In view of the diversification trend of composite structures, the Architectural Institute of Japan has revised its structural design standards system that was centered on the “Standards for Structural Calculation of Steel Reinforced Concrete Structures”, and constructed a new structural design criteria system based on the “Design Standard for Composite Structures”, a superordinate standard that encompasses the entire range of composite structures. The “Design Standard for Composite Structures” published this time consists of structural design criteria related to current composite structures and common design criteria of joints, etc. Furthermore, in consideration of future composite structures, it features also content that will contribute to the establishment of design methods for newly developed composite structures.

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Architectural Institute of Japan (AIJ) revised the Standard for Structural Calculation of Steel Reinforced Concrete Structures (SRC Standards) in 2014. This revision, which is based on the contents of the existing SRC standard, maintains it's investigation framework for allowable stress based design and horizontal load bearing capacity. The main revisions this time are the revision of the provisions concerning design methods for column bases and wall members, the indication of the restoring force characteristics and deformation capacity of members for which flexural failure dominates, and the removal of provisions concerning concrete-filled steel tube structures. No substantial revisions have been made besides those for column bases and wall members. However, recent research findings have been incorporated in the explanations, along with adjustments for the sake of consistency with revised specifications, criteria and guidelines related to SCR standards. This report provides an overview of the resulting revised SRC standard.

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Following the accident at the Fukushima Daiichi nuclear power plant in the Great East Japan Earthquake, a large amount of water contaminated with radioactive materials has built up on the premises. The processing, temporary storage and leakage prevention of this contaminated water has become a major issue. Processing, disposal and recycling technology for debris contaminated by radioactive substances is also needed. In this paper, we review reports, research and technical proposals related to these issues from the perspective of concrete engineering.

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Bending loading tests on RC beams of different effective heights were conducted and the results were compared with those yielded by typical bending crack width calculation formulas (Japan Society of Civil Engineers Standard Specification for Concrete Structures, ACI 318-11, BS EN 1992-1-1 : 2004). For each formula, there were cases of sectional geometries and rebar placements for which the maximum bending crack width value was underestimated. Moreover, in addition to the covering and the on-center spacing of rebars as factors controlling the bending crack width, consideration of the influence of the effective height was demonstrated to be of importance in order to create a highly accurate bending crack width calculation formula.

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The surface layer of concrete structures is an important part that greatly affects the durability of structures, and its quality is determined to a large extent by construction factors. The factors that affect surface quality were analyzed through the use of rational assessment methods, and cases found to contribute to quality improvement are introduced herein. Further, from the analysis results, bleeding control type AE water reducing agent was focused on as one of the rational methods for improving surface quality, and its characteristics, application examples, and surface quality improvement effect are discussed.

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[in Japanese]

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[in Japanese]

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