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All Journal Portal: Jurnal Teknik Sipil JURNAL TEKNIK SIPIL UNAYA
Fajri Fajri
Politeknik Negeri Lhokseumawe
Civil Engineering, Building, Construction & Architecture Materials Science & Nanotechnology

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Pengaruh Penambahan Serat Tali Rafia terhadap Sifat Mekanis Mortar Geopolimer Fajri Fajri
Portal: Jurnal Teknik Sipil Vol 12, No 2 (2020)
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/portal.v12i2.2015

Abstract

Mortar Geopolimer seperti mortar umumnya, memiliki kekurangan berupa sifat getas dan rendah kekuatan lenturnya. Tujuan penelitian ini adalah untuk melihat pengaruh penambahan serat terhadap sifat mekanis mortar geopolimer yang menggunakan fly ash, sebagai pengganti semen. Serat yang digunakan adalah serat tali rafia yang dipotong sepanjang 2 cm, dengan variasi berat serat 0%, 0,4%, 0,8%, 1,2 % dan 1,6% dari berat fly ash. Benda uji dibuat berbentuk prisma ukuran 30x30x130 mm dan berbentuk kubus ukuran 50x50x50 mm. Pengujian yang dilakukan berupa pengujian kuat lentur dan kuat tekan pada umur mortar 1, 3, 7 dan 28 hari. Dari hasil pengujian diperoleh hasil, nilai kuat lentur maksimum terjadi pada persentase serat 0,8% dan kuat tekan maksimum terjadi pada persentase serat 0,4%. Peningkatan kuat lentur dan kuat tekan mortar geopolimer masing-masing terjadi sebesar 14,69 % dan 2,18 % dibanding mortar geopolimer tanpa serat pada umur 28 hari.
Analisis Prediksi Korosi Tulangan pada Beton Busa Bertulang dengan Metode Half Cell Potential Mapping Fajri Fajri
Jurnal Teknik Sipil Unaya Vol 7, No 1 (2021): Januari 2021
Publisher : Center for Research and Community Service (LPPM) University of Abulyatama

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30601/jtsu.v7i1.1502

Abstract

Half-cell potential mapping is a simple non-destructive test method for the corrosion of reinforcing steel. This study aim to analyze the prediction of reinforcing corrosion in reinforced foam concrete using the Haf-Cell Potential Mapping method. The test includes mapping of reinforcing steel and measuring corrosion potential. The speciment is beam of 15cm x 20cm x 80cm size. The main reinforcement is  4Ø10mm and stirrup Ø6-10cm, and concrete cover thickness of 20mm. Cement water rasio is  0,4; specifi gravity 1,6 and compressive strength of 25MPa. The specimens were immersed in a 3,5% sodium chloride solution and in well water as a control. Corrosion potential measurements were carried out every 2 weeks for 16 weeks. The results showed that the corrosion potential value increased due to the duration of immersion. The corrosion potential value of the speciment immersed in NaCl solution is.-300mV, the risk of corrosion is 90%. The corrosion potential value of the speciment immersed in well water is -200mV, the risk of corrosion is at 50%. Foam concrete soaked in seawater has a greater risk of corrosion than in well water. But the risk of foam concrete submerged in seawater is still smaller than conventional concrete submerged in seawater.
Pengaruh Variasi Konsentrasi Larutan Naoh 6m Dan 8m Terhadap Penurunan Caco3 Pada Mortar Geopolimer Berbahan Dasar Fly Ash Nagan Raya Aiyub Aiyub; Lia Ramadhaniati; Fajri Fajri
Jurnal Teknik Sipil Unaya Vol 7, No 1 (2021): Januari 2021
Publisher : Center for Research and Community Service (LPPM) University of Abulyatama

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30601/jtsu.v7i1.1505

Abstract

The combination of NaOH and Na2SiO3 in an alkaline solution is able to react with FA  to form Si-O-Si and Si-O-Al gels. Several studies have shown that the high concentration of NaOH causes the appearance of calcium carbonate (CaCO3) on the surface of the specimen. This problem became the concern of this study, the reduction NaOH concentration was investigated to reduce CaCO3. The results showed that the chemical composition of FA Nagan Raya (FANR) contained Si, Al, and Ca compounds which were respectively around 37.16%, 17.61%, and 8.72%. XRD analysis shows that the main peaks of the FANR material and paste are in the 20 to 30 2θ region. FTIR analysis showed that the peak of the band 1380cm-1 - 1450cm-1, showed that the CaCO3 was bent in the FANR paste. The TGA analysis shows that the weight loss of FANR paste is higher than material of FANR. Low NaOH concentration has decreasing workability which causes faster setting time and reduces compressive strength. However, the use of a low concentration of NaOH solution can reduce CaCO3 on the surface of spesimen.
Co-Authors Aiyub Aiyub Lia Ramadhaniati