IMPROVEMENTS TO FORMWORK PANEL AND ACCESSORY

FIELD OF INVENTION

The present invention generally relates to improvements of formwork panel for forming concrete structure, and more particularly to a modular plastic formwork panel and its construction support accessory for construction of walls, floor, ceiling, beams, slabs and/or pillars in concrete.

BACKGROUND OF INVENTION Concrete forming apparatus is widely use in construction of buildings, bridges, and other concrete structures. A common system for forming concrete structures uses a plurality of modular form components that are adapted to be assembled into a wide variety of configurations to conform virtually any architectural requirement. Such forming apparatus components are typically made of metal so that they are adequately strong to support pressure from poured concrete and durable so that the components can be reused many times.

Wall/Column i) Metal Formworks One of the most common used configurations of such metal form components is a flat panel that is used in forming substantially flat concrete surfaces, such as walls, foundations, column, and the like (e.g. US Pat. No. 5, 833, 873 and US App. No. 2002/0158184). Such metal concrete form panels have a face sheet which is in contact with the poured concrete. A rearwardly extended flange is secured around the perimeter of the face sheet. Pluralities of spaced apart support members or stiffeners may be tied to the perimeter flange, and tie rods or similar components are used to tie the flanges to flanges of the wall panel on the opposite side of the wall being formed. Since the face sheet spans rib to rib, the welded support members or stiffeners induce compression stress in the face sheets, particularly when force is exerted against the face sheet by the concrete. If the compression force is large enough, the face sheet will deflect between the ribs and the finished concrete will have a pillowed appearance. Walers, external stiffeners and the like may be attached to the back side

of the forming panel in an effort to reduce the compression forces induced on the face panel and thereby reduce the likelihood that it will deflect. The use of the support members and stiffeners however are time consuming. Further, they add to the weight of the forms and so require stronger, more expensive equipment to move around the construction site and make the forms more difficult to maneuver into place by workers. Moreover, cured concrete tends to adhere to the metal form panel leaving unfavorable surface finishing to the wall. Further surface cleaning and maintenance to the metal form panel are required. Concrete form release agent may be applied to metal form face sheet to form a release film for effectively prevents the bonding of the concrete to the formwork, so that to assist in clean, quick, form release and removal. However, surface cleaning and preparation to remove rust, scale and/or previously used form release agents from the metal form panel are cumbersome. It requires substantial time and operation cost for the cleaning and preparation.

ii) Plywood/PIastic-PIy/Composite-PIy Panels with Metal Frames

Another conventional concrete form is composed of a frame having two pairs of parallel outer steel rails, one pair of rails being perpendicular to the other pair of rails so as to form a rectangular frame. The frame may have a number of parallel inner rails which are connected to the outer-rails to form a number of rectangular bays within the frame. A concrete-forming plate, which may be for example, plywood, plastic-ply or composite-ply securely attached to the frame. Such conventional concrete forms are typically positioned adjacent to each other, and sometimes on top of each other, to form cavities of various shapes and sizes where wet concrete is poured. When positioned, the concrete forms are securely fastened by connecting means securely engaged to holes or slots formed at outer rails of concrete forms, so that pressure from poured wet concrete does not alter the position of the concrete forms. Stiffeners or back supports may be provided at outer side of the plywood, plastic-ply or composite-ply panel for further strengthening the structure. Elongate beams or walers may also be provided to extend horizontally along the outer side of each panel. An outwardly opening pocket formed as part of the waler retains nailed to which plywood, plastic-ply or composite-ply panel can be nailed,

screwed or otherwise fastened to the waler. When concrete cured, the panels are removed and to be reused. Similarly, cured concrete tends to adhere to the plywood, plastic-ply, or composite-ply panel leaving unfavorable surface finishing to the wall. Concrete form release agent may also be applied to the plywood, plastic-ply, or composite-ply face sheet to form a release film for effectively prevents the bonding of the concrete to the formwork. However, surface cleaning and preparation to remove scale and/or previously used panels are cumbersome, thus requiring substantial time and operation cost for the cleaning and preparation.

iii) Plastic/Fiber reinforced Formworks

Concrete formworks are also know which, being made of plastics material, such as, for example, thermo-formed polymers or fiber-reinforced plastics, particularly resolve the disadvantages of modular structures made of metal, wood or composite (e.g. U.S. Pat. No. 6, 117, 521 and U.S. Pat. No. 5, 632, 923). However, the formworks still involve a high degree of complexity in putting them to use, since they require number of accessories for the attachment of adjoining elements to withstand the force or pressure exerted by the poured concrete. Thus, it involves complex operation and requires substantially high level of skill in assembling the formwork. Further, in order to obtained plastic formworks with sufficient resistance to deformation, it is necessary to produce retaining panels of suitable thickness and/or a very high number of ribs both at the edges and in a transversal position. Designs of the panel are relatively complex, thus involved substantially high production cost and high level of operation skill. In addition, prior art plastic formwork unable to solve pillowing effect on the face sheet. Side edge deformation still appears as a result of the force or pressure exerted by the poured concrete. Furthermore, cured concrete still adhere to the plastic form panel and leaving unfavorable surface finishing to the wall. Secondary process such as surface cleaning and maintenance to the plastic form panel are still required. The concrete form release agent may also need to apply to the plastic form face sheet to form a release film for effectively prevents the bonding of the concrete to the formwork panel. The secondary process however is cumbersome and it requires substantial time and

operation cost for cleaning and preparation. Hence, recycling period for re-used is high.

Slab/Beam Concrete slab or beam is a common structural element usually constructed in modern building. The concrete slab or beam may be prefabricated or constructed in situ. In situ slab/beam is usually built with formworks into which wet concrete is poured. Accordingly, the formworks may be formed of wooden planks, plastic boards, steel plates or those prior art mentioned above incorporation with connecting members. The connecting member may be nailed, screwed or wedged to the formwork so that cavity of desired size or shape of slab or beam is formed. If the slab or beam is to be reinforced, re-bars are positioned within the formwork before concrete is poured.

There have been many suggestions of connecting member such as angle bar or bracket used in either temporary or permanent form with the formwork for constructing the concrete slab or beam (e.g. U.S. Pat. No. 6, 119, 429 and U.S. Pat. No. 3, All, 982). The connecting member can be temporary in placed and then to be removed after concrete is cure, or it can be contained in concrete as permanent part. Some other prior art includes fastening means where it can be secured and connected to outer periphery of the formworks. However, said fastening means need to be nailed or screwed into formworks to form a cavity of desire shape of slab or beam. One known metal connector for example, an "L" bracket which includes holes through one of its flange for rigid connection with nails or screws onto the formwork board. Other flange includes slot allowing other formwork board to be flexibly connected with nails or screws. The used of nails or screws to join the formworks are relatively weak especially when larger concrete slabs or beams are to be constructed. The nails and screws tend to be bent or crushed at spanned gap when the formwork is stress with sudden impact. Aesthetically, the use of nails or screws leaving a poor surface finish on the concrete slab or beam, and it may need additional process to enhance aesthetic appeal on surface finishing.

Object of Present Invention

It is a principle object of the present invention, therefore to provide improved modular plastic formwork panel and its construction support accessory for construction of walls, beams, slabs and/or pillars in concrete. The present invention provides an improved modular plastic formwork panel and its construction support accessory, that is simple, light-weight, high reliability and strong enough to withstand the pressure caused by expansion of setting concrete, of poured concrete, or other forces, and reduce pillowing of the formwork. A new, re-usable modular plastic formwork with improved ribs and groove has been developed to resist pillowing on face sheet and deflection on side edges without substantial additional weight and manufacturing cost. Moreover, the modular plastic formwork panel is non-adhesive or non-stick to concrete. It provides a favorable/smooth surface finish to the wall when concrete is cured. No further secondary processes, such as surface cleaning and maintenance are required to the formwork panel. Therefore, it eliminates the use of release agent to the formwork panel and thus, reduces operation cost as well as maintenance cost.

The present invention also provides a construction support accessory enables the formworks serve for casting in place and it can be quickly put in place prior to pour of wet concrete. The construction support accessory can be quickly removed in re-usable condition after concrete is cure. The construction support accessory also provides a rigid, firm connection in communication with the formwork. Moreover, the construction support accessory eliminating cumbersome nailing or screwing works during and/or after the construction. In addition, the improved modular plastic formwork panel and its construction support accessory provide high quality surface finish, and thus eliminating the need to enhance aesthetic appeal on surface finishing, or require any release agent for surface clean-up.

SUMMARY OF INVENTION Accordingly, a formwork panel for the construction of walls, floors, ceilings, beams, slab and/or pillars comprising an inner smooth surface and an outer surface comprises plurality of ribs, said formwork panel having predetermined spaced apart

apertures along its perimeter to receive connecting means, characterized in that the formwork panel comprises a) a reinforced rib integrally disposed within waffle box formed by the plurality of ribs, said reinforced rib includes a reinforced ring with radially extending stiffeners integrally protruded from the outer surface of the formwork panel; and b) a reinforced groove is provided along perimeter of the formwork panel defining a first side edge and a second side edge; wherein the first side edge is tapered into predefined angle to form a tapered portion there along the perimeter of the formwork panel. Said tapered portion enables to provide a "spring effect" between two adjacent facing first side edges at contact portion. The reinforced groove and the tapered portion allow tight fitting between two or more formwork panels when the connecting means is introduced. The "spring effect" of the tapered portion further tightens the contact portion of two adjacent formwork panels when concrete is being poured. The inner smooth surface of the formwork panel is non- adhesive or non-stick to concrete.

The non-adhesive or non-stick to concrete feature of the formwork panel can be achieved by introducing Polyethylene (PE) and/or Polypropylene (PP), mixed with composite materials in the process of making the formwork panel. Preferably, the formwork panel is produced by injection molding. The composite materials may include, for example, coupling and foaming agents serve to improve impact strength of the formwork panel; plasticizers and surface active agent serve as anti-bonding element for non-adhesive or non-stick feature. UV stabilizers may also be included to prevent aging of the formwork panel.

The formwork panel is provided with predetermined cut-off lines for cutting into desired smaller sections or is in a standard predetermined size without any cutoff lines. The cut-offline is a predefined groove formed along the longitudinal and/or lateral direction of the formwork panel. The predefined groove is serving as a guide for a cutting device to cut the formwork panel into desire rectangular shape or size.

The reinforced ring enables desired tie hole to be made to receive a tie rod and resistance to surface elongation caused by repeatable usage of the tie rod. The

radially extending stiffeners further provide resistance to deflection and pillowing of the formwork panel caused by heavy loading, sudden impact or dropping object.

The predetermined spaced apart apertures include an integrally reinforced loop disposed along the reinforced groove and are of size adapted to receive the connecting means. The reinforced groove allows self-draining of wet concrete penetrated into still existing gap between the reinforced grooves of two adjacent formwork panels. The wet concrete is draining out through the reinforced groove (22) and the predetermined spaced apart apertures.

A construction support accessory incorporates with formwork panels for the construction of walls, floors, ceilings, beams, slab and/or pillars characterized in that the construction support accessory includes i) a first plate portion and second plate portion joined at junction line X to form a substantially L-shaped member; and ii) a plurality of predetermined spaced apart recesses extending outwardly along bottom edge of the second plate portion defining a hook portion to receive the formwork panel. The formwork panel is plastic formwork panel or combinations of wooden, plywood, composite or metal form.

The hook portion is optionally provided with a protruded lip integrally extended upwardly from the predetermined spaced apart recesses. The first plate portion and second plate portion are preferably joined at angle, θ approximately in a range of 80 ° < θ < 90°. Distal ends of the second plate portion are provided with a cut-off edge trimmed at approximately angle of 45 ° for corner joint. The first plate portion is substantially plane at its inner surface and is optionally provided with protruded plug-in pin. The plug-in pins is spaced apart disposed along the inner surface of the first plate portion.

BRIEF DESCRIPTION OF DRAWINGS The drawings constitute a part of this specification and include an exemplary or preferred embodiment of the invention, which may be embodied in various forms.

It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.

In the appended drawings: FIG. 1 is a perspective view illustrating outer surface of a standard formwork panel having plurality of ribs in accordance with preferred embodiment of the present invention.

FIG. 2a is a perspective view illustrating outer surface of another formwork panel with plurality of ribs that can be cut into smaller section or required size. FIG. 2b is a cross-sectional perspective view taken along line A - A of FIG. 2a.

FIG. 2c is a partly enlarged view of the FIG. 2b illustrating cut-off lines of the formwork panel.

FIG. 3a is a perspective view illustrating inner smooth surface of two formwork panels in different sizes. FIG. 3b is a partly enlarged perspective view of FIG. 3a illustrating contact portion of two adjacent formwork panels.

FIG.3c is a front view of FIG.3b.

FIG. 3d is an enlarged view of the contact portion of two adjacent formwork panels when connecting means is introduced. FIG. 4 is a partially enlarged perspective view of FIG. 2a illustrating reinforced ribs and connecting means.

FIG. 5 illustrates another type of connecting means for connecting two or more formwork panels.

FIG. 6a shows the formwork panels incorporate with construction support accessory for construction of concrete slab.

FIG. 6b is a perspective view of FIG. 6a without the concrete poured.

FIG.7a is a perspective view of the construction support accessory.

FIG. 7b is a side view illustrating first embodiment of the construction support accessory. FIG. 7c is a side view illustrating second embodiment of the construction support accessory.

FIGS. 8a and 8b are partially enlarged front view of FIG. 6a illustrating the connection of the formwork panel and the second embodiment of the construction support accessory.

FIG. 9a shows the combination of wooden and plastic formwork panels incorporate with the construction support accessory for constructing the concrete slab.

FIGS. 9b and 9c are partially enlarged front view of FIG. 9a illustrating the connection of the formwork panel and the first embodiment of the construction support accessory.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A detailed description of preferred embodiments of the invention is disclosed herein. It should be understood, however, the disclosed preferred embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not interpreted as limiting, but merely as the basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the preferred embodiments of present invention in virtually any appropriate detailed structure.

Referring to FIG. 1, there is shown generally a standard formwork panel (10) formed in accordance with preferred embodiment of the present invention.

Preferably, the standard formwork panel (10) is formed in a standard size of, but not limited to 0.6m x 1.2m. Said standard formwork panel (10) may be varying in size depending on requirement or on area of use. Preferably, the standard formwork panel

(10) may be made of plastics material, for example Polyethylene (PE) and/or Polypropylene (PP), mixed with composite materials.

Referring now to FIGS. 2a - 2c, there is shown another type of formwork panel (30) formed in accordance with another preferred embodiment of the present invention. Said formwork panel (30) is substantially similar to the standard formwork panel (10). However, the formwork panel (30) is formed in a size of 0.6m x 1.2m, but includes additional aspect where it can be cut into smaller sections as required. Accordingly, said formwork panel (30) includes additional cut-off lines (40) whereby

it can be easily cut into smaller sections or required sizes depending on architectural requirement or on the area of use. The cut-offline (40) may be a predefined groove (41) formed along the longitudinal and/or lateral direction of the formwork panel (30). The groove (41) may serve as a guide for a cutting device to cut the formwork panel (30) into desire rectangular shape or size.

For example, the standard size of 0.6m x 1.2m formwork panel (30) can be cut into two pieces of 0.3m x 1.2m section, or it can be cut into sixteen pieces of 0.3m x 0.15m section. Any other sizes may also be cut as required, as the formwork panel (30) can be cut into smallest size up to 0.05m x 0.05m. Preferably, the formwork panel (30) may also be made of plastics material such as Polyethylene (PE) and/or Polypropylene (PP), mixed with composite materials.

It is important to note that the formwork panel (10, 30) is non-adhesive or non-stick to concrete. Particularly, inner smooth surface (12) of the formwork panel

(10, 30) is non-adhesive to the concrete. It provides a favorable/smooth surface finish to the wall when concrete is cured. As a result, no further secondary processes, such as surface cleaning and maintenance are required to the formwork panel. It eliminates the use of release agent to the formwork panel and thus, reduces operation cost as well as maintenance cost.

The non-adhesive or non-stick to concrete feature of the formwork panel can be achieved by introducing Polyethylene (PE) and/or Polypropylene (PP), mixed with composite materials in the process of making the formwork panel. Preferably, the formwork panel is produced by injection molding. The composite materials may include, for example, coupling and foaming agents serve to improve impact strength of the formwork panel; plasticizers and surface active agent serve as anti-bonding element for non-adhesive or non-stick to concrete feature. UV stabilizers may also be included to prevent aging of the formwork panel.

Referring to FIGS. 3a - 3d, 4 and 5, the formwork panel (10, 30) generally comprises a face sheet having an inner smooth surface (12) and outer surface (14).

The inner smooth surface (12) has no ribs and it is an internal surface of the formwork panel in contact with the concrete. The outer surface (14) is provided with plurality of ribs (16) integrally formed on the outer surface (14) of the face sheet (FIGS. 1 & 2). The plurality of ribs (16) includes cross-linked longitudinal ribs (16a) and lateral ribs (16b) into which substantially waffle boxes is formed. Reinforced ribs (18) may be provided on the outer surface (14) of the face sheet (FIG. 4). Accordingly, the reinforced rib (18) is an integrally projected portion formed on the outer surface (14) of the face sheet and it is disposed within the waffle box formed by the plurality of ribs (16). Particularly, the reinforced rib (18) includes a substantially reinforced ring (18a) with radially extending stiffeners (18b) integrally protruded from the outer surface (14) of the face sheet, so that its further increase reinforcement to the face sheet of the formwork panel subjected to heavy loading such as pored concrete, or sudden impact such as hammering, or dropping object such as steel bars. The reinforced ring (18a) enables desired tie hole to be made within the reinforced ring (18a) to receive a tie rod. Said reinforced ring (18a) enables the face sheet to serve longer as the formwork panel is tend to be re-use for many times. Accordingly, the reinforced ring (18a) enables desired tie hole to be made to receive a tie rod and to resist surface elongation caused by repeatable usage of the tie rod. Moreover, radially extending stiffeners (18b) of the reinforced rib (18) further increased resistance to deflection or pillowing of the formwork panel when used to contain and form concrete.

The outer surface (14) where waffle boxes are formed by plurality of ribs (16) is surrounded by a frame (20). The frame (20) is generally formed by longitudinal edge (20a) and lateral edge (20b). Said longitudinal edge (20a) and lateral edge (20b) are provided with reinforced groove (22) along the perimeter of the formwork panel (10, 30). As can be clearly seen in FIGS. 3b and 3c, the reinforced groove (22) is formed on the frame (20) defining a first side edge (22a) and second side edge (22b) along the perimeter of the formwork panel. Said first side edge (22a) is tapered into predefined angle to form a tapered portion (24) along the perimeter of the formwork panel. A plurality of predetermined spaced apart apertures (26) is provided on the reinforced groove (22). Accordingly, said predetermined spaced apart

apertures (26) are equally formed along the perimeter of the formwork panel. Preferably, the predetermined spaced apart aperture (26) includes an integrally formed reinforced loop (26a) to further reinforce the opening of the aperture. Said predetermined spaced apart apertures (26) are of size adapted to receive a connecting means or a construction support accessory.

By way of example and not by way of limitation, the connecting means may be of, for example, a general type of pin and wedge fastener (50) incorporated with the predetermined spaced apart aperture (26) to connect two or more formwork panels (FIG. 4). Said pin and wedge fastener (50) is known in the art and will not be described herein in details. The connecting means may also be of, for example, a metal or plastic form clamping device (60), for fixing two or more formwork panels at their mutually frame sides (FIG.5). Such connecting means is commonly used and is also known as "P-clamp" designed by Economy Forms Corporation, Des Moines, Iowa, U.S. Pat. No. 2, 102, 717. Said connecting means will not be described further as it is known in the cited prior art.

The inventor founds that when two or more conventional formwork panels are used by arranging them side by side in series, a gap is formed in a contact portion between one formwork and another formwork panel when the connecting means is introduced. The gap becomes more appearance when the wet concrete is being poured due to the weight. The poured concrete slurry may be penetrated into the gap formed in the contact portion. As a result, scales solidifies and adheres to side portions, i.e. the contact portions of the formworks is required, and maintenance work for the removal of the scales is required for re-using the formwork panels.

The reinforced groove (22) and the tapered portion (24) of the present invention enable to solve the above mentioned problem and have excellent performances which cannot be achieved by conventional wooden, metal or plastic formworks. Said reinforced groove (22) and the tapered portion (24) of the present invention enable to prevent the occurrence of gap when the formwork panels are connected by the connecting means (FIG. 3d). Accordingly, when the formwork

panels of the present invention are side by side connected by the connecting means, the two facing reinforced grooves (22) will be clamped by the connecting means and being forced to substantially in contact to each other. As a result, the tapered portion (24) of two facing first side edges (22a) along perimeter of the formwork panel will be substantially distorted and firmly be connected. Thus, the occurrence of gap between two formworks is minimized or eliminated in the contact portion of two adjacent formwork panels. Even if there is the gab still exists in the contact portion, the reinforced groove (22) and the tapered portion (24) allow self-draining of poured wet concrete that penetrated into the gap between the reinforced grooves (22) of two adjacent panels. It will be appreciated that although the formwork panels will be slightly bend upward due to "spring effect" of the tapered portion (24) of two facing first side edges (22a); the formworks panels will become flatten when the concrete is being poured. Thus, the "spring effect" of the tapered portion (24) further tightens the contact portion of two adjacent formwork panels. The reinforced groove (22) and the tapered portion (24) enable to prevent any deflection on side edges of the formwork, particularly, the longitudinal edge (20a) and lateral edge (20b) of the frame (20).

By way of example and not by way of limitation, FIGS. 6a - b, 7a - c, 8a - b and 9a - c illustrate the use of the formwork panel (10, 30) incorporating with construction support accessory (70) for construction of concrete slab, beam or the like. The construction support accessory (70) generally formed of one-piece unitary member. Said construction support accessory (70) is preferably made of, but not limited to a plastics material formed by injection molding. For example, the plastics material may be a Polyethylene (PE) and/or Polypropylene (PP), mixed with composite materials. Alternatively, the construction support accessory (70) can also made of, but not limiting to bending die stamped sheet metal with predetermined thickness, or it can be made of metal plate members joint by welding. Said construction support accessory (70) can also be made of aluminum or other light weight metal depending on demand or application used. It will be appreciated that selection of materials should be light weight, stiff and resist to any atmospheric or environmental conditions.

Reffering now to FIGS. 7a - c, the construction support accessory (70) generally comprises a first plate portion (72) and a second plate portion (74) joined at junction line X to form a substantially L-shaped member. It will be appreciated that the construction support accessory (70) may be varying in other forms depending on application use for connecting the formwork panels in relative to construction of slab or beam. Preferably, the first plate portion (72) and the second plate portion (74) are joined at angle, θ approximately in a range of 80 ° < θ < 90°. The angle, θ between the joint of first plate portion (72) and the second plate portion (74) of the construction support accessory (70) enables the formwork panel to be released easily when the concrete slab/beam is set.

The second plate portion (74) is provided with a plurality of predetermined spaced apart recesses (78) extending outwardly along bottom edge of the second plate portion (74) defining a hook portion to receive the formwork panel. The hook portion is optionally provided with a protruded lip (80) intervally extended upwardly from the predetermined spaced apart recesses (78). Preferably, distal ends of the second plate portion (74) are provided with a cut-off edge (76) trimmed at approximately angle of 45 ° for corner joint.

According to the first embodiment of the construction support accessory (70), the first plate portion (72) of the construction support accessory (70) is substantially plane at its inner surface (73). Said inner surface (73) of the first plate portion (72) enables the construction support accessory (70) to be rest seated on and in direct contact with the frame of the formwork panel configured in upright position. The formwork panel may be a plastic formed panel as described above or it may be a plywood panel depending on the size of the slab/beam to be constructed or on the application use.

In accordance with second embodiment of the construction support accessory (70), the first plate portion (72) may be optionally provided with protruded plug-in pin (72a). The plug-in pins (72a) may be spaced apart disposed along the inner surface (73) of the first plate portion (72). Particularly, the plug-in pins (72a) are of

configuration in matingly engage with the predetermined spaced apart apertures (26) disposed along the perimeter of the formwork panel (10, 30).

In construction of the concrete slab or beam, the preferred embodiments of the construction support accessories (70) are usually used incorporating with the formwork panels (10, 30) or in combination with the plywood formwork (90).

For example, as can be seen in FIGS. 6a - b, a cavity of desired size and shape of slab/beam is formed by plurality of formwork panels (10, 30) incorporate with the second embodiment of the construction support accessory (70). The first plate portion (72) of second preferred embodiment having plug-in pins (72a), which are spaced apart disposed along its inner surface (73), enables to be configured on the frame of substantially upright formwork panel (30). Particularly, the plug-in pins (72a) of the second preferred embodiment are of configuration in matingly engage with the predetermined spaced apart apertures (26) disposed along the perimeter of the formwork panel (10, 30) (FIGS. 8a - b). Other formwork, for example, formwork panel (10) may be rest seated on or engageble with the predetermined spaced apart recesses (78) of the second plate portion (74) and supported by supporting beams. Accordingly, for horizontal formwork panels, they will be supported by supporting beams, generally known as "P-beam" for example, shown as arrows illustrated in FIGS. 6a - b. The protruded lip (80) which intervally extended upwardly from the predetermined spaced apart recesses (78) is enable to engage with the waffle box formed by the plurality of ribs (16) of the formwork panel (10), and it prevents the formwork panel (10) from slideably movement either in longitudinal or lateral directions. If the slab/beam is to be reinforced, re-bars may be positioned within the formworks before concrete is poured. The angle, θ between the joint of first plate portion (72) and the second plate portion (74) of the construction support accessory (70) enables the formwork panel (10) to be released easily when the concrete slab/beam is set (FIG. 8b).

In another example, a cavity of desired size and shape of slab/beam may be formed by plurality of formwork panels (10, 30) or in combination with the plywood

formwork (90) (FIGS. 9a - c). In this case, first embodiment of the construction support accessory (70) may be used. The first plate portion (72) of the first preferred embodiment enables to be configured and rest seated on the frame of substantially upright plywood formwork (90). Other formwork, for example, formwork panel (10) may be rest seated on or engageble on the predetermined spaced apart recesses (78) of the second plate portion (74) and supported by the supporting beams. Similarly, for horizontal formwork panels, either the formwork panels (10, 30) or plywood formworks, they will be supported by supporting beams, generally known as "P- beam" for example, shown as arrows illustrated in FIG. 9a. The protruded lip (80) which intervally extended upwardly from the predetermined spaced apart recesses (78) is enable to engage with the waffle box formed by the plurality of ribs (16) of the formwork panel (10), and it prevents the formwork panel (10) from slideably movement either in longitudinal or lateral directions. If the slab/beam is to be reinforced, re-bars may be positioned within the formworks before concrete is poured. The angle, θ between the joint of first plate portion (72) and the second plate portion (74) of the construction support accessory (70) enables the formwork panel (10) to be released easily when the concrete slab/beam is set (FIG. 9b).

The present invention provides an improved modular plastic formwork panel and its construction support accessory, which is simple in design, light-weight, and they can be easily installed without expensive skilled workers or special tools. The improved formwork panel is strong enough to withstand the pressure caused by expansion of setting concrete, poured concrete or other forces, and it also reduce pillowing of the formwork. Accordingly, the improved formwork panel with improved ribs and grooves enables to resist pillowing on the face sheet and deflection on side edges without substantial additional weight and manufacturing cost. The improved formwork panel is reusable. Moreover, the modular plastic formwork panel

(10, 30) is non-adhesive or non-stick to concrete. It provides a favorable/smooth surface finish to the wall when concrete is cured. No further secondary processes, such as surface cleaning and maintenance are required to the formwork panel.

Therefore, it eliminates the use of release agent to the formwork panel and thus, reduces operation cost as well as maintenance cost.

Furthermore, the construction support accessory of the present invention enables formworks serve for casting in place and it can be quickly put in place prior to pour of wet concrete. The construction support accessory can be quickly and easily removed in re-usable condition after concrete is cure. The construction support accessory also provides a rigid, firm connection in communication with the formwork. Moreover, said construction support accessory eliminating cumbersome nailing or screwing works during and/or after the construction. In addition, the improved modular plastic formwork panel and its construction support accessory provide high quality surface finish, and thus eliminating need to enhance aesthetic appeal on surface finishing, or require any release agent for surface clean-up.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the principle and scope of the invention, and all such modifications as would obvious to one skilled in the art intended to be included within the scope of following claims.