1672 1 Snr Researcher, IISEE, Building Research Inst, Ministry of Construction, Tsukuba, Japan Email: fukuyama@kenken.go.jp 2 Research Engineer, Technical Research Institute, Fujita Corporation, Atsugi, Japan, Email: ysato@fujita.co.jp 3 Professor, ACE-MRL, Dept of Civil and Env Eng, The University of Michigan, MI, U.S.A., Email: vcli@engin.umich.edu 4 Professor, Dept of Architecture, Faculty of Eng, Science Univ of Tokyo, Tokyo, Japan Email: ymatsu@rs.kagu.sut.ac.jp 5 Professor, Dept of Architecture, Faculty of Eng, Tohoku Univ, Sendai, Japan Email: mihashi@timos.str.archi.tohoku.ac.jp DUCTILE ENGINEERED CEMENTITIOUS COMPOSITE ELEMENTS FOR SEISMIC STRUCTURAL APPLICATION Hiroshi FUKUYAMA 1 , Yukihiro SATO 2 , Victor C LI 3 , Yasuhiro MATSUZAKI 4 And Hirozo MIHASHI 5 SUMMARY A collaborative effort between US and Japanese researchers has focused on the development of high-performance elements for seismic structural applications based on a new materials technology as an Engineered Cementitious Composite (ECC) designed using micromechanical principles. ECC exhibits strain-hardening with strain capacity in excess of 1% in tension and multiple cracking properties. The excellent identical properties of ECC make it especially suitable for critical elements in seismic applications where high performance is required. Applications of ECC to energy absorption devices and damage tolerant structural elements are considered to meet the performance requirements of structures under the performance based engineering. These new structural elements with ECC are expected to reduce the seismic response and damage of structures. Objective of this research is to investigate the upgrading effects on structural performance of ECC reinforced elements. The ECC employed in this research is Polyvinyl Alcohol (PVA) fiber reinforced mortar. A tension-compression reversed cyclic test of ECC material and a structural test with six beam elements were conducted. This paper summarizes the basic mechanical properties of PVA-ECC and structural performance of the PVA-ECC reinforced beams. The micromechanics concepts, which support the development of ECC, are also briefly presented. Results of the beam test indicate that brittle failures as shear failure and bond splitting failure observed in the RC beams can be prevented by using PVA-ECC in place of the concrete. As a result, the beams with PVA-ECC indicate excellent ductile manner. The shear crack widths up to 5 % rad. in deflection angle in the beams with PVA-ECC were less than 0.3 mm, which is the maximum limit from the view of durability. Through this test, it can be clarified that ECC has much feasibility to upgrade the structural performance and damage tolerance of structural elements. INTRODUCTION One of the lessons from the Japanese current destructive earthquakes including the 1995 Hyogoken-Nanbu Earthquake (Kobe Earthquake) is that most new buildings designed according to the current seismic codes showed fairly good performance with the view of preventing severe damage and/or collapse for life safety. However, the problem was that the seismic performance of buildings was widely ranged from the level of collapse preventing to function keeping, which have not been identified by the current seismic codes. It is, therefore, strongly needed to develop the more rational seismic design codes based upon the performance-based design concept. The performance on seismic resistance of buildings including structural safety and functional soundness during and/or after earthquake, and reparability after earthquake may be explicitly explained. The Japanese Building Standard Low is now under revising to be performance-based regulations. Since the low is a minimum requirement, a new evaluation and statement system of building performance beyond the code requirement is also under developing. Then it is a high priority issue to develop the new structural technologies to meet the high level of structural performance requirement.