This paper describes the results of study on compressive strength developments of fly-ash concrete in standard curing. The 28-day compressive strength of fly-ash concrete is reduced as the ratio of cement replaced with fly-ash. However, the compressive strength of fly-ash concrete increases rapidly since 28 days. On the basis of the above, I was able to suggest the coefficient S of the prediction equation of compressive strength of fly-ash concrete about CEB-FIP1990 model cord.
As for the conditions of building construction in Japan, the environmental impact of transportation on building materials and components would have been remarkable issues in addition to the natural resource depletion issues recently. In this research, regarding the huge amount of concrete aggregate which was carried into Tokyo metropolitan area, the demand-supply conditions and the carried distance from aggregate digging area were examined, and finally the environmental impact of transportation load by truck or ferry on aggregate for building concrete was evaluated by the amount of ton-kilometer values and the amount of carbon dioxide emission.
Houses of usual people in developing countries are very vulnerable against earthquakes. Authors have been working on this issue and conducting a series of experiments. We faced a big difference between structures of construction practice on sites and specimens for laboratory experiments. We assume that strength of cement mortar is one of the key issues which cause the difference. Therefore we implement comparative study on several specimens of cement from several countries with different circulation/storage conditions. We also implemented strength tests of specimens made under similar conditions of actual construction sites in developing countries. We find quality of different counties/manufacturer is not so significant. On the other hand, cement/sand ration, remixing and curing affects the strength significantly for increasing the strength on sites.
In this study, the uniaxial tensile performance of hybrid type strain hardening cementitious composites (SHCC) that contains two kinds of PVA fibers was clarified. Moreover, the influence on the ductility by the difference of the specimen shape and mixed volume of the hybrid type SHCC was examined.
This paper deals with the influence of external insulation and the setting time of these materials on the distribution of moisture content in concrete. In addition, the finish time of the interior finishing material is investigated in this paper. GW has high permeability for moisture. And, XPS and PF over concrete keep high moisture content in concrete. It was shown to delay in order of GW, PF and XPS at proper finish time of the interior finishing material.
It is known that the risk of the industrial injury according to the age of workers is high in the low age workers and advanced age workers. And it is clarified that one of the reasons of the risk of advanced age workers is high, is decrease of the physical strength of them by aging. Then, for about 1000 workers, we surveyed the relation between the age and physical strength of workers, and this report is a summary of the result of the survey.
About 95% of the total amount of wall paper is including the Polyvinyl Chloride in Japan. Polyvinyl chloride wall paper is durable. From now on, it is expected to increase the amount of waste. However, polyvinyl chloride make hydrogen chloride at about 190°C when it heats, and to form dioxin. Therefore I examine that I reuse it as a recycling board without separating the material of the polyvinyl chloride in this paper. In addition, I reinforce a recycling board with glass fiber.
Considering the environmental harmonization and long-term values of super high-rise housing in urban area,the appearance of housing would need to be maintained for a long period on the condition of attractive and good looking. This study was examined in order to clear the effect of color properties of external wall on the visual evaluation of super high-rise building from the viewpoint on the value of the color area ratio and the color combination. The sensory tests were conducted by using the various color simulation panels of super high-rise housing. The appropriate color area ratio and color combination for improving the visual evaluation of super high-rise building was cleared and proposed.
A two-story, two-span by two-bay frame was set up on E-Defense shaking table, and exterior walls made of ALC panels were attached to the frame with typical connection details. In a series of tests, seismic responses of a high-rise building were reproduced in the frame. First, damage of ALC panels in expected seismic responses (the maximum inter-story drift angle is 0.02 rad) was observed. The possibility that the ALC panels come off and drop from the frame was also considered in an ultimate deformation range (the maximum inter-story drift angle is 0.04 rad).
This report shows the wind force characteristics which acts on balcony handrails of condominium under natural wind condition. As the results, the large wind pressure force acts on the balcony handrails at the corner part, and uniformly distributed of the height direction. The mean wind force coefficient which acts on balcony handrails showed that it was possible to evaluate at the inclination of the straight line which envelops peak wind pressure force to the maximum dynamic pressure. It proposed the evaluation method of peak wind force coefficient of the balcony handrail which considered a phenomenon under the natural-wind for the design.
The system identification of the dynamic properties such as natural periods and damping ratios of four skyscrapers located on Osaka plains was conducted based on the observation records during South-east off Kii-peninsula earthquake September 2004 (M7.4). We found the dynamic properties in the large amplitude portions of response waveforms to be longer in natural period for all buildings and larger in damping ratio for a few steel-buildings than those in the onset and/or the terminal portions of response waveforms. The greatest coefficients of variation of natural periods in duration of response seismic motions were 2 to 4 percents for steel-buildings and 8 percents for a reinforced-concrete building.
The sliding bearings are used for lightweight structures instead of the laminated rubber bearings. In many studies, the frictional coefficients of sliding bearings are assumed as less than 0.1. However, even if frictional coefficient is about 0.2, it may be effective for a big earthquake(max. acceleration > 200cm/s2). In this study, the effectiveness of sliding bearings made of surface-treated steel plates is examined under different conditions with an eccentricity, a pressure, an input wave and others. The reduction effect of response is proved by shaking table test, and the frictional coefficients are identified analytically.
A tuned mass damper (TMD) using a rotational inertia mass has been developed to reduce vertical vibrations of beams and slabs subjected to walking excitations. The newly developed TMD is composed of a spring and a ball screw mechanism with a fly wheel. Vibration tests of a beam structure were carried out to show the effectiveness of the TMD using a rotational inertia mass and compare the test results with those of simulation analyses using a theoretical model.
In this paper, we study on the applicability of Discontinuous Deformation Analysis (DDA) to dry-masonry structures such as Angkor. Many parameters are needed for DDA and we used contact force as a precision index to set guidelines for some parameters, i.e. close-line setting inside of a block, penalty spring constant, and time step increment. We also measured predominant frequency of block systems composed of different number of blocks and simulated them by DDA. We found that a system of different number of blocks requires different penalty spring constant. With these fundamental studies, we are elucidating collapse mechanism of dry-masonry structures.
To investigate the environmental impact from the construction of foundation piles, we estimated CO2 emissions for several scenarios. We investigated emissions for steel pipe piles, precast concrete piles and cast in place concrete piles. The lower CO2 emission from piles which were developed in recent years was shown. The relative CO2 emissions of pile materials, which occupy greater part during foundation pile construction and of the number of floors of buildings were approximated using linear functions. In short, the possibility of estimating of CO2 emissions using simple formulae was shown.
To predict behavior of laterally loaded piled raft foundations on homogenous soil, two simplified design methods are proposed. One is the corn model method and the other is the theoretical equation method. The proposed methods give the average stress distribution of piles under a piled raft foundation. Although in the condition that pile pitch is narrow, the proposed methods tend to underestimate displacement of the raft, they give fairly good agreements with the hybrid analysis results of laterally loaded piled raft foundation behaviors.
The centrifugal model test with the soil-pile-structure system was performed for the dry Toyoura sand layer. In order to investigate the applicability of the seismic deformation method and the Chang equation as the prediction method, the pile response was estimated before the test. The time history response analysis was also carried out. The analysis result was compared with the test. It was found that it may be better to take into consideration the ground displacement caused to an earthquake for evaluation of pile response on the non-liquefying ground.
This paper presents the seismic performance of wood construction with brick exterior. Shaking table tests were conducted to evaluate behavior during severe earthquakes and shear wall test of brick was also conducted to compare the shear performance with wood shear wall. As the result of the tests, story drift during JMA Kobe wave was less than 0.5% which is the limit state of damage and no damages were observed in structural element. It is confirmed that target structure have enough seismic performance in comparison with normal wood construction.
The development case of high damping walls with workability, low cost, a small number addition and high damping performance is reported. The verification experiment of structural damping performance is conducted. And the result is reported as follows. (1) The maximum equivalent damping factor of the walls is 29%. (2) The maximum decreasing ratio of response displacement is 40%, and the ratio of acceleration is 59% in many full scale shaking table tests. (3) The contributory effect of stiffness on the response is cleared. (1) The decreasing ratio 51% of displacement and the 71% of acceleration were the contributory effects of the stiffness.
The purpose of this study is to clarify the influence of over-driven of nail to shear strength of structural wooden panels. It is said that the over-driven of nail decrease shear strength, however, there is no enough data about this problem. Therefore we conducted single shear tests on OSB nailed joints and static loading test of SIP shear walls. The following main results obtained by this study are: 1) Over-driven of nail decrease shear strength, though the decreasing rate is lower than structural plywood. 2) There is little influence of over-driven of nail to SIP shear walls.
The experiment of timber structures often extends to the large deformation area. However, an appropriate measuring method of large deformation is not in existence. We carried out the static loading test to the rebuilt timber truss bridge of the length of 36m. In this test, a three-dimensional measuring system that used wired displacement transducers was developed. The two kinds of vertical displacements obtained from transducers and a surveying instrument by numerical calculation showed almost good agreement.
The investigation on seismic evaluation of existing reinforced concrete school building made it clear that the earthquake performance in this building is scarce. Therefore, A plan was made to construct the seismic retrofit for this building. In this research, we experimented with joint of the floor slab in an actual reinforced concrete school building to verify the validity of the seismic retrofit. From the test result, Shear strength for joint has been understood and the seismic retrofit construction was executed.
A compression test for concrete-mortar-concrete specimens has been developed to investigate the compression behavior of the joint mortar between two ultra-high-strength precast concrete columns. A method for estimating the compressive strength from the strength values of constituent materials is proposed. Long-term loading tests confirmed that the joint mortar remains stable over a long period of time even under high stress. The compression test was also used as a joint mortar strength control test for a practical building. The test results indicate that the newly developed test can be used to obtain reliable strength test results under accuracy conditions of specimen fabrication and precise loading.
We installed the optical fiber sensor which could measure dynamic strain and static strain with high precision in order to identify difference with the result of analysis for structural design as a true building, and to specify the performance of the building. By the analysis of the measurement, building performance evaluation / structure system evaluation / construction quality evaluation can use it, and think that feedback to a future structural design, an estimate of the damage can use it again. By this report, we introduce technology to measure strain and technology to convert strain into stress and we show analysis until the present.
Concrete filled steel tubular (CFT) columns have become popular as structural member used for buildings. In the current standards on CFT structures, the scope of design formula is limited circular and square section steel tubes. However, not only these steel tubes but rectangular section steel tubes is used for CFT columns. In this paper, the design formula of rectangular CFT columns is specified. Furthermore, this paper discusses the several issues using rectangular CFT columns on practical design.
The purpose of this study is to clarify the basic characteristics of the fire smoke movement in the space of low ceiling and large floor. Authors carried out the tests about the fire smoke movement of fire source with large-sized full scale real room. The main findings are as follows; 1) the smoke layer is moved about 107 meters from the fire source and it spreads to about 3,190 square meters in case of small fire source, 2) the layer of smoke is formed in the upper space and the layer of air is formed in the lower space.
In this study, we analyzed the egress layout and evacuation schedule and the evacuation route map in a community assemble facilities. As a result, it has been understood that there is the evacuation route map as one of the problems of the egress layout and evacuation schedule. In the evacuation route map, it has been understood to have made only the half of the investigated facilities, and the content and the display method in the evacuation route map are various specifications according to facilities. And, in this study, the proposal of the evacuation route map is tried.
The authors had previously proposed a method of evaluating fire safety in office buildings, based on a combination of statistical data and survey data obtained from questionnaires. The fire safety performance of the building and the characteristic value for “Fire damage area and Fire damage area rate” as the damaged quantities, was analyzed to develop an overall simplified index for the relationship. In this paper, the approach is applied to factories and hospital/nursing homes to try and confirm the possibility of expanding the proposed method to these building occupancies.
Side corridor type classroom is one of popular layout in Japanese elementary schools. However recent learning/education style has many variations to promote creativity of students, the side corridor type one is not suitable for such requirements. Therefore open type classroom is applied in several schools to correspond various education styles. On the other hand, the open type one has a problem about noise from the next classroom through the open space and students cannot concentrate the lesson. This paper discusses the methods to relieve the sound problem based on the experimental data. In the experiments, the scale model is used to obtain basic data. The sound insulation between rooms and the sound absorption of walls of open space are examined with results of model experiments. The obtained data can be used to design acoustical environment in open type classrooms.
Prior to construction of facilities which should not be exposed to intense environmental vibration, it is advisable to measure in-situ vibration and verify design merit to meet the environmental criteria. We have constructed simple response evaluation technique with soil-structure interaction incorporated. This technique comprises dynamic spring evaluated for simple soil layers identified by micro-tremor array observation and foundation input motion by spatial integration of measured accelerations. An application to the real site reveals similar results to that of FEM with energy transmitting boundary.
In the conventional calculation methods for window thermal performance, interaction between window and building wall is neglected. Namely, the boundary between window frame and building wall is assumed to be adiabatic. In this report, two-dimensional heat transfer calculations between window frame and building wall were performed. The ranges of linear thermal transmittance for various window types and frame materials caused by the interaction were summarized based on the calculations.
In order to evaluate the effects of grass spots on mitigating urban heat-island phenomena, radiation and heat balances were observed on a grass spot and an artificial ground in summer season. In the daytime, the air and the surface temperatures on the grass spot were much the same as those on the artificial ground, but the downward conductive heat flux on the grass surface was much lower, due to the latent-heat consumption. The surface temperature on the grass spot dropped rapidly in the evening, and the air on the cold grass surface was cooled through the nighttime.
It is important to know how to balance the energy saving and the illumination environment in classroom for improving the condition of learning. This paper shows the influence of the eaves length and the diffusion of the window to heat load and the indoor illumination distribution in a school classroom. As results of numerical calculation, we show a possibility that illumination environment could be improved although the heat load slightly increased by establishing the eaves and addition of the diffusion instrument.
Recently, heat island phenomenon becomes remarkable in big cities, and different countermeasures for mitigation of the phenomenon are adopted. In order to proceed the measures effectively build comfortable stay space in urban area where land use is limited, it is important to understand the conditions of heat transfer in urban area and the physiology reaction in outdoor space. In this study, thermal environment at pavement of Midosuji street is measured and thermal comfort in the area is evaluated by subject experiment.WBGT index is applied for evaluation of sense of heat received from street area.
The evaporative cooling of the roof surface was tested in such a way that water was automatically sprinkled by a humidity sensor over a mock-up of a folded-plate roof of a factory. The test results that the temperature of the roof surface fell by 8.3 degrees centigrade and the room temperature by 3.8 degrees showed that the evaporative cooling was effective. The effectiveness of the system is also confirmed from the simulations in Tokyo that applied roof insulating materials 50 millimeters thick, as indicated in the findings that the cooling load is reduced by approximately 12 percent.
Cross ventilation has the effect on improving the comfort of indoor environment. However, this effect has not been clarified since it is difficult to artificially reproduce the same indoor air-flow as cross ventilation. We have developed a device that is able to generate the fluctuating air-flow of same properties as an air-flow of the cross ventilated room. The verification results of the device’s performance are as follows: (1)The device that combines a slider and a damper can generate the fluctuating air-flow similar to natural cross ventilation. (2)The properties of the reproduced air-flow virtually correspond to those of natural cross ventilation.
The concentration and performance of the information processing devices that make up these systems are increasing rapidly, and this has led to an increase in the heat concentration of Data Centers as well. For this reason, air conditioning systems for Data Centers must offer a high level of reliability to constantly maintain appropriate room temperatures. In this paper, we will use the previously proposed calculation method to conduct the following studies, targeting cases in which the systems have actually been implemented. 1) Simulation to grasp the reliability characteristic in the system. 2) Examination for introducing thermal storage equipment to an information processing room.
This paper indicates a heat source system which is installed in a totally electrified hospital built in April 2008. The heat source system consists of a high efficient screw type heat pump chiller with ice storage and another module type air cooled heat pumps. A ground source heat pump system is also introduced by using the foundation piles as ground heat exchangers. In this paper, seasonal and daily operation modes of the system are investigated. Measures for high efficient operation and energy saving in the whole system are finally proposed.
The mobile observation method of air temperature was proposed to analyze occurrence of heat-island, and was applied in the central urban area of Changchung City of China in August 2007. Four routine observatories were placed, and also two bicycles with which the GPS receiver and the auto memory thermometer were set on each handle, ran along the north and south course of central urban area. We discussed and modified the method of time correction to evaluate a time change of temperature on 100-meter mesh area of which air temperature was observed at different time. Our method might be predominance than usual methods from the viewpoints of practicality and accuracy, especially in the limited situation of device and period of research.
One example of the evaluation of Japanese cities from the viewpoint of a foreign country is “A natural hazard index for megacities” published by Munich Re Group, one of the world’s major reinsurance companies. Among 50 large cities from around the world that were evaluated, Tokyo and Yokohama showed an exceptionally high score by the index. It is necessary to consider such a report as a warning regarding the safety measures in Japan, to behave responsibly as the world’s second leading economic power. However, it should be noted that the content of the evaluation is limited.
The present paper describes a coupled method of CFD and heat balance simulation for predicting and analyzing the microclimate in the developed urban locations where void-brick walls with evaporative cooling effect were applied. The heat balance simulation is performed using the 3D CAD-based thermal environment simulator developed by the authors’ group. A methodology of data transfer between the heat balance simulation and CFD simulation was proposed in this study. In order to present the usefulness of the proposed method, a case study was carried out for quantifying the microclimatic modifying effect of the void-brick wall applied to a rest station.
NHL (Natural Hydraulic Lime) is a traditional building material in Europe. NHL has declined after popularization of portland cement, but recently, it has been revalued because of its durability and environmental performance. In this paper, various experiments were carried out to examine the environmental performance of NHL about thermophysical properties, absorption and desorption of water vapor, and gas adsorption capability. The results show that NHL has various good environmental performance and has a great deal of possibility as environment controllable building materials.
Cooling load of building can be reduced, when solar reflection of roof surfaces is kept to be high. Such high reflective roof is called as “Cool Roof”. The cool roof is also expected to be one of countermeasures of heat island phenomena, because cool roof reflects solar radiation and prevents heat storage of urban surfaces. The cool roof has a private benefit and a public one. The former is reduction of air conditioning cost and the latter is decrease of urban temperature. This paper focuses the private benefit which is depends on seasons and areas. The private benefit is difficult to be recognized precisely without special knowledge so that simple evaluation system of cool roof is studied in this paper. The system can inform the building owner of the private benefit, and they can decide to apply it or not appropriately.
This research investigated about conversion of bank buildings. To 2006 from 1996, eleven city banks merged into five and many branches closed or merged. As a result many vacant buildings were produced. Most of these vacant buildings had big spaces for entrance hall and reception desk and placed at the center of downtown, near the station or on the main street. This investigation is clarified how vacant bank buildings were converted.
This study has revealed some information that will lead to the useful improvement of outdoor space in community facilities. 1. Outdoor space can be classified into ten types. 2. The cooking room with the door faced the outside can be used comfortably, and the power and water supply in the outside can make it more comfortably. 3. Furniture in outdoor space can be useful for making the place to communicate. 4. Repairing outdoor space contains “renewing rooms and their equipment”, “enlarging parking lots” and “building up security”
The questionnaire survey was done to the kindergarten and the nursery school in the Japanese whole country, and the realities were clarified. It has been understood that the kindergartens are larger than the nursery school in the size of facilities and the number of people. Oppositely, the nursery school of the capacity fulfillment rate is higher. There is no difference in the size of the child care room for the same age children in both facilities. On the other hand, staff's dissatisfaction with shared space such as gardens and playrooms and 1.2-years old children’s care room size was shown.
This study took up the self-government centers in Korea as an IT global developed nation to get the plan knowledge for the maintenance of IT learning environment. Two kinds of their IT learning environment are the maintenance of the IT machinery for individuals and for the group. With the spread of IT machinery to general families and the increase in the demand for learning to use the software, the group use is more important. In the function conversion of buildings, by rebuilding the infill from the state of skeleton, the environment has the same function as a new building.
This study is focused on creative group works. Based on the detailed observations and recordings, we want to find the relations between working activities, results and satisfaction of workers. We put the camera array system on the ceiling of the workspace and took plan-like images of working activities at regular intervals and measured the movement of bodies and tools. This paper also reports on the method to visualize the movement of workers and tools based on the measured data.
The purpose of this paper is to report the reconstructing process of a existing non-conformed department store. Some results show as follows: 1) The problem of “building restrictions on roads” is solved by “substitution of road” and “city planning decision” which secures passage way. 2) As for the problem of existing non-conformed building, “excess of floor area ratio” and “incompleteness of escape stairs” are solved by treating exisiting building and extention building as a whole, although “lack of smoke exhaust equipment” is solved by targeting only in an existing building. 3) The contents of this case is not authorized under the present law by reason of the revision of law. In this case, it was possible because submitting the confi rmation application is just before the revision of law.
Historically, the term gentry comes from the Old French genterie1) referring to land owners of a certain social status. Urban gentrification however, is a contemporary term associated with a process of change in social network composition, demographics, land use, build structure and real estate price. While for some scholars gentrification may be linked positively with renewal programs, this paper discusses the social consequences of displacement and the use of Land Readjustment and other strategies by the local government of Medellin, Colombia through Integral Urban Projects (PUI). Partial results of the Impact Assessment Study IAS 2008, designed by the authors and applied through direct interviews with more than 150 families involved in the pilot project are included.