In this paper the process of utilization of sea sand and salinity regulation was investigated by literature survey. The limit of sodium chloride of sea sand was stipulated in 1957, and then the limit was become loser and finally the limit of total chloride content of concrete was established in 1986. On the way, survey of reinforced concrete structures, accelerated tests and exposure tests of concrete specimen with re-bars, survey on the regulation of foreign countries, survey of sodium chloride content of sea sand, and development of measuring methods of chloride ion in fresh concrete on site had been conducted.

Various factors such as cement type, curing method, age and mineral admixture affect hydration reaction of cementitious materials. In this study, we conducted the literature survey on the influence of these factors on bound water content, compressive strength and pore structure of hardened cement paste. As a result, it is difficult to indicate the relationship between bound water content and compressive strength or total pore volume with the same formula. However, compressive strength of hardened cement paste could indicate the same formula with total pore volume per unit volume and mass regardless of these factors, excluding mineral admixture.

In this study, the reinforcing effect of short vinylon fibers on premixed lightweight cement mortar for plastering was determined by bending experiments. It was also confirmed that the tensile softening properties of the cement mortar can be evaluated.

In recycled cement concrete using high containing dehydrated sludge powder (DSP), by improving the chemical admixture combined and devising the mix proportion of the concrete, the field casting was made possible, and the field application was tried. The application site was the blindfold wall of the in-house training facility. This paper reports the development of this ready mixed concrete using DSP.

This report is based on a questionnaire survey conducted among formwork contractors nationwide in order to clarify the actual state of formwork construction using softwood plywood using conventional formwork construction methods. Here, we reported on the results of a survey regarding the allocation of qualified personnel for formwork construction, the selection of plywood used in formwork construction, the actual state of use of softwood plywood, and structural calculations for formwork using softwood plywood.

Frost heaving damage to retaining walls occurs frequently in cold regions. This paper focuses on small-scale retaining walls and reports on the following three points. 1. Survey results on frost damage and deformation of retaining walls. 2. Points to design and construction simply based on previous research and experiences. 3. Examples of design and construction of repair work and review of results.

Test specimens with cover thickness of 30 mm was fabricated using concrete containing a large amount of blast furnace slag. After proceeding with carbonation, exposure tests were conducted at different relative humidity, and the self-potential and corrosion current density were measured. As a result, the values of self-potential and corrosion current density were equal when the relative humidity was the same, regardless of the difference in cement type. Therefore, the corrosion rate of rebar after carbonation of concrete containing a large amount of blast furnace slag can be evaluated as being the same as that of concrete using ordinary portland cement.

In recent years, elastic mortar and elastic paint have increasingly been applied to the outer surface of housing base to improve design. Elastic paint can also be applied to the inner surface of the housing base to further improve carbonation reduction effect. In this study, we confirmed the effect of the amount of elastic paint applied on the carbonation reduction effect and the effect of elastic paint on the carbonation reduction effect assuming the deterioration of the inner surface of the housing base over time.

This report presents the results of a survey on salt-damaged buildings in Okinawa. The findings showed that concrete used that period was often made of sea sand that had not been de-salted, and that the wind direction caused significant deterioration of the structures due to the effects of airborne salt and moisture content. However, the influence of wind direction also indicated the importance of considering changes in the surrounding site environment, especially for buildings.

This study investigates mesh resolution for the precise computation of flood loads on a square cylinder using computational fluid dynamics simulations. Even with a coarse mesh, the drag force in the longitudinal direction can be evaluated to some extent, in agreement with the previous experimental results. However, a proper evaluation of pressure distribution requires a mesh division of 50 or more subdivisions in the horizontal direction and 80 or more subdivisions in the corner regions relative to the representative width. Finally, flood loads obtained using an octree-based mesh were discussed for the precise computation.

In this paper, we propose a method of estimating a whole buildings response from only two seismic observation records indicated the relationship between input and output in buildings. This method utilizes data obtained from two accelerometers installed in buildings and a frequency transfer function of multi-degree-of-freedom model based on fast Fourier transform (FFT). Proposed method is applied to actual buildings with seismic observations, the validity of the seismic response estimation method is verified.

The rapid damage estimation of building group in Gunkanjima is carried out through the synchronized measurement of vibration sensor network using MEMS acceleration sensors. The anomalous behavior is firstly detected by tracking the observed acceleration time series of each building. Then, the global damage of each building is investigated by singular value decomposition of the whole frame. Finally, the local damage within each building is scrutinized by evaluating the spectral ratio between observation points of the partial frame. This paper deals with the global and local damage assessment to elucidate the causes of anomalous behaviors reported in the previous paper.

High-density microtremor measurements were conducted in super high-rise residential buildings constructed on soft soil to evaluate the rocking soil springs at basements. First, the overturning moments and rocking rotational angles are estimated using records obtained at the top and plural locations at the base of the buildings, respectively. After confirming the relationship between the overturning moments and rocking rotational angles, the rocking soil springs are evaluated. Evaluated values are compared with those from the strong-motion records and from the analytical models to confirm the validity of the rocking soil springs evaluation method.

The purpose of this study is to consider the effect of size and position of openings in the shell on bearing capacity and fracture geometry. By the method proposed in Reference 3),4), various optimum shell morphologies can be created simply by giving the boundary shape that supports the shell. However, they are not necessarily constructible because of their complex shape due to the simultaneous optimization of shape, thickness, and topology. Therefore, in this paper, test specimen with the same shape as the morphogenesis shell was fabricated and loading experiments were attempted. Then, comparison with the results of analysis is shown.

This study shows change in the relative density of the ground calculated from the cone penetration resistance (CPR) of the ground around the pile after rotation penetration of a steel pile with flat plate wings into dry sand ground. As a result of these experiments with the relative density of original soil and wing diameter as parameters, a region occurred where the CPR decreased as the diameter of wings increased; this was particularly pronounced in high relative density soil. The complicated distribution of the CRP after pile penetration was discussed using the advancement ratio.

We conducted a shaking table test to verify the control performance of TMDs for a gable roof using a scaled-down specimen and two TMD models. The test specimen comprises two-gable frames with 5m span and ridge frames bridging between them. The two TMDs were designed by the double-mass dynamic absorbers method. From the test results, it could be confirmed that the TMDs was very effective for reducing seismic responses except maximum displacement under the El Centro wave loading case. The control performance depended on the vibration characteristics of the TMD device.

Understanding vibration characteristics is fundamental and important information for evaluating the seismic safety of traditional wooden buildings and verifying damage in historical earthquakes. In this paper, we conducted ambient vibration measurements on the ground and buildings of World Heritage Site Nijo-jo castle. Then, we investigated changes in the predominant frequency of the ground and the natural frequencies and vibration modes of the buildings. In addition, we analyzed the effect of coupled vibrations on multiple connected buildings based on the overall shaking of the building.

In a design of large and high-rise timber construction, a hybrid structural system which combines a fireproof steel frame with timber seismic members without fireproof coverings, could be a good solution from both economic and aesthetic point of view. In this research, we developed a joint for steel columns and timber beam with C-shaped inserted steel plate and drift pins. We conducted structural tests on the unit drift pinned joint and the C-shaped joint to obtain the load deformation behavior. From comparison of the test results and the theoretical value, the elasto-plastic behavior of this joint was clarified.

In this paper, we first conduct experiments on the prestressed column-beam joints to confirm the differences in historical characteristics and damage properties with and without LSB. Next, the strains acting on the compression edges are compared, and the effect of the LSB reinforcement on the embedment of the column face is confirmed. Finally, static push-over analysis is performed on the column-beam joints to confirm the process of damage in the column-beam joints with and without LSBs.

Main problems with CLT structures are follows; It is necessary to ensure construction accuracy of the joining metal fitting under the bottom of CLT walls to anchor bolts embedded into R/C foundations. The rotational stiffness and bearing capacity of CLT walls are reduced because the compression side of the CLT shear walls sink into CLT floors when CLT walls are installed on top of CLT floors. The energy absorption capacity decreases due to the slip phenomenon during cyclic loadings. In this report, the metal sleeve connecter filled with high strength grout mortar is developed to solve those problems.

Bending-yield joints such as bolts are often used for joints in timber structures, but there is a lack of data on laminated veneer lumber (LVL). In this study, to confirm influences of the adhesive layer direction of LVL on the strength and stiffness of bolted joints, double shear tests were conducted. The results showed the direction of the adhesive layer didn’t affect the yield strength when washers of sufficient size were used. On the other hand, by using the side members in a direction where washerʼs sinking is less likely to occur, a significant improvement in ultimate strength was observed.

To improve the accuracy and reliability in the seismic diagnosis of traditional wooden buildings, blind analyses of static loading tests on a full-scale specimen of kyomachiya were performed. The followings are very important to develop an analysis model used for the seismic diagnosis. When modeling the column, it is very to consider uplift at the bottom and pulling-out from beam at the top simultaneously. It is also important to consider the loading capacity of mud walls accurately. Additionally, the P-Δ effects and pulling-out of the beam from the beam-column joints should be considered.

Passive controlled shear wall for wooden construction with high damping rubber to prevent degradation of seismic performance during repeated severe earthquakes is proposed in this study. In this paper, shear wall tests and shaking table tests of the full scale two-story wooden structure composed of proposed shear walls were described. As the result of tests, it is confirmed that the proposed shear wall is effective to reduce the degradation of seismic performance to repeated earthquakes in comparison with plywood conventional shear wall.

The authors will develop a composite floor using a combination of wood materials. The floor members need to have fire resistance as well as structural performance. The fire resistance requirements of the floor should be satisfied by the thickness of the concrete portion as required by law. The allowable bearing capacity by law is satisfied only by the thickness of the concrete portion. The occupant vibration should be satisfied by taking into account the effect of compositing the wood and RC parts. The authors conducted loading tests, and creep tests etc. on the composite floor to understand its performance.

As the demand for timber structures increases, the number of rigid frame with a high degree of spatial freedom is expected to increase. On the other hand, experimental methods for such structures have not yet been developed, and a solution is desired. This study aims to investigate a measurement method that can respond to the three-dimensional behavior of a two-directional timber rigid joint. We focused on the three-dimensional coordinates of loading points and the measurement of deformation characteristics of shear panels, and confirmed their validity by integrating the deformation components based on a mechanical model.

Earthquake resistant frame using diagonal glulam columns and steel tie rods are suggested as an innovative timber structure system, implemented in a real building project. This structure system contains glulam columns resisting lateral and vertical load, enables buildings to have flexible architectural space within them. To confirm initial stiffness and strength, a loading test for a partial frame of this structure was carried out. In addition, method for creating stress analysis model of this frame for structure design is suggested by FEM analysis tracing the result of the experiment.

In this paper, compression characteristics of glued laminated timber or cross laminated timber(CLT) subjected to triangular compression on the butt end are discussed. A test machine which is able to control bearing length and the stress distribution is designed, and total 126 specimens with parameters were tested. The results showed shear stress accompanied by friction affects the compression strength and plastic deformation capacity. The effect of rectangular notched hole is also discussed.

When performing microtremor measurements on traditional wooden buildings, it can be difficult to install sensors. This study aims to propose a non-contact microtremor measurement method for tradition wooden buildings using a Laser Doppler Velocimeter (LDV). First, we summarized the LDV measurement system and waveform processing method. Next, we examined the non-contact microtremor measurement method to measure one building of Tofukuji Temple as an example. Then, accuracy of LDV measurement results was verified by comparing the LDV measurement results with the accelerometer results. Furthermore, examples of measurements made on other buildings in Tofukuji Temple were also presented.

The purpose of this study was to develop and verify the performance of end joint in the development of a wooden truss specification for spans over 20 m using residential timber. In order to satisfy the performance requirement, the authors devised a double rafter end joint and conducted experiments and analyses. The performance obtained in the experiment was close to the objective performance. The upper and lower rafters were found to bear the load approximately equally. Comparison of the experimental results with the theoretical formulas for the horizontal stiffness of the end joints showed that the results differed.

European yield theory is a method of calculating a joint strength using several characteristic values, and the method for determining these characteristic values must be clear and appropriate. In Japan, a method for determining characteristic values has been defined for small screws, but no such standard exists for self-tapping screws. The purpose of this study is to investigate and gain knowledge on how to determine the effective diameter of self-tapping screws.

Intended for high-rise timber buildings, horizontal loading tests were conducted under applied vertical loads using the ultra-high strength wooden glued panel. Additionally, elastoplastic analysis using deformation modal theory was conducted. Experimental results showed vertical load affects the skeleton curve of the bearing wall, with stiffness enhanced increasing vertical load. This was attributed to the suppression of rotational deformation at the wall base joint. Maximum strength was largely unaffected. Furthermore, comparative validation analytical and experimental results indicated the analysis generally replicated experimental values. In summary, the feasibility of the bearing wall with an independent vertical and horizontal resistance system was demonstrated.

This paper presents the simplified approximate equation for the ultimate moment of reinforced concrete exterior beam-column joint. The proposed equation is constructed of the dominant terms of the theoretical equation. The convergent calculation is omitted, and the neutral axis ratio and the stress of the outside column rebar are given by empirical equations. The proposed approximate equation is applicable not only when both the beam and column rebar yielding but also when the stress of the column rebar is given by the critical reinforcement.

In this study, experimental study on the structural performance of geopolymer concrete RC members using stainless steel bars were conducted. To compare the structural performance of ordinary-steel bars and stainless-steel bars, pull-out tests and flexural beam tests were carried out. In the pull-out test, there was no significant difference in the maximum bond stress and the slip at that time. In the beam tests, all the test specimens fractured with bending failure where the concrete on the compression side collapsed after the tensile reinforcements yielded. There was no clear difference regardless of the type of concrete and steel bar.

The calculation method for the shear strength of columns with wing walls was developed. In this proposed method, the shear strength is calculated by the truss theory. The calculation results by the proposed method corresponded well with the experiment results.

Although post-installed anchors are used for seismic reinforcement and installation of equipment, there is concern that the anchorage performance of anchor bolts anchored to base concrete with a surface layer that has been subjected to frost-damage will deteriorate. In this study, pull-out tests of post-installed anchors anchored to a specimen with a simulated surface layer subjected to frost-damaged concrete were conducted to investigate cone fracture of concrete. The results showed that the tensile strength of the deteriorated specimens was lower than that of the non-damaged specimens.

This paper reports a construction survey of steel roof structures in Tohoku Prefecture. The research is based on a basic database of the cross-sectional performance of beams and non-structural members from the total of 1345 steel roof structures in Tohoku. Also, this paper clarified the bracing effect performed by the non-structural members on lateral buckling strength of main beams using the relationship between the stiffening capacity of large beams and nonstructural members. The modified lateral buckling slenderness ratio considering the stiffening effect of nonstructural members may be in the range of 100 to 180.

Riveted joint is one of the joining methods for steel structures, but the JIS standard for rivets has been abolished at present, and it is impossible to use the conventional SV standard. Therefore, authors developed riveted joint by a new method using SNR400B. This paper reports on the results of material tests conducted using the SNR400B and the inspections and construction flow that were carried out to ensure construction quality when applying revets to actual buildings.

We have developed the non-welded joint method for existing steel pipe members and verified the fundamental performance of the method. The non-welded joint method uses epoxy resin adhesive and grout to transfer the shear force, axial force and bending moment to the retrofitting members. As a result of the tests, it was confirmed that the proposed joint satisfied the design strength calculated by the nominal strength of epoxy resin without any significant damage, and the beam theory can be applied to estimate the load-deformation relationship of existing steel pipe members.

In the top-down construction method, a cast-in-place concrete pile head embedded with steel column is usually arranged reinforcing bars to prevent splitting at the pile head. The reinforcing bar has been designed in accordance with the conservative guideline because of few past studies. This study inspected the effect of arranged reinforcing bars near the bottom of the embedded section for the axial compression strength of the pile head. It evaluated the pile strength for CFT column through experimentation using the pile diameter as a parameter arranging the reinforcing bars near the bottom of the embedded section of the specimen.

In this study, to further improve the performance of the adhesive anchors, pullout tests were conducted on adhesive anchors with different combinations of adhesive and borehole diameter to determine the maximum load along with the fracture type of the adhesive anchors. The load capacity calculated by AIJ’s current design guidelines was compared with the experimental fracture load. The results show that the maximum load of adhesive anchors fixed in large-hole with three types of adhesives are higher than the ones fixed in conventional-size-hole regardless of the fracture mode. AIJ’s current design criteria provide lower limits of fracture loads for them.

In this study, as for concrete beams using CFRP rods as the main reinforcement, a sequential analysis by means of the equivalent stress block was presented, which is simple and has the same accuracy as a non-linear cross-sectional analysis based on the Bernoulli-Euler theory. Furthermore, a post-peak flexural behavior of the beam was analyzed and the ultimate strain of concrete at the ultimate limit point in flexure of a continuous fiber reinforced concrete beam was discussed.

Glass itself is a flat pane and difficult to make H-shape like steel beam. Therefore, glass deformation is large, and it is always required some stiffeners to reduce derived deformation on the pane. The authors take this issue into account and develop the solution using slender tempered glass stiffeners. This paper reports the structural behavior of T-shape glass screen through full-scale experiments. In addition, this research compares the experiments’ results and finite-element analysis results, which applied sealing properties. Through this comparison, this research shows the reliability of the proposed system.

In this study, the effects of 10 types of cement used for lightweight cement mortar on the fire-resistance performance of the exterior wall of lightweight cement mortar were evaluated. As a result of the heating test, ordinary Portland cement showed the highest temperature at the back surface of lightweight cement mortar, and alumina cement showed the lowest temperature. As for non-damage, there was no explosion or falling off, and no significant difference in damage was observed.

“Introduction to Environmental Vibration Design for Ensuring Habitability” provides example performance matrices for road traffic vibration in different period. However, there are few reports on vibration measurements for one week. In this report, vibration measurements were conducted on a detached wooden house for road traffic vibration for approximately eight months to examine vibration levels over a longer period. The results showed that there was a large variation in vibration levels in the subject house depending on the day of the week. In addition, input level ratios were obtained for the target period.

The foundations of buildings are required to embed to the freezing depth by The Building Standards Act in Japan. However, due to the ambiguity of the definition of freezing depth and engineering grounds, operational rules differ from region to region. Therefore in this report, the author investigate the current standards and calculation methods of freezing depth and organize the issues.

In this study, we aimed to clarify the effect on comfortable room temperature when various local low-temperature airflows occur during natural ventilation, and calculated PMV-t_eq from the body equivalent temperature of the thermal manikin experiment. Comparisons were made with the thermal sensation results of subject experiments under these conditions. As a result of the subject experiment, under the 29℃ condition, the PMV-t_eq and the average thermal sensation value were close to each other. However, under conditions of 22℃, the subjects felt colder than expected based on PMV-t_eq, and it seemed necessary to consider local discomfort as well.

To verify the feasibility of low-rise underfloor air distribution system with a wall-mounted air conditioner, we conducted a demonstration experiment of the temperature distribution inside and outside the floor chamber using a full-scale mockup. We conducted experiments with 12 settings, including the air conditioner’s air volume, direction adjustment function, and the position of the air outlet slit. Even when the chamber was set relatively low (i.e., 145 mm inside height), hot air could reach quite far but not to either side of the air conditioner. Changing the position of the slit or installing a counter blower effectively solved that problem.

The cooling operational performance of TABS combined with floor supply displacement air conditioning system adopted in the Tohoku Branch of S company was investigated. The purpose of this research was to evaluate four control methods and clarify their energy consumption efficiency and load leveling effects. By operating with the proposed control method, the peak amount of received power was reduced by approximately 10%, confirming high energy consumption efficiency. Additionally, a thermal environment was created in the office as planned, with small temperature differences.

To investigate the applicability of the internal insulation retrofit to soundproof work, actual measurements (winter) and numerical analysis (summer and winter) were conducted in an actual house where soundproof work and internal insulation retrofit were performed at the same time. As a result, those retrofits were not very effective in reducing the heat shock risk in winter, but improved comfort in the living and surrounding rooms and reduced air conditioning loads. It can be concluded that there is potential for the application of internal insulation retrofit to soundproof work of living rooms.

A large proportion of energy consumption in Japan is attributable to houses, and that of household appliances is not negligible. However, as the Energy Conservation Act in Japan does not cover household appliances such as electric heating devices, sufficient measures for energy saving of household appliances are not provided. In this study, by analyzing HEMS (home energy management system) data, we have surveyed the power consumption of electric heating devices, bathroom heaters, and other appliances in recently built houses in Tokyo and Kanagawa prefectures. In addition, we have estimated the effect of equipment replacement into high-efficiency ones.