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Journal : IPTEK The Journal of Engineering

Sulphate Resistance of Geopolymer Concrete Based on High Calcium Fly Ash Yuyun Tajunnisa; Nur Achmad Husin; Indra Komara; Mochammad Ahdian Wildan Nafi; Mitsuhiro Shigeishi
IPTEK The Journal of Engineering Vol 9, No 1 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v9i1.a16235

Abstract

The inclusion of fly ash class C, which is widely available locally, can influence the progress of strength and durability qualities of geopolymer concrete when exposed to significant environmental conditions. Alternative geopolymer combinations appropriate for curing at ambient temperatures were employed to investigate the impacts of fly ash class C based geopolymer concrete. To react with fly ash class C, a combination of sodium hydroxide and sodium silicate alkaline activator was used. Fly ash class C was added as 20% of the total binder without using ordinary Portland cement. The durability of fly ash class C based geopolymer concrete in sulphate environments was tested. The changes in weight, length and compressive strength due to exposure in magnesium sulphate solution for different periods of time were determined. The test results demonstrate that fly ash class C based geopolymer concrete cured at normal temperatures has good resistance to sulphate attack. In general, inclusion of fly ash class C in geopolymer concrete improved strength and performed satisfactorily in sulphate environments when cured in ambient temperature.
Performance of Workability and Compressive Strength on Self-Compacting Geopolymer Concrete Based On High-Calcium Fly Ash With Addictive Admixture Yuyun Tajunnisa; Nur Achmad Husin; Sigit Darmawan; Ridho Bayuaji; Raden Buyung Darmawan; Arwinda Aribah Cahyani
IPTEK The Journal of Engineering Vol 9, No 1 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v9i1.a16237

Abstract

Geopolymer concrete has been developed as a replacement for conventional concrete with other pozzolan materials, which have a high silicate alumina content. Fly ash is a material that contains a high silicate alumina of 22%. The high content of Al and Si increases the compressive strength of concrete. High-calcium fly ash is abundantly found in Indonesia. However, it has not been widely used for industry or research, and this is due to the fast hardening time of concrete. Therefore, it has the potential to be developed. High-quality concrete has a low cement water factor that causes low workability in concrete. Self-compacting geopolymer concrete (SCGC) has been developed as a high-quality concrete innovation with high workability. Concrete is produced by using gravel, sand, fly ash, alkaline activator, and water materials. This study used 14 Molar levels of NaOH. The variations used were 0%, 3%, 5%, and 7% superplasticizers (SP) made from polycarboxylate. This study used a dry mixing method to overcome the setting time on concrete. The results show that the workability that can be achieved is 645mm, and the compressive strength achieved is 41.7 Mpa
Environmental Effects of Sulphate on Conventional Concrete Based on Portland Composite Cement Yuyun Tajunnisa; Nur Achmad Husin; Sigit Darmawan; M. Faishal Darmawan; Suwandi Suwandi; Mitsuhiro Shigeishi
IPTEK The Journal of Engineering Vol 9, No 1 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v9i1.a16230

Abstract

Concrete performances have weaknesses; one of those weaknesses is that it is significantly affected when put in a high sulfate and chloride environment. This study aims to investigate sulfate's effect on PCC concrete's performance. In this research, PCC concrete was immersed in water for 28 days and conducted after the casting. After being soaked in water, three immersed specimens were removed and immersed in magnesium sulfate solution for 24 days and 84 days, whereas three others were removed and immersed in natrium sulfate solution for 24 days and 84 days. The observation showed that PCC concrete's average compressive strength test with water immersion was 42.17 Mpa. It meets the SNI 2847:2019 Indonesian standard for sulfate classification S1. The specimens decreased to 30.74 Mpa after being soaked in the magnesium sulfate solution for 28 days and again reduced to 25.39 Mpa at 84 days. The average compressive strength of specimens bathed in the sodium sulfate solution for 28 days was 32.19 Mpa. It decreased to 28.03 Mpa at the age of 84 days. The results of this study show that the compressive strength of PCC concrete soaked in sodium sulfate meets the SNI 2847:2019 standard for sulfate classification S1, which is more than 28 Mpa. The compressive strength of PCC concrete immersed in magnesium sulfate for 1 month (28 days) is more than 28 MPa. It meets the standard as well. Yet, the compressive strength of PCC concrete soaked in magnesium sulfate for 3 months (84 days) does not meet the standard.
Performance based design of Hospital Building in Surabaya under variety design alternative using SNI 1726-2019 – Case study: Redesign Building Sigit Darmawan; Raden Buyung Darmawan; Ridho Bayuaji; Yuyun Tajunnisa; Indra Komara; Sita Auliyah Rahmasari
IPTEK The Journal of Engineering Vol 9, No 2 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v9i2.a16231

Abstract

Nowadays, At the present time, the occurrence of regular earthquakes all over the world is turning into a significant problem. The structures that make up hospitals are among the most significant buildings in a living society because, in the event that a potentially dangerous scenario emerges, they help to serve as a caring and healing unit for the human population. A hospital building is made up of three different components: the structural component, the non-structural component, and the functional component. Each of these components can have an effect, either directly or indirectly, on the management and operation of the hospital building. Each time a natural or non-natural cause causes devastation and disaster, the globe suffers. In such cases, hospital buildings are vital in term of treating victims and injured persons, and housing those who lost their homes. Therefore, hospital facilities should be planned and constructed with enough stiffness and strength to resist disasters and serve as shelters or housing units afterward. This study analyses a hospital in area of Surabaya which built using Indonesian standard provision SNI 1726-2012. Weak structural members of the hospital are identified. The analysis determined to study the behaviour of hospital building when subjected to seismic forces using ETABS using current provision SNI 1726-2019. The investigation determined that the effect of the lateral forces under P-delta effect on the hospital building. Two different conditions have been compared, e.g., existing model and alternative configuration using dual system method to determining the recommendation for current building to resist seismic forces under new regulation. As a result, existing structure of hospital building still meet the requirements, but to fill the condition in accordance with SNI 1726-2019, some modifications need to be improved.
Workability Analysis of 3D Printing Materials for Applications in The Construction Industry Yuyun Tajunnisa; Ridho Bayuaji; Hendro Nurhadi; Beta Rahayuning Pratiwi
IPTEK The Journal of Engineering Vol 9, No 2 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v9i2.a16185

Abstract

The development of 3D Printing machine technology as a printing tool that uses an additive manufacturing method system with the aim of producing a three-dimensional (3D) object or object according to the default digital design file. 3D Printing was created to facilitate construction work, with 3D Printing construction work becoming lighter because this tool saves time, and costs, and reduces the risk of work accidents. With 3D Printing, work runs quickly and avoids problems in the development process. In the last few decades, many developed countries have used 3D Printing technology in making buildings. The 3D printing process basically consists of three different stages namely, data preparation, material preparation and transfer to the printer, and the printing stage. In the data preparation stage, the components are designed as 3D CAD models, then converted to STL (Stereolithography) format and sliced with the desired layer depth. The preparation of concrete involves mixing and placing it into a container. Once fresh concrete has been placed into the container, it can be channeled smoothly through a pump-pipe-nozzle system to print self-compacting concrete filaments, which build structural components layer by layer. The material used in this 3D printing method was Portland cement where this cement is easy to find among the public. Portland cement itself is the cement that is commonly used as a basic material for making concrete, plaster, mortar, and non-specialized mortar. In addition, fly ash and silica fumes are also added as a mixture. The addition of silica fumes increases the compressive strength of concrete. Furthermore, the addition of fly ash to the concrete has the effect of reducing drying shrinkage; but reducing the compressive strength of the concrete. In this study, the author focuses on the workability of 3D Printing concrete materials, and the impact of the material was added with additional type C fly ash and silica fume, namely flowability. The result is a concrete mix design that has good flowability value to be applied to the 3D Printing method
Performance of High-Damping Rubber Bearings for Seismic Isolation – Case Study of Nayumi Sam Tower Malang Apartment Ibnu Pudji Raharjo; Yuyun Tajunnisa; Indra Komara; Geralda Nurry Arifa; Sungkono Sungkono; Dicky Imam Wahyudi
IPTEK The Journal of Engineering Vol 9, No 3 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v9i3.a16233

Abstract

The base-isolation system is a highly effective earthquake-resistance technique. Especially when the building is under soft soil, however, it is detrimental to the horizontal displacement control of the isolation layer and less effective in decreasing the seismic response of the superstructure. Rubber bearings with high damping can produce substantial hysteretic damping and exhibit a hardening effect at high-shear strains. The research investigates the Nayumi Sam Tower Malang apartment as a case study with 10 stories of reinforced concrete with a double system structure which is in a soft soil location. High-damping rubber bearings (HDRBs) is used as a parameter study to understand the alteration and give a recommendation. The seismic response of the building is evaluated, and the HRDB alternative systems is confirmed using ETABS. It is pointed out that the HRDBs system can reduce the impact of earthquakes by close to 25% with the smallest section of structural dimension. According to new regulation building in Indonesia, the precise values of test circumstances, such as compressive force, shear displacement, and frequency, are developed. The findings are thoroughly discussed, the applicability of HRDBs for seismic isolation of residential buildings is concluded. Building with HRDBs isolation implied to have lower base shear and inter-storey drift which improved the performance of the structure with less damage.  
Rheology Analysis of 3D Printed Geopolymer Based on High Calcium Fly Ash Tajunnisa, Yuyun; Arrafid, Rifqi Nadhif; Bayuaji, Ridho; Nurhadi, Hendro
IPTEK The Journal of Engineering Vol 10, No 3 (2024)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v10i3.a21071

Abstract

The advancement of 3D concrete printing has focused on automation research in recent decades. 3D printing technology is adequate to reduce waste and improve efficiency for construction. Former research on 3D concrete printing used hydration cement based on ordinary Portland cement (OPC), which was not environmentally friendly. An alternative material to overcome problems with hydrated cement mortar is a geopolymer. Geopolymer mortar based on 3D printing is still in its infancy. Mechanical and rheological properties are the key parameters of this technology: yield stress, shear stress, and viscosity. The flow characteristics of 3D concrete printing represented the ability of material transfer along the system of the 3D printing machine. This research utilizes type C fly ash waste as the primary material for making geopolymer 3D-printed concrete. Variations of 8, 10, and 12 M of NaOH concentration were used to investigate the relationship between workability and quality of the geopolymer mortar. Workability testing of 3D concrete printing consists of several parameters: pumpability, extrudability, and buildability. Material identification, including rheology and flowability, is carried out to determine mortar specimens' pumpability, extrudability, and buildability. Several test approaches, such as slump flow, slump, shape retention, and rheometer tests using the vane shear approach method, were conducted to identify the rheological characteristics and flowability of the material. Based on testing of the material's workability, 10 M NaOH concentration variation is the most suitable material for future 3D printing material. The workability of 10 M NaOH is 177.5 mm and the the copressive strength is 25.84 Mpa. This variation meet ACI 318/318R – 14 criterion for building structure.
Compressive Strength Performance of High-Volume Fly Ash Concrete with CaCO3 Addition Wibowo, Yosi Noviari; Tatas, Tatas; Tajunnisa, Yuyun; Mawardi, Amalia Firdaus; Zanah, Miftaqul
IPTEK The Journal of Engineering Vol 11, No 1 (2025)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23378557.v11i1.a22092

Abstract

 This study investigates the compressive strength performance of High-Volume Fly Ash (HVFA) concrete with added CaCO₃ as a sustainable alternative to Ordinary Portland Cement (OPC) for infrastructure applications. The experimental research replaces a significant portion of cement with fly ash—a byproduct of coal combustion—aiming to reduce greenhouse gas emissions associated with concrete production. Two HVFA concrete mixtures were developed, substituting 37% and 47% of cement content with fly ash and adding 3% CaCO₃ to enhance mechanical properties. Material characterization, including XRF and XRD analysis, confirmed the suitability of fly ash for concrete production based on ASTM C618-19 standards. Aggregate gradation, moisture content, and specific gravity tests were conducted to optimize the mix design. Compressive strength tests were performed at 7, 14, and 28 days, showing that HVFA concrete with 37% fly ash substitution achieved higher strength values, reaching 25.92 MPa at 28 days, compared to the 47% mix, which reached 24.68 MPa. Slump tests indicated sufficient workability, with a measured slump of 10 cm for FA37C3 and 12 for FA47C3. These findings suggest that HVFA concrete with moderate fly ash substitution, complemented by CaCO₃ addition, can achieve compressive strength and workability comparable to OPC, supporting the development of environmentally friendly concrete solutions.    
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.
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