Damage to buildings around strong ground motion observation points was surveyed and relationship between recorded strong ground motion and damage to buildings was investigated. Less than 0.5s short period was dominated in most records, but 1-2s period was dominated in the Kawaguchi-machi record, therefore, the record was very destructive and brought about severe damage. Damage to reinforced concrete buildings was small compared to damage to wooden houses.

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The Electron Probe Micro Analyzer (EPMA) has come into use during the past several years in diagnosising deterioration of concrete structures and ascertaining effectiveness of repair work. In many case, however, useful information is not being obtained. The objective of this paper are to describe what characteristics are possessed by EPMA and to indicate the proper method by which it should be used.

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This paper, first, reviews the basic common steps of wind design methods of major international building codes and standards (Australia, Canada, EU, Japan and U.S.A.), regarding the effects of various factors, such as mean wind loads, fluctuating wind loads, turbulence intensity and gust loading factors, on wind design of buildings, along with the comparison among those codes and standards. The calculated results according to the codes and standards on assumed 200 m and 500m tall buildings are also compared. Second, this paper discusses structural design criteria adopted for five recently constructed ultra-tall buildings in Asia (Kuala Lumpur, Shanghai-two buildings, Taipei and Yokohama). The wind design levels and the seismic design levels used for these five ultra-tall buildings are summarized in terms of overall drift induced in these buildings. Finally, super-ultra-tall buildings with the multi-core system like a 705m ultra-tall building to be constructed at Dubai in 2008 are suggested for densely populated cities in the future.

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We researched the temperature dependency of the expansion material and the effective Young's modulus in cast -in-place PC slab. And, the initial value used for the thermal stress analysis was examined. In addition, the outline stress value to be able to judge the effect of the expansive additive quantitatively and thermal stress by heat of hydration was re-searched.

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Recently, determination of the water content of freshly mixed concrete is required in addition to slump, air content and quantity of chloride ion on construction site. More than ten methods to determine the water content are developed and applied in practice. In this paper determining test method of freshly mixed concrete with chloride solution is described. A given mass of freshly mixed concrete is intermixed with a chloride solution of a given strength and volume. The chloride ion concentration of the intermixed solution is directory related to the water content of the concrete sample. And generally the concentration is determined by volumetric titration or coulometric reference technique. Authors developed the method with coulometric titration chloride meter. General charactaristics of the methods, practical procedure and applied results are described.

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In Japan, it became a great matter that a lot of RC columns have been suffering from the serious damage due to ASR. Although some countermeasures were established about 15 years ago, they could not always mitigate ASH completely. Recently, it was founded that reinforcing bars in ASH-damaged concrete structures were also failured. The authors carried out the series of study on ASR mitigation-effect and strengthing-effect of repair and retrofitting methods. The longterm exposure test using real-size specimens and inspection of retrofitted real columns was performed. This paper described their ASH. mitigation-effect.

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