FUNDED RESEARCH

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Determining the Effects of Low-Cycle Fatigue on the Seismic Performance of Rebar and Couplers for Critical Bridge Members ($200,000): May 2005 – December 2005. I Left my Academic Position before completing the project.

Submitted to California Department of Transportation in response to RFP and funded in April 2005. In seismic events, the longitudinal reinforcement in concrete elements may undergo large strain reversals of typically one to five fully reversed cycles. This causes significant changes to the mechanical properties of the steel reinforcement and couplers, and as a result the strength and ductility of the concrete element changes. The purpose of this study is to develop a computer simulation based on a developed analytical model to assess the vulnerability of concrete bridge elements after seismic events and to verify this model using experimental tests.

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Knowledge Based Computer Support Environment for the Reuse of Design Information in Structural Design ($25,600): December 2002 – April 2005:

Using previous designs to generate new designs is desirable because it saves time and effort, and because the concept has proven effective in previous situations. In this research, a conceptual model is developed to support the use of prior experiences to generate a solution for a new problem by using the entire previous design or part of it as a template to generate a new one through the use of innovative case adaptation techniques. The model works like a large spreadsheet to establish relations between various design parameters and supports the interface with a library of design tools to calculate the configuration of the new design based on its loads and structural configurations.

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Seismic Evaluation of the Performance of Retrofitted and Repaired Brick Walls by Means of Expansive Epoxy Injection (Approx. $50,000):  March 1998 - August 2000:

A pioneer technique to repair unreinforced masonry walls cracked during past seismic events, or to retrofit existing brick walls to meet the current code requirements, is subjected to experimental investigation. Such walls are very common in historical buildings. The walls are injected by ceramic foaming material developed by Delta Plastics Company.  After the material is shot into walls, it expands, bonds and hardens like rock. Unlike Carbon fiber, this injection technique does not affect the appearance of these historical walls and consequently it preserves their historical value. The seismic performance and ductility of the plain brick walls were first measured by applying cyclic loads on them to failure. The broken walls were repaired using the Ceramic Foam and tested again. In addition, unbroken walls strengthened with Ceramic Foam and composite Carbon Fiber material were tested. Performance of all walls were studied and compared to prove the effectiveness of the Ceramic Foam material in the retrofittingand repairing of walls. Video clips of the tests can be viewed at my web site

See Testing Video and Report.