ABSTRACT
This paper presents an overview and main findings of a shake table test of a precast bridge column that was designed to accelerate bridge construction and to provide superior seismic performance through selfcentering and reduction of damage. Self-centering was achieved by posttensioning the column using unbonded carbon fiber reinforced polymer (CFRP) tendons. Furthermore, ultra-high performance concrete (UHPC) was used in the plastic hinge of the bridge column to reduce damage under strong earthquakes. The precast bridge column was connected to a precast footing using pocket connection. The main objectives of this study were: (1) to investigate the effectiveness of CFRP tendons in minimizing residual displacements under strong earthquakes, (2) to evaluate the seismic response of a precast square column connected to a precast footing using a pocket connection, and (3) determine the feasibility of using ultra-high performance concrete (UHPC) in the plastic hinge zone to minimize column damage.
To accomplish the objectives of the study, a 1/3 scale of a precast novel column model was constructed and posttensioned using CFRP tendons. The column was designed according to AASHTO Guide Specifications for LRFD Seismic Bridge Design (2014). Figures 1, 2 show the test model. The 1994 Northridge earthquake acceleration history recorded at the Rinaldi station was simulated in the shake table test because of its tendency to cause large permanent displacements in conventional reinforced concrete columns. Results of the shake table test demonstrated that CFRP tendons effectively eliminated the residual displacements at different levels of earthquake. Noncorrosive and mechanical properties of CFRP tendons make it attractive to be used as a replacement for the unbonded steel tendons in bridge columns. In addition, the pocket connection at the footing performed well without any significant damage and provided the full fixity at the base. Geometry of the test model. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig170_1.tif"/> Shake table test setup. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig170_2.jpg"/>
