STEEL CLAMP AS EXPRESS METHOD OF REINFORCEMENT OF REINFORCED CONCRETE DAMAGED COLUMNS

Abstract

Based on the field studies and determination of the parameters of the stress-strain 
state, as well as the nature of the operation of reinforced concrete I-beam columns damaged during 
operation and during hostilities, a general method for determining the residual bearing capacity of 
elements was created. The article presents a method for determining the residual bearing capacity of 
damaged compressed reinforced concrete columns with damage at an angle, when the damage front 
is not parallel to one of the main axes of the section and the reinforcement of the steel cage. 
Prerequisites for the calculation of damaged reinforced concrete I-columns are proposed: the 
hypothesis of flat sections is accepted; stresses in the compressed zone are distributed uniformly with 
intensity ηf cd ; the stresses in the reinforcement are taken depending on the height of the compressed 
zone of concrete, the forces in the tension zone are perceived by the reinforcement and are accepted 
within the calculation of tension f t ; the work of tensioned concrete is not taken into account; the 
condition of parallelism of force planes is accepted (the plane of action of external and internal forces 
coincide or are parallel,  depending on the design case); the  reduced bearing capacity of  exposed 
reinforcing bars is taken into account; damage front is a straight line. Reinforcement clip branches 
are taken into account as additional reinforcement. 
Equilibrium equations are composed. The proposals set forth in the article are based on the 
main provisions of the current norms and expand the scope of their use. 
The  proposed  method  for  determining  the  residual  bearing  capacity  of  reinforced  concrete 
compressed elements of the tee profile, damaged during operation and reinforced with a steel cage, 
is statistically justified and reliable. This allows the calculation method to determine the possibility 
of further trouble-free operation of structures. 
A system of equations has been created that takes into account all the variety of shapes and 
sizes of the cross section of the element as a whole, the shapes and sizes of the compressed concrete 
zone.  The  reliability  of  these  proposals  is  confirmed  by  comparison  with  data  obtained 
experimentally, and statistical processing of such a comparison. The deviation variation coefficient 
is 0,125.