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All Journal Jurnal Penelitian Pendidikan IPA (JPPIPA) Civil Engineering Dimension
Chikako Fujiyama
Yokohama National University
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Education Materials Science & Nanotechnology Physics

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Improving Geopolymer Characteristics with Addition of Poly-Vinyl Alcohol (PVA) Fibers Januarti Jaya Ekaputri; Chikako Fujiyama; Nobuhiro Chijiwa; Tu Dac Ho; Hung Thanh Nguyen
Civil Engineering Dimension Vol. 23 No. 1 (2021): MARCH 2021
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (606.075 KB) | DOI: 10.9744/ced.23.1.28-34

Abstract

This paper presents the benefits of PVA fibers in improving the mechanical properties of class F fly-ash-based geopolymer concrete. The activator used in the geopolymer was 8M sodium hydroxide (NaOH) and sodium silicate (Na2SiO3), with a mass ratio of Na2SiO3 to NaOH varied from 1.5 to 2.5. Cylindrical specimens with a diameter of 100 mm and a height of 200 mm were prepared for mechanical strength tests. The PVA fibers in the geopolymers were fixed at 0.4%, 0.6%, and 0.8% by total volume. Some mechanical tests were carried out, including compression, splitting, direct tensile and elastic modulus tests. It was found that the mixture with a ratio of alkalis of 1.5 and the PVA fiber content of 0.4% had the best workability. The highest compressive strength was obtained in a mixture with alkali activator ratios of 1.5 and 2.0, and with 0.6% fiber addition. The ratio of the tensile (and splitting-tensile) strength to compressive strength was found to increase with the certain amount of PVA fibers and the ratio of the alkali activators. The workability issue and fiber direction in the concrete were the dominant factors influencing the properties of geopolymer concrete.
Flocculant Assisted Treatment of Suspended Sidoarjo Mud Thilal Syihabuddin; Januarti Jaya Ekaputri; Chikako Fujiyama
Jurnal Penelitian Pendidikan IPA Vol 11 No 11 (2025): November
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v11i11.11880

Abstract

This study investigates the use of lime-based flocculants as a treatment method for Sidoarjo mud (LUSI) to improve solid–liquid separation and reduce the environmental impact of its discharge into the Porong River. Several commercial lime-derived flocculants were tested through jar experiments to evaluate their effectiveness in promoting particle aggregation and enhancing settling behavior under conditions similar to the existing treatment pond. The results indicate that a mud-to-water ratio of 1:4 provided the most efficient sedimentation performance, reflected by faster settling rates and clearer supernatant. Among the flocculants examined, differences in chemical composition and particle morphology influenced the degree of aggregation and overall clarity of the treated water. The treatment substantially reduced turbidity and suspended solids, while also lowering chloride levels in the clarified water. These findings suggest that lime-based flocculants are a feasible option for mitigating the environmental burden of LUSI mud disposal by improving separation efficiency.
Co-Authors Hung Thanh Nguyen Januarti Jaya Ekaputri Nobuhiro Chijiwa Thilal Syihabuddin Tu Dac Ho