Unidirectional fiber reinforced sheets in a thermoplastic matrix

Abstract

In a concrete column supporting an overhead load and having a base and resting on a surface, a process of strengthening the column to increase its ability to withstand atypical physical loading accompanying an earthquake, involving the steps of placing a shell including a thermoplastic sheet around the column, and filling the annular space between the sheet and the column.

1 . In a concrete column supporting an overhead load and having a base and resting on a surface, a process of strengthening the column to increase its ability to withstand atypical physical loading accompanying an earthquake, comprising the steps of: 
 (a) defining a work area about the surface of the column to which said strengthening is to be applied, said work area defined by circumferential marginal edges arranged in spaced-apart relation about the column;    (b) overwrapping said work area with at least one layer of a unidirectionally reinforced thermoplastic sheet, said sheet wrapped around the column;    (c) welding said sheet to said column; and    (d) injecting a filler into an annular space between the sheet and the column, following welding.    
   
   
       2 . The process as recited in  claim 1  wherein the sheets are lap jointed via ultrasonics.  
   
   
       3 . The process as recited in  claim 1  wherein the sheets are applied to the column with a self-tightening winch.  
   
   
       4 . The process as recited in  claim 3  wherein the winch wraps the sheet around the column prior to welding.  
   
   
       5 . The process as recited in  claim 1  wherein the sheet has a thickness of from about 0.1 mm to about 3 mm.