Cast-in-place concrete piles are likely to undergo high temperatures inside resulting from a rapid release of hydration heat, depending on conditions such as pile diameter, type of raw material and mixture proportion. In order to study the mechanical properties of cast-in-place concrete pile subjected to high temperatures at early ages, temperature histories of three cast-in-place piles with different diameters were recorded on site, and their mechanical properties under the outdoor environment were compared with those cured under the temperature controlled chamber.
The floor concrete of roof parking which passed 18 years from construction had been discolored to light straw yellow. The discolored depth of zone A was about 5mm, zone B was about 25mm. There was a big difference between the discolored depth of zone A and its of zone B. In order to consider the properties of each concrete and the cause of discolor, the examinations of neutralization depth, compressive strength, differential thermal analysis, diffractometry, pore size distribution and chloride ion amount were carried out. As a result, it was confirmed that the cement hydrate (C-S-H hydrate) who should have been stability naturally disintegrated by carbonation. And it was thought that the difference of construction condition and the difference of environmental condition and the concentrated chloride ion had caused the discoloration and had accelereted the carbonation of the concrete.
A local exposure test of concrete miniature models, which imitated the Prestressed Concrete Containment Vessel (PCCV), is being done in the Kansai Electric Power Oi Power Plant. The miniature are exposed to the environment identical to the actual PCCV's in a long term. The concrete of the miniature are tested to measure a compressive strength, an elastic coefficient, a neutralization depth, and a chloride content measurement, etc. to observe the changes of material properties. Ten years has passed and the durability and stability of the concrete model were observed by test results.
We developed the finish concrete surface method with high accuracy for the reinforced concrete condominium house, without "self-leveling method work". That was worked experimentally, and accomplished more than 80% of the accuracy target less than ±2mm.
Shrinkage compensating high fluidity concrete has been developed. It is a new type of concrete for construction joints which enables the joint to bond firmly in the inverse placing construction method. With the aim of examining the effective use of this concrete for construction joints a real size model, inversely cast with shrinkage compensating high fluidity concrete was carried out. Consequently, the test results were favorable.
In this report, I did a survey of transition of carbon equivalent in welding joint of a reinforcing rod. As a result it became clear that heat-affected crack occurred by decrease of carbon equivalent as execution a large amount progressed. Therefore, in the point of the site weld management, it is thought that the defect can correct it by making much of single V groove.
Using electromagnetic induction method, we tested the cover thickness of model specimens and examined its precision, as well as associated problems in detecting the reinforcement. As a result, we confirmed its applicability to the reinforced concrete structures. Furthermore, we applied the electromagnetic induction method to existing concrete structures and precast concrete components, where it was possible to evaluate the accuracy of reinforcing bar arrangement in a nondestructive manner.
This paper reports the results of accelerated test and outdoor exposure test on the repair performance on corrosion of reinforcing bar in salt containing concrete by various repairing materials. The results are following ; ・ The surface covering material has the protection effect of a reinforcing bar corrosion, with the part that is not repairing.・ The repair performance reduces it, if it does not do chipping the concrete of the periphery of reinforcing bar corrosion. ・ The primer has a repair performance in a section recovery area. ・ The repair performance differs by the type of a repair material, and the repair performance of polymer cement differs by the physical properties and the addition of inhibitor. ・ The primer and section recovery material recommend that uses the repair material of the same type. ・ The accelerated test is able to estimate the result in 1/12.4 periods of the outdoor exposure test.
This paper deals with experimental results on evaluation methods of flexural behaviors out of plane concerning about 2 types of stone facing composite panels with supports of truss structuring plate, truss structuring plate and metal for dry renewals of external walls. The stone facing composite panel with supports of truss structuring plate examined in flexural strength and evaluated by a criterion of more than 7 MPa in effective first cracked flexural strength. And the stone facing composite panel with supports of truss structuring plate and metal satisfied the various kinds of performances such as deformation, durability and waterproofness.
We analyze the seismic responses of soil-pile-base isolated structure system for variety of ground types under constant input motion. And we discussed the effectiveness of an isolation system on soft grounds using three dimensional effective stress analysis. Analytical results such as base shear coefficient and shear strain of isolator show that the seismic responses are reduced even on the soft clay ground and liquefiable ground. There is a difference in the acceleration ratios of building to ground, for the different ground eases. However, the response acceleration values of building are nearly the same levels for the different ground cases. We also found out that the response motions of the ground which is lower than the base mat level, are close to the input motion to the building base.
On-line strong motion seismic data acquisition system is developed and applied to existent strong motion and seismic intensity observation systems. Approximately 200 sites have been connected in Tokai district, which belong to local government, lifeline companies, universities and institutes. Some on-line connection techniques have been newly developed and used for existing systems with various hardware and software. Finally, some new aspects on network connection for strong motion observation are discussed.
Microtremor observatios have been performed in Sendai Area. The relation between depth to bedrock and peak period of H/V spectral ratio has been shown. Underground structures in Sendai Area have been estimated comparing theoretical H/V ratio corresponding to particle orbit of fundamental-mode Rayleigh waves with observed H/V spectral ratio. The validity of the estimated structure has been verified by observed ground motions in the Near-Source Earthquake on September 15, 1998. The maximum acceleration distribution for the Nagamachi-Rifu fault has also been predicted by using the estimated structure.
Viscoelastic damper, Vibration control structure, Earthquake response analysis, Nonlinear four element model, Voigt model Viscoclastic dampers (VED) have been used for seismic damage mitigation of building structures. However, it is difficult to treat VED strictly in the earthquake response analysis because the dynamic mechanical characteristics of such materials are affected by temperature, frequency and strain. This paper presents a simplified analytical model for earthquake response analysis of buildings using styrene-olefin viscoelastic dampers. It is concluded that the simplified analytical model could estimate the earthquake responses of structures using styrene-olefin viscoelastic dampers and the model is effective for design of vibration control structures.
Viscoelastic dampers (VED) have been used for seismic damage mitigation of structures lately. However, it is difficult to treat VED strictly in the dynamic response analysis because the dynamic mechanical characteristics of vicoelastic material are affected by temperature, frequency and strain. This paper presents the dynamic mechanical characteristics of styrene-olefin viscoelastic material STD1 and its analytical model. Temperature dependency of STD1 is smaller than that of GM1 which the writers developed before. So the effect of temperature on seismic response of VE-frame is investigated.
The topology optimization tools for the frame structures and the 2D. or 3D. continuum structures are developed in order to use for the architecture design education. The ground structure method is adopted for the topology optimization of the frame structures. The homogenization design method is used for the topology optimization of the plate and shell structures, and the density approach is used for the 3D. solid structures. By using such tools for the design education of the architecture, it is possible that the students acquire the mechanical sense naturally.
In order to understand the behavior of existing building having large open space, a comparison between the non-rigid slab assumption analytical result and the rigid slab assumption analytical result of existing building having open space is presented. The analysis result illustrates an increase in shear force share at frame without large open space. Therefor, the static analysis result illustrates a smaller shape index (SD) of the seismic screening method for existing building having large open space.
The purpose of this study are to know and to compare the shear strength of conventional dado and dove-tail joints with metal connectors system using LVL for timber structures by the experimental test. In this paper, we discuss the mechanical behavior regarding these 2 types of joints by the compressive strain inclined to the grain. Based on these experimental results, we propose a mechanical model for the calculation of the stiffness and strength in these connections.
Seismic damage, Brittle fracture, Strain concentration, Mechanical property Many steel frame structures in Kobe suffered severe damages during the Hyougoken-Nanbu Earthquake. Especially the large numbers of fracture were occurred at the welded beam-ends of beam-column connections. In this paper, on the 14 stories building we investigated, seismically damaged beam flanges of beam-column connections are analyzed to ascertain their fracture modes, strain concentration and mechanical property. Observation of the initial crack growth leading to brittle fracture, condition of strain concentration on the connections and comparison the base metal properties with the damaged metals nearby fracture section are discussed.
Fire safety design of shopping complex was carried out using performance concept. Safety of occupants and fire fighters, restriction of burning and smoke damage area were designed and verified against fire scenarios. Considering the huge size of the shopping complex, the whole building was divided into two parts by locating a large atrium in the center. The atrium works to confine fire and smoke effect within one of them. By adopting this design, fire safety strategy could be greatly simplified. As to the evacuation of occupants, non-fire side of the building is expected to be a temporal refuge area (TRA). As to the fire-fighting design, we provided two fire-fighting bases (FFB) in alternative direction from fire area. As to the fire and smoke damage restriction, fire is confined in 1/6 of one floor. To prevent the smoke from spreading to the other side of fire nor to upper floor shops, atrium is equipped with natural vent large enough to exhaust all the smoke. The structural stability was designed to prevent collapse during the whole process of fire to premise the above strategies.
PA (Public Address) system is usually installed and frequently used in multipurpose halls. But there are no standard indices for evaluating the effect of PA system on speech transmission quality. In this study a subjective experiment on "easiness of speech perception" was carried out with a simple PA system in a multipurpose hall. As a result, factors that influence "easiness of speech perception" such as characteristics of room acoustics, sound source, and amplified sound were presented.
In this paper, spatial distribution of heavy floor impact sound was measured at multiple dwelling houses and a steel house. At multiple dwelling houses, there was vertical direction of natural frequency in spatial distribution of heavy floor impact sound. Actually there was natural frequency in a steel house. But there wasn't vertical direction of natural frequency in spatial distribution of heavy floor impact sound at a steel house. Standard deviation of heavy floor impact sound level was influenced with natural frequency.
We have been made the construction of sound field simulators for hearing impression examination, and studied that correspondence between the sense of hearing and floor impact sound. According to the comparison of psychological scaling values between the multi-channel sound field and monaural sound field in hearing impression examination, in spite of some difference in evaluation depending on the sound field, the same trend is observed for two sound fields. We can show that the noisiness in auditory sensation is able to rate with A-weighted sound pressure level L_<Aeq> about heavy weight and light weight floor impact sound.
We made a sample with different surface roughness made of inflicting aluminum surface using sand paper abrasive and the centerline average roughness (Ra) was measured. The regular spectrum reflectivity from ultra-violet to infrared area (240〜15,000nm) was measured by spectrum photometer special UV-365 and IR-408, while total reflectivity from ultraviolet to near-infrared areas (340〜1,800nm) was measured by the integration sphere. The results were used to calculate the diffuse reflectivity. Their spectrum characteristics were also examined. Additionally the regular, total and diffuse reflectivity of visible, short wave-length radiation (sun-light), long wave-length radiation and emissivity were calculated by means of their measurements and were comparatively studied to characterize the influence of different roughness.
By using a spectrum photometer, spectrum reflectivity of building materials (metal and so on) which depends to be different in surface was found to have an intentional polish in near infrared area (210〜2,500nm) and infrared area (2.5〜25.0μm). This study is further examined the characteristics of surface roughness. Spectrum reflectivity was again measured with different coats (the reflectable paint, the general paint, etc.), which was in different surface of the building material. A comparison of the characteristics of the surface of separation of the change of the coat with the material was carried out. The results were shown that the spectrum reflectivity was mainly influenced by the different surface nature of the material. The influence of the paint on the surface of materials should be big on the spectrum reflectivity, and the characteristic with different surface of the building materials thus was clear.
In this report, the two subjects for elevating the availability of this method were discussed. (1) The velocity of balloons by the wind channel test was examined to evaluate accuracy of the measurement. It can be seen that the velocity of balloons was in direct proportion to the air velocity in wind channel, the inclinations of correlation line were more than 0.8 ; and the correlation coefficients were more than 0.9. (2) The automatic algorism to track balloons in pictures was developed to ease the operation of the measurement. And the algorism was useful as speed and accuracy.
In relation to the problems of Sick House, the field researches of indoor chemical pollutants in houses are increasing. But, there are few measurements about the houses of the patients have been pronounced of Sick House Syndrome and Multiple Chemical Sensitivity (MCS). Therefore, the measurements of concentration of formaldehyde (HCHO) and Volatile Organic Compounds (VOC) were carried out on 6 houses of Sick House Syndrome or MCS patients in Sendai. The result of this research is some houses are high concentration of HCHO and VOC, but otheres are not.
In assessing the performance of building thermal mass storage system, it is necessary to compare operations with and without thermal storage. Conditions vary day by day during a field measurement. Therefore, the comparison must allow for differences in the conditions, and its accuracy is questionable. As a solution to this problem, we propose a statistical method, which calculates the constants of assumed equations relative to heat and temperature through a regression analysis. Application of this method to a field measurement shows a charging ratio of approx. 0.9, and an effectiveness of building thermal mass storage of approx. 0.7.
This study aims at the development of water-saving faucets, as well as the establishment of their evaluation methods. A faucet that can involve a large amount of air in the washing water, aiming at the saving of washing water, was developed and the effects of water-saving were generally evaluated by investigating its handle feeling, washing power, and the water consumption in public toilets at railway stations.
We reported pupils', teachers' and near residents' evaluation on guide line proposals on creation of water spaces around this school in 1998 and 1999. This is a report on governments' reactions on the former subjects' evaluations. The governments were River Section of Asaka City and Saitama Prefecture. The reactions were arranged from 3 view points : environmental education, maintenance, cost. We compared the evaluations by citizens and governments, and clarified the supported guide lines of plan and design of the water spaces, and considered on probrems and solutions on guide line proposals of different evaluations.
To promote so-called eco-design, a simulation system was developed primarily focusing on to estimate outdoor thermal environment as visual schemes. Holistic frame of the presented system consists of two parts. One is the heat balance analysis at various surfaces of ground or buildings, and the 3-dimentional fluid analysis is another. Those two phases for analysis are connected effectively and unilaterally, the former to the latter. This system was originally aimed at the practical use by designers and engineers to assist their works. That's why this system is fully conscious of Graphical User Interface, GUI. One of the specific features is that the system includes quite a few hydrothermal properties such as various natural coverings, artificial soil surface, and green-covered roof, which were obtained by a series of experiments and observations of authors.
A well-insulated and airtight house with two generations including six family members was evaluated by a long-term measurement of thermal environment and energy consumption. The house, located in Sendai City (capital city of the Tohoku District), has a mechanical ventilation and space heating systems. The measurements were performed from November 1996 to February 1998. As a result, it was found that the indoor thermal environment of the house during the heating season was comfortable. However, the amount of energy consumption for space heating is relatively large, compared with other ordinary houses.Because the floor area of this house is large and indoor temperature in every room is stable at around 20℃ due to operation of space heating in all day.
A well-insulated and airtight house with solar water heating system in Miyagi Prefecture was surveyed relating with indoor thermal environment, indoor air quality and energy consumption. It was proved that indoor thermal environment at the living room in winter was good. But the temperature in Japanese room was relatively low, and HCHO and TVOC concentrations were high. Energy consumption was equal to the average energy consumption in Japan.
As a neutral academic institution, we introduce a new environmental model for interpreting the overall impacts of buildings and propose what can be done in a wide variety of activities in the architectural and construction fields. This proposal is based on the two-year discussion in the 'Subcommittee on Sustainable Buildings' of the 'Committee on the Global Environment' of the Architectural Institute of Japan.
This paper aims to examine spatial facility for respite care in nursing home. In order to understand that historical and present uses of rooms for respite care, it undertook an investigation for 30 nursing homes in Nara. The findings are as follows. (1) The room for respite care can be grouped into 3 type based on availability for users' 'private room'. 'Private room' was established by newly or when building extension. (2) In case of establishing 'private room', it is necessary to consider arrangement space, capacity and number of rooms. (3) In order to allocate room for cater for each user's needs, it is necessary to arrange reasonable number of respite care users. In case of not many respite care users, it is effective to provide each user to use a single room.
Interior/facilities system for multi-unit residential building, which can be installed easily by multi-skilled workers, was developed. This system is characterized by the prefabricated components, the integration of the facilities and the interior, and rationalization of the construction. In order to compare the work efficiency of this system with conventional construction, the efficiency measurement by a work-sampling method was carried out through the actual construction.Work time of the developed system was 3% more than that of conventional construction.
We arranged 16 layout patterns of light and dark architectural spaces and their 31 images by observation of various sun light spaces. We operated questionnaire experimentation to 29 architectural students using CG animations. We could clarify image structures of each layout pattern, and relations of spatial images, observer-movement images, and evaluation images.
The objective of this report is to study on relationship and network of functions in the surrounding area of amusement facilities. For the fundamental study of functions in the urban area network, we studied the basic data of economical and environmental circumstances. And to activate and animate the sourroundings area, we found it important to survey the railway and road network, and other functions. We evaluated the transportation, holes, convention centers and other activities, and researched wheter the infrastructures are enough for these amusement facilities. We put importance on the following items. 1) Research on transportation influence of amusement facilities. 2) Network of land use planning relationship and functions. 3) Impact study model in the wide area.
The purpose of this study is to clarify the process of social transformation in the historical city core in Lijiang, which is one of the World Heritages. The survey on residents and uses of the historical buildings were made and its results can be concluded as follows : In the process of tourism development, uses of the historical buildings built by indigenous Naxi-minority as residences have drastically changed and now over 50% of them are used for tourism industry. And 36% of the present residents of historical buildings are newcomers who came from outside of Lijiang.
The aim of this paper is to examine and clarify the procedures of soil cleanups and redevelopment process by undertaking case study of former factory and land fill sites in Germany. It also tries to find the effect and arising difficulties of newly introduced Federal Soil Protection Act 1998. Investigation methods used are interviews and site visits, and eighteen cases have been investigated. he results showed that due to the introduction of new law, it enabled to undertake investigation and cleanups at the national level, which leads to create the list of all suspected contaminated sites.
Former Coal fields, Treatment for land contamination, Redevelopment, Contaminated land, The U.K. The objective of this study is to investigate seven cases of land contamination treatment and redevelopment process on coal fields in the U.K. The research method used are site visits and interviews to local governments and government organizations. It is found that the contamination had a tendency to spread to wide area but low contamination, thus, treatment for coal fields is mainly done by encapsulation. It also found that it is necessary to cooperate within the local gevernment, in order to link land contamination treatment with redevelopment.
The purpose of this paper is to analyze the present condition of evaluation system in local government. It focuses on disclosure of information for transparency in the process of evaluating projects. In the process, a number of local governments disclosed information at evaluation committee stage. There are various opinions from the public, for example, technical problems and environmental problems etc. It is necessary to think about original evaluating items and views of the public in the real state of local government. For transparency, it is important to discuss in open meeting.
Agricultural lands for conservation in the urbanization promotion area is not utilized effectively for public purpose. This paper tried to propose new systems of transformation of land use and to make land use plan for earthquake hazard mitigation by public use. As a result, the registration for land use in case of emergency, rented land system are effective methods for land owners, local governments and the citizens.
Local beer companies were established both in Hokkaido and in the whole country after amendment of Liquor Tax Act in 1994. At the end of 1999, there are 32 companies in Hokkaido. Local beer contributes to revitalization of cities by reasons of topics, improving celebrity, gathering persons, being product effect, employment effect, economic effect and interaction among other facilities. There are several issues such as establishment of local beer culture, improving taste of beer, reduction of price, getting repeaters, sales network and restaurants with locality.