Ductile fibre reinforced cementitious composites (DFRCC) for improved corrosion durability of reinforced concrete columns

Abstract

This paper reports the results of an experimental program on the effectiveness of ductile fibre reinforced cementitious composites (DFRCC) in retarding the corrosion of steel, corrosion induced damage and post-corrosion structural behaviour of reinforced concrete (RC) columns. Two series RC columns are included in this program. The first series consists of ordinary RC columns that are subjected to an accelerated corrosion regime. The second series consists of two columns that are similar to first two series in every aspect, except that the ordinary concrete in the column is replaced with a ductile DFRCC material. Two types of DFRCC materials are considered: a hybrid-fibre DFRCC containing 1.5 vol.% PVA fibers and 1 vol.% steel fibers and a mono-fibre DFRCC containing 2.5 vol.% PVA fibers. Specimens of the second series are also subjected to a regime of accelerated corrosion. Corrosion damage, including the possible development of spalling and/or delamination, is monitored in each specimen using a specially-fabricated mechanical expansion collar. Based on the collective findings from theoretically-estimated steel losses, visual recordings of corrosion damage, and measurements of the tendency of cover delaminate, it was concluded that the steel reinforced DFRCC columns had a remarkably higher resistance against reinforcement corrosion compared to the ordinary RC columns. The corrosion damaged DFRCC columns also exhibited about 23-64% higher failure load than that of corrosion damaged RC columns and no sign of spalling of cover of columns in the structural test.