Experimental Study on Seismic Capacity of Reinforced Concrete Composite Columns Based on a High-ductile Fiber Cementitious Composite

The authors examined the application of a high-ductile fiber cementitious composite (HDFC) to develop seismicimproved reinforced-concrete columns. HDFC was manufactured to show high-ductile tensile strains above 2.0%, sustaining tensile stress after cracks and developing multiple micro-cracks while avoiding crack localization. To seismically improve a reinforced-concrete column, a precast box made of HDFC was applied locally at the flexural critical region in the column plastic hinge zone; a construction process is also proposed. In seismic performance evaluations of the developed column, a series of cyclic load tests was conducted by manufacturing four column specimens. It was shown from experiments that the developed reinforced concrete and HDFC composite columns showed not only improved seismic performances but also minimized bending and shear cracks in the flexural critical region of the column.