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In the evaluation of concrete sustainability, what constitutes "sustainable" to one region may vary from another. This often leads to methodological forms of uncertainties that makes the evaluation process more complex. As such, this paper aims to quantify the effect of uncertainties in the regional context on the sustainability evaluation of concrete materials. This is carried out by quantifying the regional context through establishing a weighting scheme and then integrating the obtained weights into the sustainability analysis of concrete materials in tandem with uncertainty analysis. Japan is used as a case study because although it relatively appears as a homogeneous country, its prefectures possess unique characteristics that may make the sustainability evaluation of concrete materials vary across prefectures. Cluster analysis is carried out in the 47 prefectures of Japan using a set of regional context indicators. Five clusters are identified with varying characteristics and these are translated into different weighting schemes. The established weights are used in the sustainability evaluation of concrete materials using multi-criteria decision-making analysis. The results showed that one mix is the most sustainable for four of the clusters and a different mix is the most sustainable for the remaining cluster. When uncertainty analysis is conducted, the effect of the weights in the sustainability evaluation is explained by examining the average scores of the concrete mixes and the variance of the scores across the five clusters. This investigation facilitated the understanding of how regional differences and the uncertainties associated with it impact the evaluation of concrete sustainability. [ABSTRACT FROM AUTHOR]

This paper presents a critical review of the main research progress and application of Shirasu concretes in Japan recently. As a kind of pyroclastic-flow deposits, Shirasu aggregate was considered as one kind of nonstandard aggregates for modern concrete industries because it usually has a low density and a high water content rate, and also contains a large amount of fine powder on its surface. However, with the considerations that Shirasu has a high level of pozzolanic activity and can be available widely and easily in Japan, many studies had been performed in Japan in the last two decades. The key concerns in the paper focus on the basic fresh properties of Shirasu raw material, the mix design, and the basic material properties of Shirasu concretes. Based on this review, several recommendations were provided for future works. Through the review, Shirasu concrete considered as a construction material could present accepted material properties compared with traditional concrete, including basic fresh and mechanical, and durability properties. It was suggested to apply concrete structures with careful concerns and recommended to structures under several special environments. Using this aggregate, several kinds of high-performance concrete also could be produced. [ABSTRACT FROM AUTHOR]

This paper describes the development and present status of seismic evaluation and seismic retrofit of existing buildings mainly for low-rise and medium-rise reinforced concrete buildings in Japan. First, since the seismic evaluation of existing buildings has close relationships with the seismic design of new buildings, a brief history of the development of seismic design, seismic evaluation, and seismic retrofit is provided in terms of major earthquake disasters mostly in Japan and associated with some major events in the U.S. Then, the development of seismic evaluation and retrofit is reviewed, focusing on the items in which the author has been deeply involved. This provides insight into previous earthquake damage, methodologies for seismic evaluation, the basic concept of the Standard for Seismic Evaluation of Existing Reinforced Concrete Buildings, studies on the demand criteria for seismic safety, and the present status of seismic evaluation and retrofit. Finally, the typical methods of seismic retrofit and some examples of retrofitted buildings in Japan are explained.

Geofoam has the scientific name of expanded polystyrene (EPS). A block of EPS is made from particles of polystyrene through an expanding and melting process in an automatic mold machine by adding steam. The geofoam construction method employs large EPS blocks with unit weights between 12 and 30 kgforce/m3. In the 1970s, the use of EPS as a lightweight embankment in highway and earthwork developed concurrently in the United States and Norway. Most notably, in 1972, the Norwegian Road Research Laboratory placed geofoam in the approach fill of the Flom Bridge. The advantages of this construction method are that geofoam can be used not only to replace ground fill material but also to reduce the load applied to the foundation. This paper will introduce the following topics related to geofoam: the background and inspection conditions in Taiwan, United States, and Japan, the quality investigation of EPS production, and the experimental and analysis results of EPS manufacturing quality and homogenous test. This research illustrated that the quality control chart can analyze the stability of manufactured EPS. Meanwhile, the homogeneous testing method, which is put forth in this paper, can actually examine the stability of EPS manufacturing procedure. The results of this study can be used as the reference for quality control of geofoam. The issue of geofoam used for collision prevention, self-weight decreasing, and landslide resistance in geotechnical engineering will also be discussed. [ABSTRACT FROM AUTHOR]

Building materials, such as brick and concrete, are known indoor radon (222Rn) and thoron (220Rn) sources. Most radon and thoron exhalation studies are based on the laboratory testing of pieces and blocks of such materials. To discuss if laboratory findings can be applied to a real-world environment, we conducted intensive in situ exhalation tests on two solid concrete interior walls of an apartment in Japan for over a year. Exhalation rates of radon (JRn) and thoron (JTn) were measured using an accumulation chamber and dedicated monitors, alongside monitoring indoor air temperature (T) and absolute humidity (AHin). There were weak correlations between JRn or JTn and T or AHin at one tested wall, and moderate correlations of JRn and strong correlations of JTn with T or AHin at the other wall, meaning more or less seasonal variations. The findings aligned with previous laboratory experiments on JRn but lacked corresponding data for JTn. Additionally, a moderate or strong correlation between JRn and JTn was observed for both tested walls. Comparison with theoretical calculations revealed a new issue regarding the impact of each process of emanation and migration within concrete pores on radon and thoron exhalation. Overall, this study provides insight into parameterizing radon and thoron source inputs in modeling the spatiotemporal dynamics of indoor radon and thoron. [ABSTRACT FROM AUTHOR]

This paper describes ultra low-level gamma-ray spectrometry measurements of the (60)Co activity distribution inside one 52 mm and one 41 mm thick steel sample. The samples had been exposed to the Hiroshima atomic bomb and were from the Aioi bridge and the Yokogawa bridge. Both samples were measured in a recent study aiming to back up model calculation of Hiroshima dosimetry. The (60)Co activity distributions found in this study support the assumptions made in the previous study., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

For all countries analyzed so far, Material Flow Analysis/Accounting (MFA) studies indicate that the overall stock of materials within the economy is growing. Most are construction minerals such as asphalt, cement, sand and gravel, crushed stone, and other aggregates. In the analyses described in this paper, flows and stocks of construction minerals were estimated for Japan from the past to the future to elucidate: (1) the mechanisms by which construction minerals become waste, and (2) the future supply of and demand for recycled crushed stone. The following conclusions were drawn: (1) The amounts of waste construction minerals generated have been and will be at much lower levels than the domestic demand for construction minerals. These differences might indicate consistent growth of the stock of construction minerals, which will become waste in the future. However, certain amounts of materials that we account for as stock can be interpreted already in the environment as dead stock or dissipated waste; such materials can be called "missing stock" or "dissipated stock". Capturing that missing or dissipated stock is very important because it provides information that clarifies the environmental impacts and loss of resources that these materials cause; it allows estimation of appropriate future waste generation. (2) The amount of construction minerals that are recognized as waste was estimated to increase in the future. An imbalance in the supply of and demand for recycled crushed stone will likely occur in the near future if an expected decline in future road construction is considered.

A potential alternative of sewage sludge reuse is the substitute of raw material for Portland cement. This paper overviews Japanese implementation of this and discusses the best selection of pretreatment for this purpose. The pretreatment includes dewatering, incineration, and lime treatment.

Indoor radon and thoron concentrations were dominated with their exhalation rate from building materials. Thus, the evaluation of exhalation rate with highly precise is important. This paper presented a new technique to measure the dependence radon/thoron exhalation rate, from building materials used in Japan, on absolute humidity. The measurement technique consisted of a solid state alpha detector equipped a ventilation-type chamber and humidity control system in a flow through method. The exhalation rate of dried samples (Indian red granite and Japanese gray granite) was measured at various absolute humidity levels in the range of 1-20 g cm. It was found that exhalation rate increased exponential with increasing of absolute humidity for both samples. Furthermore, the dependence of radon emanation coefficient on building material's temperature was also studied using an accumulation chamber equipped with scintillation cell alpha detector. The emanation coefficient of dry sample increased proportionally with increasing the material's temperature with a correlation factor of 0.88. [ABSTRACT FROM AUTHOR]

“Tatami” is a traditional Japanese building material used as a floor mat made with rush. It used to be said that the smell of tatami is preferred by many Japanese, because almost all Japanese houses have had tatami rooms since early times. In this paper, the psychological bias of notification of material name was investigated. This kind of psychological bias seems to be a very important factor that affects the result of sensory test. In the sensory evaluation of odor, the name of the source material is usually concealed, but in this paper, odor evaluation tests were conducted where the source material name is given to the subjects before its evaluation. The usual test that the source material name is not given was also conducted using the same panels. The odors emitted from three building materials that included white cedar, tatami and concrete were selected. Odor intensity, impressions, hedonics and acceptability were voted by eight young subjects. As expected, the tatami odor evaluation results indicated that the odor acceptability rose when the subjects were notified of the material name before evaluation. The acceptability of the concrete odor tended to drop conversely when the material name was given beforehand. In addition to above investigations, another series of tests were conducted where the fake name was told to the panels before testing using odor from tatami and concrete. The fake names were garbage instead of tatami and cypress instead of concrete. It was turned out that the preference of the material has quite a large effect on the odor evaluation results. [Copyright &y& Elsevier]

Over the last 30 years in Japan, there has been a 10% increase in the number of people suffering from sick house syndrome due to toxic chemicals released from construction materials and wallpaper. This syndrome can develop into the more complex and disabling, chemical sensitivity syndrome, so preventing early exposure to toxins at home is critical in reducing the likelihood of health problems in the community. A qualitative study was undertaken using ethnographic methods to identify the psychosocial aggravating factors of sick house syndrome. As a result, the participants identified three aggravating factors that extended the period of exposure of the participant to toxic chemicals: a lack of knowledge about the disorder; the difficulty in establishing a diagnosis; and the difficulty of taking radical measures to improve the home environment. Public awareness of sick house syndrome and the dangers of toxicity from construction materials is vital to eliminate these aggravating factors and to prevent illness. [ABSTRACT FROM AUTHOR]

Japan has twenty years of experience in designing and constructing base-isolated building structures. Construction has increased significantly since the 1995 Hyogoken-Nanbu (Kobe) earthquake, having reached over 150 annual construction projects. Many new developments and refinements have been made in the material, device, design, and construction of these structures. This paper summarises recent design and construction of base-isolated building structures in Japan, including statistical data with respect to the common usage as well as the number of new projects. It is notable that the size, height, and fundamental natural period of new base-isolated buildings increase steadily with time, indicating that base-isolation in Japan is reaching maturity. Base-isolators and dampers commonly adopted in Japan are also introduced, with emphasis on recent design efforts to enlarge the natural period of base-isolated structures and reduce the lateral forces induced in the superstructure. Basic design procedures are presented, including determination of design earthquake forces, modelling of base-isolation layers, modelling of the superstructure, selection of ground motions, time-history analyses, and performance criteria. A mandated peer-review system, unique for design of base-isolated structures, is also noted. Several characteristic issues in the design of base-isolated structures are discussed: Variation of base-isolation material properties, applications to high-rise buildings, effects of vertical ground motions, and response when subjected to near-fault ground motions. [ABSTRACT FROM AUTHOR]

In recent years, wood has been considered as a building material from the perspective of SDGs. Pre-cut lumber is often used for wooden houses, including roofs, floors, and pillars. It is preprocessed into a certain shape for the joint parts and has joint brackets if necessary. The use of them has the advantages of shortening the construction period and reducing the construction cost. The number of pre-cut lumber production factories in Japan decreased from 757 in 2001 to 659 in 2011 and then increased to 730 in 2016. Compared with 2011, the number of factories with sales of <500 million yen in 2016 decreased by approximately 30%, while the number of factors with sales of ≥500 million yen increased by 80%, indicating a trend toward a larger scale [1]. Therefore, improving the productivity of these factories is imperative. We have been researching the conversion of factories into smart factories to improve the productivity of pre-cut lumber manufacturing company A. In this company, employees take 1.2 h to prepare packing plans every day, and the company faces the challenge of improving the efficiency of planning operations. Herein, we propose an algorithm using an iterative local search (ILS) with Or-opt (ILS + Or-opt) for packing formation support systems to improve the efficiency of planning operations. This algorithm has the following two features. First, it uses Or-opt to create a neighborhood for a local search. Second, uses exchange neighborhoods when repeating the ILS to achieve diversity in the search. [ABSTRACT FROM AUTHOR]

Abstract: Recently, several research and development (R&D) programs of beryllium and its alloys for fusion reactor application have been conducted in Japan and the community of beryllium research has grown. In the R&D area of beryllium technology for a solid breeding blanket, a major subject is applications of beryllides, for which lifetime evaluation as neutron multiplier, impurity effect on irradiation behavior and recycling of irradiated materials are under investigation. As for neutron multiplier materials, recent R&D has focused on Be–Ti alloys based on Be12Ti as an advanced option, because of their superior properties compared with beryllium metal in such respects as compatibility with structural materials and oxidation resistance at higher temperatures. In this paper, recent results on beryllide R&D in Japan are described. [Copyright &y& Elsevier]

Architects' perennial discussions on the walls of the Japanese house started in the early twentieth century, when calls for the rationalization and modernization of people's everyday lives became the impetus for their engagement in housing design. One of their solutions to this sociocultural issue was the introduction of western prefabricated wall construction, structurally contrasting with the conventional post-and-beam construction. This architectonic approach to modernizing Japanese life and dwelling was further activated by modernism, and oriented toward the standardization and industrialization of housing. This essay focuses particularly on the interwar years, when some modernist architects, including Tsuchiura Kameki, designed prefabricated houses using timber rather than steel. We explore their experimental attempts to discover the heretofore unexperienced features and meanings of panelized walls and materials, as well as the relationship between construction and architectural production. Their progressionist vision, predicting the future shift of building materials and methods, cognitively affected postwar home industrialization. [ABSTRACT FROM AUTHOR]

Concrete is the most widely used construction material in the world. In particular, cementitious composites that contain reinforced fibers have a relatively large amount of cement. Therefore, in this study, the target is to maintain at least 90% of the performance along with a reduction of CO2 emissions from the material stage during fiber-reinforced cementitious composites (FRCCs) production by applying fly ash (FA) and recycled sand (RS). To calculate the amount of CO2 emission at the stage of manufacturing the FRCCs, life cycle inventory database (LCI DB) were referenced from domestic and Japan. As the performance efficiency indicators, simple equations to evaluate the amount of CO2 emission of FRCCs were then formulated as a function of the replacement ratio of FA and RS. And binder and CO2 intensities were analyzed by FRCCs strength. Based on the results for the test, a mix of FA 25% and RS 25% of W/B 0.45, is considered most suitable in terms of performance of FRCCs and reduction of CO2 emissions. [ABSTRACT FROM AUTHOR]

The spatial distribution of ambient gamma dose rates in a high-rise steel-reinforced concrete building in Fukushima, Japan, was examined relative to the gamma-ray emissions from building materials and radionuclides derived from the 2011 nuclear accident. The results revealed the minor role of accident-derived radionuclides in ambient gamma dose rates ~7 y after the accident. The ambient gamma dose rates were higher in the upper floors because of gamma-ray emissions from natural radionuclides in the floor slabs. The fractional contribution of natural radionuclides to the ambient gamma dose rates indicated compositional differences in concrete between the upper- and lower-floor slabs. [ABSTRACT FROM AUTHOR]

Urban heat islands (UHI) are growing in size and intensity, which is partly attributable to the large amount of anthropogenic waste heat. Moreover, heat emitted from building exterior walls accounts for a large portion of the total anthropogenic waste heat. Thus, strategies and technologies for preventing the emission of heat from building exterior walls are being pursued by researchers worldwide. Amongst these technologies, the potential of use of retro-reflective (RR) materials instead of diffuse highly reflective (HR) materials applied to building envelopes for UHI mitigation is being studied widely. However, RR materials haven't been applied to building envelopes in practice due to their unproven weather resistance. In order to develop RR materials with high weather resistance for application to building envelopes, two types of micro glass beads with different refractive indices (1.5, 1.9) and five different colors of base layers were evaluated in this study. Their RR performance was measured by optical experiment and compared to two types of RR sheets commercially available in Japan. The results showed that the glass bead RR samples with a refractive index of 1.9 had much higher retro-reflectivity (better RR capacity) compared to those with a refractive index of 1.5. [ABSTRACT FROM AUTHOR]

After several tsunami events with disastrous consequences around the world, coastal countries have realized the need to be prepared to minimize human mortality and damage to coastal infrastructures, livelihoods and resources. The international scientific community is striving to develop and validate methodologies for tsunami hazard and vulnerability and risk assessments. The vulnerability of coastal communities is usually assessed through the definition of sets of indicators based on previous literature and/or post-tsunami reports, as well as on the available data for the study site. The aim of this work is to validate, in light of past tsunami events, the indicators currently proposed by the scientific community to measure human vulnerability, to improve their definition and selection as well as to analyse their validity for different country development profiles. The events analysed are the 2011 Great Tohoku tsunami, the 2010 Chilean tsunami, the 2009 Samoan tsunami and the 2004 Indian Ocean tsunami. The results obtained highlight the need for considering both permanent and temporal human exposure, the former requiring some hazard numerical modelling, while the latter is related to site-specific livelihoods, cultural traditions and gender roles. The most vulnerable age groups are the elderly and children, the former having much higher mortality rates. Female mortality is not always higher than male mortality and not always related to dependency issues. Higher numbers of disabled people do not always translate into higher numbers of victims. Besides, it is clear that mortality is not only related to the characteristics of the population but also of the buildings. A high correlation has been found between the affected buildings and the number of victims, being very high for completely damaged buildings. Distance to the sea, building materials and expected water depths are important determining factors regarding the type of damage to buildings. [ABSTRACT FROM AUTHOR]

This article describes research conducted for the Japanese government in the wake of the magnitude 9.0 earthquake and tsunami that struck eastern Japan on March 11, 2011. In this study, material stock analysis (MSA) is used to examine the losses of building and infrastructure materials after this disaster. Estimates of the magnitude of material stock that has lost its social function as a result of a disaster can indicate the quantities required for reconstruction, help garner a better understanding of the volumes of waste flows generated by that disaster, and also help in the course of policy deliberations in the recovery of disaster-stricken areas. Calculations of the lost building and road materials in the five prefectures most affected were undertaken. Analysis in this study is based on the use of geographical information systems (GIS) databases and statistics; it aims to (1) describe in spatial terms what construction materials were lost, (2) estimate the amount of infrastructure material needed to rehabilitate disaster areas, and (3) indicate the amount of lost material stock that should be taken into consideration during government policy deliberations. Our analysis concludes that the material stock losses of buildings and road infrastructure are 31.8 and 2.1 million tonnes, respectively. This research approach and the use of spatial MSA can be useful for urban planners and may also convey more appropriate information about disposal based on the work of municipalities in disaster-afflicted areas. [ABSTRACT FROM AUTHOR]

A huge amount of construction material is required in urban areas for developing and maintaining buildings and infrastructure. Ageing stocks, which were built during a period of rapid growth in Japan (1955-1973), will cause a new waste flow in the near future. In order to assess urban metabolism with regard to building and infrastructure, it is necessary to understand change in its material accumulation both 'spatially' and 'temporally'. In this analysis, material accumulation over time is elucidated using four-dimensional Geographical Information Systems (4d-GIS) data at an urban scale. An approximately 8 km2 urban area of Salford in Manchester, UK, and 11 km2 of Wakayama City centre, Japan, were selected as case study sites. In this analysis, the material stock of buildings, roadways and railways was estimated locally over time, using a 4d-GIS database: (1) to find the spatial distribution of construction materials over time, (2) to estimate the demolition curve of buildings based on characteristics of an area, and (3) to clarify material accumulation with vertical location, such as above and below ground, from the viewpoint of recyclability. By estimation of the demolition curve, the life span of buildings in an urban area was found to be shorter than the national average respectively at both sites: 81 years in the urban area of Salford compared with 128 years for the UK; and 28 years in Wakayama City centre compared with the Japanese national average of 40 years. In 2004, 47% of total construction material was stocked in underground infrastructure in Wakayama City centre. Une quantite considerable de materiaux de construction est necessaire dans les zones urbaines pour construire et entretenir les batiments et les infrastructures. Les parcs batis vieillissants, qui ont ete construits au cours d'une periode de croissance rapide au Japon (1955-1973) occasionneront un nouveau flux de dechets dans un proche avenir. Afin d'evaluer le metabolisme urbain du point de vue des batiments et des infrastructures, il est necessaire de comprendre a la fois dans l'espace et dans le temps les changements intervenant dans son accumulation de materiaux. Dans cette analyse, l'accumulation de materiaux au fil du temps est elucidee en utilisant les donnees de Systemes d'Information Geographique quadridimensionnels (SIG-4D) a une echelle urbaine. Un secteur urbain d'environ 8 km2 de Salford, a Manchester, au Royaume-Uni, et 11 km2 du centre-ville de Wakayama, au Japon, ont ete selectionnes comme sites pour cette etude de cas. Dans cette analyse, le parc de materiaux constitue par les batiments, les routes et les voies ferrees a ete estime localement au fil du temps, en utilisant une base de donnees SIG-4D: (1) pour decouvrir la distribution spatiale des materiaux de construction au fil du temps, (2) pour estimer la courbe de demolition des batiments en se basant sur les caracteristiques d'un secteur, et (3) pour clarifier l'accumulation de materiaux par leur emplacement vertical, tel qu'au-dessus et en dessous du sol, du point de vue de la recyclabilite. Grace a l'estimation de la courbe de demolition, il a ete decouvert que la duree de vie des batiments dans un secteur urbain est inferieure a la moyenne nationale sur les deux sites, respectivement: 81 ans dans le secteur urbain de Salford, compare a 128 ans pour le Royaume-Uni; et 28 ans dans le centre-ville de Wakayama, compare a la moyenne nationale japonaise de 40 ans. En 2004, 47% de la totalite des materiaux de construction, dans le centre-ville de Wakayama, etaient accumules dans les infrastructures souterraines. Mots cles: parc bati, Systemes d'Information Geographique quadridimensionnels (SIG-4D), parc des infrastructures, flux de masse, intensite en materiaux, analyse du parc de materiaux, developpement durable, temps, flux de masse urbaine [ABSTRACT FROM AUTHOR]

Bricks of tunnels and bridges of Usui Pass railway (Japan) exposed to north are subject to frost damage. Average depth of erosion due to detachment of angular blocks is around 1-1.5 cm. In order to assess this weathering and to understand its mechanism, an experimental study was carried out in the field and laboratory. Field monitoring showed the combination of seasonal and diurnal freezing with a maximum of heave when the freezing front reached 5 cm depth. Bricks taken from the site were submitted to unidirectional freezing at capillary and vacuum saturation in the laboratory. Results showed that frost damage of bricks was favoured by high saturation level and repetition of freeze-thaw cycles. [ABSTRACT FROM AUTHOR]