Many advantages of concrete using fly ash are well known. But, for buildings, the uses of concrete using fly ash are very limited. In this study, I investigated the mix proportion of ready mixed concrete using fly ash for buildings. As a result, I obtained the useful information for mix proportion of concrete. And, the characteristic of mix proportion of concrete was clarified by the equi-potential lines on compressive strength and carbonation.
For developing a technology to increase slag’s use in concrete, in this study, we mixed two kinds of slag fine aggregates in concrete: slag from municipal waste ash (WAS) and blast furnace slag (BFS) or ferro nickel slag (FNS), substituting partly for sea sand, to investigate the effects of multi-slag’s use and slag contents on concrete’s properties. It was concluded that multi-slag’s use doesn’t greatly deteriorate fluidity, air content, compressive strength, Young’s modulus and drying shrinkage, but reduces the carbonation resistance of concrete.
The flow speed of the fresh concrete was measured by the inclined flow test apparatus which is developed newly. Yield values and plastic viscosities were investigated from the result of the flow speed when the fresh concrete was considered as Bingham fluid. The characteristics of the mixing rate of the fresh concrete were expressed well by the value of the plasticity viscosity and the yield value.
In order to improve in concrete surface protection ability with retaining its low gloss, two types of silane penetrant (silane-1 and silane-2), one type of silane-siloxane surface coating material and the standard commercial penetrant were examined. The silane penetrants having different reaction speeds were individually coated on the concrete surface. The silane-1 deeply penetrated than the silane-2. However, the silane-2 which reacts faster than the silane-1 showed the excellent properties of preventing water permeability, carbonation and chloride-ion penetration. This is supposed that it generated steadier and thicker siloxane-bond network in the inner side of the pores of the treated concrete than the other. Treatment with both silane and silane-siloxane layers showed much better properties than a single treatment of them. The combination of the silane-2 and silane-siloxane layers gave the best durability to the concrete surface among the surface treatment materials. The gloss measurement showed that the specimens coated with the silanes had low glosses as same as the untreated one. On the other hand, the specimens with the silane-siloxane resulted having high glosses because of its own high gloss.
There is no case that examines conditions of a negligible repair of stone. This thesis examined the influence of the effect of the repair by the construction environment. The construction environment was assumed to be a cleaning condition due to the rainfall and dirt. As a result, the crack injection repair can be going to begin to be constructed in six hours. As for molding repairing materials, it has been understood that work can begin in three hours. And, as for the cleaning, it was confirmed that the air blow was effective.
This report deals with the effects of normal air temperature obtained from 3 measurement periods(1961-1990,1971-2000,1981-2010) on change of applicable period of cold weather concreting and maturity related to construction plan. According to the results of this study, it made clear that applicable period of cold weather concreting based on latest normal value is shorter than the previous period which are described in JASS5-2009. And maturity based on latest normal value is also bigger than the maturity based on previous normal value.
In this paper, the basic experiments aiming at the technical establishment utilizing IC-tags which performs information management of concrete were shown, when the IC-tags were thrown into the fresh concrete at mixing process. The durability of IC-tags against the mixing, agitating, and compressive strength of concrete were examined by the tests which we extracted as the most fundamental experiment. It was clarified that the IC-tags, which do not assume supplying to concrete, beard the various external force at the mixing and agitating process of concrete. Moreover, the result that compressive strength did not decreased was obtained when an IC-tag was installed inside concrete specimen.
A computer and trading slip assisted carbon flow calculation system was developed. The system is composed of a computer tool that can calculate the carbon sink and CO2 emission of wooden products. Carbon trading slips were used as to transmit information necessary to calculate the carbon sink and CO2 emission. Different amount of carbon sink was given to the wooden products originally from the sustainable forests and those originally from the non- sustainable forests. Case studies were conducted and the practicality of the tool was verified.
Color properties of interior finishing materials on the wooden schools in Noshiro, Akita were surveyed. Colorimeter was used for the measurement of material surface color and color values L*,a*,b* of interior finishing of 7 wooden schools were cleared. According to the results of the survey, it was found that the value L* of walls becomes low and a* , b* becomes high with the duration of building use. The value L* of floor was low with surface deterioration in long period of building use.
The purpose of this study is to increase damping capacity of bearing walls for steel framed houses. In this paper, a simple method using visco-elastic material is proposed for this purpose. Damping property is evaluated by full-scale test of bearing walls subject to dynamic and static load.
This paper reports a simple damage detection method applied to a building under an earthquake excitation. The structure is modeled as a single-input-single-output ARX model, which means only two measurements in each direction. The model parameters are linearly identified by the forgetting factor recursive least-squares algorithm. When the structure is damaged, its natural frequencies decrease and the corresponding damping ratios increase. The identification can understand the time of damage occurrence directly and the damage level indirectly. The applicability is verified by shaking table tests of a full-scale 4-story steel building at the E-Defense.
To grasp the effects of creep and fatigue characteristics on lead dampers under wind load, long-duration cyclic loading tests were conducted. From the test results, the lateral restoring characteristics of the lead dampers in the small deformation range considering the creep characteristics were obtained. Although cracks were observed in the lead dampers with cyclic loading, they had little influence on the restoring characteristics including the yielding load of the lead dampers. Analytical results using a simplified estimation method considering the small deformation characteristics of lead dampers agreed well with the test results.
To grasp the effects of creep characteristics and rising temperatures on lead rubber bearings under wind load, long-duration cyclic loading tests and real-time online tests were conducted. From the loading tests, the lateral restoring characteristics of the lead rubber bearings in the small deformation range considering the creep characteristics were obtained. Analytical results using a simplified estimation method considering the small deformation characteristics of lead rubber bearings agreed well with the test results. From the online tests, the response properties of a base-isolated building under wind load were experimentally verified, and the validity of the modeling approach for lead rubber bearings and the wind response analysis method were confirmed.
We performed a benchmark tests for the strong motion prediction methods using stochastic Green’s function method. In addition to the previous paper (Part 1), frequency dependent radiation coefficient of the source and oblique incidences of both SH and SV waves are newly considered. All the results calculated by four teams generally show good agreement to each other, although the analytical conditions are more complicated than the Part 1 paper. Since random numbers are used in generating time histories, synthesized amplitude shows variation in particular frequencies. When applying the stochastic Green’s function method, this variation should be in mind.
Strong ground motions have been observed at Tokyo University of Science, Noda campus, in Chiba Prefecture for more than 16 years. A velocity seismograph is installed and low trigger level enabled us to obtain a number of long period ground motions with long duration. This report describes outline of observation system and recorded motions, focusing on the recorded time. Site amplification characteristics of recorded motions are also discussed in terms of site amplification and group delay time. Long duration of the recorded motions is indispensable to evaluate long period characteristics of the ground motions more precisely.
As buildings have become higher, it is likely to find the wind loads that is equal to or even greater than the design seismic loads. Therefore, it is important to estimate responses of high-rise buildings under fluctuating wind force. This paper presents contribution rate of higher mode wind response of multi-mass system for high-rise buildings by using a modal analysis in elasto range. Then, it shows that the wind responses are usually separated into the low and high frequency components, and the wind responses can be expressed as sum of them. The agreement between the predicted value based on coupling of two components and results of time-history analysis was finally confirmed.
A friction damper with displacement dependent variable damping force characteristics was developed. The damper was designed to decrease damping force when damper displacement exceeded a predetermined value. Therefore, the damper is ideal for aseismic retrofit of existing skyscraper buildings in preparation for long-period earthquake ground motions expected to occur in the near future. Dynamic loading tests were conducted on a full-scale steel frame with a brace-type variable friction damper to verify the damper performance. The damper exhibited on-target characteristics, stable performance, and a high endurance capacity under cyclic loadings.
Information on damage of companies caused by the 2011 off the Pacific coast of Tohoku earthquake was collected by the use of released information, and the relations between the damage and JMA seismic intensity scales of the company location points were studied. The damage ratios to buildings and facilities increase with the higher JMA seismic intensity scale. Due to the tsunami damage, companies located in the coast areas such as material, energy, life and medical industries needed more recovery days than other companies in the inland areas such as electric, information, automobile, and machinery industries.
We performed a benchmark test for strong motion simulation methods using numerical methods (finite difference method and finite element method). We considered a four-layered model, a symmetric basin model and a slant basement basin model. All the results calculated by six teams from different institutions generally show good agreement to each other. We found minor differences of phase arrival time between institutions and minute differences between FDM and FEM for some models.
Following the 2009 benchmark test, we conducted a subsequent test for the strong motion simulation methods in more complex media, using various theoretical methods (the wavenumber integration method, the discrete wavenumber method, and the thin layer method). All the results show generally good agreements, but the results for damping media show discrepancies, especially in the fling step at very close stations to a surface fault. This is because the frequency-dependent quality factors violate severely the causality condition in the waveforms, especially at lower frequencies.
High load bearing capacity bored piling is a method that let achieve a large vertical bearing capacity by increasing the tip diameter and length of the pile. Therefore, in order to ensure the highest possible level of the bearing capacity, foot protection is important. While this method has remarkably improved the strength of foot protection, some problems related to execution still exist. Furthermore, although the bearing capacity of various piles developed by different pile manufacturers has been confirmed, such validation does not cover all grounds. In order to ensure a high-quality of construction, this report presents, based on grounds investigation, laboratory mixing tests, and pre-construction tests, a method for achieving higher execution as well as three quality assurance examples.
Bentonite grain in slurry, which is used for the construction of cast-in-place concrete piles, is attached on the surface of reinforcing bars by an electrochemical reaction of iron ions released from the bars. From previous studies, we found out that a dispersing agent is an efficient way to avoid adhesion. On the downside, when the amount of the dispersing agent is large, the aggregate in the fresh concrete may separate. In this paper, the properties such as bond strength and execution of pile were discussed.
Pulling test was carried out in order to examine the pulling out characteristic of permanent ground anchors of compression type having a large diameter settled in sandy soil. It was found that the level of the ultimate frictional stress was equal to the value of anchors which has usual diameter in the past, and the ultimate frictional stress was possible to presume by using the value of yield pressure in borehole horizontal load test, and the displacement of anchorage zone at the pulling out time was about 10mm.
In this paper, we present a new approach to calculate the horizontal load carring capacity of a wooden structure consisting of structural components with different deformation capacities. The conventional perfect elasto-plastic model is found to be improved by adopting a safety limit angle that gives the same potential energy for the individual components.
The drilling hole of the beam play a role in the adjustment between structural design and pipe design of mechanical system. This paper proposed a calculation way of the deflection of the beam with the holes, through considering finite element method, the spring model, and experiments. The proposed a calculation way was based on the mechanical model. The validity of the proposed a calculation way was confirmed by the experimental results and finite elements analysis.
The board shear wall set in frame was developed to promote regional timbers. Vertical arrangement of boards was considered for realizing narrow wall proportion. The basic type of test specimens as well as two other types of reinforced one by metal fasteners was made then their performance was verified by the full-scale tests. As results, it was found that these walls have sufficient stiffness, strength and ductility. Shear resistance factors were 1.0, 1.6 and 2.1 respectively. It was estimated tha the vertical arrangement of board cause advantages in shear performance due to frame proportion, anisotropic material properties and shrinkage ratio.
In this study, vertical cross piece made from hard wood was contained, the wooden shear wall composed of Japanese traditional elements was designed and the in-plane shearing test was done. The presumption of the moment resisting performance of the wall was tried by existing Inayama’s and Fukuyama’s formula. The stiffness, the yield load and the calculation value had good coincidence with the result of the test in the M-θ relation of each part, and it made it possible to presume on the safety side in the entire wall for the initial stiffness. The possibility of the wooden wall with high ductility and rigidity was shown by this development even if it did not rely on the steel hardware.
In this paper we conducted bending tests with steel-wooden-members connections and analyzed those strength. For these connections, we used glue-filled screw or lag screw bolt for the fasteners. Steel members are used for a foundation and wooden members are used for a column. Those connections were studied with the allowable stress design method for a small construction or emergency temporary building. As a result, it is confirmed that those connections are usable.
In order to evaluate the dynamic characteristics (natural period, equivalent viscous damping ratio, etc.) of traditional wooden frames, full-scale shaking table tests were performed. In these tests, the following types of specimens were included; 1) frame with hanging wall, 2) frame used non-slipping-out wedge, 3) frame installed Zn-Al dampers. Zn-Al damper and Non-slipping-out wedge were developed by the authors. As a result, horizontal displacement became from 27 to 37% smaller and equivalent viscous damping ratio became from 57 to 162% larger by using Zn-Al damper. Finally, seismic response analyses were conducted. Based on the static loading test, the hysteresis model of the joint part was made for analysis.
This paper shows that study of load ratio of mud-plastered walls and traditional construction frame, and attempt of the possibility of accumulation of strength of the elements. The specimens are composed of a traditional joints, and columns of alignment and number, Nuki of alignment, opening of height and width, and presence of Sashigamoi, etc. are different. The following results were obtained. 1) Strength Load Ratio containing Nuki very early is around 30%. But, Strength Load Ratio will be reduced to 15% 100rad. Then gradually increased, reaching 40% 1/15rad. 2) The ratio of Strength Load of Frame of the opening with Mud walls, larger than the wall No the opening.The higher the proportion of the opening increases.
This paper describes performance evaluation of a wood frame structure with seismic control devices using a visco-elastic damper based on the pseudo-dynamic analysis. The frame model of the structure is constructed for the pseudo-dynamic vibration tests validated by the experimental results. The energy absorption performance of the frames is evaluated in related with the effect of temperature and location of the brace connection at column.
In order to evaluate the seismic performance of the existing RC buildings, pull-out tests were performed to obtain bond characteristics between low strength concrete and plain round bar under reversal loadings. From the test results of the specimen without repair, it is pointed out that the maximum bond stresses were less than the allowable stress for long term load, in addition that the degradations of bond stress were apparently influenced by the loading cycles. The specimens repaired with epoxy resin injection showed a significant increase of the bond stress. The analytical bond-slip hysteresis rule was derived from the test results. Comparisons between the observed hysteresis loops and the analytical ones were performed.
Series of tests were carried out on reinforced concrete knee joints with/ without upper column stub to validate the anchor details of beam rebars and the stub size suggested in AIJ Standard of RC. The column stub was effective on the anchorage strength and the strut mechanism in case of larger than the half of the beam depth as recommended in the Standard, while it was not effective in case of the smaller stub. The 180 degree hooks only at the four corner of the stub top were effective, though the splitting failure could be induced due to the stress concentration.
The resistance mechanism of low strength concrete members was influenced by bond slip characteristics of the plain round bars. In this paper, the epoxy resin injection method is proposed to improve the flexural behaviour of those members. The experiments were carried out to clarify the seismic performance of those RC members repaired by the epoxy resin injection method. In the test columns after repair, flexural and shear cracks along the height of the columns were observed similar to the columns with deformed bars. It was confirmed that the maximum strength of the repaired columns agreed with the calculated flexural strength obtained by the present equation.
In seismic retrofitting of existing R/C buildings, indirect connection by post-installed anchors is used for the load transfer mechanism between existing building frames and steel braces or extension R/C walls. A new seismic strengthening method was developed using angles as shear-keys. In the indirect connection between the structural frame of existing buildings and earthquake resistance elements, shear force is carried by angles as shear-keys. Seismic performance of the frame strengthened by angles as shear-keys in the indirect connection was investigated experimentally. Based on the experimental results, the developed method was verified to be efficient for strengthening existing building frames.
The authors have developed the seismic retrofitting method by framed steel brace system partially and concentrically jointed with anchors to reduce the number of anchor. Seismic tests of four specimens with mansard type brace, installation method of column inside - beam outside, pin end hollow section brace and pin end double hollow section brace were conducted. The details of test results and design method for the framed steel brace system with them are reported in this paper.
Occasionally, in seismic retrofitting, the lateral load-carrying capacity is approximately estimated according to the guideline for the seismic diagnosis of gymnasiums. The approximate estimation method is very simple and useful for structural engineers. However, this method needs further refinement. Under the condition that large long-term primary load is applied, for example in regions with heavy snowfall, the position of plastic-hinges is different from that assumed in guideline. The purpose of this study is to propose a new set of considerations for the approximate estimation methods that use the guideline for the seismic diagnosis of gymnasiums.
This paper presents the remaining strength and plastic deformation capacity of the corroded steel member. They are confirmed by an experiment and analysis, about following two cases. 1) Tensile strength is predicted from calculated strength using the minimum of the section average thickness. 2) Shear strength of corroded bolted connection is predicted from calculated strength using average thickness on an expected breaking line.
We measure an axial strain of CFT columns of real buildings by optical fiber sensor, and compare an analysis result with a measurement result and analyze it. It was comparatively good about the dynamic axial strain of small amplitude, but it was difficult as a result of past examination. Evaluation of the influence such as the shrinkage behavior of the filling concrete of CFT columns was always hindrances of the conversion to column axial force from column axial strain by the dead load. We performed an experiment to grasp shrinkage behavior of the filling concrete of CFT columns from such a background. Furthermore, We performed loading test and considered influence of the shrinkage of the filling concrete.
The purpose of the investigation is to develop the automatic earthquake-proof device to be set at the openings of the building just before a big earthquake. The automatic device provides a receiver of earthquake early warnings of the Meteorological Agency. The earthquake-proof devices are set in the structure as soon as the receiver catches the earthquake early warning or the seismograph records the designated seismic intensity.
The clay wall, unapproved as a fire-protective material in Building Standard Low, has a problem of the building confirmation. Therefore, clay wall is required to be analyzed on its fire-protective performance. Since clay contains a certain amount of organic substances, it has a probability of combustion and heat releasing. This paper reports the fire-protective ability of wall clay, examining through the cone calorimeter and the gas toxicity, utilized as a means of the approval tests for fire-protective material have been carried out. As a result, the wall clay, even enriched straw, proved that it has a performance of noncombustible matter.
The PAC analysis is technique to estimate cognitive structure system using subjective similarity ratings and its hierarchical cluster analysis. However, that method cannot include one item in two groups. A wide common concept item will be included in either one cluster. Therefore I suggested a new method to form a cluster by overlap permission. I developed a support tool(PC software) and really applied it. The new method provided abstract concepts that ware equal to normal method.
In Meiji-era there used to be several thousands of wooden playhouses but nowadays there are only a few dozens of them left. We made field-studies on 15 playhouses and investigated the acoustic characteristics of these playhouses. In Edo-era, mainly Kabuki or Joruri were performed but after Meiji-era koto or shamisen concert came to be held in these places. The purpose of this study is to preserve the acoustic characteristics of these places as the form of the acoustic impulse response, and to seek favorable acoustic spaces for the traditional Japanese music in terms of the acoustic simulation.
This paper reports the outline of a new street lighting environment which distributed small intensity light sources. The amounts of luminous flux and consumption energy have got smaller than the previous street lighting, and the illuminance level on the street has also become low. The visibility around the street has improved by having installed lights in the vacant lots contiguous to the street. However, the possibility of danger and sense of insecurity originating in darkness were pointed out by the pedestrian. It was considered to be necessary to examine the negative factors about the darkness from different directions in the long term.
The concentrations of fine-particles and airborne fungi, the amount of mite allergen were measured before and after moving in the houses equipped with the air-cleaning system for the countermeasure against allergy. As a result, the concentration of fine-particles and airborne fungi in the houses for the countermeasure against allergy were lower than that of the houses before moving. Amount of mite allergens was also lower. The particle collection efficiency of the air-cleaning system was calculated from the measurement results.
An air conditioning system using ceiling radiant cooling panels and personal floor diffusers is designed. It is assumed that ceiling radiant cooling panels remove a cooling load and personal floor diffusers giving both air-conditioned outlet air and an air current feeling for individuals. The experiment facility for the system is constructed, and the thermal performance test and the thermal environment survey are performed. This paper reports the results of the thermal performance test and the thermal environment survey of the system, and shows that the system removes a cooling load properly and can provide the comfortable thermal environment for individuals.
A series of experimental study to investigate the bending strength and flexibility of steel sprinkler pipe through static loading tests, are carried out. These pipe systems don’t adopt flexible joints. To investigate the aging effect, aged pipes are tested and compared with new pipes. Moreover, to specify the service limit is lost due to leakage of water, the pipes subjected to load are filled with compressed air, and the air pressure is also measured together with the load and deformation. Based on the above experimental study, a simple way to approximate the failure deformation and load is proposed.
The purpose of this study is to make regional climate atlas in Osaka region for suggesting the pro-environmental urban planning. Three points were concerned; long-term analysis of urban climate, use of observed data and meso-scale numerical calculation and making method of regional climate atlas. For first point, the observed data was used and the calculation period was set for a month, August 2006 using WRF model. To represent the result of long-term analysis, the distribution of degree-hour and averaged wind speed and the wind rose were made. Consequently, the climate atlas represents the difference of the characteristic of urban climate.
In this research, we developed three table games for the purpose of easy study of meteorology by college students of building engineering. To verify the effectiveness of these games, we investigated the difference of understanding level between the two student groups; one had learned meteorology by the games, and another had learned with only textbooks. We clarified the effect of these games from the point of increase of satisfaction and motivation during the game time, and also of the decrease of consciousness of compulsory studies. The main factor of those phenomena was specified to be the moderate time length of their communications each other.
The penetration rates of several energy-saving technologies for houses from 2010 to 2050 were forecasted by means of questionnaire survey on Delphi method. The Delphi method is a forecasting method which relies on experts’ judgments. In this paper, ten kinds of technologies such as housing equipment for space heating and demand hot water, PV, HEMS and so on were investigated to the experts working on home supply. Investigated results of these technologies penetration rates should be useful to the development of scenarios for a Low-carbon society.