Optimum Design of Square Air-Core Electromagnetic Coil System

Designs of electromagnetic (EM) coil have attracted a lot of attention in the research community due to its applications in several areas of human endeavours. However, the optimal selection of coil wire size and current in the design of Square Air-Core Multi-turn Multilayer Electromagnetic Coil (SAMMEC) with significant wire diameter for both safe and cost-effective products has not been given enough research attention. Therefore, the equation for the flux density produced by a rectangular loop of wire was adopted in the modelling of SAMMEC with significant wire diameter. A coil design chart was constructed based on the developed model and design specifications. Both the feasible and non-feasible design regions and the line of optimum magnetic flux density were identified on the constructed chart. The appropriate wire size and current for the coil were both determined from the design-chart. The diameter, length, resistance, copper loss, and weight of the selected wire for the generation of 0.06 T flux density were found to be 0.00326 m, 267.01 m, 0.5502 Ω, 263.87 W, and 19.86 kg respectively. The selected wire can produce an optimum flux density of 0.066 T with current of 24 Amp and associated copper loss of 316.92 W. Keywords—Air core, Electromagnetic coil, Magnetic flux density, Multilayer, Multi-turn

Composite Polymer Coatings for Repair of Concrete Linings of Channels

The paper is dedicated to the results of research on composite polymer material used for concrete casings repair. Field approbation of new material was carried out on the irrigation channel test site during the repair of concrete coating deformation joints and cracks. The paper provides the obtained theoretical formulae and results of water permeability calculation in concrete casing cracks with smooth and rough walls. A design chart for determining water permeability of damages in the form of cracks of various coating width on channel concrete coatings was obtained. A universal nomogram was obtained for determining the water permeability of damage in the form of cracks of various opening widths on the concrete coverings of channels.

Evaluasi Tebal Perkerasan Lentur Akibat Beban Berlebih Dengan Metode Austroads Menggunakan Program Circly 6.0

Faktor utama terjadinya kerusakan jalan yaitu akibat dari angkutan barang yang membawa beban melebihi sumbu terberat suatu kendaraan (<em>Overload</em>). Penelitian ini dilakukan untuk membandingkan desain tebal perkerasan menggunakan beban standar dan akibat beban berlebih kendaraan. Metode Austroads digunakan dalam mendesain tebal perkerasan, sedangkan Program Circly 6.0 digunakan untuk mengevaluasi kemampuan tebal perkerasan tersebut dalam memikul beban. Data LHR dan beban kendaraan digunakan untuk menghitung nilai <em>Equivalent Standard Axle</em><em>s</em> (ESA), <em>Cumulative Growth Factor</em> (CGF), dan <em>Design Equivalent Standard Axle</em><em>s</em> (DESA), sehingga dapat diketahui jenis material dan tebal setiap lapis perkerasan menggunakan <em>Design Chart</em>. Dari hasil penelitian didapatkan tebal lapis perkerasan untuk umur rencana 20 tahun dengan CBR tanah dasar 5% untuk beban standar yaitu Lapis permukaan 17,5 cm (Aspal, Modulus 3000 MPa), Lapis pondasi atas 10 cm (Granular, Modulus 350 MPa), dan lapis pondasi bawah 25 cm (<em>Cemented Material</em>, Modulus 5000 MPa), sedangkan untuk beban berlebih dengan material yang sama, tebal perkerasan terdiri dari Lapis permukaan 22,5 cm, Lapis pondasi atas 10 cm, dan lapis pondasi bawah 20 cm. Beban berlebih yang digunakan dalam perhitungan masuk dalam kategori pelanggaran tingkat II (5-15%) dan tingkat III (&gt;25%). Dari Program Circly 6.0 dapat diketahui bahwa desain Lapis perkerasan untuk beban standar maupun beban berlebih sudah memenuhi standar dan aman untuk digunakan. Hal ini ditandai dengan nilai <em>Cumulative Damage Factor</em> (CDF) ≤1

IMPLEMENTASI METODOLOGI PERANCANGAN PERKERASAN COAL HAULING ROAD DI STA KM 37+000 – 37+300 BERDASARKAN MANUAL DESAIN PERKERASAN JALAN 2017 MENGGUNAKAN UKURAN AGREGAT TERTENTU

ABSTRAK Coal hauling road merupakan jalan utama yang dipergunakan untuk mengangkut batubara dari Pit ke Stockpile Port dengan jarak 48 Km menggunakan unit dump truck bermuatan 26 ton hingga 34 ton dengan target produksi 1.000.000 ton pertahun. Unit dump truck yang digunakan masuk ke dalam kategori truck 3 sumbu – sedang, dengan nilai faktor ekivalen beban atau Vehicle Damage Factor (VDF) sesuai dengan tabel dari Manual Perkerasan Jalan 2017. Jumlah lintas harian rata-rata (LHR) semua unit dump truck yang melintas dalam sehari mencapai 270 lintasan sehingga jumlah kumulatif beban gandar standar (CESA) dalam hal ini CESA pangkat 4 sebesar 12.86 x 106 dan CESA pangkat 5 sebesar 17.69 x 106.Secara visual dan kondisi yang ada california bearing ratio (CBR) tanah dasar coal hauling road lebih besar dari 6% maka tidak tidak diperlukan perbaikan tanah dasar. Struktur pengerasan berdasarkan ESA5 masuk ke dalam kategori Bagan Desain 3 dimana berdasarkan Bagan Desain 3, desain perkerasan jalan dilakukan dengan menggunakan pondasi agregat kelas A hingga menggunakan asphaltic concrete wearing course (AC WC). Secara aktual Bagan Desain 3 tidak dapat terpenuhi, sebagai alternatif adalah menggunakan Bagan Desain 5 dimana perkerasan jalan menggunakan 3 lapisan, yaitu lapis pondasi agregat kelas A, kelas B dan Burda (lapis penutup berupa laburan dengan ukuran 20 mm).Penerapan perkerasan jalan dengan mengunakan Bagan Desain 5, khususnya penggunaan agregat A di coal hauling road dipilih menggunakan ukuran 10 mm - 20 mm, 20 mm – 30 mm dan 30 mm – 50 mm sedangkan lapisan burda tidak digunakan. Penggunaan agregat modifikasi ini telah dilakukan di STA KM 37 dengan panjang jalan mencapai 300 meter. Tujuan dari penggunaan agregat modifikasi ini yaitu untuk menjaga traksi roda kendaraan dengan permukaan jalan, mempercepat slippery, mengurangi potensi jalan berdebu dan mengurangi perawatan jalan khususnya penggunaan unit grader. Kata kunci: Coal hauling Road, VDF, LHR, ESA, Manual Desain Perkerasan Jalan, Bagan Desain, Agregat ABSTRACT Coal hauling road is the main road used to transport coal from the Pit to Stockpile Port with a distance of 48 Km using dump trucks capacity 26 - 34 tons with a production target of 1,000,000 tons per year. The dump truck units used fall into the 3 axes - medium truck category, with the value of the Vehicle Damage Factor (VDF) in accordance with the table from the Road Pavement Manual 2017. The average daily traffic count (LHR) of all dump truck units passing in a day reaches 270 passes so that the cumulative number of standard axle loads (CESA) in this case CESA 4 is 12.86 x 106 and CESA 5 is 17.69 x 106.Visually and the existing condition of California bearing ratio (CBR) of subgrade coal hauling road is greater than 6%, there is no need for subgrade improvement. Based on ESA5 the hardening structure will use Design Chart 3 category. Based on Design Chart 3 the pavement design is carried out using aggregate foundation class A to using asphaltic concrete wearing course (AC WC). Actually Design Chart 3 cannot be fulfilled, as an alternative is to use Design Chart 5 where the pavement uses 3 layers, namely the aggregate foundation layers of class A, class B and Burda (the covering layer is a 20 mm diameter).The application of pavement using Design Chart 5, specifically the use of aggregate A in coal hauling road is chosen using sizes 10 mm - 20 mm, 20 mm - 30 mm and 30 mm - 50 mm while the burda layer is not used. The use of this modified aggregate has been carried out at STA KM 37 with a road length of up to 300 meters. The purpose of using this modified aggregate is to maintain vehicle wheel traction with the road surface, accelerate slippery, reduce the potential for dusty roads and reduce road maintenance, especially the use of grader units. Keywords: Coal hauling Road, VDF, LHR, ESA, Road Pavement Design Manual, Design Chart, Aggregate