Internal Strengthening Research Articles

PERKEMBANGAN HUKUM PERDATA DI INDONESIA TINJAUAN HISTORIS DAN KONTEKSTUAL

<p><strong>Abstract: </strong>Changes and developments in civil law occur because law is dynamic, and is also influenced by Human civilization is increasingly shifting day by day along with technological developments and global warming. Civil law is essentially closely related to internal strengthening control function that replaces the external supervision function. Modern civil development law because its basis is always related to the relationship between the government regime and community, thereby strengthening the participatory role of society in one aspect. One Forms of civil law modernization that are developing include, among others; Contract law, consumer protection law, and employment law, as a form of strengthening internal functions related to external control function.</p><p><strong>Keywords: </strong>Civil law, Developments, Change</p>

Enhancing the punching performance of two-way RC flat slabs using different configurations of embedded aluminum sections: Experimental program and numerical analysis

Punching occurs in flat slabs around the column as a result of increased column loads, inadequate steel reinforcement, and weak concrete strength. The goal of the current research is to improve the punching resistance of two-way reinforced concrete (RC) flat slabs using internal strengthening with aluminum sections. An experimental program consisting of ten RC flat slabs was prepared and tested to show the effects of three different strengthening configurations (horizontal and vertical, diagonal, or hybrid system consisting of horizontal, vertical, and diagonal sections) on the structural characteristics of RC flat slabs. Also, the effect of the thickness of the strengthening aluminum sections (1.0, 1.5, and 2.0 mm) on the ultimate load, load-mid span deflection responses, stiffness, and absorbed energy of RC flat slabs was investigated. According to the results, the three slabs in the group with the vertical and horizontal aluminum sections had the highest improvements in ultimate loads among all tested slabs of 50.9%, 57.1%, and 68.9% for aluminum thicknesses of 1.0, 1.5, and 2.0 mm, respectively, compared to the control slab. Moreover, a three-dimensional (3D) non-linear finite element model (FEM) was constructed using ABAQUS software. The proposed model was validated using the experimental records. Then, the validated model was used to investigate the effects of the interspacing between the aluminum sections on the ultimate load, load-deflection responses, stiffness, and absorbed energy of two-way RC flat slabs.

Numerical Study on Slender Circular Reinforced Concrete Column Clamped with Steel Sheet

Various methods to enhance the performance of circular reinforced concrete column have been widely investigated. However, most researches used internal strengthening method such as intensifying steel reinforcement. Others utilized carbon fiber reinforced polymer (CFRP), glass fiber and aramid to retrofit either reinforcement or concrete surface. Few studies incorporated steel to cover concrete surface but neglecting clamp pressure between steel and concrete surface. This study proposes a steel sheet strap strengthening method by initial clamping stress on steel sheets as an external confining technique through experimental works and in-depth numerical analysis. The experimental investigation includes nine steel sheet strengthened reinforced concrete specimens of 20 MPa subjected to axial concentric and axial eccentric. Retrofitting devices will be fabricated from BJ37 steel. Steel sheet straps in each specimen will be subjected to varying initial clamp pressure by fastening bolts. Applied load, lateral displacement and vertical and horizontal deformation will be measured by the instrumentation. Experimental works will observe failure mode, force displacement, stress and ductility. Section analysis based on experimental results will define compatibility equations for numerical stage. Strengthening model from experimental stage will also be analyzed in numerical study with inhouse software 3DNLFEA. F-D curve and moment-curvature loading behavior and ductility will be obtained from numerical analysis. It is believed that the proposed strengthening mechanism with its geometrical and stress variations could enhance the section, member and structural ductility of circular reinforced column against vertical and lateral load. Furthermore, the developed analytical model could well predict the behavior of the proposed clamp mechanism for practical applications.

Shear Behavior of Reinforced Concrete Beams with Different Arrangements of Externally Bonded Carbon Fiber-Reinforced Polymer

Carbonfiber-reinforced polymer (CFRP) composites are frequently utilized in the repair and reinforcement of reinforced concrete members because they are more corrosion-resistant, durable, and flexible than commonly used materials like steel plates. Many studies have demonstrated that the use of CFRP as an internal strengthening material has a substantial impact on the shear capacity of RC beams. This research looks into the possibility of using FRP material as an externally bonded reinforcement to increase the shear strength of RC beams. Because shear improvement and mode of failure are based on the right configuration of the CFRP sheets, the experimental work consisted of eight RC beams with various types, orientations, and configurations of CFRP sheets. All beams were examined under two-point bending. The test results show that the CFRP sheet significantly improved the beam’s shear strength and ductility and that it is advantageous to orient the FRP at 45 degrees to the beam’s longitudinal axis.

Impact of Internal CFRP strips on the flexural behavior of heat-damaged reinforced concrete beams

Recent theoretical developments revealed that reinforced concrete (RC) structures are susceptible to deterioration risk upon exposure to high temperatures where the mechanical properties of their constituents are affected and therefore require upgrading their overall performance. However, the overall behavior could be improved by strengthing the RC beams using the well-known carbon fiber-reinforcement polymers (CFRP) materials where its efficiency is highly limited by detachment, and debonding problems appear as a result of the weakness in the bond between the concrete surface and the strengthening material or upon the stress concentration induced by the various anchoring systems. The CFRP sheets have been integrated as internal reinforcement in the maximum bending zone within the thermally damaged beams, a new technology used in this study. The suggested method was the first of its kind and did not need an adhesive to be applied where debonding problem is eliminated. In contrast to conventionally reinforced steel, CFRP composite materials are fully compatible with flexural steel and constrained concrete. A total of 40 RC with (150 × 200) mm2 and an overall length of 1100 mm concrete beams were cast, and the studied parameters were the CFRP length, position, and exposure temperature. The internal strengthening technique has been found to ensure the full utilization of the strengthening material where the externally-strengthened beams fail preceding the CFRP strain reached, and this was confirmed using the linear weighted sum method where the internal strengthening has the highest ranking based on the mechanical characteristics comparisons. Moreover, the internal CFRP reinforcement improves RC beam performance, strength, stiffness, toughness, and serviceability more than exterior CFRP sheets. However, the enhancement percentages are twice as much for internal strengthening as the external one. It has also been found that the reinforcement's location substantially impacted the number and length of flexural cracks and its failure mode. In addition, for every 1% reduction in concrete compressive strength in heat damage, the average ultimate load was reduced by 0.8%. The CFRP profitability indexes decrease as sheet number and temperature increase; the average toughness decrease at 150 °C, 250 °C, and 500 °C is 12%, 21%, and 47%, respectively.

Case study of shear strengthening of RC Corbels by steel plates using fea

The study aimed to explore the possibility of strengthening RC corbels with many strengthening techniques. The research analyzed the RC corbels behavior under a wide range of variables. The theoretical study consisted of twelve models reinforced with GFRP bars with strengthening by steel plate. Finite element analysis with ANSYS APDL was used to verify five specimens. This research deals with a static nonlinear FE simulation to investigate the behavior of RC Corbels reinforced internally and externally. The verification with experimental work demonstrated a satisfactory agreement in the load-displacement relationship, ultimate load and displacement, and failure mode. The parametric study was implemented which included strengthening the four concrete corbels externally and four corbels internally by a steel plate in many configurations while the remaining three were modeled with varied compressive strength (30, 40, and 50) MPa. The external strengthening included the placing of steel plate externally around the corbel in a U-shaped form and partial strengthening by strips and bottom plate. The models with internal strengthening involved placing the steel plate internally instead of stirrups. The results discovered that the strengthening provided enrichments in the stiffness, ductility, and energy absorption by 37 %, 4 %, and 26 %. In addition, in the case of full external strengthening more than internal retrofitting, there is a maximum improvement in the cracking and ultimate load carrying capacity. The external strengthening was better than internal one due to the confinement effect of the concrete. The stress distribution and crack pattern were affected by the strengthening techniques and more cracks appeared in the corbels with external steel plates.

Pull-out test of carbon-fiber composite cable (CFCC) tendon for an internal anchorage

An internal strengthening system involving the embedding of a post-tensioned prestressing tendon in a wedge-shaped anchorage of an existing concrete member was developed previously. The previous study confirmed the adequate load capacity of the prestressing tendon for the internal strengthening technique. The tendons used in the previous investigation were steel-rigid bar and steel-wire cables. These steel tendons are prone to corrosion under severe environmental conditions, such as bridge deck slabs sprayed with deicers. Carbon fiber composite cables (CFCC) are occasionally employed as tendons in prestressed concrete bridges. This study focused on the non-metallic material and examined the load capacity of CFCC tendon in internal strengthening systems to achieve the feasibility of the technique under corrosive environment. The main concern of the novel strengthening system was the anchoring system of the CFCC in the internal wedge. In general, both ends of the CFCC tendon can be gripped with external fasteners and be provided a tensile force using a hydraulic jack. In an internal prestressing system, a CFCC end must be anchored without any external fastener. It is preferable to simply fix the CFCC in a small wedge anchor made of existing concrete. This study focused on developing a CFCC anchoring method in a wedge-shaped hole and examined the tensile load capacity of the CFCC tendon fixed in the anchorage. The end of the CFCC tendon was reversely twisted to improve the pullout resistance by increasing the diameter of the cable. To examine the load-bearing capacity of the developed CFCC tendon, a mock-up reinforced concrete (RC) block with an internal wedge-shaped anchorage was used. A CFCC tendon equipped with a reverse-twisted tip was inserted into a wedge-shaped hole filled with high-strength grout. A pull-out test of the CFCC tendon was conducted to examine its load-bearing capacity. The test results revealed that the CFCC tendon with a reverse-twisted tip embedded in the anchorage exhibited adequate load-bearing capacity. This study confirmed that the post-tensioned prestressing system using the CFCC tendon is appropriate for strengthening RC members having the thickness of at least 200 mm, such as bridge deck slabs.

Реформы Иосифа Вельямина Рутского как фактор укрепления униатской церкви на белорусско-украинских землях в первой половине ХVII в.

Introduction. This article discusses the impact of the reforms of Joseph Velyamin Rutsky, who headed the Kyiv Uniate Metropolis in 1613-1637, on the further development of the Uniate Church in the Belarusian-Ukrainian lands.Materials and methods. The article was prepared on the basis of a critical analysis of the historiography of the history of the Uniate Church and published historical sources, including the works of Joseph Velyamin Rutsky. The principles of objectivity and historicism served as the methodological basis. The author of the article used general scientific (analysis, synthesis, comparison, generalization) and special historical research methods (comparative historical, historical genetic).Results. The main achievements of Metropolitan Rut-sky were the monastic reform and the formation of the congregation of the Holy Trinity, the creation of a network of Uniate schools, raising the educational level of the clergy, and reforming the administrative-territorial structure of the Kyiv Uniate Metropolis. He defended the interests of the Uniates at meetings of the diets, opposed the proselytism of the Latin clergy and the conversion of believers to the Latin rite. On this path, he was accompanied by both successes and failures.Conclusion. The activities of Joseph Velyamin Rutsky contributed to the exit from the crisis state of the Uniate Church, its internal strengthening and the formation of sufficiently strong foundations for its further existence. At the same time, this became a serious challenge for the Orthodox, complicating their position in the Commonwealth.

Bureaucracy Entrepreneurship Strategy Waste Management in East Priangan, Indonesia

The limited quantity of human resources and inadequate service and bureaucracy in waste management services in East Priangan have made waste management in the area very ineffective. The lack of facilities and infrastructure, public awareness, and the absence of rules and strategies in waste management then exacerbate this. This study then aims to see how the entrepreneurial strategy of waste management bureaucracy can be implemented in East Priangan, Indonesia. This research is descriptive qualitative research using SWOT analysis. The data used in this study came from interviews and literature studies regarding studies that still relate to the research discussion. The results of this study then found that waste management in East Priangan uses five strategies, where the Core Strategy and cultural strategy are going well, while the Consequence Strategy, Customer Strategy, and Control Strategy can be said to be not optimal. The strategy for entrepreneurship in the waste management bureaucracy that is effective in East Priangan is an Aggressive Strategy (Growth Oriented Strategy), meaning that the organization is in a steady state by maintaining the previous strategy and seeking necessary improvements to be further optimized through internal strengthening or future innovation.

STRATEGI KOMISI PEMILIHAN UMUM KALIMANTAN TIMUR DALAM MENINGKATKAN ANGKA PARTISIPASI PEMILIH PADA PEMILU SERENTAK TAHUN 2024

Strategy of the General Election Commission (KPU) of East Kalimantan in Increasing Voter Participation Rates in the 2024 Simultaneous Elections, Emi Rohaimi, Postgraduate Masters Program in Public Administration at Mulawarman University, February 2022, Prof. Dr. Hj. Aji Ratna Kusuma, M.Si and Prof. Dr. Hj. Hartutiningsih, M.Si.This study aims to produce a choice of strategies and efforts that can be considered by the East Kalimantan KPU in increasing voter turnout in the 2024 election. The study uses a SWOT analysis model in a qualitative approach.The results of the study show: 1. That there are a number of strategic options for the East Kalimantan KPU, namely (1) SO: regulation, internal-external cooperation, completing infrastructure, optimizing funding sources. (2) WO: optimizing human resources with stakeholders and new partners, strengthening communication and coordination partnerships, controlling critical thinking, and developing creativity. (3) ST: regulation suppresses negative competition, HR suppresses hardline and transactional group thinking; National government and local government funding; complete the facilities and infrastructure; strategies and methods of controlling critical thinking in urban communities. (4) WT: preventing negative competition for election participants, optimizing ethok officers or volunteers as well as driving cadres, developing Regency/City KPU creativity; communication and coordination prevent misunderstandings; critical and intelligent thinking control partnership; 2. Efforts that can be made by the East Kalimantan KPU to increase voter participation rates. (1) Internal strengthening, utilizing and empowering strengths and minimizing weaknesses. Improving the quality of human resources, partnerships with educational and political institutions, as well as suffrage education. (2) Paying attention to national and regional dynamics to deal with external conditions with the assistance of Regency/Municipal KPU for well-targeted socialization. Keywords: Strategy to increase voter participation, General Election.

Strengthening of Structural Flexural Glued Laminated Beams of Ashlar with Cords and Carbon Laminates.

Changes in the condition of existing timber structures can be caused by fatigue or biological attack, among other things. Replacing damaged timber is still very expensive, so it seems more advisable to repair or reinforce damaged elements. Therefore, in order to improve the static performance analysis of timber structures, reinforcement applications in timber elements are necessary. In this experimental study, technical-scale glulam beams measuring 82 × 162 × 3650 mm, which were reinforced with carbon strands and carbon laminates, were tested in flexure. A four-point bending test was used to determine the effectiveness of the reinforcement used in the timber beams. Internal strengthening (namely, glued carbon cords placed into cut grooves in the last and penultimate lamella) and an external surface of near-surface mounted (NSM) carbon laminates glued to the bottom surface of the beam were used to reinforce the laminated ashlar beams. As a result of this study, it was found that the bending-based mechanical properties of ash wood beams reinforced with carbon fibre-reinforced polymer composites were better than those of the reference beams. In this work, the beams were analysed in terms of the reinforcement variables used and the results were compared with those for the beams tested without reinforcement. This work proves the good behaviour of carbon fibre reinforced plastic (CFRP-Carbon fibre reinforced polymer) cords when applied to timber beams and carbon laminates. This study illustrated the different reinforcement mechanisms and showed their structural properties. Compared to the reference samples, it was found that reinforcement with carbon strings or carbon laminates increased the load-bearing capacity, flexural strength and modulus of elasticity, and reduced the amount of displacement of the timber materials, which is an excellent alternative to the use of ashlar and, above all, inferior grade materials due to the current shortage of choice grade. Experimental results showed that, with the use of carbon fibre (carbon cords SikaWrap® FX-50 C-Sika Poland Sp. z o.o., Warsaw), the load bearing capacity increased by 35.58%, or with carbon cords SikaWrap® FX-50 C and carbon laminates S&P C-Laminate type HM 50/1.4 - S&P Poland Sp. z o.o., Malbork, by 45.42%, compared to the unreinforced beams.

The optimal opening ratio of the internal diaphragm of the beam to CFRST column connection

To reduce the obstructive effect of the internal strengthening diaphragm to the pumping concrete during the construction of the concrete-filled rectangular steel tubular column, an optimization suggestion and method for the opening ratio of the internal strengthening diaphragm are proposed. The finite element analysis method was used to study the factors that affect the opening ratio of the internal strengthening diaphragm. It was found that the main factors affecting the opening ratio of the internal strengthening diaphragm are the ratio of the beam width to the column width, the beam layout, and the thickness of the internal strengthening diaphragm. Based on the above parameter analysis, a method to determine the optimal opening ratio of the internal strengthening diaphragm is proposed. In addition, two new forms of internal strengthening diaphragm are proposed, which are the octagonal internal strengthening diaphragm and cross-shaped internal strengthening diaphragm. Under the condition of satisfying the design principle of equal strength and deformation limitation, the octagonal internal strengthening diaphragm can obtain a larger opening ratio and smaller column deformation than the traditional internal strengthening diaphragm. Under the condition of satisfying the deformation restriction, the cross-shaped internal strengthening diaphragm can further increase the opening ratio of the internal strengthening diaphragm.

PERKEMBANGAN SMART CITY TANGERANG SELATAN TAHUN 2016-2021

Uneven development causes the level of urbanization to be higher, which causes urban problems in both physical and non-physical forms. Based on this, the City of South Tangerang is increasing the development of the city into a Smart City. This study examines the stages of development of South Tangerang City into a smart city. This research is a qualitative descriptive study, with data collection techniques using interview techniques, in-depth observation, and documentation studies. Research theory using city management, and smart city. The results of this study are the stages of South Tangerang City towards Smart City in 2016-2021 is a development that can be said to be short, consisting of three stages. The first stage 2016-2017 is the preparation stage in the form of internal strengthening. The second stage 2017-2018 is the planning stage in the form of policy formulation and implementation guidelines for Smart City. And the third stage (2018-2021) which is the stage of implementing the plan in the form of achieving targets and indicators that are continuously monitored and evaluated. Based on the results obtained, it can be concluded that the stages planned by the South Tangerang government in building a smart city can fulfill the smart city vision.

The orientation effect of opening and internal strengthening on shear performance of deep concrete beam using recycled tyre steel fibres

A deep concrete beam is a structural member that transfers heavy loads from the introduced column(s) due to a change of function layout of a particular floor in the building. Due to its high depth, the service utilities are always accommodated by creating a transverse opening rather than at its soffit. However, this practice leads to a reduction of shear resistance and affects the serviceability of the beams. To reinstall this capacity, waste tyre steel fibres were used to assess their effectiveness in improving the shear resistance of the deep concrete beams with openings. Three sets of beams with, without fibres, and with fibre mesh that had openings of 160 × 86, 115 × 120, 86 × 160, and 165 × 170 mm were considered. A total of 16 beams with dimensions 150 × 400 × 1100 mm and a constant shear span-to-depth ratio of 0.8 were cast and tested. The steel fibres used had a diameter of 1.3 mm, a length of 50 mm, a fibre content of 0.5% and a fibre mesh of 110 × 100 mm. The main variables evaluated were the effect of the opening size and its orientation, the effect of stirrups, the random mixing of fibres in the matrix, and the internal strengthening of the fibre mesh in the anticipated strut line of the deep beam. The results showed that an interruption of the strut width affected the shear resistance of the beam. The beam with 160 × 86 mm had a lower capacity of 7.7% compared to 115 × 120 mm with the same opening area. The 160 × 86 mm control beam had a high shear capacity of 2.6% compared to 86 × 160 mm. The inclusion of fibre increased the compressive stiffness of the strut; The beam with fibre and opening size 165 × 170 mm had a shear capacity of 37.8% higher than the beam without fibres. The addition of mesh had a limited increase in shear capacity compared to random fibre mixes; however, the capacity was 21.6% higher than the control mix for a beam with an opening size of 165 × 170mm. Therefore, it is recommended to use recycled waste tyre steel fibres to improve the shear capacity of the deep concrete beam and less application of shear bars.

The Self-compassion during Pandemic Covid-19: Cased in Jember District

Policy of restrictions on activity during pandemic covid-19 has a negative psychological impact. Thus, the need for good self-management so as not to cause stress, anxiety in the face of pandemics. One of the self-management used by improving self-compassion. Self-compassion is an attitude to be able to be open, to be aware of mistakes that occur to yourself, so as to positively interpret negative experiences. Self-compassion can increase the body's immunity, reducing anxiety. The purpose of this study is to describe the self-compassion of Jember people during the pandemic.The study used a descriptive quantitative approach with the subjects of covid-19 affected communities in Jember, numbering 349 respondents. The data collection method uses questionnaires with purposive sampling techniques, adapted from Neff's Self-compassion Scale (2003) containing 26 items with a total reliability of 0.93. The results showed that as many as 60 respondents (17%) people in Jember had moderate Self-compassion, with the highest percentage of Mindfullness aspect as many as 65 respondents (19%). While the lowest percentage in Isolation aspect is 60 (17%). Reviewed by gender, female subjects had a low self-compassion of 39 respondents (15%), compared to 14 male respondents (14%). Based on tribe, Madura has low self-compassion compared to other tribes, 12 respondents (18%). Based on the results of the research, it can be used as a reference for related parties to form community intervention programs based on internal strengthening and spirituality, and the community can understand the importance of mental health through self-compassion.

Fire behavior of novel Thread-anchored One-side bolted connection with internal component

Anchorage of the novel Thread-anchored One-side Bolt (TOB) is provided by the threads inside the bolt hole and the TOB could be installed from one side only, which provides an alternative way to install the connection of the Square Hollow Section (SHS) column. But the TOB might be pulled out from the threaded bolt hole when the SHS column wall is deformed, especially in fire conditions. The strengthening component could be installed inside the SHS column to restrict the deformation of the column wall and increase the depth of the threaded bolt hole. The tensile behavior of the TOB bolted SHS column connection and the influence of the internal strengthening component on the connection at fire scenario were studied and compared with Standard High-strength Bolted (SHB) connections by experimental method. Both steady-state fire test method and transient-state fire test method were used in the test. The TOB bolted SHS column connection had two typical failure modes, which were the yielding of the column wall (mode 1) and the yielding of the T-stub flange accompanied with the bolt failure (mode2), depending on the thickness of column wall. The internal strengthening component could change the failure mode from mode 1 to mode 2 and enhance the fire behavior of the SHS column connection when the thickness of the column wall was small. In the steady-state test, the resistance of the connection decreased obviously with the increase of the fire temperature. In transient-state test, the ductility and the failure temperature decreased obviously with the increase in load ratio. The internal component is an effective way to improve the fire behavior of the TOB bolted SHS column connection. The strengthened TOB bolted SHS column connection could replace SHB bolted connection with the same SHS column wall thickness under the same circumstance. Equations to calculate the yielding resistance of the TOB bolted SHS column connections at different temperatures were given. Comparison with test results showed the proposed equations could predict the failure mode of the TOB bolted connections precisely and predict the yielding load of the connections with acceptable accuracy.

Penguatan Tradisi Aswaja An-Nahdliyah

Abstract: This study reviews the strengthening of the Aswaja An-Nahdliyah tradition; efforts to counter the transnational Islamic movement. Talking about the transnational Islamic movement, it cannot be separated from the desire of the Islamist group. Such as Hizbut Tahrir Indonesia (HTI) and the Muslim Brotherhood (IM) to introduce Islam that really refers to the Qur'an and the Sunnah of the Prophet. The purpose of this study is to describe the transnational Islamic movement. Next, it describes the Aswaja An-Nahdliyah tradition in the context of internal strengthening of the Nahdliyin youth. Then, analyze the impact of strengthening the Aswaja An-Nahdliyah tradition in an effort to ward off transnational movements. This study uses a qualitative phenomenological approach (qualitative phenomenological approarch) which aims to describe the situation or phenomena that occur qualitatively descriptively. Data analysis techniques in this research are data collection, data reduction, data presentation, conclusion and verification. The results of this study are first, the pattern in the transnational Islamic movement is influenced by the transmission and transformation of knowledge, then the piety movement (politic of piety) and political movement. Second, the Aswaja An-Nahdliyah traditions are the pilgrimage to the grave, Yasinan and Tahlilan, Manaqiban and Maulid Nabi, Ruwahan or Nyadran, Istighosah, the tradition of Bulan Suro, Ngapati and Mitoni or Tingkepan, the tradition of the Month of Shafar. Third, in the tradition of Pilgrimage to the Grave, Tawassul teaches the value of humility and tawadlu'. With the Istighatsah tradition, it is able to strengthen Ukhuwah. As for Ukhuwah, which is embedded in Muslims, it will fend off everything that leads to violence that leads to radicalism. When Muslims get used to the Khotmil Qur'an tradition, Muslims will motivate themselves to learn and practice Islamic teachings. So, strengthening the Aswaja An-Nahdliyah tradition is one of the most effective vaccines in an effort to prevent and at the same time fight the infiltration of transnational Islamic movements.

Seismic behavior investigation of TOB bolted endplate connection with novel internal strengthening structure

This paper presents the results of the cyclic loading test on Thread-fixed One-side Bolts bolted Endplate Connection (TOBEC). Two types of novel strengthening structures including double H-shape stiffener and polygonal steel tube stiffener were applied to the connection to increase the length of the threads and improve the bending strength of the Hollow Square Column (HSC). Six full-scale specimens in total were designed to study the effect of the thickness of the strengthening structure sidewall/flange, and the thickness of the endplate on connection seismic performance. The failure modes, bending moment-rotation relationship, and the seismic performance of each specimen were analyzed and evaluated. Test results revealed that the strengthening structures could significantly improve connection mechanical performance. Meanwhile, the unwanted failure mode of hole thread failure and the column wall yielding failure could be avoided by utilizing strengthening structures moderately. Moreover, limited experimental results indicated that the double H-shaped stiffener was more effective in increasing the bending strength of the column wall. The strengthened connection could display satisfactory seismic performance in terms of rotation capacity, strength degradation, stiffness degradation, and energy dissipation.

EFFECTS OF WEB OPENINGS ON SHEAR BEHAVIOUR OF NORMAL AND INTERNALLY STRENGTHENED CONCRETE BEAMS

Web openings in reinforced concrete (RC) beams are provided to pass utility pipes and ducts through them. This causes high stresses (with local cracking) around the transverse web openings, which may lead to reduction in ultimate strength and stiffness of RC beams. Internal strengthening with shear reinforcement can increase ultimate strength of the beam with web openings. This paper presents an experimental study which was conducted to investigate load carrying capacity, mid-span deflection and failure modes of beams with web openings. A total of eighteen RC beams were included in the testing programme, which were tested under two-point loading. The beams contained both pre-planned and post-planned web openings. Experimental results showed that ultimate load of the beams decreased from forty-two to sixty-seven percent due to the presence of web openings in the shear zones. Shear strength of the beams with pre-planned web openings increased by thirty-six percent and one-hundred two percent as compared to the reference beam due to the increase of shear reinforcement by one-hundred twenty-two percent and three-hundred three percent, respectively. Similarly, increase in shear capacity up to six percent and fourteen percent was found for the beams with post-planned web openings due to the aforementioned increase in the area of shear reinforcement, respectively. The ultimate load carrying capacity was also compared with the theoretical models. Internal strengthening and pre planned opening were found effective for providing web openings in the beams.

Seismic performance of thread-fixed one-side bolts bolted extended endplate connection to HSST column with internal strengthening components

This paper presents experimental results of the seismic performance of the Thread-fixed One-side Bolts bolted Endplate Connection to Hollow Square Steel Tube column (TOBEC-HSST) with internal strengthening components. Five specimens were tested under cyclic loading. The main variable parameters affecting the seismic behavior of specimens were the internal strengthening structure types (i.e. the polygonal steel tube without inner stiffener, or with the horizontal or vertical stiffener) and the extended endplate types (i.e. with or without the endplate stiffeners). The failure modes of connections were observed, the moment-rotation hysteretic response and the strain distribution of connections were obtained. Besides, the rotation ability and ductility, the degradation of strength and rigidity, and the energy dissipation capacity were analyzed and compared, which were affected by the strengthening measures. The introduction of the endplate stiffeners can improve the overall rigidity of the joint region and sufficiently develop the energy dissipation capacity and ductility of the connections, and the contribution from the inner stiffener in the internal strengthening polygonal steel tube can also enhance the seismic performance of the connections. In addition, the rotations at the failure of the connection were larger than 30 mrad, which satisfied the ductility limitation requirement in reference to FEMA-350, revealing a potential to the application in seismic steel structures.