RC column repaired with hpfrcc and confined with cfrp: numerical analyses to evaluate the column section capacity

This paper presents a numerical study to evaluate the behavior of reinforced concrete (RC) columns with circular section repaired and retrofitted by high-performance fiber-reinforced cement composites (HPFRCC) jackets and external carbon fiber-reinforced polymer (CFRP) wrapping. The column damage is due to degradation of concrete and steel rebars for effect of the corrosion. Different HPFRCC mix designs were considered to repair the column assuming different fiber types (polyethylene, stainless steel) and volume contents (1% or 2%). These HPFRCC concretes were developed and tested experimentally at the lab of the University of Roma Tre (Salvador Filho et al. in Mechanical properties of HPFRCC reinforced with different types and volumes of fibres [1]). The numerical analyses were conducted by means of fiber models using the software OpenSees (OpenSees structural software [computer software]. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, [2]) applying a vertical load and a displacement history (section rotation). The analyzed sections represent the undamaged section, the section damaged for effect of rebar corrosion, and the repaired and retrofitted sections. The first numerical results about the section strength capacities for each type of repair material are discussed.