Method of reducing the width of cracks in masonry

Abstract

The invention relates to a method to reduce the width of cracks that may be induced in masonry. The reinforcement strips comprise at least two straight, substantially parallel reinforcement wires connected to each other by means of a wire connecting structure. The reinforcement wires have a design yield strength f yd equal or higher than 550/γ s N/mm 2 and an equivalent diameter d equal or lower than 4 mm. The reinforcement strips have a resistance F against loads applied on said reinforcement strip and a design value of resistance F d . The reinforcement strip embedded in said joint has a bond capacity F bok and a design bond capacity F bod . The design yield strength f yd and the diameter d of said reinforcement wires are chosen so that the design value F d of the reinforcement strip is equal or lower than the design bond capacity F bod of the reinforcement strip.

1 . A method to reduce the width of cracks that may be induced in masonry, said masonry comprising layers of bricks and joints, said method comprising the step of reinforcing at least one joint with reinforcement strips, said reinforcement strips comprising at least two straight, substantially parallel reinforcement wires connected to each other by means of a wire connecting structure, said reinforcement wires have a design yield strength f yd  equal or higher than 550/γ s  N/mm 2  and an equivalent diameter d equal or lower than 4 mm, said reinforcement strip having a resistance F against loads applied on said reinforcement strip, said resistance F having a design value of resistance F d , said design value F d  being equal to the cross-sectional area of the reinforcement wires in tension multiplied by the design yield strength f yd , said reinforcement strip embedded in said joint having a bond capacity F bok , said bond capacity F bok  being determined by European Standard EN846-2, said bond capacity F bok  having a design bond capacity F bod , characterized in that said design yield strength f yd  of said reinforcement wires and said diameter d of said reinforcement wires being chosen in such a way that said design value F d  of said reinforcement strip is equal or lower than said design bond capacity F bod  of said reinforcement strip and that said reinforcement wires are provided with a plurality of ribs. 
     
     
         2 . A method according to  claim 1 , wherein said reinforcement wires comprise steel wires. 
     
     
         3 . A method according to  claim 1 , wherein said wire connecting structure comprises a steel wire or a number of steel wires. 
     
     
         4 . A method according to  claim 1 , wherein said reinforcement wires are connected to each other by welding said wire connecting structure between two adjacent reinforcement wires. 
     
     
         5 . A method according to  claim 1 , wherein said reinforcement wires have a design yield strength f yd  higher than 600/γ s  N/mm 2 . 
     
     
         6 . A method according to  claim 1 , wherein said reinforcement wires have an equivalent diameter equal or lower than 3.65 mm. 
     
     
         7 . A reinforcement strip comprising at least two straight, substantially parallel reinforcement wires connected to each other by means of a wire connecting structure, said reinforcement wires having a design yield strength f yd  equal or higher than 550/γ s  N/mm 2  and an equivalent diameter d equal or lower than 4 mm, said reinforcement strip having a resistance F against loads applied on said reinforcement strip, said resistance F having a design value of resistance F d , said design value F d  being equal to the cross-sectional area of the reinforcement wires in tension multiplied by the design yield strength f yd , said reinforcement strip embedded in said joint having a bond capacity F bok , said bond capacity said bond capacity F bok  being determined by European standard EN846-2, said bond capacity F bok  having a design bond capacity F bod , characterized in that said design yield strength f yd  of said reinforcement wires and said diameter d of said reinforcement wires being chosen in such a way that said design value F d  of said reinforcement strip is equal or lower than said design bond capacity F bod  of said reinforcement strip and that said reinforcement wires are provided with a plurality of ribs. 
     
     
         8 . A reinforcement strip according to  claim 7 , wherein said reinforcement wires comprise steel wires. 
     
     
         9 . A reinforcement strip according to  claim 7 , wherein said wire connecting structure comprises a steel wire or a number of steel wires. 
     
     
         10 . A reinforcement strip according to  claim 7 , wherein said reinforcement wires are connected to each other by welding said wire connecting structure between two adjacent reinforcement wires. 
     
     
         11 . A reinforcement strip according to  claim 7 , wherein said reinforcement wires have a design yield strength f yd  higher than 600/γ s  N/mm 2 . 
     
     
         12 . A reinforcement strip according to  claim 7 , wherein said reinforcement wires have an equivalent diameter equal or lower than 3.65 mm. 
     
     
         13 . A reinforcement strip according to  claim 7 , wherein said wire connecting structure is provided with protuberances protruding from the plane comprising said reinforcement wires and forming spacing elements which allow an embedment of said reinforcement wires in mortar. 
     
     
         14 . A reinforcement strip according to  claim 13 , wherein said protuberances of said wire connecting structure are present at both side of said plane comprising said reinforcement wires. 
     
     
         15 . Masonry comprising layers of bricks and joints, whereby at least one joint is reinforced by a number of reinforcement strips as defined in  claim 7 .