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"Aplikasi praktis dari solusi nanopartikel telah dibatasi karena memiliki dampak yang buruk pada degradasi mekanik. Tujuan penelitian ini adalah untuk menguji karakteristik aliran nanofluida. Hasil percobaan berupa kurva aliran dari nanofluida pada sebuah pipa kapiler yang mempunyai variabel tekanan. Yang diameter pipa tersebut adalah sebesar 3 mm. Tegangan geser dan regangan geser dihitung dengan mengukur pressure drop dan laju aliran volumetrik. Pengukuran pressure drop dilakukan untuk Al2O3 dan TiO2 (konsentrasi 1%, 3% dan 5%) dengan menggunakan pressure tranducer. Power Law Index berada pada kisaran harga 0,95 - 1,0. Koefisien gesekan nanofluida yang telah didapat, dibandingkan dengan data dari air murni yang digambarkan dengan persamaan Blasius.

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The practical application of the nanoparticle of solutions has been limited because it has an adverse effect on mechanical degradation. The aim of this study is to examine characteristics of flow properties of nanofluid. Experiments are carried out the measurement of the flow curve of the nanofluid by a capillary pipe applying variable pressure driven flow. It is 3 mm in the diameter of the capillary. The shear stress and the shear strain are calculated by measuring the pressure drop and the volumetric flow rate, respectively.

Measurements of pressure drop are carried out for Al2O3 and TiO2 at 1%, 3%, 5% particle volume with pure water by a pressure transducer. The power law exponent are about 0.95 - 1.0. The friction coefficient of nanofluid in a capillary pipe are fit with pure water data as Blasius's equation."

"Pada proses pengerjaan panas logam (hot forming) perilaku mekanik material dipengaruhi oleh temperatur kecepatan proses serta kondisi kontak permukaan. Untuk mendapatkan gaya deformasi pengerjaan panas perlu diketahui rheologi bahan kondisi panas. Dalam penelitian ini dipelajari perilaku rheologi kuningan C26800 yang digunakan sebagai bahan katup tabung gas yang mana dalam pembuatannya adalah dengan tempa panas. Dari hasil penelitian didapat bahwa persamaan konstitutif kuningan dapat digambarkan dengan persamaan..."

"[ABSTRAKPenelitian susut dan rangkak di daerah tropis lembab ini dilakukan pada beton berkinerja tinggi fc’ 60 MPa dengan campuran tanpa abu terbang (TAT) dan dengan abu terbang (DAT). Spesimen susut berukuran 150х150х600 mm3 (3 buah) dan spesimen rangkak 200х600х2700 mm3 (1 buah). Pemberian beban dilakukan dengan cara pratekan sebesar 0.3 fc’ pada umur 15 hari, tulangan sebatas emberian beban tersebut. Ruang dikondisikan pada temperature 28±3OC dan kelembaban 72±5%.Model dibuat berdasar pengamatan 800 hari dan 1000 hari. Data diolah dengan metode outlying ASTM E178-02 untuk nilai ekstrim dengan tingkat signifikansi 5%.Tujuan penelitian ini adalah menghasilkan model rheologi susut dan rangkak beton berkinerja tinggi di daerah tropis lembab.Model rheologi susut sampai jangka waktu 1000 hari adalah (H|N)-(H|N), sedangkan untuk rangkak (H|N)- (StV|N). Faktor koreksi susut untuk rasio air terhadap semen (w/cm) 0.26, 0.30, 0.34, dan 0.38 dalam jangka pendek (7-15 hari) berturut-turut adalah 1, 1.1, 2.1 dan 2.3, serta untuk jangka panjang 1, 1.13, 1.54 dan 1.65. Faktor koreksi jumlah semen sama dengan faktor koreksi ACI 209R Tropis lembab menyebabkan suhu maximum 24 jam pertama untuk skala penuh dapatmencapai 2 kali suhu maximum di daerah non tropis lembab. Pencapaian suhu maximum tersebut setengah waktu pencapaian suhu maximum di daerah non tropis.Laju regangan susut di daerah tropis lembab pada jangka pendek TAT adalah 1.1 dan jangka panjang 4.1 kali laju regangan ACI 209R dan bila dengan abu terbang 1.6 dan 2.4. Laju rangkak kedua campuran terhadap ACI adalah 0.8 untuk jangka pendek dan 1.8 untuk jangka panjang. Regangan susut jangka panjang terhadap ACI 209 untukTAT 1.7 dan DAT 1.4; sedang rangkak 1.3 dan 1.;

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ABSTRACTThe research of shrinkage and creep in humid tropical weather area was done in highperformance concrete HPC fc of 6The research of shrinkage and creep in humid tropical weather area was done in highperformance concrete (HPC) fc’ of 60 MPa mixed with composition without fly ash called TAT and within fly ash called DAT. Three shrinkage specimens are 150х150х600 mm3 and one creep specimen is 200х600х2700 mm3. Loading was applied by prestressing of 0.3 fc’in 15th day, the reinforcement was limited by that prestressing. Room was set in 28 ± 3oC temperature and 72 ± 5% humidity. Rheological models were created based on 800 days and 1000 daysobservation. Datas were processed by using ASTM E178-02 outlying methode for extreme value with 5% significant level.The objective of this research is to create rheological models of shrinkage and creep of high performance concrete in humid tropical weather.Shrinkage rheological model until the age of 1000 days is (H|N)-(H|N), while for creep is (H|N)- (StV|N). Shrinkage correction factors for water ratio to cement (w/cm) of 0.26, 0.30, 0.34, and 0.38 (7-15 days) are 1, 1.1, 2.1 and 2.3 respectively, and for long term are 1, 1.13, 1.54 dan 1.65. Correction factors of cement amount was similar with correction factor of ACI 209R.Humid tropical area caused maximum temperature in first 24 hours could reach 2 times of maximum temperature in non humid tropical area (full scale). The maximum temperature achievement was much faster, that was a half of maximum temperature achievement in non humid tropical area. Reffered to ACI 209 R, the rate of shrinkagein humid tropical area in short term is 1.1 and for long term is 4.1 times rate ACI 209R for TAT, 1.6 and 2.4 for DAT. Creep rate of the both mixture was compared with ACI 209R: 0.8 for short term and 1.8 for long term. Long term shrinkage strain of TAT and DAT was 1.7 and 1.4 times ACI 209R, while for creep was 1.3 and 1.0 MPa mixed with composition without fly ashcalled TAT and within fly ash called DAT Three shrinkage specimens are150 150 600 mm3 and one creep specimen is 200 600 2700 mm3 Loading wasapplied by prestressing of 0 3 fc in 15th day the reinforcement was limited by thatprestressing Room was set in 28 3oC temperature and 72 5 humidity Rheological models were created based on 800 days and 1000 daysobservation Datas were processed by using ASTM E178 02 outlying methode forextreme value with 5 significant level The objective of this research is to create rheological models of shrinkage and creepof high performance concrete in humid tropical weather Shrinkage rheological model until the age of 1000 days is H N H N while forcreep is H N StV N Shrinkage correction factors for water ratio to cement w cm of 0 26 0 30 0 34 and 0 38 7 15 days are 1 1 1 2 1 and 2 3 respectively and for long term are 1 1 13 1 54 dan 1 65 Correction factors of cement amount wassimilar with correction factor of ACI 209R Humid tropical area caused maximum temperature in first 24 hours could reach 2times of maximum temperature in non humid tropical area full scale The maximumtemperature achievement was much faster that was a half of maximum temperatureachievement in non humid tropical area Reffered to ACI 209 R the rate of shrinkagein humid tropical area in short term is 1 1 and for long term is 4 1 times rate ACI209R for TAT 1 6 and 2 4 for DAT Creep rate of the both mixture was comparedwith ACI 209R 0 8 for short term and 1 8 for long term Long term shrinkage strainof TAT and DAT was 1 7 and 1 4 times ACI 209R while for creep was 1 3 and 1 , The research of shrinkage and creep in humid tropical weather area was done in highperformance concrete HPC fc of 6The research of shrinkage and creep in humid tropical weather area was done in highperformance concrete (HPC) fc’ of 60 MPa mixed with composition without fly ash called TAT and within fly ash called DAT. Three shrinkage specimens are 150х150х600 mm3 and one creep specimen is 200х600х2700 mm3. Loading was applied by prestressing of 0.3 fc’in 15th day, the reinforcement was limited by that prestressing. Room was set in 28 ± 3oC temperature and 72 ± 5% humidity. Rheological models were created based on 800 days and 1000 daysobservation. Datas were processed by using ASTM E178-02 outlying methode for extreme value with 5% significant level.The objective of this research is to create rheological models of shrinkage and creep of high performance concrete in humid tropical weather.Shrinkage rheological model until the age of 1000 days is (H|N)-(H|N), while for creep is (H|N)- (StV|N). Shrinkage correction factors for water ratio to cement (w/cm) of 0.26, 0.30, 0.34, and 0.38 (7-15 days) are 1, 1.1, 2.1 and 2.3 respectively, and for long term are 1, 1.13, 1.54 dan 1.65. Correction factors of cement amount was similar with correction factor of ACI 209R.Humid tropical area caused maximum temperature in first 24 hours could reach 2 times of maximum temperature in non humid tropical area (full scale). The maximum temperature achievement was much faster, that was a half of maximum temperature achievement in non humid tropical area. Reffered to ACI 209 R, the rate of shrinkagein humid tropical area in short term is 1.1 and for long term is 4.1 times rate ACI 209R for TAT, 1.6 and 2.4 for DAT. Creep rate of the both mixture was compared with ACI 209R: 0.8 for short term and 1.8 for long term. Long term shrinkage strain of TAT and DAT was 1.7 and 1.4 times ACI 209R, while for creep was 1.3 and 1.0 MPa mixed with composition without fly ashcalled TAT and within fly ash called DAT Three shrinkage specimens are150 150 600 mm3 and one creep specimen is 200 600 2700 mm3 Loading wasapplied by prestressing of 0 3 fc in 15th day the reinforcement was limited by thatprestressing Room was set in 28 3oC temperature and 72 5 humidity Rheological models were created based on 800 days and 1000 daysobservation Datas were processed by using ASTM E178 02 outlying methode forextreme value with 5 significant level The objective of this research is to create rheological models of shrinkage and creepof high performance concrete in humid tropical weather Shrinkage rheological model until the age of 1000 days is H N H N while forcreep is H N StV N Shrinkage correction factors for water ratio to cement w cm of 0 26 0 30 0 34 and 0 38 7 15 days are 1 1 1 2 1 and 2 3 respectively and for long term are 1 1 13 1 54 dan 1 65 Correction factors of cement amount wassimilar with correction factor of ACI 209R Humid tropical area caused maximum temperature in first 24 hours could reach 2times of maximum temperature in non humid tropical area full scale The maximumtemperature achievement was much faster that was a half of maximum temperatureachievement in non humid tropical area Reffered to ACI 209 R the rate of shrinkagein humid tropical area in short term is 1 1 and for long term is 4 1 times rate ACI209R for TAT 1 6 and 2 4 for DAT Creep rate of the both mixture was comparedwith ACI 209R 0 8 for short term and 1 8 for long term Long term shrinkage strainof TAT and DAT was 1 7 and 1 4 times ACI 209R while for creep was 1 3 and 1 ]"

"Ice slurry merupakan salah satu terobosan inovatif terkini dalam penyimpan energi dingin. Pada aspek reologi, permodelan fluida dari aliran ice slurry memiliki karakteristik yang belum banyak di tinjau dan di teliti. Pada studi ini, tujuan dari penelitian ini adalah melakukan studi eksperimen reologi dan visualisasi dari aliran ice slurry pada pipa horizontal. Konsentrasi aditif di variasikan dari 8% - 25% dan fraksi masa es di variasikan dari 4% -29%. Pipa horizontal, sebagai uji reologi, memiliki panjang 1.2 m dengan diameter 25.4 mm. Pengaruh dari kecepatan aliran, pressure drop, temperatur, konsentrasi aditif, dan fraksi massa terhadap reologi ice slurry di ungkap pada penelitian ini. Pengujian reologi ini mencakup aliran laminar hingga transisi.Hasil penelitian reologi mengungkapkan bahwa ice slurry memiliki karakteristik aliran Newtonian dan non-Newtonian tergantung pada fraksi massa yang di hasilkan. Sebagai tambahan, diagram visualisasi aliran dan transport karakteristik dari ice slurry di ajukan pada studi ini. Selanjutnya, Perbandingan data eksperimen dengan berbagai model fluida yang digunakan untuk memprediksi pressure drop ice slurry menunjukkan prediktabilitas yang rendah (yaitu, deviasi rata-rata 30% hingga 86%). Oleh karena itu, model fluida baru dikembangkan dengan menggunakan metode regresi non-linear. Model fluida dari pressure drop ini di definisikan sebagai fungsi dari konsentrasi aditif dan fraksi massa. Model yang dihasilkan berhasil memprediksi data pressure drop dengan deviasi rata-rata 15%. Dengan demikian, penelitian ini dapat memberikan pemahaman mendalam tentang karakteristik reologi dari aliran ice slurry dan berkontribusi pada pengembangan lebih lanjut dari teknologi pendinginan alternatif ini

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Ice slurry is one of the innovative breakthroughs in cold energy storage. In the rheological aspect, ice slurry flow has characteristics that have not been reviewed and thoroughly studied. In this study, the aim of this study was to conduct rheological studies and visualization of the ice slurry flow in a horizontal pipe. The concentration of additives was varied from 8% - 25% and the ice mass fraction was varied from 4% -29%. The horizontal pipe, as a rheological test, has a length of 1.2 m and an inner diameter of 25.4 mm. The effect of flow velocity, pressure drop, temperature, additive concentration, and mass fraction on ice slurry rheology was revealed in this study. The rheological test was conducted from laminar to transition flow.

The results of rheological research revealed that ice slurry has Newtonian and non-Newtonian flow characteristics depending on the mass fraction. In addition, visualization diagram and transport characteristics of ice slurry were proposed. A comparison of the experimental data with various existing fluid models used for ice slurry exhibited poor predictability of the pressure drop using these existing models (i.e., a mean deviation of 30%–86%). Therefore, a new fluid model was developed by using a nonlinear regression method, and defining the pressure drop as a function of aditive concentration and ice mass fraction. The resulting model successfully predicted the experimentally obtained pressure data with a mean deviation of 15%. This work thus advances the understanding of the rheological characteristics of ice slurry and will contribute to further development of this alternative cooling technology."

"Penelitian ini menampilkan model rheologi beton berkinerja tinggi (High Performance Concrete) dengan kuat tekan 60 MPa pada umur awal beton. Dua buah balok yang digunakan berukuran 150mm x 150mm x 600mm berdasarkan ASTM C78-94. Pengamatan dilakukan selama 24 jam di awal atau pada saat sebelum curing menggunakan Vibrating Wire Embedded Strain Gages.Model rheologi didekati dengan menggunakan data regangan susut rata-rata dari kedua balok tersebut, serta beberapa parameter rheologi diperoleh dengan menggunakan trial and error. Model rheologi beton berkinerja tinggi pada umur awal beton dibagi menjadi lima rheologi yang terdiri dari Solidifying Liquid - Kelvin Voigt Niken - Kelvin Voigt Niken - Kelvin Voigt Niken - Kelvin Voigt Niken.

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This study presents rheological model of high performance concrete with 60 MPa compressive strength of concrete at early age. The size of these two beams is 150 mm x 150 mm x 600 mm according to ASTM C78-94. Observations were made during 24 hours at the beginning or at the time before curing using vibrating wire embeded strain gages. Rheological models approximated using shrinkage strain data is the average of the two beams, as well as some rheological parameters obtained by using trial and error. Rheological models of high performance concrete at early age concrete is divided into five rheological model, consists of Solidifying Liquid - Kelvin Voigt Niken - Kelvin Voigt Niken - Kelvin Voigt Niken - Kelvin Voigt Niken."

"EPDM dan NR merupakan polimer yang tidak misibel dan kompatibel. Penambahan kompatibiliser maleat anhidrat diharapkan menghasilkan campuran yang kompatibel dengan sifat mekanik yang baik. Pencampuran EPDM dan NR dilakukan menggunakan alat two roll mill, dengan rasio EPDM/NR adalah: 100/0, 80/20, 70/30, 60/40, 50/50, dan 40/60 phr. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh rasio EPDM/NR terhadap sifat reologi, aging, termal dan swelling dari campuran EPDM/NR. Hasil penelitian menunjukkan penambahan NR mempengaruhi torsi maksimum, waktu scorch dan waktu vulkanisasi optimum. Penambahan EPDM memberikan sifat aging, termal dan swelling lebih baik.

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The blends of EPDM and NR are immiscible in nature and incompatible. Introducing maleic anhydride as a compatibilizer into the blends was expected to produce compatible blends with balanced mechanical properties.

The purpose of this research was to determine the effect of EPDM/NR ratio on the rheological, aging, thermal and swelling properties of the blends. The variation of EPDM/NR ratio were 100/0, 80/20, 70/30, 60/40, 50/50, and 40/60 phr. The blends were mixed using two roll mill.

The results showed that the addition of NR affects the maximum torque, scorch time, and optimum vulcanization time. In the blends, EPDM plays an important role in improving aging, swelling, thermal properties."

"Aplikasi praktis dari solusi nanopartikel telah dibatasi karena memiliki dampak yang buruk pada degradasi mekanik. Tujuan penelitian ini adalah untuk menguji karakteristik aliran nanofluida. Hasil percobaan berupa kurva aliran dari nanofluida pada sebuah pipa kapiler yang mempunyai variabel tekanan. Yang diameter pipa tersebut adalah sebesar 3 mm. Tegangan geser dan regangan geser dihitung dengan mengukur pressure drop dan laju aliran volumetrik. Pengukuran pressure drop dilakukan untuk Al2O3 dan TiO2 (konsentrasi 1%, 3% dan 5%) dengan menggunakan pressure tranducer. Power Law Index berada pada kisaran harga 0,95 ~ 1,0. Koefisien gesekan nanofluida yang telah didapat, dibandingkan dengan data dari air murni yang digambarkan dengan persamaan Blasius.

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The practical application of the nanoparticle of solutions has been limited because it has an adverse effect on mechanical degradation. The aim of this study is to examine characteristics of flow properties of nanofluid. Experiments are carried out the measurement of the flow curve of the nanofluid by a capillary pipe applying variable pressure driven flow. It is 3 mm in the diameter of the capillary. The shear stress and the shear strain are calculated by measuring the pressure drop and the volumetric flow rate, respectively. Measurements of pressure drop are carried out for Al2O3 and TiO2 at 1%, 3%, 5% particle volume with pure water by a pressure transducer. The power law exponent are about 0.95 ! 1.0. The friction coefficient of nanofluid in a capillary pipe are fit with pure water data as Blasius's equation."

"Kekentalan fluida, jenis fluida, kecepatan alir adalah komponen yang mempengaruhi pemakaian energi. Sistem aliran pada mesin atau kapal sangat kompleks dan banyak jenis fluida yang digunakan. Tujuan penelitian kami adalah mengetahui karakteristik fluida (rheological) dimana saat mengalir akan mengalami gaya penarikan dan penekanan. Jenis Viskometer yang digunakan harus sesuai dengan kekentalan fluida uji. Piezoactuator viskometer dengan pelat datar dan pelat miring dapat digunakan untuk membuat kurva aliran hubungan antara shear stress dengan shear rate. Oil, grease, crude oil, dan pasta gigi digunakan dalam percobaan kali ini. Penambahan jarak antar pelat serta kemiringan sudut menunjukkan grafik dengan jelas dimana fluida-fluida tersebut akan mengalami variasi nilai shear stress dan nilai strain rate yang diikuti pula dengan perubahan viskositas fluida.

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Fluid viscosity, fluid type, and flow rate are teh components that effect energy consumption. Flow systen on a mechine or vessel is very complex and many types of fluid used. The purpose of our experiment was to determine the characteristics of the fluid (Rheology) where the current flows will experience withdrawal style and emphasis. Type of viscometer used must be in accordance with the test fluid viscosity. Piezoactuator viscometer with flat and sloping plate can be used to make the flow curve relationship between shear stress and shear rate. Oil, grease, crude oil and toothpaste are used in our experiment this time. The addition of gap distance between two parallel plates and slope angle clearly shows where the fluids will experience variation in the value of shear stress and strain rate, and it is also followed by changes in fluid viscosity."

"Sistem aliran pada mesin atau kapal sangat kompleks dan banyak jenis fluida yang digunakan. Kekentalan fluida, jenis fluida, dan kecepatan alir adalah komponen yang mempengaruhi pemakaian energy seperti pada sistem aliran. Tujuan penelitian ini adalah untuk mengetahui karateristik fluida (rheologi) saat diberi gaya penekanan dan penarikan dengan menggunakan viskometer. Jenis Viskometer yang digunakan harus disesuaikan dengan kekentalan fluida uji. Piezoelectric viskometer dengan pelat yang yang memiliki kemiringan sudut dapat menunjukkan kurva aliran hubungan antara tegangan geser dengan penambahan kecepatan. Oil, grease, crude oil, dan pasta gigi digunakan dalam percobaan kali ini. Penambahan besar kemiringan sudut antar pelat akan diikuti dengan perubahan nilai shear stress-strain rate.

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Flow system on a machine or vessel is very complex and many types of fluid used. Fluid viscosity, fluid type and flow rate are the components that affect energy consumption such as the flow system. The purpose of this study was to determine the fluid characteristics (rheological) when given the emphasis on style and withdrawal by using a viscometer. Type Viscometer used must be adapted to test the fluid viscosity. Piezoelectric plate viscometer with a tilt angle to show the relationship between the flow curve of shear stress with the addition of speed. Oil, grease, crude oil, and toothpaste are used in the experiment this time. The addition of the tilt angle between the plates will be followed by changes in shear stress-strain rate."

"Semburan lumpur pada berbagai daerah di Indonesia telah mendapatkan perhatian sebab bertambahnya titik semburan. Bencana tersebut berdampak negatif pada kelangsungan ekosistem sekitar. Penggunaan pipa untuk mengalirkan lumpur menuju penampungan atau lahan kosong bisa dilakukan sebagai salah satu cara penanggulangan bencana, tetapi permasalahan-permasalahan dalam pengaliran slurry seperti munculnya pengendapan masih dapat terjadi. Study terkini tentang pengaliran slurry menggunakan pipa spiral menunjukkan hasil yang lebih efisien dibandingkan pipa bulat biasa. Namun penggunaan pipa spiral mampu meminimalisir pengendapan pada bagian dasar pipa, disebabkan oleh bentuk geometri pipa yang membentuk pola aliran tangential mengikuti bentuk dinding pipa. Maka dari itu paper ini bertujuan untuk mengkaji karakteristik aliran mud slurry secara reological pada pipa spiral dengan beberapa konsentrasi berat, yaitu 20 CW, 30 CW, dan 40 CW. Lalu membandingkannya dengan perubahan massa hasil pengukuran. Metode yang digunakan adalah dengan membandingkan aliran mud slurry dalam pipa spiral ber-ratio P/Do = 7.3 dan 3.1 serta sebuah pipa bulat berdiameter 40 mm. Pengambilan data dilakukan dengan memvariasikan kecepatan aliran dengan mengatur besar sudut bukaan valve dari sudut 0o hingga 90o sebanyak 20 titik. Agar didapatkan ragam nilai Pressure drop, flow rate, serta perubahan jumlah massa padatan. Selanjutnya data hasil uji diolah menggunakan dasar ilmu Rheology dan memplotnya pada grafik.

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A mud eruption in various regions in Indonesia has received attention because of the increase in burst points. The disaster had a negative impact on the sustainability of the surrounding ecosystem. The use of pipes for flowing mud into a reservoir or vacant land can be done as a method of disaster management, but problems in slurry flow such as the appearance of precipitation can still occur. Recent studies on slurry drainage using spiral pipes show more efficient results than ordinary round pipes. The use of spiral pipes can minimize deposition at the bottom of the pipe, caused by the geometry of the pipe which forms a tangential flow pattern following the shape of the pipe wall. Therefore the present study aims to examine the characteristics of reological mud slurry flow in spiral pipes with several heavy concentrations, namely 20 CW, 30 CW, and 40 CW. Then compare it with the change in mass of the measurement results. The method used is to compare the flow of mud slurry in the spiral pipe ratio P / Do = 7.3 and 3.1 and a round pipe with a diameter of 40 mm. Data retrieval is done by varying the flow speed by adjusting the valve opening angle from 0o to 90o from 20 points. In order to obtain a variety of pressure drop, flow rates, and changes in the amount of solid mass. Then the test results data are processed using the basis of Rheology and plot it on the graph."