Seven brands of air-entraining and high-range water-reducing admixture containing viscosity modifying agent (VSP) were compared by mortar test. As a result, it was shown that several VSP required the surplus dosage. And the surplus dosage brought increase of the high viscosity of mortar. In the case of surplus dosage, the difference in flow time of funnel test of fresh mortar between VSP and air-entraining and high-range water-reducing admixture (SP) was over 10 seconds. Therefore, when using VSP, it’s important to decide dosage at the range of standard dosage of each manufacturer.
In this research, the relationship between rusting and non-rusting of lath was evaluated through 30 years of outside exposure in YOKOHAMA using light mortar and general mortar developed and sold in 1986. The results confirm that there are many cases of full-cross-section neutralization in the exposed test bodies after 20 or 30 years. However, as for rust in the lath, rust is barely visible near the center of the section, even where neutralization is taking place.
The purpose of this study is to increase the safe use of recycled aggregate concrete-Class M mixing with recycled aggregate class L and regular aggregate. The evaluation results of recycled aggregate class L may differ depending on the sample pre-treatment method and testing method. Thus, it is necessary to perform quality control in combination with other tests. As suppression methods, the specified value of total alkali amount can be satisfied by appropriate use of cement and admixture. In addition, the effect of alkali-silica reaction suppression by using a certain amount of fly ash type II was clearly recognized.
In order to clarify the actual state of the inspection method of the transport pipes attached to the concrete pump with a boom, this study carried out a questionnaire survey for Japan concrete pumping association. The main points of the results are as follows. The inspection method differs depending on the type of steel pipe, and hoses are visually inspected. The inspection frequency is once a month for steel pipes and docking hoses, and every time before work for tip hoses. The records of inspection results and reports to general contractors are more for steel pipes than for hoses.
In reinforcement construction, making a shop drawing and inspection of bar placement are matter of cardinal importance. However, there are no reports investigating these actual states and problems. Therefore, the purpose of this study is to investigate problems and actual state of shop drawing and fabrication book, and construction control and inspection of bar placement. As a result, this paper showed the actual state of reinforcement have worked for under the leadership of the reinforcement contractors. And, there has been a difference of instruction contents for each position who carry out inspection of bar placement.
The entrance tollgate of expressway is in severe vibration environment caused by the traffic. In order to detect the deterioration of the roof slab of reinforced concrete tollgate supported by a single row of columns, traffic-induced vibration of the roof slab was measured for about two years. The results obtained from the long-term monitoring show that the Lissajous figure of displacement, angle of the slab, the first natural frequency and stiffness in the vertical direction are important and valid for detecting the deterioration of the roof slab as monitoring methods.
In Japan today, pets such as dogs and cats are kept indoors. Countermeasures against indoor pollution and maintenance of sanitation environment are important in response to rising awareness of living environment with pets. We focused on the problem that interior wall materials are damaged by pet scratching. The purpose of this study is to examine the relationship between the physical properties and visual qualities of plaster-patterned (Hikizuri) wall material and scratches. The influence of factors such as the scratch direction of the wall on impression reduction is clarified by sensory evaluation, and used as basic data for building material development with the less repairing.
We have proposed to install photovoltaic (PV) panels parallel to the flat roof of a building with small gap between them. The gap may cause a pressure equalization effect on the PV panels, resulting in a reduction of the wind forces. In addition, the wind pressures acting on the waterproofing system will decrease too. In the present paper the wind pressures underneath the PV panels are evaluated by a numerical simulation using the unsteady Bernoulli equation together with the time history of external pressure coefficients on the roof of a building model obtained in a wind tunnel.
Building 31 was constructed as one of the wave-protective buildings in Gunkanjima. High waves and strong winds have been often acting on the building during typhoons. High waves induce direct wave pressures and indirect ground vibrations propagating from adjacent seawalls. Strong winds generate positive and negative wind pressures. Dynamic behaviors of building 31 during two typhoons in 2018 were recorded by vibration sensor network. The dynamic behaviors during typhoons are investigated through long-time rms responses and short-time impulsive actions.
Building 65 is the largest structure that lies between rock mountain and reclaimed land in Gunkanjima. It consists of three buildings built at different ages. Rough seas surrounding the island are sometimes caused by seasonal winds from north in winter and typhoons from south in summer. The dynamic characteristics of building 65 under rough seas in winter and summer are investigated, taking into consideration structural configuration, damage state, topographic and soil conditions.
This report describes variation of long-term dynamic characteristics of a super-high-rise RC building constructed in Osaka plain. This building is equipped with the simultaneous earthquake observation system at pile tip, ground surface along with upper building. Seismic records have been obtained for more than 30 years including the 1995 Kobe earthquake. Natural period of the building became longer during the 1995 Kobe earthquake. On the other hand, swaying and rocking ratios to the top displacement estimated from those records are not variated through long-term observation.
Although Horizontal and rotational dynamic characteristics of super high-rise residential buildings has been studied based on recorded motions during the 2011 Tohoku earthquake, vertical dynamic properties were not fully investigated, which must be strongly affected by the dynamic soil-structure interaction. This study investigates vertical responses of the nine super high-rise residential buildings located in Kanto area using recorded motions including the 2011 Tohoku earthquake. Transfer functions of top responses to ground surface are varied due to vertical soil-structure-interaction with strong dependency of dynamic impedance function.
In this paper, cyclic shear-bending analysis of concrete-filled-tube (CFT) column using E-Simulator, which is a large-scale detailed finite element analysis system developed by NIED, is verified and validated. The solid element mesh is verified by varying types and sizes of solid elements. The effects of element types and sizes on analytical results are discussed. Two cases of experiment under variable axial load are simulated for validation. By comparing analytical and experimental results, it is shown that, the cyclic shear-bending behaviors are reproduced by E-Simulator. The computed internal damage of filled concrete is visualized and discussed.
It is known that the high damping rubber used for building damping material may show a hardening phenomenon when the shear strain attains beyond 2. For reliable simulations considering this hardening effect, an additional hysteretic rule of high-damping rubber is proposed based on the result of cyclic loading tests. The hardening effect in the hysteretic rule is derived by adding a new element considering the difference of stress in the large strain range between the existing hysteretic rule of high damping rubber and the cyclic loading test results.
The purpose of this study is to investigate the tensile strength degradation of PVC coated polyester fabric membrane material for movable temporary building, adopting an air-supported structure. The influence of the inflation-deflation and the folding membrane process on the tensile strength degradation has been observed by comparing the result of the test after the 4th usage and the result of unused material. The subject building has been used 4 times for 5 years, and according to the result, the tensile strength is being kept as it was unused. However continuous data accumulation is needed after further usage of this material.
In this paper, I present the experimental results of traditional mud walls subjected to constant amplitude multi-cycle loading. The number of the loading times were considered the earthquake response analysis results of the models. From the experimental results, I examined the strength deterioration and the change of the hysteresis loop. I discussed the strength deterioration factor, which is considered the multi-cycle loading or earthquake motions.
In the previous paper, we presented a mechanism to improve the seismic performance of external thermal insulation wall with cellular plastic foam for wooden houses. In this paper, we present the test results to clarify that the influence of cellular plastic foam compression characteristics in the wall, the effect of furring strips installed at the horizontal edge of the structural board and the influence of nearness between the fasteners to fix the external thermal insulation system and the nails to fix the structural board. Finally, we propose the structural values for seismic retrofit to wooden frame houses.
In the previous paper, we presented a mechanism to improve the seismic performance of external thermal insulation wall with cellular plastic foam for wooden houses. In this paper, we present the test results of the wall with fiber insulation instead of the cellular plastic foam. The external thermal insulation wall with fiber insulation usually have furring strips for the exterior, because fiber material does not have compressive strength to keep the exterior on it. We propose some installation patterns of furring strips, and the test results describe the vertical strips bring more toughness for the wall than the horizontal strips.
Wood bracing shear walls are usually installed in not only residential houses but also medium or large-scale wooden buildings. It is no problem to provide bracings in residentials. But, in case of providing bracings in medium or large-scale wooden buildings, it will be difficult that the bracings exert its strength of shear walls which is prescribed in Japanese Building Code. The purpose of this study is to clarify the specification for exerting its strength in medium or large-scale wooden buildings throughout the racking test of full-size shear wall. And the purpose was achieved by this experiment.
In this report, we confirmed the dynamic behavior of the timber frame structures with visco-elastic damper and elasto-plastic member and constructed a shear spring model. First, dynamic and static loading tests of passively controlled timber frame were conducted in order to examine properties. Also, the characteristic value of damper was calculated. Second, static loading tests were carried out against the frame in two states ; without damper and rigid damper. The behavior of timber damping frames can be reproduced roughly by using a nonlinear spring in a shear spring model.
Wood grid walls are widely used as a seismic-load resisting element for upgrading traditional Japanese wood structures. However, because the elements are expected to be joined loosely due to unavoidable drying shrinkage, the current design provisions attribute small initial stiffness to grid walls. Consequently, an experimental study was conducted to examine how the seismic performance of grid walls may be improved by the use of compressed wood. Compressed wood has shape recovery behavior by compression under low temperature. These elements can be used to overcome the stiffness reduction of wooden interlocked joints caused by drying shrinkage.
A new implementation technique of Rayleigh Optical Frequency Domain Reflectometry and its measurement accuracy are discussed. A reinforcing bar and reinforced concrete specimen were instrumented with distributed fiber-optic sensor to measure strain profiles distributed along the specimens. The reinforcing bar and reinforced concrete specimens were tested in uniaxial tension. The measured strain profiles were compared to traditional electrical resistance strain gauges (RSG) to verify the reliability. Compared with the results coming from RSG, it was observed the fiber-optic sensor provided reliable measurements. The distributed fiber-optic sensor was able to detect the formation of cracking and pinpoint the bond deterioration zone.
When steel fibers is added into concrete mix, the tension stiffening effect of the resulting concrete is thought to be different from normal concrete. At first, pull-out tests of reinforcing bars from steel fiber reinforced and normal concretes were carried out. Subsequently, a 3D finite element analysis was conducted to verify softening characteristics of the steel fiber reinforced concretes. And then, a 3D finite element analysis of beam-column joints made of steel fiber reinforced and normal ultra-high strength concretes was conducted using a material model deduced from the pull-out tests. The analytical results generally agreed well with the experimental data.
A questionnaire survey was carried out for a SRC apartment building damaged in Kumamoto earthquake (2016) in order to develop a seismic design method considering inhabitant’s mental stress. The design framework, calculation method of damage limit and damage allowable time which depends on the stress of inhabitants were discussed. Moreover, some components in the residential building which damage should be prevented were examined. Based on the results, the validity of the seismic classification method from the viewpoint of functional resilience, proposed by Building Research Institute, was discussed.
The present paper discusses the wind pressure coefficients for the main wind force resisting systems of low-rise gable-roofed steel buildings, based on a wind tunnel experiment and a two-dimensional frame analysis. Focus is on the bending moments involved in the members as the load effect. The most critical condition occurs on the windward frame in a diagonal wind. The largest bending moment was compared with that predicted from the wind pressure coefficients specified in the Japanese building standards. Finally, more reasonable wind pressure coefficients for designing these structures are proposed based on the LRC method.
In recent years, the use of FRP structural members has been promoted. Usually, metallic rivets and bolts are used for the connection of FRP structures. On the other hand, fiber reinforced thermoplastics (FRTPs) are developed in composite material fields because it can be remolded easily by heating, and has good economic performance. In this study, we propose the connection method using FRTP rivets for FRP materials to ease the construction procedure and provide stable connection strength. Then, it is confirmed that the connection using FRTP rivets can provide quite stable strength and smooth stress transferring.
Three R/C column specimens with CLT wing walls were constructed in 2/3-scale and tested under cyclic loading simulating earthquake motions. CLT wing walls were fixed to R/C column with joint metals and epoxy resin. Test specimens showed higher lateral load carrying capacity and ductility despite failure modes of CLT wing walls. Joint metals and loading method had influence on axial strain distribution of CLT wing wall. For the test specimens with joint metals, estimated shear force on the vertical joint surface exceeded shear standard strength of CLT.
We have devised a suspended ceiling with an oblique member, which is a C-section steel changed to a square steel pipe, for the ceiling foundation. In order to confirm the earthquake resistance of the devised ceiling foundation, a ceiling unit test was conducted. As a result, the following was found. For specimens with suspension lengths of 0.5m, 1.0m, and 1.5m, the earthquake resistance decreases as the suspension length increases.
According to the revision of the Building Standard Law in Japan in 2018, a new 10 minutes fire rated door was stipulated. Therefore, in order to grasp the flame interruption performance of the existing light steel door and to develop the specification of the 10 minutes fire rated door, flame interruption performance tests were conducted. As a result, it became clear that the followings are important as a specification required for the 10 minutes fire rated door. 1. The steel plate (0.5 mm or more) should not fall off by heating 2. Use tempered glass with fire protection performance of 5 mm or more in thickness etc.
Case study on an office building is conducted using a novel performance-based method for verifying compatibility of fire spread prevention performance of a building with that required by the building standard law. In order to relax the restriction on the fire-resistive performance of the inner wall and floor to be equivalent to the quasi-fire-resistive construction of 45 minutes, it is necessary not only to improve the fire-resistive performance of the external wall and window, but also to subdivide the inner space into several fire compartments.
The thermally renovation method for built houses is expected to contribute to the global warming prevention. In this paper the analyzed results of the indoor thermal environments during heating season and annual energy consumption in four detached houses before and after the retrofit were presented. In particular, non energy benefit (NEB) could be useful for the evaluation of cost benefit after renovation. It is said that there are three kinds of renovated methods for improvement of thermal performance on the envelopes in according with the width of insulated area. This paper focuses on the environmental improvement of houses through the whole and partial renovation method.
This research aims to propose an evaluation method for the environmental performance of a passive house. Using the method, average room temperature and fluctuation of room temperature in a day are predicted from outside air temperature and solar radiation data. Furthermore, the heating load is predicted easily.
As a method of suppressing cold drafts from a staircase leading to an open ceiling space, without reducing the openness of the space, we proposed stair surface heating that warms the surface of the stairs. We confirmed the effect with an experiment conducted in an actual house. As a result of the experiment, it was shown to be possible to suppress cold drafts by heating the surface of the stairs. The degree of suppression was influenced by the rotation of a ceiling fan.
This study is on the effect of pre-cooled outdoor air cooling and water sprayed cooling on a movable temporary building, adopting an air-supported structure at room temperature. By experimenting the suitable air conditioning methods for a movable temporary building and an air-supported structure, the room temperature changes have been observed. The pre-cooled outdoor air cooling prevented the room temperature from rising, and the water sprayed cooling decreased the room temperature effectively. However, there is still room for improvement on these methods such as the duration of the cooling and combination with other methods, the further studies are needed to improve.
Since the 2020 Tokyo Olympic and Paralympic Games will be held during the hot summer, promotion of outdoor heat is an urgent issue as one of environmental measures. “Cool Tree” as a cool spot to create a beautiful shade of lumber with laminated wood, operating with zero energy using only solar energy, with the concept of “design like Japan”, “complete off-grid system” and “ultimate recycling ecology” was developed, and field measurements were carried out.
Currently, when investors are considering investing in companies, they are considering ESG (E: Environment, S: Society, G: Corporate Governance) of companies as criteria. In response to this trend, the Ministry of Land, Infrastructure, Transport and Tourism announced a new certification scheme aimed at promoting the spread of real estate beyond ESG in order to promote global investment acquisition by Japanese real estate companies. For this reason, there is an increasing demand for a system for evaluating real estate excellent in worker health and comfort from the viewpoint of improving intellectual productivity.
This study aims to clarify living conditions at the shelter and temporary housing in Kashima where 11 temporary housing complexes were built in each settlement. As a result of the interviews with government workers and leaders of inhabitants, it became clear that the disaster victims could continue to live autonomously in neighboring community centers, which were used as a shelter, and they could move into the temporary housing located within 750 meters of their own home. It’s because they had the social resources such as residents’ association, and the spatial resources such as local parks where government build temporary housing.
The purpose of this study was to obtain the tasks and guidelines for the appreciation support with the digitized collections and the library rooms Museums of in Tokai area. The appreciation support tool in target museums is in the middle of preparation and a stage for visitors. Digitized data is easy to utilize when having purpose such as explanation, it turned out that it leads to educational activity. It was found that flexible use of the library rooms enhances the synergistic / complementary action with utilization of digitized data and partnership activities, leading to clearer characteristics of the museums.
This study aimed to report on the result of the field research on care space of Day-Service Center for children with severe motor and intellectual disabilities. We recorded the attributes of users, usage of the interior facilities and the behavior users. The result of the study are as follows. 1. Users spend most of time on the mat or bed in a day. 2. Staffs took care of user on the mat 1287 minutes in a day. 3. Staffs transferred the user between the mat and buggy, cushioned chair 309 minutes in a day, etc.
We drew types and grasped the situation of each type at medical type facilities for children with disabilities in Japan. The purpose of this study is to extract typical facilities from the derived types, and to clarify the characteristics of the types with the attributes that the degree of disability of children is severe. We investigated four aspects: (1) Capacity of facilities, the number of children and adults, and major disabilities and severity of disabilities for children. (2) Clarify the characteristics of each type. (3) Characteristics of typical facilities for each extracted type.
The widespread use of mobile devices like smartphones recently has lead many to use them while sitting for long periods, and the strain of this on our bodies are well documented. The authors developed an experimental chair that can be adjusted for dimension and angle. In this research, setting the chair at every seating styles from the Kohara and Terakado prototype chair, as well as a backless stool, we observed the test subjects both inputting into and reading their device, doing so in different sitting positions, and measured the physical load in each position in different seating styles.
This study focuses on the disaster risks and countermeasures at the 12 home stadiums of the Japanese professional baseball. Based on the verification with hazard maps, many stadiums are located on the hazardous area. However, there is a lack of information about it toward visitors around the stadiums. Our questionnaires to the managers of each stadium indicated that their risk perception related to natural disasters are not necessarily consistent with hazard maps, and their intension whether they open stadiums as a shelter in the time of disasters depend on the stadiums. More collaboration will be needed with local governments.
Affected by the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Station Accident, about 16,800 temporary housing was built in Fukushima Prefecture. Among these, 13,408 of built temporary housing, which was built by purchase method of Fukushima Prefecture, was the subject to reuse after their supply period. This research revealed the actual conditions of the temporary housing by the examination and the analysis of framework of reuse system established by Fukushima Prefecture and a case study of relocation and reuse, which were conducted by “transfer”, as a main target.
In a wheelchair user accessible toilet rooms, the height of the toilet seat is one of the important requirements in terms of usability. The purpose of this study is to clarify the appropriate toilet seat height for wheelchair users with different physical conditions. Wheelchair users evaluated the usability of two toilets with different seat heights defined by Japanese industrial standards for sanitary wares. As a result, some wheelchair users were unable to transfer getting back to the wheelchair, depending on the height differences between the wheelchair and the toilet seat. Two toilets different seat heights were confirmed to be necessary.
Recently, a lot of buildings in snow cold districts are adopting as a their own façade. When adopting GCW where an external condition (snow, cold, strong wind) is significant, it is important to reduce heat loss and to get dew condensation prevention performance. This study is performed on desk examination and actual survey inspection first about insulation and dew condensation prevention performance of one building that have adopted the actual GCW in Sapporo city. Finally, we will confirm the possibility of the aim performance afterwards by comparing them.
The purpose of this study is to clarify the actual situation of the use of smoked hidari-sangawara and munaishi in Matsue City and Izumo City in eastern Shimane Prefecture, where the kawara were produced. For that purpose, report survey, interview survey, and field survey were conducted. In both cities, it is difficult to obtain smoked kawara, and demand for munaishi is low. When replacing the roof with glaze black of migi-sangawara, it is necessary to consider whether to maintain the use of munaishi, which is still in production.
In town development aiming at smart community, the town’s goals are various, so the viewpoint of what value can be obtained for the town users by the utilization of new technologies such as ICT is required. Also, in the process of town development, it is important to share purposes and to build consensus among stakeholders. Therefore, the author proposes the unique assessment index that categorizes the policies into the values obtained by the town's goals. This assessment index can be used as a communication tool among stakeholders.
Recently the functions of streets as public spaces have been reframed. It is important to understand them not only for traffic-calming purposes but also for creating a “sense of place” in residential streets. The aim of this paper is to investigate an improvement project and the process of “street art paving” in a residential area in Tokamachi City, Niigata. The project’s success factors were due to low traffic street leading to the destination, well-communicated among people involved, judgement by the Public Safety Commission, low cost paving, and the street widening project requested by the residents.
This paper proposes a location evaluation method for computing the value of a location based on landscape-related factors formulated by municipal policy. It also presents the results of using IT terminals to observe the movement of people in the neighborhood of Senso-ji temple, Tokyo and evaluates the effectiveness of the proposed method and its usefulness in local-government planning.
In today’s many-death society, it is likely that many elderly facilities will be required as places to die. However, environment of the end-of-life care at facilities are not yet well established. And there are few consideration of end-of-life care from the viewpoint of the family. This paper reports the results of a survey from the perspective of the family and facilities about the case of end of life in the special nursing home “Shakunagesou”. The bereaved family’s evaluation of “Shakunagesou” was very good. As a reason, basic things such as contact and greetings were also important.