Unreinforced shrinkage compensating concrete floor slabs

Abstract

A shrinkage-compensated concrete slab is formed with no reinforcing structural bars therein, but with plates around its periphery so as to restrain expansive and shrinkage forces. The plates can be made of steel and welded together at their ends, and can include studs extending inwardly from inner surfaces thereof for attachment to the slab.

1 . A shrinkage-compensated concrete structure which comprises a concrete slab having no reinforcing structural bars embedded therein and a plurality of connected plates positioned around a periphery of the concrete slab to elastically restrain expansive and shrinkage forces developed by the concrete slab during setting.  
   
   
       2 . The structure as defined in  claim 1 , wherein the plates are made of steel.  
   
   
       3 . The structure as defined in  claim 2 , wherein the steel plates include attachment studs which extend from inner surfaces thereof into the concrete slab.  
   
   
       4 . The structure as defined in  claim 2 , wherein said steel plates are connected end-to-end by welds.  
   
   
       5 . The structure as defined in  claim 1 , wherein the plates are made of plastic.  
   
   
       6 . The structure as defined in  claim 1 , wherein the concrete slab is square in shape.  
   
   
       7 . The structure as defined in  claim 1 , wherein the concrete slab is rectangular in shape.  
   
   
       8 . The structure as defined in  claim 1 , including a plastic sheeting beneath the concrete slab.  
   
   
       9 . A method of providing a shrinkage-compensated concrete structure which comprises forming a concrete slab which has no reinforcing structural bars embedded therein, and encasing a periphery of said concrete slab with a plurality of plates to elastically restrain expansive and shrinkage forces developed by the concrete slab during setting.  
   
   
       10 . A method as defined in  claim 9 , including connecting said plurality of plates end-to-end.  
   
   
       11 . A method as defined in  claim 10 , where said plates are made of steel and are welded end-to-end.  
   
   
       12 . A method as defined in  claim 9 , wherein the coarse aggregate size and shape in the concrete are adjusted to increase internal compression.