VERTICAL CONSTRUCTION JOINTS FIELD OF INVENTION The present invention relates to a method ofjoining a pre-cast concrete wall panel 5 onto an adjoining column or wall or another pre-cast concrete wall panel without water leakage and to provide a flush surface joint between the pre-cast concrete wall and the adjoining column or wall or another pre-cast concrete wall panel. The invention further relates to a pre-cast concrete wall panel configured for the above method. BACKGROUND OF THE INVENTION 10 Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. There have been numerous methods of interconnecting pre-cast wall panels. One of the methods includes a usage of sealant to interconnect the pre-cast wall panels. However, 15 this method has caused water leakage as the sealant becomes hard after passage of time. In another prior art method of vertical construction joints (as shown in FIGS. 1), formworks are mounted on both sides of the terminal ends of a pre-cast wall panel and in situ concrete is poured into the chamber formed by the formworks and the terminal edge of the pre-cast wall panels. One of the disadvantages of this method is that wet cement slur 20 leaks in between the formworks and the pre-cast concrete wall panels. When the formworks are dismantled, some cement slur is formed on the surface of the pre-cast wall panels and thus, it is necessary to remove the cement slur in order to produce a flush vertical construction joint. This is a labor intensive and laborious task. In another aspect of the prior art method, the pre-cast wall panels are required to be 25 placed adjacent to each other in a respective position. Thus, workers need to join and tighten starter bars of the pre-cast wall panels in a confined area.
2 In another aspect of the prior art method, the pre-cast wall panels are required to be placed adjacent to each other in constructing a vertical construction joint, so that more than one pre-cast wall panels are arranged in accordance to a predetermined arrangement. If a 5 cumulative position overrun from a predetermined arrangement of the pre-cast wall panels occurred or a cumulative position overrun due to either one or more of the pre-cast wall panel were fabricated with bigger dimension than a predetermined design dimension, therefore, a terminal edge of at least one pre-cast wall panel need to be hacked for the pre cast wall panels to be placed in the predetermined position. 10 Therefore, it is an object of the present invention to provide method of constructing vertical construction joints which overcome the problem associated with the prior arts and provide an improvement thereof. SUMMARY OF INVENTION According to a first aspect, the present invention provides a pre-cast wall panel for 15 use in building construction and for connecting to a construction joint or to at least one other pre-cast wall panel or at least one wall by use of formworks, wherein at least one edge portion of the pre-cast wall panel is with a longitudinal recess wherein all leakage of cement slur arising from the casting of in-situ concrete in chamber formed by the edges of the pre-cast wall panels or wall and the formworks is retained within the longitudinal 20 recess. Preferably, the longitudinal recess of the pre-cast wall panel comprises at least one through hole or bore hole for securing at least one formwork to the pre-cast wall panel. According to a second aspect, the present invention provides an L-shaped pre-cast wall panel for use in building construction and for connecting to a joint or to at least one 25 other pre-cast wall panel or at least one wall by use of formworks, wherein an inner surface of an arm of the L-shaped pre-cast wall panel is used to retain all leakage of cement slur 3 arising from the casting of in-situ concrete in chamber formed by the edges of the pre-cast wall panels or wall and the formworks. According to a third aspect, the present invention provides a method for constructing a vertical construction joint by interconnecting at least two pre-cast wall 5 panels through cast in-situ concrete wherein cement slur is retained within a longitudinal recess portion of the pre-cast wall panels. The method comprises the steps of aligning said at least two pre-cast wall panels in a respective position; mounting of at least one formwork bridging between the at least two pre-cast wall panels; pouring in-situ concrete into a chamber enclosed by the edges of the at least two pre-cast wall panels and the at 10 least one formwork; and dismantling of the at least one formwork subsequent upon setting of the in-situ concrete in the chamber, wherein the mounting of the at least one formwork is by overlaying on longitudinal recess of the at least two pre-cast wall panels, and plastering of the vertical construction joint to make the it flush with the adjacent pre-cast wall panels after dismantling the at least one formwork. 15 Preferably, the at least two pre-cast wall panels are aligned at a distance apart from corresponding central grid lines to provide a working space for a worker to tighten at least one bar with vertical bar to form a vertical construction joint, to accommodate cumulative position overrun from predetermined arrangement of pre-cast wall panels, and to accommodate tolerance dimension of pre-cast wall panels. 20 Preferably, the at least two pre-cast wall panels are aligned a spaced apart to form an I-shaped vertical construction joint, a T-shaped vertical construction joint, an L-shaped vertical construction joint or a cross-shaped vertical construction joint. According to a fourth aspect, the present invention provides a method for constructing a vertical construction joint by interconnecting two exterior pre-cast wall 25 panels through cast in-situ concrete wherein cement slur is retained within a longitudinal recess portion of the exterior pre-cast wall panels. The method comprises the steps of aligning two pre-cast exterior wall panels in a respective position; mounting of at least one 4 formwork bridging between the exterior pre-cast wall panels; pouring the cast in-situ concrete into a chamber enclosed by the edges of the two exterior pre-cast wall panels and the at least one formwork; and dismantling of the at least one formwork subsequent upon setting of the in-situ concrete in the chamber, wherein mounting of the at least one 5 formwork at one side of the interconnecting exterior pre-cast wall panels, and wherein the at least one formwork overlays on the longitudinal recess of the two exterior pre-cast wall panels, and plastering of inner surface of the vertical construction joint to make the vertical construction joint flush with the adjacent exterior pre-cast wall panels after dismantling of the at least one formwork. 10 Preferably, the exterior pre-cast wall panels aligned at a distance apart from corresponding central grid lines to provide a working space for a worker to tighten at least one bar with vertical bar to form the vertical construction joint, to accommodate cumulative position overrun from predetermined arrangement ofexterior pre-cast wall panels, and to accommodate tolerance dimension of exterior pre-cast wall panels. 15 According to a fifth aspect, the present invention provides a method for constructing a vertical construction joint by interconnecting two exterior wall panels with a pre-cast wall panel through cast in-situ concrete wherein cement slur is retained within a longitudinal recess portion of the exterior pre-cast wall panels and the pre-cast wall panel, comprising the steps of aligning two exterior pre-cast wall panels with the pre-cast wall 20 panel in a respective position; mounting of at least one formwork bridging between the exterior pre-cast wall panels and the pre-cast wall panel; pouring the in-situ concrete into a chamber enclosed by the edges of the two exterior pre-cast wall panels, the edges of the pre-cast wall panel and the at least one formwork; and dismantling of the at least one formwork subsequent upon setting of the in-situ concrete in the chamber, wherein 25 mounting of the at least one formwork at one side of the interconnecting exterior wall panels, and wherein the at least one formwork overlays on longitudinal recess of the pre cast wall panel and the exterior pre-cast wall panels, and wherein a sealant is applied at another side of the interconnecting exterior pre-cast wall panels, and plastering of inner 5 surface of the vertical construction joint to make it flush with the adjacent exterior pre-cast wall panels and the pre-cast wall panel after dismantling of the at least one formwork. Preferably, the pre-cast wall panel aligned to the exterior pre-cast wall panels at a 5 distance apart from corresponding central grid lines to provide a working space for a worker to tighten at least one bar with vertical bar to form the vertical construction joint, to accommodate cumulative position overrun from the predetermined arrangement of exterior pre-cast wall panels and pre-cast wall panels, and to accommodate tolerance dimension of pre-cast wall panels and exterior pre-cast wall panels. 10 According to a sixth aspect, the present invention provides a method for constructing a vertical construction joint by interconnecting an exterior pre-cast wall panel with an L-shaped pre-cast wall panel through cast in-situ concrete wherein cement slur is retained within a longitudinal recess portion of the exterior pre-cast wall panels and within an adjoining portion of the L-shaped pre-cast wall panel is provided in the present 15 invention. The method comprises the steps of aligning the exterior pre-cast wall panel with the L-shaped pre-cast wall panel in a respective position; mounting of at least one formwork bridging between the exterior pre-cast wall panel and the L-shaped wall panel; pouring the cast in-situ concrete into a chamber enclosed by the edges of the exterior pre cast wall panel, the edges of the L-shaped pre-cast wall panel and the at least one 20 formwork; and dismantling of the at least one formwork subsequent upon setting of the in situ concrete in the chamber; wherein mounting of the at least one formwork at one side of the interconnecting exterior pre-cast wall panel and L-shaped pre-cast wall panel, and wherein the at least one formwork overlays on the longitudinal recess of the exterior pre cast wall panel and an inner surface ofthe L-shaped pre-cast wall panel, and L-shaped pre 25 cast wall panel, and plastering of the vertical construction joint to make it flush with the adjacent exterior pre-cast wall panel and the L-shaped pre-cast wall panel after dismantling of the at least one formwork.
6 Preferably, the exterior pre-cast wall panel and L-shaped pre-cast wall panel aligned at a distance apart to provide a working space for a worker to tighten at least one bar with vertical bar to form the vertical construction joint, to accommodate cumulative position overrun from predetermined arrangement of exterior pre-cast wall panels and L 5 shaped pre-cast wall panel, and to accommodate tolerance dimension ofexterior pre-cast wall panels and L-shaped pre-cast wall panel. Preferably, the thickness of an arm of the L-shaped pre-cast wall panel connected to the exterior pre-cast wall panel is similar to the thickness of the longitudinal recess of the exterior pre-cast wall panel. 10 Advantageously, the present invention minimizes labor intensive and laborious task of producing a vertical construction joint flush with its adjacent pre-cast wall panel. Advantageously, the present invention provides a method of constructing vertical construction joint with a working space for workers to tighten starter bars of pre-cast wall panel. 15 Advantageously, the present invention provides a more flexible arrangement of the pre-cast wall panels. Advantageously, the present invention provides a method of constructing vertical construction joint that eliminates the need of hacking terminal edge of pre-cast wall panel due to cumulative position overrun from a predetermined arrangement of more than one 20 pre-cast wall panel. Therefore, the method in accordance with the present invention is able to accommodate cumulative position overrun from a predetermined arrangement of the pre-cast wall panels. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an 25 inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".
7 BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in greater detail with reference to the accompanying drawings which are given by way of illustration only, and thus, are not limitative of the present invention and wherein: 5 FIG. la is a plan view ofjoin ing two pre-cast concrete wall panels to form a vertical construction joint in accordance with a prior art method; WO 2008/004852 PCT/MY2007/000046 8 FIG. lb is an isometric view of joining two pre-cast concrete wall panels to form a vertical construction joint in accordance with a prior art method; FIG. 2a is an elevation view of a pre-cast concrete wall panel (4); 5 FIG. 2b is a cross sectional view of a pre-cast concrete wall panel (4); FIG. 2c is an isometric view of a pre-cast concrete wall panel (4); 10 FIG. 2d is an enlarged view of an edge portion of a pre-cast concrete wall panel (4); FIG. 3 is an isometric view of an L-shaped exterior pre-cast wall panel (16); FIG. 4a is a plan view of an L-shaped formwork (6); 15 FIG. 4b is a plan view of a straight formwork (7); FIG. 4c is a plan view of a concave L-shaped formwork (8); 20 FIG. 5a is a plan view of two pre-cast concrete wall panels (4a, 4b) placed in a respective position to form a first I-shaped vertical construction joint; FIG. 5b is a plan view of formworks (7a, 7b) mounted against two pre-cast concrete wall panels (4a, 4b) for casting in-situ concrete (12) to form a first I-shaped vertical 25 construction joint; FIG. 5c is a plan view of a first I-shaped vertical construction joint with cement slur (14) retained within longitudinal recesses (1) of the pre-cast concrete wall panels (4a, 4b); WO 2008/004852 PCT/MY2007/000046 9 FIG. 5d is a plan view of a first I-shaped vertical construction joint with plastering to produce a vertical construction joint flush with adjacent pre-cast wall panels (4a, 4b); FIG. 6a is a plan view of three pre-cast concrete wall panels (4c, 4d, 4e) placed in a 5 respective position to form a T-shaped vertical construction joint; FIG. 6b is a plan view of formworks (6a, 6b, 7c) mounted against the pre-cast concrete wall panels (4c, 4d, 4e) for casting in-situ concrete (12) to form a T-shaped vertical construction joint; 10 FIG. 6e is a plan view of T-shaped vertical construction joint with cement slur (14) retained within longitudinal recesses (1) of the pre-cast concrete wall panels (4c, 4d, 4e); FIG. 6d is a plan view of T-shaped vertical construction joint with plastering to produce a 15 vertical construction joint flush with adjacent pre-cast wall panels (4c, 4d, 4e); FIG. 7a is a plan view of four pre-cast concrete wall panels (4f, 4g, 4h, 4i) placed in a respective position to form a cross-shaped vertical construction joint; 20 FIG. 7b is a plan view of formworks (6c, 6d, 6e, 6f) mounted against the pre-cast concrete wall panels (4f, 4g, 4h, 4i) for casting in-situ concrete (12) to form a cross-shaped vertical construction joint; FIG. 7c is a plan view of cross-shaped vertical construction joint with cement slur (14) 25 retained within longitudinal recesses (1) of the pre-cast concrete wall panels (4f, 4g, 4h, 4i); WO 2008/004852 PCT/MY2007/000046 10 FIG. 7d is a plan view of cross-shaped vertical construction joint with plastering to produce a vertical construction joint flush with adjacent pre-cast wall panels (4f, 4g, 4h, 4i); 5 FIG. 8a is a plan view of pre-cast concrete wall panels (4j, 4k) placed in a respective position to form an L-shaped vertical construction joint; FIG. 8b is a plan view of formworks (6h, 8) mounted against the pre-cast concrete wall panels (4j, 4k) for casting in-situ concrete (12) to form an L-shaped vertical construction 10 joint; FIG. 8c is a plan view of L-shaped vertical construction joint with cement slur (14) retained within longitudinal recesses (1) of the pre-cast concrete wall panels (4j, 4k); 15 FIG. 8d is a plan view of L-shaped vertical construction joint with plastering to produce a vertical construction joint flush with adjacent pre-cast wall panels (4j, 4k); FIG. 9a is a plan view of a pre-cast concrete wall panel (4m) placed in a respective position against a wall (17) with starter bars to form a second I-shaped vertical 20 construction joint; FIG. 9b is a plan view of formworks (7d, 7e) mounted against the pre-cast concrete wall panel (4m) for casting in-situ concrete (12) to form a second I-shaped vertical construction joint; 25 FIG. 9c is a plan view of second I-shaped vertical construction joint with cement slur (14) retained within longitudinal recesses (1) of the pre-cast concrete wall panel (4m); WO 2008/004852 PCT/MY2007/000046 11 FIG. 9d is a plan view of second I-shaped vertical construction joint with plastering to produce a vertical construction joint flush with adjacent pre-cast wall panel (4m); FIG. 10a is a plan view of a pre-cast concrete wall panel (4n) and two exterior pre-cast 5 wall panels (18a, 18b) placed in a respective position to form a third I-shaped vertical construction joint; FIG. l0b is a plan view of formworks (6i, 6j) mounted against the pre-cast concrete wall panel (4n) and exterior pre-cast wall panels (18a, 18b) for casting in-situ concrete (12) to 10 form a third I-shaped vertical construction joint; FIG. 10c is a plan view of third I-shaped vertical construction joint with cement slur (14) retained within longitudinal recesses (1) of the pre-cast concrete wall panel (4n) and exterior pre-cast wall panels (18a, 18b); 15 FIG. 10d is a plan view of third I-shaped vertical construction joint with plastering to produce a vertical construction joint flush with adjacent pre-cast wall panel (4n) and exterior pre-cast wall panels (18a, 18b); 20 FIG. 11a is a plan view of an L-shaped exterior pre-cast wall panel (16) and an exterior pre-cast wall panel (18c) placed in a respective position to form a vertical construction joint; FIG. 1ib is a plan view of formwork (7f) mounted against the L-shaped exterior pre-cast 25 wall panel (16) and exterior pre-cast wall panel (18c) for casting in-situ concrete (12) to form a vertical construction joint; WO 2008/004852 PCT/MY2007/000046 12 FIG. 11c is a plan view of a vertical construction joint with cement slur (14) retained within longitudinal recess (1) of the exterior pre-cast wall panel (18c) and within an adjoining portion (19) of the L-shaped pre-cast wall panel (16); 5 FIG. 11d is a plan view of vertical construction joint with plastering to produce a vertical construction joint flush with adjacent exterior pre-cast wall panel (18c); FIG. 12a is a plan view of two exterior pre-cast wall panels (18d, 18e) placed in a respective position to form a vertical construction joint; 10 FIG. 12b is a plan view of formwork (7g) mounted against the exterior pre-cast wall panels (18d, 18e) for casting in-situ concrete (12) to form a vertical construction joint; FIG. 12c is a plan view of a vertical construction joint with cement slur (14) retained 15 within longitudinal recesses (1) of the exterior pre-cast wall panels (18d, 18e); FIG. 12d is a plan view of vertical construction joint with plastering to produce a vertical construction joint flush with adjacent exterior pre-cast wall panels (18d, 18e); and 20 FIGS. 13(a-f) are ground floor plan view, first floor plan view, front elevation view, rear elevation view, left elevation view and right elevation view of a house constructed with vertical construction joints in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS 25 The present invention will be described in detail herein below with reference to preferred embodiments. FIGS. 2(a-d) illustrate a pre-cast wall panel (4) for use in building construction and for connecting to a vertical construction joint or to at least one other pre cast wall panel or a wall by using cast in-situ concrete. In addition, the pre-cast wall panel (4) can be designed as a sandwich pre-cast wall panel to provide thermal insulation and if WO 2008/004852 PCT/MY2007/000046 13 necessary, the pre-cast wall panel (4) can be constructed with one or more openings, window or door openings. The pre-cast wall panel (4) is designed with a longitudinal recess (1) along the edge 5 portion of the pre-cast wall panel (4). The longitudinal recess (1) is located at both front and rear side of the pre-cast wall panel (4). Alternatively, the pre-cast wall panel (4) can be constructed with longitudinal recess (1) on at least one side of the wall panel (4). The longitudinal recess (1) is used to retain cement slur that may arise due to casting of in-situ concrete. 10 Holes (2) are formed at the longitudinal recess (1) during the casting of the pre-cast wall panel (4). The holes (2) are used to insert at least one tie rod (9) for fastening a formwork against the pre-cast wall panel (4) to form a chamber for casting of in-situ concrete (12). Moreover, the holes (2) are either through holes or bore holes. Starter bars 15 (21) are preferably incorporated in the pre-cast wall panel (4). This is to comply with the Code of Practice of Engineering. The pre-cast wall panel (4, 16, 17, 18) described herein below will be referred to a pre-cast wall panel of either an off-form concrete with smooth surface or a smooth surface 20 whereby the pre-cast wall panel is ready for skim coating. An exterior pre-cast wall panel (16) can also be produced in accordance with the present invention whereby at least one longitudinal recess (1) is located at its end portion of inner wall side of the exterior pre-cast wall panel (16). The exterior wall side which 25 forms a facade of a building comprises an extended lip at its end portions. FIG. 3 illustrates an isometric view of an L-shaped exterior pre-cast wall panel (16). One side of the L-shaped exterior pre-cast wall panel (16) forms a facade of a building whereas another side of the L-shaped exterior pre-cast wall panel (16) forms an WO 2008/004852 PCT/MY2007/000046 14 inner wall of the building. The L-shaped exterior pre-cast wall panel (16) comprises of two arms wherein one arm is an adjoining portion whereas another arm is designed with at least one longitudinal recess (1). This adjoining portion (19) is used to connect to an exterior wall panel. The inner wall surface of the adjoining portion (19) is used to retain cement 5 slur that may arise due to casting of in-situ concrete. The exterior wall surface of the L shaped exterior pre-cast wall panel (16) consists of an extended lip at its end portions. Holes (2) are formed at the longitudinal recess (1) during the casting of the L shaped exterior pre-cast wall panel (16). The holes (2) are used to insert at least one tie rod 10 (9) for fastening a formwork against the L-shaped exterior pre-cast wall panel (16) to form a chamber for casting of in-situ concrete (12). Moreover, the holes (2) are either through holes or bore holes. Starter bars (21) are preferably incorporated in the L-shaped exterior pre-cast wall panel (16). This is to comply with the Code of Practice of Engineering. 15 The L-shaped exterior pre-cast wall panel (16) has a smooth surface whereby the pre-cast wall panel (16) needs only skim coating without any plastering. Moreover, it is appreciated that the L-shaped pre-cast wall panel (16) can be constructed as a sandwiched pre-cast wall panel. Although, in FIGS. 3, the L-shaped exterior pre-cast wall panel (16) is illustrated without any opening area, it is appreciated that the L-shaped pre-cast wall panel 20 (16) can be constructed with door, window, ventilation or any other opening. Formwork is used to contain the in-situ concrete during the pouring and setting of the in-situ concrete. The formwork is built out of prefabricated modules. The formwork consists of a wanted surface structure with a frame. The wanted surface structure is the 25 contact surface between the concrete and the formwork lies. The frame reinforces the structure in place during pouring and setting of the in-situ concrete. Preferably, the frame is made of timber and the wanted surface structure is made of plywood. However, it is appreciated that the formwork can be constructed either of steel plate, plastic or fiber glass.
WO 2008/004852 PCT/MY2007/000046 15 FIG. 4a is an L-shaped formwork (6). The formwork (6) consists of a wanted surface structure (60) moulded in an L-shape with a frame (61) that reinforces L-shaped surface structure (60) in place against a pre-cast wall panel or a wall during pouring and setting of the in-situ concrete. FIG. 4b is a straight formwork (7). The formwork (7) 5 consists of a straight or I-shaped wanted surface structure (70) with a frame (71) to reinforce the surface structure (70) in place during pouring and setting of the in-situ concrete. FIG. 4c is a plan view of a formwork (8). The formwork (8) consists of a concave L-shaped wanted surface structure (80) with a frame (81) to reinforce the surface structure (80) in place against a pre-cast wall panel or a wall during pouring and setting of 10 the in-situ concrete. Although described herein below that the formworks are either of straight-shaped (7), L-shaped (6) or concave L-shaped (8), the formwork can also be constructed of any other shape in order to cast the wanted shape of the vertical construction joint. 15 FIGS. 5(a-d) show a method of constructing a first I-shaped vertical construction joint by connecting two pre-cast concrete wall panels (4a, 4b). Referring to FIG. 5a, two pre-cast concrete wall panels (4a, 4b) are placed in a respective position whereby the terminal edges of the two pre-cast wall panels (4a, 4b) are facing each other. The pre-cast wall panels (4a, 4b) are positioned at a distance apart from corresponding central grid lines 20 to provide a working space for at least one worker to tighten the starter bars (21) with vertical bar in the first I-shaped vertical construction joint and to accommodate cumulative position overrun from the predetermined arrangement of more than one pre-cast wall panel (4) and to accommodate for tolerance dimension of pre-cast wall panel (4). 25 Referring now to FIG. 5b, two formworks (7a, 7b) are mounted against the pre cast wall panels (4a, 4b). The formworks (7a, 7b) are mounted bridging between the two pre-cast wall panels (4a, 4b) wherein its end portions are placed against the longitudinal recesses (1) at the front side of the pre-cast wall panels (4a, 4b).
WO 2008/004852 PCT/MY2007/000046 16 The formworks (7a, 7b) are held in place by at least one tie rod (9) and at least a pair of tie nuts (10). The tie rod (9) is inserted through the hole (2) of the pre-cast wall panels (4a, 4b) for fastening of the formworks (7a, 7b) in position. Preferably, timber pads (11) are placed in between the tie nuts (10) and pre-cast wall panels (4a, 4b) to stabilize the 5 tie nuts (10) and the formworks (7a, 7b). Thereon, in-situ concrete (12) is poured into a chamber enclosed by the edges of the pre-cast wall panels (4a, 4b) and the wanted surface structure of the formwork (7a, 7b) to form the vertical construction joint. 10 During pouring of the in-situ concrete (12), some cement slur (14) may come out through the gap in between the formworks (7a, 7b) and the pre-cast wall panels (4a, 4b). However, this cement slur (14) is retained within the longitudinal recesses (1) of the pre cast wall panels (4a, 4b) as shown in FIG. 5c. 15 In FIG. 5d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent pre-cast concrete wall panels (4a, 4b). FIGS. 6(a-d) show a method of constructing a T-shaped vertical construction joint. 20 Referring now to FIG. 6a, three wall panels (4c, 4d, 4e) are aligned and placed in a respective position to form a T-Shaped vertical construction joint. The pre-cast wall panels (4c, 4d, 4e) are positioned at a distance apart from corresponding central grid lines to provide working space for at least one worker to tighten starter bars (21) with vertical bar in the T-shaped vertical construction joint and to accommodate cumulative position 25 overrun from predetermined arrangement of more than one pre-cast wall panel (4) and to accommodate for tolerance dimension of pre-cast wall panel (4). Referring now to FIG. 6b, three formworks (6a, 6b, 7c) are mounted against the pre-cast wall panels (4c, 4d, 4e). A first formwork (7c) is a straight formwork. The first WO 2008/004852 PCT/MY2007/000046 17 formwork (7c) bridges between the first pre-cast wall panel (4c) and second pre-cast wall panel (4d) with its end portions overlaying the longitudinal recesses (1) at the front side of the first pre-cast wall panel (4c) and second pre-cast wall panel (4d). A second formwork (6a) is an L-shaped formwork with its end portions overlaying the longitudinal recesses (1) 5 at the rear side of the first pre-cast wall panel (4c) and the third pre-cast wall panel (4e). A third formwork (6b) is an L-shaped formwork overlaying the longitudinal recess (1) at the rear side of the second pre-cast wall panel (4d) and the longitudinal recess (1) at the front side of the third pre-cast wall panel (4e). 10 Each formwork (6a, 6b, 7c) is held in place by at least one tie rod (9) and at least a pair of tie nuts (10). The tie rod (9) is inserted through the hole (2) of the pre-cast wall panels (4c, 4d, 4e) for fastening of the formworks (6a, 6b, 7c) in position. Timber pads (11) are placed in between the tie nuts (10) and pre-cast wall panels (4c, 4d, 4e) to stabilize the tie nuts (10) and the formwork (6a, 6b, 7c). 15 Thereon, in-situ concrete (12) is poured into a chamber enclosed by the terminal edges of the pre-cast wall panels (4c, 4d, 4e) and the wanted surfaces of the formworks (6a, 6b, 7c) to form the T-shaped vertical construction joint. 20 Some cement slur (14) may come out through the gap in between the formworks (6a, 6b, 7c) and the pre-cast wall panels (4c, 4d, 4e) during pouring of the in-situ concrete (12). However, the cement slur (14) is retained within the longitudinal recesses (1) of the pre-cast wall panels (4c, 4d, 4e) as shown in FIG. 6c. 25 In FIG. 6d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent pre-cast concrete wall panels (4c, 4d, 4e). FIGS. 7(a-d) illustrate a method of constructing a cross-shaped vertical construction joint. Referring to FIG. 7a, four wall panels (4f, 4g, 4h, 4i) are aligned and WO 2008/004852 PCT/MY2007/000046 18 placed in a respective position to form a cross-shaped vertical construction joint. The pre cast wall panels (4f, 4g, 4h, 4i) are positioned at a distance apart from corresponding central grid lines to provide a working space for at least one worker to tighten starter bars (21) with vertical bar in the cross-shaped vertical construction joint and to accommodate 5 cumulative position overrun from predetermined arrangement of more than. one pre-cast wall panel (4) and to accommodate for tolerance dimension of pre-cast wall panel (4). Referring now to FIG. 7b, four formworks (6c, 6d, 6e, 6f) are mounted against the pre-cast wall panels (4f, 4g, 4h, 4i). The formworks (6c, 6d, 6e, 6f) are L-shaped 10 formworks. A first formwork (6c) bridges between a first pre-cast wall panel (4) and a second pre-cast wall panel (4g) with its end portions overlaying the longitudinal recesses (1) of the front side of the first pre-cast wall panel (4f) and the second pre-cast wall panel (4g). A second formwork (6d) bridges between the second pre-cast wall panel (4g) and a third pre-cast wall panel (4h) with its end portion overlaying the longitudinal recesses (1) 15 at the rear side of the second pre-cast wall panel (4g) and at the front side of the third pre cast wall panel (4h). A third formwork (6e) bridges between the third pre-cast wall panel (4h) and a fourth pre-cast wall panel (4i) with its end portion overlaying the longitudinal recesses (1) at the rear side of the third pre-cast wall panel (4h) and at the front side of the fourth pre-cast wall panel (4i). A fourth formwork (6f) bridges between the fourth pre-cast 20 wall panel (4i) and the first pre-cast wall panel (4f) with its end portion overlaying the longitudinal recesses (1) at the rear side of the first pre-cast wall panel (4f) and the fourth pre-cast wall panel (4i). Each formwork (6c, 6d, 6e, 6f) is held in place by at least one tie rod (9) and at 25 least a pair of tie nuts (10). The tie rod (9) is inserted through the hole (2) of the pre-cast wall panels (4f, 4g, 4h, 4i) for fastening the formworks (6c, 6d, 6e, 6f) in place. Timber pads (11) are placed in between the tie nuts (10) and pre-cast wall panels (4f, 4g, 4h, 4i) to stabilize the tie nuts (10) and the formworks (6c, 6d, 6e, 6f).
WO 2008/004852 PCT/MY2007/000046 19 Thereon, the in-situ concrete (12) is poured into a chamber enclosed by the edges of the pre-cast wall panels (4f, 4g, 4h, 4i) and the wanted surface structure of the formworks (6c, 6d, 6e, 6f) to form the cross-shaped vertical construction joint. 5 Referring to FIG. 7c, during pouring of the in-situ concrete (12), some cement slur (14) may come out through the gap in between the formworks (6c, 6d, 6e, 6f) and the pre cast wall panels (4f, 4g, 4h, 4i). However, the cement slur (14) is retained within the longitudinal recesses (1) of the pre-cast wall panels (4f, 4g, 4h, 4i). 10 Thereon, in FIG. 7d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent pre-cast concrete wall panels (4f, 4g, 4h, 4i). FIGS. 8(a-d) show a method of constructing an L-shaped vertical construction joint. Referring to FIG. 8a, two pre-cast wall panels (4j, 4k) are aligned and placed in a 15 respective position to form an L-shaped vertical construction joint. The pre-cast wall panels (4j, 4k) are positioned at a distance apart from corresponding central grid lines to provide a working space for at least one worker to tighten starter bars (21) with vertical bar in the L-shaped vertical construction and to accommodate cumulative position overrun from predetermined arrangement of more than one pre-cast wall panel (4) and to 20 accommodate for tolerance dimension of pre-cast wall panel (4). Referring now to FIG. 8b, two formworks (6h, 8) are mounted against the pre-cast wall panels (4j, 4k). A first formwork (8) is a concave L-shaped formwork wherein its end portions overlays the longitudinal recesses (1) at the front side of the pre-cast wall panels 25 (4j, 4k). A second formwork (6h) is an L-shaped formwork with its end portions overlays on the longitudinal recesses (1) at the rear side of the pre-cast wall panels (4j, 4k). Thus, the end portions of the wanted surface structure of the formworks (6h, 8) overlay on the longitudinal recesses (1).
WO 2008/004852 PCT/MY2007/000046 20 Each formwork (6h, 8) is held in place by at least one tie rod (9) and at least a pair of tie nuts (10). The tie rod (9) is inserted through the hole (2) of the pre-cast wall panels (4j, 4k) for fastening of the formiworks (6h, 8) in position. Timber pads (11) are placed in between the tie nuts (10) and pre-cast wall panels (4j, 4k) to stabilize the tie nuts (10) and 5 the formworks (6h, 8). Thereon, the in-situ concrete (12) is poured into a chamber enclosed by the edges of the pre-cast wall panels (4j, 4k) and the wanted structures of the formworks (6h, 8) to form the vertical construction joint. 10 During pouring of the in-situ concrete (12), some cement slur (14) may come out through the gap in between the formworks (6h, 8) and the pre-cast wall panels (4j, 4k). However, the cement slur (14) is retained within the longitudinal recesses (1) of the pre cast wall panels (4j, 4k) as shown in FIG. 8c. 15 In FIG. 8d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent pre-cast concrete wall panels (4j, 4k). Referring now to FIG. 9a, a pre-cast wall panel (4m) is placed and aligned in 20 perpendicular relationship to a wall (17) in a respective position in order to form a second I-shaped vertical construction joint. The pre-cast wall panel (4m) is positioned at a distance apart from corresponding central grid lines to provide a working space for at least one worker to tighten starter bars (21) with vertical bar in the second I-shaped vertical construction joint and to accommodate cumulative position overrun from predetermined 25 arrangement of more than one pre-cast wall panel (4) and to accommodate for tolerance dimension of pre-cast wall panel (4). Referring to FIG. 9b, two formworks (7d, 7e) are mounted against the pre-cast wall panel (4m) and the wall (17), wherein one end portion of a first formwork (7d) WO 2008/004852 PCT/MY2007/000046 21 overlays the longitudinal recesses (1) at the front side of the pre-cast wall panel (4m) whereas another end portion of the first formwork (7d) is contiguous to the surface of the wall (17). A second formwork (7e) is mounted in similar manner as the first formwork (7d) at the rear side of the pre-cast wall panel (4m). 5 Each formwork (7d, 7e) is held in place by at least one tie rod (9) and at least a pair of tie nuts (10). The tie rod (9) is inserted through the hole (2) of the pre-cast wall panel (4m) for fastening of the formworks (7d, 7e) in position. Timber pads (15) are placed in between the tie nuts (10) and pre-cast wall panel (4m) to stabilize the tie nuts and the 10 formworks (7d, 7e). Thereon, the in-situ concrete (12) is poured into a chamber enclosed by the edges of the pre-cast wall panel (4m), surface of the wall (17) and the wanted surface structures of the formworks (7d, 7e) to form the vertical construction joint. 15 During pouring of the in-situ concrete (12), some cement slur (14) may come out through the gap in between the formworks (7d, 7e) and the pre-cast wall panel (4m). However, the cement slur (14) is retained within the longitudinal recess (1) of the pre-cast wall panel (4m) as shown in FIG. 9c. 20 In FIG. 9d, cement sand plasters (13) are used to make the vertical construction joint (12) flush with the adjacent pre-cast concrete wall panel (4m). Referring now to FIG. 10a, a pre-cast wall panel (4n) is aligned in perpendicular 25 relationship to two exterior pre-cast wall panels (18a, 18b) in a respective position in order to form a third I-shaped vertical construction joint. The pre-cast wall panel (4n) is positioned at a distance apart from corresponding central grid line to provide a working space for at least one worker to tighten starter bars (21) with vertical bar in the third I shaped vertical construction joint and to accommodate cumulative position overrun of WO 2008/004852 PCT/MY2007/000046 22 predetermined arrangement of more than one pre-cast wall panel (4), and exterior pre-cast wall panel (18), and to accommodate for tolerance dimension of pre-cast wall panel (4) and exterior pre-cast wall panel (18). 5 In FIG. 10b, two L-shaped formworks (6i, 6j) are mounted against the pre-cast wall panel (4n) and the exterior wall panels (18a, 18b). The formworks (6i, 6j) used are L shaped formworks. A first formwork (6i) overlays on the longitudinal recesses (1) at the front side of the pre-cast wall panel (4n) and the rear side of a first exterior pre-cast wall panel (18a). A second formwork (6j) overlays on the longitudinal recesses (1) at the front 10 side of the pre-cast wall panel (4n) and the rear side of a second exterior pre-cast wall panel (18b). Each formwork (6i, 6j) is held in place by at least one tie rod (9) and at least a pair of tie nuts (10). The tie rod (9) is inserted through the hole (2) of the pre-cast wall panel 15 (4n) for fastening the formworks (6i, 6j) in position. Timber pads (15) are placed in between the tie nuts (10) and pre-cast wall panels (4n) to stabilize the tie nuts (10) and the formworks (6i, 6j). For the front side of the exterior pre-cast wall panels (18a, 18b) which is the facade 20 of the building, a sponge rod with sealant (20) is applied to prevent the in-situ concrete (12) from slurring onto the facade of the building. Thereon, the in-situ concrete (12) is poured into a chamber formed by the edges of the pre-cast wall panels (4n), the edges of the exterior pre-cast wall panels (18a, 18b) and 25 the wanted surface structures of the formworks (6i, 6j) to form the vertical construction joint. Some cement slur (14) may come out through the gap in between the formworks (6i, 6j) and the pre-cast wall panel (4n) and in between the formworks (6i, 6j) and the WO 2008/004852 PCT/MY2007/000046 23 exterior pre-cast wall panels (18a, 18b) during pouring of the in-situ concrete (12). However, the cement slur (14) is retained within the longitudinal recesses (1) of the pre cast wall panel (4n) and the exterior pre-cast wall panels (18a, 18b) as shown in FIG. 10c. 5 Thereon, in FIG. 10d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent pre-cast concrete wall panel (4n) and the exterior pre-cast wall panels (18a, 18b). Referring now to FIG. 11a, an exterior pre-cast wall panel (18c) is aligned to an L 10 shaped exterior pre-cast wall panel (16) in a respective position in order to form a vertical construction joint wherein thickness of an adjoining portion (19) of the L-shaped exterior pre-cast wall panel (16) is similar to the thickness of the longitudinal recess (1) of the exterior pre-cast wall panel (18c). The exterior pre-cast wall panel (18c) and the L-shaped exterior pre-cast wall panel (16) are positioned at a distance apart from corresponding 15 central grid lines to provide a working space for at least one worker to tighten starter bars (21) with vertical bar in the vertical construction joint, and to accommodate cumulative position overrun from predetermined arrangement of more than one exterior pre-cast wall panel (18) and L-shaped exterior pre-cast wall panel (16), and to accommodate for tolerance dimension of exterior pre-cast wall panel (18) and L-shaped exterior pre-cast 20 wall panel (16). In FIG. lb, a formwork (7f) is mounted against the exterior pre-cast wall panel (18c) and the L-shaped pre-cast wall panel (16). One end portion of the formwork (7f) overlays on the longitudinal recess (1) of the exterior pre-cast wall panel (18c) whereas 25 another end portion of the formwork (7f) overlays on inner wall surface of the adjoining portion (19) of the L-shaped exterior pre-cast wall panel (16). The formwork (7f) is held in place by at least one pair of tie nuts (10), at least one pair of drop-in anchors (8) and at least one tie rods (9). The drop-in anchors (8) are inserted WO 2008/004852 PCT/MY2007/000046 24 into the exterior pre-cast wall panel (18c) and the L-shaped exterior pre-cast wall panel (16). Thereon, at least one tie rod (9) is inserted through the drop-in anchors (8) for fastening the formwork (7f) in position. Timber pads (11) are placed in between the tie rods (9) and the exterior pre-cast wall panels (16, 18c) to stabilize the tie nuts (10) and the 5 formwork (7f). For the front side of the exterior pre-cast wall panels (16, 18c) which is the facade of the building, a sponge rod with sealant (20) is applied to prevent the in-situ concrete (12) from slurring into the facade of the building. 10 Thereon, the in-situ concrete (12) is poured into a chamber formed by the edges of the exterior pre-cast wall panel (18c), the edges of the L-shaped exterior pre-cast wall panel (16) and the wanted surface structures of the formwork (7f) to form the vertical construction joint. 15 Some cement slur (14) may come out through the gap in between the formworks (7f) and the exterior pre-cast wall panels (16, 18c) during pouring of the in-situ concrete (12). However, the cement slur (14) is retained within the longitudinal recesses (1) of the exterior pre-cast wall panel (18c) and the L-shaped exterior pre-cast wall panel (16) as 20 shown in FIG. 11c. Thereon, in FIG. 11d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent exterior pre-cast wall panel (18c) and the L shaped exterior pre-cast wall panels (16). 25 Referring to FIGS. 12a, two exterior wall panels (18d, 18e) are aligned in a respective position in order to form a vertical construction joint. The exterior pre-cast wall panels (18d, 18e) are positioned at a distance apart from corresponding central grid lines to provide a working space for at least one worker to tighten starter bars (21) with vertical bar WO 2008/004852 PCT/MY2007/000046 25 in the vertical construction joint, and to accommodate cumulative position overrun from the arrangement of more than one exterior pre-cast wall panel (18), and to accommodate for tolerance dimension of exterior pre-cast wall panel (18). 5 Referring now to FIG. 12b, a formwork (7g) is mounted against the exterior pre cast wall panels (18d, 18e) wherein its end portions overlays on the longitudinal recesses (1) of the exterior pre-cast wall panels (18d, 18e). The formwork (7g) is held in place by at least one pair of tie nuts (10), at least one 10 pair of drop-in anchors (8) and at least one tie rods (9). The drop-in anchors (8) are inserted into the exterior pre-cast wall panels (18d, 18e). Thereon, the tie rod (9) is inserted into the drop-in anchors (8) for fastening the formwork (7g) in position. Timber pads (11) are placed in between the tie rods (9) and the exterior pre-cast wall panels (18d, 18e) to stabilize the tie nuts (10) and the formwork (7g). 15 For the front side of the exterior pre-cast wall panels (18d, 18e) which is the facade of the building, a sponge rod with sealant (20) is applied to prevent the in-situ concrete (12) from slurring into the facade of the building. 20 Thereon, the in-situ concrete (12) is poured into a chamber formed by the edges of the exterior pre-cast wall panels (18d, 18e) and the wanted surface structures of the formwork (7g) to form the vertical construction joint. Some cement slur (14) may come out through the gap in between the formworks 25 (7g) and the exterior pre-cast wall panels (18d, 18e) during the pouring of the in-situ concrete (12). However, the cement slur (14) is retained within the longitudinal recesses (1) of the exterior pre-cast wall panels (18d, 18e) as shown in FIG. 12c. Thereon, in FIG. 12d, cement sand plasters (13) are used to make the vertical construction joint flush with the adjacent exterior pre-cast wall panels (18d, 18e).
WO 2008/004852 PCT/MY2007/000046 26 FIGS. 13(a-f) illustrate a house constructed in accordance with the present invention. The vertical construction joints of the house are constructed in accordance with the aforementioned methods and by using the pre-cast wall panel in accordance with the present invention. Numeral 30 denotes the first I-shaped vertical construction joint, 5 numeral 31 denotes the T-shaped vertical construction joint, numeral 32 denotes the cross shaped vertical construction joint, numeral 33 denotes the L-shaped vertical construction joint and numeral 34 denotes the second I-shaped vertical construction. Although in the preferred embodiments, the longitudinal recess (1) is a projected 10 portion extended along its longitudinal axis, it is appreciated that the longitudinal recess (1) can be a plurality of predetermined interval ribs along its longitudinal axis in order to retain all leakages of cement slur (14) arising from the casting of in-situ concrete (12) in a chamber formed by the edges of the pre-cast wall panels or wall and the formworks. Moreover, in the preferred embodiments, the tie nuts (10) and tie rods (9) are used to lock 15 and secure the formwork to the pre-cast wall panel, however, it is appreciated that any fastening means can be used to lock and secure the formwork to the pre-cast wall panel. Moreover, in the preferred embodiments, cement sand plaster (13) is used to produce a vertical construction joint flush with its adjacent pre-cast wall panels or exterior pre-cast wall panels, however, it is appreciated that the cement sand plaster can be substituted with 20 any other material in order to prevent hairline crack and to produce the vertical construction joint flush with its adjacent pre-cast wall panels or exterior pre-cast wall panels. While embodiments of the invention have been illustrated and described, it is not 25 intended that these embodiments illustrated and describe all possible forms of the invention. Rather, the words used in the specifications are words of description rather than limitation and various changes may be made without departing from the spirit and scope of the invention.