According to the investigation of recent research thesis, this paper describes the compensation vale of compressive strength of concrete using fly ash. As the result, in case of fly ash cement (type-B), the compensation vale of compressive strength can apply the standard value of JASS5 on the safe side and the compensation vale of concrete with hot weather can be reduced from 6N/mm2 to 3N/mm2. In case of fly ash cement (type-C), the compensation vale of compressive strength should use the standard value of fly ash cement (type-B) of JASS5 as a reference value.
In this research, in order to show the basic properties of Light Weight Cement Mortar used for Blending Lath Mortar including early material age, and with the implementation of related mechanical properties evaluation test, a simple test method was proposed and attempted to evaluate the occurrence characteristics of dry shrinkage cracks of early material age. The results show that the fundamental characteristics can be demonstrated by the compressive strength, crack tensile strength and flexural strength of the test specimen centering on the early material age.
Changes in the shielding performance of shielding containers made using heavy-weight concrete with high shielding capability against radioactivity for interim storage facilities were investigated by outdoor exposure, particularly when in contact with external water. As a result, no marked difference was found in the ratios of micropores near the surface after outdoor exposure. Water permeation tests to evaluate their shielding properties revealed that their shielding performance was equivalent to that before exposure. Within the range of this study, no marked loss in the shielding performance was observed for heavy-weight concrete.
Most underground retaining walls are constructed from massive concrete, which causes thermal cracks to appear in wall due to heat generation. Crack control joints are generally used as countermeasures to prevent cracking, but they necessitate section loss rates of approximately 20% -30% of a wall’s diameter. The authors developed a new crack-control joint, installed only in the surface region where tensile stress is caused by the temperature differential between the inner and outer layers of massive concrete. Temperature stress analysis confirmed that tensile stress was concentrated in the experimental crack-control joint. In field application to walls at a construction site, cracking was not observed anywhere other than the installation location of the experimental crack-control joint.
Welded beam-to-column connections have been widely used in Japan, however, one of the disadvantage compared to bolted connections is the difficulty and low production speed. Bolted connection may be an alternative way to higher production speed, however, very few quantitative and actual data have been reported. This paper reports the fabrication time for web-clamp type connections as one of the bolted connections. From the work record for an actual steel building construction using the Web-clamped type connections, the work time of each production step was aggregated and compared to that of conventional welded connections. As a result, it was shown that the fabrication time for Web-clamped connections is 30 % less than the estimated fabrication time for conventional welded connection, thanks to the smaller number of parts and the less quantity of welding.
A wind resistant performance test method for mechanically-attached waterproofing systems has been developed using three pressure loading actuators (PLAs). The chamber to which specimen is attached is divided into three rooms. The PLAs generates fluctuating wind pressures in the rooms separately using the time history of wind pressures measured at different points on the building model in a wind tunnel. The test results are consistent with those of full-scale measurements performed on a test building. Furthermore, the dynamic response of the roofing system is simulated by a finite element method. The result of the analysis is consistent with the experimental results.
In recent years, there are environmental changes such as an increase in high-strength concrete and progress of curing materials in cold weather concreting. Therefore, a questionnaire survey was conducted to elucidate the actual condition of cold weather concreting for ready mixed concrete suppliers and constructors. Based on 458 responses, this paper showed the implementation situation by region on cold weather concreting, and subjects of this.
This paper deals with investigation in the actual state on social insurance situations and qualification allowance for rebar technician in Kanto area. Therefore, we investigated certified rebar worker and register rebar sent worker. Moreover, we conducted a questionnaire survey about social insurance situations and qualification allowance of rebar technician in Kanto area. As a result, Construction companies request deploying qualified person into construction sites, but in most cases Construction companies don’t pay rebar technician qualification allowance.
Quantitative nondestructive evaluation technique of anchorage zone of post-installed anchors by using electromagnetic pulse method is presented. For quantitative evaluation, several indexes are introduced, which are derived from received signals and their frequency spectra. The effectiveness of the technique is demonstrated by experiments using anchors installed in concrete test blocks and also those installed in an existing building.
The purpose of this study was to develop tactile walking surface indicators for floors with fewer barriers for visually and non-visually impaired people. First, an elasticity test was conducted with 16 different materials. Second, three products with different thicknesses were produced, and interview surveys were conducted with blind and sighted people using four test products: the three that were produced and one ready-made product. The results confirmed that the products having thicknesses of 1 mm, 4 mm, and 7 mm were evaluated as having “easy walkability” and “easy recognition of end point” when compared to the ready-made product.
The purpose of this study is to evaluate the human impact of falling debris of tempered glass for school. In this study, influence of glass debris on human was confirmed by experiment using pig skin. Glass debris of 3.35 to 8.0 mm in size were more than two-thirds of the total. As a result of dropping 100 cases on the pig’s skin, 20 cases were found the scratches on the skin. The larger the weight and speed of the glass debris, the more the scratch tended to increase.
The introduction of photovoltaic systems is progressing rapidly with the expansion of demand for renewable energy. However, in recent years, accidents are seen in some systems due to natural disasters caused by strong winds and large typhoons. On the other hand, wind resistance tests have not been established to evaluate the strength of the support structures for PV system. In this paper, we develop the world’s largest test apparatus designed to examine the wind pressure resistance of the ground installed PV system. By using the apparatus, the testing method is reported to evaluate the strength of the support structures for PV system.
It is aimed at finding the application limit with respect to the simple evaluation method of a stud type vibration control structure with the nonlinear viscoelastic damper. We examined the application limit by using the input level of the earthquake motion as parameters. It was confirmed that the accuracy of this evaluation method is lowered in the boundary between the damper installation story and the non-installation story. This tendency becomes prominent as the input level of the earthquake motion increases and the ductility factor increases. This method can be evaluated very accurately as long as plasticization does not occur.
Seismically isolated buildings have low redundancy against extreme ground motions. The safety margin of seismic isolated buildings is evaluated in this report and, their design is based on the general design criteria for extremely rare ground motions using the incremental time history response analysis. The superstructure is analyzed with a moment frame model and is compared with a shear wall frame model aiming to improve the redundancy and the safety margin. In addition, time history response analyses are performed for long-period ground motions to compare the seismic performance of both models.
A large amount of the ground supporting building 70 had been lost by erosion and scour in the past severe typhoon. The big score hole was recently backfilled by air mortar for stabilizing building 70. The change in dynamic characteristics of building 70 was tracked with the increase of backfill material every two hours by the vibration sensor network in Gunkanjima. It is reported that dynamic characteristics of the superstructure varies globally and locally with the progress of backfilling.
Static friction coefficient is increased depends on the waiting time. We confirmed this by horizontal loading experiment of building using elastic sliding bearings. In order to confirm the influence on the earthquake response, we developed a program with a friction model considering the static friction coefficient, and we conducted the seismic response analysis of the target building. As a result, at level 1, the maximum layer shear force response increased and the maximum displacement response sometimes increased. At level 2, the maximum layer shear force response was sometimes the same or increased, but the maximum displacement response sometimes increased.
Technical standard of Cross Laminated Timber (CLT) was announced officially in 2016. Because the earthquake occurs frequently in Japan, cautious understanding on the ultimate state of CLT is necessary. Especially the shear strength of the CLT panel as a wall and its joints are important for structural design. In this paper, a double shear testing on the shear strength of CLT panel is reported. The specimens of the CLT panel were jointed using drift-pin with inserted steel plate. The results of the testing one specimen (3layer 3ply) shows the shear strength was decreased rapidly after peak load recorded.
Timber joints composed with bolts or drift pins and steel inserted plate were studied. But experiments and numerical analysis considering gaps are recommended. In addition, experiments for whole parts, especially horizontal braces, have scarcely been reported. Therefore, authors conducted tensile and cyclic load tests of horizontal brace using glued laminated timber with the steel inserted plate.
We ascertained the strength properties of a commercial dovetailjoint. Shearing tests were performed for four section sizes of a commercially available dovetailjoint to ascertain its strength properties. To additionally establish the effect of differences in tree species, the tests were conducted for three species.The optimum dimension of the shape that needs improvement was calculated by the shear yield strength estimation formula. As a result, shear yield strength is improved when koshisei of commercial dovetailjoint with cross section size 105 mm×180mm is increased by 15mm.
In this study, we developed a bearing wall with higher strength using CLT for seismic reinforcement of the first floor part of wood frame-based building method housing, and experimentally confirmed the in-plane shear performance of the load bearing wall. We also attempted numerical analysis of the shear performance of the high-strength shear wall based on the performance of each element used in its construction. The results showed that our high-strength shear wall attained its target value, and applied numerical analysis was effective for evaluating its safety.
The authors conducted horizontal loading tests on timber assembly continuous columns as part of the development of timber skeleton structures with the objective of long-term maintenance of small buildings. Through horizontal loading tests of the continuous columns, the authors shed light on the basic structural performance of this construction method. Additionally, experimental values were recreated through incremental analysis on the basis of a deformation modal theory constructed by shearing, bending, rotating, and swaying the continuous columns. Further, the applicability of the theory was confirmed through a comparative evaluation of experimental and theoretical values for the distribution of distortion.
In order to investigate the seismic performance of the existing RC buildings more accurately, it is necessary to clarify the mechanical properties of concrete. In this paper, the mechanical properties of concrete from six existing buildings constructed in 1953-1974 before the execution of demolition are discussed. The compressive tests and the splitting tensile tests were performed with the obtained concrete cylinders. Modulus of elasticity, strain at the maximum strength, stress-strain curves and tensile strength are discussed in comparison with the estimated values.
A preservation of a property of the building structure is important as with its safety. Based on this perspective, the studies on performance-based design incorporating economic indexes have been carried out both in the US and Japan, but the evidences of the repair costs are rarely opened. The authors carried out both integrated estimates and hearing survey of repair costs of a damaged earthquake resistant concrete wall. The estimates of the repair costs are compared with those of the data base opened in US. Finally, the repair costs corresponding to damage levels used in Japanese standards are presented.
Corrugated fold roof deck plates are widely used for roofs in steel building structures, typically connected with puddle welding. These plates are designed to have sufficient strength and stiffness against loads in out-of-plane directions such as wind and snow. Moreover, they have certain capability to resist loads in in-plane direction. In this research, in-plane shear performance of the roof deck plates is evaluated both experimentally and analytically. Detailed FEM models are created for the puddle welding connections. Inelastic behavior including local buckling and rapture of the connections and deck plates are well simulated.
Structures of temporary seating using scaffoldings have some connections which enable to easily assemble, disassemble and reuse members. The connections have non-linear stiffness through slipping and loosening in exchange for the high workability. The nonlinearity makes seismic responses of the structures complex. The structures are generally designed assuming that they are braced frames without considering the nonlinearity. A seismic response analytical model for the structures is suggested by static loading tests and shaking table tests using unit basic structures. It is verified that the model simulates response results of shaking table tests of large-scaled structures.
In recent years, the application of repair and reinforcement method of existing structure is advanced with CFRP. In this method, on-site hand lay-up molding/bonding or CFRP plate bonding is often used. However, in the case of hand lay-up method, the construction time is increased with the number of layers. Also, the case of CFRP plates, it is difficult to apply without planar surface. Then, a method with more workability and high reinforcement effect should be developed to increase the structural performance. In this study, we propose a technique that can increase stiffness rapidly and efficiently by using pre-formable carbon fiber sheets that can solve these problems by vacuum assisted resin transfer molding and bonding method on the surface of existing structure and we demonstrate its bending strength by experiment.
In this study, it was aimed to discuss a method to evaluate the reaction-to-fire performance of fire-retardant-treated wood which was used as building facades taking an aging deterioration into consideration. Accelerated weathering test method and the reaction-to-fire performance of fire-retardant treated wood were examined. As a result of the accelerated weathering test, it was confirmed that the initial performance was deteriorated in the Reaction-to-fire test. In the contrary, regarding the façade tests, specimens evaluated by accelerated weathering test showed a little effect.
Regarding scattering coefficient that represents acoustic scattering capability of architectural surfaces, a reverberation room method for measuring random-incidence values has been standardized in ISO 17497-1. Besides, an alternative method for measuring normal-incidence values between parallel walls was recently proposed. In this paper, a 1/4-scale-model measurement system integrated for the two measurements is newly developed, where converting the former system into the latter system in a rectangular room with a circular test sample. In order to validate the converted system for normal-incidence scattering coefficient, the test arrangements are examined in experiments, and the measured results are compared with numerical results.
To investigate the sound absorption property necessary to support activities in a nursery classroom, we conducted experiments by installing sound-absorbing materials in the kindergarten classroom. We changed the sound absorption property of classroom in steps, analyzed the change in the sound environment and its influence on activities. As a result, it is suggested that conserving a sound environment supports multifaceted activities in the nursery classroom, and an average sound absorption coefficient of 0.25 or more is necessary to achieve this.
A temporary sensor network using 6 portable microtremor sensors is formed to estimate modal properties of a reinforced concrete office building under ambient vibrations. The building is almost always exposed to traffic vibrations due to railway trains and road vehicles. Therefore, ambient vibrations are composed of wide varieties of successive traffic vibrations. Based on the measurement results, it is shown that modal properties in translational and torsional vibrations of the building can be accurately estimated by an appropriate data acquisition and processing method even in noisy environments.
A temporary sensor network using 6 MEMS acceleration sensors is used to evaluate the vibrational characteristics of SRC office building globally and locally under environmental vibrations. Ambient vibrations inside and outside the building are measured after setting up the appropriate sensor network. The distance attenuation in soil, the input loss effect of foundation, and the amplification in a building skeleton and in individual members can be estimated at once by applying the proposed method.
This paper aims to propose calculation methods for Phase Change Material (PCM) considering its installation status as construction materials. We conducted experimental measurement of PCM in a heat insulation box. By trying to replicate the measurement by calculation, we found several points to care when calculating PCM.
The authors planned and surveyed a passive design house installing an air conditioner under the floor. From the results of the measurement, thermal environment in winter was good, but in the case of floor cooling in the first summer, vertical temperature distribution was large. In the second summer, wall mounted air conditioners for cooling were added and the indoor thermal environment was improved. Measured total energy consumption of the house was about half amount of the value estimated by Japanese energy standard.
This paper studies on the applicability of an alternative wastewater management by installing constructed wetland with vegetation and ecological lifestyle to reduce pollution of domestic effluent, in a remote island, Ogi Island in Setouchi, Japan, where the population is declining and the infrastructure has been old and difficult to maintain. By reviewing literature and clarifying the features, it is found that the alternative wastewater management can be applied to Ogi Island, since there is enough space for it, and it is more economical, and possible to be maintained by community members, comparing with installing septic tanks.
KINDAI University and various enterprises proposed a Zero-Energy-House(ZEH) called “ENEMANE R HOUSE” in ENEMANE HOUSE 2017. A real size house was built in Osaka and its environmental performance was measured in November 2017. This report presents the energy-saving and environmental technology adopted in this house and its effects. The findings show that this house achieved a ZEH status sufficiently and has excellent environmental performance.
In this paper, with a purpose to clarify the viewpoints and effective measures in reducing energy consumption at experimental research facilities in campus, we conducted a detailed energy-consumption examination on physics and agricultural research buildings, and as a measure to save energy without hindering the experiment ongoing in the facilities, mapped out “renovation of experimental air supply and exhaust system”. As a result, it has been clarified that it is possible to reduce power consumption by 23% without hindering the experiments and indoor comfort.
Ogi-island is characterized by its stone retaining walls and alleys, resulting in a comfortable calm-wind environment. The demolition of vacant houses along the island has increased directly affecting the village’s wind environment. This study investigates the within Ogi-island village pedestrian wind environment with smartphone anemometers. We obtained following results: 1) Wind speed within the alleys parallel to contour line was small. 2) Wind speed within alleys perpendicular to contour line was also small. 3) Wind speed at several points on the alleys opened to the sea was larger. 4) Wind speed at high altitude areas was similar to that at coastal areas.
This report is on the double-skin facade system of NCR building, which was the first to be installed in Japan in 1962. This report also includes the result of the environmental measurements of it in 2015, following over 50 years after initial construction. The original drawings showed that the facade system was exquisitely designed to integrate the performance of thermal control, fire prevention, rainwater drainage system and its maintenance. The result of the measurement showed that the thermal performance was high as at that time and the performance at the time of its original completion had been maintained even now.
This study explored the changes of space radiation dose rate both indoor and outdoor associated with a decontamination operation for a wooden house in a low dose area. As a result, the maximum space radiation dose rate measured at 1 m height from the floor inside the house before the decontamination operation was 0.19 µSv/h. The maximum space radiation dose rate after the decontamination operation was 0.12µSv/h. Furthermore, the results of a comparison of the space radiation dose rate between pre- and post-decontamination operation indicate a decrease in the rate at most measurement points, and the average reduction rate of the space radiation dose rate in the post-decontamination operation condition was around 20%.
Air temperatures in agriculture greenhouses may become too high in summer season for cultivating some plants. So we investigated the effects of a groundwater cooling system for the inhibition of temperature rise under high temperature conditions in a tomato cultivation plastic house. The tests were carried out from June to August 2018, in the site of Ishikawa Prefectural Agricultural Experiment Station. The main features of this research are as follows: (1) air temperatures in night-time were reduced by the interior air circulation and (2) relative humidity in day-time were increased by the mist spraying in the house.
This study explored changes in spatial radiation dose rate both indoor and outdoor associated with a decontamination operation for a wooden house in a high dose rate region in Fukushima. As a result, the averaged spatial dose rate at 1m height from the floor before the decontamination was 1.73μSv/h and the dose rate after the decontamination was 0.86μSv/h. Furthermore, the results of a comparison of the dose rate between pre- and post-decontamination indicates a decrease in the dose rate at almost all points. The reduction rate of spatial dose-rate was 40 to 50% at the center of the house.
After summarizing the changing process of temporary housing, we consider the influence of the type of moving in, layout plan, and location on the community. As a result, it is required to improve housing quality and workability. Also in the cases that a method of moving in is lottery, about 20% of inhabitants have no interaction, and formed small communities. So it’s better for the previous community to be maintained. The plan of meeting places is rated high as an interchange place. We could not find the relationship between the scale of the sites and the community, the location and the community.
The purposes of this study are clarifying the meaning of the open and utilization and the possibility for maintenance of the privately-owned houses as tangible cultural property. The actual situations of the maintenance and the open and utilization of the houses were grasped by the questionnaire to all privately owners. By the result of analysis, it was cleared as follows. 1)The open and utilization stimulate repairs of houses at the non-living cases. 2)The open and utilization cause owners’ will to maintain at the living cases. 3)The information sharing for operation brings the possibility for dispersion of the owners’ burdens.
This paper identifies residential preference of child-rearing households based on questionnaire and interview survey. The results of this paper are as follows : 1) Child-rearing households tend to move in the same area, and in area well-known; 2) Single parent households tend to value the education environment and local community; 3) Working single parent households tend to value the proximity of housing, a school and a workplace to improve efficiency of commuting and taking their children to school; 4) Child-rearing households with children aged 0to2, 3to5, and schoolchildren tend to value housing performance, educational environment, and children’s school and friendship, respect.
This study develops a location optimization planning framework for elder care facilities in a local city. Using a target ratio of facility supply, it is relatively easy to estimate the number of target facilities during maximum demand. A spatial perspective is added for locating new facilities and allocation of the care requiring seniors into facilities that incorporate GIS-based concentration of urban functions and daily life orientation of the elderly. This suggests that it should be possible to construct an efficient nearly optimal service supply system by locating and allocating facilities that accurately reflect spheres of daily life of the elderly. By performing similar estimates in 2040 when the elderly population is smaller, we are able to estimate facilities that can be decommissioned and/or torn down. Shortcomings attributed to estimation errors, limited assumption conditions, prioritization in locating new care facilities, and other biases in locating of current facilities are also pointed out.
The aging issue in China is particularly severe in the rural areas. This study investigates the subjective needs towards supportive services by the elderly in two typical villages in northern Zhejiang by questionnaire and interview. The result depicts the need in daily-care, health, education, recreation and self-fulfillment by the rural elderly, showing their strong need of economic insurance and chronic diseases care. Moreover, the correlation analysis suggests the association between certain personal attributes and the choice of services. The result is expected to serve as a reference for the subdivision of elder users and a pertinent provision of corresponding services.
In this study, bottlenose dolphins existing breeding facilities are researched for improvement method in Japan. First, we investigated standards for dolphin breeding environments in the United States, Animal Welfare Regulations which is widely referred. Through interview with veterinarians, who are the dolphin breeding specialists, we obtained information about existing and ideal environments for breeding facilities. Based on that, problems of the existing facilities are analyzed, suggestions for improvement and improving method are described.
This study aimed to analyze the exhibition structures and the facility planning in museums and memorials which commemorate catastrophes, with the site of remembrance, configuration of the exhibition rooms, and the character of the facility, based on the knowledge of the historical science. The patterns of the room configurations are classified into some groups with the number of rooms for historical exhibition and the relationship with the specificity of the site. In the latter, the configuration would contribute to create collective memories with visitors’ notation.
The purpose of this experimental study is to clarify dimensions of toilets in a private room in facilities for the elderly. The method is the motion analysis, and the number of participants was ten people. ①When dimensions of toilets were less than 900mm in depth and 1500mm in frontage, it is impossible to do excretion assistance. ②When a wheelchair was placed perpendicular to a toilet, the dimensions that can be assisted without burden was 1300mm in depth and 1800mm in frontage. And when a wheelchair was placed parallel, it was 1400mm in depth and 2000mm in frontage.
This study focuses on the difference of going-out activities and social interaction between the residents of an inner-city temporary housing and those of suburban one in City I in Fukushima Prefecture. As results of the structural interviews to 48 residents, it was found that residents of the inner-city temporary housing went out as often as suburban ones, and both had similar level of communication with localities. In inner-city temporary housing, residents were able to determine individually ways to go and communicate, while some unsociable ones tended to be left isolated. In suburb, temporary housing residents had limited opportunity to go out because of traffic restrictions, thus they tended to communicate mainly with each other. Many of them did not want local acquaintances.