Recent topics on prestressing steel in Japan is described., especially 2008-JIS-revision, various factory applied corrosion protection and their advantages. Delayed curing epoxy resin pre-grouted strands are now applied for longitudinal prestressing as well as transversial prestressing. Since external cables and stay cables are increased, epoxy coated & filled strands and galvanized strands are also getting popular in bridge construction. Advantages and the ductility of 2230 MPa grade high strength steel are also introduced. Some particular cautions on the handling of prestressing steel on sites are also described.

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E-Defense project on the seismic performance of bridge structures is introduced with emphasis on the shake table experiments conducted for two flexural failure and shear failure dominant RC columns which were typically constructed in 1970s and a RC column designed based on the current design criteria.

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Earthquake simulation tests on full-scale reinforced concrete buildings were conducted at E-Defense, the world largest three-dimensional shake-table of NIED in Miki, Hyogo. Tested were a six-story residential building in January 2006 and two three-story school buildings in September to November 2006. The results of the tests and analyses are outlined in this paper.

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Research committee on corrosion evaluation and protection for steel bars (rebars) in concrete (338 Committee) was established in September 2007 as one of research committees in Japan Society of Civil Engineers. In the Committee, the following research works has been carried out; (1) Framework of durability verification for concrete structures deteriorated by chloride attack, (2) Clarification of inspection and monitoring for rebar corrosion in concrete, (3) Protection and repair system for deteriorations due to rebar corrosion and their quantitative performance evaluation method. In this report, the research results on a future strategy of durability verification system for concrete structures in Standard Specifications for Concrete Structures are summarized.

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There is the case to install a steel bracket for end of the abut widening and a steel member for prevention cable for collapse of bridge setting in the existing concrete pier for seismic reinforcement by anchor bolts of the secondary execution. Anchor bolts of the secondary execution are necessary a drilling to the existing concrete deeply and there is a problem in execution characteristics to be in danger to injure inside steel materials. Therefore the fundamental performance of the secondary execution anchor bolt that shortened fixation length to 150 mm was examined, it assumed adoption to the bracket structure that only shear power acted on mainly. As a result, if it could prevent pulling destruction of the concrete at a shallow position, or find the adhesion proof stress of the anchor bolt in the deep part from the destruction starting point more than a form of corn destruction proof stress, and prevent partial compression destruction of the outer layer, it was shown the possibility that could expect reliable performance of load resistance by use for structures that shear resistance is dominant.

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[in Japanese]

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[in Japanese]

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