A Study of Concrete Bridge Columns Using Innovative Materials Subjected to Cyclic Loading

Abstract

This Innovations Deserving Exploratory Analysis (IDEA) project evaluated the application of superelastic shape memory alloy (SMA) reinforcement in combination with engineered cementitious composites (ECCs) in bridge columns to minimize earthquake damage. Based on initial evaluation, Nitinol SMA and ECC compositions were selected for application in bridge columns. An analytical study was performed to determine optimum material properties and configuration for the concrete column. Bridge columns incorporating a combination of SMA and ECC or conventional concrete were constructed and subjected to quasi-static cyclic tests. The first column (RSC) utilized conventional concrete and steel reinforcement; the other two (RNC and RNE) utilized ECCs in the plastic hinge. The average ratios of residual to maximum displacement in RSC, RNC, and RNE indicated substantial benefits of using innovative materials. RNE experienced the least damage and highest drift capacity among the three columns. The test results showed the promise of SMA and ECC in improving serviceability of bridges after earthquakes. The final report includes important experimental and analytical data to help develop design guidelines for improving the seismic response of bridge columns using SMA and ECC materials.