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"Water permeability of plain and fiber reinforced concrete was measured with and without and applied compressive stress. For the measurement of permeability under stress , a novel test technique was developed, in this technique , two hollow core concrete cylinders were simultaneously tested -one with stress and the other without using indentical flow conditions. A special design of the permeability cell eliminates leakage and allows the specimen to achieve conditions of flow equilibrium early in the test. For the stressed specimens , two levels of the applied stress , 0.3 Fu and 0.5 fu where fu is the ultimate strength of concrete in compression were investigated. A collated cellulose fiber at volume fractions of 0.1, 0.3 and 0.5% was used. Results indicated that in the unstressed state, fiber reinforcement reduces the permeability of concrete. For the stressed concrete on the other hand, and interesting phenomenon was observed. Initially as the applied stress was increased , a reduction in the permeability for both plain and fiber reinforced concrete was observed. This reduction, however , occurred only to a certain threshold value of stress . Beyond this threshold, a rapid increase in the permeability occurred for plain concrete. For fiber reinforced concrete as well, an increase in the permeability was noticed beyond the threshold value of stress, but the permeability still remained below the unstressed level."

"Tugas akhir ini membahas tentang analisa multiatribut dari data seismik atribut dan data sumur. Sepuluh buah sumur digunakan pada penelitian ini. Kesepuluh sumur ini dipilih karena memiliki data sumur yang lengkap dan memiliki korelasi paling baik dengan data seismik. Wavelet yang digunakan adalah wavelet statistik yang merupakan hasil ekstrak dari data sintetik. Dalam proses inversi, horison yang digunakan adalah horison top, base A, dan bot D. Model inisial dibuat dengan menggunakan kontrol sepuluh buah sumur dan tiga horizon tersebut. Dilakukan tiga jenis inversi yang diterapkan pada model inisial yaitu Inversi Bandlimited, Inversi Modelbased ?Constrained? dan LP-Sparse Spike. Volum hasil inversi itu kemudian dijadikan eksternal atribut dalam pembuatan volum pseudo permeabilitas hasil analisa atribut. Jumlah atribut yang digunakan di tentukan oleh proses step wise regression. Hasil yang diperoleh menunjukkan bahwa metoda multiatribut dapat menghasilkan prediksi distribusi permeabilitas.

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This study will discuss about multiattribute analysis from seismic attribute and log properties. Ten wells are used in this study. These wells are chosen because they have complete well data and have a good correlation with seismic at well-seismic tie process. The best wavelet that is used is extracted wavelet from statistic. In inversion process, horizon top, base A, bot D is used. Initial model is made with control of those ten wells and three horizon. Three inversion type are applied to the initial model, i.e. Bandlimited inversion, Modelbased ?Constrained? and LPSparse Spike. The inverted volume is than used as input of attribute process to produce pseudo permeability volume. The number of attributes which is used in the process, in relegation step wise regression process. Multiattribute result give distribution of permeability prediction."

"Skripsi ini berisi studi secara teoritis dan eksperimen tentang perhitungan permit-tivitas listrik dan permeabilitas magnet suatu material. Metode yang digunakan adalah metode yang diusulkan Nicolson,Ross dan Weir (NRW) untuk menghitung permittivitas dan permeabilitas dari parameter hamburan. Untuk mendapatkan parameter parameter hamburan S11,S12,S21, dan S22, kami menggunakan Vector Network Analyzer (VNA) sebagai alat ukur. Kami menerapkan metode NRW untuk memproses 2 jenis data dari tefon, yakni data yang didapat dari publikasi paper dan data yang didapat dari pengukuran secara langsung di LIPI, Bandung. Selain itu, kami juga melakukan perhitungan untuk besi (Fe) dari data yang didapat dari pengukuran secara langsung. Perbandingan hasil untuk teflon yang didapat dari paper lain dengan referensi menunjukkan kesesuaian hasil yang amat baik. Akan tetapi, penggunaan metode NRW untuk mengolah data pengukuran hasil belum memberikan hasil yang memuaskan. Kami menduga hal tersebut terjadi karena kesalahan sistematik yang terjadi pada eksperimen.

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This bachelor thesis comprehends a theoritical and experimental study on permitti-vity and permeability of microwave absorbing materials. The methods used in this study is the one proposed by Nicholson, Ross, and Weir (NRW) to compute the permittivity and permeability from the scattering parameters. To obtain the scattering

parameters S11, S12, S21 and S22 , we use a Vector Network Analyzer (VNA) as the experimental tool. We apply the NRW method to process two sets of data of teflon, one obtained from a published article and another one obtained from our own mea-surements in LIPI, Bandung. In addition, we also process the calculations for iron

(Fe) from data obtained from our own measurement. Comparing our calculation results for teflon with that shown in the referenced article, it looks that they agree pretty well. However, our implementation of NRW method to the data obtained from our own measurements does not yet give us good results. We speculate that these may be due to some systematic errors occuring in the experiments."

"Pemanfaatan bahan ramah lingkungan dalam stabilisasi tanah telah berkembang dalam satu dekade terakhir. Studi terbaru menunjukkan bahwa menambahkan enzim urease dalam larutan kalsium klorida dan urea mampu meningkatkan parameter kuat geser pasir. Tujuan dari penelitian ini adalah memperkenalkan pemanfaatan tanah lempung untuk meringankan kinerja kalsit yang dihasilkan dalam campuran enzim urease dan larutan kalsium klorida-urea. Campuran ini kemudian dicampur secara manual pada campuran pasir-lempung dan diperam selama 4 minggu, dan selanjutnya diuji dengan uji direct shear dan permeabilitas setiap dua minggu pemeraman untuk menentukan perubahan nilai permeabilitas dan parameter kuat geser dari pasir yang telah distabilisasi. Selain itu, juga dilakukan pengujian durabilitas untuk melihat ketahanan lekatan antar butiran hasil biosementasi. Hasil dari pengujian menunjukkan adanya kenaikan nilai kohesi dari 0 kPa menjadi 73 kPa dan penurunan nilai permeabilitas pasir dari 2,4 x 10-4 menjadi 1,62 x 10-6 m/s, yang disebabkan oleh bioclogging dan penambahan tanah lempung.

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Utilization of environmentally friendly materials in soil stabilization has grown in the last decade. Recent studies have shown that adding urease enzyme in calcium chloride and urea solution would lower the permeability and improve the shear strength properties of sand. The purpose of this research is to introduce the usage of clay to lighten the performance of calcite produced in the mixture of urease enzyme and calcium chloride urea solution. This mixture is then mixed manually with the sand clay mixture, cured for 4 weeks, and further tested its effect with permeability test and direct shear test conducted every two weeks of curing. The test is done in order to determine the change in permeability and development of the shear strength properties of the stabilized sand. Moreover, a durability test was also conducted to test bond strength between soil particles. The results of the tests showed an increase in cohesion from 0 kPa to 73 kPa and a decrease in sand permeability from 2,4 x 10 4 to 1.62 x 10 6 m s due to bioclogging and the addition of the clay mixture."

"Analisis petrofisika untuk menghitung nilai dari properti petrofisika suatu reservoir merupakan salah satu cara yang efektif untuk menentukan jenis dan jumlah kandungan hidrokarbon pada sumur bor. Salah satu tantangan dalam menghitung properti petrofisika yaitu pada perhitungan permeabilitas. Permeabilitas merupakan salah satu properti reservoir yang penting untuk menilai kualitas dan karakteristik di dalam batuan. Nilai sesungguhnya dari permeabilitas ditampilkan dalam data core. Namun, data core kerap kali tidak tersedia pada tiap sumur. Oleh karena itu, perlu dilakukan rock typing untuk memrediksi nilai dari permeabilitas. Tujuan dari penelitian ini yaitu untuk mendapatkan nilai properti suatu reservoir dan melakukan prediksi permeabilitas menggunakan metode Winland dan Pittman. Pada penelitian ini, perhitungan properti reservoir dan klasifikasi rock type didapatkan dari pengolahan data wireline log dan data core. Hasil dari penelitian ini diperoleh nilai dari Vshale bervariasi antara 40% – 70%. Lalu, nilai porositas yang diperoleh yaitu 6.6% - 38%. Kemudian nilai saturasi air berkisar antara 14.9% - 84.5%. Selain itu, dari hasil pengelompokkan rock type diperoleh tiga jenis rock type, yaitu RT 1 (terbaik), RT 2 (baik), dan RT 3 (buruk). Pengelompokkan dilakukan berdsarkan nilai dari porositas dan permeabilitas. Sumur X-02 digunakan sebagai acuan untuk menentukan metode terbaik pada penelitian ini. Setelah dilakukan propagasi menggunakan metode MRGC serta prediksi permeabilitas menggunakan KNN, dapat disimpulkan bahwa metode Pittman merupakan metode yang terbaik untuk digunakan pada penelitian ini.

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Petrophysical analysis to calculate the value of the petrophysical properties of a reservoir is an effective way to determine the type and amount of hydrocarbon content in a wellbore. One of the challenges in calculating petrophysical properties is permeability calculations. Permeability is one of the important reservoir properties to assess the quality and characteristics of the rock. The actual value of permeability is displayed in the core data. However, core data is often not available for every well. Therefore, it is necessary to do rock typing to predict the value of permeability. The purpose of this study is to obtain the property value of a reservoir and predict permeability using the Winland and Pittman methods. In this study, reservoir property calculations and rock type classification were obtained from wireline log and core data processing. The results of this study obtained the value of Vshale varying between 40% - 70%. Then, the porosity value obtained is 6.6% - 38%. Then the water saturation value ranges from 14.9% - 84.5%. In addition, from the results of grouping rock types, three types of rock types were obtained, namely RT 1 (the best), RT 2 (good), and RT 3 (bad). Grouping is done based on the value of porosity and permeability. X-02 well is used as a reference to determine the best method in this study. After propagation using the MRGC method and permeability prediction using KNN, it can be concluded that the Pittman method is the best method to use in this study."

"An introductory book presenting the theories, ACI Code requirements and design of reinforced concrete beams, slabs, columns, footings, retaining walls, bearing walls, prestressed concrete sections, and framework in a clear and understandable manner."

"An introductory book presenting the theories, ACI Code requirements and design of reinforced concrete beams, slabs, columns, footings, retaining walls, bearing walls, prestressed concrete sections, and framework in a clear and understandable manner."

"The maturity is a nondesctructive testing"

"ABSTRACTThe definition, purposes and applications of Damage Mechanics, which is relatively newly developed, is introduced and reviewed. Initially and mostly, Damage Mechanics relates to metal materials. The appearance of micro cracks due to the application of external load and their propagations cause damage to the material. This paper discusses and reviews Damage Mechanics when applied to concrete. A mathematical model of concrete subjected to tension using Continuum Damage Mechanics Theory proposed by Jean Lemaitre and Jacky Mazars in. 1982 is presented. This initial model, which is called Scalar Damage Model, even relatively simple in the formulation but gives quite good result to model the concrete in tension. This can be seen from the comparison between the numerical and experimental results done by them at laboratory in Cachan, France. Application of the initial model to analysis of reinforced concrete beam of three-point flexion subjected to monotonic loading is presented and evaluated. By using the initial model, the damage evolution, stress evolution and flexural rigidity evolution of the observed beams can be reviewed. The possibility of the application of the initial model to analysis of reinforced concrete beam in three-point flexion subjected to cyclic loading is also reviewed."

"Dalam studi yang dilakukan oleh Alfetra Henoch Tandita di Universitas Indonesia pada tahun 2021 mengenai sambungan spun pile-pile cap dengan benda uji berupa spun pile dengan beton pengisi, diperoleh hasil berupa parameter-parameter sambungan, seperti daktilitas, momen rotasi, dan lain-lain. Pada studi lanjutan ini, akan ditinjau mengenai damage atau kerusakan secara khusus dan lebih mendalam, terutama mengenai parameter yang menyebabkan persebarannya pada sambungan spun pile-pile cap. Parameter-parameter yang diujikan untuk mengetahui hubungannya dengan damage yang muncul antara lain parameter tulangan spiral, tulangan longitudinal, dan beban aksial. Dalam pengujian numerik menggunakan software ABAQUS ini, diperoleh hasil bahwa parameter aksial merupakan parameter yang paling konsisten dan signifikan dalam menambah kekakuan spun pile, sehingga damage yang ada lebih tersebar dan tidak terlokalisasi. Parameter berikutnya yang cukup konsisten adalah tulangan spiral, dan yang terakhir adalah parameter tulangan longitudinal. Parameter tulangan longitudinal dinilai tidak konsisten karena perkembangannya tidak mengikuti suatu pola tertentu, yang diduga diakibatkan kapasitas tulangan-tulangan longitudinal parameternya yang telah mendekati titik fracture.

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In a study conducted by Alfetra Henoch Tandita at the University of Indonesia in 2021, regarding the connection between spun pile-pile cap and a test object consisting of a spun pile with filled concrete, results were obtained in the form of connection parameters such as ductility, rotational moment, and others. In this further study, the focus will be on examining the specific and deeper aspects of damage, particularly regarding the parameters that cause its distribution in the spun pile-pile cap connection. The parameters tested to understand their relationship with the emerging damage include spiral reinforcement, longitudinal reinforcement, and axial load. Through numerical testing using the ABAQUS software, it was found that the axial parameter is the most consistent and significant parameter in increasing the stiffness of the spun pile, resulting in more widespread and non-localized damage. The next parameter that showed sufficient consistency is the spiral reinforcement, and the last one is the longitudinal reinforcement parameter. The longitudinal reinforcement parameter is considered inconsistent because its development does not follow a specific pattern, which is suspected to be caused by the longitudinal reinforcement's capacity approaching the point of fracture."