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All Journal MEDIA KOMUNIKASI TEKNIK SIPIL Jurnal Online Mahasiswa (JOM) Bidang Pertanian JURNAL SAINTIS KURVATEK Syntax Idea
Ahmad Rifa’i
Civil Engineering Department, Gadjah Mada University, Jogyakarta
Aerospace Engineering Agriculture, Biological Sciences & Forestry Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Electrical & Electronics Engineering Engineering Environmental Science Social Sciences

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Uji Beban Timbunan yang Diperkuat dengan Sistem Pelat Terpaku pada Tanah Gambut Waruwu, Aazokhi; Hardiyatmo, Hary Christady; Rifa’i, Ahmad
MEDIA KOMUNIKASI TEKNIK SIPIL Volume 25, Nomor 2, DESEMBER 2019
Publisher : Department of Civil Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (473.925 KB) | DOI: 10.14710/mkts.v25i2.21018

Abstract

One of the problems with peat soils, when subjected to imposed loads of construction, is the very high compression and long-term excessive settlement. The embankment can be built on peat soil, but it needs reinforcement that can contribute to increasing the stability of the embankment. The nailed slab system, as reinforcement, is expected to reduce settlement and increase the stability of peat soil. The aim of this paper is to study the effect of pile length and distance on the reduction of settlement in both monolithic and non-monolithic piles. The embankment load test was conducted on 70 cm x 120 cm plates, which were reinforced pile with different lengths and distances in the peat soil layer. The analysis was conducted on the reduction settlement of monolithic and non-monolith pile. The results showed that the length and distance of the pile had an effect on the reduction settlement. Changes in pile length are more dominant reducing settlement compared to changes in pile distance. Pile connection with slab has a significant effect on different lengths of piles than different distances piles.
ANALISIS USAHA AGROINDUSTRI JAMU TRADISIONAL SKALA RUMAH TANGGA DI KELURAHAN LABUH BARU TIMUR KECAMATAN PAYUNG SEKAKI KOTA PEKANBARU ', Sarman; Edwina, Susy; Rifa’i, Ahmad
Jurnal Online Mahasiswa (JOM) Bidang Pertanian Vol 2, No 1 (2015): Wisuda February 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Pertanian

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Abstract

This study aims to analyze the revenues, the value added, efficiency, and break even point of traditional herbal medicine agroindustry. The results of this study indicate that the traditional herbal medicine agroindustries in the procurement of primary ingredient and supplementary ingredients did not have a problem. Traditional herbal medicine agroindustries used the traditional technologies and processing was manually. The average gross revenues as much as Rp3,925,480.00 /month or as much as Rp111,614.44/kg of primary ingredient. The average net income Rp1,005,239.79/month or as much as Rp28,582.31/kg of primary ingredient.The average of the families employment income Rp2,882,017.57/ month or as much as Rp81.945,34 /kg of primary ingredient.  The average of value added of the traditional herbal medicine agroindustries Rp2,904,689.87/month or as much as Rp82,589.99/kg of primary ingredient. While the traditional herbal medicine agroindustries was efficient at the RCR average of 1.34, meaning that the traditional herbal medicien agroindustries effort is feasible and efficient to be developed. Keywords: business analysis, traditional herbal medicine agroindustries
Inovasi Pembelajaran Pendidikan Agama Islam Berbasis Blended Cooperative E-Learning Di Masa Pandemi Irsyadiah, Nur; Rifa’i, Ahmad
Syntax Idea Vol 3 No 2 (2021): Syntax Idea
Publisher : Ridwan Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36418/syntax-idea.v3i2.1011

Abstract

The purpose of this research is to find pai learning strategies and ways by using blanded e cooperative e learning methods. The research method used is qualitative research method by observing directly the implementation ofdefensejaran jaurak far in muhammadiyah college branch senen jakarta pusat. The results showed that blanded cooperative e learning method is the ideal solution in dealing with pandemic covid 19. Because this method can bridge the gap between students who have technological means and who do not have them. The combination of cooperative learning and blended learning approaches not only equips students with the ability to understand the material, but more than that can improve communication skills and interpersonal skills, problem solving, critical analysis and other skills needed by students. With the ease of technology, the limitations of classroom meetings can be solved by blended learning.
Perbaikan Sifat Mekanis Tanah Lempung Ekspansif Menggunakan Abu Vulkanis Sinabung dan Kapur Latif, Devi Oktaviana; Rifa’i, Ahmad; Suryolelono, Kabul Basah
JURNAL SAINTIS Vol. 17 No. 1 (2017)
Publisher : UIR Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (173.405 KB)

Abstract

Permasalahan tanah ekspansif dan penangan limbah abu vulkanis merupakan isu penting saat ini. Pemasalahan tanah ekspansif yang tidak menguntungkan dalam konstruksi karena memiliki sifat mudah mengalami perubahan volume akibat pengaruh kelembaban dan air sehingga menyebabkan daya dukungnya rendah sementara limbah abu vulkanis masih perlu mendapatkan perhatian karena akumulasi dan kurangnya lokasi pembuangan. Catatan letusan Sinabung sampai dengan tahun 2016 masih mengalami erupsi dan memuntahkan material vulkanis sehingga penanganan limbah abu vulkanis menjadi perhatian langsung karena akumulasi dan kurangnya lokasi pembuangan. Penelitian ini bertujuan untuk meyelesaikan kedua permasalahan tersebut dengan cara mencampur tanah ekspansif, abu vulkanis dan kapur dengan variasi tertentu dalam rangka memperbaiki sifat mekanis tanah dan mengurangi dampak penumpukan abu vulkanis. Uji yang dilakukan yaitu pemadatan tanah, uji triaxial, uji swelling dan uji swelling potential dilakukan untuk menganalisis pengaruh penambahan limbah abu vulkanis dan kapur terhadap sifat mekanis tanah. Pencampuran limbah abu vulkanis dan bahan kapur dengan tanah ekspansif dapatmeningkatkan berat volume tanah, mengurangi kadar air optimum, peningkatan nilai geser tanah mengurangi perilaku perubahan volume tanah ekspansif. Sehingga material yang dianggap tidak dibutuhkan dan merugikan terhadap lingkungan dan masyarakat memiliki ternyata menjadi keuntungan untuk rekayasa teknik sipil.
EFFECT OF USING LIME AND FLY ASH AS A CEMENT SUBSTITUTE FOR SOIL STABILITY Dias Dwi Hatmoko; Rifa’i, Ahmad; Ismanti, Sito
KURVATEK Vol 9 No 1 (2024): Energy Management and Sustainable Environment
Publisher : Institut Teknologi Nasional Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33579/krvtk.v9i1.4834

Abstract

Subgrade is the lowest layer that receives the load on it if it does not have carrying capacity that is allowed then need for soil stabilization. Chemical soil stabilization is often done with the addition of cement but the use of cement material will cost quite high, it is necessary to alternate other materials for the substitution of cement to reduce the implementation costs incurred. Cement will be replaced as a stabilizing material in this research with additional materials like lime and fly ash. In this research, soil material was taken from the Sentul – Karawang Toll Road Project STA 24+300, with fly ash from PT PUSRI as the stabilization material, and lime material obtained from the market in Yogyakarta. The stabilization material will be used with a fixed lime percentage of 4.2% of the dry weight of the soil, and fly ash at 1.4%, 2.1%, 2.8%, 3.5%, and 4.2% of the dry weight of the soil. The soil samples were tested for physical and mechanical properties, including Standard Proctor and California Bearing Ratio (CBR). All test results were compared to select one variation, which was then designated as the Optimum Mix Design (OMD) sample. The test results of the soil sample + 4.2% lime + 2.1% fly ash yielded a CBR value of 15.52%, indicating an increase of 1078.02% from the initial 1.44%, and were formally designated as an OMD sample. The CBR value satisfies the subgrade requirements, namely >6%.
Co-Authors ', Sarman Aazokhi Waruwu Dias Dwi Hatmoko Hary Christady Hardiyatmo, Hary Christady Irsyadiah, Nur Ismanti, Sito Kabul Basah Suryolelono Latif, Devi Oktaviana Susy Edwina