Load supporting structure

Abstract

A load supporting structure such as a bridge deck is mounted on two spaced beams and includes a pre-cast concrete panel with a plurality of transverse tension straps attached to the edges of the panel by anchoring studs attached to the tension member and embedded within the panel such the tension straps—prevent spreading of the panel so that loads are transferred from an upper surface of the panel to the beams by forming a compressive arch within the panel. A concrete deck slab is cast over the pre-cast panel and is attached to the tension straps by embedded anchor studs located on the straps outside the panel so as to form a compressive arch within the slab. The compressive arch loading avoids the use of tension reinforcing steel in the concrete which can corrode. The use of a pre-cast panel and cast slab simplifies assembly as no welding to the beams on site is required.

1 . A load supporting structure comprising: 
 a plurality of laterally spaced apart beams including two which define a space therebetween;    each beam having a support surface extending along an upper surface of the beam; and    a concrete deck mounted on and spanning the space between the beams, the deck comprising:    a pre-cast concrete panel having two opposed outer edge portions supported on the respective support surfaces;    a plurality of tension members at positions spaced apart longitudinally of the panel each extending across the concrete panel at or adjacent a lower surface thereof;    each tension member having adjacent respective ends thereof at least one panel anchoring member attached to the tension member and embedded within the panel at the outer edge portions thereof such the tension members prevent spreading of the panel so that loads are transferred from an upper surface of the panel to the beams by forming a compressive arch within the panel;    and a cast in place concrete deck slab covering the pre-cast panel;    and each tension member having adjacent respective ends thereof at least one slab anchoring member attached to the tension member and embedded within the deck slab at the outer edge portions thereof such the tension members prevent spreading of the slab on the panel so that loads are transferred from an upper surface of the slab to the beams by forming a compressive arch within the slab.    
   
   
       2 . A load supporting structure according to  claim 1  wherein each of the slab anchoring members and the panel anchoring members comprises an upstanding shear transfer stud with a bottom end fastened to the respective tension member.  
   
   
       3 . A load supporting structure according to  claim 2  wherein each shear stud has a shaft and an upper head of greater transverse dimension than the shaft.  
   
   
       4 . A load supporting structure according to  claim 1  wherein the tension member extends to a position beyond an outer edge of the panel and wherein the at least one slab anchoring member is located on the tension member at the position beyond the outer edge of the panel.  
   
   
       5 . A load supporting structure according to  claim 1  wherein the compressive arch in the panel and in the slab avoids the requirement for transversely extending tension reinforcement in the panel and in the slab.  
   
   
       6 . A load supporting structure according to  claim 1  herein a lower surface of the concrete panel is recessed at a center area between the outer edge portions such that tension member is exterior to the panel at the center area.  
   
   
       7 . A load supporting structure according to  claim 1  wherein each of the beams has on its support surface a support pad extending longitudinally along the beam and defining the support surface.  
   
   
       8 . A load supporting structure according to  claim 7  wherein each pad is formed from an elastomeric material.  
   
   
       9 . A load supporting structure according to  claim 1  wherein the tension member is free from fixed connection directly to the beam.  
   
   
       10 . A load supporting structure according to  claim 1  wherein the beam has slab anchoring members thereon for connection of the slab to the beam for communication of forces from the compressive arch in the slab to the beam.  
   
   
       11 . A load supporting structure according to  claim 1  wherein the concrete of the slab and the panel contains staple fibers for micro-crack reinforcement.  
   
   
       12 . A method of forming a load supporting structure comprising: 
 providing a plurality of laterally spaced apart beams including two which define a space therebetween;    each beam having a support surface extending along an upper surface of the beam; and    providing a pre-cast concrete panel having a body of concrete with a center area and two opposed outer edge portions shaped and arranged such that a transverse width spans the beams and such that a longitudinal length extends along the beams;    providing in the pre-cast panel a plurality of tension members at positions spaced apart longitudinally of the panel each extending across the concrete panel at or adjacent a lower surface thereof;    each tension member having adjacent respective ends thereof at least one panel anchoring member attached to the tension member and embedded within the panel at the outer edge portions thereof;    applying the pre-cast panel so as to span the beams with the edge portions resting on the support surface of the beam such the tension members prevent spreading of the panel so that loads are transferred from an upper surface of the panel to the beams by forming a compressive arch within the panel;    and each tension member having adjacent respective ends thereof at least one slab anchoring member attached to the tension member and exposed from the panel;    cast in place onto the panel a concrete deck slab so as to cover the pre-cast panel;    and embedding the slab anchoring members within the deck slab at outer edge portions thereof such the tension members prevent spreading of the slab on the panel so that loads are transferred from an upper surface of the slab to the beams by forming a compressive arch within the slab.    
   
   
       13 . The method according to  claim 12  wherein each of the slab anchoring members and the panel anchoring members comprises an upstanding shear transfer stud with a bottom end fastened to the respective tension member.  
   
   
       14 . The method according to  claim 13  wherein each shear stud has a shaft and an upper head of greater transverse dimension than the shaft.  
   
   
       15 . The method according to  claim 12  wherein the tension member extends to a position beyond an outer edge of the panel and wherein the at least one slab anchoring member is located on the tension member at the position beyond the outer edge of the panel.  
   
   
       16 . The method according to  claim 12  wherein the compressive arch in the panel and in the slab avoids the requirement for transversely extending tension reinforcement in the panel and in the slab.  
   
   
       17 . The method according to  claim 12  wherein a lower surface of the concrete panel is recessed at a center area between the outer edge portions such that tension member is exterior to the panel at the center area.  
   
   
       18 . The method according to  claim 12  wherein each of the beams has on its support surface a support pad extending longitudinally along the beam and defining the support surface.  
   
   
       19 . The method according to  claim 12  wherein each pad is formed from an elastomeric material.  
   
   
       20 . The method according to  claim 12  wherein the tension member is free from fixed connection directly to the beam.  
   
   
       21 . The method according to  claim 12  wherein the beam has slab anchoring members thereon for connection of the slab to the beam for communication of forces from the compressive arch in the slab to the beam.  
   
   
       22 . The method according to  claim 12  wherein the concrete of the slab and the panel contains staple fibers for micro-crack reinforcement.  
   
   
       23 . A pre-cast concrete panel for mounting on laterally spaced apart beams defining a space therebetween comprising: 
 a body of concrete with a center area and two opposed outer edge portions shaped and arranged such that a transverse width spans the beams and such that a longitudinal length extends along the beams;    a plurality of tension members in the pre-cast panel at positions spaced apart longitudinally of the panel each extending across the concrete panel at or adjacent a lower surface thereof;    each tension member having adjacent respective ends thereof at least one panel anchoring member attached to the tension member and embedded within the panel at the outer edge portions thereof such the tension members prevent spreading of the panel so that loads are transferred from an upper surface of the panel to the beams by forming a compressive arch within the panel;    and each tension member having adjacent respective ends thereof at least one further anchoring member attached to the tension member and exposed from the panel.    
   
   
       24 . The panel according to  claim 23  wherein each of the further anchoring members and the panel anchoring members comprises an upstanding shear transfer stud with a bottom end fastened to the respective tension member.  
   
   
       25 . The panel according to  claim 23  wherein each shear stud has a shaft and an upper head of greater transverse dimension than the shaft.  
   
   
       26 . The panel according to  claim 23  wherein the tension member extends to a position beyond an outer edge of the panel and wherein the at least one further anchoring member is located on the tension member at the position beyond the outer edge of the panel.  
   
   
       27 . The panel according to  claim 23  wherein the compressive arch in the panel avoids the requirement for transversely extending tension reinforcement in the panel.  
   
   
       28 . The panel according to  claim 23  wherein a lower surface of the concrete panel is recessed at a center area between the outer edge portions such that tension member is exterior to the panel at the center area.  
   
   
       29 . The panel according to  claim 23  wherein the concrete of the panel contains staple fibers for micro-crack reinforcement.