Design and Measured Behavior of a Hybrid Precast Concrete Wall Specimen for Seismic Regions

Abstract

This paper presents the measured behavior from the testing of a 0.4-scale “hybrid” precast concrete wall specimen under reversed-cyclic lateral loading and provides an assessment of the seismic design and analysis of the wall by using the experimental results. The hybrid precast wall system investigated in the paper utilizes a combination of mild (i.e., Grade 400) steel and high-strength unbonded posttensioning (PT) steel for lateral resistance across horizontal joints. A seismic design procedure that conforms to ACI 318 and ACI ITG-5.2 was used for the design of the test specimen based on ACI ITG-5.1. The behavior of the specimen was measured with conventional data acquisition techniques and also full-field digital image correlation of the base panel and the critical joint between the base panel and the foundation, providing unprecedented information on the wall performance. The paper compares these measurements with the design and analytical predictions, focusing specifically on the applied lateral load and displacement, energy dissipation, behavior of the steel reinforcement, and behavior along the horizontal joints. The test specimen was not able to reach the expected ultimate drift level owing to a combination of poor unconfined concrete strength and poor placement of the confinement reinforcement at the toes. However, the performance of the wall up to the failure point was consistent with the predicted behavior based on both the design procedure and the analytical models.