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All Journal Science and Technology Indonesia Syntax Literate: Jurnal Ilmiah Indonesia Astonjadro Smart City Makara Journal of Technology Indonesian Geotechnical Journal
Sjah, Jessica
Universitas Indonesia
Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Earth & Planetary Sciences Education Electrical & Electronics Engineering Engineering Environmental Science Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mechanical Engineering Physics Social Sciences Other

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Influence of the Shaping Process on the Tensile Properties of Steel Reinforcement Bars Carbon Steel Grades BJTP24 and BJTS40 Handika, Nuraziz; Idhar, Ridha Amalia; Sjah, Jessica; Arijoeni, Essy; Tjahjono, Elly
Makara Journal of Technology Vol. 24, No. 3
Publisher : UI Scholars Hub

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Abstract

According to the current applicable national standard in Indonesia, i.e. SNI 07 2529 1991, in addition to the limitation on the loading rate, the steel bar must be reduced, formed, or lathed, as part of the shaping process of samples. This study determined and compared the effect of the shaping process on the yield strength, ultimate strength, and percent elongation by conducting tensile tests of steel bar grade BJTS40, i.e. deformed bar type of steel, and grade BJTP24, i.e., plain bar type of steel. Three diameters of the deformed bar (BJTS40) and one diameter of the plain bar (BJTP24) were used. Samples of the bars were taken randomly from a local distributor in the Greater Jakarta area. Each 1 m of the bar is divided into two, i.e. one end being the non-shaped sample and the other end being the shaped sample. Tensile tests of these two sides were conducted. This study determined that the shaping process influences the results of the tensile test, particularly the variation of percent elongation. Moreover, the effects of the shaping process can be inferred from the high coefficients of variation of yield strength (4.33%) and ultimate strength (2.40%) of the shaped sample. The results of this study, which elucidate the effects of the shaping process on tensile tests, can be used as an information resource in engineering practice.
Study of Strain-rate Effect in Two-dimensional Biaxial Test on Granular Material using Discrete Element Method Ananda Putri Swastinitya; Jessica Sjah; James Jatmiko Oetomo
Indonesian Geotechnical Journal Vol. 2 No. 1 (2023): Vol.2 , No.1, April 2023
Publisher : Himpunan Ahli Teknik Tanah Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56144/igj.v2i1.21

Abstract

Numerical study to investigate the effect of various strain rates on global friction angle in the sand has been performed. Granular material behavior is influenced by several factors, among others: pack configuration, grain macro and micro roughness, confinement pressure, loading rate, etc. Sand is a granular material composed of discrete particles that the most refined microscopic techniques are needed to study its mechanical properties. In Indonesia, research related to the Discrete Element Method is still very limited. The two-dimensional discrete element method is capable to calculate the motion and interparticle contacts of large number of small particles, and each particle is modeled as a rigid circular element. The study started with the validation of the DEM model using YADE. Particles with a local friction angle of 35° are arranged in a closed rectangular box (frictionless wall). The number of particles used in this model validation simulation is 1000 sphere-type particles with monodisperse particle gradations. The simulation was done by a drained biaxial test with confinement stress of 100 kPa, thereafter varying strain rate are applied. Based on the deviatoric stress–axial strain curve from YADE, the result can be depicted on the Mohr circle to obtain the value of the global friction angle. It is found that the different value of strain rate affects its global friction angle. Increasing the value of the strain rate can increase the material global friction angle, which increases the strain rate from 1% to 5%, 10%, 25%, and 50% will increase its global friction angle by 5%, 5%, 14%, and 18%, respectively.
Evaluating The Basement Design of Low-Rise Building with Two-Stage Analysis using BIM Integration: Hangar Study Case Tohho, Given; Sjah, Jessica; Rarasati, Ayomi Dita; Trigunarsyah, Bambang
Smart City Vol. 4, No. 1
Publisher : UI Scholars Hub

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Abstract

Building Information Modelling (BIM) has revolutionized the way the construction industry designs, constructs, and manages buildings. Certainly, the utilization of BIM can optimize the usage of materials in a construction project, considering the high level of concrete consumption globally and its significant environmental impact. The implementation of BIM is intended to calculate the volume of concrete and steel material usage in the design process of low-rise buildings with basements, exemplified in this case by a 5-story laboratory hangar with a 1-story basement. The building design is carried out through a two-stage analysis, which involves separating the upper portion from the lower portion of the structure. This analysis procedure is commonly conducted in building design with basements. When designing the lower portion, some practitioners often neglect the lateral soil forces in the global model when designing the column and beam elements, assuming that these forces are sufficiently small and can be accommodated by basement wall reinforcement. In this research, with a shallow basement depth configuration, the study compares the extent of differences in structural dimensions and materials caused by these lateral forces. Significant variations in volume are observed in perimeter columns, primarily due to direct soil loads acting on this area. Additionally, considering the function of these columns as boundary elements for the basement walls, such differences are expected. The application of lateral soil forces on basement walls is determined by the specific basement configuration being designed. This includes assessing whether there are additional walls outside the basement walls, which can be analyzed locally since they are assumed to bear the lateral soil loads occurring. Different analyses yield varying reinforcement and concrete volumes in basement structures, especially between models with and without lateral soil loads, resulting in a 7.73% difference in reinforcement and 4.69% difference in concrete volume.
Modeling Study of Interaction between Fluid Flow and Pipe Wall Formed in Piping Erosion Phenomenon with SPH Method Suntarto, Rut Puspaningtyas; Sjah, Jessica; Rika, R.R. Dwinanti; Bahsan, Erly
ASTONJADRO Vol. 13 No. 1 (2024): ASTONJADRO
Publisher : Universitas Ibn Khaldun Bogor

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Abstract

This study observes the interaction between fluid flow and the solid particles using Smoothed Particle Hydrodynamics (SPH) as a numerical approach with DualSPHysics platform and the flow assumed as a laminar flow with Re of 25, 50, and 100. As an approach study of internal piping erosion phenomenon, there are two types of pipes simulated, pipe with smooth wall and rough wall with different geometry and height of roughness. The geometry of roughness simulated are semi – circular ribs, triangular ribs, and rectangular ribs. The evaluated output of this research is the friction coefficient and velocity distribution occurring. In the case of flow through smooth wall, it is found that the increase of Reynolds number causes the decrease of friction coefficient. The next case of flow through rough walls shows that the height and shape of roughness affect the friction coefficient and velocity contour of the flow.
Sustainable Cement Development Using Palm Oil Boiler Ash: Mechanical and Microstructural Evaluation Suraedi, Daral; Sjah, Jessica; Handika, Nuraziz; Jonbi; Ashari, Ahmad
Science and Technology Indonesia Vol. 10 No. 4 (2025): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2025.10.4.1188-1197

Abstract

The cement industry significantly contributes to CO2 emissions, releasing approximately 1 ton of CO2 for every ton of cement produced, which accounts for up to 40% of total global industrial emissions. This study aims to mitigate these emissions by utilizing Palm Oil Boiler Ash (POBA) as a clinker substitute, creating POBA Cement with substitution levels ranging from 10% to 30%. The POBA was sourced from the Cikasungka Palm Oil Plantation in Bogor, Indonesia and underwent analysis using X Ray Fluorescence (XRF) andScanningElectron Microscopy (SEM) to assess its chemical properties and microstructure. The findings revealed a decrease in compressive strength with increased POBA substitution levels; however, it maintained a pozzolanic effect that supported the crystallization process, albeit with a longer setting time compared to Ordinary Portland Cement (OPC). Notably, the addition of 1% nano-silica was found to enhance compressive strength more effectively than 3%. This research underscores the potential of POBA as an environmentally friendly clinker substitute for sustainable cement production.
Analisis Daur Hidup Proses Produksi Beton RCC dengan Substitusi Parsial Terak Nikel (Studi Kasus Laboratorium Struktur dan Material, Fakultas Teknik, Universitas Indonesia) Pratiwi, Siva Yuniar; Rahmatika, Iftita; Viandila Dahlan, Astryd; Sjah, Jessica; Handika, Nuraziz
Syntax Literate Jurnal Ilmiah Indonesia
Publisher : Syntax Corporation

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36418/syntax-literate.v10i6.60383

Abstract

Concrete is the most widely used construction material in infrastructure development. The main components of concrete consist of coarse aggregate (gravel/split stone), fine aggregate (sand), cement and water. The massive use of natural aggregates raises concerns about their future availability. Nickel slag, which has similar chemical characteristics to natural aggregates, has the potential to be a sustainable substitution material. This study aims to analyze the environmental impact of the Roller Compacted Concrete (RCC) concrete production process with 50% nickel slag substitution for natural aggregates using the Life Cycle Assessment (LCA) approach. The approach used is gate to gate with units per 1 m3 of concrete and analyzed using OpenLCA software and the ReCiPe2016 method. The results of the analysis showed that the RCC concrete compaction stage produced household gas emissions of 1,030.42 kg CO2 eq for Scenario 1 and 1,108.27 kg CO2 eq and for Scenario 2. At the transportation stage, it is known that the largest emission results come from the delivery process of PT. Y to the Laboratory as far as 28 km, which is 1,521.18 kg CO2 eq. Based on these results, it is recommended that the selection of material providers consider comparable mileage to reduce the environmental impact of the transportation process.
Co-Authors Ahmad Ashari Ananda Putri Swastinitya Arijoeni, Essy Bahsan, Erly Bambang Trigunarsyah, Bambang Elly Tjahjono, Elly Handika, Nuraziz Idhar, Ridha Amalia James Jatmiko Oetomo Jonbi Pratiwi, Siva Yuniar Rahmatika, Iftita Rarasati, Ayomi Dita Rika, R.R. Dwinanti Suntarto, Rut Puspaningtyas Suraedi, Daral Tohho, Given Viandila Dahlan, Astryd