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All Journal J-Sil (Jurnal Teknik Sipil dan Lingkungan) Journal of the Civil Engineering Forum
Hideaki Yasuhara
Ehime University
Civil Engineering, Building, Construction & Architecture Earth & Planetary Sciences Engineering Environmental Science Transportation

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The Utilization of Soybean as a Catalyst Material in Enzyme-Mediated Calcite Precipitation (EMCP) for Crack Healing Concrete Regina Aprilia Zulfikar; Heriansyah Putra; Hideaki Yasuhara
Journal of the Civil Engineering Forum Vol. 7 No. 1 (January 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.57889

Abstract

The effect of using soybean as a catalyst in the Enzyme-Mediated Calcite Precipitation (EMCP) method of crack healing concrete is discussed in this research. The existence of cracks in concrete reduces its quality, therefore, there is the need for repair efforts and one of these is through injection using the EMCP method. This technique employs the plant-derived urease enzyme to catalyze the reaction between calcium chloride (CaCl2) and urea (CH4N2O) towards precipitating calcium carbonate (CaCO3). Its effectiveness was, however, evaluated using a test tube experiment, and the optimum combination of urease, urea, and calcium chloride was selected and used as the preliminary data for the soybean added as a catalyst. Meanwhile, the concrete samples were prepared in the form of 5 cm x 10 cm cylindrical concrete and the crack was made through Universal Testing Machine (UTM) with a controlled area observed to be in the range of ± 0.2-0.3 mm. The injection solution was added to the concrete using the percolation method up to the period the height of the solution was 5 mm above the concrete surface and this was conducted several times with the effect on the concrete cracks evaluated through permeability tests which were used as one of the concrete quality parameters. Moreover, the permeability coefficient value was found to be inversely proportional to the quality and this means a smaller value of the coefficient produced better concrete quality and vice versa. The results showed the total calcite formed in the sample after the 4th injection was 18.3% of the total surface area of the concrete crack and was able to reduce the concrete permeability value by 95.43%. This, therefore, means the use of soybean in the EMCP method is considered feasible to repair concrete cracks.
Pengaruh Variasi Ukuran Butiran Tepung Kedelai pada Metode Calcite Precipitation untuk Peningkatan Kekuatan Tanah Pasir Luthfi Lofianda; Heriansyah Putra; Hideaki Yasuhara
Jurnal Teknik Sipil dan Lingkungan Vol. 8 No. 1: April 2023
Publisher : Departemen Teknik Sipil dan Lingkungan, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jsil.8.1.29-36

Abstract

Kedelai merupakan alternatif penggunaan enzim urease murni komersial dalam metode calcite precipitation. Ukuran butiran tepung kedelai merupakan salah satu faktor penting karena berpengaruh terhadap jumlah material yang tidak terlarut dan selanjutnya terhadap reaksi pembentukan kalsit. Tepung kedelai yang digunakan dalam penelitian ini telah diayak dengan saringan No. 300 (50 μm), No. 150 (100 μm), dan No. 75 (200 μm) dan bagian yang tertahan di setiap saringan digunakan dalam penelitian. Larutan tepung kedelai dengan konsentrasi sebanyak 20 g/L digunakan dan disaring melalui saringan No. 400 (40 μm), untuk mendapatkan ekstrak. Pasir Bangka digunakan sebagai sampel tanah pasir dan memiliki koefisien keseragaman sebesar 1.53. Evaluasi kemudian dilakukan dengan mengggunakan tiga parameter yaitu pengendapan kalsit, laju hidrolisis urea, dan evaluasi calcite content menggunakan asam klorida. Berdasarkan uji pengendapan kalsit dengan menggunakan tabung, semakin kecil ukuran biji kedelai, semakin banyak bahan tak terlarut yang dihasilkan. Rasio presipitasi kalsit dan massa kalsit yang diendapkan optimum tercapai pada ukuran butiran kedelai 100 μm. Laju hidrolisis tertinggi terjadi pada ukuran butiran kedelai 50 μm pada 752 U/g. Persentase kalsit tertinggi di dalam sampel terbentuk pada sampel dengan ukuran butiran kedelai 50 μm dengan persentase massa kalsit sebesar 0.60% atau setara dengan 43.81 kPa. Berdasarkan parameter yang dievaluasi, tepung kedelai dengan ukuran 50 μm memiliki hasil terbaik dan penurunan ukuran butiran tepung kedelai sejalan dengan peningkatan kekuatan tanah pasir.
Co-Authors Luthfi Lofianda Putra, Heriansyah Regina Aprilia Zulfikar