using suitable right angle connect or tenons. 
     Crown beam and roof construction 
     A crown beam  40 , seen in FIGS. 6 and 7, is formed from HS concrete, having lightening holes  100  along its horizontal axis, to reduce the weight of the beam  40 . It is used similarly as it would be in a conventional construction for roofs built without trussing or rafters. In such cases, it is normally placed vertically with respect to the exterior walls. The addition of a crown beam  40  provides means, at the point of juncture between the wall panels  11  and the roof  14 , to accept the spreading load therefrom. This load would otherwise be dependent upon the walls  11  and could result in wall deviation. 
     Rather than being placed in the conventional vertical position which would result in extra wall height, the crown beam  40  is placed horizontally on top of the walls  11 . Due to its width, the crown beam  40  creates a protuberance on the outside and on the inside of the walls  11 , which further allows it to be used as a building component suitable for the addition of external and internal structural and architectural attachments. 
     As seen in FIG. 7, externally the crown beam  40  is used as an anchor for a concrete rain gutter  41  capable of controlling large volumes of water flow such as might be found in a monsoon. The exposed face of the gutter  41  provides one form of a substitute for the soft and fascia found in conventional construction and minimizes the wind loading, and associated destruction, caused by high winds. 
     As seen in FIG. 7, internally the crown beam  40  is used as a connection for a continuous lighting valance  42 . The lighting valance  42  provides a suitable location for the installation of electrical, plumbing and communication harnesses used to provide services to the building  10 . 
     Installation of the crown beam  40 , between the wall panels  11  below and the roof panels  14  above, provides continuous horizontal strength with overall wall rigidity and relies on special joining conditions to maintain the final wall positioning. The system employs a finger joining technique, as seen in FIG. 8, designed to improve tensile strength in a lateral direction, while maintaining the required horizontal positioning or “bedding” by the casting of the finger joints  44  using a draw-casting method. This method of forming the finger joints  44  results in a downward diminishing taper for locking against movement. 
     The finger joints  44  are further reinforced by the insertion of epoxy fiberglass reinforcing rods  45  which extend axially into the crown beam and vertically through holes formed in the fingers of the finger joints  44 . 
     Roof panels  14  are moulded with overlapping extensions  33  along a bottom and a first vertical side edge. Formed In this fashion, roof panels  14  can be installed by sliding the non-overlapping vertical edge of a panel under the overlapping edge of the previously installed adjacent panel, while at the same time ensuring the bottom edge overlaps panels installed below. Roof panels are connected to one another using X-connectors  17  fitted into the facing dovetail mortises  16  of the adjacent roof panels  14 . The final roof panels  14  must be levered into position as they cannot be slid into position. 
     A peak connector  46  is installed at the apex of the roof  14  to connect the top edges of the opposing roof panels  14  where they meet. The peak connector  46 , shown in FIG. 1, acts to connect and to cap the top of the roof  14 . 
     The overlapping connection of the roof panels  14  provides a continuous, sealed structure relatively impervious to wind and rain. 
     Lighting Valance 
     The continuous lighting valance  42 , as seen in FIGS. 1,  9  and  7 , is connected to the interior edge of the crown beam  40  using an X-connector tenon  17  fit into dovetail mortise  16  on the crown beam  16  and the valance  42 . Reflectors  96  are placed on the adjacent curved roof panel  47  to reflect light from over the valance  42  and into the spaces below. 
     Trays  59  are fitted into the enclosure created by the lighting valance  42  and are joined to dovetail mortise  16  in the top of the crown beam  40  using X-connector tenons as seen in FIG. 1,  9  and  7 . These trays  59  are used to carry all service lines, in harness form, that can be installed or moulded into the walls  11 . This includes electrical, plumbing and communication services. 
     Heating and Cooling System 
     As shown in FIG. 1, a heating and cooling system is provided having a compressed-air, constant-pressure hot air heating system and a series of floor plenums and heat transfer tubes underneath the floor panels  13 . 
     Assembly 
     The panels  13 , 11 , 14  are all assembled and held rigidly together as a unit using corner wall panels  110 , and hip and peak connectors  111 . These connectors  110  and  111  are preferably held together using mortise and tenon connections.