Application properties of ferronickel slag fine aggregate in air-dry condition to high strength concrete was examined by experiment. As a result, it was shown that workability and compressive strength of high strength mortal using ferronickel slag fine aggregate in air-dry condition is similar to that using ordinary andesite crashed sand. In addition, it was possible to make a high strength concrete with good workability using ferronickel slag fine aggregate in air-dry condition.
Using mold specimens according to JASS 5N T-601, and core specimens taken from the walls specimens, experiments investigating the effect some factors, such as the specimen size, water-binder ratio and cement type on the dry density were carried out. Then a testing method for the measuring dry density of shielding concrete was examined by using the core specimens. As a result, by using the core specimens taken from existing concrete structures, the authors could measure the dry density of shielding concrete based on the method of JASS 5N T-601.
The long-time presence of water including chloride in home crawl spaces cause elevated structural degradation after resulting tsunami. In order to clearly the characteristics of chloride penetration on the concrete, experimental study using chloride penetration model was conducted. This paper presents the results of an experimental investigation on the chloride penetration properties of mortar under the water pressure. When the moisture in the concrete is saturated, the penetration of chloride was not affected by the water pressure. However, when the concrete was dry, the depth of chloride penetration became deep with the increase in water pressure.
Cone traces or cones remaining on the surface of the structural concrete may be the penetration path of degradation factors. This study was experimentally investigated to visually grasp the influence of the difference in the type of cones on the penetration of water and carbonation around the cones. The results showed that the penetration of water and carbonation varied depending on the characteristics of the filling material and the adhesion state of the interface between the cone and the specimen.
The conventional injection method for waterproofing the cracks emerging underneath a concrete structure is problematic. Therefore, the authors developed a hybrid type waterproofing using two substances consisting of polyurethane resin and aqueous emulsion. This method reliably stops water leakage by thorough curing. This method performed excellently in testing, demonstrating rapid curability, stability of configuration, the elongation property. It also facilitates the injection of chemicals into fine cracks. In application to a structure, this method was demonstrated excellent durability and performance.
It is reported that exterior materials such as a double-folded plate roof are damaged affected by wind load or thermal load. Particularly, as a double-folded plate roof is used for a long span, their displacements by thermal expansion are large. It is necessary for design and construction to reduce damage in roof joint strength caused by cyclic thermal expansion. This paper shows behavior of a double-folded plate affected by thermal expansion which the building structure were constructed. First, basic data such as temperature and displacement of a double-folded plate roof are investigated. Furthermore, cyclic test of specimen of the double-folded plate roof is conducted and simple analytical model to evaluate lateral displacement of the double-folded plate roof by thermal expansion is proposed.
The demand of wall cray decreased owing to Great Hanshin-Awaji Earthquake or synthetic building material. Therefore, manufacturing plants of wall clay gave up their business in Kagawa. The previous study revealed that the strength of wall clay extracted in Kagawa is higher than other regions. The objective of this study is to examine experimentally the effect of the mix proportion on the strength and workability of wall cray and to rebuild the manufacturing system of wall clay in Kagawa. From the results of various tests, the strength of wall clay is lower, the workability is higher and the cracking area is smaller.
Although partition walls with light-gauge steel (LGS) are damaged by earthquakes in recent years, there are not enough studies to confirm the seismic performance of the LGS walls. In this paper, focusing on the out-of-plane direction of the 65-type LGS wall, we carried out vibration tests and static loading tests by small specimens with various specifications such as the number of plaster boards or connection method of members. Using the results of the tests of each specification, the seismic coefficient corresponding to the strength and response in the real wall size are compared to evaluate their seismic performance.
A downburst simulator has been developed to investigate the characteristics of the velocity distribution and wind loads on buildings induced by downburst. The aim of the project is to propose a reasonable wind resistant design method for downbursts. The simulator consists of a blower that reproduces an impinging flow on the ground and a shatter that reproduces a pulsed jet. The blower can move at a constant speed on rails. It was found that the simulator can reproduce the non-stationary winds by downbursts.
The authors propose a method of the real-time hybrid testing on a building for active mass dampers (AMDs). This method makes it possible to verify both the control performance of AMDs and the stability of AMDs during strong winds that continue for a long period. We conducted a verification test for AMDs by using our proposed method on a 30-story steel building. It was verified that two AMDs were stably controlled at the same time and the vibration amplitude of the 3rd mode that was mainly controlled by these AMDs was effectively reduced.
Since 1995, seismic isolation structures have been applied effectively to buildings whose superstructure is characterized to have a long fundamental period such as steel-framed and high-rise buildings. However, for logistics warehouses which are designed to be long span and a high floor height to create a large internal space, there is a possibility that such buildings will not deform as expected. This study proposes a response prediction formula for base-isolated building by using period ratio between the superstructure and the seismic isolation layer.
Dynamic behaviors of building 70 during a moderate typhoon are reproduced by processing acceleration data acquired by the vibration sensor network in Gunkanjima. Almost half of the ground supporting the building has been lost by erosion and scour in the past severe typhoon. The effects of ground vibration induced by high waves and strong winds on structural responses are investigated. Action of wave and wind on the island changes every moment during a typhoon. It is concluded that different vibrational modes of the building are excited by different load combinations of wave and wind.
We performed at a time history response analysis considering the performance fluctuation of the seismic isolation devices for long-period ground motion. In a building model designed against long-period ground motion to correspond only to conventional notice waves, the maximum response displacement of the base isolation layer exceeds the critical strain depending on the long-period area. However, in the model where oil dampers are added to these models, it has been confirmed that the maximum response displacement of the base isolation layer are reduced by the oil damper.
A series of shaking table tests by using E-defense on a high-rise building are conducted in order to assess effects of retrofit by using oil dampers. The specimen consists of a four-story steel frame and an upper substitute layers made of concrete slabs and rubber bearings. Oil dampers are installed to the steel frame. Long-period ground motions and a design ground motion are used for the tests. Total input energies of the specimen and absorbed energy are estimated. The deformations of specimen are reduced especially in the portion having dampers. In the moment frame, the energy is mostly dissipated in oil dampers.
Subsurface structure model is constructed by simulating dispersion curves usually by GA with reference data such as PS logging. When the reference data is not available or micro-tremor array radius is inadequate for the wavelength of interest, method to infer a simpler subsurface model such as a two-layered model is desirable. We propose the method to deduce surface layer thickness and shear wave velocity of the model by resorting to quarter wavelength theory and the concept of wavelength-thickness ratio. The method itself and the wavelength-thickness ratio is tested by PS logging data at K-NET and KiK-net observation sites.
Free-vibration experiments and static loading experiments were conducted on a 30-year-old base-isolated building in order to evaluate and compare the measured horizontal stiffness of the base-isolation systems obtained from the two experiments. As a result, the horizontal stiffness results obtained from the free vibration experiment showed good agreement with the secant stiffness results obtained from the static loading experiment. This confirms the validity of evaluating the dynamic response of a building seismically isolated by means of natural rubber bearings and steel bar dampers in terms of mechanical properties observed in a static loading test.
Typhoon 1721 occurred on October 16th, going south of Japan from October 21st to 22nd, and around 3 o’clock on 23rd, landed around Shizuoka Omaezaki city. The central pressure of typhoon 1721 at landed was 950 hPa, then the maximum wind speed near the center was 41.2 m/s. In this report, wind speed and direction observation records obtained from an anemometer installed in a truss tower supported steel chimneys are summarized, the dynamic characteristics of the chimneys are evaluated based on the record of the accelerometer, and the results are reported.
In reconstructing the large logistics warehouse with using existing piles, the piles were investigated. The pile diameter and reinforcement arrangement were as designed, and almost all the piles had no crack. The soundness evaluation by the author’s method was equivalent to that of conventional method. The compressive strength was larger than the designed value, and the neutralization depth was smaller than the designed cover thickness. The embedment in the bearing layer was confirmed by the comparison between the core boring through the pile and the standard penetration test. The magnetic exploration was effective on the evaluation of pile length.
This paper proposes reinforcing methods for bolt holes defects in SC grade beams. The strength of SC grade beams decreases by about 30% due to bolt holes defects in column base joint. Two types of reinforcing method are devised: One is reinforcement by L-shaped steels and the other is by channel steels and deformed bars. The availability of proposed methods was confirmed by full-scale tests. The strength of the reinforced SC beams is almost equal to the SC beam without defect. The calculated strength by cross-section analysis agrees with the experimental results well.
This paper first describes the inelastic buckling behavior of three steel truss walls for cyclic in-plane shear deformation. Two of the walls were double-layer diagonal trussed walls and one was single-layer wall without out-of-plane rigidity. Evaluation of buckling and post-buckling strength is the second topic. In each test, significant member buckling was observed but post-buckling strength was stable. The actual buckling length was shorter than the ideal member-axis model due to bending rigidity of joints. It was calculated with a linear buckling analysis modeling the joint.
The authors designed and constructed two types of tensegrity structure, tower tensegrity and truncated pentagonal prism tensegrity, as a structural skeleton to support a membrane roof. In the Part 1, the progress of design and manual pretensioning scheme of the tower tensegrity, and results of practical performance tests of manual pretensioning in a laboratory were reported. In the Part 2, the state and result of pretensioning of the tower tensegrity during the actual construction is reported and compared to the predicted behavior in the design stage.
In this report, we carried out examination to estimate the earthquake maximum response of the real-scale timber case study house with mud wall. The examination intends for an observed acceleration response wave pattern (Tohoku Region Pacific Coast Earthquake March, 2011) by a strong-motion seismograph installed in an experiment house. P-Δ curve of the experiment house was made based on technique of the previous announcement. In addition, a reply spectrum at the 2nd-floor level was got from an observation wave in the ground level. This result accorded with the damage situation in the element experiment of the mud wall.
This paper reports a development of long-term stiffness reduction control method of timber lattice shear wall due to shrinkage by introducing compressed wooden wedge into the joint. The effectiveness of the developed method based on size recovery property of compressed wooden wedge was revealed by the long-term test. Also material test and joint test confirmed the phenomenon. The shear wall index of developed wall after 1 year showed 0.97 which was smaller than idealistic value of the wall with no gap but sufficiently higher than the realistic value of normal lattice shear wall obtained by the test.
A seismic strengthening method for seismically vulnerable existing wooden houses using corrugated steel cladding plates covering the mortar exterior finish was proposed and the performance was evaluated in experiments and numerical simulations. The primary failure mode of strengthened shear walls in the experiments was yielding of the screws. Simulation models of the walls were created using inelastic shear springs for the screw connections. The behavior of the strengthened frames under static lateral forces were simulated. It was found that the spandrel walls contribute to the lateral strength significantly and the method improves the strength of both walls and connections between the wooden members.
This report presents studies on the construction performance of connecting buckling restrained braces in RC frames and the decrease in the tension of anchor PC rods. First, a construction test considering actual building conditions was carried out. From the test result, problems in actual construction were identified and the possible solutions were examined. In addition, long-term measurement of the tension in the anchor PC steel rods was conducted for one year. From the results of the long-term measurement, the decrease in the tension of PC rods was analyzed, and the method for designing anchor PC rods was suggested.
Behaviors of reinforced concrete slabs demolded at the early age in October and subjected to sustained bending moments are investigated through eight specimens. The test parameters are (1) the age at demolding (three or twenty-eight days), (2) the magnitude of the bending moments (zero, 0.3Mc, or 0.6Mc, where Mc is the computed cracking moment), and (3) the directions of loading (in tension or compression on the top fiber). The test results show the effects of the age at demolding are ±20〜30% on the time-dependent curvature increase.
This paper verified the seismic performance of low-rise reinforced concrete buildings in metropolitan area, designed by Lateral Load Carrying Capacity. The validation target is rigid frame structures and boxed wall structures. In the verification, profile of the grounds and interaction between the ground and structure are considered. The paper concludes that the response of the buildings is significantly affected by the ground profiles, height of the buildings and deformability of the buildings. Finally, the paper indicates the map showing their risk index based on the relationship between their deformability of buildings and response drift angle.
In-line continuous high-panelized shear walls containing steel sheets with vertically aligned burring holes with at least one vertical slit every 0.91-m-wide are employed in buildings in seismically active regions. The purpose of this study is to clarify the shear resistance mechanisms of the walls with and without vertical slits. The wall that receives the shear force allows shear stress to concentrate in the intervals between the holes. All intervals between the holes were simultaneously deformed and the buckling areas were restricted by the use of ring-shaped burring ribs. The post-buckling behavior was dependent on the shapes of the tension field. The effect of vertical slits involved maintaining wall strength stable in the inelastic region. The formulas of the allowable design strength and the indexes of ultimate state strength after shear buckling were developed.
The reuse system proposed by authors based on past studies is one of methods to reduce environmental burden in the structural field. Recommendation for sustainable steel building construction(Draft) by Architectural institute of Japan published in which design and supervision flow is shown. In this paper, design and supervision flow for member reuse is verified by building steel structure. First, procedure of member reuse based on design and supervision flow is shown. Investigation before dismantling such as evaluation quality, design, investigation after dismantling such as re-evaluation quality, construction, information management of the building steel structure are shown. In this flow, environmental evaluation is also conducted.
In Japan, early models of light-gauge steel prefabricated houses were developed in 1960’s. This study aims to investigate the structural properties of those two models: one is “style-A” and the other is “style-B” which is an improved version of style-A. A series of on-site survey was carried out to measure the dimensions of structural frames and the obtained information was summarized as structural drawings. An elastic structural analysis was carried out to compute stresses, deflections and story drifts in structural frames subject to the design loads, and the structural property of each model was discussed.
Coupon tension tests using steel plate specimens with full thickness more than width were conducted to obtain the relation between uniform elongation and rupture elongation. Two types of steel materials (SA440, H-SA700) were selected and three types of coupon tension specimen (JIS No.1A, No.5, and No.12A) were used for the tests. After showing characteristic results of thick specimens, the applicability of a prediction formula for the relation proposed by the authors is investigated. It is clarified that the rupture elongation values obtained from the proposed formula are almost equal to or larger than those of the corresponding test results.
This paper presents data obtained from experiments on an historical brick building. Two kinds of experiments were conducted. First, an out-of-plane bending test of the brick wall, and second, a material test for brick with lime plaster joints. The following information is obtained: (1) Valuable material test data of the lime plaster joints. (2) For a simple supported brick wall specimen, serious strength deterioration occurs from cracks in lime joints. However, brick walls reinforced by aramid fiber or SRF sheet do not show serious strength deterioration. (3) The fixed wall specimen has high strength due to arch action.
Usually, headed studs are vertically welded in a steel surface. However, we think that composite beam using inclined headed studs improves shear stiffness and strength. In this paper, we investigated the mechanical property of connection using inclined headed studs through the test under cyclic shear load. It was found from the test results that positively inclined headed studs have higher shear stiffness and strength. And, we proposed appropriate arrangement and the direction of inclined headed stud for each of the beam and the girder. Moreover, we proposed the evaluation method of ultimate shear strength of connection using inclined headed studs.
To predict the earthquake damage, we have constructed database of the super high-rise buildings in Osaka prefecture and identified the fundamental period of 32 super high-rise buildings by micro-tremor measurements. More than 20% of the super high-rise buildings are base-isolated, and more than 80% of the base-isolated buildings are condominium. The largest proportion of the building use was office before 2000. However, the construction of condominium has increased since 2001. After the 1995 Hyogo-ken Nambu earthquake the fundamental natural period has been short in Osaka. The fundamental natural period was about 1.1 to 1.3 times to that at the completion.
Daylighting film is newly invented material for window. When daylighting from the sky come through this film on vertical window, it is refracted up to indoor ceiling. Although it is quite effective to guide daylight, appropriate way to affix it on a window should be different depending on the condition of the window. For southern window, it is not adequate to cover whole window with daylighting film because of several factors such as view and privacy. Thus, partially affixing of daylighting film on southern window is proposed, and subjective effects of several settings were studied.
This report describes the results of site inspection of child daycare facilities and interview with the related persons regarding with acoustic design, which were carried out in Munich city region, Germany, where regulations of acoustic design for daycare facilities exist. The purpose of this attempt is to find the situation of acoustic design in daycare facilities in contrast to those in Japan without any standards or regulations. The result revealed that all the rooms in the inspected facilities were equipped with sound absorptive material and personnel were more or less aware of the benefit of good acoustics.
Article 30 of the Building Standards Act stipulates that “the partitioning walls of each unit must reach the attic space or ceiling space”. For the purpose of validating the above stipulation in Article 30, this paper reports the results of the investigation which was made based upon the use of a real building to examine the impact that the existence of partitioning walls in attic spaces and possible changes in specifications of attic spaces may have on sound insulation properties of the wall between neighboring units.
The purpose of this research is to estimate the characteristics of the installed resonance according to the sectional specification of the floor finishing material. First of all, as a fundamental study for that purpose, in this report, we focused on the difference in level between the floor finish material and the floor structure surface, including the investigation of resonance by installing the vibration pickup. The items to be investigated are vibration source, floor structure, etc. As a result, the increase / decrease amount of the floor finish material and the floor structure surface was clarified for each study item.
A lighting social experiment was conducted to create continuous and inherent streetscape including open spaces caused by the earthquake disaster, to visualize evacuation routes at night and to restore the appearance of Youkamachi in Kesennuma City. As a result of the experiment, it was found that the expected functions and energy saving could be realized by dispersing the light sources in the buildings, open spaces, and evacuation routes. Such lighting methods were considered to contribute to producing streetscapes that would exist in the future while respecting the structure of the city left after the disaster.
The site attenuations and propagation distance of radio wave intensity with 920 MHz band wireless sensors in one building (office and conference room) were clarified by measuring. In the case of -70 dBm with lower limit of radio wave intensity, the propagation distances of the office and conference room are 6.4 m and 7.3 m, respectively. It is clear that the propagation distance becomes shorter due to partitions and humans. Moreover, we could simulate the measurement result using ray tracing method, which is shown that the method is effective to predict the spatial distribution of radio wave intensity.
In recent years, CLT (Cross Laminated Timber) has attracted attention as domestic forestry revitalization and reduction of LCCO2 of buildings are required. Hokkaido Larch accounts for 30% of the planted forests in Hokkaido. For that reason, CLT buildings using Hokkaido Larch are important for the utilization of forest resources and reduction of LCCO2 in Hokkaido. In this report, we report on the result of examining the thermal performance which has a big influence on energy reduction during operation.
This report introduces the design of a Net Zero Energy House in the suburban Tokyo and the evaluation result of the thermal environment and the energy consumption of it. Highly insulated and air-tight envelope, passive solar gain, sun-shading, daylighting and natural ventilation, thermal mass, highly efficient equipment and photovoltaic panels are applied to this house. In the design phase, the energy consumption and the amount of power generation was simulated. In the first year after construction, the actual amount of them was estimated by HEMS data, and it closely matched the evaluation in the design phase.
The hand book for architectural design issued by Architectural Institute of Japan is based on the experience of practical work or research achievement and updated toward changing of technology or demand. However, the update is becoming difficult because the most of contents are paper-based and required contents are increasing. Then we propose the digital hand book for architectural design by using Building Information Modeling (BIM) to integrate building dimension and information. This paper presents one of the example edition for mechanical design focusing on the calculation of office building heat load.
Efforts of local governments are essential for achieving the Sustainable Development Goals (SDGs), core elements of the 2030 agenda adopted by the United Nations in September 2015. A nationwide online questionnaire survey was conducted to collect data on the actual implementation level of the SDGs in Japan. Results showed that about 30-40% of local governments is considering/developing a plan and implementing projects towards achievement of the SDGs in Japan.
The report aimed to clarify issues on utilization of building LCA in Japan and discuss ways to deal with them. First, over 300 Japanese and international papers related to LCA were reviewed and showed that, while many international studies adopted multiple criteria for impact assessment; almost all Japanese papers discussed LCA based only on analyses of energy consumption and CO2 emission. Subsequently, a questionnaire survey was conducted with building LCA practitioners in Japan as respondents; which revealed that their purposes of assessments varied widely. The survey also clarified a number of key issues, such as guideline, inventory database, and software.
In this study, a questionnaire survey was conducted to assess the status of air purifier and humidifier installation at kindergartens and nurseries in the Hokuriku region as countermeasure against influenza. In this region, 64% of the facilities, lower than that in the Tokai region, installed at least one equipment affecting the indoor air environment. The proportion of the installation of these equipment was higher at nurseries than at kindergartens. Window opening ventilation was the most widely adopted preventive measure against infection, and the use of air purifiers and humidifiers may influence the indoor environment only slightly.
In recent years, China cities are carrying out comprehensive renovation projects for old apartment complex. This study analyzed the project content and implementation methods, reached the following conclusions. 1)The project focus has altered from the renovation of the community environment to solve the problem of aging and community management issues. 2)The organizational form, content of implementation and the clear financial system together promoted the project. 3)Although the project improves the living environment, it also reduces the freedom of space use. In addition, the various levels of self-management should be taken seriously.
The study intended to clarify Chinese urban elders' key concerns toward elderly care institutions as well as their differences in thoughts through questionnaire survey in Shanghai. The result suggested a general positive attitude toward institutional care, and elders valued quality of care, medical convenience, hardware condition and economic cost mostly when choosing facilities. Besides, merits and demerits of institutional care raised by elders indicated their differences in prior concern: benefit of the whole family, individual feeling, material environment or social atmosphere. It was also found that elders’ considerations were significant influenced by their gender, education level and health status.
Cooperative-Style group home is expected to provide a synergistic kind of care to elderly with dementia and people with disability who live together. They have access to shared common space and equipment (i.e. entrances, bathrooms, toilets). These group homes are the first of their kind practicing the pioneering framework from conventional homes. The aim of this paper is to contribute to the body of knowledge about of Cooperative-Style Group Homes by proxemic behavioral analysis, specially the interpretation of the movement patterns of residents, and to offer the knowledge about common space composition, construction and the facilities plan.
This study proposes a re-organizing planning method of the facility for the elderly by simulation of optimizing capacity and demand in a local city and discusses on matters of it. We estimated the number of bed demand based on the future estimation of senior population, judged the excess or deficiency of the capacity of the existing facilities, and examined the facilities whether they should be re-organized. As a result, we could estimate the number of bed demand precisely based on the over 75 years old people population, but in some case, we need more precise data of user ratio per population over 75 years. And it is also a matter how to deal inpatient who will be enrolled facilities at other cities and who will come from other cities.