Patent Publication Number: US-10329767-B2

Title: Grid deck with shear-resisting plates

Description:
TECHNICAL FIELD 
     This invention is directed to a grid deck with shear-resisting plates, wherein the shear-resisting plates are pre-cast in the grid deck and partly protrude from the side thereof. 
     BACKGROUND 
     In the construction techniques, a pre-casting method is usually adopted in order to save construction time. In the pre-casting method, the components, such as beams, columns, and decks, are pre-casted off the construction site and are then transported to the construction site for subsequent assembling and grouting. Accordingly, the space at the construction site would be less taken up and support frames used for construction would be greatly reduced. Therefore, the working flow line would be much better. The on-site construction time would be significantly reduced. Since the beams, columns, and decks are produced in the workshop, away from the construction site, the production rate, precision and quality thereof can easily be monitored and reach the expected level. Accordingly, the pre-casting method has become the mainstream for the current construction technology. 
     Grid decks are widely used in the construction of plants, particularly, those for a wafer factory. Grid decks can be produced on-site through grouting or in a pre-casting workshop. The grid decks contain rebar, which reinforces the strength thereof. The grid decks also have hollow portions which effectively reduce the weight thereof. 
     When building a plant, the pre-cast grid decks are laid over the pre-cast columns in a suitable span so that on-site construction is simplified, and thus the construction time is significantly reduced. 
     A normal grid deck assembly is shown in  FIG. 1 . The connecting bars  71 ,  81  protrude from the sides of the grid decks  70 ,  80 , respectively. The connecting bars  71 ,  81  further connect the lap-joint bars  91 . When grid decks are paved, they are laid on the I-beam  60  with gaps therebetween. Grout is filled into the gaps formed between the grid decks  70 ,  80 . After the grout is cured, the grid decks  70 ,  80  will be connected to each other and fixed. 
     The gaps between grid decks  70 ,  80  can be too small so that the overlap length between the lap-joint bars  91  and connecting bar  71  or  81  can be too short and the strength created by the lap joint can be insufficient after the grout is cured. Although the strength can be increased when more connecting bars and lap-joint bars are provided or the width of the gap between the I-beam is used, these two methods will cause an inconvenience to the on-site construction and pre-cast production and make the costs higher. To overcome these problems, an improved method is provided, in which a recess  24 ,  34  is created on each of the grid decks  20 ,  30  to be connected as shown in  FIG. 2 . Connecting bars  21 ,  22 ,  23  and connecting bars  31 ,  32 ,  33  protrude from grid deck  20  and  30 , into the recess  24 , and  34 , respectively. Connecting bars  21 ,  22 ,  23  and connecting bars  31 ,  32 ,  33  are connected by a lap-joint bar  50 . Grout is filled in the gap between the grid decks to be assembled. With the recesses  24 ,  34 , the gap between grid decks  20 ,  30  is wider than that without recesses. The wider gap makes the contact area between the connecting bars, the lap-joint bars and the cement (grout) larger, and thus the strength of connection between the grid decks would be increased. 
     The grid decks with a recess still have the problem of insufficient depth of the recess in some occasions, and when the width of the I-beams is small, there is also a problem of insufficient gap width between the grid decks, which thus causes insufficient connection strength between the grid decks. Accordingly, there is a need to improve the connection of the grid decks. 
     SUMMARY OF INVENTION 
     The objective of the present invention is to overcome the problem of insufficient strength of the connection between grid decks. 
     When grid decks are paved, they are laid on top of the beams. Accordingly, the bottom surface of the grid decks contacts the top surface of the beams. For each beam, each of the two edges of the top surface of the beam contacts one grid deck. Accordingly, the gap between the grid decks is limited by the width of the beam. The insufficient width of the gap will result in insufficient strength of the connection of the grid decks. 
     In the present invention, the grid decks contain shear-resisting plates pre-cast therein. The shear-resisting plates protrude from the sides of a grid deck. When grid decks are laid on the beams, it is the shear-resisting plates that contact the beams. In other words, the grid decks do not directly contact the beams. Accordingly, if two grid decks need a wider gap, appropriate shear-resisting plates can be selected to pre-cast in the grid decks so that the width of the gap between two grid decks will not be limited by the width of the beams and will have a larger width and, moreover, the strength of the connection between grid decks will be increased. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows normal grid decks laid on a beam; 
         FIG. 2  shows a modification of grid decks shown in  FIG. 1 ; 
         FIG. 3  shows the grid decks with shear-resisting plates of the present invention; 
         FIG. 4  shows the grid decks of the present invention which are connected to each other; 
         FIG. 5  shows a partially enlarged view of  FIG. 4 ; and 
         FIG. 6  shows another embodiment of the grid decks with shear-resisting plates. 
     
    
    
     DETAILED DESCRIPTION 
     Conventional grid decks are generally of rectangular shape. Their side surfaces are provided with connecting bars  71 ,  81 , and lap-joint bars  91  (shown in  FIG. 1 ) or connecting bars  21 ,  22 ,  23  and  31 ,  32 ,  33 , and lap-joint bars  50  (shown in  FIG. 2 ). When grid decks  20 ,  30  are interconnected, the connecting bars  21 ,  22 ,  23  and  31 ,  32 ,  33  are connected and grout is filled so that the grid decks  20 ,  30  will be secured to each other. The grid decks  2  of the present invention are shown in  FIG. 3 , where the side surfaces thereof are provided with shear-resisting plates  4 . The shear-resisting plates  4  are pre-cast in a grid deck  2  with a part protruding out of the grid deck  2 . The shear-resisting plate  4  may have a plurality of shear spikes  6 , which will increase the connection strength between them and the grid deck  2 . As shown in  FIGS. 4 and 5 , the positions at which the shear-resisting plates are pre-cast are selected near the corners of the grid deck  2  so that the grid deck has a shear-resisting plate  4  protruding from one side surface at one corner and another shear-resisting plate  4  protruding from the opposite side surface; or a shear-resisting plate  4  protruding from each of two perpendicular side surfaces at each corner ( FIG. 6 ). Referring to  FIG. 3 , the shear-resisting plate  4  protruding from the side surface of the grid deck  2  has a lower edge which is about the same level of the bottom surface of the grid deck. 
     The grid deck  2  with shear-resisting plates  4  can be connected with another grid deck  2  with shear-resisting plates  4  to form a continuous floor. As described above, the connecting bars, lap-joint bars, and shear-resisting plates  4  protruding into the gap between grid decks  2  will securely fix two grid decks after grout is filled into the gap and cured. 
     As shown in  FIGS. 3, 4, and 5 , grid decks  2  are connected above, the top surfaces of the beams  10 . It is similar to conventional grid decks shown in  FIGS. 1 and 2 . The difference is that a conventional grid deck ( FIG. 1 ) is laid on top of the beam  60  and contacts the top surface of the beam, whereas in the present invention, the shear-resisting plates  4  protruding into the gap between two grid decks  2  contact the top surface of the beams  10  with their lower edges ( FIG. 3 ). Accordingly, the grid deck  2  does not directly contact the beam  10 , and the gap between two grid decks  2  is not limited by the width of the beams. Even though the width of the beam is very small, the gap between grid decks can still be maintained in sufficient width if an appropriate size of shear-resisting plates is selected. The sufficient width of gap allows the connecting bars to have a sufficient length to provide high connection strength between grid decks after grout is filled into the gap between the grid decks. If necessary, a gasket  8  (shown in  FIG. 3 ) can be inserted into the position where the shear-resisting plate contacts the beam in order to adjust the level of the grid, deck  2 . 
     From the foregoing, it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without departing from the spirit and scope of the embodiments described herein.