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PENGGUNAAN SERAT TANDAN KOSONG SAWIT DALAM PENINGKATAN KEKUATAN PADA BETON BERSERAT Henny Lydiasari; Ari Yusman Manalu; Rahmi Karolina
Jurnal Penelitian Kelapa Sawit Vol 25 No 3 (2017): Jurnal Penelitian Kelapa Sawit
Publisher : Pusat Penelitian Kelapa Sawit

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (169.277 KB) | DOI: 10.22302/iopri.jur.jpks.v25i3.33

Abstract

The potency of oil palm empty fruit bunches (OPEFB) fibers as one of the by-products of processing oil palm is increasing significantly so that proper management is needed in reducing environmental impact. One of the utilization of OPEFB fibers is as a substitution material in construction which usually the material is derived from non-renewable mining materials so that the number is increasingly limited. Therefore, it is necessary to study to know the performance of OPEFB fiber in making construction products especially concrete. In this case, the experiment was conducted using experimental method with variation of fiber addition by 0%, 10%, 15%, 20%, 25%, and 30%. Each specimen was tested by weight, slump value, compressive strength, tensile strength, elasticity and crack length. As the results, the variation of fibers addition by 10%, decrease of slump value is 7%, concrete weight is 3% and crack length is 8% while increase of the compressive strength is 2.7% and the modulus of elasticity is 33.3% but its tensile strength decreased insignificantly by 0.05% . Furthermore, the addition of fibers above 10% to 30% decreased compressive strength is still below 10% and tensile strength below 2% while the weight of concrete, slump value and crack length decreased. Therefore, the addition of 10% can replace the performance of concrete without fiber but the addition of above 10% can still be used on non-structural concrete.
Synthesis of Volcanic Ash-based Geopolymer Mortar Designed by the Taguchi Method Rahmi Karolina; Johannes Tarigan; M. A. Megat Johari; M. J. A. Mijarsh; Harianto Hardjasaputra
Civil Engineering Journal Vol 8, No 11 (2022): November
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2022-08-11-016

Abstract

This study focuses on the geopolymer synthesized from Mount Sinabung’s volcanic ash. The compressive strength of the geopolymer was determined by optimizing five factors using the Taguchi method’s L16 array. The five factors included: volcanic ash wt.%, Sodium silicate (Na2SiO3) wt.%, Sodium hydroxide (NaOH) concentration (mole), Na2SiO3/NaOH wt.% and water/binder (w/b) wt.%. A total of 16 mixtures were prepared per the L16 array and evaluated on five levels to obtain the optimum mixture. The main findings of this study revealed that A2B1C2D3E4 produced the highest compressive strength of 79.625 MPa after three days of curing time, while A4B2C3D1E4 produced the lowest compressive strength of 41.93 MPa. The signal-to-noise (S/N) ratio analysis from the Taguchi method shows that the factor of Na2SiO3 has a greater impact on compressive strength. The X-ray diffraction (XRD) result for the geopolymer mortar revealed the formation of aluminosilicate type (N-A-S-H) and calcium silicate (C-S-H) gels, whereas the Scanning Electron Microscopy (SEM) result exhibited numerous pores and a denser structure. These characterization results demonstrated that the polymerization of volcanic ash mortar from Sinabung successfully conserves natural resources. Doi: 10.28991/CEJ-2022-08-11-016 Full Text: PDF
OPTIMIZATION OF PROJECT TIME AND COST IN PANDEMIC ERA BY TIME COST TRADE OFF METHOD OF UNIVERSITAS NEGERI MEDAN CASE STUDY Gea Geby Aurora Syafridon; Syahrizal; Rahmi Karolina; Muhammad Agung Putra Handana; Maria Christin
Jurnal Ilmiah Teknik Sipil Agregat Vol. 2 No. 2 (2022): Edisi November
Publisher : Jurusan Teknik Sipil, Politeknik Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51510/agregat.v2i2.755

Abstract

The quality of project construction is constrained by the triangle model of project management, refers to the boundaries of scope, cost and time. The construction project at Universitas Negeri Medan is one of the projects that is experiencing delays and does not meet one of the limitations of triple constraints that must be met by each project. This study has aims to identify the acceleration of project duration using the Time Cost Trade Off method with alternative additions of working hours (overtime) 1 hour, 2 hours, and 3 hours as well as the addition of the number of workers by 10%, 15%, 20%, and 25% from the beginning. From the results of the analysis using this method, it was concluded that the addition of the number of workers as much as 10% from the original is more profitable, where the optimum time of acceleration of the project duration is for 171 calendar days and the optimum cost resulting from the acceleration of the project duration is Rp. 14,059,057,900.00.
EXPANSION OF THE READING SPACE BUILDING TO IMPROVE THE QUALITY OF EDUCATION FOR COMMUNITY CHILDREN BELAWAN NELAYAN Riza Inanda Siregar; Rahmi Karolina; Muhammad Agung Putra Handana; Syahrizal
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 3 No. 2 (2018): ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1057.954 KB) | DOI: 10.32734/abdimastalenta.v3i2.4037

Abstract

The condition of the reading hut, which only has the pillars of non-structural wood which has a short wooden life, requires the community to periodically replace the rotten wood pillars. Of course this will take a lot of time and costs. Children and adults at the service location have good reading interests. They routinely visit the floating reading hut, but lately people's interest has diminished because the condition of the floating library is not feasible. The woods of the floating library building are decayed and not suitable to be occupied. Especially the foundation or pillar of the building can no longer be able to survive firmly. These things are the background of the community service activities team to choose the location to be able to apply civil engineering in making foundation or as a pillar of the floating library building of Belawan Fishermen's Village. The main thing and priority that becomes the problem in theFishermen Village which is the service partner is the reading hut that is used by the children of the Belawan Fishermen Village whose capacity is inadequate. The reading lodge does not have a terrace that can be used by local children to play and learn. In addition, the terrace can be used to prevent rainwaterfrom entering the main room of the reading cottage. The solution offered in this program is the expansion of the reading hut in the form of a decent terrace to be used by the children of the Belawan Fishermen Village community to learn and play. The expansion of the reading hut consists of concrete pile foundations and floor plates from wooden planks or plywood boards with zinc roofs.
Panel products made of oil palm trunk bagasse (OPTB) and MMA (Methyl methacrylate)-styrofoam binder Nuryawan, Arif; Jajang Sutiawan; Bayu Tirto Utomo; Iwan Risnasari; Rahmi Karolina; Nanang Masruchin
Global Forest Journal Vol. 1 No. 01 (2023): Global Forest Journal
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/gfj.v1i01.13245

Abstract

The waste product left over from pressing or extracting oil palm trunk (OPT) for sugar purposes is known as oil palm trunk bagasse (OPTB). This residue contains mainly vascular bundles and small amount of parenchyma. These materials are potentially utilized for making panel products such as particleboard (OPTBparticleboard). Objective of this study was to evaluate physical mechanical properties of OPTB-particleboard. For preserving the durability, this work was intended to apply 15% mixture of methyl methacrylate (MMA) cured with Styrofoam as the binder with a ratio (w/w) of 3:1. OPTB-particleboard was made according to the Japanese Industrial Standard (JIS A5908: 2003) with a target density of 0.75 g/cm3 and dimensions of 25 x 25 x 1 cm3. Hot pressing was a condition set at a pressure of 30 kg/cm2 and a temperature of 160 °C for 15 minutes. Physical and mechanical properties were tested according to JIS A 5908:2003 standard. The results showed that physical and mechanical properties of the OPTB-particleboard did not meet the standard. The characteristics of OPTB still easily absorb water even though MMA-Styrofoam should hinder water ingress. Additionally, the poor quality of the OPTB-particleboard was primarily due to the binder's inadequate composition. Optimum values reached when IB, MOR, and MOE were 0.026 MPa, 6.69 MPa, and 892 MPa, respectively. Based on the analysis of variance, it can be concluded that there is no influence on the bottom, middle and upper parts of the origin of the OPTB except for the MOR.
Perawatan Pasangan Dinding Guna Meningkatkan Kenyamanan Kegiatan Belajar Mengajar SDN 067775 Harahap, Fatimah Insani; Karolina, Rahmi; Handana, Muhammad Agung Putra; Hayati, Titi
Jurnal Pengabdian Kepada Masyarakat dan Desa Volume 3, Nomor 1, Juli 2025
Publisher : Politeknik Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51510/passa.v3i1.2384

Abstract

Pemeliharaan dinding sekolah penting untuk menjaga keselamatan, kesehatan, dan kenyamanan lingkungan belajar. Dinding yang rusak atau lembap dapat membahayakan secara struktural dan berdampak buruk pada kesehatan serta efisiensi energi. Pemeliharaan yang baik membantu mencegah pertumbuhan jamur dan menjaga kualitas udara. Perawatan preventif untuk kerusakan yang sering dialami dinding yaitu pemeliharaan rutin dan perbaikan kecil pada dinding dapat mencegah kerusakan besar yang membutuhkan biaya lebih mahal di kemudian hari. Kegiatan ini bertujuan untuk memperbaiki kondisi ruang kelas melalui pengecatan di SD Negeri 067775. Proses dimulai dengan identifikasi kerusakan, lalu dilakukan pemeliharaan secara langsung. Hasil kegiatan menunjukkan peningkatan kualitas dinding dan estetika ruangan kelas, yang berkontribusi dalam terciptanya proses belajar mengajar yang lebih baik.