Technical standards for railway steel-concrete hybrid structures were published for the first time in 1998. Since then, various technical advances in hybrid structures have been made, and the technical standard, “Design Standards for Railway Structures and Commentary (Steel-Concrete Hybrid Structures)” (hereafter, “Hybrid Structures Standard”) has been revised in January 2016. The revised Hybrid Structures Standard incorporates the latest technical findings as a performance verification type design system. As a summary of this Hybrid Structures Standard, this paper introduces the definition of hybrid structures, the target structures covered by this standard, the overall document structure, the required performance of structures, the revised methods for strength and deformation capacity of steel reinforced concrete members and concrete filled steel tube members, new verification methods for joint and so on.

The ISO 55000 series of Asset Management System Standards was launched in January 2014, and the Japanese Industrial Standards (JIS) is working to establish a corresponding standard. Further, the first instance of ISO 55001 certification in Japan was reported to be the sewerage asset management system of Sendai City. This paper presents the basic principles of the ISO 55001 standard and its specific contents, and gives an overview of the history of its establishment based on the High Level Structure, the new standardized way of drafting future ISO management system standards, such as the ISO 9001 standard. This paper also touches upon the impact of ISO 55001 on Japanese organizations that require asset management.

Long-distance pumping of concrete 2 076 meters (with relay pumps installed at two locations) was executed for the placement of invert concrete for the construction of a caisson for the Gotanda River Spillway Discharge Section ordered by Kawasaki City. Having quantified the required performance of concrete to be applied to long-distance pumping in the process of considering the mix proportions of the invert concrete, the authors focused on thixotropy as a factor that affects pumping load. Through laboratory tests and demonstration experiments, the use of AE and high-range water reducing agent with high dispersion effect retention and pumpability enhancing admixture were found to be effective for the reduction of thixotropy. Further, in actual construction, quality control was performed to suppress pipe blockages due to segregation and increased pumping load.