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Cluster-Driven Predictive Model for Asphalt Pavement Maximum Temperature in Tropical Airport
No full textThe majority of runways are constructed using flexible pavement surfaced with Hot Mix Asphalt (HMA). The performance of these materials is significantly influenced by temperature due to their viscoelastic nature. Understanding the maximum temperature profile in the HMA layer is essential for evaluating pavement load-bearing capacity and durability. Therefore, this study aimed to present a robust model for predicting maximum pavement temperature distributions based on direct measurements from 13 strategically selected airports in the tropical region of Indonesia. Data was collected using the Airside Pavement Sensing System (AirPaSS), a monitoring device that integrated solar-powered energy management, automated data transmission, and multi-depth thermocouple sensors, providing real-time and accurate temperature measurements. By using hierarchical clustering, airports were categorized into three clusters based on air temperature, pavement temperature, and elevation, enabling precise and cluster-specific material design. The result showed that the predictive model incorporating linear and logarithmic regression achieved high accuracy, with Root Mean Squared Error (RMSE) values ranging from 0.91°C to 2.01°C and Adjusted R² values between 0.76-0.91. This model offered a practical solution for predicting HMA layer temperature at any depth. The results provided valuable information for performance-based grading systems with significant implications for improving infrastructure resilience in tropical and similar climatic regions. Doi: 10.28991/CEJ-2025-011-03-01 Full Text: PD
Assessing Sediment Transport and Shoreline Dynamics in High-Energy Tropical Coasts
No full textThis research examines coastal erosion in North Galesong, Indonesia, by validating longshore sediment transport (LST) equations and predicting shoreline changes over ten years. To evaluate sediment movement and coastline alterations, it integrates field data on sediment grain size and wave characteristics with numerical modeling techniques, including the CERC equation and finite difference methods. Sieve analysis revealed a range of sediment textures (D50: 0.17–0.65 mm), predominantly medium-fine sand. Wave analysis indicated a dominance of moderate energy southwesterly waves (1.5 m height, 6.39 s period) that aid sediment transport. The empirical LST models, calibrated with local data, closely matched numerical simulations (error <20%), predicting an annual net northward sediment transport of 406,869 m³. Shoreline analysis across 15 segments showed significant spatial variability: severe erosion occurred in Cell 4 (Δy = -0.82 m), while Cell 3 saw accretion (Δy = +0.68 m), influenced by wave direction, sediment supply, and coastal morphology. This study underscores the value of hybrid empirical-numerical methods in data-scarce regions and emphasizes the need for local model calibration to enhance coastal resilience. The findings inform sustainable management practices, promoting adaptive strategies to address sediment imbalances and hydrodynamic changes due to climate factors
An Automated Assessment Technique for Pavement Defects Using a Laser Scanner and Deep Machine Learning
No full textRoads are vital arteries and main links between and within cities. They are considered the main auxiliary factor in shortening travel time and achieving users' comfort and safety. Governments strive to provide ideal conditions on the roads to achieve the highest levels of satisfaction, which are reflected in the quality of rides provided. Despite the variety of monitoring and evaluation methods, achieving the best and most accurate diagnosis of the condition of the roads and determining the severity of defects and appropriate and rapid maintenance methods are still lacking. This study aims to monitor and evaluate the state of some roads in Aswan City, Egypt, to identify defects and address them promptly. To achieve this goal, a laser scanner was used to evaluate pavement conditions by measuring the coordinates of the road surface and determining the differences in the measured values on the three axes. A built-in camera was also used in the laser device to monitor the type and severity of defects and match them with the measurements of the laser scanner device. Finally, a deep machine learning system, including LSTM, GRU, RF, SVM, and DT, was used to identify and classify the type and severity of defects. The prediction models showed significant accuracy with about 93%, 91%, 85%, 84%, and 82%, respectively. Doi: 10.28991/CEJ-2025-011-03-015 Full Text: PD
An Assessment of Nature-Based Solutions Water Infrastructure for Flood Risk Reduction in Unplanned Area
No full textThis study aimed to investigate the effectiveness of the Brigif Reservoir as a pioneering nature-based infrastructure solution for mitigating flood risk in the Kemang area, a significant business district in South Jakarta, and to provide a potential raw water supply for city parks. We employed coupled HEC-HMS and HEC-RAS 1D2D unsteady flow models to analyze rainfall-runoff and flood regimes before and after basin intervention in a rainfall scenario from January 2020. The flood model demonstrated highly satisfactory performance on the calibration results, as evidenced by an NSE value of 0.93 on a scale of 0 to 1. Flood risk was defined using the flood hazard, vulnerability, and capacity indices, and ArcGIS and QGIS were used to prepare and visualize the output after the model performance was qualified. The study revealed that the Brigif Reservoir could reduce the peak discharge of the January 2020 flood in the Kemang area by 19% while decreasing the risk of high-level flooding by 12%. The Brigif Reservoir, as a Nature-Based Solution (NBS) infrastructure, retains approximately 250,000 m³ of flood discharge, which can be utilized by the local government for watering gardens and as potential raw water for residents because it meets the national surface water quality standards in dry conditions and requires additional treatment during the wet season. The potential for groundwater recharge was estimated to be approximately 250 m³ and 6000 m³ for one hour and one day, respectively. For future studies, it is recommended to develop non-structural actions, such as a flood early warning system incorporating machine learning that could potentially support the operational performance of the NBS infrastructure. This study proposes the implementation of a series of sustainable infrastructure solutions, including rooftop storage, underground storage, and underground retention systems, at the building scale within each sub-catchment to mitigate flood risk levels in the Kemang region from high to acceptable levels. The findings of this research will be of significant value to the Water Resources Agency in evaluating the potential application of NBS infrastructure for flood mitigation and adaptation strategies and programs in response to the impacts of global climate change. Doi: 10.28991/CEJ-2025-011-05-07 Full Text: PD
Response of Long-term Cyclic Laterally Loaded Monopiles in Sand
No full textThe offshore wind energy industry has grown rapidly, with large-diameter monopiles becoming the primary foundation choice for offshore turbines. Monopile designs emphasize serviceability and fatigue limits, enforcing strict rotation limits set by manufacturers. These structures face considerable lateral cyclic loads from waves, currents, and wind. Existing design codes such as API and DNV GL are commonly used but do not sufficiently capture monopile behavior under cyclic loading, particularly regarding load cycle count, amplitude, and type. Moreover, the dynamic response of the monopile-soil system, which affects the foundation’s natural frequency, depends on the pile-soil interaction stiffness—an aspect neglected in current standards. This research reports results from seventeen 1-g cyclic loading experiments and six monotonic tests on monopiles installed in dry sand. Findings reveal that cyclic deformation is significantly influenced by sand relative density, load cycle number, and cyclic load characteristics (magnitude and type). Cyclic loading also alters the pile-soil stiffness. Accumulated rotation grows exponentially with increasing load cycles, while cyclic secant stiffness increases logarithmically. The study further identifies asymmetric two-way cyclic loading as the most damaging load pattern for monopile performance
Influence of Axial Restraint and Fire Exposure Scenarios on the Fire Resistance of One-Way Reinforced Concrete Slabs
No full textThis study investigates the behavior of one-way simply supported reinforced concrete slabs under fire conditions, focusing on the effects of axial restraint and fire exposure scenarios on their fire resistance. The slabs are subjected to standard ISO 834 fire exposure, and the nonlinear analysis is carried out via the SAFIR2016 computer program, which employs the finite element method. A comparison of the numerical results with experimental results from various studies has shown good agreement. To verify the reliability of the numerical results, it is essential that the test parameters match those used in the simulations. This study aims to evaluate the accuracy and reliability of fire safety regulations for designing one-way simply supported slabs and to identify potential discrepancies between design codes and numerical findings. A 3D analysis is performed, with discretization using shell elements. The results reveal that axial restraint significantly influences the fire resistance of slabs. When axially restrained and exposed to fire from the bottom, the slab achieves fire resistance exceeding ten hours. However, under the same boundary conditions, the fire resistance of the slab is 339 minutes if the fire acts from the top. Without axial restraint, the direction of fire exposure becomes critical. When the fire acts from the bottom, the primary reinforcement is exposed to high temperatures, causing the slab to lose stability as the resisting moment decreases than the acting moment. Conversely, when the fire acts from the top, the slab without axial restraint shows high fire resistance, as the reinforcement remains in the cooler zone, leading to a fire resistance greater than ten hours. Doi: 10.28991/CEJ-2025-011-04-03 Full Text: PD
Axial Compression Behavior of Concrete-Encased CFST Columns
No full textComposite construction known as concrete-encased CFST is an outer covering of concrete surrounding a steel tube filled with concrete. It is employed as a structural member in multi-story buildings, large structures, bridges, and underground subway systems. Most of the literature deals with steel tubes filled with core concrete or concrete-encased steel tubes filled with core concrete with main reinforcement, but in the present study, CFST is used as conventional reinforcement. Therefore, five concrete-encased CFST columns and one normal reinforced concrete column were loaded axially. Variables were effects of CFST, percentage of steel tubes, outer concrete compressive strength, compressive strength of steel tube concrete, and ratio of unfilled steel tubes. The experimental test result of the reference concrete-encased CFST ultimate axial compression strength showed 65.1% strength of a conventional column. An increase in the ratio of CFST from 6.8% to 10.2% enhanced ultimate axial compression by 19.2% compared to the reference concrete-encased CFST column. Furthermore, a rise in the outer compression strength of the outer concrete from 15 MPa to 20 MPa resulted in an increase of 14.94% in ultimate axially compression loads. An increase of concrete compression strength within the steel tubes from 35 MPa to 45 MPa resulted in a slight increase of 0.62% in the ultimate load. The 16.8% reduction in the ultimate load, however, was due to the presence of a hollow steel tube inside the concrete-filled CFST. The validated finite element model was therefore employed to examine the effect of different parameters that affect the concrete column using a parametric study
Revolutionizing Self-Healing Asphalt: Optimized Encapsulated Rejuvenators for Enhanced Durability and Sustainability
No full textIn an era where sustainable infrastructure is crucial, self-healing asphalt emerges as a transformative solution to enhance pavement longevity and reduce maintenance costs, addressing the global challenge of deteriorating road networks. This study presents a pioneering investigation into the development and performance evaluation of encapsulated rejuvenators for self-healing asphalt, utilizing two distinct compositions; waste cooking oil (WCO) and Fischer-Tropsch bright stock oil (FTBSO), across three capsule sizes (1 mm, 2 mm, and 3 mm). Through the experimental tests on compressive strength, thermal stability, and rupture resistance under wet conditions, the ongoing study highlights the critical influence of capsule size and composition on the mechanical performance, as well as the resistance to degradation and oxidation under similar asphalt production conditions, including applied stresses and temperatures. The findings indicate the superior performance of 3 mm FTBSO-based encapsulated rejuvenators, which exhibit exceptional compressive strength (155 N), minimal weight loss (2% at 200° C after 1-hour short-term aging), and high rupture resistance (80 minutes to break under moisture at 100° C), making these capsules ideal for withstanding mechanical and thermal stresses, while ensuring effective crack repair. In addition, both 2 mm and 3 mm FTBSO- and WCO-based rejuvenator capsules demonstrated high resistance to compressive stresses, excellent thermal stability, and strong rupture resistance, making these capsules suitable for self-healing asphalt applications. In contrast, 1 mm WCO-based rejuvenator capsules exhibited the lowest compressive strength (32 N), the highest weight loss (10% after 1 hour of short-term aging at 200° C), and the fastest rupture under moisture (18 minutes to break at 100° C), making these capsules the least suitable for self-healing asphalt applications
A Novel Steel Lazy Wave Riser Configuration for Ultra-Deepwater
No full textA steel lazy wave riser (SLWR) configuration combines buoyancy modules with a traditional steel catenary riser (SCR). The buoyancy section at the riser separates the floater's motion and acts as a damper toward the critical area in the touchdown point, improving the strength and fatigue performance. In ultra-deepwater environments, the substantial payload of risers due to extreme riser length imposes considerable tension and stress, challenging the limits of traditional configurations such as SLWR and SCR. The effective tension, maximum stress, and minimum bend radius at ultra-deep depths of these conventional risers would exceed the allowable limits, leading to potential structural failure. To address these limitations, this study proposes a novel riser configuration, the shaped steel lazy wave riser (SSLWR), specifically for ultra-deepwater conditions. By introducing an additional buoy section, SSLWR effectively reduces the effective tension while ensuring allowable stress distribution across the riser length, enhancing structural reliability and operational feasibility over traditional risers. OrcaFlex, a fully 3D non-linear finite element software widely used in maritime structure analysis, was used to simulate the effective tension, maximum stress, and minimum bend radius of the SCR, SLWR, and SSLWR configurations at 3000 m depth. The SSLWR shows a maximum effective tension that is less than half of that observed in the SCR, and it remains consistently lower than SCR and SLWR, suggesting that SSLWR holds promise as a robust alternative for ultra-deepwater applications. This study offers new insights into how modifying riser shape and buoy placement can effectively balance tension reduction with stress distribution, providing an alternative to traditional riser designs. The SSLWR's specific responses to buoy placements and varying currents expand an understanding of riser performance under varying conditions, guiding future advancements in offshore riser engineering. Doi: 10.28991/CEJ-2025-011-01-03 Full Text: PD
Modified Asphalt Mixtures Incorporating Pulverized Recycled Rubber and Recycled Asphalt Pavement
No full textIn the search to achieve eco-friendly techniques that ensure significant improvements in the properties of hot mix asphalt (HMA), recycled materials are being considered with greater application, coming from the pavement itself and also from artificial elements such as rubber. In this sense, the objective was to study the behavior of the mechanical and microstructural properties of HMA by adding pulverized recycled rubber (PRR) and recycled asphalt pavement (RAP), taking into account a control group without any addition and an experimental group with PRR and RAP. The research involved the production of briquettes with the modification of asphalt cement (AC) using doses of 3%, 5%, and 7% of PRR as a replacement by weight of AC. Then, the optimal percentage of PRR was combined with 10%, 20%, and 30% RAP as a partial substitute for the coarse aggregate. It should be noted that in both aspects, the thermogravimetric and microstructural performance of the asphalt mixture was evaluated. Subsequently, the results obtained indicate that the HMA is MAC-1 type, and it was established that the combinations of PRR and RAP significantly influence the physical-mechanical properties of the HMA with 3%PRR+10%RAP. On the other hand, the findings of the PRR thermogravimetric analysis show that the degradation of HMA occurs at 350°C, causing the loss of both mechanical and microstructural properties. However, infrared spectroscopy and scanning electron microscopy revealed that the PRR adheres correctly with the aggregate, improving the morphology and texture of the HMA. Doi: 10.28991/CEJ-2025-011-02-02 Full Text: PD