Reinforced concrete column or bridge pier

Abstract

In a reinforced concrete column or bridge pier includes a plurality of deformed steel bars arranged in a longitudinal direction, and hoops arranged at desired intervals around the deformed steel bars along the longitudinal direction, a sheath covers at least a portion of each deformed steel bar on which shear stress is exerted.

What is claimed is:  
     
         1 . A reinforced concrete column or bridge pier comprising a plurality of deformed steel bars arranged in a longitudinal direction, and hoops arranged at desired intervals around the deformed steel bars along the longitudinal direction, wherein a sheath covers at least a portion of each deformed steel bar on which shear stress is exerted.  
     
     
         2 . The reinforced concrete column or bridge pier according to  claim 1 , wherein said sheath is formed of material which has substantially no resistance to tension and is not deformed by contact pressure in pouring of concrete.  
     
     
         3 . The reinforced concrete column or bridge pier according to  claim 1 , wherein said sheath is made of one selected from the group consisting of steel and plastic.  
     
     
         4 . The reinforced concrete column or bridge pier according to  claim 3 , wherein said sheath made of the steel is 0.25 to 0.32 mm thick.  
     
     
         5 . The reinforced concrete column or bridge pier according to  claim 3 , wherein said sheath made of the plastic is 0.5 to 1.0 mm thick.  
     
     
         6 . A reinforced concrete column or bridge pier comprising a plurality of smooth round steel bars coated with lubricant and arranged in a longitudinal direction, and hoops arranged at desired intervals around said smooth round steel bars along the longitudinal direction.  
     
     
         7 . The reinforced concrete column or bridge pier according to  claim 6 , wherein said lubricant is grease.