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"Paper ini menyampaikan hasil studi eksperimen pada sambungan komposit yang terdiri dari pelat beton komposit, balok baja tipe I yang dilas terhadap kolom komposit concrete-filled tube (CFT). Parameter yang diteliti adalah rasio tulangan pelat, tebal kolom, presentase dari shear connectors dan pengaruh dari beton di dalam kolom."

"Indonesia merupakan negara yang sering terjadi gempa bumi dan letusan gunung berapi yang mengelilingi Samudera Pasifik. Diperlukan solusi bangunan tahan gempa seperti bangunan SMRF Special Moment Resisting Frame yang memiliki daktilitas tinggi. Penelitian yang dilakukan menggunakan program Drain-2DX yang dimodelkan secara 2 dimensi dengan analisis pushover. Bangunan menggunakan profil Wide Flange memiliki kekuatan dan daktilitas lebih besar dibandingkan dengan bangunan menggunakan profil Concrete Filled Steel Tube. Target sendi plastis mempengaruhi kekuatan, kekakuan dan daktilitas. Sebaiknya bangunan dirancang target sendi plastis pada beam karena memiliki kekuatan dan kekakuan yang besar secara global dan memiliki daktilitas yang cukup pada bangunan struktur SMRF.

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Indonesia is a frequent country of earthquakes and volcanic eruptions that surround the Pacific Ocean. Required earthquake resistant building solutions such as SMRF Special Moment Resisting Frame buildings that have high ductility. Research conducted using Drain 2DX program that is modeled in 2 dimension with pushover analysis.

Buildings using the Wide Flange profile have greater strength and ductility compared to buildings using Concrete Filled Steel Tube profiles. Preferably the building is designed to target plastic joints on the beam because it has great strength and stiffness globally and has sufficient ductility in the building of the SMRF structure."

"Paper ini menyampaikan hasil studi eksperimen pada sambungan komposit yang terdiri dari pelat beton komposit, balok baja tipe I yang dilas terhadap kolom komposit concrete-filled-tube (CFT).Parameter yang diteliti adalah rasio tulangan pelat, tebal kolom, persentase dari shear connectors dan pengaruh dari beton di dalam kolom. Hasil studi eksperimen menunjukkan bahwa tulangan pada pelatmemberikan efek kontinuitas yang parsial pada sambungan sehingga sambungan komposit yang diteliti pada studi ini bisadikategorikan sebagai sambungan semi - rigid. Paper ini juga menyajikan metode untuk memodelkan diagram momen-rotasi dari sambungan jenis ini dengan menggunakan model kurva tri-linear dan persamaan untuk mendefinisikan kekakuan rotasi awal (initial rotational stiffness) dan momen ultimate. Jika dibandingkan dengan hasil eksperimen, hasil yang didapat dengan menggunakanmodel dan persamaan yang diajukan memberikan hasil yang cukup dekat.

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AbstractThis paper presents the main results of an experimental study on composite connections comprising steel I -beam welded to concrete -filled-tube (CFT) column. The influences of reinforcement ratio, column thickness, percent age of shear connectors and the presence of concrete filled column are investigated. The experimental results indicate that reinforcements in the slab can provide the connectionwith partial continuity, such that composite connections with CFT column could be categorised as semi -rigid. A method to predict the moment rotation relationship of such composite connections isthen presented where a tri-linear moment-rotation model was chosen to represent its behaviour. The equations to define its initial rotational stiffness and ultimate moment resistance are derived. All theproposed equations are compared with the experimental observations and a reasonable good agreement is obtained."

"Indonesia merupakan kawasan rawan gempa dengan tingkat kepadatan penduduk yang tinggi. Sehingga dibutuhkan struktur bangunan yang mampu menyerap gaya gempa dengan baik, dari segi kekuatan, kekakuan, dan daktilitas. Bangunan dengan rangka Eccentrically Braced Frame merupakan salah satu sistem struktur yang memiliki energi disipasi yang baik dengan adanya elemen link beam dan bracing pada struktur rangkanya. Penggunaan material pada bangunan tahan gempa juga mempengaruhi kinerja struktur. Saat ini banyak bangunan tahan gempa yang memanfaatkan material baja dikarenakan sifatnya yang kuat, daktail, dan mampu menyerap energi. Material komposit Concrete Filled Steel Tube CFST memiliki kekuatan serta kekakuan yang diperkirakan mampu menahan gaya gempa. Analisis pushover digunakan untuk mengetahui kinerja suatu struktur bangunan, dalam hal ini menggunakan program Drain 2dx. Berdasarkan analisis pushover struktur bangunan komposit CFST tidak lebih kuat, kaku, dan daktail dibandingkan dengan bangunan baja WF. Hal itu dikarenakan pengaruh perbedaan luasan baja pada elemen komposit rata-rata hanya 46 dari elemen baja WF. Berdasarkan analisis yang dilakukan dengan modelisasi sambungan balok-kolom mengurangi rigiditas struktur, sehingga berpengaruh pada kekuatan yang lebih kecil, tetapi memiliki daktilitas yang lebih tinggi.

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Indonesia is an earthquake prone area with high population density level. It requires the study of building structures that can absorb earthquake energy, in terms of strength, stiffness, and ductility. Eccentrically Braced frame building is a structure system that has a good dissipation of energy with a bracing and link element that can make it stiffer, stronger, and more ductile.

Use of material on the earthquake resistant buildings can also affect the performance of the structure. Currently, many earthquake resistant buildings use steel material because of its strength, ductility, and its ability to absorb energy. Composite material, Concrete Filled Steel Tube CFST, has the strength and the stiffness that is estimated to be able to withstand the quake energy.

Based on pushover analysis, buildings with CFST composite material is not stronger, stiffer, and more ductile compared to steel material building. It is due to the difference of the steel area on the composite element is averagely only 46 of the steel area in steel WF element. Based on recent studies, by adding the beam column connection design to the structure, it can reduce the rigidity and strength, though it could increase the ductility. "

"ABSTRAKPenggwzaan material komposit sangai Iuas di berbafai bidang, aplikasi iiu antara lain kelautan, otomotgf pesawat terbang dan peralatan olah raga.Penggunaan material komposi! di Indonesia sangat cocok menginga! Indonesia sebagai negara riiaritim dan berilclim tropis dengan lrelembaban yang tinggi sehingga kerusalean akibat lcorosi dan biaya pemeliharaan yang ringgi dapai dihindari. Oleh lcarena ilu perlu dilakukan penelilihrz mengenai pengaruh linglczmgan rerhadap kekuaian mekanis kamposit berpenguat serat.Proses fabrikasi pada penelitian ini menggunakan hand lay-up method dengan cefakan berbeniulc panel. Resin epolrsi digzmalam sebagai marrik dan sebagai pengual digunalcan sera! gelas ripe E yang mempunyai lcetahanari terhadap Iinglcungan dan lcekuaian impalc yang firzggi.Pada penelilian ini sampel komposii dielcspos pada Nga lingkzmgan yang berbeda yaita tanpa pereridaman, perendaman air tawar dan perendaman air Iaut.Semua sampel juga diekspos dengan radiasi sinar ultra violet dan siklus temperatur selama 5 04 jam.Hasil penelitian menzmjukan bahwa sampel yang dielcfpos pada lingkungan akan mengalami perubahan berar karena absorpsi air. Absorpsi air terbesar terjadi pada sampel yang dieltspos pada perendaman air laur, untuk sample zji iarik dengan peruliahan berat rata-raia 3,1 93% dan sample uji impak 2, 457% Kelmatan tarik tampa perendaman yailu 120,923 N/mmz, /fekualan taril:perendaman air tawar 94,897 N/mm2 dan kekuatan iarik perendaman air law mencapai 93,974 N/mmz, sedanglfan harga impak tanpa perendaman mencapai 0. 0588 J/m.m2, Harga impak perendaman air tawar 0, 0523 J/mm? dim harga impak perendaman air /auf 0, 0462 J/mmz.Pengaruh lcombinasi perendaman, radiasi UV dan silclus' lemperatur alcarz menunmlcan kekuaian tarik dan impair, penuranan lrelzuatan tarik dan impalc karena ieqadi degradasi jisik dan kimia slrukrur komposil dengan malrir dominared degradation. Mode perparahan yang dominan akibat pembebanan tarilc dan impair adalah perpatahan iranslaminar dan intralaminar dengan bentuk kegagalan delaminasi, fiber pull-our dan relalc mah-ik

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"Performance-based design (PBD) untuk struktur bawah belum diperbolehkan di Indonesia karena terdapat syarat yang harus dipenuhi, yaitu limited ductility dan repairable. Definisi dari repairable sendiri belum dijelaskan secara detail sehingga diperlukan penelitian lebih lanjut mengenai maknanya. Penelitian perbaikan dilakukan terhadap benda uji sambungan spun pile terhadap pile cap yang sudah rusak parah dan diperbaiki menggunakan fiber reinforced polymer (FRP) berupa FRP rod dan FRP wrap. Pengujian dilakukan untuk spun pile dengan beton pengisi yang diperbaiki dengan sepuluh buah FRP rod dan dua lapis FRP wrap. Parameter yang dilihat dalam menentukan perilaku dan efektivitas perbaikan adalah kekuatan, daktilitas, energi disipasi, momen rotasi, degradasi kekakuan, dan degradasi kekuatan. Hasil penelitian menunjukan bahwa benda uji mampu kembali ke kondisi awal dengan adanya penurunan kekuatan. Damage index dan performance levels juga dianalisa untuk eksperimen dan setiap model yang dibuat. Berdasarkan hal tersebut, dapat diketahui bahwa jumlah FRP rod yang digunakan dan kondisi awal benda uji sebelum perbaikan akan mempengaruhi efektivitas perbaikan yang dilakukan. Model dengan kondisi awal sebelum perbaikan berupa serviceable dan repairable berdasarkan damage index, memberikan perbaikan yang paling efektif untuk kembali ke kondisi awal sambungan spun pile terhadap pile cap sebelum mengalami kerusakan.

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Performance-based design (PBD) is not allowed for lower structures in Indonesia because there are conditions that must be met, namely limited ductility and repairability. The definition of repairable itself has not been explained in detail so further research is needed on its meaning. Repair research was carried out on test specimens for spun pile connections to pile caps that were severely damaged and repaired using fiber reinforced polymer (FRP) in the form of FRP rods and FRP wrap. Tests were carried out for spun piles with infill concrete repaired with ten FRP rods and two layers of FRP wrap. Parameters considered in determining the behavior and effectiveness of repairs are strength, ductility, energy dissipation, rotational moment, stiffness degradation, and strength degradation. The results showed that the test object was able to return to its initial condition with a decrease in strength. Damage index and performance levels were also analyzed for the experiment and each model was created. Based on this, it can be seen that the number of FRP rods used and the initial condition of the test object before a repair will affect the effectiveness of the repairs carried out. The model with the initial conditions before repair in the form of serviceable and repairable based on the damage index provides the most effective repair to return to the initial condition of the spun pile-pile cap connection before it was damaged"

"A multi modelpredictive control and proportional-integral controller switching (MMPCPIS)approach is proposed to control a nonlinear distillation column. The study wasimplemented on a multivariable nonlinear distillation column (Column A). Thesetpoint tracking and disturbance rejection performances of the proposedMMPCPIS were evaluated and compared to a proportional-integral(PI) controller and the hybrid controller (HC). MMPCPIS developed to overcome theHC?s limitation when dealing with very large disturbance changes (50%). MMPCPIS provided improvements by 27% and 31%of the ISE (integral of square error) for feed flow rate andfeed composition disturbance changes, respectively, comparedwith the PI controller, and 24% and 54% of the ISE for feed flow rate and feedcomposition disturbancechange, respectively, compared with HC."

"Thepavement of the nailed-slab system has been proposed as analternative solution for addressing the rigid pavement problem in soft soils.This system is used for developing a rigid pavement. The simple method of using an equivalent modulus of subgrade reaction (k?) in nailed-slab system analysis wasproposed by a previous researcher. This modulus consists of the modulus of subgrade reaction from a plate load test(k) and an additional modulus ofsubgrade reaction due to pile installing (Dk). Theadditional modulus of subgrade reaction has been proposed by some authors. Thedisplacement factor was used in determining the additional modulus of subgradereaction. This factor is difficult to define. In this research, the prototypetest of a nailed slab with single-pile installation was conducted to learn thevalidation of the theory of the additional modulus of subgrade reaction on afull-scale dimension. The prototype was constructed on soft clay, and theconnection between the pile and slab was perfect monolithically. This systemwas loaded by centric load. A new curve of the displacement factor is proposed.Calculated deflections based on thiscurve were compared to the observed deflection andresulted in good agreement with the observation. Hence, it can be used in preliminary design."

"The main problem with the slurry process is the difficulty in recovering the photocatalyst nanoparticle from water following purification. An alternative solution proposed the photocatalyst be immobilized on magnetic carriers, which would allow them to be recollected from the water suspension following treatment using an external magnetic field. Magnetically photocatalyst composites were prepared using simple heteroagglomeration by applying attractive electrostatic forces between the nanoparticles with an opposite surface charge. The Fe3O4/SiO2/TiO2 photocatalysts were synthesized in an aqueous slurry solution containing Fe3O4/SiO2 and TiO2 nanoparticles under pH 5 conditions. Meanwhile, Fe3O4/SiO2 was prepared by a simple procedure via a coprecipitation of iron(II) and iron(III) ion mixtures in ammonium hydroxide and was leached by sodium silicate. The synthesized samples were investigated to determine the phase structure, the magnetic properties, and the morphology of the composites by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM), respectively. The results indicated that the composites contained anatase and rutile phases and exhibited a superparamagnetic behavior. Fe3O4/SiO2 particles, which were of the aggregation spherical form at 20 nm in size, were successfully attached onto the TiO2 surface. The catalytic activity of Fe3O4/SiO2/TiO2 composites was evaluated for the degradation of methylene blue under ultraviolet (UV) irradiation. The presence of SiO2 as a barrier between Fe3O4 and TiO2 is not only improves the photocatalytic properties but also provides the ability to adsorb the properties on the composite. The Fe3O4/SiO2/TiO2 (50% containing TiO2 in composite) were able to eliminate 87.3% of methylene blue in water through the adsorption and photocatalytic processes. This result is slightly below pure TiO2, which is able to degrade 96% of methylene blue. The resulting Fe3O4/SiO2/TiO2 composite exhibited an excellent ability to remove dye from water and it is easily recollected using a magnetic bar from the water. Therefore, they have high potency as an efficient and simple implementation for the dye effluent decolorization of textile waste in slurry reactor processes."

"Cold formedsteel has relatively high width-to-thickness ratio elements, which causes it tobuckle easily. Combining it with timber laminas would be an effective solutionfor reducing this buckling problem. This research focuses on the connectionsystem of a cold formed steel-timber composite, which was obtainedby attaching several timber laminas to the web part of cold formedsteel using screws. The connection used two bolts that were 8 mm in diameter,as well as two different kinds of side plates: steel and plywood. Cold formedsteel 75Z08 and Swietenia mahagoni(moisture content 12.2%; specific gravity 0.77) were used for connections andwere loaded in parallel and perpendicular directions. In addition, theconnections of cold formed steel (without timber laminas) usingself-drilling screw fasteners were tested until failure. Numerical analysispredicting the load-slip curve and apparent yield load of the composite joints wascarried out using the DOWEL program and the European Yield Theory,respectively. The test results showed that the connection system with steelside plates is capable of accommodating the strength increase of compositemember, as it has a maximum load carrying capacity and initial slip modulus ofabout 4.5 and 2 times larger than those of the cold formed steel connections, respectively. In the caseof a connection system with plywood side plates, its joint properties aresimilar to those of the cold formed steel connection, except that it has largerjoint deformation."