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Analisis Dinamika Atmosfer Saat Hujan Lebat di Wilayah Pontianak Menggunakan Model WRF-ARW (Studi Kasus 22-23 Desember 2022)
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West Kalimantan has a tropical rainforest climate characterized by high rainfall intensity. On December 22–23, 2022, heavy rainfall occurred in Pontianak City with an intensity reaching 101.3 mm/day, resulting in flooding in the area. This study analyzes weather conditions and atmospheric stability during the event using the WRF-ARW model with FNL data as model input, along with GSMaP data and observations of air temperature and surface pressure for verification. Model accuracy was evaluated using dichotomous equations (Accuracy, FAR, POFD), correlation coefficient, and Mean Absolute Error (MAE). The verification results indicate that the GD scheme performed better than the KF Kessler and KF Lin schemes, with the GD scheme achieving an accuracy value of 0.74 and lower error. Analysis using the GD scheme suggests atmospheric conditions conducive to the formation of convective clouds that caused the heavy rainfall. These conditions were marked by an unstable atmosphere with a maximum temperature of 30°C before the rain, low surface pressure, high wind speeds in the waters west of Pontianak City, humidity reaching 100%, and CAPE values indicating moderate instability (2000 J/kg).
Keywords: Heavy rain, cumulus parameterization scheme, WRF-ARW
Abstrak
Kalimantan Barat memiliki iklim hutan hujan tropis yang dicirikan dengan intensitas curah hujan tinggi. Pada 22–23 Desember 2022, terjadi hujan lebat di Kota Pontianak dengan intensitas mencapai 101,3 mm/hari, yang menyebabkan banjir di kota tersebut. Studi ini menganalisis kondisi cuaca dan stabilitas atmosfer selama peristiwa tersebut menggunakan model WRF-ARW dengan data FNL sebagai input model, serta data GSMaP dan pengamatan suhu udara serta tekanan permukaan untuk verifikasi. Akurasi model dievaluasi menggunakan persamaan dikotomi (Akurasi, FAR, POFD), koefisien korelasi, dan Mean Absolute Error (MAE). Hasil verifikasi menunjukkan bahwa skema GD memiliki performa lebih baik dibandingkan skema KF Kessler dan KF Lin, dengan nilai akurasi skema GD mencapai 0,74, serta error lebih rendah. Analisis dengan skema GD mengindikasikan kondisi atmosfer yang mendukung pembentukan awan konvektif penyebab hujan lebat. Kondisi ini ditandai oleh atmosfer yang labil dengan suhu maksimum 30°C sebelum hujan, tekanan permukaan rendah, kecepatan angin yang tinggi di perairan bagian barat Kota Pontianak, kelembapan udara mencapai 100%, serta kategori CAPE menunjukkan ketidakstabilan sedang (2000 J/Kg).
Kata-kata kunci: Hujan lebat, skema parameterisasi kumulus, WRF-AR
Perilaku Pelajar dalam Keselamatan Berlalu Lintas di Kota Bandung
No full textAbstrak
Seiring meningkatnya jumlah penduduk menyebabkan bertambahnya kepemilikan kendaraan pribadi, yang kemudian menyebabkan meningkatkan kecelakaan lalu lintas di Kota Bandung. Penelitian ini dilakukan dengan tujuan mengidentifikasi perilaku pelajar remaja Kota Bandung dalam berjalan kaki dengan mengadaptasi Adolescent Road User Behaviour Questionnaire (ARBQ). Analisis faktor menggunakan metode Principal Axis Factoring (PAF) dan Confirmatory Factor Analysis (CFA) serta analisis ANOVA juga digunakan dalam penelitian ini. Hasil analisis faktor membentuk 3 kelompok faktor, yaitu Faktor 1: perilaku berjalan kaki dan menyeberang jalan, Faktor 2: perilaku tertib berlalu lintas, dan Faktor 3: perilaku bermain di jalan. Hasil analisis ANOVA menunjukkan, responden laki-laki lebih cenderung terlibat dalam perilaku menyeberang yang tidak berkeselamatan dan permainan yang membahayakan di jalan. Sedangkan untuk perilaku keselamatan lebih sering dilakukan oleh responden perempuan dan responden yang usianya lebih muda (11-12 tahun). Faktor seringnya bersama teman di jalan juga mempengaruhi responden untuk melakukan perilaku berisiko. Untuk mengurangi dan mencegah terjadinya kecelakaan lalu lintas yang melibatkan remaja di Kota Bandung, disusun rekomendasi penanganan berupa: sosialisasi kepada pengemudi dan edukasi kepada pelajar, pengembangan fasilitas persimpangan dan trotoar yang aman dan tertib serta penyediaan lapangan bermain untuk anak-anak, dan penambahan petugas pengatur lalu lintas.
Kata kunci : Perilaku berjalan kaki, pelajar, remaja, ARBQ, PAF, CFA, ANOVA
Abstract
The rapid population growth in Bandung has led to a significant increase in private vehicle ownership, contributing to a rise in traffic crashes. In response, this research aims to examine the road behavior of school students in Bandung by adapting the Adolescent Road User Behavior Questionnaire (ARBQ). The study employs Principal Axis Factoring (PAF) and Confirmatory Factor Analysis (CFA) to explore the questionnaire’s factor structure, along with ANOVA analysis to assess behavioral differences. The factor analysis identified three distinct factors: (1) pedestrian walking and crossing behavior, (2) safety behavior, and (3) playing on the road behavior. Subsequent ANOVA analysis yielded several key findings. Male respondents were more likely to engage in unsafe road-crossing behaviors and risky play on the road. Additionally, a significant correlation was found between playing on the road and other risky behaviors. Interestingly, while safe behaviors were more commonly observed among female respondents and younger students (aged 11-12), students who were frequently accompanied by friends on the road exhibited a higher tendency toward risky behavior.To reduce student-related traffic crashes, this study recommends awareness campaigns for drivers, road safety education for students, safer intersections and sidewalks, designated play areas, and increased traffic officer deployment.
Keywords : Safety, pedestians, adolescent, ARBQ, PAF, CFA, ANOVAAbstrak
Seiring meningkatnya jumlah penduduk menyebabkan bertambahnya kepemilikan kendaraan pribadi, yang kemudian menyebabkan meningkatkan kecelakaan lalu lintas di Kota Bandung. Penelitian ini dilakukan dengan tujuan mengidentifikasi perilaku pelajar remaja Kota Bandung dalam berjalan kaki dengan mengadaptasi Adolescent Road User Behaviour Questionnaire (ARBQ). Analisis faktor menggunakan metode Principal Axis Factoring (PAF) dan Confirmatory Factor Analysis (CFA) serta analisis ANOVA juga digunakan dalam penelitian ini. Hasil analisis faktor membentuk 3 kelompok faktor, yaitu Faktor 1: perilaku berjalan kaki dan menyeberang jalan, Faktor 2: perilaku tertib berlalu lintas, dan Faktor 3: perilaku bermain di jalan. Hasil analisis ANOVA menunjukkan, responden laki-laki lebih cenderung terlibat dalam perilaku menyeberang yang tidak berkeselamatan dan permainan yang membahayakan di jalan. Sedangkan untuk perilaku keselamatan lebih sering dilakukan oleh responden perempuan dan responden yang usianya lebih muda (11-12 tahun). Faktor seringnya bersama teman di jalan juga mempengaruhi responden untuk melakukan perilaku berisiko. Untuk mengurangi dan mencegah terjadinya kecelakaan lalu lintas yang melibatkan remaja di Kota Bandung, disusun rekomendasi penanganan berupa: sosialisasi kepada pengemudi dan edukasi kepada pelajar, pengembangan fasilitas persimpangan dan trotoar yang aman dan tertib serta penyediaan lapangan bermain untuk anak-anak, dan penambahan petugas pengatur lalu lintas.
Kata kunci : Perilaku berjalan kaki, pelajar, remaja, ARBQ, PAF, CFA, ANOVA
Abstract
The rapid population growth in Bandung has led to a significant increase in private vehicle ownership, contributing to a rise in traffic crashes. In response, this research aims to examine the road behavior of school students in Bandung by adapting the Adolescent Road User Behavior Questionnaire (ARBQ). The study employs Principal Axis Factoring (PAF) and Confirmatory Factor Analysis (CFA) to explore the questionnaire’s factor structure, along with ANOVA analysis to assess behavioral differences. The factor analysis identified three distinct factors: (1) pedestrian walking and crossing behavior, (2) safety behavior, and (3) playing on the road behavior. Subsequent ANOVA analysis yielded several key findings. Male respondents were more likely to engage in unsafe road-crossing behaviors and risky play on the road. Additionally, a significant correlation was found between playing on the road and other risky behaviors. Interestingly, while safe behaviors were more commonly observed among female respondents and younger students (aged 11-12), students who were frequently accompanied by friends on the road exhibited a higher tendency toward risky behavior.To reduce student-related traffic crashes, this study recommends awareness campaigns for drivers, road safety education for students, safer intersections and sidewalks, designated play areas, and increased traffic officer deployment.
Keywords : Safety, pedestians, adolescent, ARBQ, PAF, CFA, ANOV
PENGARUH VARIASI KONSENTRASI EKTRAK DAUN TEH HIJAU (Camellia sinensis (L.) Kuntze) TERHADAP MUTU FISIK SEDIAAN EYE CREAM
Get PDFPremature aging of the eye area is characterized by the appearance of wrinkles, fine lines, eye bags and dark circles due to exposure to ultraviolet (UV) light, free radicals, and decreased collagen production. Green tea leaves (Camellia sinensis (L.) Kuntze) are known to contain high antioxidants, especially catechins such as epigallocatechin gallate (EGCG), so it has the potential to be used as an anti-aging agent to slow down the skin aging process. This study aims to determine the effect of variations in green tea leaf extract concentration on the physical quality of eye cream preparations and determine the best formula. The study was conducted experimentally with four eye cream formulas, namely formula 0 (0% extract), formula 1 (0.5% extract), formula 2 (5% extract), and formula 3 (10% extract). Physical quality evaluation included organoleptic test, homogeneity, pH, viscosity, spreadability, stickiness, cream type, and centrifugation test. Data were analyzed using One-Way ANOVA test and compared with eye cream physical quality standards. The results showed significant differences (p < 0.05) in the parameters of pH, viscosity, spreadability, and stickiness between formulas. Formula 1 (0.5%) fulfilled all physical quality parameters according to the standard, including even homogeneity, pH according to the skin, optimal viscosity and spreadability, and no phase separation. It was concluded that formula 1 was the best formula.
Penuaan dini pada area sekitar mata ditandai dengan munculnya kerutan, garis halus, kantung mata dan lingkaran hitam akibat paparan sinar ultraviolet (UV), radikal bebas, dan penurunan produksi kolagen. Daun teh hijau (Camellia sinensis (L.) Kuntze) diketahui mengandung antioksidan tinggi, terutama katekin seperti epigallocatechin gallate (EGCG), sehingga berpotensi digunakan sebagai agen anti aging untuk memperlambat proses penuaan kulit. Penelitian ini bertujuan untuk mengetahui pengaruh variasi konsentrasi ekstrak daun teh hijau terhadap mutu fisik sediaan eye cream serta menentukan formula terbaik. Penelitian dilakukan secara eksperimental dengan empat formula eye cream, yaitu formula 0 (0% ekstrak), formula 1 (0,5% ekstrak), formula 2 (5% ekstrak), dan formula 3 (10% ekstrak). Evaluasi mutu fisik meliputi uji organoleptik, homogenitas, pH, viskositas, daya sebar, daya lekat, tipe krim, dan uji sentrifugasi. Data dianalisis menggunakan uji One-Way ANOVA dan dibandingkan dengan standar mutu fisik eye cream. Hasil menunjukkan adanya perbedaan signifikan (p < 0,05) pada parameter pH, viskositas, daya sebar, dan daya lekat antar formula. Formula 1 (0,5%) memenuhi seluruh parameter mutu fisik yang sesuai standar, termasuk homogenitas merata, pH sesuai kulit, viskositas dan daya sebar optimal, serta tidak terjadi pemisahan fase. Disimpulkan bahwa formula 1 merupakan formula terbaik. 
Manajemen Kenyamanan Cerdas di Ruang Kelas Menggunakan Deteksi Okupansi Berbasis SSD dan Pengendalian Lingkungan Berbasis PMV
Get PDFRoom comfort is critical for enhancing productivity, particularly in classrooms. Two key factors are temperature and lighting, governed by ASHRAE 55 for thermal comfort (PMV range of –0.5 to 0.5) and SNI 6197:2020 for classroom lighting (350 lux). This study develops an intelligent system that coordinates occupant detection with temperature and lighting control. Occupant detection was implemented using the Single Shot MultiBox Detector (SSD) with MobileNetV2, a camera as the sensor, and image processing on an NVIDIA Jetson Nano. The detected occupant coordinates were used to control lighting patterns, while temperature was measured with a DHT22 sensor and regulated through PMV-based calculations. The recommended temperature setpoints were transmitted to an air conditioner via an IR blaster controlled by an ESP8266. Experimental results show that the detection system achieved 95% accuracy, 99% precision, 95% recall, and a 97% F1-score at a threshold of 0.3. The lighting control system achieved a MAPE of 14.49%, while the temperature control system achieved a MAPE of 4.53% with an average MAE of 1.1 °C. These findings demonstrate that the proposed system effectively integrates occupant detection with automated temperature and lighting control, ensuring improved classroom comfort.Kenyamanan ruang sangat penting untuk meningkatkan produktivitas, khususnya di ruang kelas. Dua faktor utama yang memengaruhi kenyamanan adalah suhu dan pencahayaan, yang diatur oleh ASHRAE 55 untuk kenyamanan termal (rentang PMV –0,5 hingga +0,5) dan SNI 6197:2020 untuk pencahayaan kelas (350 lux). Penelitian ini mengembangkan sistem cerdas yang mengoordinasikan deteksi penghuni dengan pengendalian suhu dan pencahayaan. Deteksi penghuni diimplementasikan menggunakan algoritma Single Shot MultiBox Detector (SSD) dengan MobileNetV2, kamera sebagai sensor, dan pemrosesan citra pada NVIDIA Jetson Nano. Koordinat posisi penghuni digunakan untuk mengatur pola pencahayaan, sedangkan suhu diukur dengan sensor DHT22 dan dikendalikan melalui perhitungan berbasis PMV. Nilai suhu rekomendasi kemudian dikirim ke pendingin ruangan melalui IR blaster yang dikendalikan oleh ESP8266. Hasil eksperimen menunjukkan bahwa sistem deteksi mencapai akurasi 95%, presisi 99%, recall 95%, dan skor F1 sebesar 97% pada ambang 0,3. Sistem pencahayaan mencapai MAPE sebesar 14,49%, sedangkan sistem pengendalian suhu mencapai MAPE sebesar 4,53% dengan MAE rata-rata 1,1 °C. Temuan ini menunjukkan bahwa sistem yang diusulkan mampu mengintegrasikan deteksi penghuni dengan pengendalian suhu dan pencahayaan secara otomatis untuk meningkatkan kenyamanan kelas
Comparison of Whole Body Reaction Time Between Singles and Doubles Badminton Players Aged 14–17 Years
Get PDFWhole Body Reaction Time (WBRT) is an important biomotor component in the performance of badminton athletes, especially in responding to unexpected stimuli during matches. This study aims to compare the WBRT between male singles and doubles badminton athletes aged 14–17 years. The research used a quantitative comparative approach with purposive sampling technique. The population consisted of 60 athletes at PB Taqi Arena, West Bandung Regency. Based on the inclusion criteria, 37 athletes were selected as samples, consisting of 18 singles and 19 doubles athletes. Data collection was conducted on May 3–4, 2025. Measurements included anthropometry (Omron Karada Scan HBF-375), height (Stature Meter OneMed HT701), and WBRT (Whole Body Reaction Measuring Equipment Takei TKK-5408). Shapiro–Wilk normality test results indicated normal distribution in both groups (p > 0.05). The average WBRT for singles athletes was 0.286 ± 0.024 seconds, while for doubles athletes it was 0.260 ± 0.021 seconds. The independent samples t-test showed a significant difference between the two groups (p = 0.002). These findings indicate that doubles athletes have better whole body reaction speed compared to singles athletes. This difference is likely influenced by tactical demands and playing patterns in doubles, which require quick responses to stimuli from both opponents and partners. These results can serve as a basis for designing specific training programs based on match type to optimally improve athletes' reaction performance.
Keywords: badminton, reaction time, whole body reaction, singles and doubles events
Enhancing Security of Databases through Anomaly Detection in Structured Workloads
Get PDFIn today’s world, the protection of databases in any global organization has become paramount due to the rapid growth of data and the new generations of cyber threats. This highlights the need for more enhanced security precautions to secure these databases containing sensitive information. One of the most advanced ways of enhancing database security is using an anomaly detection system, especially for structured workloads. Structured workloads typically exhibit predictable patterns of data access and usage, making them susceptible to displaying anomalies that may indicate unauthorized access, data manipulation, or other security breaches. Anomaly detection methods can identify patterns that are unusual, an indication of malicious activity, or a data security breach. The present research utilized the Isolation Forest algorithm to detect outliers in high-dimensional data sets. The main contribution and novelty of this research lies in leveraging the Isolation Forest algorithm for structured database workloads to proactively identify and mitigate potential security threats. Our study showed that the proposed model, with an accuracy of 85%, outperformed various state-of-the-art methods. Furthermore, anomaly detection systems powered by advanced algorithms and machine learning enable real-time database activities analysis, addressing challenges like preprocessing, model training and scalability
AUGMENTED REALITY CHILDREN STORYBOOK TIMUN MAS MEMBENTUK PERSEPSI VISUAL ANAK USIA DINI
Get PDFTechnology-based visual literacy reading activities are an implementation of the smart education concept that is starting to be popularly introduced to the digital native generation. The strategy to combine the power of visual-based learning media and virtual reality technology is a new innovation that seeks to present a more interesting and enjoyable reading experience for early childhood. The research aims to examine how the Augmented Reality Children Storybook (ARCS) Timun Mas media can shape early childhood cognitive-visual responses. The research was conducted using a qualitative case study method on children aged 4-6 years at Darrunajwa Kindergarten, Jombang District, East Java. The data collection techniques chosen to obtain in-depth information were observation, interviews, literature study, and documentation. The results showed that the Augmented Reality-based Timun Mas storybook media can form five indicators of children's visual-cognitive abilities including visual sensory, visual attantion, visual memory, visual spatial relation, and visual sequention memory. The visual response will then form a better visual perception of children towards the forms of visual elements, storylines to moral messages contained in the ARCS Timun Mas.Kegiatan membaca literasi visual berbasis teknologi merupakan implementasi dari konsep smart education yang mulai populer diperkenalkan kepada generasi digital native. Strategi untuk menggabungkan kekuatan media pembelajaran berbasis visual dan teknologi virtual reality merupakan inovasi baru yang berusaha menghadirkan pengalaman membaca yang lebih menarik dan menyenangkan untuk anak usia dini. Penelitian bertujuan untuk meneliti bagaimana media Augmented Reality Children Storybook (ARCS) Timun Mas dapat membentuk respon kognitif-visual anak usia dini. Penelitian dilakukan dengan metode kualitatif studi kasus pada pada anak-anak usia 4-6 tahun di TK Darrunajwa Kecamatan Jombang, Jawa Timur. Teknik pengumpulan data yang dipilih untuk mendapatkan informasi secara mendalam adalah observasi, wawancara, studi literatur, dan dokumentasi. Hasil penelitian menunjukkan bahwa media Buku cerita Timun Mas berbasis Augmented Realitydapat membentuk lima indikator kemampuan kognitif-visual anak diantaranya visual sensory, visual attantion, visual memory, visual spatial relation, dan visual sequention memory. Respon visual tersebut selanjutnya akan membentuk persepsi visual anak yang lebih baik terhadap bentuk-bentuk elemen visual, alur cerita hingga pesan moral yang terkandung pada media ARCS Timun Mas
Lighting for the Elderly in the Interior of Santa Maria Fatima Church, Magelang
Get PDFThe church is a place for religious communities to worship. Architecture within the church can be used to create spiritual experiences and strengthen religious identity. One of the elements capable of facilitating spiritual experiences for the congregation is the element of enlightenment. In addition to serving to arouse a spiritual atmosphere in the church, lighting also serves as a symbol of religion and illumination in the space. In the case study of the Church of St. Mary Fatima Magelang, the church is undergoing a reconstruction process in which the old church will be established and rebuilt using a new design. One of the special conditions of the church of Santa Maria Fatima Magelang is that the majority of the congregation in the church is elderly. The aim of this research is to find natural and artificial lighting designs that can provide visual comfort to the elderly during worship and maintain the spiritual atmosphere in the church of St. Mary Fatima Magelang. This research uses quantitative descriptive methods. The result of this study is the addition of vertical shading to the east side opening to regulate the intensity of light entering the worship room. In the case of artificial lighting, a number of applications of lighting colors, lighting types, angles, and lighting arrangements correspond to the Model 3 study, which has proven to provide visual comfort to the elders as well as a spiritual atmosphere at Mass
Creating An Inclusive Community Activity Center For The Elderly: Fostering Intergenerational Interaction
Get PDFAs individuals transition into their senior years, they often experience declines in both physical and psychological well-being. Consequently, the elderly require specialized services distinct from those provided to younger adults. To address these challenges, the establishment of an elderly community center become essential, offering a range of tailored services derived from informed problem-solving approaches rooted in elderly-related phenomena. While discussions about the elderly tend to focus on their vulnerabilities, they possess a wealth of invaluable life experiences that surpass mere frailty. Their extensive knowledge, skills, life experiences, desires, regrets, and achievements serve as not only sources of nostalgia for the youth but also as a reservoir of knowledge ripe for analysis and transformation into meaningful life lessons. Facilitating intergenerational memories can effectively foster positive interactions between older and younger generations. The envisioned community center embraces an inclusive design approach, crafting an environment accessible to all users. With advancing age, diminished physical mobility and motor function lead to reduced strength and energy among the elderly. Designing spaces with their comfort and safety in mind within the built environment is crucial. This endeavor is informed by community observations, field studies, precedent analyses, and literature reviews, thereby gathering relevant theories to underpin the research. Six design strategies emerge from these investigations: 1) Site selection strategy, 2) Mass composition and building façade strategy, 3) Activity zoning within the building strategy, 4) Access and circulation strategy, 5) Interior space design strategy, and 6) Equipment and furniture strategy. By embracing an inclusive design approach, the planning and analysis encompass strategies for shared activities while ensuring comfort and safety, promoting the development and interaction of both the elderly and younger generations.
Keywords: Elderly Community Center; Intergenerational; Inclusive Desig
Pengukuran Langsung Kurva Karakteristik Air – Tanah (SWCC) Pada Limbah Beton Dengan Metode Tempe Cell
Get PDFAbstrak
Terjadinya peningkatan volume limbah padat akibat pekerjaan konstruksi, sangat berdampak terhadap permasalahan ekologi serius. Dalam praktik rekayasa geoteknik, Capillary Barrier System dikenal sebagai suatu sistem konstruksi ramah lingkungan yang tersusun dari material limbah beton. Secara eksperimental, studi terhadap karakteristik material limbah beton pada kondisi takjenuh masih belum banyak dilakukan saat ini. Tujuan penelitian ini ialah untuk melakukan pengukuran secara langsung terhadap SWCC dan permeabilitas takjenuh pada material limbah beton dengan menggunakan alat Tempe Cell. Pengukuran SWCC berdasarkan alat Tempe Cell dilakukan secara bertahap, dengan mengaplikasikan tekanan udara sebesar 0.5, 1, 3, 5, 10, 20, dan 40 kPa. Adapun hasil data pengukuran, selanjutnya direpresentasikan dalam kurva best fit SWCC yang dianalisis dengan menggunakan fungsi regresi non-linier. Secara statistik, estimasi terhadap fungsi permeabilitas juga dilakukan berdasarkan hasil data pengujian permeabilitas jenuh dan representasi dalam kurva best fit SWCC. Berdasarkan hasil analisis, dapat diketahui bahwa karakteristik dari sifat hidraulik pada material limbah beton memiliki kemampuan penyimpanan air sebesar 31 %, serta pengaliran air dalam kondisi jenuh sebesar 1.12 x 10-5 m/s dan takjenuh sebesar 3.76 x 10-16 m/s.
Kata Kunci : Fungsi permeabilitas, kurva karakteristik tanah-air, limbah beton, tempe cell.
Abstract
The rise in solid waste from construction activities significantly impacts ecological issues. In geotechnical engineering practice, the Capillary Barrier System is an environmentally friendly construction system composed of concrete waste materials. Experimental studies on the characteristics of concrete waste materials under unsaturated conditions haven't been widely conducted at this time. The purpose of this study was to directly measure the SWCC and unsaturated permeability of concrete waste materials using the Tempe Cell. SWCC measurements based on the Tempe Cell were performed in stages, applying air pressures of 0.5, 1, 3, 5, 10, 20, and 40 kPa. The measurement data results were then presented in the SWCC best-fit curve, which was analyzed using a non-linear regression function. A statistical estimation of the permeability function was carried out using data from the saturated permeability tests and the SWCC best-fit curve. Based on the analysis results, it is evident that the characteristics of the hydraulic properties of concrete waste material have a water storage capacity of 31 % and water flow in saturated conditions of 1.12 x 10-5 m/s and unsaturated conditions of 3.76 x 10-16 m/s.
Keywords: Concrete waste, permeability function, soil-water characteristic curve, tempe cell.Abstrak
Terjadinya peningkatan volume limbah padat akibat pekerjaan konstruksi, sangat berdampak terhadap permasalahan ekologi serius. Dalam praktik rekayasa geoteknik, Capillary Barrier System dikenal sebagai suatu sistem konstruksi ramah lingkungan yang tersusun dari material limbah beton. Secara eksperimental, studi terhadap karakteristik material limbah beton pada kondisi takjenuh masih belum banyak dilakukan saat ini. Tujuan penelitian ini ialah untuk melakukan pengukuran secara langsung terhadap SWCC dan permeabilitas takjenuh pada material limbah beton dengan menggunakan alat Tempe Cell. Pengukuran SWCC berdasarkan alat Tempe Cell dilakukan secara bertahap, dengan mengaplikasikan tekanan udara sebesar 0.5, 1, 3, 5, 10, 20, dan 40 kPa. Adapun hasil data pengukuran, selanjutnya direpresentasikan dalam kurva best fit SWCC yang dianalisis dengan menggunakan fungsi regresi non-linier. Secara statistik, estimasi terhadap fungsi permeabilitas juga dilakukan berdasarkan hasil data pengujian permeabilitas jenuh dan representasi dalam kurva best fit SWCC. Berdasarkan hasil analisis, dapat diketahui bahwa karakteristik dari sifat hidraulik pada material limbah beton memiliki kemampuan penyimpanan air sebesar 31 %, serta pengaliran air dalam kondisi jenuh sebesar 1.12 x 10-5 m/s dan takjenuh sebesar 3.76 x 10-16 m/s.
Kata Kunci : Fungsi permeabilitas, kurva karakteristik tanah-air, limbah beton, tempe cell.
Abstract
The rise in solid waste from construction activities significantly impacts ecological issues. In geotechnical engineering practice, the Capillary Barrier System is an environmentally friendly construction system composed of concrete waste materials. Experimental studies on the characteristics of concrete waste materials under unsaturated conditions haven't been widely conducted at this time. The purpose of this study was to directly measure the SWCC and unsaturated permeability of concrete waste materials using the Tempe Cell. SWCC measurements based on the Tempe Cell were performed in stages, applying air pressures of 0.5, 1, 3, 5, 10, 20, and 40 kPa. The measurement data results were then presented in the SWCC best-fit curve, which was analyzed using a non-linear regression function. A statistical estimation of the permeability function was carried out using data from the saturated permeability tests and the SWCC best-fit curve. Based on the analysis results, it is evident that the characteristics of the hydraulic properties of concrete waste material have a water storage capacity of 31 % and water flow in saturated conditions of 1.12 x 10-5 m/s and unsaturated conditions of 3.76 x 10-16 m/s.
Keywords: Concrete waste, permeability function, soil-water characteristic curve, tempe cell