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Performance Changes in Mass and Compressive Strength of High-Calcium Fly Ash Based Geopolymer Concrete Due to Sodium Sulphate Exposure Tajunnisa, Yuyun; Husin, Nur Achmad; Kusbiantoro, Andri; Daffa Azmi, Ahmad; Fadilah Ashara, Khansa; Shigeishi, Mitsuhiro
IPTEK The Journal of Engineering Vol 10, No 1 (2024)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v10i1.a16232

Abstract

The sulfate environment is one of the conditions that significantly affect the durability of concrete. Sulfate attack causes cracks and affects the quality of the concrete. Therefore, it is necessary to innovate concrete that can withstand the aggression of this sulfate attack. Geopolymer concrete is a breakthrough that can be developed as an alternative material without using Portland cement as the ingredients, yet by using class F fly ash as the primary source material. On the other hand, the availability of class C fly ash with high CaO content is highly abundant in Indonesia. The high calcium content in this fly ash will cause the fresh geopolymer concrete to harden rapidly. Previous studies used sucrose as an additive to overcome this rapid hardening problem. However, its effect on the geopolymer concrete exposed to sulfate ingression requires further investigation. In this study, the geopolymer concrete was produced by using class C fly ash and sucrose. The sulfate ingression was simulated by immersing the concrete specimen in the sodium sulfate solution while the mass changes and compressive strength were examined. pH measurement of the sodium sulfate solution was also carried out to provide a different perspective on the data analysis. Cylindrical specimens, measuring 10 cm x 20 cm, were produced using the dry-mixing method and the characteristic strength of 28 MPa according to SNI 2847–2019. From the results, geopolymer concrete with sucrose showed a high workability performance through the high slump value obtained. Nevertheless, the experimental results also indicated the declining strength of geopolymer concrete after the sulfate exposure. However, only a slight reduction was observed. The strength residue still satisfies the minimum requirement of SNI 2847-2019. It shows the potential of geopolymer concrete to be used as a construction material in a harsh environment with high sulfate content.
Tensile Performance of Inter-Module Connections for Modular Steel Buildings Using Finite Element Method Shoifah, Umi Arifatus; Husin, Nur Ahmad; Tajunnisa, Yuyun
IPTEK The Journal of Engineering Vol 11, No 3 (2025)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v11i3.a23072

Abstract

Steel modular construction is an innovative technology that uses prefabricated volumetric module units manufactured in a factory and assembled on site via inter-module connections. However, this system's application in high-rise buildings is limited because the structural performance is strongly influenced by the inter-module connection mechanism. This technology uses a translational spring model to transfer loads between modules through inter-module connections. This approach uses threaded steel rod components, connection plates, shear keys, shear plates, and tie plates. This research aims to determine the maximum tensile capacity of the connection. It also aims to study stress distribution due to tensile forces and failure modes in vertical modular connections. This research uses the finite element method (FEM) to perform numerical analysis by applying monotonic loads. Simulation results indicate that the connection's maximum tensile capacity is 307.48 kN, distributed among two rods with capacities of 153.74 kN each at a displacement of 23.2 mm. The rod undergoes elastic deformation up to Fy = 900 MPa, followed by a plastic phase up to nearly Fu = 1,100 MPa, causing permanent strain and necking. Tensile failure occurred due to plasticity and necking conditions.
Cyclic Behavior of Slender Shear Walls with Ultra High Performance Fiber Reinforcement Concrete Overlays Arifa, Geralda Nurry; Amalia, Aniendhita Rizki; Tajunnisa, Yuyun
Reka Buana : Jurnal Ilmiah Teknik Sipil dan Teknik Kimia Vol 10, No 2 (2025): EDISI SEPTEMBER 2025
Publisher : Universitas Tribhuwana Tunggadewi Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33366/rekabuana.v10i2.8126

Abstract

Shear walls serve as the primary structural elements for resisting lateral loads induced by earthquakes; however, slender shear walls remain susceptible to shear failure and buckling, particularly in structures designed according to older design codes. One strengthening technique that has gained increasing attention is the application of Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) overlays, which offer high strength and effective crack control capabilities. This study aims to analyze the cyclic behavior of slender shear walls strengthened with a two-layer UHPFRC overlay with a total thickness of 40 mm using a finite element method based on the Concrete Damage Plasticity (CDP) model implemented in Abaqus. The numerical model is validated using experimental data from conventional reinforced concrete shear walls and UHPFRC-strengthened shear walls by comparing force–displacement responses, hysteresis curves, and tensile damage (Damage) distributions. The validation results indicate that the numerical model accurately captures the structural response, as evidenced by the close agreement in maximum displacement and damage mechanisms, with displacement differences of 2.97% for the conventional shear wall and 0.18% for the UHPFRC-strengthened shear wall. Parametric analysis shows that the UHPFRC overlay significantly increases the maximum load capacity from 328.22 kN to 525.37 kN, enhances the initial stiffness and first-yield capacity, and reduces the maximum displacement from 127.79 mm to 112.50 mm. Furthermore, the UHPFRC-strengthened shear wall exhibits a more stable post-peak response, fuller hysteresis loops, higher energy dissipation capacity, and more localized and gradually developing tensile damage compared to the conventional shear wall. These results demonstrate that a 40 mm-thick two-layer UHPFRC overlay effectively improves the shear capacity, cyclic stability, and seismic resistance of slender shear walls.
The Effect of Sulfate Exposure on The Mechanical Properties of Conventional Portland Composite Cement Concrete Hazen Masrafat; Wahyuniarsih Sutrisno; Yuyun Tajunnisa
Journal of Civil Engineering Vol. 39 No. 2 (2024)
Publisher : Institut Teknologi Sepuluh Nopember (ITS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20861206.v39i2.7287

Abstract

The durability of concrete is an essential factor in construction as a means to enhance the quality of public facilities planning. The durability of concrete structures can be degraded due to several factors, one of the factors is sulfate attack concrete. Expose to magnesium sulfate (MgSO4) causes more aggressive damage compared to sodium sulfate. The negative effect of sulfate exposure is the accelerated formation of microcracks that lead to concrete deterioration. This study aims to investigate the influence of expose to a 5% magnesium sulfate solution on the mechanical properties of Portland composite cement concrete (PCC). Sulfate exposure was conducted after the PCC concrete was cured in water for 28 days. Observations and testing were carried out in four stages: before exposure, after 28, 56, and 90 days. The compressive strength of the concrete increased by 8.78% after 56 days of exposure but decreased by 7.2% from the 56-day strength during the 90-day exposure. The modulus of elasticity, Poisson's ratio, tensile strength, and fracture energy were directly proportional to the compressive strength values generated during sulfate exposure. Additionally, the mass of the concrete increased by 0.87% after 56 days of exposure and then decreased to 0.56% during the 90-day exposure.
The Effect of Bar Diameter on Bond Stress of Geopolymer Concrete with Pull-out Test Khansa Fadilah Ashara; Bambang Piscesa; Yuyun Tajunnisa
Journal of Civil Engineering Vol. 39 No. 1 (2024)
Publisher : Institut Teknologi Sepuluh Nopember (ITS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20861206.v39i1.7331

Abstract

Geopolymer concrete, an eco-friendly alternative, employs silica, alumina, and alkaline activators. While wet mixing has been extensively studied, its limitations, such as impracticality, quick setting, and low workability, are overcome by the dry mixing method. Study by previous research is limited only to compressive strength, flexural strength, and shrinkage. However, research on bond strength, crucial for concrete-reinforcement adhesion, is limited. This study investigates bond strength through pull-out tests using consistent concrete materials, including Type C fly ash, 12M NaOH, and an alkali ratio of 1:1. Specimens with varying reinforcement diameters (D10, D12, D16) and additional transverse reinforcement (f6-150) were tested. Bond stress averages at D10, D12, and D16 are 25.80 MPa, 25.36 MPa, and 24.25 MPa. Reinforcement diameter directly influences bond strength, with larger diameters yielding greater bond stress.
An Experiment of Shear Strength Reinforced Geopolymer Concrete Beam Based High-Calcium Fly Ash with Varian Shear Span-to-Depth Ratio Moh. Safi’i Mansur; Priyo Suprobo; Yuyun Tajunnisa; Auliagitta Kumala Apsari
Journal of Civil Engineering Vol. 38 No. 3 (2023)
Publisher : Institut Teknologi Sepuluh Nopember (ITS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20861206.v38i03.7452

Abstract

This study discusses geopolymer-reinforced concrete beam's shear strength capacity by experimental observation using high-calcium fly ash as the main binder. This study observed the influence of shear span per effective depth ratio due to the geopolymer concrete beam's shear behavior and strength capacity. Two beams are designed to have diagonal tensile cracks; hence the shear failure state could be obtained. Each beam has similar properties by 150 mm in width, 250 mm in height, 1800 mm in length, 2D16 as the flexure bar reinforcement, and stirrups of Ø6-250 with 20 mm concrete cover. The research employed the four-point load bending testing with the load span difference of each beam, which will later be the study variable. The things sought in this study include the peak load-deflection curve, the shear capacity that occurs in geopolymer concrete beams, and the shear capacity comparison with ACI 318-19. The results of the tests that have been carried out show that type A geopolymer-reinforced concrete beam was more ductile than type B beams, with a percentage difference of about 21.49% in deflection. The shear strength at the ratio a/d of 2 was 115,04 kN, and the ratio a/d of 2.5 was 89,00 kN. As well as a comparison of the shear strength of the test results with calculations according to ACI 318-19 shows a ratio of 1.69. So it can be concluded that ACI 318-19 calculations were conservative.
NUMERICAL INVESTIGATION OF GEOPOLYMER REINFORCED CONCRETE BEAMS UNDER FLEXURAL LOADING USING 3DNLFEA Yosi Noviari Wibowo; Bambang Piscesa; Yuyun Tajunnisa
Journal of Civil Engineering Vol. 37 No. 1 (2022)
Publisher : Institut Teknologi Sepuluh Nopember (ITS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20861206.v37i1.7628

Abstract

This paper deals with numerical modeling of geopolymer reinforced concrete loaded under flexure using nonlinear finite element analysis. The modeled specimen was obtained from the existing literature and is tested under the four-point bending load. The numerical simulation uses an in-house limited element package called 3D-NLFEA, which utilizes ordinary concrete's multi-surface plasticity model. Since the concrete constitutive model used is for ordinary Portland cement, adjusting the input parameter is required to predict the behavior of geopolymer reinforced concrete. The focus on the discussion was limited to the modeling of the specimen, the moment-curvature result, and the crack pattern between the numerical model and the available experimental test. The simulation found that the predicted moment-curvature relationship using the 3D-NLFEA package was 1.3 to 2.4 % lower than the test result. The crack pattern was controlled by flexure, which was observed in the experimental test and numerical simulation. The predicted crack lengths for modeled beam using 3D-NLFEA were within the minimum and maximum measured crack lengths from the test result.
NUMERICAL ANALYSIS STUDY OF THE EFFECT GEOPOLYMER CONCRETE COMPRESSIVE STRENGTH ON DUCTILITY OF REINFORCED CONCRETE BEAMS Muhammad Wildan Aziz; Priyo Suprobo; Yuyun Tajunnisa
Journal of Civil Engineering Vol. 37 No. 1 (2022)
Publisher : Institut Teknologi Sepuluh Nopember (ITS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20861206.v37i1.7629

Abstract

Geopolymer concrete that has polymer formwork is very likely to be used as reinforced concrete material with several advantages. The advantages of geopolymer concrete when compared to portland cement concrete are: resistant to acidic environments (corrosion resistance), better bond strength of reinforcement with concrete material, stable at high temperatures, higher fracture energy. Previous experimental studies found that the tensile strength, bond strength, and fracture energy of geopolymer concrete were better, leading to the hypothesis that the ductility value of geopolymer concrete was better than portland cement concrete. The identification of ductility values based on the compressive strength of concrete will be carried out in research using the finite element method using the 3D ATENA program. Several specimens with compressive strength of 25 MPa, 30 MPa, 35 MPa, 40 MPa, and 45 MPa were compared with their ductility values. The results showed that the 25 MPa specimen had the highest ductility value with 5.33, while the lowest ductility value is 45 MPa specimen with 3.39.
Co-Authors Affandhie, R. Buyung Anugrah Affandhie, R. Buyung Anugraha Affandhie, Raden Buyung Anugraha Ahmad Basshofi Habieb Ahmad Basshofi Habieb Alam, Rizki Robbi Rahman Alfayet, Muhamad Rifki Aniendhita Rizki Amalia Apsari, Auliagitta K. Apsari, Auliagitta Kumala Arifa, Geralda Nurry Arrafid, Rifqi Nadhif Arwinda Aribah Cahyani Ashara, Khansa Fadilah Auliagitta Kumala Apsari Auliagitta Kumala Apsari Bambang Piscesa Basshofi Habieb, Ahmad Bayuaji, Ridho Beta Rahayuning Pratiwi Budi Suswanto Budi Suswanto Budi Suswanto Butje Alfonsius Louk Fanggi Cahyani, Arwinda Aribah Chadaffi, Muchamad Daffa Azmi, Ahmad Darmawan, Muhammad Sigit Data Iranata Data Iranata Dicky Imam Wahyudi Dicky Imam Wahyudi Dicky Imam Wahyudi Diputra, Aditya Tamateja Djoko Sulistiono Fadilah Ashara, Khansa Fikri Ghifari Fikri Ghifari Geralda Nurry Arifa Habibillah Asyari, Yudhistira Halisah, Vonny Nur Hariyanto, Ifarrel Rachmanda Hazen Masrafat Hendro Nurhadi Husin, Nur Achmad Husin, Nur Ahmad Ibnu Pudji Rahardjo Ibnu Pudji Rahardjo Ibnu Pudji Raharjo Indra Komara Indra Komara, Indra Jonatan Lassa Jonatan Lassa Jusuf Wilson Meynerd Rafael Jusuf Wilson Meynerd Rafael Khansa Fadilah Ashara Khoiri, Mohamad Kuntjoro Kusbiantoro, Andri Louk Fanggi, Butje Alfonsius M. Faishal Darmawan Machsus Machsus Mansur, Moh Safii MANSUR, MOH. SAFI'I Mansur, Moh. Safi’i Masiran, Hidajat Sugihardjo Mawardi, Amalia Firdaus Meynerd Rafael, Jusuf Wilson Mitsuhiro Shigeishi Mochammad Ahdian Wildan Nafi Moh. Safi’i Mansur Mohamad Khoiri Muhammad Hafiizh Imaaduddiin Muhammad Sigit Darmawan Muhammad Sigit Darmawan Muhammad Wildan Aziz Muhammad Wildan Aziz Nur Achmad Husin Nur Achmad Husin Nur Achmad Husin Nurhadi, Hendro Paramitha, Kharisma Keysia Piscesa, Bambang Priyo Suprobo Priyo Suprobo Purnamasari, Ragil R. Buyung Anugraha Affandhie R. Buyung Anugraha Affandhie Raden Buyung Darmawan Rahardjo, Ibnu Pudji Ralindra, Deris Faisa Ramadhaniawan, Virdy Ridho Bayuaji Ridho Bayuaji Rijiyawanto, Adetya Shigeishi, Mitsuhiro Shoifah, Umi Arifatus Sigit Darmawan Sigit Darmawan Sita Auliyah Rahmasari Siti Kamilia Aziz Srie Subekti Subekti, Srie Sulchan Arifin Sulchan Arifin Sungkono Karsidi Sungkono Karsidi Sungkono Sungkono Sungkono Sungkono Suprobo, Priyo Suswanto, Budi Sutrisno, Wahyuniarsih Sutrisno, Wahyuniarsih Suwandi Suwandi Suwandi Suwandi Suwandi Syifaul Ummah, Galih Tatas, Tatas Tatas, Tatas Wahyuniarsih Sutrisno Wibowo, Yosi Noviari Wibowo, Yosi Noviari Wilujeng, Susi A Yanisfa Septiarsilia Yosi Noviari Wibowo Yosi Noviari Wibowo Yudoprasetyo, Kohar Zanah, Miftaqul