Retrofitting of square reinforced concrete column by welded wire mesh jacketing with consentric axial load

Abstract

Structural failure to carry the earthquake load is due to several factors such as the column design that ignores ductility or restraint, bad column detailing so the column performance decreases than the previous planning, besides the planner ignores the concept of "strong columns weak beams". One way to increase the existing structure column ductility is retrofitting the column by wrapping the column using Welded Wire Mesh (WWM). The research is to determine the effectiveness of WWM as a column restraint material and determine the model of reinforced concrete column stress-strain relationship curves retrofitted by using WWM. The experimental testing used a square column with an initial size of 150x150mm and covered by WWM then there was a casting to make the size became 220 x 220 mm with three types of columns namely RCH, RCHWWM-1 and RCHWWM-2 with column test specimen height = 800 mm. All columns underwent a compressive test with monotonic concentric axial load. Test result indicates that, there is an increase in compressive strength (f' cc), Confined concrete strain (ϵ'cc) and ultimate concrete strain (ϵ'cu) on RCHWWM-1 and RCHWWM-2 column. For RCHWWM1 Column, f' cc increase = 0.26%, ecc = 87.50%, and ecu = 175.71%, RCHWWM2 Column f' cc increase =-1.65%, ϵcc = 85.00%, and ϵcc = 214.24%. f'cc deviation obtained from Experimental and Theoretical validation ranges from-1.50% to-4.429%, ϵcc deviation ranges from-0.333 to-3.51% and ϵcu deviation ranges from 20.79 to 35.66%.