In order to use the fly ash reformed by flotation for concrete, the system to concentrate fly ash slurry from 10wt% to 65wt% in around 30 minutes is demanded. In this paper, we collected experimental data about cake filtration of fly ash slurry, and it was confirmed that cake filtration of fly ash slurry could be explained by Ruth theory. In addition, equations to estimate the optimum when fly ash slurry was concentrated were led. And a case study to design the concentrator of 10m3 in 30 minutes was shown.
The synergy effects of reinforcing rebars and Hybrid Fiber Reinforced Cementitious Composites (HFRCC) were experimentally investigated on the mechanical behavior of structural elements and on the cracking distribution. Uniaxial tension tests with prism specimens were carried out in order to evaluate the influence by changing the fiber volume content and the rebar diameter. As the result, the optimum combination to maximize the synergy effect of the rebar and HFRCC was found. In comparison with the influence of the rebar diameter, it was confirmed that the fiber volume content more influences on the synergy effect than that of the rebar diameter.
It was considered that the influence which the difference between a place of production and grading of silicate sand has on mortar quality and a permeability of the waterproof agent of cement for concrete construction. When the continuation grading of the silicate sand used, select the kind and grading of silicate sand. It was also found that since the amount of water permeability became unknown only by a water permeability ratio when evaluating water permeability, it turned out that a subject remains. It is necessary to select in consideration that the kind of silicate sand and grading to be used.
This study purposed for prehension about the actual situation of work from the viewpoint of formwork contractors. In this paper, we conducted a questionnaire survey about concrete form plywood, strength and rigidity of form, and formwork based on the experience of formwork carpenters in Kanto region. As a result, it elucidated the actual situation of work, concrete form plywood, strength and rigidity of form, and formwork in the construction site.
Concrete is recognized as a durable construction material and often lasts centuries. Therefore, waste from concrete buildings demolished due to some reasons must be reused from a life-cycle assessment perspective and to ensure effective recycling of construction resources. Concrete made with low-quality recycled aggregate can achieve sufficient quality to all requirements of related standards as a structural concrete, through the mixing design by use of the aggregate replacing method. This paper describes as to the mixing design and quality control of about 11,000 m3 of recycled aggregate concrete applied to main structures of a thermal power station scrapped and rebuilt.
We have developed a deep mixing soil having a blade shredding in deep mixing soil method. In this paper, the test was carried out in the ground with a cohesive soil. As a result, I found the following. 1) By attaching the blade chopped into excavating agitator, mixing performance has been improved. 2) When set at 260 rpm cut number of times vane, it was found that in the horizontal direction and the depth direction, coefficient of variation is less than 30%.
Deterioration of sprayed asbestos affects human health problems. To evaluate the deterioration, qualitative observations by trained engineers are common in Japan. The human health problems come from asbestos fibers emitted by shocks of air currents, earthquakes and so on. This inspires the authors a unique evaluation method; a given current velocity and quantity of air is applied to the surface of sprayed asbestos, and numbers of emitted fibers are counted. As a result obtained at 11 buildings, the number of fibers is well coincide with the conventional observation method. This may show possibility of quantitative observation using the new method.
In a disaster, temporary houses are generally constructed by lease. On the other hand, in the Great East Japan Earthquake Disaster, because a large number of temporary houses were constructed, many of them were purchased by prefectures. So, it is expected these disposal to become a problem after the period of use. Therefore, focusing on project of removing and reconstruction of temporary houses in Fukushima, we investigated the actual situation and problem about deconstruction/reuse of them by field survey and interview. We expect survey results to be useful after the period of use.
Catalan vault, a historic brick vault construction method used mainly in Catalonia of Spain is characterized by thin and lightweight masonry construction. This paper cleared the characteristics and the construction techniques of the Catalan vault through the experiment of constructing a full scale floor type vault. The materials like bricks and plaster available in Japan could be substituted for those used in Spain. The important technical knowledge acquired in the experiment and the difficulty of construction were related to the first layer of the vault which bricks are united with plaster of Paris, and characterizes the unique vaulting system.
The reuse system proposed by authors is one of methods to reduce environmental burden in the structural field. As for reusable members, we take up building steel structures used for plants and warehouses without fire protection. These buildings are assumed to be demolished within approximately 30 years. In this paper performance of steel structural members of a gable frame is evaluated by non destructive test for reuse. First, profile of a gable frame and characteristics of steel structural members are shown. Next, tensile strength is estimated using hardness obtained by non destructive test. Weldability is also estimated by carbon equivalent and weld crack sensitivity composition, measuring chemical compositions by non destructive test. Finally, the material of steel structural members for reuse is estimated as a result of tests.
During the 2011 off the Pacific Coast of Tohoku earthquake, most super high-rise RC buildings constructed in the metropolitan area had suffered severe shaking, leading to variation of dynamic properties due to structural damages. This study describes the damage estimation of the super high-rise RC building during the main shock using the 3D frame model. Their varying dynamic characteristics are discussed based on the system identification method. The dynamic properties during aftershocks are also investigated in view of the residual seismic performance after experiencing moderate-level structural damages.
A new sub structure-based damage detection method is proposed in this paper to locate local damages in a structure. The method assumes a dense array of sensor instrumentation to a structure to enable damage localization in structural member level. The performance of the method is demonstrated using numerical simulation data sets obtained from seismic response analysis of a three-dimensional 5-story steel structure frame model which has artificially damaged beams and columns. The proposed method successfully detects and locates the structural member level damages in the structure.
A simple and easy-to-use structural health monitoring system for a quick inspection of structural health just after large earthquakes is developed. The monitoring system consists of a displacement peak hold sensor and a wireless data acquisition system. The peak hold sensor is able to memorize maximum, residual, and cumulative displacement of structural deformation without any external power supply. The monitoring system has been already applied to over 20 buildings, and some of the systems verified its effectiveness at the large earthquakes, such as the 2011 off the Pacific coast of Tohoku Earthquake.
To grasp indoor damages of super high-rise residential buildings during the Pacific coast of Tohoku earthquake, the height distributions of real damages to interior materials and nonstructural components were investigated based on the repair lists and questionnaire survey. Then the indoor damages were compared with the interstory drift angle of the buildings assessed by the simple presumption method based on the strong motion data recorded at the buildings during the main shock. Consequently, the number of damages at the lower stories were greater than the higher stories. Then the damages tend to be greater with increasing the interstory drift angle.
Thin layered element method (TLM) is an efficient way for computation of Green’s functions. However, it requires unbounded domain represented by an absorbing boundary or layer. A perfectly matched layer (PML) is one of the highest accuracy techniques to absorb outgoing waves from a bounded domain. In this paper, I apply the PML to the TLM in order to improve calculation precision of elastic wave field in a layered half-space. The accuracy of this method is examined by comparing its results with theoretical solution. It is found that the PML gives good results when compared to conventional method.
The authors have developed a No-soil-discharge cast-in-place concrete pile method. The working steps of the method are as follows, 1) Soil is loosened and pushed into surrounding soil by special drilling tool. 2) When the tool reaches the final depth, the tool is extracted and concrete is pumped through the hollow stem of the tool. 3) Installation of reinforcement cage into the fresh concrete. So the method reduces digging soil and performs high bearing capacity compared with previous methods. This paper reports an outline of the construction method and results of field tests.
The steel pipes with small diameter are often driven into the ground to support temporary scaffolds or fences. The steel pipe piles with tapered and closed end were developed to improve the bearing capacity. The tensile or compressive resistance of these piles was unidentified. We carried out the vertical loading tests of the piles. It was confirmed that the pull-out resistances of the piles with closed end were more than the twice the pipes with open end. It was supposed that the steel pipe pile with closed end extends and hardens the ground at the time of driving.
The controls of quality in the deep mixing stabilized soil methods are normally applied after the conclusion of construction, and depending on the results of tests, it is necessary to re-execution. In this study, it was examined the applicability of quality control methods on the compressive strength of deep mixing stabilized column by electrical resistivity method, comparing the resistivity ratio of 28th and third day age (ρ28/ρ3) of field column with the laboratory tests. In addition, by resistivity of 28th day age (ρ28) of the column and the laboratory, is possible to estimate the compressive strength of improved column.
This paper describes the evaluation of strength and stiffness of Sagekama and Tsutsumikominuki connections for traditional wooden constructions. By means of experiments of T-type specimens, thickness of Nuki becomes larger the strength of specimen becomes large. Comparing the experimental results and calculated ones owing to the evaluation equation for Hottatebashira, calculated values by this equation agrees well with experimental ones of mentioned above connections. The compressive stress and friction stress contribute to the strength and stiffness of connections. Using 0.4 for Sagekama and 0.3 for Tsutsumikominuki as a friction coefficient, we can evaluate the strength and stiffness of these connections correctly. In case of H-type specimens, by modification of this equation we can evaluate experimental results fairly well.
This paper presents the incremental analysis methodology for nailed horizontal diaphragm. This methodology utilizes the tri-linear slip model as the nailed shear joint. For the purpose of investigating the validity of the purposed methodology, the simulated results are compared with the experimental results. The results indicate the simulation result of the shear joint are almost same as the experiments. However the zigzag nailed shear joint has small deference between simulations and experiments. The reason of this deference is the influence from the structural elements except for the nails.
We have done simulation analyses using a distinct element method (wallstat ver. 2.0.1) for shaking table tests with a frame of a traditional wooden house and a wooden dwelling house. The simulation method can consider fall down and sliding at a bottom of columns. Force-displacement relations employed at the analyses were obtained by static experiments. Analytical method using a distinct element method could be analyzed accurately on traditional wooden houses and wooden house as a results of the analysis.
Recently, the numerical value and the technical information of the design are insufficient though an increase of a large timber construction is expected. In this research, a high load carrying capacity shear wall with thick plywood sheathings for the large timber construction was developed, and its static bearing force was confirmed experimentally. And the bearing force of the shear wall was calculated by using past numerical analysis methods. As a result, the development of the wall having the target bearing force succeeded, and the numerical analysis method could be applied to the high load carrying capacity shear wall.
The purpose of this paper is to propose the method of a wall clay mixed with bamboo fiber and to examine experimentally an application for mud walls. First, element tests are performed to grasp a relationship between a length of fiber and mechanical characteristics of wall clay. Second, full-scale static lateral loading tests are performed to examine the strength and the fracture mode of mud walls mixed with bamboo fiber.
A reconnaissance of steel school buildings damaged due to the 2011 Tohoku earthquake has been conducted by the Architectural Institute of Japan. This paper discusses the damage to roofs and non-structural components of the gymnasiums due to the earthquake ground motion. The damage of roof braces depends on whether the roof meets the demand of the seismic evaluation of gymnasium or not. Although the damage of non-structural components depends on the type of material and construction method, it has a certain correlation with the damage of structural components.
To estimate the seismic performance in the difference of the arrangement situation of the hysteretic dampers which have a lot of influence for the vibration control effects, it is necessary to carry out many time-history analyses. However, it is difficult to comprehensively understand the relationship between the damper arrangement and vibration control effect from only the time-history analysis results. This paper proposes the vibration control performance evaluation method based on the absorbed energy without using the time-history analyses. This method can estimate of the best configuration pattern of dampers, and it is very effective for seismic control design.
In order to clarify structural damage on school gymnasiums due to the 2011 Tohoku Earthquake, total 1611 of school gymnasiums in Iwate Prefecture, Miyagi Prefecture, Fukushima Prefecture, Ibaraki Prefecture, and Tochigi Prefecture were investigated. More than 70% of investigated school gymnasium were slightly damaged or not damaged. On the other hand, about 6% of school gymnasium built in or after 1982 were seriously damaged. Moreover, in this paper, structural elements damaged seriously in the school gymnasiums built in 1982 or afterwards were examined.
In this study, the repairability and recovery of damaged structural members are investigated experimentally. At first, test specimens which are damaged with local buckling or cracks are reproduced by loading test. Next, the damaged specimens with plastic residual deformation are returned to the original position. Finally, the loading test is done after the damaged areas are repaired. From the test results, the comparison and evaluation of recovery of stiffness, ductility and strength before and after repair are investigated. It is confirmed that ductility and stiffness of the repaired test specimens are recovered to the performance of original state.
The purpose of this paper is to propose a new concept of a deployable structure and to show its transformation process. This deployable structure is mainly composed of square panels which are linked by rotational actuators and deployed and extended by a link mechanism. Its fundamental unit is already patented in Japan and shown in an international journal. However, the previous paper shows only one-dimensional extension of the fundamental unit, where its two-dimensional extension method has not been shown. The present paper proposes its two-dimensional deployment method for construction of a flat structure such as a solar power satellite.
This report presents experimental and analytical study on progress to the falling down of suspended ceilings without seismic bracing, and the effect of earthquake-resistant connection parts. In the experiments, the ceiling showed high compression buckling stress, but its restoring force had slip-type characteristics. It represented that the factor of the falling down was unfastening connection parts, and the expansion of screw holes.
A separating construction consisting of steel beam and fireproof partition wall is developed. In the development of the construction, a full scale fire test and small scale fire tests are carried out in order to verify two performances. One performance is the interaction between beam and partition wall, and the other is thermal insulation capacity. As the result of tests, it is confirmed that the beam-wall interaction is not a problem, and that thermal insulation capacity depends on the temperature of beam. According to these results, a simplified calculation method of temperature on non-heated side of steel beam is proposed.
In this study, with the aim of collecting the quantitative knowledge about radiant heat controlled by trees, the experiment was conducted using the ICAL radiant panel that can reproduce the radiant heating of constant intensity. By using this experiment, we considered the correlation of the shape of the tree and the shielding effect of the radiant heat of trees. As a result, shielding effect of radiant heat by camellia was confirmed by experiments. That effect was especially observed to have large tendency near the trees. Transmittance of heat flux and the shielding ratio(1-φy) have almost the same value, it was confirmed by the correlation of transmittance of heat flux and the shielding ratio(1-φy). Therefore, trees shielding ratio is one simple indicator that assesses the incident of heat shielding effect of the trees.
A pharmacy is a place which needs a proper speech transmission performance for giving customers accurate information about medicine. In addition, in a pharmacy, it is important to take considerable care of conversation leakage, because the conversation between a customer and a pharmacist includes lots of the customer’s personal information. This study focused on the sound insulation performance of partition walls installed in the pharmacy. The partition walls at counters may effectively achieve speech privacy by using a sound masking system. In this study, three pharmacies in Tokyo which have different partition design and room acoustic conditions were investigated. Acoustical conditions were actually measured and the effectiveness of the partition walls on sound masking efficiency was investigated through subjective tests using a three-dimensional sound filed simulation system. From the result, it was clarified that the partition walls had an influence on the masking efficiency. Moreover, high quality of speech privacy is satisfied by contrived management of layout planning, improvement of partition walls and using the sound masking system.
Outdoor lighting design is usually carried out to clear the Recommended Levels of Illumination(JIS Z 9110). In contrast, this research tried to renovate the Miyashita Park located in Shibuya-ku based on the lighting performance design. Since the facilities were converted to barrier-free, strong lighting was no longer required to satisfy walk performance. Performances required for lighting were investigated first, and then a lighting experiment which examines arrangement of lights for ensuring the performances was conducted. As a result of comparing before and after renovation, by distributing the minimum lights which ensure the performance, the whole visibility improved and the consumption energy also decreased.
In this research, it is proposed that atmospheric heat load is mitigated by using heat treated wood material for exterior coating of buildings. The heat budgets of wood deck and wall panel, which are actually constructed on horizontal rooftop and vertical wall, were evaluated. Numerical evaluations for heat budget on horizontal surfaces with and without wood deck in the case of same solar reflectance are performed. As are result, surface temperature and environmental thermal load in daytime on wood surface tends to be large, and the heat storage of building in daytime is suppressed and the heat discharge in night is reduced.
About temporary house of disaster, bad residential environment was reported by many interview researches. This paper describes year-round physical residential environment research about earthquake temporary house in Sakae village Nagano prefecture. In summer, it has bad ventilation, and hot air pools in temporary house at night. In winter, surface temperature is low at ceiling and finestra, as weakness of thermal insulation. Capacity of exhaust fan comes short, and then condensation is confirmed. Because of majority of inhabitants fails information about air conditioning and ventilation, residential environment degenerate. The necessity of guidance about resident method is checked out.
This report describes a commercial disposer drainage stack system installed to an approx. 100 m tall super high-rise experimental drainage tower, and the examination of how large amounts of waste drained from the kitchen of the tower (kitchen waste) affects the drainage performance of the stack and the carrying performance of the house drain. The report also aims to acquire, on the basis of the experiment results, useful technical knowledge necessary for the actual planning and design of a disposer drainage stack system which is used specifically for real super high-rise buildings for the business use.
A conventional selection criterion of room air conditioners based on rated performance is considered suboptimal from the standpoint of energy efficiency. In order to help consumers evaluate energy performance, annual performance factor (APF) was introduced in the 2005 revision of JIS C 9612. However, APF assumes thermal environment of Tokyo, which makes regional deviation of APF remain unknown. In the present study, rated coefficients of performance (COPs) and market prices of year 2012 models of air conditioners are collected. From the collection, APFs are calculated at nine representative cities in Japan to quantify regional characteristics of APF.
PMV control system was applied for a ceiling radiation cooling/heating system utilizing groundwater as heat source/sink. System improvements including extension of the ceiling radiation panel and inverter control of pumps were carried out in the 2012. The research results in summertime cases are summarized below: 1) Indoor PMV values were settled in the range of 0.2-0.6 which was narrower than the previous year. 2) The power consumption of the pumps dropped to 1/3 of the previous year, and that of the whole system containing an makeup air unit dropped to 2/3.
Chiba University has participated the international solar housing competition called Solar Decathlon Europe 2012. This paper reports the design process and construction result of the proposal called Omotenashi House. Chiba University has been designing a net-zero-energy and food self-sufficient model since 2011 including insulation system, landscape, structural planning, PV system, natural and artificial lightings, and active and passive systems. Finally Omotenashi House has been exported to and reassembled in Spain in 12 days, and measured its high energy efficiency and electrical balance with low VOC emissions.
The present study intends to develop a method for analyzing users’ behavior in the service area of expressway by open/close log sensor attached to the toilet booth doors. This method clearly shows the uneven usage of the toilet booth, which may result in inefficient use of the facilities as well as a damage caused by concentration of usage. The reason of the user’s choice behavior was discussed by the layout of toilet booth and the visibility of the interior spaces of the lavatory viewed from the entrance.
This study aims to investigate to what extent current Japanese Montessori nursery schools embody the physical elements of the environment suggested by Maria Montessori. Based on these elements, a questionnaire was constructed and mailed to a total of 701 Montessori and non-Montessori nursery schools all over Japan. Replies from 95 and 192 schools (Montessori, non-Montessori, respectively) were analyzed. It was indicated that: (a) Montessori schools embody significantly more elements than non-Montessori ones; (b) Montessori schools maintain their policy of providing various sizes of tables and a special room for afternoon nap that will support children’s self-directed activities.
More than half of all children’s homes are established in Taisya, which incorporate Tyusya and Syosya. Here, Taisya is assessed in consideration of mutual support staff and space. Cooking and other housework activities are performed in small units, and Syosya here is assessed in terms of individual care and a home-like atmosphere. As downsizing reduces the opportunity for communication among different care units, it is necessary to establish common-usage spaces. In this context, partial downsizing is desirable for many institutions.
In Japan, aged population has been rapidly increasing. The small day care facility for the independent elderly is one of the facilities to support daily life activities of the elderly. The purpose of this study is to clarify the actual conditions of service areas of small day care facilities for the independent elderly in a city in Tokyo where public transportation system is well developed. A questionnaire survey was conducted in four small day care facilities in the city in 2003 and in two facilities in 2011.
We report on the design aspects and process of the Asia Zone of Sapporo Maruyama Zoo opened in December 2012, and in particular, focusing on the snowy cold region. We accumulated the zoological design perspectives and experiences since the beginning of the Maruyama Zoo restart project started from 2006. The project was advanced through creating a design guidebook for the zoological exhibition that promotes compassion towards animals and anticipation upon meeting them. The ideas of breeding staffs on the design were reflected to draw the characteristic behavior of animals.
To improve the “quality of rest” provided at expressway rest areas, we have worked out 111 environmental assessment items based on what we have learned from bibliographic surveys. The assessment items were compared and verified with the EURO TEST, which are the only expressway rest area assessment standards in the world. Verification results showed that many of our assessment items correlate with the EURO TEST and, therefore, we have confirmed their validity on the whole.
This paper aims at explaining the characteristics of changes of closed school in local governments due to the type classification of children number and closed school rate with the database about the children of every public elementary school, the establishment and closed school that is built diachronically from 1949 until 2011. In the first period, the correspondence to the increase in number of children was done by establishing new schools and closing branch school in the county districts progressed rapidly on second period. The number of children shifted to the decrease again, and after 2001 years, the streamlining of schools had been proceeded after the merger in forth period.
The idea that accumulating and making use of existing buildings as urban stock is spread to society by practice of continuing to use them. This project intends to be a flow of the model, which is required in recycle based society. Reviving low utilized building is not merely a renovation project, but an opportunity to form a new urban space contributes for shaping future society.
This paper is a study on acoustic environmental condition and visual environmental condition for Design-Indices of contemporary churches in Japan. We report 10 cases.; 5 cases are catholic churches and 5 cases are protestant. Generally catholic and protestant have different ratio of 2 actions; preach(preaching sermon by human voice) and recitation(music) Measurement of acoustic and visual environmental condition is discussed on time for preach(voice) or recitation(music), and the Conclusion is the evident difference of 2 types of churches; catholic and protestant churches.
Low-carbon society is being implemented by concrete action nowadays. In Japan Otsu, Shiga Prefecture, how to plant street trees (Roadside trees) that came out of new ideas, may reduce the heat island phenomenon. In this study, we found the method how to suppress the temperature of ground surfaces by using of fluid dyna-mation simulation. And then, the result of this shows the optimal solution to plant beautiful roadside greens in the sophisticated city.
This study aims to understand accessibility of residential area to daily-use local facility of elderly people, and clarifies the characteristics of municipality in Chiba prefecture. We estimate the number of people who can access to the nearest facilities on foot. Then by applying these data to cluster analysis, we classify municipalities into 7 clusters in which to describe their characteristics. If the population density decreases, accessibility of residential area to local facility becomes worse. Particularly, the characteristics of residential area relate to the proximity of clinic, community center or library.