Japan Architectural Review最新文献

According to the “AIJ Recommendations for Design and Construction of Concrete Filled Steel Tubular Structures”, the ultimate flexural strength of concrete-filled steel tubular (CFST) beam-columns is calculated based on full-plastic strength. However, this approach may overestimate the actual ultimate flexural strength of circular CFST beam-columns, particularly when the diameter-to-thickness ratio is large and/or high-strength materials are used. To address these limitations, a strength evaluation formula that considers the stress gradient and the extreme compression fiber strain of concrete has been proposed for cases beyond the application range of the AIJ Recommendations. Nevertheless, when high-strength materials are employed, the influence of the scale effect of concrete must also be considered, in addition to the stress gradient, to ensure accurate estimation of ultimate strength. In this study, a simplified evaluation method is proposed for calculating the ultimate flexural strength of circular CFST beam-columns, incorporating the stress gradient, extreme compression fiber strain of concrete, and scale effect of concrete. Additionally, the study investigates the appropriate strain at the extreme compression fiber of concrete necessary for accurate strength prediction. The proposed method can accurately evaluate the ultimate flexural strength, regardless of the steel yield strength or the diameter-to-thickness ratio.

Official institutional surveys indicate that an increasing number of library users in Finland believe libraries play a significant role in various aspects of daily life. As libraries diversify their functions, co-location with other public institutions has emerged as a global trend, also evident in Finland. This study posits that spatial design and multifunctional utilization of composite buildings have contributed to increased library visitor numbers. Analysis reveals that some Helsinki libraries have expanded their functions by leveraging lobbies and shared audiovisual equipment within composite buildings. These lobbies are characterized by external visibility, spatial layering that enhances user experience, and diverse access to institutions. In libraries, multifunctional spaces are designed to reflect the functions of composite buildings while considering users' psychological traits: Public libraries co-located with schools create spaces that stimulate children's curiosity, while those in cultural centers create spaces that promote a sense of belonging. The findings suggest that these spatial design elements attract more visitors and cultivate environments conducive to community engagement. Lastly, this study recommends further research into challenges faced by composite libraries to enhance understanding of key considerations in their planning and design. The findings may serve as a valuable reference for spatial strategies in composite libraries worldwide.

The low-velocity impact of thin reinforced concrete (RC) slabs by accidentally dropped objects during building construction raises safety concerns, as complete perforation and back-face debris can injure workers and third parties passing under the slabs. Various methods have been proposed to enhance the impact resistance of RC structural members, such as using high-performance materials or surface strengthening with sheets or strip materials. However, these methods may increase construction costs and procedures, making widespread application challenging. This study proposes an anchoring system for the ends of steel deck plates to suppress debris scatterings. Because steel deck plates are commonly used under RC slabs in building construction as permanent formworks or materials for composite slabs, this system is cost-effective and straightforward. A half-scaled impact test was performed to compare specimens with and without the anchoring system, validating its effectiveness in suppressing debris scatterings. Additionally, a component pull-out test and a finite element analysis were conducted to explore the anchoring system's behavior, followed by an impact analysis considering the pull-out of the anchoring system based on the results of component tests and analyses. The analysis replicated the variation in deck plate detachment behavior with and without the anchoring system.

This future architectural prototype is composed of standardized parts and 3D printed (additive manufactured) metal joints to allow users to build by themselves at a low cost. The structure is assembled with lightweight aluminum pipes where joints are plugged in, in a straightforward, flexible way. The user can freely define the structure layout depending on the site and according to lifestyle and personal preferences. The geometry is the combination of fixed-shape tetrahedrons with non-fixed-shape pentahedrons and hexahedrons that allow the creation of a diversity of soft architectural forms based on uniform-length pipes. By only changing the joints set, the user can change the entire architectural form to adapt to a new site or to accommodate a new requirement when moving or renovating. Other than the joints, all parts, such as aluminum pipes, triangular insulation panels, etc., are standardized and reusable. Referring to the joint manufacturing craftsmanship of traditional Japanese houses and using new additive manufacturing technology that can swiftly output complex shapes, construction is simplified, and customized space can be easily created.

In general, a steel beam is connected to a concrete slab using shear connectors, forming a composite beam. This composite action shifts the neutral axis under bending, resulting in a buckling behavior that differs from that of a bare steel beam. Moreover, the structural performance of composite beams is significantly influenced by the stress transfer mechanism facilitated by the shear connectors. However, the impact of shear connector and slab properties on buckling behavior has not been fully explored. To address this gap, this research first proposes a simplified method. For modeling composite beams that accurately reflects the behavior of shear connectors. Additionally, a comprehensive parametric study is conducted using an experimentally validated finite element analysis (FEA) model, exploring the influence of various shear connectors and slab properties. Based on the analytical results, a modified evaluation index and equation are ultimately proposed to enhance the assessment of composite beam performance.

Japan Architectural Review (JAR), the official international journal of the Architectural Institute of Japan (AIJ), was launched in January 2018 and is in its eighth year in 2025. JAR's overarching objective is to disseminate the latest research results on architecture in Japan to academia worldwide. JAR is a unique journal, covering a wide and complex range of architectural studies, including the latest trends in architectural technology and architectural and design trends in Japan.

The choice of the name “Japan” for this journal's title reflects two major aspirations. One is the “Japan” of the AIJ, and the other is the strong focus on information dissemination from Japan to the world. JAR has a unique purpose and management structure, specializing in the dissemination of information from Japan to the world, rather than expecting papers to be submitted from all over the world. JAR accepts the risk of a limited number of contributions and publications; however, it supports the development of architectural engineering and sciences in Japan.

Eight years after its launch, JAR is steadily growing and obtaining recognition in architectural academia worldwide. The number of paper submissions has steadily increased. Although the majority of submissions were translated papers when the journal was first published, the number of original submissions has exceeded the total number of editions. To appropriately respond to the increase in submissions and contributions from diverse fields of architecture, the Editorial Board was strengthened in 2025. Satoru Takada (Kobe University) will join as AE in the environmental field, and Taishi Watanabe (Waseda University) and Kozo Kadowaki (Meiji University) will join in the design field. Koichi Yasuda (Institute of Science Tokyo) has moved to become an Honorary Editorial Advisory Board Member, and Shin-ichi Tanabe (Waseda University) stepped down from the EIC to concentrate on AE in the environmental engineering field, with Kazuhide Ito (Kyushu University) taking sole charge of the EIC.

Since 2018, JAR has awarded the Best Paper Award to the most outstanding and qualified papers. This year, JAR Editors-in-Chief (EICs) and Associate Editors (AEs) conducted a rigorous and thorough review of the papers published in 2024. We are excited to announce the winners of the 2024 Best Paper Award. All 52 papers published in Volume 7, Issue 1, 2024, were considered for the award. These papers were thoroughly evaluated following the guidelines, and the EICs and AEs decided the winners after considering the following: “high-quality content at an international level,” “exploration of new areas, methodologies, and concepts,” “abundant originality, pioneering achievement, and novelty,” and the “potential and outstanding accuracy, diligence, and effort” of the nominees, along with the review comments for the papers.

Hence, the 2024 Best Paper Award goes to:

Kun-Sian Lin, Masahiro Kurata, Yutaro Kawasaki,

It is expected that unused wells in traditional Japanese houses can be utilized to save energy. In this paper, we examine a hot water supply preheating system that utilizes unused wells in traditional Japanese houses. In this system, the pipe supplying water to the water heater passes through the well water and is preheated by heat exchange with it. We show the results of measuring the well-water temperature in an actual well for a period of 1 year and propose a method for estimating the well-water temperature. Furthermore, we show the results of a heat exchange experiment in the actual well and propose a method for estimating the temperature change of water passing through a coil used for the heat exchange. Finally, using methods of estimating the well-water temperature and the temperature change of water passing through the coil, we estimate the rates of reduction in energy needed to supply hot water via this system when the preheated water supply is heated to 50°C–60°C by this system, as opposed to the case where the unpreheated water supply is heated to 50°C–60°C. These reduction rates are about 7%–17%, depending on the flow rate and the coil length.

This study examines practical layout renovations based on actual living and unit specifications. In Osaka City, significant correlations were found between the number of cohabitants and the apartment layout (R² = 0.50), floor area (0.32), and rent (0.26) for young working households. The pre-renovation unit featured a 2K layout, a 40.5 m² floor area, and a monthly rent of 71 000 yen—specifications that did not align with the typical needs of any household type, potentially leading to vacancies. However, demand was observed in the premium market segment, suggesting that converting to a 1LDK layout could be a viable solution. The estimated monthly rent before renovation was 69 904 yen, while the expected rents after renovation were 72 741 yen (1DK) and 80 917 yen (1LDK). All three renovation proposals received applications, demonstrating the effectiveness of this approach.

This study aimed to reinvestigate one of the main <building I> of the Hellenistic Palace at Pella. A new reconstruction was revealed through new observations of the ruins and detailed analysis of the surviving architectural components. As a result, not only have modifications been made to the previously considered restoration proposals, but it is now clear that the peristyle and north wing underwent at least two distinct construction phases, and that the process of reno. The <building I> was originally a Doric peristyle courtyard. It had a peristyle colonnade space with an even hierarchy overall, although it had a tholos in the north-west and a vestibule and two androns in the north wing. In the later phase, the northern wing was largely altered. Three androns and their antechambers were arranged in three parallel rows, and in front of them was a double Ionic half-column screen. The northern portico was extended by one space of the east–west colonnade of the east–west peristyle, and the remaining foundation was probably converted to the structure of the sculptures display. The tholos on the west side was divided into two apsidal excedrae, and these were placed symmetrically on both side of the north corridor.

This study aims to clarify the current status and issues of outdoor advertisement administration and landscape administration. Three points clarified are shown below. First, if there is an own outdoor advertising ordinance, it is not possible to actively regulate or guide outdoor advertising in the landscape plan. Second, preliminary examination based on the landscape plan of outdoor advertisements by internal adjustment is a non-mandatory request. Third, without the own outdoor advertising regulations, there are obstacles to landscape discussions, such as lack of enforcement and the time required for landscape consultations.