Fracture-inducing lid for isolation pocket form

Abstract

An isolation pocket form is placed on around a footing for a support column, and then covered with a lid which has a sharp peripheral rim extending upwardly. Concrete is then poured around and over the form and lid, forming an initially continuous concrete floor which can be used as a casting bed for making wall slabs. The sharp-bottomed grooves produced in the concrete by the rim are preferential fracture sites, so that, after the wall slabs have been removed, the concrete portion overlying the isolation pocket can easily and cleanly be broken out.

1 . A lid for an isolation pocket form for use in concrete floor construction, said form having a wall bounding a closed area and a lid seating surface, 
 said lid being shaped and sized to cover the closed area and to rest upon said seat,    the lid having an upper surface and a peripheral rim extending upward above said upper surface,    whereby concrete can be poured and cured over said lid so as to form a slab with an uninterrupted upper surface on which tilt-up wall slabs can be cast, said peripheral rim producing a groove in the concrete to generate clean fractures therein when pressure is applied to an area of the concrete floor overlying the lid.    
   
   
       2 . The invention of  claim 1 , wherein the lid has an array of reinforcing ribs to give the top strength and rigidity.  
   
   
       3 . The invention of  claim 1 , wherein said rim has a substantially sharp top edge to facilitate fracture and removal of overlying concrete.  
   
   
       4 . The invention of  claim 3 , wherein said sharp top edge lies substantially in a horizontal plane parallel to said seat, so that the groove produced in the concrete floor is at a substantially uniform depth below the surface of the floor.  
   
   
       5 . The invention of  claim 1 , wherein said rim extends at least one inch above said upper surface.  
   
   
       6 . A method of pouring and curing a concrete floor having isolation pockets, and using the floor temporarily as a casting bed for wall slabs, said method comprising steps of: 
 placing at least one footing for a support column,    placing an isolation pocket form on or around the footing,    covering the form with a removable lid having a raised peripheral rim designed to provide preferential fracture lines subsequently hardened concrete, the rim being below the design elevation of the floor,    placing aggregate or fill material around the form up to a level substantially below the level of the lid rim,    pouring concrete over the aggregate or fill material and the isolation pocket form to a level above the level of the rim so that the isolation pocket form is completely covered by the concrete,    allowing the floor to harden,    applying force to the floor above the isolation pocket form so as to fracture the concrete along said preferential fracture lines, and then    removing the concrete within the fracture line from above the isolation pocket form.    
   
   
       7 . The method of  claim 6 , comprising, between the allowing an applying steps, steps of 
 pouring a least one wall slab on top of said floor,    allowing the wall slab to harden, and    removing the wall slab from above the isolation pocket.    
   
   
       8 . The method of  claim 6 , comprising a further step of removing the lid from the isolation pocket form.  
   
   
       9 . The method of  claim 8 , comprising a further step of attaching a support column to the footing.  
   
   
       10 . The method of  claim 9 , comprising a further step of filling the pocket around the column with concrete.