This report showed findings of ready mixed concrete in Shimane. This investigation was performed with a questionnaire, and the recovery was 91%. A summary of the result is as follows. (1) 88% of coarse aggregate are Shimane products (2) 98% of coarse aggregate are crushed stone (3) 60% of coarse aggregate are andesite (4) 60% of fine aggregate are crushed sand (5) There is doubt of alkali silica reactivity to some aggregate (6) In process control at the time of production, there is a difference between factories (7) Range between factories of the many fixed number in mix proportion is so big
Since natural sand for concrete is running short globally, due to the increasing influence of environment protection legislation, and because accessible reserves are dwindling, we are obliged to improve the quality of manufactured sand, and use it in greater quantities as a substitute for the natural product. However, producing well-shaped and properly graded sand also generates micro-fine particles as an inevitable by-product. In this study, the specific size range which has the greatest detrimental effect to concrete has been successfully discovered, and hence a method of using micro-fines most effectively can be proposed.
Seismic evaluations of existing reinforced concrete buildings have been extensive in Japan after the 1995 Hyogoken-Nambu earthquake. According to some reports, seismic evaluations found many RC buildings with very low concrete strength, i.e. less than half of the design concrete strength. It is important for retrofitting to clarify the mechanical characteristics of concrete from the existing reinforced concrete buildings. In this report stress strain curves of low strength concrete from the existing buildings constructed in the 1960s were investigated in comparison with concrete manufactured in the laboratory.
It is important to understand the content of the concrete force feed work and the pumpability beforehand to advance a concrete practice smoothly and safely when the concrete pumping method was adopted. A lot of researches on the concrete pumping method have been reported so far. However, the research that evaluates the working efficiency is extremely little. Moreover, the influence on the pumpability is not understood. In the present study, I conduct surveys of the force feed work and the mechanical efficiency of a concrete pump on actual construction fields. And, the numerical value that suits a present concrete pump industrial method is analyzed.
High strength concrete with specified strength of 150 to 200 N/mm2 using hybrid fiber as synthetic and steel fiber to improve fire resistance and toughness of concrete was newly developed. Effect of mixture proportion and content of hybrid fibers on properties of fresh concrete, toughness, bonding strength, autogenous shrinkage and compressive strength development under various thermal conditions were examined. Mechanical properties as toughness and bonding strength were improved and autogenous shrinkage were reduced by incorporating fibers. Compressive strength of more than 200N/mm2 on structural member and sufficient workability were confirmed by mock-up test and applied for an actual structure.
Methodology on the integrity evaluation in the aging management and evaluation of reinforced concrete structures was investigated. Problems on the durability evaluation of reinforced concrete structures were pointed out and an evaluation framework was considered. In order to obtain a rational evaluation, the relationships of the deterioration factor and year (F-t diagram), the material deterioration and deterioration factor (D-F diagram) and the structural performance and material deterioration (P-D diagram) should be cleared. Finally, the deterioration evaluation diagram (PDFt diagram) was proposed and a procedure of the integrity evaluation was indicated. The effectiveness of the evaluation using PDFt diagram was discussed.
Recently, the development of proper disposal process of construction wastes has been an important subject, and it is also required to ALC panel. In this study, it is examined the emitted conditions of ALC rubbles on construction sites. As a result, ALC rubbles such the shapes as a block or powder come to occur by cutting or scraping ALC panel, and the emitted volume of ALC rubbles was grasped in the feasible study on construction site. Finally considering the results of the survey and the feasible study, the material flow model of ALC panel was clarified.
This study describes the environmental impacts of lumber for building construction in Japan, focusing on CO2 emission. First, we collected the inventory data of several patterns of lumber with domestically-made or foreign-made using a case study approach based on some fieldworks. Second, we tried to estimate the volume of each and total CO2 emissions. Finally, we analyzed the issue of estimating method. According to the results, the patterns show obvious differences especially in transportation phase and kiln-drying phase. In addition, the emission coefficients have big influence on the results.
In this research, the carbon dioxide emission intensity of concrete-related industry is investigated based on field survey and discussions are made on influences of plant scale and regional characteristics. As a result, it is shown that the carbon dioxide emission intensity decreases with increase in the volume of annual production, because of the influence of productivity efficiency, and it varies widely at lower volume of annual production. And also the carbon dioxide emission intensity varies by the region depending on the distribution characteristic of plant scale, so that the carbon dioxide emission intensity in Hokkaido, where its productions are relatively-small, is higher than that in Tokyo metropolitan area.
This study was examined in order to clear the effect on color properties of external wall for the visual evaluation of one-sided corridor type apartment from the viewpoint on the value of color area ratio and color combination. The sensory tests were conducted by using the various color simulation panels of one-sided corridor type apartment. The appropriate color area ratio and color combination for improving the visual evaluation of one-sided corridor type apartment was cleared and proposed.
From the standpoint of the maintenance and management of ALC-buildings, the ability of ALC panel to be reused after being subjected to fire is likely to become an important issue. In the research described here, the adhesion in tension, compressive strength and bending strength of ALC panel after heating was studied. Moreover, the effect of strength recovery by spreading materials were studied. As a result, the effect of the strength recovery was confirmed.
In recent years, many buildings have set up eaves on an outer wall surface in order to control solar radiation. In case of snowy regions, eaves on building may be covered with snow. Consequently, the risk of falling snow and ice from eaves should be considered in such cases. The authors have started experimental studies of snow conditions accumulated on louvered eaves of a building. In the first, the laboratory experiment using artificial snow was curried out for clarifying the effect of member composing the eaves. Then, field experiments were performed to compare the accumulation of snow and its change in the three regions with different weather conditions.
This report presents the dynamic characteristics of two buildings of which structural systems consist of pre-cast concrete walls, connecting to reinforced concrete beams with bolts. One of the buildings was constructed 13 years ago and the other was newly constructed at the same site. Two buildings have approximately same dimensions. Array observations are done with seismometers in the buildings and the ground. Stiffness degradations by moderate earthquake were investigated in comparisons with dynamic properties of two buildings.
Damage detection through microtremor measurements was applied to two actual building structures in which walls and a beam were damaged artificially. The responses recorded in the time domain are transformed into the power spectral density matrix at each discrete frequency. The matrix is decomposed into a set of auto spectral density functions by the singular value decomposition. The changes of the resonant frequencies and the corresponding modal shapes are searched by comparing the state after damage with the state before damage. Structural damage locations are found through the largest change of the modal shape.
Seismic response of two high-rise buildings, 75m and 150m height, subjected to ground motions predicted for Uemachi Fault was investigated by numerical analysis to estimate plastic deformation demand on steel structural members. From the result, the inelastic response of the structure under Uemachi Fault was larger than the response of conventional ground motions. The maximum ductility factor and cumulative plastic rotation of the story and the plastic hinges at beam ends are obtained. These values are same or more than maximum response obtained from predicted long-period ground motions for Tonankai earthquake.
In this paper, we report on the design case with the steel rigid frame building that is faced to the elevated railroad of SHINKANSEN. The building is designed for habitable performance based on vibration test. As the results, the ground vibration by SHINKANSEN is confirmed that specific number of vibrations to depend on train scale and speed excelled. And, we report one example of the office building using the effect of the input loss for improvement of habitable. It is also shown that floor vibration can be forecasted by the simple simulation analysis.
To estimate the state of buildings, which have a seismometer, summaries of technical paper of an annual meeting from 2002 to 2008 are surveyed. As a result, 140 papers those are related to an earthquake response had been presented. Number of instrumented buildings is 119. Followings are major findings of this survey. 1) These numbers are larger than the result by the same kind of previous survey. 2) Buildings less than five stories occupy one third of the whole. 3) There are several papers that report wooden house response. 4) Most of the instrumented buildings are located in metropolitan areas.
In this paper, oscillatory properties of two school gymnasiums are investigated based on microtremor observation, forced vibration tests and seismic observation. The roof forms of the gymnasiums are different, one is a hip roof and the other is a gable roof. At each gymnasium, influences of the roof forms on the natural frequency or damping ratio, etc. are investigated. And using the observation and tests results, the validity of the dynamic analysis model is discussed.
Web-based geographical information system has been developed for understanding the damage of RC buildings in the Great Kanto Earthquake. Building damage data and analyzed results examined in the two investigation reports about the 1923 Great Kanto Earthquake in the City of Tokyo are included in the system. This system integrates various kinds of data such as damage data examined in old reports, estimated seismic intensity, newly observed micro-tremor data, old maps and digital elevation topographical map. This is useful for engineers to assist estimating the structural performance of historical modern architecture, and for citizen to consider the importance of disaster mitigation countermeasure.
This paper describes forced vibration tests and microtremor measurements performed at 4-story RC building before and after 4-walls were damaged artificially. The dynamic characteristics change is investigated using these measurements data. It is shown that (1) The damages can be clearly detected from changes of resonant frequency and amplitude between stories based on forced vibration tests; (2) The damages can be detected from change of resonant frequency, but that can not be detected from change of response magnitude factor based on microtremor measurements.
A simple method for estimating the seismic amplification characteristics of surface strata is proposed by using the response spectrum method within the capacity-spectrum design scheme. The following presentations and discussions are made in this article: 1) to compute the natural and equivalent site periods based on the modal analyses of the multi-degree-of-freedom (MDOF) soil systems, 2) to determine the effective shear strain in surface soil, and 3) to examine the reliability and accuracy of the proposed method compared to SHAKE analysis.
In-situ test of bearing capacity test at six sites were carried out on the steel pipe tapered piles. This paper presents the outline of the loading tests and results of the tests and so on. From the studies, it is found out that the tapered pile has the advantage of the straight pile in the vertical response.
Building No. 1, No. 2 and No. 3 at Nihon University were built in the almost same time, and those were made as the earthquake resistant constructions with four stories having the same structures and foundations. After construction, seismic strengthening, repair work for seismic isolation have been carried out, and those are now earthquake resistant construction, seismic strengthening structure and seismic isolation retrofit structure. Velocities by microtremor observation and vibration experiment by human power were measured by using the velocity detectors, damping ratios were calculated by the random decrement technique, and differences of those damping ratios have been considered.
This paper presents the seismic performance of wood construction with oil-dampers. Shaking table tests were conducted to evaluate a seismic behavior during moderate and severe earthquakes and shear wall test of oil-damper was also conducted to compare the shear performance with wood shear wall. As the result of tests, the shear wall with oil-damper reduced the maximum response by 20-50% and absorbed energy as twice as plywood shear wall.
In order to apply the results of microtremor measurements and construction site surveys to seismic diagnosis of contemporary timber houses, we investigate the relation between dynamic characteristics and seismic diagnosis. The main results obtained from these investigations are as follows. Timber houses having large translational frequency and damping coefficient, are estimated high quality from the viewpoint of seismic diagnosis. The torsional angle between upper and lower floors, and the torsional frequency of timber houses have a slight correlation with the grade of seismic diagnosis.
In these years, high-rise apartment buildings with core wall structural system have been constructed. Since span of coupling beams used in the core wall system is too short, large drift angle will be developed. However, RC short span beams do not have excellent ductility under high shear stress condition during earthquake. To resolve this problem, it was decided to use high-performance fiber reinforced cement composite SHCC (Strain-Hardening Cementitious Composites), which exhibits excellent ductility, for short-span beams. In this study, shear bending tests under antisymmetrical moment condition of SHCC beam specimens were carried out to investigate their structural performances. The accuracy of the calculated flexural strength and shear strength values was also examined.
It is often reported that the strength of the concrete cores from the existing reinforced concrete (RC) buildings were less than half of design concrete strength in the seismic evaluations. Those low strength concrete were also lower than the applicable lower limit of 13.5MPa in the Standard for Seismic Evaluation of Existing Reinforced Concrete Building in Japan. Though it is necessary to continue to use the existing buildings provided some retrofitting, the evaluation method for the low strength concrete have not been established clearly. In this research program the experimental investigation were performed to clarify the seismic performance of the RC member with low strength concrete.
This paper presents a beam-end damper which is developed to improve energy dissipation capability of the unbonded post-tensioned concrete structure. To investigate the damper effects, a cantilever beam with dampers was tested under reversed cyclic loading. The experimental results indicate that a high energy dissipation unbonded post-tensioned concrete structure is readily achievable. And a method of modeling the damper for nonlinear analysis is also presented. Comparisons of the experimental results and calculated results lead to confirm adequacy of proposed model.
The safety of Non-Engineered Construction is one of most urgent issues, because it is main cause of human casualties. Building Research Institute (BRI) and partner institute both in Japan and abroad have been working on safer housing since 2005. Various research and studies for Non-Engineered construction Activities have been conducted towards achieving safer structures. The confined masonry becomes common structure in earthquake prone area recently. This experimental study on confined masonry was conducted through full scale shaking table test in Japan and Peru. This study aims to better understanding the behavior under earthquake, and research for feasible and affordable seismic construction in earthquake prone area.
This paper is a study on deformation angles to doors located in entrance alcoves, which are regarded as a means of prevention from shutting residents into their units of apartment houses after an earthquake. The followings are pointed out by discussions on the deformation angles with considering both of floor heights and openings’ heights in walls: firstly entrance doors for middle-high rise apartment houses need more than D-2 grade of seismic performance. Secondary D-2 doors are enough for narrow types of alcoves. Finally D-3 doors are needed for wide types unless D-2 doors with transom windows are used suitably.
The experimental study on connection method of steel frame with brace is outlined and the structural performance of that is discussed in this paper. The purpose of this study is to develop the new seismic retrofitting system of steel frame with brace. Static loading tests were conducted for a total of five one-bay one-story retrofitted frames with the experimental parameter of connection details between the existing RC frame and the installed steel frame. The results showed that the lateral deformation capacity and the strength of that are controlled by the anchor bars.
Ultimate properties of seismic isolation rubber bearings under horizontal biaxial loading are investigated with scaled-model testing. It was observed that the high-damping rubber bearings was twisted by torque generated by damping factor under biaxial deformation, and showed shear-break in smaller shear strain range than in uniaxial loading. Additionally, finite element analysis (FEM) was conducted to simulate the twisting deformation and local stress and strain. The results showed good agreement with test results, and indicated the possibility of FEM as an effective tool for prediction of failure strain of isolators in biaxial loading.
Fire resistance of structures depends on the structural stability during a fire. If a fire occurs in a building after an earthquake, structural members would lose their stability earlier than the nominal fire resistance time because the fire protection would be damaged by the earthquake. This paper shows the deformation behavior of the fire protections which comprise covering with sprayed rock wool, calcium silicate board, heat-resisting rock wool blanket, and heat-resistance coating sheet in shaking table tests on a full-scale steel structure. As a result of the tests, the fire protections were little damaged about efficiency of fire resistive performance.
Elderly persons account for more than half the residential fire fatalities. The mortality rate is especially high among elderly persons who live alone, and they need to be coped with. Although the knowledge about elderly persons living alone has been accumulated from various researches, there is scarcely any about how they estimate their own risk of residential fire and diminish it. In this paper, we first identify the elements of residential fire risk of elderliness and living alone, and then we clarify their attitude toward residential fire from an investigation of interviewing and sketching their way of dwelling in their houses conducted in 1995.
Recently, post-set solar shading techniques for existing windows have been developed for reducing the air conditioning load. The optical and thermal properties of sixty-nine samples are measured according to JIS (Japan Industrial Standard) method. In addition, heat load calculations are carried out for the cases of office and house in Tokyo and Osaka. The optimum solar shading techniques can be derived from the load reduction performance curves obtained by the numerical simulation results.
Several researches related to airflow within wood-frame wall assemblies have been conducted in order to assess their hygrothermal behavior. However there are very few reports which investigate boundary conditions such as pressure difference and/or leakage area to predict the airflow rate through wall cavities. This paper describes the pressure difference that causes the airflow for vertical direction within the wall assembly. The pressure difference between the crawl space and the attic on an actual wood frame house were measured in the winter season. Additionally effects of several factors, such as air-tightness of connections of the wall, outdoor wind velocity, and temperature difference between indoor and outdoor air, were experimentally investigated. The experimental results finally indicated that the pressure difference can be approximately predicted using the temperature difference between indoor and outdoor air when outdoor wind velocity is less than 1.5m/s.
In order to optimize electricity generation capacity and determine the optimal attitude for photovoltaic systems installed in snowy areas, an onsite test module was installed and snow accumulation and electricity generation were measured. Snow accumulation on the module was only observed at installation angles of 45º and 60º. When installed at an angle of 90º, electricity generation decreased by approximately 20% during the snowfall season, increasing by a few percentage points during the summer at all three angles. Annual electricity generation only varied slightly between installation angles of 45º or 60º and 90º.
The authors compared the primary energy consumption and CO2 emissions of a condensing type gas water heater system with a CO2 heat pump water heater system for one year in Obuse, Nagano Prefecture, a location that experiences cold winters. The energy efficiency of the condensing type gas water heater system was 0.86, where as the CO2 heat pump water heater system’s energy efficiency was 0.68. The primary energy consumption and CO2 emission of the condensing type gas water heater system was less than the CO2 heat pump water heater system in three of the four seasons, except for summer.
We developed a calculation program for heating and cooling energy in residential house. By using this program, energy consumption of the heating and cooling appliances (room air conditioner, hot water heating system, FF heating system, central heat pump HVAC system and electrical floor heating system) can be calculated every hour from the input data such as the specification of the appliances, outdoor condition and pre-calculated heating and cooling load. This paper represents the overview of the program interface, input data and output data, and its calculation model, and shows the calculated primary energy as the example of the results.
In densely built-up area, the wind in the canopy layer is very weak, that causes the discomfort condition at the pedestrian level. In this paper, the possibility to improve the ventilation rate by changing the building height locally was investigated using the wind tunnel experiments. The ventilation rate in the narrow street was estimated by the mass transfer velocity in canyon wall that was measured by the originally devised water evaporation technique using filter paper. It was found that only small height change of wing-end building leads to the remarkable increase of ventilation rate over the whole traverse path.
We conducted a walking tour with citizens to experience and measure the urban thermal environment. This investigation was performed to make Klima-atlas with citizen participation by experience surveys. This trial was also performed to examine urban thermal environment from a new perspective based on comfort level (experience values) as indices for evaluation of heat island measures. This project provides an opportunity to raise awareness and increase understanding of the heat island phenomenon and its causes among local citizens. The results were provided to local citizens to create a good feedback loop to improve local environmental conditions.
The growth of Sedum increased rapidly with both investigation places for two months of the peak from the beginning of April to the end of May and reduced the growth after a peak for about 2 weeks. In addition, growth becomes dull when it becomes an over-humidification state by the long rain in low temperature period. The invasion of the woody weed was accepted other than Compositae and Poaceae plant with all places of investigation places. In addition, it developed that the propagation of the weed had an influence on growth of Sedum greatly. Escaping of Sedum happened in the University department of agriculture roof and spread a lot around a drain and the gutter that had abundant soil and water.
This paper describes performance tests of home heating equipments. The tests were carried out under an artificial climate chamber to evaluate thermal room environments and energy conservation performances conducted by several heating equipments. A new test method and a correction related to insulation of the test chamber are proposed for such evaluations. Test results are shown with comparisons among the heating equipments, and radar charts regarding five items are presented.
We studied the actual livability of annex-added housing built by Japan Housing Corporation. Japan Housing Corporation started to supply alpharoom-added housing in 1987, and in recent years, Urban Renaissance Agency started to supply annex-room-added housing as an improved alpharoom-added housing. This paper suggests these types of housing can create the space which offers the residents independence, flexibility, privacy, and so on.
“DOZO” (mud mortar storage) is one of typical Japanese traditional architecture, and some of them are effectively arranged and used in contemporary way. This research finds out actual situation of DOZO after earthquake disaster in Wajima city. Followings are major findings of this research; 1) DOZOs are originally built to be used for lacquer wear production, but now use varies, 2) DOZOs used for lacquer wear production and displays as well as other manufactures or business are tend to be repaired and used even after heavy damage, 3) people tend to feel attachment to demolished DOZOs, and so on.
This study has conducted a questionnaire with field work in Aomori, Hirosaki and Hachinohe city to find out common space’s utilization and snow measures of public housing during winter. As a result, five follows: 1) Corridor is effective as the place to keep Snow processing tool and to put the plant. 2) Garbage box at common space of outside is to keep away snow by residents. 3) Snow removal place is necessary to put snow and snow shoveling tools. 4) The problems of snow for the senior resident is the physical fatigue to clear snow.
This proposal is a planning approach of “Evaluation - Optimization - Management” to renewal the public elementary school as a nucleus of a new community by private initiatives. As for the Makomanai district in Sapporo, the population decrease and the declining birthrate and a growing proportion of elderly people in recent years are remarkable as well as other suburbs of Japan. Therefore, making the school size proper is being examined by the Sapporo city board of education. It is judged that it is proper to thin out two of four elementary schools in the district though a concrete plan has not been decided yet.
It is rare to present the play on the open stage in a public multipurpose hall. However, four theater types ( the closure and opposed fan-shaped and way line type ) are splendidly used in Osaka modern theater festival<Temporary theater>WA. If human egress and ingress is free from anywhere, the space is flexible, and the allowance of the space exists in the circumference of the theater, the open stage is the space which wants challenge for the performer. It was proven that the performer had required the open stage which does not stop in fixed proscenium theater which is opposed type.
This paper reports on the kindergarten user’s aspects of working and their needs for child-care based on the result of questionnaire survey at Tama-City, Tokyo. We broke users’ condition and conation of working (working types) and their consideration of working and social child-care from their children’s young age (consideration types) down into patterns. And guardians’ consideration to working and nurturing, the selection reason for the kindergarten, needs for social child-care, and the working conditions of double-income guardians were understood. As a result, it was pointed out that there was the necessity of social child-care or “Child-nurturing support” in the wide sense including the working style etc. to the kindergarten users that had been thought that “Child care” needs were few.
This paper clarifies life and the space in Swedish Förskola(Preschool). Following points emerged: 1) The number of preschools people in Sweden is less than that of Japan. 2) Children in Förskola have a lot of one person scenes, the place and time zone contain a lot of diversities. 3) The reason why the scene is a lot of, are i)the area per person is very large, ii) Arranging the room is various and iii)The child care stance where the staff sees various groups is taken. It can be said that the examination of “Area for each activity” is necessary for thinking about the child care environment maintenance at the future.