High strength mortar using coal gasification slag fine aggregate were examined. As a result, the higher the replacement rate of the coal gasified slag fine aggregate, the slightly higher the flow value of the mortar. And, due to the increase in the replacement rate of coal gasified slag fine aggregate, the compressive strength of mortar decreased in the high-strength region and increased in the general strength region. Furthermore, even under the condition that the replacement rate of coal gasified slag fine aggregate was 100%, it was possible to obtain a compressive strength exceeding 100 N/mm².

Grading control of coarse aggregates is important to secure the workability of concrete stably. In this report, the actual state of the grading of coarse aggregates was investigated with the existing surveys and the expression method was studied. At the result of study, modified Rosin-Rammler’s equation could be applied to express the grading of coarse aggregates, those are river gravel and crushed stone. Three experimental constants used in the equation were set and the important point of grading control was suggested in each grading.

High-strength concrete has been put into practical use by technological development of air-entraining and high-range water-reducing admixture and low-heat type cement, and has become widespread mainly in high-rise RC buildings. However, high-strength concrete with a low water-cement ratio and a large amount of cement has a high viscosity, so construction problems such as pumpability and finishability have emerged with its widespread use. Therefore, we conducted a questionnaire survey on the specific details of defects and how to improve them by modifying the mix-proportions, for construction problems such as transportation of high-strength concrete, placing and compaction, and finishing.

In recent years, ultra-high-strength concrete of 300 N/mm² has been used for precast members. The authors developed the ultra-high-strength grout that can reach the strength of 300N/mm² with heat curing at 90℃. In this paper, we report the experimental results of proposed heating methods for the precast member joints using heating sheets externally surrounding. With the target surface temperature of the heating sheets at 140〜180℃, the temperature at the center of the joint achieved more than 90℃, enough to obtain the designed strength.

The pipes used for concrete pump are generally made of steel, but resin pipes have been commercialized for the purpose of weight reduction. In this report, we conducted a pumping experiment using a resin pipe, and clarified the usefulness of the resin pipe and the pumpability when it is used. As a result, it became clear that the pumping pressure could be reduced by using a resin pipe. However, it was clarified that the resin pipe has lower rigidity than the steel pipe, and the deflection and deformation become larger during pumping.

This study investigated the effects of various factors on the applicability of static modulus of elastic to early determination by warm water curing at 40℃. As a result, it was clarified that even if pre-curing time, type of coarse aggregate, Bulk volume of coarse aggregate per unit volume of concrete and concrete temperature were different, static elastic modulus of concrete using various cements could be estimated by the linear equation.

This paper summarizes the results of a questionnaire survey of contractors regarding appearance of cloth for seams of gypsum board in interior finish. In this paper, the specifications for attaching cloth to gypsum board in JASS 26 were summarized, and then the matters of material used for partition wall, the matters of related to the gypsum board, the matters of apparent of cloth due to seams of gypsum board were clarified by a questionnaire survey of contractors.

We describe the study of the monitoring test using the full-size simulated models related to durability of coating and effect of surface coating of concrete for preventing penetration of the salts transported by sea breezes. First we study the effects of factors influencing durability against the concrete which coated and uncoated. Next, we have the result of the concrete properties, chloride contents and carbonated thickness. Finally we conduct the properties of concrete durability up to 36 years age and the method of monitoring test using the full-size members simulating general part of the real structures.

The defects of polyester films used for glass curtain walls, such as discoloration, peeling, and wrinkling, are thought to be caused by degradation. This occurs in a short period (approximately 1/10) of the conventional service lifetime. A comprehensive investigation demonstrated that extremely low ultraviolet (UV) absorber (2,2’,4,4’-tetrahydroxybenzophenone) content in the adhesive coating caused the defects, instead of degradation. To increase bond strength, adhesives are blended using ester compounds with a polar group and small molecular weight, and hence, are easily degraded. Therefore, excess UV absorber addition is essential for extending the lifetime of the film and its function.

For proffer the authorization standard of the act on facilitation reconstruction of deteriorated condominium buildings, studied on evaluation methods and criteria about buildings having the risk of falling cover concrete caused by rebar corrosion. Based on the concept of the binomial test, the number of the deteriorated reinforced concrete elements which highly probable to be the reinforcing bar corrosion higher, is determined by using the data from a survey of the actual buildings. And then, each number of survey points, the criteria for certification was set.

Based on a field survey conducted in Chiba Prefecture after the typhoon Faxai in 2019, the authors evaluated the structural performance of the roofing materials of houses damaged by the typhoon. Since the variance of wind resistance investigated was very large and median of that might be less than the design criteria, the authors conducted an experimental study of the pull-out test using deteriorated wood assuming the roof base material. The test results showed that not only the deterioration but moisture content might be affect for the wind resistance.

Shaking table tests using vibration model are conducted to verify the vibration characteristics of high-damping structural system with multi-story shear walls and dampers. The system can reduce response under earthquakes significantly compared to conventional vibration control system which dampers work in response to inter-story drift. Analysis simulating the tests is also conducted and it reveals that the key index representing response reduction effect of the system is damper deformation amplification ratio.

High damping laminated rubber bearings are highly popular in seismic isolation application. However, due to the nonlinear dependency of the force restoring characteristics on shear strain, energy balance methods cannot be applied to evaluate the response of the isolation layer. Therefore, by replacing the complex restoring force characteristics of high damping rubber bearings with a simple bi-linear model, energy balance methods can be applied. In this paper, several replacement methods are compared in reproducing the accuracy of the response of the isolation layer using time history analysis and considering different earthquake motion phase characteristics and shear strain conditions.

In evaluating the wind response of base-isolated buildings, it is important to consider not only along-wind load but also the across-wind and the torsional wind loads. It is also known that devices using lead or tin with creep potential can be considered unable to resist mean wind force.

In this paper, a simple evaluation method for the wind response of base-isolated buildings is proposed considering the combination of equivalent static wind loads with creep potential.

This paper derives the optimal design conditions by the relational expression of natural period and propose the design method for the tuned mass damper (TMD) using a rotary inertial mass damper called DTMD. It shows the design example for the multi degree of freedom (MDOF) system, and confirms the damping effect of DTMD by the response analysis. In addition, it verifies the proposed theory and confirms the control effect on the actual structure by the vibration tests.

We have illustrated the response changes in the design method for considering the static friction coefficient of elastic sliding bearings in the design of seismic isolated buildings. We also compared the actually observed seismic motion with the response of this design method. According to the results, the design formula and analysis model can reproduce the actual seismic motion, and the response shear force and response displacement change depending on the type of seismic wave when the static friction coefficient is taken into consideration. Therefore, the proposed design method considering the coefficient of static friction is considered appropriate.

In this report, response acceleration of the tower section of an existing wind power generation facility was continuously measured. Vibration models were constructed from these results, and the vibration control effects of single TMD and multiple TMDs were verified for each of the following cases: at standstill, at annual average wind speed, and at rated wind speed. The RMS values of response acceleration and displacement were reduced by about 15% and more than 50%, respectively, at the most frequent annual average wind speed, confirming the vibration reduction effect of the multiple TMDs.

A new vibration control system, Damped braced tube system, is developed for adopting on super high-rise buildings in central Tokyo. This system consists of tube frame using elastic braces and damped slit where a portion of braces are replaced by dampers. Damped slit acting as link beam of coupled shear wall system can dissipate seismic energy very efficiently and contribute to succeeding to meet higher seismic criteria. This paper describes system outline and efficiency through numerical analysis of actual high-rise project expected to be one of the tallest towers in central Tokyo.

Brace is usually installed in aseismic ceiling to keep the aseismic capacity. In the case of high depth ceiling, brace crosses hanging bolt. Experience of several tests show qualitatively that buckling capacity become larger than that of Euler buckling by combining the brace to hanging bolt. Evaluating formula for buckling capacity of brace supported by spring at midpoint is derived and its practical formula is proposed, in which supporting spring ratio ξ and capacity amplifying ratio η are introduced. Buckling capacity of 3 case of lateral loading test results show good agreement with evaluated values by proposed formula.

This study proposes a novel method for generating simulated earthquake motions when considering target response and energy spectra. This method is equivalent to the modal iterative error-correction method, which is effective at solving inverse problems with strong discontinuities. Therefore, this study proposes an improved method for acceleration response and energy spectrum fitting. An outline is provided and details of the method are described. Results of experiments performed to establish method precision are also presented. Variations in the range of energy of seismic motion as calculated by the traditional method are then examined.

Stiffness proportional or Rayleigh damping are well-known typical viscous damping, but since it depends on the frequency, it becomes a problem when the damping coefficient is to be kept constant over a wide period band. As a countermeasure, mode damping is sometimes used, but it is a problem that it lacks practicality in large-scale analysis because the computer load is generally large. In this study, we focus on the capped damping model that gives an upper limit to the damping force of the initial stiffness proportional damping, which is expected to have a certain degree of frequency insensitiveness.

In this study, evaluation methods of subgrade reaction for horizontal resistance analysis of piles using the beam-spring model were studied by simulation analysis of horizontal loading test results of pile. As a result, the analysis for pile head horizontal load obtained results on the safe side when the method of the guideline was used for an evaluation of subgrade reaction. On the other hand, the analysis using an evaluation method of coefficient of subgrade reaction proposed by the authors and an evaluation method of plastic subgrade reaction proposed by Kishida-Nakai produced results that generally corresponded to the measured values.

Grid-purlin system composed of RHS members are known to be effective to prevent buckling of the welded beams. In this paper, the bracing rigidity of triangulation isogrid purlin is evaluated and lattice cylindrical shell composed of arcuate beams and welded grid purlins are studied. The linear, elastic, and elasto-plastic buckling strength of the roof are analyzed using FEM analyses. Their results are compared with the shell theory with continuum analogy and easy design approaches are investigated.

The authors suggest a novel detection method for ceiling damage using image differencing and Grad-CAM. The proposed method requires the latest image and the past image of the facility to compare. It adjusts the difference due to camera position, sunlight condition, etc. The authors show validity of this method showing four pairs of input images. The proposed method can appropriately detect damaged areas with better accuracy for facility inspection by narrowing the areas of inspection using image differencing and Grad-CAM procedures.

This is a structural design proposal of cylindrical shells with interconnected CLTs. To construct the shells with discrete panels, the joints must have axial, in-plane/out-of-plane shear and out-of-plane bending stiffness. For ease of construction, easy-to-handle connectors should be used for joints. In a previous report, the authors proposed an out-of-plane bending joint by using LSBs. In this paper, loading tests of the joints are conducted to confirm the out-of-plane bending properties. In addition, a case study in which CLT shells composed of joints considering stiffness in each direction, including the joints, is adopted to an actual building is presented.

The purpose of this study is to create and verify the performance of large-span parallel chord truss as a design case for medium- to large-sized timber structures. In this paper, the authors carried out the bending tests on full-size truss and validated them with elastic analysis models. The experimental results showed that the yielding of the steel used in the joints plasticized the trusses. In addition, the design criteria were satisfied by applying the uniformly distributed load to an analytical model simulating the truss.

Bending test of reinforced concrete beams using materials imported from Southeast Asia were tested to evaluate the non-contact lap splice length of longitudinal bars encased in grouted corrugated ducts. The test results showed that strengths and deformation capacities of the specimens with a lap splice length 20 times the bar diameter were almost the same as without lap splices. Then, a seismic test of a precast column with a lap splice length 30 times the bar diameter was carried out under varying axial loading. Test results revealed that the strength exceeded the calculated strength and the attained ductility was adequate.

The seismic performance of reinforced concrete (RC) columns retrofitted using the steel plate sandwich method bonded with prestressed PC bars was compared in both in-plane and out-of-plane directions. Therefore, in-plane and out-of-plane bending strength, initial horizontal rigidity, and cumulative energy absorption improved.

In order to prevent the collapse of existing structures not having sufficient seismic resistant capacity, some structural device is required to be appropriately provided. This paper is focused on the development of structural measures to prevent the catastrophic failure of the existing structures under severe earthquakes by installing stacked cubic-hollow steel blocks beside the columns, which will share the loads instead when the columns have lost the load bearing capacities. The effectiveness of the proposed measures was validated experimentally by laboratory tests conducted under various conditions.

In this study, the repairability of RC members is expressed by the rate of increase in repair time with the increase in deformation, and the performance of suppressing the deformation is expressed by the stiffness. Using the repairability and stiffness, “Time Stiffness” which is an index expressing the damage-resistant performance of RC members was defined. This study evaluates the damage-resistant performance of RC columns with wing walls using this index, and discusses its effectiveness as an index to express the performance of suppressing repair time of RC members.

Grid-purlin system composed of RHS members are known to be effective to prevent buckling of the welded beams. In this paper, the joint strength of triangulation isogrid purlin is verified by the 2/3 scale experiment and the I-section beam restrained with isogrid purlin are studied. The ductility of the beams is analyzed using detailed FEM analyses. Their results are compared with the LSD’s standard.

The damage of a steel gymnasium building structure due to strong flood waters was studied through the on-site investigation. The main characteristic points from the damage investigation were shown below.

1) The indoor water flow was varied by the resistance force of the indoor walls.

2) The out-of-plane deformation of bracings due to strong flood flow influences on the in-plain framing responses.

3) The external force to the building due to the flood flow was roughly estimated by consideration based on the careful observation of the damages and several calculations.

In a steel structure building, it is easy to theoretically elucidate the behavior of each member, but it is difficult to evaluate the stiffness and strength at joints. Above all, in the joint where a gusset plate is attached diagonally to the frame and the dampers are connected, beams, columns, and gusset plates influence each other and show complicated behavior. In this study, a bare steel beam with gusset plate is reproduced with a simple model consisting of a rigid zone and a beam element. Furthermore, the rigid zone length and the plastic hinge formation position are shown.

In previous researches, composite structure system made of rammed earth and steel member has been proposed, and mechanical properties and deformation behavior were investigated. This paper suggests an improved composite structural system made of rammed earth and light wight steel member. From the loading tests and a finite element analysis as parameter with states of open/close of wall and thickness of steel, the effective resistant mechanism with adjacent composite structure blocks is appeared, and the combined effect for strength and rigidity is obtained. From analytical results, the relationship between the stress state and the thickness of steel members is investigated.

This is a study by a shaking table experiment of an expansion joint that can follow the movement of two seismic isolated buildings. The response wave of the building is used for the input waveform. The movements of the two buildings were reproduced by using two shaking tables. We investigated the combination of building natural periods in which the movement between buildings is the most intense. We used a wheelchair to check the behavior of the person who was on the expansion joint. We compared the moved distance and acceleration of the wheelchair to see if the risk increased.

The equation to calculate the diameter across all length of bamboo starting from point of 80 mm diameter is incompatible to use in madake bamboo as the type has longer parts with constant diameter. We confirmed that the diameter of bamboo can be calculated using quadratic equation for madake bamboo and linear equation for Moso bamboo, when the diameter at 1000mm from the ground is used as the parameter.

Both bamboos wall thickness could be calculated using linear equation. Through these studies, geometric nonlinear analysis where the results correspond sufficiently with the result of full-scale flexural test is feasible.

In utilizing underground spaces as shelters, vulnerability to water disasters becomes a problem. Use of air pocket, which is closed air-tight space surrounded by walls, could be a solution to reserve area not flooded under the ground. In this study, a fluid analysis method by the 2D MPS method that considers the air pressure in the air pocket is proposed.

In order to obtain knowledge regarding damage mechanisms of building located above surface of the 2016 Kumamoto earthquake fault, the residual deformations of the building were investigated with 3D point cloud data obtained by a laser scanner. The 3D point cloud data contain noise due to measurement error and diffuse reflection. Residual deformations were grasped accurately with method reducing the influence of measurement error by using RANSAC algorism which is one of robust estimations. The validity of the obtained results is also confirmed by comparing other research and evaluating the error.

The performance evaluation method for wooden fire preventive construction with combustible insulation in the Ministerial approval procedure has been significantly rationalized, as the rating for fire preventive performance have been clarified according to the insulation material property at high temperature. The following technical knowledge made this rationalization possible. Under the condition that the insulation material is protected by interior and exterior fire resistive materials, combustible insulation does not burn intensely, but melts and thermally decomposes from the heated side. Therefore, the fire preventive performance of the exterior wall does not decrease even if combustible insulation is used.

In recent years, it has become known that children with developmental disabilities have hearing-related difficulties in the learning environment. In this study, we investigated the influence of ambient sound as background noise on the performance of four different cognitive tasks by subjects with developmental disability characteristics, and whether this was mitigated by the sound absorption of the room. The results showed that subjects with developmental disability characteristics tended to score relatively higher on some cognitive tasks under conditions where sound-absorbing material was installed. While further investigation is needed, the results suggest a positive effect of sound absorption.

As a study on vibration, we have examined the correspondence with human vibration sensation considering the effect of the vibration duration time. However, these studies targeted continuous vibration as one event. In this report, we made a vibration sensation evaluation experiment for a few minutes targeting road traffic vibration, and then we examined evaluation scale for a few minutes. As a result, 「Lv_a,vw(_{All waveforms})+k’ × log₁₀N(_630ms)」(k’=3〜5 ) considering the number of times to perceive vibration was considered as the most responsive evaluation scale for road traffic vibration including the discrete vibration.

It is known that the thermal conductivity of insulation foams increases with time due to the emission of the blowing agents from foams and the transfer of the air into them. In this paper, the aging of thermal conductivity in phenolic foam is discussed with measured data and numerical analysis. Measurement of specimens with different thicknesses and surface material conditions are conducted and the aging characteristics are examined. Using the estimation equations of thermal conductivity change, the effective diffusion coefficient and mass transfer coefficient of the blowing agents is obtained by comparing the simulation results and the measured value.

The potential of using Phase Change Material (PCM) in wooden house has been investigated. Since the cost of the PCM is high, searching for a laying position with high heat absorption and dissipation efficiency has been shown as a problem to solve. At the same time, the internal screen also causes changes in the room surface temperature, which in turn affects the heat absorption effect of PCM. In this study, we focused on how the internal screen affects the thermal storage effect of PCM and discuss the means to improve the thermal storage effect.

In order to increase thermal insulation performance of wooden detached house in a temperate region considering various plans and lower cost, new insulation techniques utilizing internal layers including non-residential spaces, partitions and ceilings without increasing the thickness of insulation in exterior wall were proposed. The six types of two-story house models using internal insulation layers with almost the same floor area but different plans were proposed and were clarified each air conditioning load by numerical simulation. It was confirmed that the thermal insulating effect could be enhanced by insulating the internal layers.

The objective of this work is to compare the apparent thermal characteristics of ten different types of bi-layered materials using the hot disc technique. In this paper, bi-layered material refers to the components of a floor that consist of structural board and finishing materials; both are considered mainly wood-based materials. The result showed the influence of the thermal conductivity of the finishing material was dominant, but in some samples the presence of the air layer on the back side of the finishing material caused a decrease in thermal conductivity of the whole bi-layered material.

This research is to develop an improved technology in a wastewater treatment facility containing fermented buttermilk under operate of a dairy product factory. Wastewater with high concentrations of buttermilk is difficult to treat. Through a new Enzyme Biofilm Method(EBM), we made improvements and demonstrated appropriate wastewater treatment under operation. After two tests, with the improvement of the final stage, despite accepting all buttermilk waste, the improved wastewater treatment has kept decreasing to an acceptable level over the course of a year. This research demonstrates the new EBM’s effectiveness under operate of the wastewater treatment facility containing fermented buttermilk.

In recent years, a part of concerning human body cooling R&D work has focused on fine mist spraying using water vaporization heat. It is much more energy-saving to cool a human body with fine mist than to form an cool spot with an air conditioner. This research aims at clarifying the shortening effect of the “restoring time” from after-exercise sensation to original sensation by installing fine mist area with the cool spot in the radiation cooling/heating office. In this study, we investigated whether repeated exposure to air currents after fine mist exposure would shorten restoring time.

With the promotion of zero energy in buildings,the use of TABS (Thermo Active Building System), a form of radiant air-conditioning systems, is increasing. A survey on the actual conditions of operation in winter was conducted for the TABS adopted in the S Company’s Hokuriku Branch Office. Data on temperature and flow rate of hot water, as well as power consumption of heat pumps and pumps were obtained every one minute. The purpose of this study is to clarify the application effect to buildings by analyzing the energy consumption efficiency of TABS and floor blow air conditioning system.

This study demonstrated the operational performance of a ground source heat pump (GSHP) system in a commercial facility located in a warm region. Whereas the amount of heat generated by the GSHP for cooling was more than 5 times larger than that for heating in the first 2 years, suggesting increase in the ground temperature, the imbalance between cooling and heating was solved after the 4th year by operational improvement. Long-term simulations showed that the operational improvement was effective to mitigate the rise in the ground temperature over the long term, and enabled the GSHP to operate with high efficiency.

In energy saving operation of buildings, it is important to understand the energy consumption characteristics of university campuses in order to formulate specific energy saving plans. Due to COVID-19 expansion, it is assumed that infection prevention measures such as behavior change of students and ventilation are affecting the energy consumption characteristics. It is necessary to understand the energy consumption characteristics that have changed from the conventional ones. In this study, we analyzed energy consumption data on Meiji university campuses for the three years from 2019 to 2021. we clarify the energy consumption characteristics that have changed due to COVID-19 expansion.