Architectural Institute Of Japan Research Articles

Evaluation of prism and diagonal tension strength of masonry form-block walls reinforced with steel fibers

In this paper, the prism and diagonal tension strength of the form-block reinforced with steel fiber developed for improvement of tensile stiffness and crack control performance are evaluated through a series of test. The key parameters of the tests are the steel fiber types that were used for reinforcing block, the strength of concrete and grout mortar as fillers, and the strength of joint mortar. Also, by comparing the design equations in Architectural Institute of Japan (AIJ) Code for block masonry, the performance of the proposed form-block was evaluated.As a result, when the steel fiber is incorporated into the block, the prism strength increases, and in particular, the long-fiber-reinforced block shows the highest strength. However, the diagonal tension strength of the block wall did not show any significant change even though the steel fiber was incorporated, but the stiffness was improved. In particular, the use of long-fiber-reinforced blocks improves initial tensile stiffness compared with short-fiber-reinforced blocks.

Development of a Shear Strength Equation for Beam\u2013Column Connections in Reinforced Concrete and Steel Composite Systems

In this study, we propose a new equation that evaluates the shear strength of beam–column connections in reinforced concrete and steel beam (RCS) composite materials. This equation encompasses the effect of shear keys, extended face bearing plates (E-FBP), and transverse beams on connection shear strength, as well as the contribution of cover plates. Mobilization coefficients for beam–column connections in the RCS composite system are suggested. The proposed model, validated by statistical analysis, provided the strongest correlation with test results for connections containing both E-FBP and transverse beams. Additionally, our results indicated that Architectural Institute of Japan (AIJ) and Modified AIJ (M-AIJ) equations should be used carefully to evaluate the shear strength for connections that do not have E-FBP or transverse beams.

Fire Damage Assessment of Reinforced Concrete Structures Using Fuzzy Theory

Once a reinforced concrete (RC) structure is damaged by fire, the fire damage assessment should proceed to take appropriate post-fire actions, including the decision-making of whether it can be repaired for reuse or not. Since the assessment results of current fire damage diagnosis methods, however, highly depend on the subjective judgment of inspectors, it is hard to ensure their objectiveness and reliability. This study, therefore, aims to develop a new fire damage diagnosis system (FDDS) based on fuzzy theory that can provide objective and comprehensive evaluation results by considering all of the damage conditions observed from the inspection on RC structural members exposed to fire. In addition, the FDDS was applied to an actual fire-damaged case reported by the Architectural Institute of Japan (AIJ, 2009), and it appears that the proposed method provides a reasonable estimation on the fire damage grade of the fire-damaged RC members.

기상자료를 이용한 우리나라 한중콘크리트 적용기간과 초기동해 위험일 산정

본 연구는 기상자료를 토대로 우리나라 각 지역별 한중 콘크리트 적용기간을 KCI 및 AIJ 규정에 의한 방법으로 각각 산정하고 초기동해 위험일을 각 지역 및 온도 단계별로 제안하고자 하였다. 한중 콘크리트 적용기간의 경우 최근 5년간의 기상자료를 토대로 조사한 결과와 종전의 연구결과를 비교하였다. 연구결과에 따르면 국내 91개 지역의 한중 콘크리트 적용기간은 평균 98일로 조사되었고, 고위도 지역일수록, 산악 및 내륙지역일수록 적용기간은 증가되는 것으로 나타났으며, 종전 연구 대비 본 연구의 적용기간이 1~2일 정도 감소되는 것으로 나타났다. 지구온난화, 도시화 등의 영향으로 판단된다. 초기동해 위험일의 경우 <TEX>$-5^{\circ}C$</TEX>, <TEX>$-2^{\circ}C$</TEX> 및 <TEX>$0^{\circ}C$</TEX> 단계별로 시작일 및 종료일을 제시하였으며, 이를 토대로 <TEX>$0^{\circ}C$</TEX> 이하 출현일 수, 출현일 및 평균 추위도를 제시하였다. 본 연구 범위에서 제시된 초기동해 위험일은 KCI에 의한 한중콘크리트 적용기간보다 길게 나타난 지역이 다수 존재하여 한중콘크리트 적용기간 이외에도 초기동해 위험이 있음을 확인할 수 있었다. In this paper, the periods of cold weather concrete and early frost damage depending on each region in South Korea were studied using the climate data from Korea meteorological administration. The specifications of Korea Concrete Institute(KCI) and Architectural Institute of Japan(AIJ) were applied to provide the periods of cold weather concrete. The periods of early frost damage risk(EFD) were calculated by Hasegawa's suggestion depending on 91 cities in Korea. Climate data for 5 years (2008~2012) were used to obtain both of the periods. Existing data from 1971 to 2000 were also used to compare differences in the periods between past and present study. The periods of cold weather concrete by KCI were calculated about 98 days on average. As the latitude goes up and close to mountain areas, the periods tend to be increased. The periods by present study was shown to be reduced compared to that of previous study by 1~2days. The period of EFD was provided with the level of daily lowest temperature from <TEX>$-5^{\circ}C$</TEX>, <TEX>$-2^{\circ}C$</TEX> and <TEX>$0^{\circ}C$</TEX>. The beginning day of the period of EFD was earlier than the period of cold weather concrete and the finishing day of the period of EFD was later than the period of cold weather concrete.

音環境に着目した保育施設の実態調査

A conducive acoustical environment for children is considered essential to support healthy growth. However, the significance of acoustical quality in nursery facilities has not been fully recognized in building design. Further, the management and types of nursery schools are now diversifying and various acoustic disturbances such as excessive noise in the environment or reverberation are often noticed. At present, the architectural Institute of Japan (AIJ) indicates the guidelines for acoustical properties of schoolrooms for elementary schools, as well as junior and senior high schools. AIJ is also working to extend the guideline for schoolrooms to nursery facilities and preschools. Against this background, the study conducted a field survey across twelve nursery facilities to assess the status of acoustical environment. The survey observed the division of spaces for each age, the dimensions of and finish on surfaces in rooms, and children's activities conducted within them. Additional information was collected on the background and characteristics of each facility, the users' evaluation of facilities, and evaluation of the acoustical environment in nursery rooms. Noise levels and reverberation time were measured in four facilities, and a management system to maintain a comfortable sound environment was observed in one facility. The survey on the division of spaces for each age group indicated that in most facilities, the nursery rooms were designed with poor acoustical separation. A typical case of successive nursery spaces was observed in a rented room in a part of the building. Here, the successive spaces were divided by low shelfs or fences, and groups of different ages engaging in different activities shared the sound environment. Additionally, some nurseries were characterized by mixed-age grouping activities and spaces were set not by ages but by activities. Movable partitions and sliding doors were installed to ensure flexible use of spaces according to the activities. Connectivity between spaces was found to facilitate cooperation, but was detrimental to the sound environment. As observed in the survey, such “mono-spaces”—connected rooms without sufficient sound insulation—may cause acoustical problems. As some teachers mentioned during their interviews, there were instances of acoustical disturbance due to voices from other groups. The survey found sound-absorptive materials in use in only a few of the facilities visited. Long reverberation times were measured in nursery rooms without absorptive materials, especially those with a high ceiling and those organized as successive spaces. Another typical problem was noise exposure attributable to the ventilation system and site location such as underneath elevated railway tracks. In nursery facilities, the effects of noise should be considered not only in the context of speech communication, but also in the context of sleep disturbance during naptime. It was observed that a management method to maintain a comfortable sound environment was important. In one nursery facility, nurses pursue the concept of “break away from the noise” and participate in a training session every year. The facility also inculcates practices of gentle vocal communication, and measurements showed lower levels of sound generation during activities. The results of this study indicate considerable differences between the acoustical environments in nursery facilities and school buildings. It is hoped that the findings of this study will be taken into consideration while formulating guidelines for acoustical environments in nursery facilities. It is also necessary to diversify the method to improve acoustical environment through additional absorptive treatment and effective management to maintain a comfortable sound environment.

異形鉄筋のコンクリート内の定着性状に及ぼす拘束の効果に関する実験的研究

Vertical wall reinforcing bars of a boxed wall precast concrete structure in Japan must be anchored straight in the foundation beam. Sometimes, the beam width may not be sufficient to develop anchorage strength in the concrete although the AIJ (Architectural Institute of Japan) Standard for Structural Calculation of Reinforced Concrete Structure requires minimum concrete volume for the development of deformed bars. A series of pull-out tests were carried out to investigate structural performance of anchored bars using various prototype specimens. The purpose of the test series was to study the effect of various parameters and to clarify the failure mechanism. A new series of tests were carried out using high strength deformed bars and varying the foundation beam widths. The anchored bars were pulled out from the base beam exhibiting the relationship between maximum bond stresses and flexural stresses with in the beam. It can be concluded as follows: (1) D19 (diameter 19 mm) deformed bars of Grade SD345 and SD685 (nominal yield stress of 345 and 685 MPa) can be anchored with a development length of 40d (d: bar diameter) for the precast reinforced concrete box-wall construction. When deformed bars are anchored using sheath pipes after construction of the beam, the sufficient development strength was achieved. (2) D19 deformed bars of Grade SD980 were pulled out of the beams of 180, 220, 330, and 440mm widths. (3) Bond failure of a deformed bar developed from the beam top and progresses to deeper region with load. (4) Flexural compressive stresses in the foundation beam increased bond resistance of the deformed bars. (5) Flexural tensile stress or strain of concrete in the foundation beam had less influence on the bond resistance along a deformed bar. (6) The beam width had not much effect on the development strength of a deformed bar within the foundation beam. (7) The development strength of deformed bars was proportional to the flexural compressive stresses in the foundation beam. (8) The development strength increased at a higher rate for beam width less than 180mm, but the increase rate became smaller for the beam width more for 220mm to 440mm.

家庭用エアコンを対象としたCOP測定実験によるカタログAPFの精度検証

INTRODUCTION As the Coefficient of Performance (COP) of heat pump devices varies significantly according to the heating and cooling load and ambient temperature, when selecting a suitable device, it is very important to consider the thermal performance of the house and the local weather conditions. It is common to select a home-use air conditioners according to the room floorage in Japan. The heating and cooling load value per unit floorage from 1964 has not been revised, and is still used in the case of the present air-conditioner selection (maximum heating load per floorage: 275 W/m2). However, this is not the best method for highly insulated houses and leads to problems for energy conservation. In this study, we developed a calorie meter to carry out temperature adjustment, and used it in analysis of the relationships among COP, heating and cooling load and outside air temperature. COP Matrix is constructed by a database of the measurement results. Furthermore, heat load calculation was performed using the insulation efficiency and the local condition of detached housing as analysis variables. As a result of the heat load calculation, Annual Performance Factor (APF) in actual environmental conditions is computed through correlation with the created COP Matrix. The APF calculated from experiment results is compared with the catalogue APF in order to clarify the characteristics of home-use air-conditioners considering the local conditions and heat load conditions. RESEARCH METHODS The indoor chamber of the calorie meter is 3 m wide, 3 m deep, and 2.7 m high. The outdoor chamber is 2 m wide, 2 m deep, and 2 m high. One temperature and humidity sensor and one thermistor anemometer are installed in the inlet of the inside air conditioner unit. Two temperature-and-humidity sensors are installed in the outlet of the inside air conditioner unit. One temperature-and-humidity sensors are installed in the inlet of the outside air conditioner unit, the temperature at this point is the outside temperature. Furthermore, in order to examine experimental accuracy, two thermocouples are separately installed in the inlet and three thermocouples are separately installed in the outlet of the inside air conditioner unit. A COP matrix is created from the relationship of COP, heating and cooling load and outside air temperature. In order to consider the change of APF calculated from experiment results, analysis was performed by changing the insulation efficiency according to the Standard Model issued by the Architectural Institute of Japan (AIJ). We used the meteorological data of the AIJ extended AMeDAS meteorological data. Analysis was performed by heat load simulation software TRNSYS. COP was calculated by collation with the computed COP matrix. RESULTS The COP of cooling is lower when output is relatively low. The COP of heating is higher when the outdoor air temperature is relatively high. And there is a tendency for COP to rise as the flow rate of the inside unit increases. COP matrix in automatic flow rate is similar to COP matrix in relatively small flow rate. Although the APF of an air conditioner in the catalogue is 5.6, which computed from COP matrix in case1-1 (Tokyo) is 2.9, which is about 0.5 times rather than catalogue value. The year cumulative power consumption in the catalogue is about 2,000 kWh, which computed from COP by the COP matrix in case1-1 (Tokyo) is about 3,200kWh, which is about 1.6 times rather than catalogue value. The APF of heating and cooling become lower when insulation efficiency is relatively high. Because the heating load and cooling load is reduced, the frequency of the ON-OFF operation which COP is relatively low is increased.

通しダイアフラム形式の柱梁溶接接合部を設けた鋼梁の耐火性能

Verification on both load-bearing and plastic deformation capacity for a steel beam-column welded connection at elevated temperature is of importance to secure fire safety of steel building structures. At the fire resistant design, it is required that the beam-column welded connection does not fracture before the adjacent heated steel beam exhibits stable plastic collapse mechanism. The AIJ design recommendation (Architectural Institute of Japan, 2017) cannot, however, offer a fire resistant verification method for the beam-column welded connection, because the fire resistance has not been verified experimentally. Main purpose of this study is to clarify both load-bearing and deformation capacity for steel beams including the beam-column welded connections at high temperature, by conducting their experiments under a condition on constant temperature and gradually increasing load. The beam-column welded connection with through diagrams is arranged in the center of beam specimen. The boundary condition is simple support and a shear force is applied through the medium of the column above the beam-column welded connection. In the welded connection, scallop working for a web plate in the wide flange section is not used. This kind non-scallop working is widely used for the actual beam-column welded connections to avoid brittle fracture at the structural design in Japan. The base metal and weld material are JIS SN490B and JIS YGW11, respectively. Stiffener plates to avoid local buckling of the flange plate in the beam are arranged near the beam-column welded connection, because the large tensile force is acted to the welded connection. The number of specimens is five and an experimental parameter is specimen temperature, which is given by ambient temperature, 600, 700, 800 and 900 °C. The specimen temperature was gradually risen by an electric furnace, and the shear force was applied after the temperature reached to the test temperature and kept constant it. Bending moment and rotation angle of the specimen are estimated respectively, and the shear force loading continued until the rotation angle exceeded 0.2. From minute investigations on the experimental results, the following knowledge was obtained. All specimens exhibited the beam bending collapse mode and the welded connections did not fracture. They possessed the larger bending strength than the full plastic moment at each temperature. The shear force applied at the high temperature experiments approximately kept constant with the specimen plastic deflection increase. From specimen observation after those experiments, the weld metal itself in the beam-column connection besides the beam largely deformed, however, ductile cracks in the weld metal and heat affected zone were not observed. It is expected that the beam-column welded connection with the high seismic performance by the non-scallop working also possesses the high load-bearing and deformation capacity at the fire. Furthermore, in-plane numerical analyses using a beam element were conducted, and it was clarified that both numerical and experimental specimen behaviors approximately agreed.

RC造袖壁付柱の曲げ挙動に及ぼす開口位置の影響に関する実験的研究

Practical use of secondary walls such as sidewalls is common because the contributions of secondary walls for stiffness or strength have been recognized. In 2016, “AIJ Standard for Lateral Load-carrying Capacity Calculation of Reinforced Concrete Structures” was published as a draft by Architectural Institute of Japan. In this standard new equations for columns with side walls were proposed. From this viewpoint, the authors have conducted static loading tests of flexurally controlled RC column specimens with single opening in the sidewall, to investigate the effects of openings on strength and deformation capacity of RC columns with a side walls. In this paper, the limitations on location of openings inside sidewalls to avoid their effects on flexural strength and deformation capacity are examined using design equations for flexural strength based on full plastic moment of the column and sidewall. The test results indicate that the proposed limitation line on location of openings to avoid their effects for flexure could be effective for practical design.

宮下欽撮影とされる日本建築学会蔵『震災写真 愛知県之部』『震災写真 岐阜県之部』と各機関に所蔵される『愛岐震災写真』『震災写真』の成立背景と『愛岐両県震災写真説明書』『明治廿四年十月廿八日震災写真説明書』との関係

This article examined "AICHIKEN NO BU" "GIHUKEN NO BU" "AIGI SINSAI SYASIN" "SINSAI SYASIN" photographed by Kin MIYASITA recorded the Nobi earthquake and "AIGI SETUMEISYO" "MEIJI 24 NEN 10 GATU 28 NITI SINSAI SYASIN SETUMEISYO", following points become clear. 1) After the Nobi earthquake, Kin MIYASITA took pictures of the stricken area by the requests of the Aichi Police and the railroad agency. In the collection of photographs settled these, there are "AICHIKEN NO BU" "GIHUKEN NO BU" possessed at Architectural Institute of Japan, "SINSAI SYASIN" at Gifu region meteorological observatory, "SINSAI SYASIN" at Nagoya University, "AIGI SINSAI SYASIN" at Aichi Prefectural library. 2) "AIGI SINSAI SYASIN" was made to explain the photograph of the photo album gathered up particularly, and this may be able to reach "AICHIKEN NO BU" "GIHUKEN NO BU" are equal very well. In other words, it may be said that ２ books are the definitive edition of the Nobi earthquake stricken area photographed by Kin Miyashita. 3) Only the number was written on the photograph mount of "AIGI SINSAI SYASIN" of the Aichi Prefectural library with a writing brush. This number applies to the explanation number in "AIGI SETUMEISYO". Therefore it is thought that "AIGI SINSAI SYASIN" of the Aichi Prefectural library was produced after the establishment of "AIGI SETUMEISYO". 4) From the wrong kanji included in the afterword, "AIGI SINSAISYASIN" of Nippon University was proved to be the earliest establishment as the Nobi earthquake photo album of Miyashita. In addition, "AICHIKEN NO BU" "GIHUKEN NO BU" and "AIGI SINSAI SYASIN" of Aichi Prefectural library where the sequence of the photograph obeyed "AIGI SETUMEISYO" were produced latest, it is thought that these were produced after January, 1892 when "AIGI SETUMEISYO" was edited. 5) Miyashita was concerned with editing of "MEIJI 24 NEN SEYUMEISYO" in the beginning of December, 1891, in the next month, he revised ibidem, and he gathered up "AIGI RYOKEN SETUMEISYO". In addition, the photograph album corresponding to "MEIJI 24 NENSETUMEISYO" has been never seen, but contents are equivalent to "MEIJI 24 NEN SYASINTYO" published in 1931.

Damage evaluation of lightly reinforced concrete walls in moment resisting frames under seismic loading

An experiment was conducted on four lightly reinforced concrete (RC) wall specimens to study the effects of axial force, amount of shear reinforcement, and shear span to wall length ratio on their seismic behaviors such as load and displacement capacities, damage progress, and failure modes. The prototype specimens represented lightly RC walls, which suffered severe damage during the 2011 off the Pacific coast of Tohoku Earthquake. Shear type damage was observed for three specimens tested under double curvature. Increasing the amount of horizontal reinforcement and providing 180-degree hook anchorage reduced the development of shear cracking. A quantitative seismic damage evaluation in terms of crack width, crack length, and concrete spalling area was carried out to investigate the correlation between seismic damage and lateral drift. The damage level of walls was assessed using the 2004 Architectural Institute of Japan (AIJ) Guidelines, which takes into account the level of damage such as residual crack width or stress level of concrete and reinforcement. Considering the total amount of damage (crack length and spalling area), the criteria of the guidelines well captured damage level of lightly RC walls. In order to simulate the damage process as well as hysteresis curves of the tested specimens, finite element (FE) analysis was conducted. The analysis simulated the wall capacities with high accuracy and its crack distributions agreed well with the experiment for all specimens. Additional FE analysis with 210 case studies validated the design equations for flexure and shear capacities.

Review of CFD Guidelines for Dispersion Modeling

This is the review of CFD (Computational Fluid Dynamics) guidelines for dispersion modeling in the USA, Japan and Germany. Most parts of this review are based on the short report of the special meeting on CFD Guidelines held at the International Symposium on Computational Wind Engineering (CWE2014), University of Hamburg, June 2014. The objective of this meeting was to introduce and discuss the action program to make worldwide guidelines of CFD gas-dispersion modeling. The following six gas-dispersion guidelines including Verification and Validation (V&amp;V) schemes are introduced by each author; (1) US CFD guidelines; (2) COST/ES1006; (3) German VDI (Verein Deutscher Ingenieure) guidelines; (4) Atomic Energy Society of Japan; (5) Japan Society of Atmospheric Environment; (6) Architectural Institute of Japan. All guidelines were summarized in the same format table shown in the main chapters in order to compare them with each other. In addition to the summary of guidelines, the overview of V&amp;V schemes and many guidelines of CFD modeling in the USA are explained.

Discussion on size effect of footing in ultimate bearing capacity of sandy soil using rigid plastic finite element method

Currently, many formulas are used to calculate the ultimate bearing capacity. However, these formulas have disadvantages when being applied in practice since they can only be applied for calculating simple footing shapes and uniform grounds. Most formulas do not take into account the size effect of the footing on the ultimate bearing capacity, except for the formula by the Architectural Institute of Japan. The advantage of using the finite element method (FEM) is its applicability to non-uniform grounds, for example, multi-layered and improved grounds, and to complicated footing shapes under three-dimensional conditions. FEM greatly improves the accuracy in estimating the ultimate bearing capacity. The objective of this study is to propose a rigid plastic constitutive equation using the non-linear shear strength property against the confining pressure. The constitutive equation was built based on experiments for the non-linear shear strength property against the confining pressure reported by Tatsuoka and other researchers. The results from tests on Toyoura sand and various other kinds of sand indicated that, although the internal friction angle differs among sandy soils, the normalized internal friction angle decreases with an increase in the normalized first stress invariant for various sands despite dispersion in the data. This property always holds irrespective of the reference value of the confining pressure in the normalization of the internal friction angle. The applicability of the proposed rigid plastic equation was proved by comparing it to the ultimate bearing capacity formula by the Architectural Institute of Japan, which is an experimental formula that takes into account the size effect of the footing. The results of rigid plastic finite element method (RPFEM) with the proposed constitutive equation were found to be similar to those obtained with the Architectural Institute of Japan’s formula. It is clear that RPFEM, with the use of the non-linear shear strength against the confining pressure, provides good estimations of the ultimate bearing capacity of the footing by taking account of the size effect of the footing.

日本建築学会「鉄筋コンクリート造建築物の耐久設計施工指針・同解説」の改定について

日本建築学会「鉄筋コンクリート造建築物の耐久設計施工指針・同解説」の改定について

日本建築学会荷重指針の意義と2015年改定の概要

日本建築学会荷重指針の意義と2015年改定の概要

Field Evaluation of the Vertical Bearing Capacity of a Screw Pretensioned Spun High-Strength Concrete Pile

This study has evaluated the vertical bearing capacity by conducting static load tests for noise-free and vibration-free screw pretensioned spun high-strength concrete (PHC) piles installed using two different methods (end-squirting shoe and pre-boring methods). Vertical bearing capacity differences seem to occur due to the displacement of soils near the external circumference of a pile, depending on the installation method. A method by which to evaluate the bearing capacity of screw concrete piles is suggested by considering the equations that already have been used to calculate the bearing capacity of piles. Based on static load tests and analysis, the pile installed using the end-squirting shoe method was assumed to be a bored pile and it was reasonable to use the equation proposed by the Japanese Geotechnical Society. At the same time, the pile installed using the pre-boring method was deemed a low soil displacement pile and so it was reasonable to apply the equations proposed for calculating the bearing capacity of the driven pile suggested by the Architectural Institute of Japan.

Experimental investigation on strength and curling influence of bolted connections in thin-walled carbon steel

Experimental studies regarding the influence of curling on the ultimate strength of cold-formed stainless steel bolted connections have been carried out by Kim et al. Basic data and modified equations for predicting the structural behaviors considering strength reduction due to curling through the finite element analysis method have also been suggested by previous researchers.In this paper, single shear bolted connections fabricated with four bolts and thin-walled carbon steel commonly utilized in light-weight structural members were tested to investigate the fracture mechanism and curling influence on the ultimate strength. Main variables for test specimen are plate thicknesses and end distances parallel to the direction of loading. Curling (out-of-plane deformation in the direction of plate thickness) also occurred in thin-walled carbon steel bolted connections with a large end distance and thinner plate like previous cold-formed stainless steel connections. The curling occurrence reduced suddenly the ultimate strength of single shear carbon steel bolted connections and the influence pattern of curling on strength was affected according to the plate thickness and end distance. Current design specifications for block shear strength with the combination of tensile fracture and shear fracture are summarized and the ultimate strengths of test results are compared to the predicted design strengths. AISI (American Iron and Steel Institute) and EC3 (Eurocode 3) made conservative estimates of ultimate strength for thin-walled carbon steel bolted connections with no curling, whereas AIJ (Architectural Institute of Japan) and SSBA(Stainless Steel Building Association) manuals provided a good prediction for ultimate strength and fracture mode. Modified strength equations were recommended respectively for bolted connections with typical block shear fracture considering shear stress factor and severe curling accompanied by strength reduction.

日本建築学会「コンクリートの品質管理指針・同解説」の改定について

日本建築学会「コンクリートの品質管理指針・同解説」が16年ぶりに改定された。今回の改定は，2000年以降の建築基準法や工業標準化法など関連法令・基準類の改正やJASS 5等の関連技術資料の改定に伴うコンクリートの品質とその管理方法を取り巻く環境の急速な変化が背景にある。コンクリートの種類と品質は，法第37条に基づきJIS A 5308適合品と国土交通大臣認定品に分類された。また，受入検査および構造体コンクリート強度の検査用供試体の併用方法が規定された。その他，乾燥収縮率やヤング係数などが設計図書で要求された場合の生コン工場の選定方法やコンクリートの性能確認方法が規定された。本稿では，この他主要な改定点および内容について解説する。

日本建築学会「既存コンクリートブロック塀の耐震診断指針（案）・同解説」の刊行

日本建築学会「既存コンクリートブロック塀の耐震診断指針（案）・同解説」の刊行

Experiment on the concrete slab for floor vibration evaluation of deteriorated building

Damages from noise and vibration are increasing every year, and most of which are noises between floors in deteriorated building caused by floor impact sound. In this study, the floor vibration of the deteriorated buildings constructed with the concrete slabs of thickness no more than 150 mm was evaluated by the vibration impact sound. This highly reliable study was conducted to assess floor vibration according with the serviceability evaluation standard of Reiher / Meister and Koch and vibration evaluation standard of ISO and AIJ. Designed pressure for the concrete slab sample of floor vibration assessment was 24MPa, and the sample was manufactured pursuant to KS F 2865 and JIS A 1440-2 with size of 3200 mm × 3200 mm × 140 mm. Tests were conducted twice with accelerometers, and Fast Fourier Transform was performed for comparative analysis by the vibration assessment criteria. The peak displacement from Test 1 was in the range of 0.00869 – 0.02540 mm; the value of peak frequency ranged from 18 to 27 Hz, and the average value was 22Hz. The peak acceleration value from Test 2 was in the range of 0.47 – 1.07 % g; the value of peak frequency was 18.5 – 22.57 Hz, and the average was 21Hz. The vibration was apparently recognizable in most cases according to the Reiher/Meister standard. In case of Koch graph for the damage assessment of the structure, the vibration was at the medium level and causes no damage to the building structure. The measured vibration results did not exceed the damage limit or serviceability limit of building according to the vibration assessment criteria of ISO and residential assessment guidelines provided by Architectural Institute of Japan (AIJ).