Seismic-improved reinforced-concrete composite column using a high-ductile fiber cementitious composite precast box

ABSTRACT The purpose of this study is to investigate the applicability of the high-ductile fibre cementitious composite to develop seismically improved reinforced concrete columns. The high-ductile fibre cementitious composites were fabricated to exhibit high-ductile tensile strains as above 2.0% with sustaining the tensile stress after cracks and to develop multiple micro-cracks while avoiding crack localisation. In order to seismically improve the reinforced concrete column, the precast box made of the high-ductile fibre cementitious composite was locally used at the flexurally critical region in the column plastic hinge zone, and the construction process was also proposed. In seismic capacity evaluation of the developed column, cyclical loading tests were carried out by using four column specimens fabricated. It was revealed, from experiments, that the developed reinforced concrete and the high-ductile fibre cementitious composite columns showed an improvement of the seismic capacity of the column as well as a minimisation of flexural and shear cracks in the bending critical region of the column