US - Japan Composite and Hybrid Systems Research Program


Title of Project Engineered Cementitious Composites for Ductile R/C Elements
Principle Investigator Victor C. Li
Title Visiting Professor of Civil Engineering
Institution University of Michigan
Mailing Address Dept. of Civil Engineering and Environmental Engineering, University of Michigan, 2326 G. G. Brown Building, Ann Arbor, MI 48109-2125
Email vcli@uxmailust.hk
Research Associates T. Kanda
Research Sponsor National Science Foundation

Objectives

This proposal is aimed at establishing the proper design of a ECC material. In this first phase of the research, focus is placed on the formulation of an ECC that meets practical constraints of cost and processing. Simultaneously, constitutive models will be constructed based on material element tests. Such constitutive models will be used for predicting the load response of structural elements fabricated from ECC. The interaction between steel and ECC will also be experimentally investigated. The ultimate objective of this research is to transfer the extremely ductile behavior of ECC material into enhancement of seismic response of structural members and systems.

Technical Approach

For material design, the micromechanics approach will be adopted. This employs knowledge of the interaction between fiber, interface, and cementitious matrix to relate these material structures to composite mechanical behavior. The relation is then used to tailor the material structure for composite ductility performance while meeting cost and processing constraints. For structural design, a combination of component testing and FEM prediction is adopted. The testing uses the ECC material in components critical for maintaining system performance under seismic load. The FEM analysis employs the constitutive model derived from material element tests. The investigation is designed around the performance driven design approach (PDDA) framework that allows findings in material and structural response to provide feedback in necessary improvement of each.

Summary of Research Results to Date

The testing, analysis, and design of a PVA fiber-based ECC has been completed. Initial FEM study of the structural response of a shear panel for open wall retrofit made form such a PVA-ECC has also been performed Research findings are reported in the references given below.

References

Kanda, T., and V. C. Li. Interface Property and Apparent Strength of a High Strength Hydrophilic Fiber in Cement Matrix. (Accepted for publication in ASCE Journal of materials in Civil Engineering. April 1997.)

Li, V. C. Damage Tolerance of Engineered Cementitious Composites. In Advances in Fracture Research. Proceedings 9th ICF Conference on Fracture, Sydney, Australia. Eds.: B. L Karihaloo, Y. W. Mai, R. I. Ripley, and R. O Ritchie. U.K.: Pergamon. 1997. pp 619-630.

Kabele, P., et al. Use of BMC for Ductile Structural Members. Proceedings International Symposium on Brittle Matrix Composites (BMC-5). Warsaw: October 1997.

Additional Information

http://www.engin.umich.edu/dept/cee/research/acemrl/ACEMRL.html

Keywords

innovative materials, performance and characterization of materials and components; experimental investigation; analytical investigation; design methodology
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