IJIMCE : International Journal of Innovation in Mechanical Construction and Energy

Conversion of Waste Tyres into High-Energy Fuel Products Using Pyrolysis Technology

Hyginus Unegbu — 2025-11-30

The accumulation of waste tyres poses a critical environmental and public health concern due to their non-biodegradability, complex composition, and fire hazard potential. This study explores the thermochemical valorization of end-of-life tyres into high-energy fuel products through pyrolysis, emphasizing process optimization, product quality assessment, and environmental performance. A fixed-bed pyrolysis system was operated across a temperature range of 350°C to 550°C to evaluate its influence on product distribution and yield characteristics. The maximum oil yield of 52.3% was obtained at 500°C, representing the optimal balance between primary depolymerization and suppression of secondary cracking reactions. The pyrolysis oil exhibited a high heating value (43.6 MJ/kg), suitable for energy applications, but exceeded international standards for sulfur content and viscosity, necessitating upgrading prior to use in transportation fuels. The gaseous fraction, enriched with hydrogen and light hydrocarbons, showed strong potential for process self-sufficiency and co-generation. Solid char demonstrated favorable physicochemical properties for application as a fuel or adsorbent material. Statistical modeling using linear regression accurately predicted oil yield trends, and Aspen Plus® simulations closely aligned with experimental results, validating the process model for scale-up. A comparative life cycle assessment revealed that pyrolysis significantly outperforms incineration in terms of greenhouse gas reduction, energy recovery, and particulate matter emissions. These findings confirm that tyre pyrolysis is a technically feasible and environmentally advantageous approach for sustainable waste management and fuel generation. Further integration with refining technologies and renewable energy inputs is recommended to enhance commercial viability.

Percentage Refusal Density (PRD) Performance of Hot Rolled Sheet-Wearing Course (HRS-WC) Mixture with Substitution of Palm Shell Ash as Filler

Lusyana — 2025-11-30

The increasing traffic volume and excessive loads on road pavements often cause permanent deformation in the wearing course layer. One potential solution is the utilization of industrial by-products, such as palm shell ash, as an alternative filler in Hot Rolled Sheet-Wearing Course (HRS-WC) mixtures. This study aims to evaluate the effect of palm shell ash substitution on the Optimum Asphalt Content (OAC) using the Marshall method and the Percentage Refusal Density (PRD) approach. The research was conducted through laboratory experiments with substitution variations of 0%, 25%, 50%, 75%, and 100%. The results indicate that the OAC determined by the Marshall method tends to increase with higher palm shell ash content, ranging from 7.46% to 8.30%. Meanwhile, the OAC values based on PRD range between 7.29% and 8.13%, with the 50% substitution producing the most optimal value at 7.29%. These findings suggest that palm shell ash has significant potential as an eco-friendly alternative filler to enhance the performance of HRS-WC mixtures while simultaneously promoting sustainable utilization of palm oil industry waste

Tensile Strength Test of SMAW Welded Joints on ASTM A36 Steel With Cooling Media Variations Water, SAE 10W- 40 oil, and Air

Tiara Putri — 2025-11-28

Welding is one of the essential processes in the manufacturing industry. One of the factors that affects the quality of welding results is the cooling medium used after the welding process. This study aims to determine the effect of different cooling media on the tensile strength of SMAW (Shielded Metal Arc Welding) welded joints on ASTM A36 steel. Three types of cooling media were used air, water with a pH of 6.5–8.5 and SAE 10W-40 oil. The welding process was carried out using an I-groove with a butt joint in the 1G position, using an E7018 electrode with a diameter of 3.2 mm and a current of 100 A. The tensile tests were conducted according to the ASTM E8 standard.The results showed that the specimens cooled with SAE 10W-40 oil produced the highest average tensile strength of 574.9974 Mega pascal and the highest average elongation of 38.73%. Cooling with water resulted in an average tensile strength of 566.5932 Mega pascal and a maximum elongation of 28.27%. Meanwhile, cooling with air resulted in the lowest average tensile strength of 545.5592 Mega pascal and an elongation of 30%. The highest modulus of elasticity was obtained from water cooling at 2051.55 Mega pascal, followed by air at 2048.60 Mega pascal, and the lowest was from oil at 1493.83 Mega pascal.Based on these results, it can be concluded that the variation of cooling media affects the tensile strength of welded joints. Cooling with SAE 10W-40 oil provided the most optimal results, producing the highest tensile strength and good ductility. Therefore, SAE 10W-40 oil is recommended as the best cooling medium for the SMAW welding process on ASTM A36 steel, especially in ship hull applications.

Keywords: SMAW, ASTM A36 Steel, cooling media, tensile strength, I-groove, butt joint, ship hull.

The Effect of Using Palm Shell Fly Ash with Crushed Fine Aggregate on the Compressive Strength of Concrete

Zulfira Mirani — 2025-11-30

Palm shell combustion waste produces fly ash containing chemical elements such as silica (SiO2) and aluminum oxide (Al2O3), which can act as pozzolanic material. Pozzolans are materials containing silica (SiO2) and aluminum oxide (Al2O3) that cannot harden or bind independently like cement when mixed with water, but can react with calcium hydroxide Ca(OH)2 produced from the hydration process of cement, forming cementitious compounds. This study aims to determine the effect of palm shell fly ash as a substitution material and additive on the compressive strength of concrete with crushed fine aggregate variation. The tests were conducted with fly ash content of 0%, 15%, 17.5%, 20%, 22.5%, and 25% of cement weight. All specimens were cured under standard conditions and tested at 28 days. The results showed that, with crushed fine aggregate, the compressive strength of concrete with 20% fly ash substitution reached 30.848 MPa, which is 39.15% higher than concrete with fly ash as additive (22.169 MPa). From an engineering standpoint, the optimal substitution level of 20% fly ash yields the highest compressive strength with crushed fine aggregate, providing valuable insight for practical mix design optimization. Although the compressive strength did not exceed that of plain concrete in all conditions, the performance improvement at certain substitution levels highlights the potential for fly ash to enhance durability, workability, and long-term strength development due to its pozzolanic reaction. However, compared with plain concrete without fly ash (24.166 MPa), the addition or substitution of fly ash did not result in higher strength overall. The findings of this study have several important implications for sustainable construction materials and the broader field of concrete technology. The utilization of palm shell fly ash as a partial cement replacement demonstrates the potential for converting agricultural waste into value-added construction materials. This supports environmental sustainability by reducing cement consumption, which is a major source of CO2 emissions, and by minimizing waste disposal problems from palm oil industries.

Physics-Informed Neural Networks for Predictive Maintenance in Nigerian Hydropower Infrastructure

Hyginus Unegbu — 2025-11-30

Ensuring the operational integrity of hydropower infrastructure is critical for maintaining energy security and grid stability in Nigeria. However, conventional predictive maintenance frameworks are hindered by inconsistent data availability, poor sensor coverage, and a lack of physical interpretability. This study presents a robust Physics-Informed Neural Network (PINN) architecture tailored for predictive maintenance in Nigerian hydropower systems. By embedding domain-specific physical laws—namely Bernoulli’s principle, the turbine power equation, and Fourier’s law of heat conduction—directly into the model’s loss function, the proposed PINN integrates physical reasoning with deep learning to produce accurate and explainable degradation forecasts. Simulated operational data reflective of real-world hydropower conditions were used to train and evaluate the model. Comparative analysis against Long Short-Term Memory (LSTM) networks and Random Forest (RF) regressors demonstrated the superior performance of the PINN, which achieved an RMSE of 4.75 days and an R² value of 0.88. Furthermore, physics residuals across all governing constraints were consistently below 0.04, indicating strong physical consistency. The model accurately predicted failure in three fault scenarios—runner blade erosion, stator insulation decay, and penstock pressure surges—with lead times ranging from 7.5 to 11 days, thereby enabling actionable intervention before catastrophic breakdown. A real-time monitoring interface was developed to visualize model outputs, risk thresholds, and residual dynamics, facilitating operator trust and integration into existing maintenance workflows. This research establishes the PINN as a scalable and domain-aware solution, well-suited for advancing predictive maintenance capabilities in Nigeria’s evolving hydropower infrastructure.

Optimization of a Two-Stroke Gasoline Grass Cutter into a Rice Harvesting Machine

Muhammad Zam Zami Koto — 2025-11-30

In Indonesia, rice harvesting in rural areas is still largely done manually, resulting in low efficiency and high labor demands. This study aims to provide a practical solution by optimizing a two-stroke gasoline-powered grass cutter into a functional rice harvester. The research was conducted through stages including literature study, problem identification, design, fabrication, and performance testing. Mechanical analysis shows that the modified machine produces 47.7 N·mm³ torque and a cutting speed of 40.05 m/min, adequate for cutting rice stalks without stalling. Fuel tests revealed Pertamax offers better combustion efficiency than Pertalite. The balancing system improves operator comfort, while field trials showed a reduction in harvesting time by over 55% and labor costs by 50%. These results indicate that the optimized machine is effective, low-cost, and suitable for smallholder farmers.

Analysis of the Effect of Using Marlstone Filler on Road Pavement (AC-WC) on Marshall Values

Roza Mildawati — 2025-11-30

The materials commonly used as fillers in AC-WC road pavement mixtures are cement and fly ash, which are relatively expensive and in limited supply. Therefore, research is needed to use alternative materials as filler substitutes. One of the alternative materials is marlstone, which contains chemical compounds in the form of CaCO3. The purpose of this study was to determine the effect of marlstone in AC-WC mixtures on the Marshall value. The percentage variations of marlstone utilization as filler substitutes were 0%, 25%, 50%, 75%, and 100% of the total weight of the fly ash filler. This study used the Marshall test method which refers to the 2018 Bina Marga Specifications, Revision 2. In this study, the optimum asphalt content was 5.4%. The greater the percentage of filler used in the mixture, the VMA and VIM values increased, however, for the VFA parameter at variations of 0%, 25%, and 100% that met the 2018 Bina Marga Specifications, Revision 2. The stability values for the percentage of marl stone as a filler substitute ranging from the smallest to the largest were 2422.1 kg, 2396.195 kg, 2180.321 kg, 2167.369 kg and 1826.289 kg. Although there was a decrease in stability, it still met the established standards. The flow value in this study decreased and increased, but was still within the specification standards. In this study, the variation using marl stone filler did not meet the minimum requirements of the 2018 Bina Marga Specifications, Revision 2.

Design and Implementation of an HMI-Based Monitoring System for Automatic Water Purification

Dedi Erawadi — 2025-11-30

Water is one of the basic things in human life, even every living thing needs water to survive. But in reality, there are many villages in Indonesia that experience environmental problems, one of which is water pollution. Lack of clean water is a problem in this research. This research aims to find out the design and development of an automatic water purification system based on PLC and HMI, find out how to increase the efficiency of the water purification process through automation, and provide a user interface for monitoring and control of the system. This research method uses the discussion method, literature method, and observation method. Program testing on PLC and HMI-based water purification equipment is using the CX Programmer program and visualization on the CX designer. By using CX Programmer and CX Designer assisted by other PLC and HMI tools or systems, the water purification system can be controlled and monitored automatically. The water purification system can improve the efficiency of the water purification process through the development of CX Programmer and CX Designer programs such as program performance monitoring, process control, data review, analysis and inspection of the system. Integrating CX Programmer and CX Designer through the same observation of each CX Designer object with the instructions in the CX Programmer program created and can involve between CX Designer software installed on a laptop for PL.