Pujo Aji | Institut Teknologi Sepuluh Nopember (original) (raw)

Papers by Pujo Aji

This study focuses on development of Artificial Neural Networks (ANNs) in prediction of initial s... more This study focuses on development of Artificial Neural Networks (ANNs) in prediction of initial setting time of self compacting concrete (SCC). To predict the setting time of SCC six input parameters are identified. A total of 250 different data sets of SCC was collected from the ready-mix factory and concrete laboratory in Surabaya. Training data sets comprises 120 data entries, and the remaining data entries (130) are divided between the testing and validation sets. Different combinations of architecture, number of neurons in hidden layer, different coefficient for learning rate and momentum were considered and the results were validated using an independent validation data set. A detailed study was carried out, considering one hidden layer for the architecture of ANN. The performance of the 6-3-1 architecture was the best possible architecture. The error for the training set was 4.32 percent for the 120 training data points, at running time 41.765 seconds, 2.54 percent for the 80...

Jurnal Teknik ITS, 2012

Penambahan fly ash dan penggunaan steam curing membuat produksi beton lebih ekonomis, baik dari s... more Penambahan fly ash dan penggunaan steam curing membuat produksi beton lebih ekonomis, baik dari segi waktu maupun biaya. Selain ekonomis, kualitas beton juga harus dikontrol, salah satunya adalah kuat tekan. Di Indonesia prediksi kuat tekan beton diatur PBI 1971. Peraturan ini hanya dapat digunakan untuk prediksi kekuatan beton normal, sehingga tidaklah akurat jika peraturan ini kita gunakan untuk memprediksi kuat tekan beton berbahan campuran fly ash yang dirawat dengan steam curing . Sebagai solusinya Day (2006) mengusulkan prediksi menggunakan metode kematangan ( maturity method ). Penelitian ini mencoba memprediksi kuat tekan beton umur 7, 14 dan 28 hari berdasarkan data kuat tekan dan faktor waktu-suhu umur umur dasar 1 dan 2 hari. Benda uji beton yang digunakan berbentuk silinder 15 x 30 cm, berbahan campuran fly ash tipe F dan dirawat dengan perawatan uap ( steam curing ). Dari hasil penelitian ini diketahui nilai error antara kuat tekan prediksi dengan kuat tekan aktual kura...

Jurnal Teknik ITS, 2012

Kehalusan, strength activity index dan berat jenis fly ash mempunyai pengaruh yang signifikan ter... more Kehalusan, strength activity index dan berat jenis fly ash mempunyai pengaruh yang signifikan terhadap hasil kuat tekan mortar. Perlu dilakukan penelitian untuk mencari pengaruh sifat-sifat tersebut dengan mengetahui hubungan antara sifat fisik fly ash dengan kuat tekan mortar. Artificial Neural Network (ANN) merupakan suatu model komputasi yang bekerja seperti sel saraf biologis pada otak manusia, dipakai untuk mencari hubungan tersebut melalui proses pembelajaran Back-Propagation . Langkah-langkah penelitian meliputi pengumpulan data, pemodelan, dan pengujian pemodelan yang sudah dibuat. Kehalusan, berat jenis dan strength activity index dipakai sebagai input dan kuat tekan mortar umur 28 hari sebagai target output dalam pemodelan. Pengujian dilakukan untuk mencari performa ANN yang paling optimal pada proses pelatihan dengan nilai Mean Square Error (MSE) validation terkecil . Dari penelitian yang telah dilakukan disimpulkan bahwa ANN dapat digunakan untuk membentuk hubungan antar...

A new optimization procedure for designing a steel frame structure is presented in this paper. A ... more A new optimization procedure for designing a steel frame structure is presented in this paper. A repaired or “modified” chromosome in genetic algorithm is intoduced in the optimization procedure. The proposed method is applied to two stuctural models. The first model is a three storey ordinary steel structure moment frame designed according to AISC-ASD, while the second one is a three storey eccentrically steel braced frame designed according to AISC-LRFD. From the analysis carried out, it is concluded that the optimization process of using repaired chromosome in the genetic algorithms results a better solution than an ordinary genetic algorithms. The new proposed method is more stable, reliable and faster in computing process; furthermore, it gives a lighter or less structural weight.

Jurnal Teknik ITS, 2012

Blending agregat merupakan proses untuk menentukan proporsi yang tepat dari agregat yang kemudian... more Blending agregat merupakan proses untuk menentukan proporsi yang tepat dari agregat yang kemudian dicampur sehingga dapat ditemukan gradasi atau susunan besar butir agregat yang sesuai dengan spesifikasi batasan yang ada. Blending agregat dapat diselesaikan menggunakan beberapa metode, diantaranya metode coba-coba, metode grafis dan metode optimasi. Di Indonesia, penyelesaian blending agregat masih dikerjakan secara manual (metode coba-coba dan metode grafis). Dengan menggunakan metode tersebut dibutuhkan waktu yang cukup lama untuk mengetahui hasil dari proses blending agregatnya. Tujuan dari penelitian ini adalah dapat dibuat sebuah program yang bisa menjalankan proses blending agregat dengan cepat, baik itu untuk agregat halus maupun agregat kasar. Salah satu metode yang dapat digunakan untuk menyelesaikan permasalahan tersebut adalah dengan menggunakan algoritma genetika. Algoritma Genetika merupakan metode optimasi yang dikembangkan berdasarkan pada teori evolusi biologi. Pada...

Pengujian untuk mengetahui kuat tekan beton di lapangan membutuhkan waktu 28 hari, terhitung saat... more Pengujian untuk mengetahui kuat tekan beton di lapangan membutuhkan waktu 28 hari, terhitung saat awal pembuatan benda uji. Waktu yang panjang menyebabkan penentuan kuat tekan beton sebagai penentu untuk kontrol kualitas menjadi lama, apalagi bila pembuatan struktur/bangunan membutuhkan volume beton yang besar dengan masa penyelesaian yang pendek.Untuk mengatasi waktu yang panjang diperlukan alat mempercepat proses pematangan beton (curing) agar dapat ditentukan kuat tekannya dalam waktu lebih pendek. Alat ini dapat membuat pematangan beton lebih cepat, hanya 5 jam, dibanding 28 hari prosedur standar, dan dapat berfungsi sebagai alat test rangkak tekan beton. Untuk keperluan mempercepat pematangan beton, juga dilengkapi dengan tambahan berupa cetakan benda uji dengan ukuran tertentu, alat pemanas untuk menaikkan suhu beton di dalam selinder, menggunakan pemanas listrik 1500 watt, alat ini diletakkan melingkupi cetakan silinder beton dan diberi aliran listrik dengan bantuan pengontro...

Jurnal Aplikasi Teknik Sipil, 2021

Journal of Civil Engineering, 2019

This paper presents nonlinear finite element analysis of eccentrically loaded circular Reinforced... more This paper presents nonlinear finite element analysis of eccentrically loaded circular Reinforced Concrete (RC) column confined with Carbon Fiber Reinforced Polymer (CFRP) wraps. The concrete constitutive model uses a plasticityfracture model which is restraint sensitive, utilize a non-constant plastic dilation rate, and is able to simulate the plastic volumetric compaction of concrete core under high confining pressure. For validation of the models, two available specimens from the literature are used in the validations. Excellent agreement between the numerical models and the available test results are obtained in this study. A detailed investigation on the confinement effectiveness of both external and internal confining devices are presented and discussed. This discussion of the confinement effectiveness is important to be included in the design formula.

IOP Conference Series: Earth and Environmental Science, 2020

For concrete planners and salt farmers know the distribution of sulfate in sea water becomes very... more For concrete planners and salt farmers know the distribution of sulfate in sea water becomes very important as a basis for the manufacture of concrete and as a planning analysis of salt-making. Based on this need to be done mapping the distribution of sulfate concentrations in surface sea water. In addition to the way the analysis in the laboratory, suspected sulfate can be done using an estimation algorithm as a remote sensing technique that results are presented in the form of geographic information systems. With remote sensing techniques will be obtained regional information sulfate at the sea surface since using Landsat 8 satellite recording results.The mapping of sulfate in the straits of Madura Island with Landsat 8 OLI imagery on July 26, 2018, obtained the minimal value was 2078.89 and the maximal value 2429.89.The highest sulfate concentration is in the Ujung-Kamal port area.When using SNI 2847: 2013 / ACI 318M-11 sulfate exposure in the Madura Strait includes a class of S2...

IPTEK Journal of Proceedings Series, 2017

Although the utilization of high-strength concrete and high-strength steel can reduced column dim... more Although the utilization of high-strength concrete and high-strength steel can reduced column dimension at high-rise building, the column aspect ratio remain low. These column were tended to dominate by shear failure than flexure failure. The research discusses the numerical analysis of shear critical of Highstrength reinforced concrete columns. The Uniaxial Shear Flexure Method (USFM) was used to observe this behavior and examined on the test result. This study showed that USFM method provided conservative prediction. Some modification was proposed in order to improve this method when estimate the shear behaviour of high-strength reinforced concrete column.

IPTEK Journal of Proceedings Series, 2017

This research discusses the role of transverse reinforcement as seismic reinforced concrete colum... more This research discusses the role of transverse reinforcement as seismic reinforced concrete columns confinement. The latest confinement design addressed for columns remains standing under certain level of axial compression and displacement demands. However, this purpose did not consider shear effect. An approach formulation to determine the amount of confinement for reinforcement concrete that account effect of shear is provided. This method is based on combined effects of axial and shear stress that found in coulomb failure criterion. The proposed formulation are tested in 163 column test result data base and compared with several building codes. The result showed that the formulation can reduce amount of confinement safely for most columns.

E3S Web of Conferences, 2020

During an earthquake, Reinforced Concrete (RC) building structures should behave in a ductile man... more During an earthquake, Reinforced Concrete (RC) building structures should behave in a ductile manner to prevent the structures from collapse. Therefore, the column element should have sufficient ductility to sustain an axial load at the post-peak region. Ductility of the RC column can be sufficiently provided by confinement to the RC column core. Therefore, in this paper, ductility of square RC columns made of NSC and HSSCR are analyzed using three-dimensional nonlinear finite element analysis (3D-NLFEA) with various ties configurations. In total, 12 specimens for each transverse steel rebar configuration were examined. The measurement used for ductility comparisons is the I10 index (AS 3600-2018) which is compared with the concept of ductility available in the literature (for example ACI 318-14). The study found that the computed minimum transverse steel rebar diameter based on ACI 318-14 showed larger diameter than the AS 3600:2018. From the 3DNLFEA analysis found that using a con...

E3S Web of Conferences, 2020

The use of steel fiber in concrete material can improves both the strength and the ductility of c... more The use of steel fiber in concrete material can improves both the strength and the ductility of concrete. The fibers can postpone or mitigate the concrete cover spalling under severe loading conditions such as during an earthquake. In this paper, the behavior of Steel Fiber Reinforced Concrete (SFRC) under compression is modeled using the Attard and Setunge’s stress-strain model. The parameter identification consisted of the elastic modulus (Ec), the peak strength (/cc), the residual strength (fes), and the peak strain of concrete under compression (ecc). From the investigation, it is found that the models proposed for active confined concrete can be applied for steel fiber reinforced concrete. It was also shown that the axial strain at peak stress increases as the fiber volumetric ratio and fiber aspect ratio increased. A simple formula to predict the approximate value of confining pressure to account for the steel fiber presence is proposed. The verification of the proposed model ...

Composite Structures, 2018

Strengthening reinforced concrete (RC) columns with external confining devices such as FRP wraps ... more Strengthening reinforced concrete (RC) columns with external confining devices such as FRP wraps or steel tube is widely used in construction. By using external confining devices, both the strength and ductility of RC columns are significantly improved. However, numerical modelling to predict the capacity of strengthened RC columns is limited and often oversimplified. One of the biggest challenges in numerical modelling is to deal with unequal dilation between the concrete inner core (enclosed by both transverse steel and FRP wraps) and the concrete outer core (between the transverse steel and FRP wraps). Inaccurate modelling on the concrete dilatant behavior can lead to incorrect strength prediction. Sophisticated constitutive models which are able to model concrete dilation and robust modelling techniques are required. In this paper, three-dimensional non-linear finite element analysis (3D-NLFEA) of circular RC columns confined with conventional steel stirrups and FRP wraps is presented. In the FEA, the initial stiffness method with Process Modification (acceleration technique) is used to solve the equilibrium forces in the global solution. The constitutive model is based on the plasticity formulation proposed by the authors, which can capture the effective lateral modulus   L E of the confining devices. This lateral modulus is obtained by observing the principal incremental stresses and strains at each element gauss point. It 2 was found that, the lateral modulus is greatly affected by the boundary condition, dilatant behaviour of the constitutive model and the Poisson's ratio of the external confining device. To validate the performance of the proposed model, several comparisons of the proposed model, using 3D-NLFEA, with experimental results is presented. The comparisons show that the predicted response using 3D-NLFEA and the experimental results of RC columns confined with FRP are in a good agreement.

IPTEK Journal of Proceedings Series, 2017

This paper presents a study of Rapid Visual Screening (RVS) using FEMA 154 and applied in Indones... more This paper presents a study of Rapid Visual Screening (RVS) using FEMA 154 and applied in Indonesia based on SNI 1726. RVS is a method to asses potential earthquake hazard of a building based on visual observation ("sidewalk survey") of the exterior and interior building if possible, and a Data Collection Form. This study is intended to see how important the RVS of the FEMA 154 can be implemented in Indonesia with a case study at Yogyakarta. The buildings that reviewed were assumed to have the same parameters as mention in FEMA 154 and compatible with SNI 1726 (Indonesian earthquake map). The results from field survey were compared to the numerical analysis. From the case study, it was found that the administration building of ATK Academy, the dormitory building of Ministry of Internal Affairs, the office building of Department of Agriculture, and the educational building of Health Polytechnics have a score more than 2, and the buildings are also declared safe according to SNI 1726.

Liniear Programming Untuk Optimasi Keuntungan Usaha Tani Daerah Irigasi Blega Madura, Dec 23, 2008

Kebutuhan air Daerah Irigasi Blega dipasok oleh waduk Blega. Daerah irigasi ini mempunyai luas 12... more Kebutuhan air Daerah Irigasi Blega dipasok oleh waduk Blega. Daerah irigasi ini mempunyai luas 1240.4 Ha, yang terletak di kabupaten Bangkalan, Madura, Jawa Timur. Seiring dengan berkembangnya wilayah Madura, waduk Blega merupakan salah satu dari target pemerintah sebagai sarana untuk memperluas jaringan irigasi teknis. Pada daerah studi sebagian besar lahanya masih sawah tadah hujan. Sehingga dengan dibangunya waduk ini akan dapat meningkatkan pendapatan petani dan memperbaiki sistem jaringan irigasi. Dengan kebutuhan air irigasi yang berbeda sepanjang tahun, yaitu tinggi pada musim kemarau dan kecil pada musim penghujan, Maka perlu dilakukan optimasi untuk mengatur air yang tersedia pada waduk, agar dapat dimanfaatkan semaksimal mungkin untuk irigasi dan mendapatkan keuntungan yang maksimum pada pola tanamnya. Optimasi yang akan dilakukan pada daerah studi menggunakan liniear programming dengan program bantu QM for Window 2. Liniear programming ini mempunyai keunggulan dibandingkan dengan cara konvensional. Metode ini menghapus proses coba-coba (trial and error) pada perubahan-perubahan desain dan resimulasi perubahan desain, merubah parameter-parameter desain secara otomatis, dan mempunyai penampilan yang matematis yang dapat mengambarkan responnya pada masukan-masukan sistem berbagai parameter desain. volume andalan yang ada dan kebutuhan air untuk masing-masing pola tanam yang direncanakann sebagai fungsi tujuan yang digunakan sebagai input pengoperasian program liniearnya. Dan fungsi tujuannya adalah keuntungan usaha tani. Output dari analisa ini adalah luas lahan sawah yang bisa ditanami untuk tiap-tiap jenis tanaman dan keuntungan maksimum hasil usaha tani yang diperoleh. Dari beberapa pola tanam yang direncanakan, dan awal musim tanam yang berbeda-beda. Diperoleh pola tanam yang paling menguntungkan yaitu padi-polowijo-polowijo dengan awal tanam November dekade I. Keuntungan yang diperoleh selama satu tahun masa tanam yaitu Rp 9,100,683,000.00 dengan intensitas tanaman sebesar 300%..

Penentuan lendutan (defleksi) struktur pelat menggunakan teori Kirchhoff dan Mindlin merupakan ka... more Penentuan lendutan (defleksi) struktur pelat menggunakan teori Kirchhoff dan Mindlin merupakan kajian utama tesis. Teori Kirchhoffmenetapkan tiga persamaan regangan, sedangkan path teori Mindlin lima rumusan persamaan regangan termasuk regangan geser transversal. Solusi dari kedua teori ini diproses dengan metoda elemen hingga, yang mana untuk meraldt matriks kekakuan elemen digunakan cara energi potensial minimum. Kajian analisis dibatasi dalam sistem energi konservatif, berlakunya kondisi elastik sempurna tanpa pengaruh temperatur. Digunakan program komputer dengan bahasa C++ untuk mendapatkan hasil analisis. Verifikasi hasil dengan program SAP 2000, menunjukkan tingkat akurat yang lebih baik dari teori Mindlin untuk mesh elemen setara.

Beton Stahlbetonbau, 2005

This study focuses on development of Artificial Neural Networks (ANNs) in prediction of initial s... more This study focuses on development of Artificial Neural Networks (ANNs) in prediction of initial setting time of self compacting concrete (SCC). To predict the setting time of SCC six input parameters are identified. A total of 250 different data sets of SCC was collected from the ready-mix factory and concrete laboratory in Surabaya. Training data sets comprises 120 data entries, and the remaining data entries (130) are divided between the testing and validation sets. Different combinations of architecture, number of neurons in hidden layer, different coefficient for learning rate and momentum were considered and the results were validated using an independent validation data set. A detailed study was carried out, considering one hidden layer for the architecture of ANN. The performance of the 6-3-1 architecture was the best possible architecture. The error for the training set was 4.32 percent for the 120 training data points, at running time 41.765 seconds, 2.54 percent for the 80...

Jurnal Teknik ITS, 2012

Penambahan fly ash dan penggunaan steam curing membuat produksi beton lebih ekonomis, baik dari s... more Penambahan fly ash dan penggunaan steam curing membuat produksi beton lebih ekonomis, baik dari segi waktu maupun biaya. Selain ekonomis, kualitas beton juga harus dikontrol, salah satunya adalah kuat tekan. Di Indonesia prediksi kuat tekan beton diatur PBI 1971. Peraturan ini hanya dapat digunakan untuk prediksi kekuatan beton normal, sehingga tidaklah akurat jika peraturan ini kita gunakan untuk memprediksi kuat tekan beton berbahan campuran fly ash yang dirawat dengan steam curing . Sebagai solusinya Day (2006) mengusulkan prediksi menggunakan metode kematangan ( maturity method ). Penelitian ini mencoba memprediksi kuat tekan beton umur 7, 14 dan 28 hari berdasarkan data kuat tekan dan faktor waktu-suhu umur umur dasar 1 dan 2 hari. Benda uji beton yang digunakan berbentuk silinder 15 x 30 cm, berbahan campuran fly ash tipe F dan dirawat dengan perawatan uap ( steam curing ). Dari hasil penelitian ini diketahui nilai error antara kuat tekan prediksi dengan kuat tekan aktual kura...

Jurnal Teknik ITS, 2012

Kehalusan, strength activity index dan berat jenis fly ash mempunyai pengaruh yang signifikan ter... more Kehalusan, strength activity index dan berat jenis fly ash mempunyai pengaruh yang signifikan terhadap hasil kuat tekan mortar. Perlu dilakukan penelitian untuk mencari pengaruh sifat-sifat tersebut dengan mengetahui hubungan antara sifat fisik fly ash dengan kuat tekan mortar. Artificial Neural Network (ANN) merupakan suatu model komputasi yang bekerja seperti sel saraf biologis pada otak manusia, dipakai untuk mencari hubungan tersebut melalui proses pembelajaran Back-Propagation . Langkah-langkah penelitian meliputi pengumpulan data, pemodelan, dan pengujian pemodelan yang sudah dibuat. Kehalusan, berat jenis dan strength activity index dipakai sebagai input dan kuat tekan mortar umur 28 hari sebagai target output dalam pemodelan. Pengujian dilakukan untuk mencari performa ANN yang paling optimal pada proses pelatihan dengan nilai Mean Square Error (MSE) validation terkecil . Dari penelitian yang telah dilakukan disimpulkan bahwa ANN dapat digunakan untuk membentuk hubungan antar...

A new optimization procedure for designing a steel frame structure is presented in this paper. A ... more A new optimization procedure for designing a steel frame structure is presented in this paper. A repaired or “modified” chromosome in genetic algorithm is intoduced in the optimization procedure. The proposed method is applied to two stuctural models. The first model is a three storey ordinary steel structure moment frame designed according to AISC-ASD, while the second one is a three storey eccentrically steel braced frame designed according to AISC-LRFD. From the analysis carried out, it is concluded that the optimization process of using repaired chromosome in the genetic algorithms results a better solution than an ordinary genetic algorithms. The new proposed method is more stable, reliable and faster in computing process; furthermore, it gives a lighter or less structural weight.

Jurnal Teknik ITS, 2012

Blending agregat merupakan proses untuk menentukan proporsi yang tepat dari agregat yang kemudian... more Blending agregat merupakan proses untuk menentukan proporsi yang tepat dari agregat yang kemudian dicampur sehingga dapat ditemukan gradasi atau susunan besar butir agregat yang sesuai dengan spesifikasi batasan yang ada. Blending agregat dapat diselesaikan menggunakan beberapa metode, diantaranya metode coba-coba, metode grafis dan metode optimasi. Di Indonesia, penyelesaian blending agregat masih dikerjakan secara manual (metode coba-coba dan metode grafis). Dengan menggunakan metode tersebut dibutuhkan waktu yang cukup lama untuk mengetahui hasil dari proses blending agregatnya. Tujuan dari penelitian ini adalah dapat dibuat sebuah program yang bisa menjalankan proses blending agregat dengan cepat, baik itu untuk agregat halus maupun agregat kasar. Salah satu metode yang dapat digunakan untuk menyelesaikan permasalahan tersebut adalah dengan menggunakan algoritma genetika. Algoritma Genetika merupakan metode optimasi yang dikembangkan berdasarkan pada teori evolusi biologi. Pada...

Pengujian untuk mengetahui kuat tekan beton di lapangan membutuhkan waktu 28 hari, terhitung saat... more Pengujian untuk mengetahui kuat tekan beton di lapangan membutuhkan waktu 28 hari, terhitung saat awal pembuatan benda uji. Waktu yang panjang menyebabkan penentuan kuat tekan beton sebagai penentu untuk kontrol kualitas menjadi lama, apalagi bila pembuatan struktur/bangunan membutuhkan volume beton yang besar dengan masa penyelesaian yang pendek.Untuk mengatasi waktu yang panjang diperlukan alat mempercepat proses pematangan beton (curing) agar dapat ditentukan kuat tekannya dalam waktu lebih pendek. Alat ini dapat membuat pematangan beton lebih cepat, hanya 5 jam, dibanding 28 hari prosedur standar, dan dapat berfungsi sebagai alat test rangkak tekan beton. Untuk keperluan mempercepat pematangan beton, juga dilengkapi dengan tambahan berupa cetakan benda uji dengan ukuran tertentu, alat pemanas untuk menaikkan suhu beton di dalam selinder, menggunakan pemanas listrik 1500 watt, alat ini diletakkan melingkupi cetakan silinder beton dan diberi aliran listrik dengan bantuan pengontro...

Jurnal Aplikasi Teknik Sipil, 2021

Journal of Civil Engineering, 2019

This paper presents nonlinear finite element analysis of eccentrically loaded circular Reinforced... more This paper presents nonlinear finite element analysis of eccentrically loaded circular Reinforced Concrete (RC) column confined with Carbon Fiber Reinforced Polymer (CFRP) wraps. The concrete constitutive model uses a plasticityfracture model which is restraint sensitive, utilize a non-constant plastic dilation rate, and is able to simulate the plastic volumetric compaction of concrete core under high confining pressure. For validation of the models, two available specimens from the literature are used in the validations. Excellent agreement between the numerical models and the available test results are obtained in this study. A detailed investigation on the confinement effectiveness of both external and internal confining devices are presented and discussed. This discussion of the confinement effectiveness is important to be included in the design formula.

IOP Conference Series: Earth and Environmental Science, 2020

For concrete planners and salt farmers know the distribution of sulfate in sea water becomes very... more For concrete planners and salt farmers know the distribution of sulfate in sea water becomes very important as a basis for the manufacture of concrete and as a planning analysis of salt-making. Based on this need to be done mapping the distribution of sulfate concentrations in surface sea water. In addition to the way the analysis in the laboratory, suspected sulfate can be done using an estimation algorithm as a remote sensing technique that results are presented in the form of geographic information systems. With remote sensing techniques will be obtained regional information sulfate at the sea surface since using Landsat 8 satellite recording results.The mapping of sulfate in the straits of Madura Island with Landsat 8 OLI imagery on July 26, 2018, obtained the minimal value was 2078.89 and the maximal value 2429.89.The highest sulfate concentration is in the Ujung-Kamal port area.When using SNI 2847: 2013 / ACI 318M-11 sulfate exposure in the Madura Strait includes a class of S2...

IPTEK Journal of Proceedings Series, 2017

Although the utilization of high-strength concrete and high-strength steel can reduced column dim... more Although the utilization of high-strength concrete and high-strength steel can reduced column dimension at high-rise building, the column aspect ratio remain low. These column were tended to dominate by shear failure than flexure failure. The research discusses the numerical analysis of shear critical of Highstrength reinforced concrete columns. The Uniaxial Shear Flexure Method (USFM) was used to observe this behavior and examined on the test result. This study showed that USFM method provided conservative prediction. Some modification was proposed in order to improve this method when estimate the shear behaviour of high-strength reinforced concrete column.

IPTEK Journal of Proceedings Series, 2017

This research discusses the role of transverse reinforcement as seismic reinforced concrete colum... more This research discusses the role of transverse reinforcement as seismic reinforced concrete columns confinement. The latest confinement design addressed for columns remains standing under certain level of axial compression and displacement demands. However, this purpose did not consider shear effect. An approach formulation to determine the amount of confinement for reinforcement concrete that account effect of shear is provided. This method is based on combined effects of axial and shear stress that found in coulomb failure criterion. The proposed formulation are tested in 163 column test result data base and compared with several building codes. The result showed that the formulation can reduce amount of confinement safely for most columns.

E3S Web of Conferences, 2020

During an earthquake, Reinforced Concrete (RC) building structures should behave in a ductile man... more During an earthquake, Reinforced Concrete (RC) building structures should behave in a ductile manner to prevent the structures from collapse. Therefore, the column element should have sufficient ductility to sustain an axial load at the post-peak region. Ductility of the RC column can be sufficiently provided by confinement to the RC column core. Therefore, in this paper, ductility of square RC columns made of NSC and HSSCR are analyzed using three-dimensional nonlinear finite element analysis (3D-NLFEA) with various ties configurations. In total, 12 specimens for each transverse steel rebar configuration were examined. The measurement used for ductility comparisons is the I10 index (AS 3600-2018) which is compared with the concept of ductility available in the literature (for example ACI 318-14). The study found that the computed minimum transverse steel rebar diameter based on ACI 318-14 showed larger diameter than the AS 3600:2018. From the 3DNLFEA analysis found that using a con...

E3S Web of Conferences, 2020

The use of steel fiber in concrete material can improves both the strength and the ductility of c... more The use of steel fiber in concrete material can improves both the strength and the ductility of concrete. The fibers can postpone or mitigate the concrete cover spalling under severe loading conditions such as during an earthquake. In this paper, the behavior of Steel Fiber Reinforced Concrete (SFRC) under compression is modeled using the Attard and Setunge’s stress-strain model. The parameter identification consisted of the elastic modulus (Ec), the peak strength (/cc), the residual strength (fes), and the peak strain of concrete under compression (ecc). From the investigation, it is found that the models proposed for active confined concrete can be applied for steel fiber reinforced concrete. It was also shown that the axial strain at peak stress increases as the fiber volumetric ratio and fiber aspect ratio increased. A simple formula to predict the approximate value of confining pressure to account for the steel fiber presence is proposed. The verification of the proposed model ...

Composite Structures, 2018

Strengthening reinforced concrete (RC) columns with external confining devices such as FRP wraps ... more Strengthening reinforced concrete (RC) columns with external confining devices such as FRP wraps or steel tube is widely used in construction. By using external confining devices, both the strength and ductility of RC columns are significantly improved. However, numerical modelling to predict the capacity of strengthened RC columns is limited and often oversimplified. One of the biggest challenges in numerical modelling is to deal with unequal dilation between the concrete inner core (enclosed by both transverse steel and FRP wraps) and the concrete outer core (between the transverse steel and FRP wraps). Inaccurate modelling on the concrete dilatant behavior can lead to incorrect strength prediction. Sophisticated constitutive models which are able to model concrete dilation and robust modelling techniques are required. In this paper, three-dimensional non-linear finite element analysis (3D-NLFEA) of circular RC columns confined with conventional steel stirrups and FRP wraps is presented. In the FEA, the initial stiffness method with Process Modification (acceleration technique) is used to solve the equilibrium forces in the global solution. The constitutive model is based on the plasticity formulation proposed by the authors, which can capture the effective lateral modulus   L E of the confining devices. This lateral modulus is obtained by observing the principal incremental stresses and strains at each element gauss point. It 2 was found that, the lateral modulus is greatly affected by the boundary condition, dilatant behaviour of the constitutive model and the Poisson's ratio of the external confining device. To validate the performance of the proposed model, several comparisons of the proposed model, using 3D-NLFEA, with experimental results is presented. The comparisons show that the predicted response using 3D-NLFEA and the experimental results of RC columns confined with FRP are in a good agreement.

IPTEK Journal of Proceedings Series, 2017

This paper presents a study of Rapid Visual Screening (RVS) using FEMA 154 and applied in Indones... more This paper presents a study of Rapid Visual Screening (RVS) using FEMA 154 and applied in Indonesia based on SNI 1726. RVS is a method to asses potential earthquake hazard of a building based on visual observation ("sidewalk survey") of the exterior and interior building if possible, and a Data Collection Form. This study is intended to see how important the RVS of the FEMA 154 can be implemented in Indonesia with a case study at Yogyakarta. The buildings that reviewed were assumed to have the same parameters as mention in FEMA 154 and compatible with SNI 1726 (Indonesian earthquake map). The results from field survey were compared to the numerical analysis. From the case study, it was found that the administration building of ATK Academy, the dormitory building of Ministry of Internal Affairs, the office building of Department of Agriculture, and the educational building of Health Polytechnics have a score more than 2, and the buildings are also declared safe according to SNI 1726.

Liniear Programming Untuk Optimasi Keuntungan Usaha Tani Daerah Irigasi Blega Madura, Dec 23, 2008

Kebutuhan air Daerah Irigasi Blega dipasok oleh waduk Blega. Daerah irigasi ini mempunyai luas 12... more Kebutuhan air Daerah Irigasi Blega dipasok oleh waduk Blega. Daerah irigasi ini mempunyai luas 1240.4 Ha, yang terletak di kabupaten Bangkalan, Madura, Jawa Timur. Seiring dengan berkembangnya wilayah Madura, waduk Blega merupakan salah satu dari target pemerintah sebagai sarana untuk memperluas jaringan irigasi teknis. Pada daerah studi sebagian besar lahanya masih sawah tadah hujan. Sehingga dengan dibangunya waduk ini akan dapat meningkatkan pendapatan petani dan memperbaiki sistem jaringan irigasi. Dengan kebutuhan air irigasi yang berbeda sepanjang tahun, yaitu tinggi pada musim kemarau dan kecil pada musim penghujan, Maka perlu dilakukan optimasi untuk mengatur air yang tersedia pada waduk, agar dapat dimanfaatkan semaksimal mungkin untuk irigasi dan mendapatkan keuntungan yang maksimum pada pola tanamnya. Optimasi yang akan dilakukan pada daerah studi menggunakan liniear programming dengan program bantu QM for Window 2. Liniear programming ini mempunyai keunggulan dibandingkan dengan cara konvensional. Metode ini menghapus proses coba-coba (trial and error) pada perubahan-perubahan desain dan resimulasi perubahan desain, merubah parameter-parameter desain secara otomatis, dan mempunyai penampilan yang matematis yang dapat mengambarkan responnya pada masukan-masukan sistem berbagai parameter desain. volume andalan yang ada dan kebutuhan air untuk masing-masing pola tanam yang direncanakann sebagai fungsi tujuan yang digunakan sebagai input pengoperasian program liniearnya. Dan fungsi tujuannya adalah keuntungan usaha tani. Output dari analisa ini adalah luas lahan sawah yang bisa ditanami untuk tiap-tiap jenis tanaman dan keuntungan maksimum hasil usaha tani yang diperoleh. Dari beberapa pola tanam yang direncanakan, dan awal musim tanam yang berbeda-beda. Diperoleh pola tanam yang paling menguntungkan yaitu padi-polowijo-polowijo dengan awal tanam November dekade I. Keuntungan yang diperoleh selama satu tahun masa tanam yaitu Rp 9,100,683,000.00 dengan intensitas tanaman sebesar 300%..

Penentuan lendutan (defleksi) struktur pelat menggunakan teori Kirchhoff dan Mindlin merupakan ka... more Penentuan lendutan (defleksi) struktur pelat menggunakan teori Kirchhoff dan Mindlin merupakan kajian utama tesis. Teori Kirchhoffmenetapkan tiga persamaan regangan, sedangkan path teori Mindlin lima rumusan persamaan regangan termasuk regangan geser transversal. Solusi dari kedua teori ini diproses dengan metoda elemen hingga, yang mana untuk meraldt matriks kekakuan elemen digunakan cara energi potensial minimum. Kajian analisis dibatasi dalam sistem energi konservatif, berlakunya kondisi elastik sempurna tanpa pengaruh temperatur. Digunakan program komputer dengan bahasa C++ untuk mendapatkan hasil analisis. Verifikasi hasil dengan program SAP 2000, menunjukkan tingkat akurat yang lebih baik dari teori Mindlin untuk mesh elemen setara.

Beton Stahlbetonbau, 2005