CONCRETE FORM PANEL

Abstract: The present invention discloses a plastic concrete form panel used to construct a concrete structure. The rear surface of the concrete form panel (300) according to the present invention is provided with multiple horizontal and vertical ribs (322, 323), and vertical and horizontal edges (325, 326) for defining a circumference of the panel, wherein the ribs and the edges (325, 326) protruding outwardly from the rear surface (320), respectively. The rear surface (320) is further provided with reinforcing portions (352, 356) along the corners at which the vertical edges (326) and the rear surface (320) meet and along the corners at which the vertical ribs (323) and the rear surface (320) meet, and a gas hole (722, 724) is provided in the reinforcing portions (352, 354). The rear surface (320) is further provided with at least one gas line (342) which is arranged parallel with the horizontal ribs (322) and along the entire horizontal length of the panel, and the gas line (342) communicates with the gas hole (722, 724) in the reinforcing portions (352, 354).

Description: Concrete Form Panel Technical Field The present invention relates to a concrete form panel used to construct a concrete structure and more particularly to a plastic concrete form panel which can maintain the required strength while its shape is not deformed during fabrication even if the thickness of the panel is decreased to thereby lower its weight. Background of the invention It is well known that a concrete structure is constructed by the following procedures: 1) assembling the concrete form panels to define a working space, 2) pouring concrete into the working space, and 3) hardening concrete . Conventionally, the wooden concrete form panels are mainly used, but the wooden panels can not be reused and they require large working load because of their heavy weight. Currently, the concrete form panels fabricated through injection molding of plastics have been developed and utilized. In particular, the GMT (Glassfiber Metreinforced Thermoplastic) type concrete form panels are generally utilized. Fig. 1 show a rear surface of the concrete form panel according to the prior art, which is the GMT type concrete form panel used to construct a concrete structure such as a floor or a ceiling. Referring to Fig. 1, the GMT type concrete form panel for a floor or a ceiling is integrally molded through the GMT injection of general plastics, wherein the front surface (not shown) of the panel 100 is treated substantially smooth and the rear surface 120 of the panel 100 is provided with multiple vertical ribs 122, multiple horizontal ribs 124, and the edge 126 for defining the panel's periphery. The vertical and the horizontal ribs 122 and 124 intersect at 90 ° to each other, and the edge 126 and the ribs 122 and 124 protrude outwardly from the rear surface 120, respectively. Fig. 2 show a rear surface of another concrete form panel according to the prior art, which is the GMT type concrete form panel used to construct a concrete structure such as a wall or a post. Referring to Fig. 2, the GMT type concrete form panel 200 for a wall or a post is also integrally molded through the GMT injection of general plastics, wherein the front surface (not shown) of the panel 200 is treated substantially smooth and the rear surface 220 of the panel 100 is provided with multiple vertical ribs 222, multiple horizontal ribs 224, and the edge 226 for defining the panel's periphery. The vertical and the horizontal ribs 222 and 224 intersect at 90 ° to each other, and the edge 226 and the ribs 222 and 224 protrude outwardly from the rear surface 220, respectively. At the side surface of the panel 200, the recesses 242 for assembling the panels 200 are formed along the edge 226 with predetermined spacing and a reinforced frame 232 is additionally attached to the rear surface 220. The concrete form panel 100 in Fig. 1 need not be connected separately during construction of the concrete structure since the panel 100 is horizontally placed on a frame structure such as a reinforcing rod or a wood frame. However, as being installed upright when constructing a concrete structure, the panels 200 in Fig. 2 must be connected in contact with each other through a separate connecting member (not shown) such that they are not displaced to thereby maintain a desired shape during construction of the concrete structure. The above GMT type concrete form panels 100, 200 may be reused if the connecting members are disconnected after constructing the concrete structure. Thus, the above GMT type concrete form panels 100, 200 are advantageous than the conventional wooden concrete form panel which may not be reused. However, as being fabricated with thickness enough to keep the required strength, the GMT panels 100, 200 become still heavy although the panels 100, 200 are made of plastics . It is possible to decrease the thickness of the GMT panels 100, 200 and thus to lower their weight if the panels 100, 200 are fabricated of plastics having an excellent strength. However, during the molding process of the panel 100, 200 (in particular during a cooling process), the cooling rate of the plastics at the corners at which the rear surfaces 120, 220 and the ribs 122, 124, 222 and 224 meet is different from that at any other portions of the panel 100, 200. Thus, in the case of the thin GMT panels 100, 200, the stress due to such difference in the cooling rate is applied mainly to the corners at which the elongated ribs 122, 222 and the rear surfaces 120, 220 meet, thereby causing the panels 100, 200 to be deformed or distorted. As a result, there exists limit in decreasing the thickness of the GMT panels 100, 200 although the panels 100, 200 are fabricated of plastics having an excellent strength. Further, when constructing the concrete structure such as a wall or a post, the GMT panel 200 becomes heavier since the additional reinforcing frame 232, for example made of steel, is attached to the rear surface 220 of the panel 200, as shown in Fig. 2. Accordingly, in the GMT type concrete form panels 100, 200, a problem still remains that they require large working load due to their heavy weight. Summary of The Invention It is an object of the present invention to provide an improved concrete form panel, wherein the thickness of the panel is decreased while the required strength is satisfied and the deformation is minimized, to thereby decrease the weight of the panel. The foregoing object is accomplished in the present invention by providing a plastic concrete panel comprising a rear surface provided with multiple horizontal and vertical ribs, and vertical and horizontal edges for defining a circumference of the panel, the ribs and the edges protruding outwardly from the rear surface, respectively, characterized in that the rear surface is further provided with reinforcing portions along the corners at which the vertical edges and the rear surface meet and along the corners at which the vertical ribs and the rear surface meet, and a gas hole is provided in the reinforcing portions. The rear surface is further provided with at least one gas line which is arranged parallel with the horizontal ribs and along the entire horizontal length of the panel, and the gas line communicates with the gas hole in the reinforcing portions. The plastic concrete panel according to one embodiment of the present invention has a stepped shape. The plastic concrete panel according to another embodiment of the present invention has a flat shape. Brief Description of the Drawings The present invention will be described in more detail with reference to the accompanying drawings, in which: Fig . 1 is a rear view of a concrete form panel according to the prior art; Fig. 2 is a rear view of another concrete form panel according to the prior art; Fig. 3 is a perspective view of a stepped concrete form panel according to one embodiment of the present invention; Fig. 4 is a sectional view taken along the line I- I of Fig. 1; Fig. 5 is a sectional view taken along the line II-II of Fig. 1; Fig. 6 is a sectional view taken along the line III-III of Fig. 1; Fig. 7A and 7B are enlarged views of the portion A and the portion B of Fig. 6, respectively; Fig. 8 is a perspective view illustrating the interconnection among the concrete form panels of Fig. 1; Fig. 9 is a perspective view of a flat concrete form panel according to another embodiment of the present invention; Fig. 10 is a sectional view taken along the line IV-IV of Fig. 9; Fig. 11A and 11B are enlarged views of the portion C and the portion D of Fig. 10, respectively; Fig. 12 is a sectional view illustrating the interconnection between the concrete form panels of Fig. 9. Detailed Description of The Preferred Embodiments Fig. 3 to Fig. 7B show a stepped concrete form panel according to one embodiment of the present invention, which may be appropriately used to construct the stepped concrete structure. Referring to Fig. 3 thru Fig. 5, the stepped concrete form panel 300 comprises a rear surface 320 provided with multiple ribs 322, 323, 327 and 328, and the vertical and the horizontal edges 325 and 326 for defining the circumference of the panel 300. The ribs 322, 323, 327 and 328, and the edges 325, 326 protrude outwardly from the rear surface 320 to reinforce the strength of the panel 300, respectively. The horizontal ribs 322 are arranged at a predetermined distance between the vertical elongated ribs 323. The horizontal ribs 322 are also arranged at a predetermined distance in the side sections 332 defined by the vertical edges 326 and the opposing vertical ribs 323. The vertical and the horizontal ribs 322, 323 intersect at 90 ° to each other. To further reinforce the strength of the panel 300, the vertical reinforcing ribs 327 are arranged between the vertical ribs 323 and the vertical reinforcing ribs 328 are arranged in the dog-legged portion 338 of the side sections 332. Multiple securing holes 362 for connecting the panels 300 are provided through the sides of the edges 325 and 326. A front surface 310 of the panel 300 is treated substantially smooth. Referring again to Fig. 3, the rear surface 920 is further provided with a main gas line 342 along the whole horizontal length of the panel 300, in particular on a substantially central line of the vertical length of the panel 300, to effectively form reinforcing portions 352 and 356 which will be described later. A gas injecting portion 344 is placed at a substantially central position of the main gas line 342. Referring again to Fig.3 thru Fig.7B, the reinforcing portions 352 are formed at the corners at which the vertical ribs 323 and the rear surface 320 meet, and extend to the corners at which the horizontal edges 325 and the vertical ribs 323 meet. The reinforcing portions 354 are also formed at the inner corners at which the vertical edges 326 and the rear surface 320 meet, and extend to the corners at which the horizontal edges 325 and the vertical edges 326 meet. Gas holes 722 and 724 are provided in the reinforcing portions 352 and 354, respectively and communicate with the gas hole 522 of the main gas line 342. The stepped concrete form panel 300 according to one embodiment of the present invention is fabricated through a gas injection molding method, which will be described schematically. First, melting plastics are injected into a mould (not shown) and then a gas from a gas injector (not shown) is continuously supplied to the gas injecting portion 344 of the main gas line 342 such that, through the gas supplying holes (not shown) , the continuously injected gas is sufficiently supplied to the horizontal edges 325, along the corners at which the vertical elongated ribs 323 and the rear surfaces 320 meet, and along the inner corners at which the horizontal edges 326 and the rear surfaces 320 meet. Then, the reinforcing portions 352 and 354 with the gas holes 722 and 724 therein are formed along the above corners. In fabricating the stepped panel 300 according to the present invention, it is preferable to add material for improving the strength such as rubber, glassfiber and the like into the melting plastics, for example polypropylene, to reinforce the strength of the panel 300. It should be noted that the strength of the stepped panel 300 according to the present invention is improved since the rear surface 320 is further supported by the reinforcing portions 352, 354 in addition to the ribs 322, 323, 327 and 328. Further, even if the vertical elongated ribs 323 are deformed during a cooling process, the stress due to the deformation of the vertical ribs 323 is absorbed by the gas hole 722 and 724 and thus it is possible to block the direct transmission of the stress to the panel 300. Therefore, the stepped panel 300 according to the present invention is prevented from being deformed or distorted. As a result, the concrete form panel 300 according to the present invention can maintain the required strength while its shape is not deformed during fabrication even if the thickness of the panel is decreased to thereby lower its weight. Fig. 8 is a perspective view illustrating the interconnection among the stepped concrete form panels 300 in Fig 3, wherein the concrete form panels 300 are connected in contact with each other by the clip-shaped connecting members 372. Referring to Fig. 8, connecting the panels 300 will be described schematically hereinafter. The panels 300 to be connected are contacted with each other such that the corresponding securing holes 362 communicate each other. Next, one end 372a of the connecting member 372 is inserted into the communicated securing hole 362 of the contacted panels 300 and other end 372b of the connecting member 372 is rotated such that other end 372b elastically clips the contacting edges 325 or 326. Then, the interconnection between the panels 300 is accomplished. According to the above method, it is simple and convenient to connect and/or disconnect the panels 300. Alternatively, the panels 300 may be connected with a bolt and a nut . Fig. 9 to Fig. 11 show a flat concrete form panel according to another embodiment of the present invention, which may be appropriately used to construct the general concrete structure. Referring Fig. 9 to Fig. 11, the flat concrete form panel 900 comprises a rear surface 920 provided with multiple ribs 922 and 923 and the vertical and the horizontal edges 925 and 926 for defining the circumference, which protrude outwardly from the rear surface 920 to reinforce the strength of the panel 900, respectively. The horizontal ribs 922 are arranged at a predetermined distance between the vertical elongated ribs 923. The horizontal ribs 922 are also arranged at a predetermined distance in the side sections 932 defined by the vertical edges 926 and the opposing vertical ribs 923. The vertical and the horizontal ribs 922, 923 intersect at 90 ° to each other. To further reinforce the strength of the panel 900, the vertical reinforcing ribs (not shown) may be arranged between the vertical ribs 923, as in the embodiment of Fig. 3. Multiple securing holes 962 for connecting the panels 900 are provided through the sides of the edges 925 and 926. In addition, at least one boss 972 with a through hole 974 therein is provided between the vertical ribs 923 to assemble the panels 900. Similarly, the stepped panel 300 in Fig. 3 may be provided with at least one boss (not shown) with a through hole to assemble the panels 300. A front surface 910 of the panel 900 is treated substantially smooth. Referring again to Fig. 9, the rear surface 920 is provided with a first gas line 942 and a second gas line 943 which extend from a substantially central position of the horizontal length of the panel 900 to the horizontal edges 926, respectively. It is preferable that the first and the second gas lines 942 and 943 are arranged on the same line, in particular on a substantially central position of the vertical length of the panel 900 to effectively form reinforcing portions 952 and 954 which will be described later. A gas injecting portion 944 and 945 are placed at a substantially central position of the vertical length of the first and the second gas lines 942 and 943. Referring to Fig. 9 thru Fig. 11, the reinforcing portions 952 are formed at the corners at which the vertical ribs 923 and the rear surface 920 meet, and extend to the corners at which the horizontal edges 925 and the vertical ribs 923 meet. The reinforcing portions 954 are also formed at the inner corners at which the vertical edges 926 and the rear surface 920 meet, and extend to the corners at which the horizontal edges 925 and the vertical edges 926 meet. Gas holes 112 and 114 are provided in the reinforcing portions 952 and 954, respectively and communicate with the first gas line 942 or the second gas line 943. Generally, the stress concentrates to the corners of the concrete form panel 900. Accordingly, as shown in Fig. 9, at least one inclined rib 929 is arranged at the upper and the lower portions of the side sections 93210 further reinforce the strength of 4 corners of the panel 900, thereby to prevent the corners from being damaged. Similarly, the stepped concrete form panel 300 may be prevented from being damaged if at least one inclined rib (not shown) is arranged at the upper ad lower portions of the side sections 332. The flat concrete form panel 900 according to another embodiment of the present invention is fabricated through a gas injection molding method, which is the same as in the stepped concrete form panel 300 except using 2 separate gas lines 942, 943 instead of using one gas line 342, and thus the description about the fabricating method of the flat concrete panel 900 will be omitted to avoid duplication. In fabricating the flat panel 900 according to another embodiment of the present invention, it is preferable to add material for improving the strength such as rubber, glassfiber and the like into the melting plastics, for example polypropylene, to reinforce the strength of the panel 900. In the flat concrete panel 900, it should be noted that the strength of the flat panel 900 is improved since the rear surface 920 is supported by the reinforcing portions 952, 954 in addition to the ribs 922, 923 and 929. Further, even if the vertical elongated ribs 923 are deformed during a cooling process, the stress due to the deformation of the vertical ribs 923 is absorbed by the gas holes 112 and 114, and thus it is possible to block the direct transmission of the stress to the panel 900. Therefore, the flat concrete form panel 900 according to another embodiment of the present invention is prevented from being deformed or distorted. As a result, the flat concrete form panel 900 can maintain the required strength while its shape is not deformed during fabrication even if the thickness of the panel is decreased to thereby lower its weight. In fabricating the stepped concrete form panel 300 (or the flat concrete form panel 900) , the gas holes 722 and 724 (or 112 and 114) in the reinforcing portions 352 and 354 (or 952 and 954) may be formed without using the gas line 342 (or 942 and 943) in such a manner that the gas injectors are separately installed at each portion where the gas holes are to be formed. However, the peripheral devices for fabricating the concrete form panel 300 or 900 may be simplified if the gas lines are used as in the above embodiments. In particular, the stepped concrete form panel 300 has a restricted size because a large external force will be applied to the panel during construction of the concrete structure. Accordingly, as shown in Fig. 3, if one main gas line 342 is provided along the whole horizontal length of the concrete form panel 300 at a substantially central position of the vertical length of the panel 300 and the gas injecting portion 344 is provided at a substantially central position of the main gas line 342, the stepped concrete form panel 300 according to the present invention is successfully fabricated although only one gas injector is used. On the other hand, the flat concrete form panel 900 has a relatively large size (typically 600cmX 1200cm in size) because an external force applied to the flat panel 900 is small than that to the stepped panel 300. Accordingly, using only one gas injector makes it difficult to inject a gas smoothly and thereby the gas holes 112 and 114 are frequently not formed in the reinforcing portions 952 and 954. Therefore, it is preferable to fabricate the flat concrete form panel 900 using two gas injectors and two gas lines, as shown in Fig. 9. In addition, a gas line may be divided into three lines and the gas injecting portions may be arranged to each of three lines for a smooth gas injection, when the size of the flat concrete form panel 900 is larger than the predetermined size. The flat concrete form panel 900 in Fig. 9 is connected to each other using the clip-shaped connecting member, similarly to the stepped concrete form panel 300 in Fig. 3. Fig. 12 is a sectional view showing the interconnection between the flat concrete form panels 900 in Fig 9, wherein a pair of panels 900 is connected with their front sides faced each other. Hereinafter, assembling the panels will be described schematically with reference to Fig. 12. First, the panels 900 are vertically arranged and spaced apart such that their front sides 910 are opposite to each other and their through holes 974 are aligned. Then, to obtain a space for pouring and hardening concrete, a guide member 980 such as a hollow pipe is placed between the panels 900 such that the through hole of the guide member 980 and the aligned through holes 974 aligned. A pipe 982 is inserted into the through holes 974 and the aligned through hole of the guide member 980 such that the both ends of the pipe 982 protrude outwardly from the rear surfaces 920 of the panels 900 to be assembled. Then, the anchor bolts 984 are inserted and fixed into the ends of the pipe 982, respectively. The washers 986 and the nuts 988 are then secured to each of the anchor bolts 984. A pair of supporting beams 987 are placed at both sides of the anchor bolts 984 between the ribs 922 and/or 923 and the washer 986, and the nut 988 is screwed with torque such that each of the panels 900 to be assembled is fixed between the guide member 980 and the supporting beam 987. Thereafter, a concrete slurry 990 is poured into the space divided by the assembled panels 900 and hardened to construct the concrete structure. The boss 972 serves not only to guide the pipe 982, but also to protect the panels 900 from the local deformation or damage which may be happened as the panels 900 are assembled. Although not shown in drawings, the stepped concrete form panels 300 in Fig. 3 may be assembled through the same method as in Fig. 12. The invention has been described in terms of preferred embodiments. However, it should be understood that the concrete form panel of this invention is not limited in its application to the specific embodiments and those skilled in the art will recognize that various modifications and variations may be made without departing from the spirit and scope of this invention, as defined in the following claims.

Claims: Claims WHAT IS CLAIMED IS: 1. A plastic concrete form panel comprising a rear surface provided with multiple horizontal and vertical ribs, and vertical and horizontal edges for defining a circumference of said panel, said ribs and said edges protruding outwardly from said rear surface, respectively, characterized in that said rear surface is further provided with reinforcing portions along the corners at which said vertical edges and said rear surface meet and along the corners at which said vertical ribs and said rear surface meet, and a gas hole is provided in said reinforcing portions. 2. The plastic concrete form panel according to claim 1, wherein said rear surface is further provided with at least one gas line which is arranged parallel with said horizontal ribs and along the entire horizontal length of said panel, and said gas line communicates with said gas hole in said reinforcing portions. 3. The plastic concrete form panel according to claim 1 or claim 2, wherein said panel has a stepped shape. 4. The plastic concrete form panel according to claim 3, wherein said horizontal ribs are arranged between said vertical ribs at a predetermined distance, and said horizontal ribs are also arranged at a substantially equal distance in the side sections which are defined by said vertical edges and said opposing vertical ribs, and a main gas line is provided on the substantially central line of the horizontal length of said panel along the entire horizontal length of said rear surface of siad panel, and a gas injecting portion is provided at the substantially central position of said main gas line. 5. The plastic concrete form panel according to claim 4, wherein at least one vertical reinforcing rib is provided between said vertical ribs, and in the dog-legged portion of said side section, respectively. 6. The plastic concrete form panel according to claim 1 or claim 2, wherein said panel is flat. 7. The plastic concrete form panel according to claim 6, wherein said horizontal ribs are arranged between said vertical ribs in a predetermined distance, and said horizontal ribs are also arranged in a substantially equal distance at said side section which is defined by said vertical edges and said vertical ribs, and a first and a second gas lines are provided on the substantially central line of the horizontal length of said panel along the entire horizontal length of said rear surface of said panel, and a gas injecting portion is provided at the substantially central position of said gas lines, respectively. 8. The plastic concrete form panel according to claim 4, wherein an upper and a lower portion of said side section are provided with at least one inclined rib. 9. The plastic concrete form panel according to claim 7 , wherein an upper and a lower portion of said side section are provided with at least one inclined rib. 10. The plastic concrete form panel according to claim 4, wherein at least one boss with a through hole therein is provided at a predetermined position between said vertical ribs. 11. The plastic concrete form panel according to claim 7, wherein at least one boss with a through hole therein is provided at a predetermined position between said vertical ribs. 12. The plastic concrete form panel according to claim 4, wherein multiple securing holes are provided through the sides of said vertical and said horizontal edges . 13. The plastic concrete form panel according to claim 7, wherein multiple securing holes are provided through the sides of said vertical and said horizontal edges .

Inventors: CHOI WUN SUN, CHOI, WUN, SUN
Applicants: CHOI WUN SUN, DAE YEE IND CO LTD, CHOI, WUN, SUN, DAE YEE IND. CO., LTD.
Application year: 1999
Main classification: E04G9
IPC codes: B28B7, E04G9, E04G17