This paper describes the results of research study on carbonation rate coefficients of concrete using fly ash cement (type-B) in outdoor exposure test continued more than five years. As the result, the main conclusions are as follows. 1) The carbonation rate coefficients of concrete using fly ash cement can be expressed by the water-cement ratio. 2) The water-binder ratio has a good association with carbonation rate coefficient ratio. 3) The cement factor (α2) of the AIJ durability design recommendation can be calculated with 1.1 and the water-binder ratio factor (α3) can be calculated with (W/(C+F) - 0.304).
The influence of wet curing condition in early ages on the strength of concrete was studied in this paper. The concrete cured under 20°C and high-temperature conditions in early ages was discussed. As the results of both temperature conditions, the shorter wet curing period in early ages, the more water was evaporated from concrete. For the case of the shorter wet curing, the strength of concrete was lowered when some degree of the water evaporation was exceeded. The measurements of X-ray diffraction analysis show that the reaction of C3S of cement was lowered when the water was evaporated more from concrete.
This technique worked on development of technology to prevent the cracking occurs also in refurbishment layer of cracking the top by aging, in the case of adopting the pin net method on the outer wall that occurred through cracks. By typing an anchor pin in through cracks part, it was tried to reduce the cracking of the repair layer because of controlling the crack behavior of concrete. Experiment was performed from strength and energy absorption of the specification by the bending test of a small specimen. As a result, to type the T-forked anchor pin into the through cracks section revealed that can be expected to improve the adhesive strength at the crack and the flexibility to warping of the wall.
Recently, the development of proper disposal process of demolition wastes has been an important subject, and it is also required to the polyvinyl chloride pipe and fittings. The purpose of this research is to get basic information of deconstruction in demolition work of houses, and promote collecting and recycling of polyvinyl chloride pipe and fittings wastes. Then, the authors recorded deconstruction of 8 houses to clarify labor requirements, and the quantities and the state of polyvinyl chloride pipe and fittings wastes from demolition work were investigated.
In this research, it experimented in exterior wall diagnosis using the trial examination object which created the exfoliation part of the outer wall artificially for the purpose of grasping the tendency about the detection accuracy and the measuring limit of the defective part for every diagnosis method. As a result, the thickness of the defective part and the size of the defect, it will vary depending investigation techniques such as an infrared inspection or a test hammer inspection by an inspector, there is a clear difference in the extent of degradation diagnosis can be revealed.
This report is aimed at checking effect, and quality evaluation of the curing compound which are applied on concrete surfaces. In the experiment, carbonation and chloride permeability were measured on the concrete specimens with the curing compound where various conditions are adopted for hardened concrete properties. The effect which applies the curing compound is large with the shrinkage-reducing agent in carbonation resistance. Chloride permeability resistance is large in Silan impregnation. Next, it was examined whether rapid air-permeability speed could estimate the effect. As a result, evaluation of carbonation resistance is strictly difficult and that of chloride permeability resistance has not been performed at all.
Load combination of snow load and thermal load is studied using snowfall and temperature data observed at three cities. A load combination factor for the secondary load effect is affected by the ratio between the principal and the secondary load effect, the temperature at the time of construction and return period. The result of the study is compared with the result using Turkstra’s rule.
We detected ground springs and damping factors in a sway-rocking model using micro-tremor and earthquake records at a soil-pile-structure interaction system. We used an equivalent linearization method in order to consider non-linearity of soil ground. Additionally, we compared foundation input motion detected by observation data and FEM analysis. Finally, we made earthquake response analyses with the detected ground springs and damping factors to evaluate accuracy of the sway-rocking model.
This paper studies structural vulnerability of steel roofing and walls subjected to tornado-induced load. Using Finite Element (FE) method, the presented methodology will predict the successive stages of structural damage by a translating tornado. Wind pressure experimental data was applied to the FE model as the dynamic effects of changing pressures. The results of FE analysis show that the model case with a dominant opening is more vulnerable than the model case without it and extensive failure is observed under the maximum tangential velocity of 60m/s and more, which is consistent with past actual damage. The methodology described here will enable accurate prediction of tornado-induced damage to cladding of low-rise buildings.
This paper proposes an optimal method to select the damping coefficients and relief forces of oil dampers in seismic control buildings. The optimization method used is SPEA2 (Strength Pareto Evolutionary Algorithm 2) which is a multi-objective optimization method. This method was compared to the SGA (Standard Genetic Algorithm) using two plane frames for some representative design solutions. The proposed method was able to find solutions as good as or better than design solutions obtained by the SGA. Consequently, the effectiveness of the proposed method was demonstrated.
The sedimentary structure of the accretionary wedge adjacent to Nankai Trough influences on generation of the long-period ground motions. This study investigates effects of the accretionary wedge on amplification of the long-period ground motion in Osaka Plain by using the finite difference simulation for the 2004 South-east Off Kii Peninsula foreshock (Mj7.1). Amplification characteristics are discussed for plural locations of hypocenter and existence of sedimentary layers. Ground motion amplification depends on predominant periods of ground motions in rock sites, rather than simply whether accretionary wedge exists or not. This paper also shows effects of the thin soft layer along the Philippine Sea Plate on trapped waves from seismic fault, leading to large amplitude of ground motions.
In this study, fatigue damage of LRB in base isolated building under wind load during review period is evaluated with employing result of anamnestic cyclic loading test. Frequency of displacement amplitude is calculated from time history of displacement using Rain Flow Method. In this model, fatigue damage of LRB in the corner of building is the largest from the effect of torsional component of wind force. Due to frequency of accumulated time in low wind speed range, responses in this range have a large effect on fatigue damage of LRB.
A New base-isolation system, Hybrid-Rocking Column, is proposed and described. Several prototype scaled models are manufactured and tested. Static pulling tests are carried out and the behavior of the models was observed. The results of the tests and considerations especially on the effect of friction are reported.
An elevated station has a shed above a viaduct. Generally, sheds have extremely smaller mass than viaducts. In a mass-variable 2-DOF structure like elevated stations, large response acceleration tends to be raised on the upper story when seismic motions are inputted. In this paper, as a method of reducing the acceleration, we propose applying an inertial mass damper to its upper story. Through shaking table tests and analyses, it is shown that the large acceleration on the upper story can be reduced by the method.
In this paper, we report on the seismic response of an elevator-type High-Rise Mechanical Parking System (MPS) to be installed inside a high-rise building. First we show the analysis model that considers structural features because the MPS structure is supported by the building, and cannot stand alone. In addition to its beam-column joints, it has a pin structure, and the rigid floor assumption could not be satisfied. Secondly, we describe the results based on the coupled analysis of the high-rise buildings with MPS, and focused on the response of the palette upon which the vehicle rests.
The cast in place concrete pile with outer steel pipe is a pile enhanced earthquake resistance by using a steel pipe at upper of the pile. We developed the new type of the pile. The flat steel pipe and concrete are anchored by shear cotters mounted at end of the pipe. The ultimate bending strength of this pile is evaluated by the general superposition method which is considered the influence of anchor strength by the shear cotters. The proposal design method was applied to this test of some specimens which have different anchor strength.
The authors performed statistical analysis of the data obtained from vertical loading test conducted on 14 kinds of 256 screw piles which were applied to The Building Center of Japan. The effects of the position of wing (pile shaft or pile tip), the shape of wing (helical plate or flat plate) and the shape of pile tip (closed end or opened end) upon the end bearing capacity and the frictional resistance were discussed. And further, the effects of the wing diameter and the wing/pile diameter ratio upon the bearing capacity factors of screw piles were clarified.
This study investigates the pile damage effects on the seismic response of a base-isolated structure during soil liquefaction. Dynamic centrifuge tests are performed for a liquefiable soil and base-isolated structures with damaged and undamaged piles. The deformation of the base-isolated device is larger for the case of damaged piles than undamaged piles, which is well reproduced by the effective stress analyses using the 2D finite element method. Parameter analyses for various types of input motions infer that pulse type waves are crucial to amplification of response of the base-isolated structure with damaged piles, due to lateral large displacement from the surrounding liquefied soil.
The present study experimentally simulates and analyzes the damage of bearings in steel large roofs that was observed after the 2011 off the Pacific coast of Tohoku Earthquake. In this study, cyclic shear force is given to three models of slide bearings and four models of semi-fixed bearings. In the slide bearing tests, mobility is the first interest and in the semi-fixed bearing tests, damage and crush of base mortar are focused and the shear strength is evaluated according to the AIJ recommendation. In the Part1, the overview of the experiment and the behavior of slide bearings is described.
In this article, processes of the design and construction in an actual building made of bamboo are reported. The design and construction were required to be conducted so that it can be made by manual labor of students and volunteers due to the limited budget and materials right after the disaster of the East Japan Great Earthquake on 2011. To satisfy those requirements, bamboo which is supplied easily at near the site, was adopted as structural material, and handmade joint with enough strength was developed and the structural behavior and performance of this building were verified by experiments and numerical analyses.
In this study, lateral loading tests of shear walls with continuous footing foundation were carried out. The retrofitting methods used in this study were made by additional concrete casting reinforcing. It was found that the partial retrofitting by the additional concrete casting needed more than 1.82m length and reinforcing of column bottom end joints was also needed when the shear capacity of the added wall was high.
We developed the timber moment resisting frame of a single layer using drift pin joints. The timber moment resisting frame can be constructed by non-specialized machines. In reference to the past study, the moment resisting joints were modeled for the springs, and the rotational stiffness and the yield moment were calculated. The validity was considered by comparing the experimental results with the calculation results.
Bracing is one of popular shear walls for newly constructed and existing wooden houses in Japan. In our past study, it was clear that the shear performance without sheathing cover board is less than the design value of Building Standard Law. In this study, static loading tests for the bracing with sheathing cover board were conducted to evaluate the design value and shaking table tests for them were also conducted to confirm the design value. As the result of these tests, the design value of bracing with sheathing cover board is sufficient value of BSL.
A seismic strengthening method for Japanese wooden houses using corrugated thin steel plates is proposed. The steel plates are 0.5mm thick and screwed to the wooden frames. The plates cover the existing houses as exterior cladding and resist earthquakes. Behavior of the strengthened walls under lateral force is experimentally and analytically evaluated. The maximum lateral strength was observed as 16.6 kN/m under 5.5% lateral drift. Finite element analyses were conducted for the walls considering geometric and material nonlinearity of the steel plates and inelastic behavior of the screw connections. The behavior of the walls in the test was well simulated.
Static loading tests for timber frames with large hanging walls using dry-mud panels were conducted. Following results were obtained. 1) Failure mechanism of the frames is roughly classified into damage of the walls and breakage of the columns. If the columns of the frames were broken, bearing force of the frames is smaller. 2) If the columns of the frames were not broken, restoring force characteristics are varied by specification of the frames. 3) If the side of the columns in which was inserted the Sashigamoi was pulled, the columns are broken at about the half of the flexural strength.
A new system of the structural shear wall is proposed that it is hybrid structure with stack laminated timber panel and steel frame for buildings. It is remarkable conceptual characteristic that hybrid shear wall consists of steel frame and timber panel. Timber panel doesn’t resist of shear tensile force. The result of study shows structural behavior for seismic force, stress, stiffness and structural characteristic coefficient as the experimental study for the capable of application.
This paper focuses on the stiffness evaluation and the summation rules for the two-story timber frames, comprising of main frames and various aseismic elements, based on shaking table tests. The equivalent stiffness and skeleton curves for these elements are extracted based on system identification approach using acceleration response on several input motion. Summation rules are generally verified for the combination of main frames and other aseismic elements, based on assumption that the characteristics of main frames depend on axial force.
The author proposed the formulas for estimating the flexural ductility of R/C square columns and rectangular columns. However, the calculated values by the formulas of rectangular columns are not verified with tests result. In this study, tests of R/C rectangular columns with SD490, 685N/mm2 and 785N/mm2 class transverse reinforcement have been conducted under high compressive axial force. Based on these tests result, the accuracy of estimated ultimate strength and flexural ductility of R/C rectangular columns is clarified.
This report shows the results of an investigation by experimental study regarding the flexural loading capacity of slabs made of reinforced concrete and autoclaved lightweight concrete with vis holes for anchor. As a result, final failure patterns showed compressive failure of concrete of the compressive side for reinforced concrete slabs and shear failure for autoclaved lightweight concrete slabs. The flexural loading capacity of reinforced concrete slabs has shown almost similar with or without vis holes. On the other hand, the flexural loading capacity of autoclaved lightweight concrete slabs with vis holes was slightly smaller than that of without vis holes.
After a severe earthquake, it is necessary to immediately judge the safety of school buildings which serve as evacuation shelters. Focusing on school buildings with short columns, the column likely to fail first is determined from seismic evaluation data. A monitoring device is installed which sends warning signals when the column width enlargement exceeds a predetermined threshold. Two prototypes, detailed and simple, were evaluated through experiments. The detailed device can precisely measure deformation although it is expensive and requires more maintenance. The simple device is cheap and easy to install although a small error is introduced in the measurement.
One of the key limits of buckling-restrained braces (BRBs) is overall flexural buckling caused by connection failure, and they are required to exhibit stable hysteresis under cyclic axial loading with initial out-of-plane drifts simulating the bi-directional effects of a ground motion. In this paper, a series of cyclic loading tests with initial out-of-plane drifts for double web H type BRB and pin-ended tube-in-tube BRB are carried out, and the stability performance including various connection conditions and initial out-of-plane drifts are researched. These results are compared with the stability evaluation equations proposed by the authors, and the validity and accuracy of these equations are discussed.
Fatigue cracks of steel structural members applied by overload, repeated load occur. As a countermeasure, there are some crack repair methods such as Reinforcing plate method, Weld repair method, Stop-Hole method, and Mechanical repair method, and they are used corresponding to the characteristics. Among them, a mechanical repair method, is repair cracking, crack progress after the construction and effect of the thermal strains by welding can be considered to be less. In this paper, tensile test and fatigue test of the mechanical repair method are conducted to examine structural performance. These tests show fracture and mechanical properties of steel structural members and aim to be a basic data to propose fatigue design.
Pressure loading actuators (PLAs), originally developed at the University of Western Ontario, Canada, can correctly apply spatially-uniform, time-varying pressure on the surface of a specimen. Using this design, 4 PLAs were manufactured using components available in Japan with an updated control system. A detailed description of the development, function, and performance of these PLAs is provided, based on the results of tests with different testing conditions (size of pressure box, control mode, loading type, number of PLAs). Examples of their application in the determination of wind load resistance of cladding and components are also presented.
This report shows the results of an investigation by experimental study regarding the flexural loading capacity of composite slabs with reinforced concrete topped on the glued laminated timber panel. The shear connectors were used for deformed bar D10, flush cut bolt M12 and Lag screw bolt. As a result, there was no difference by three kinds of shear connectors for the initial stiffness, the proportional limit load and the maximum flexural load of composite slab when using glued laminated timber panel 60mm thick. The composite slab showed a ductile behavior after flexural yield load in load-deflection curves.
A comprehensive assessment system was developed in order to evaluate office workers’ subjective impression and productivity in their office environment as well as meeting space, rest space and outside space. Firstly this paper introduces the logic and the way with which questions were selected, designed as scale and presented in the web site. Secondly accumulated data was analyzed to show the validity of this system, using histogram of averaged evaluation of each question for each office. Finally it was found that evaluation construction of office productivity can be explained with evaluation of other spaces of building.
In recent years, sounds emanating from schools are increasingly being regarded as noise, and complaints about the noise are gaining attention. Therefore, a questionnaire survey was conducted to elucidate the sound environment situation around elementary and junior high schools. The survey was conducted on 3 cities in Nagano Prefecture (Nagano City, Matsumoto City and Ueda City) and 3 metropolitan cities (Yokohama City, Nagoya City and Osaka City). Comments on noise from neighboring residents were around 20-30% in the 3 Nagano Prefecture cities, and 60%, or about twice as much, in metropolitan cities.
Vibration energy harvesting has been studied as a candidate for powering next generation wireless sensor networks. It is difficult to harness the actual vibration because the amplitude and frequency are not constant. The combination of a vibration generator and an amplification mechanism, achieved increasing the amount of generated power in a wide frequency range. By using the new vibration energy harvester, sufficient energy was harvested from micro-vibration of the air-conditioning ducts to supply a temperature and humidity sensor and a RF transmitter.
It is important to estimate proper initial stiffness of seismic isolation device to evaluate effects of environmental vibration assessment. We examined stiffness properties of the seismic isolation device in infinitesimal deformation range by using dynamic lateral experiment results. It was found that the initial stiffness of seismic isolation device is 20 times the stiffness of the 100% strain. and that equivalent stiffness decreases rapidly when the strain is over 0.3%. Finally, we propose a simple method to estimate the vibration level of seismic isolation against excitation force inside buildings.
It is important to develop high performance insulation sash to reduce energy consumption in all over the world. Since energy is wasted as heat from window. Today, high thermal insulation performance window made from wood or resin has already been in widespread use in Europe. In this paper, we compare result from thermal insulation performance test of sash according to JIS A4710 with calculation about it with simulation software according to ISO 10077.
The seasonal shading correction factor had been used for calculation of PAL (perimeter annual load). When the energy efficiency standard was revised in 2013, new calculation tool of the seasonal shading correction factor was needed because climate zone is changed and simple tool is required. In this paper, basic logic to calculate the seasonal shading correction factor is shown, and the calculation method is verified. New calculation tool of the seasonal shading correction factor is released in the site of the revised energy efficiency standard for buildings (http://www.kenken.go.jp/becc/).
In order to clarify indoor climate in a crawl space after flooding, long-term experiment using a test house was performed. A second-story test house was constructed in a campus of Akita Prefectural University in 2003. In this experiment two rooms on the first floor of the test house and crawl spaces were used. Tap-water was supplied to 100mm depth on a crawl space in each room, and after 72 hours it drained. In this paper, indoor humidity and water contents of wood and concrete in a crawl space were analyzed from the view point of moisture balance in a crawl space after flooding.
This study aims, through a proposal and drainage performance verification of a new disposer drainage stack system applicable to kitchen drainage systems of super high-rise commercial buildings, to obtain knowledge which contributes to the planning and design method of such a drainage system. This report describes an investigation which was carried out on the system for one year after the tenants of the building started their businesses, during which time, how kitchen wastewater loads were actually generated, load-associated variations in in-pipe pressure and contamination of the pipe were observed, and verifies subsequently the effectiveness, safety and maintainability of the system.
The study aims to examine a super water-saving type toilet that uses less than one liter of flush water; significantly less than the upper limit amount of flush water specified by JIS (Japanese Industrial Standards), and develop and evaluate the performance of a drainage system dedicated for installing the toilet. A basic experiment is reported in the report, in which said super water-saving type toilet was used, on the assumption that the toilet was installed to a combined flow-type stack system, and the manner in which the drainage performance was affected and the securing of good carrying performance of the house drain were examined.
System behavior analysis and performance evaluation of solid desiccant air handling unit using polymer sorbent are conducted under various operation condition in summer. In this system, solar thermal and CGS is used for regeneration coil and well water is supplied to pre- and after-coil. The system performance is determined with not only performance of solid desiccant wheel, but also inlet water temperature to pre-coil and temperature maximum limitation of regeneration air.
The authors analyzed the low flow circulation ground source heat pump system, which has the variable water volume control in the primary side, in the office building. It is confirmed that the electric power of circulation pump was reduced as 85% compared to the constant water volume. The difference between the system COP including the circulation pump and the heat pump COP was small. Additionally, the effect of energy saving compared to the conventional air source heat pump system was 33%.
In order to determine the problems with introducing wood traceability systems, we did preliminary experiments in 3 areas: Nagano Neba village, Niigata Kamo city and Nagano Shinano city. As a result, we discovered problems with the data carrier and its attachment. In addition, it became clear that highly versatile traceability methods that can be used with various distribution forms are necessary.
Measurement & Verification (M&V) has been carried out on the effects of energy-saving measures that were installed in a high-rise office building. The procedure of the M&V was based on IPMVP. By using the field survey data and whole building energy simulations, the detailed actual building operation condition was assessed. As-built model was calibrated to fit to actual measurements. Then, calibrated baseline model was calculated using ASHRAE std. 90.1. Theses results were compared to understand the present status of energy savings. The energy evaluation shows that the energy saving of the building is about -41 to -43% of the benchmark building.
Energy and water supply services are important for life and business continuity and disaster recovery. This study presents an outline of the investigation about building power equipment, problems faced, and correspondence during the rolling blackouts following the power shortage after the 2011 Great East Japan Earthquake. The subjects of the study were approximately 100 disaster base hospitals, all of which have non-utility generation facilities in the Greater Tokyo Area. The results of this research provide a basis for future building equipment design for disaster mitigation.
The main focus of the study is to find out the actual energy use in electrified area and consider the way to improve it. First, actual energy use is investigated by questionnaire survey and find out the problem. Next, the potential of renewable energy such as photovoltaic energy and wind energy are investigated by actual survey. At the end a consideration for resolving the problem was made by energy conservation and introducing renewable energy. The study resulted to figure out a way to improve the energy using condition not only in the targeted area, but also in similar areas.
National Housing Authority of Thailand (NHA), which carries the supply of public rental housings, has been working on projects to solve housing problems for the low-income (Baan Eua-Arthorn), slum improvement projects, community housing projects, government personnel housing projects, special and community service projects, Rajabhat University projects, project for helping flood victims in the South and projects to solve economic crisis as housing development project. Public rental housings are included in community housing projects and government personnel housing projects. The public rental housings of community housing projects account for more than 90 percent and are concentrated at Bangkok Metropolitan Region. The public rental housings of government personnel housing projects are much distributed over local regions.