Study of new RC structures using ultra-high-strength fiber-reinforced concrete (UFC) - The challenge of applying 200 MPa UFC to earthquake resistant building structures

This paper describes the seismic behavior of new reinforced concrete (RC) building structures using ultra-high-strength fiber-reinforced concrete (UFC) with 200 MPa strength. A series of tests of columns and frames in UFC buildings subjected to seismic forces were conducted to obtain basic data of their behavior and to provide guides for design and construction. The test results are summarized as follows. 1) UFC, which is basically a brittle material, could be well confined with high-strength lateral reinforcements. 2) Stable behavior of columns could be obtained even under very high axial compression when they were well confined with high-strength lateral reinforcements. 3) Steel-fibers in UFC significantly enhanced the shear resistance of columns and frames. Analytical investigations indicated that the shear behavior of a column and a frame can be well evaluated by considering the contribution of steel fibers to the tensile resistance of UFC.