In this report, the opening situation of documents relating to materials and construction for concrete to internet was investigated. In these documents, statutes, standards, relating information and papers which were published by academic organizations are included. At the results of survey, before and after 2000, most organizations opened the documents. JIS can be red and JAS is open only in the latest version. Papers are opened in all organizations, but as for other documents, the term and method for opening on the internet depend on the organization.
Compressive strength and pozzolanic reaction of specimens mixed with fine milled fly ash were examined. Mortar specimens mixed with three types of fine milled fly ash were cured under high-temperature condition in early ages. It was clarified that smaller particle size of the fly ash improved the early strength development of mortar. Moreover, both of finely milling fly ash particle and high-temperature curing in early ages remarkably accelerated the pozzolanic reaction of fly ash. The synergistic effect provided the acceleration of the strength development of mortar.
In CFT construction, unlike the conventional method of RC construction, it is not possible to visually confirm the launch state of concrete after dismantling the formwork. Therefore, in the guideline, quality is ensured by establishing concrete specifications and construction method regulations. Therefore, we considered confirming the filling status of CFT concrete by the long and narrow wetting sensor monitoring system. As a result of the experiment, it was confirmed that the developed long and narrow wetting sensor monitoring system can estimate the filling status of the concrete under the diaphragm of the CFT construction.
This paper reports on the environmental load for CO2 emission reduction of RC buildings and RC members made of blended cement using the physical service life as variables. Case studies and parametric studies of the environmental loads were also conducted using physical service life as variables. As a result, it was shown that the impact on the environmental load differs depending on the cement type, finishing material, and maintenance cycle.
As the life of buildings is required to be extended, we tried to increase the durability of exterior wood by coating it with a paint that is a composite of organic-inorganic materials with excellent weather resistance. An accelerated weathering test comparing the durability of wood coated with various paints and an actual environmental exposure test simulating a wall surface were carried out. As a result, it was confirmed that the developed organic-inorganic composite paint has a durability improving effect on exterior wood as compared with general organic paints.
In this study, loading tests were conducted on RC structural frame with LGS partition wall and steel door as test specimens. In the test, damage observation was conducted to understand damage to LGS wall and steel doors for each story drifts. Among the observed damage was ones thought to be caused by the residual deformation of the seismic wall of RC frame. It was also found that when story drift angle exceeds 1/200, the door required force more than 100N to open and when it exceeds 1/100, the door could not be opened.
On March 11, 2011, an earthquake occurred off the Pacific coast of Tohoku. The tsunami caused by this earthquake resulted in severe and extensive damage to structures in northeastern Japan. Consequently, the establishment of safer design methods has become a matter of social responsibility. In this study, hydraulic tests were conducted using a hydraulics model. Next, a CFD simulation is also carried out, which is validated by a comparison of the results with the experimental ones. Finally, the characteristics of the tsunami forces acting on the isolated and grouped buildings were investigated based on the experimental and analytical results.
In this paper, the damage state classification method based on machine learning is applied to a shaking table test data of a full-scale three-story steel frame. The following results are shown; 1) By machine learning using only the shaking table tests data, it is possible to estimate each damage state classification by linear discriminant analysis. 2) Acceleration data from response analysis as the training data and shaking table test data as the verification data are utilized for machine learning, and damage state classification can be estimated.
Based on the analysis results of the seismic diagnosis design of traditional houses in Kyoto, it has been considered that the surface soil amplification factor indicated in the guidelines may be overestimated. In this paper, we have analyzed the soil model used in the calculation of the amplification factor in the guidelines and that used in the earthquake damage estimation in Kyoto. As a result, the former soil model is not adequate for Kyoto city area. In addition, the lower limit of 1.23 is sufficient for the amplification factor used in the seismic diagnosis of traditional houses.
In this paper, first, an approximation formula for the amplification factor of the surface soil is proposed. However, since most of the traditional houses are located on good soil condition, the lower limit of surface soil amplification factor 1.23 may be acceptable in reality. On the other hand, the large amplification sites are hardly related to the large shaking area during the Hanaore-fault-zone earthquake which is deeply related to the safety of traditional houses in Kyoto. We also pointed out that increase in bearing capacity of houses may increase the deformation response in case of pulse-like ground motion input.
A new fail-safe braking device has been developed to protect seismically-isolated structures against ground motions caused by mega earthquakes. The purpose of the device is avoiding collision between superstructure and retaining wall in base isolation layer, and keeping superstructure within a minimum damage. A full-scale prototype fail-safe braking device was fabricated, and loading tests were carried out. Expected performance was exhibited in the test. Seismic response analysis was also conducted to confirm the effectiveness of the device.
In this paper, we propose a damper with large deformation capacity in two directions using high damping rubber bearings (HDRs) as damping component. Damper unit and horizontal force transmission unit is joined by bearing-type joint, and the vertical force does not act on HDRs. Therefore, HDRs only support the weight of damper unit and deform bi-directional under almost zero compressive stress. We confirmed that the proposed damper act with intended by dynamic loading test using scaled specimen.
This study investigated seismic ground motion intensity to estimate the damage rates of low- and middle-rise RC buildings due to various earthquakes. It calculated the vulnerability functions of analytical models of RC buildings for earthquake motions with different spectral characteristics and evaluated the effects of earthquake motions with different spectral characteristics on vulnerability functions. The results confirmed that the average acceleration response spectrum of the periodic band corresponding to the primary natural period of the building can usually estimate the damage rates of low- and middle-rise RC buildings due to various earthquakes.
Two latticed cylinders of aluminum alloy were 3D-printed and axially compressed to cause elephant-leg buckling. The cylinders were composed of triangular and hexagonal grids. 3D scan was performed to specify the real dimensions of the manufactured cylinders. To perform FE analysis composed of beam-elements, center line-models were extracted from the 3D scanned model using the Rhinoceros+Grasshopper functions. Initial geometric imperfection was specified as well as actual section dimensions. FE analysis and strength evaluation was carried out for comparison and verification on the test results.
Prestressed structure, getting reaction force from additional air-container, is called as Air-prestressed structure in this report. The aim of this report is to investigate fundamental mechanical properties in the axial direction, such as elasticity and loading capacity, through the vertical loading test, of air-prestressed cylindrical structure. Three prototypes, having different size and specifications, are tested and the results are reported. It was found that the top point of some specimens suddenly displaced in the horizontal direction under vertical load. The loading capacity of the prototype is calculated by an analytical solution, and compared to experimental result.
The aim of this study is to establish the design method of a timber semi-rigid frame construction system composed with coupled glulam members jointed by screws with steel side plate and high-tensile bolts. In this paper, firstly we proposed the evaluation method for the out-of-plane bending characteristics of the coupled members with high joint properties on the end. Secondly, we conducted the full-scale out-of-plane bending test for the coupled glulam specimens to grasp the mechanical behaviors. We found that the experimental results showed good agreement with the calculations by the proposed method.
This study aims to develop a knee-brace friction damper for mid-rise timber frame buildings. First, time history seismic response analysis was conducted to investigate the performance of the damper to improve the seismic performance of a four-story timber building. Then, static cyclic loading test on a beam-column joint with/without a prototype friction damper was carried out to verify the effectiveness of the damper. It is found that the damper mitigates slip behavior and increases equivalent viscous damping ratio and equivalent stiffness.
Time history response analyses of horizontal hybrid wooden structures with RC core on one or both sides are conducted considering the elasto-plasticity of the wooden part with Wayne-Stewart model as hysteretic characteristics. Then, by comparing the results with the static elasto-plasticity analyses, the effects of amplification of wooden part and eccentricity are verified, and the consistency with the horizontal load-carrying capacity calculation, such as the setting of the structural characteristics factor DS, is confirmed to form a concrete background for the design of horizontal wooden structures.
The recent years have shown the demand for Cross-Laminated-Timber (CLT) with high stiffness and strength for use in CLT for walls and floors of mid-rise buildings. Moreover, the partial compression performance parallel to the outer layer grain of these layer configurations and strength grading is unclear. Partial compression performance is an indispensable material property for the construction of CLT structural analysis models. Therefore, this study reports the results of a compression test and the partial compression parallel for the outer layer grain test of an S90 5-layer 7-ply CLT in consideration of compression rigidity and the effect of additional length.
After a large earthquake such as Nankai Trough Earthquake, it is important to quickly and quantitatively judge whether the disaster base office buildings are safe or not. In order to realize the judgement, it is necessary to estimate the relationship between the story deformation angle and the damage estimation index considering the structural characteristics of buildings. The objective of this study is to propose the method for constructing the damage estimation index and to verify its accuracy. It is shown that the proposed damage estimation index based on the plasticity ratio is in good agreement with the actual damage.
A staggered pre-cast RC wall system is proposed. The system can provide the flexibility of interior spaces and simplifications of constructions. To investigate the structural properties of the system, experiments using scaled specimens were carried out with varying the vertical load acting on the wall. The experimental results showed that the load capacity of the system could be evaluated by the sum of friction force on the connection area and dowel capacity of reinforcement bars. Non-linear finite element analysis was conducted, and the analysis was validated by the experimental results. The analytical results also supported the bearing mechanism.
Flexural shear properties of cast-in-place pile using low quality recycled aggregate concrete with vinylon fiber was examined. As the result, drying shrinkage cracks was generated in low quality recycled aggregate concrete cast-in-place pile. The load carrying capacity of the cast-in-place pile was increased by the vinylon fiver under flexural shear experiment. Both cast-in-place pile normal concrete and low quality recycled aggregate concrete, load carrying capacity maintained until final acting load.
In this paper, lateral loading tests were conducted on a full-scale RC partial wall with a shear span ratio of 0.5, and the relationship between the area of concrete spalling or loss and the chord rotation was derived from test results. Furthermore, the pre-trained DNN model was fine-tuned to generate a detector that can accurately detect and measure the concrete spalling and loss on the painted surface of RC partial walls. Finally, it was confirmed that both of them can be used to evaluate the experienced chord rotation from seismic damage photographs of RC partial walls.
A reconnaissance of steel school gymnasium damaged by the earthquake off the coast of Fukushima Prefecture on February 13, 2021 has been conducted. These gymnasiums were also damaged in the 2011 Tohoku earthquake, and have been repaired or strengthened. In the two gymnasiums, severe damage to non-structural components occurred again. It means that restoration to the original condition would have caused the damage to recur. In the other one, all of the additional braces for strengthening were fractured. It has the complicated structural system, indicates that how to repair or strengthen should be discussed more.
In-situ tests were conducted to examine the design service life of a steel-framed greenhouse composed of European components and situated in Sapporo city. Based on the measured force distribution, the allowable strength limit may be reached at a three-second gust speed of 24.5 m/s, which translates to a design life of 1.6 to 5.1 years, depending on the referenced design standard. The test bay deformed three times as much as prediction from elastic analysis. An analysis model that incorporated the flexibility of column bases and knee brace connections adequately reproduced the measured force distribution and deformation.
In order to investigate the effect of middle tie beams on confined masonry walls, we conducted experiments of test specimens in which the variables were brick strength and the presence or absence of middle tie beam. In this paper, we report the effects of each parameter from the results obtained in the experiment. First, the test specimen composition and the experimental plan will be explained. The experimental results are shown below. Finally, from these results, a comparative examination is carried out.
Turnbuckle braces buckle easily by the compressive load and the buckling deformation may lead to the damage of finishing material, plastic strain concentration and plastic fatigue failure. The authors have been developing a bracing system with a compression-free function using CFRP. This bracing system has a partially fibered CFRP to absorb the axial compressive deformation. In this paper, the mechanical characteristics of the braces system are investigated through full-scale tests under horizontal force loading.
In this study, we examined the possibility of VR space for education of the building design. We conﬁrmed that subjects’ scale feeling improved signiﬁcantly after training by VR outdoor space. We also found that large scales longer than 10 m had lower training effects than small scales shorter than 10 m, The result suggests that the binocular parallax may make difﬁcult to judge the length accurately in cases where there are long distances between the viewpoint and the object.
In this study, we focused on tatami. In this report, as the next study, we further improved the reduction of transmitted impact sound by the car-tire source and examined the case where the tatami mat thickness was reduced. As a result, we were able to realize a prototype tatami mat with a performance improvement of 4 dB by reducing heavy-weight floor impact sound level in 63 Hz band. The prototype tatami mats had a considerable impact mitigation effect of 27 to 32 G. It was suggested that it is effective to introduce the anti-vibration material into tatami.
Eight surveys were conducted on the lighting environment when mothers care for children requiring medical care at home during the night. Two cases turned on the ceiling lights, and the illuminance was about the same as before going to sleep. Others used only nightlights (2 cases), leaked light from the adjacent rooms (3 cases), and smartphone lights (1 case). Suction works were performed at 20 to 40 lx for ceiling lightings and 6 to 8 lx for leaked lights. We also investigated the quality of sleep and found that the quality was generally poor and needed to be improved.
To solve the problem of condensation on the metal roofs of station platforms, it is necessary to estimate the surface temperature of the metal roofs and predict condensation. Therefore, we compared the measured surface temperatures obtained from experiments using flat plates with the estimated surface temperatures calculated from ambient weather conditions to confirm the validity of the estimated values. In the folded-plate experiment, the relationship between the surface temperature and the occurrence of condensation and frost on the upper and lower portions of the square chevron-shaped cross section was clarified by determining the water vapor partial pressure.
With the relocation of the Wellness office, the performance of the old building and the new building was evaluated by environmental measurement and intellectual productivity survey. The correlation between the measured physical environment factors and the degree of satisfaction with the thermal environment was analyzed, and the factors affecting the degree of satisfaction with the thermal environment were identified for each winter and summer. It was found that temperature fluctuations and vertical temperature differences have a large effect on environmental satisfaction in winter, and temperature fluctuations and wind contact are important matters in summer.
The central air-conditioning system attract people’s attention because the thermal comfort can be improved by arranging the air outlets properly. Moreover, various blow out conditions may be adopted to improve the indoor thermal environment. In this research, simulation studies to improve the accuracy of CFD by Momentum method under various blow out conditions has been conducted. Firstly, the airflow distribution under each blowing condition was measured by isothermal condition. Then, the simulation method by Momentum method is proposed. In addition, airflow evaluation method of diffused airflow and oblique-blowing airflow are proposed. Finally, an efficient acceleration determination method is proposed.
This paper presents an insulation retrofitting method developed for nomadic mobile housing called ger, which is used by urban residents in Ulaanbaatar, Mongolia, to promote the shift from coal stoves to electric heating devices to reduce air pollution. Field surveys of current gers were conducted to ensure that the design and materials chosen were affordable with high market availability. The developed system was installed in a typical urban ger in winter to obtain feedback from residents and local stakeholders. The results of field measurements of indoor thermal conditions of a ger with and without retrofitting are reported.
A method to visualize and categorize temperature, precipitation and wind speed data nationwide using the past annual meteorological data hourly observed by AMeDAS was investigated. First, by imaging the annual meteorological data of AMeDAS, the features that can be visually read were organized. Next, based on the idea of a deep neural network, a concrete method for dimensionally compressing the imaged meteorological data using auto encoder was shown. Furthermore, process of cluster analysis of the results of dimensional compression was shown. Similarity of data between measurement points nationwide was visualized, and its validity was also evaluated.
As an adaptation measure to hot environments, this study proposes a cooling method that stores water inside a moisture permeable waterproof designed in a bag shape and promotes evaporation from its surface. In this study, panel made of a moisture permeable waterproof membrane was set under a tent, and experiments were conducted to verify its heat mitigation effects. On a sunny day in summer, it was found the panel surface temperature decreased by about 7 degrees due to evaporation, and the glove temperature under a tent decreased by about 0.5 degrees.
This study analyzes the input and output data inputted into the calculation program for the Japanese building energy codes and clarifies the actual status of the building envelope standard compliance rate and envelope design specifications for non-residential buildings. This paper reveals the compliance rate of the envelope standard, the relationship between the building envelope performance index and the energy consumption performance index, and the average envelope design specifications by building type and region.
In recent years, ZEH has been drawing attention as a house that achieves a net zero annual energy consumption. In the present study, an unsteady 48-hour CFD analysis in winter was conducted to visualize the thermal environment of Nearly ZEH-M. The results showed that Nearly ZEH-M had a good thermal environment, exceeding the recommended minimum temperature range of 18°C, even in rooms without air conditioner running. It was also found that even with high insulation performance, thermal environments differed slightly by dwelling unit locations.
The purpose of this study was to improve the indoor environment by relatively simple renovation of aged housing complexes. Renovation work was carried out in the actual housing complex, and its effects were verified from the viewpoints of indoor thermal environment, air quality, and air conditioning energy consumption. It was clarified that the thermal transmittance was improved and the heating energy consumption was reduced by 10 to 18% by constructing the humidity control material and the membrane ceiling with the heat insulating material.
The purpose of this study is to reduce the risk of heat shock by changing floor plan at house renovation for the elderly. By numerical analysis using the actual renovation models and analysis of the layout of sanitary rooms including corridors, the items for changing floor plan to mitigate thermal environment were extracted. As a result of analyzing the renovation models applied those items, it was confirmed that the room temperature of sanitary rooms rise and the reduction of the heat shock risk by the proposed index.
The purpose of this study was to clarify how to open the private house as a communication space for elderly people by through the investigations 15 private houses in Kyoto-city. The minimum sharing way to open the front room facing the road, to use the same toilet and entrance with the manager’s family. The more convenient open way for not only elderly people but also multigeneration participant is to offer the special room, toilet, entrance for participant. Considering the elderly people for physical stress, it is better to preparing to enter into open area in the house with shoes.
The purpose of this paper is to introduce a design method of environment-oriented house to optimize natural energy use such as natural ventilation and sun radiation throughout a year, by switching the combinations of several established passive design techniques as ‘Mode’. In this paper, according to the annual record of switching the modes by dweller with the measurement of temperature and energy, the cost of equipped architectural elements, contribution of workload by dweller, and the ratio of saving energy on air conditioning are evaluated as a reference.
In this study, a questionnaire survey of daytime serviced group homes for people with disabilities was conducted. The results showed that most of the residents with severe disabilities were physically disabled, and most of the elderly residents were mentally disabled. Also, people with mental disabilities were more likely to stay in the group home during the day. The condition of the buildings tended to be accessible regardless of the type of disability of the residents. In addition, there tended to be no rooms specifically designed for daytime activities. The capacity was larger than that of a general group home.
In this study, we clarified the actual usage of the community space “Pita Cafe” for childcare workers. The survey method is a meeting with the operator, an on-site observation survey, and a questionnaire survey to users. As a result, it was found that the workshop set up for the production for practical training worked really well, and the repeat use of childcare students was realized. It was also found that online dissemination of information on childcare is effective for childcare students regardless of whether or not they are used locally.
In this study, we focus on “Sumibiraki”, as a base for building diverse communities. The purpose of this study is to obtain basic findings on “Sumibiraki” cases. The survey method was a survey of the actual situation of PR activities and interviews with businesses. 1) The purpose and the way to interact with users and the community differ according to the architectural form of the case study. 2) It is considered necessary to select a space according to the philosophy and to plan and organize activities according to the space in the future live-work.
M junior high school practices original group learning called “the unit learning” for active learning. We clarified the actual situation of the class development in the school and analyzed it about the area of the classroom. As a result, we showed it is necessary to extend the area of the classroom for the round of inspection between the desks and the storage space, and the expectation of teachers to expansion of the width of the classroom suggests that the flexible classroom design that is different from the conventional dimensions is necessary for planning.
This study seeks to clarify the changes in the provision of snacks for school children after COVID-19 measures were implemented through interviews with facility managers and surveys of activity plans for the nursery room at the Chikuya Pupil Club in Matsue City. The following changes were seen in the snacks offered to school children after the implementation of COVID-19 measures: reduced numbers of types of snacks, provision of only individually packaged snacks, intersections of the flow lines in the room, and the stronger influence of the small room.
In reorganization of public facilities, there is no established method to get inhabitants’ consensus although it is the most important. This study develops the workshop method by case study in a largely merged city. The evaluation survey identified the need to share workshop objectives, importance of time allocation and discussion continuity in workshops, and the need to functional considerations in each room. Finally, we constructed a workshop flow model. In the first workshop they would discuss on from the whole to individual facilities, followed by facility evaluation and reorganization methods in next workshops. Then, the reorganization plan would be summarized.
A temporary occupation project collaborated with diverse entities, Les Grands Voisins (LGV), has been set up on a former hospital site in Paris, the 14th, pending the new construction work in the redevelopment project. Between 2010 and 2020, LGV served accommodations for vulnerable people and provided ateliers, offices and shops to creative businesses by re-using abandoned buildings. Furthermore, the performance of LGV influenced the redevelopment plan itself, which will preserve most of the existing buildings. LGV’s outcome suggests a strategic way of reorganization and management of surplus public facilities to build sustainable environment in population shrinking society.
Public facilities constructed during the period of high economic growth celebrated 50 years, and in each municipality, the long-term repair plan of facilities and the relocation plan of facilities are being reviewed. Furthermore, many public halls are entering the time of updating and renovation. The purpose of this research is to clarify the outline of facilities closed in recent years and the reasons for closing by conducting questionnaire survey and interview survey for facilities with closed public halls that are closed or scheduled to be closed. It aims to assist in the construction of measures for long-term use.