@article{65c,
title = {Kajian dan Evaluasi Struktur Slab Prestressed Precast Modular Concrete},
author = {Gusti Lanang Bagus Eratodi and Ali Awaludin and Ay Lie Han and Andreas Triwiyono},
url = {https://ejournal.undip.ac.id/index.php/mkts/article/view/27765},
doi = {https://doi.org/10.14710/mkts.v26i1.27765},
year = {2020},
date = {2020-07-30},
journal = {Media Komunikasi Teknik Sipil},
volume = {11},
number = {3},
abstract = {Slab prestressed precast modular concrete berfungsi rigid pavement, mendukung beban kendaraan di atasnya pada tanah dasar yang daya dukungnya relatif rendah. Slab ini berukuran 2000 x 850 x 150 mm3 dari beton bertulang biasa (produksi lama) atau beton pretension (produksi baru) mutu beton K-500. Dalam pemakaian di lapangan slab ini diharapkan dapat dipasang dan dilepas berulangkali. Setelah beberapa kali pemakaian, terjadi kerusakan terutama pada bagian ujung slab berupa spalling. Tujuan kajian dan evaluasi struktur ini adalah: (1) mengamati kerusakan; (2) mendapatkan data kualitas bahan; (3) melakukan pemodelan secara numeris dengan memperhatikan sifat material, pembebanan dan kondisi tanah; dan (4) memberikan rekomendasi desain slab meliputi bahan dan geometrik. Metode kajian dan evaluasi kerusakan slab dilakukan pengamatan kerusakan, pengambilan core-case beton dan pengujiannya di laboratorium, serta pemodelan struktur slab dengan berbagai parameter (data tanah, mutu beton dan geometri slab). Hasil pengamatan di lapangan dan hasil analisis maka dapat diketahui bahwa spalling beton slab terjadi awalnya pada bagian tepi (sisi lebar 850 mm) yang selanjutnya menyebabkan efektifitas gaya pretension menjadi tidak optimal dan akhirnya volume spalling beton menjadi semakin bertambah. Selain karena frekuensi benturan saat pemasangan dan deformasi slab saat mendukung beban kendaraan. Permasalahan spalling beton juga dikarenakan mutu beton yang tidak sesuai.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{64c,
title = {Effect of specimen gauge reduction on uniaxial tension properties of reinforcing steel},
author = {A. Triwiyono and A.L. Han and S. Tudjono and A. Aryanto and B.S. Gan},
url = {https://link.springer.com/article/10.1007/s42243-020-00458-1},
doi = {https://doi.org/10.1007/s42243-020-00458-1},
year = {2020},
date = {2020-07-27},
journal = {Journal of Iron and Steel Research International},
abstract = {The Standard Test Methods for Tension Testing of Metallic Materials (ASTM E8) mandates a specimen gauge reduction for obtaining the tensile properties of reinforcing steel bars. The standard outlines the specimen preparation requirements and methods to ensure that test results well represent the material properties. On the other hand, some codes differ regarding the approach to specimen preparation. They do not apply gauging, for both deformed and plain steel bars. Thus, the effect of specimen gauge reduction on the tensile properties of reinforcing steel bars was evaluated, and the interconnection of properties to the layer hardness was analysed. The experiment governed a range of deformed hot-rolled bar sizes, tested in tension using precision instruments. The Rockwell hardness test was implemented layerwise on the specimen’s cross section, and the hardness number (HRC) was measured as a function of the layer distance to the centre. A finite element model was constructed to study the stress concentrations induced by a constant indentation, simulating the HRCs, and to numerically construct the stress–strain relationship of ungauged steel bars based on the core properties and the section HRC relationship. Scanning electron microscopy readings were performed to visually and chemically justify the results. It was shown that the specimen gauge reduction significantly influenced the resulting stress–strain behaviour of the material, and the yield and ultimate strengths were reduced. It was also demonstrated that the hardness response is proportional to the distance to the specimen’s axes. The corresponding yield and ultimate strengths thus increased accordingly, from the inner to the outer layers of the bar. Testing a gauged specimen will therefore result in lower strength than that of an ungauged steel bar.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{71,
title = {Compressive Strength Analysis On Geopolymer Paving By Using Waste Substitution Of Carbide Waste And Fly Ash},
author = {Mochammad Qomaruddin and Han Ay Lie and Arif Hidayat and Sudarno and Anik Kustirini},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/1424/1/012052/meta},
doi = {https://doi.org/10.1088/1742-6596/1424/1/012052},
year = {2020},
date = {2020-07-20},
journal = {Journal of Physics: Conference Series},
volume = {1424},
abstract = {The method to make paving sample in this research was done by mixing fly ash, carbide waste, sand, and alkali activator in the form of sodium silicate (Na2SiO3), 8M and 12M sodium hydroxide (NaOH) with ratio 1 : 2 as the binder, then it was pressed by using hydraulic press machine. The paving was made in the size of 20 cm x 10 cm x 6 cm with mix composition of 70% fine aggregate, 30% binder and activator from paving weight. The percentage of binder and activator was 65% and 35%, respectively. The curing was done by using wet burlap sack for about 28 days. After that, the compressive strength test was done. From the result of the compressive strength test of geopolymer paving sample can be concluded that the mixed test of carbide waste and fly ash (10 %: 90%) produced 34,6 MPa, and 39,8 MPa for its compressive strength.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{63b,
title = {The Behavior of Reinforced Concrete Members with Section Enlargement Using Self-Compacting Concrete},
author = {Nuroji Nuroji and Chung-Chan Hung and Blinka Hermawan Prasetya and Aylie Han},
url = {https://www.praiseworthyprize.org/jsm/index.php?journal=irece&page=article&op=view&path%5B%5D=24440},
issn = {2036-9913 },
year = {2020},
date = {2020-07-07},
journal = {IRECE},
volume = {11},
number = {3},
abstract = {This paper presents the experimental results of section enlargement effects on prismatic reinforced concrete members. 125 by 200 mm reinforced concrete members with a compressive strength of 20.3 MPa reinforced with D12 steel bars having a yield stress of 335 MPa situated in the tension and compression area, were produced. Two specimens were prepared, the first functioning as the control element and designated as the control beam (CB). The second strengthened with a section enlargement using self-compacting concrete (SCC) marked as the strengthened beam (SB). The SCC had a 28-day compressive strength of 23.9 MPa. The dimensions of the enlarged beam were 200 by 300 mm. The two specimens CB and SB were tested with a two-point loading system. Based on the tests data, the load–displacement and moment–curvature relationships characterizing the beams were generated. From the results it was concluded that the enlargement affected the load-carrying capacity and stiffness positively. The SB member had a six times higher moment capacity, while the stiffness performance was enhanced seven times when compared to the CB specimen. On the other hand, it was also demonstrated that the ductility of the SB decreased as a consequence of the increase in span-to-depth ratio. The study was expanded based on the rational analyses to evaluate the influence of the additional tensile steel and concrete strength ratio of the enlarged section.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{62b,
title = {Machining Parameter Optimization of EVA Foam Orthotic Shoe Insoles},
author = {Paulus Wisnu Anggoro, Abet Adhy Anthony, Mohammad Tauviqirrahman, Jamari, Athanasius Priharyoto Bayuseno, Aylie Han},
url = {http://ojs.imeti.org/index.php/IJETI/article/view/ijeti.2020.5099/968
http://ojs.imeti.org/index.php/IJETI/issue/view/87
http://ojs.imeti.org/index.php/IJETI/article/view/ijeti.2020.5099},
doi = {https://doi.org/10.46604/ijeti.2020.5099},
issn = {2226-809X},
year = {2020},
date = {2020-07-01},
journal = {International Journal of Engineering and Technology Innovation},
volume = {10},
number = {3},
abstract = {In this study, ethylene-vinyl acetate (EVA) foam orthotic shoe insoles with different surface roughnesses (Ra)
are investigated in terms of CNC milling strategy. Based on a hybrid Taguchi-response surface methodology
(TM-RSM) approach, machining parameters, including tool path strategy, spindle speed, feed rate, and step over, as
well as material hardness, are of particular interest. The main aim of this work is to develop mathematical models
and determine the optimum machining parameters. Experiments are conducted on a CNC milling machine with a
standard milling cutter and run under dry coolants. The optimal conditions are established based on TM and then
used to determine the optimum values in the RSM modeling. The main finding of the present work is that there are
significant improvements in the Ra, by up 0.24% and 4.13%, and machining time, by up 0.43% and 0.41%, obtained
with TM-RSM in comparison to TM analysis.
},
keywords = {},
pubstate = {published},
tppubtype = {article}
}