2031 research outputs found
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Contribution of Acacia mangium Root Systems to Slope Stability Improvement
No full textThis study explores the bioengineering potential of Acacia mangium root systems in enhancing the shear strength of lateritic soil under both saturated and unsaturated conditions. Seedlings were cultivated in cylindrical containers for 12 months to monitor root growth and investigate its relationship with key geotechnical parameters. Root development was classified into three distinct phases: root acceleration (months 1–3), stem acceleration (months 4–8), and growth phase (months 9–12). A significant dry root biomass increase was observed, exhibiting a strong linear correlation with peak shear strength. Laboratory shear tests indicated that unreinforced soil in saturated conditions had a cohesion of 1.90 kPa and an internal friction angle of 27.64°. In contrast, cohesion increased to 3.55 kPa in unsaturated conditions and the internal friction angle to 38.94°. In comparison, root-reinforced soils demonstrated substantially improved shear strength. Under unsaturated conditions, cohesion and internal friction angle reached 9.92 kPa and 41.58°, respectively, while in saturated conditions, values increased to 6.12 kPa and 31.29°. Slope stability analysis using Slope/W software revealed that the unreinforced slope had a Factor of Safety (FS) of 1.043, indicating marginal stability. However, with A. mangium root reinforcement, the FS increased to 1.518, exceeding the commonly accepted safety threshold of 1.5. These results highlight the effectiveness of A. mangium root systems in improving slope stability through mechanical reinforcement, increased soil cohesion, and redistribution of shear stresses within the soil matrix
Mechanical Properties and Structural Behavior of Sustainable Ferrock Concrete for Green Construction Applications
No full textThis study aims to develop a sustainable alternative to Ordinary Portland Cement (OPC) by investigating the mechanical and structural properties of Ferrock concrete, an iron carbonate-based binder composed largely of industrial by-products. An experimental program was conducted, testing over 114 concrete cubes, 18 cylinders, and 6 full-scale reinforced concrete beams with Ferrock replacing OPC at 5%, 10%, 15%, 20%, and 25% by weight. The results demonstrate that a 15% replacement ratio yields a 25% increase in 28-day compressive strength, while splitting tensile strength improves consistently with Ferrock content. Most notably, reinforced beams with 20% Ferrock exhibited up to a 33% increase in flexural capacity, with failure modes shifting toward more ductile behavior and experimental capacities exceeding predictions from ACI 318, CSA A23.3, and Eurocode 2 by up to 62%. This research confirms that Ferrock is not only a carbon-negative material but also a technically superior partial replacement for OPC, offering enhanced strength, ductility, and structural performance for green construction applications
Shear Behavior of Small-Scale Continuous Hidden Beams Using Tied and Spiral Stirrups
No full textHidden beams in reinforced concrete (RC) structures are widely used to meet architectural requirements; however, their reduced effective depth limits shear capacity. This study investigates the shear behavior of hidden beams reinforced with innovative rectangular staggered continuous spiral stirrups, addressing the absence of design guidelines for such reinforcement systems. Nine one-eighth-scale continuous beams were tested under two-point loading, with mortar used to reduce scale effects. The influence of the number, geometry, and configuration of spiral reinforcement was investigated. Both conventional and spiral stirrups significantly improved shear performance compared to the reference beam without transverse reinforcement (HB9-No). Beams with normal stirrups (HB1-N20, HB2-N30, HB3-N40, HB4-N50) increased shear capacity by 115%, 82%, 23%, and 4%, while spiral stirrup beams (HB1-S20, HB2-S30, HB3-S40, HB4-S50) achieved corresponding increases of 174%, 144%, 73%, and 27%, respectively. Overall, spiral reinforcement enhanced shear capacity and energy dissipation by approximately 30% and 46%, respectively, compared with conventional stirrups. Prototype capacities estimated using scaling relationships were compared with international design codes, which were found to be conservative. The findings demonstrate the effectiveness of spiral stirrups in improving shear strength and ductility and emphasize the need to include their contribution in future shear design equations for hidden beams
Optimization of Drilling and Blasting Parameters During the Drifting of Underground Mine Workings
No full textThe study aims to scientifically substantiate optimal drilling-and-blasting (D&B) parameters for driving underground mine workings under complex geological and mining conditions at the Akzhal deposit. The work addresses the selection of explosive types and the rational depth, configuration, and design of cut boreholes, together with their blasting pattern (BP), to improve rock-mass stability, operational safety, and advance efficiency. The methodology combines an assessment of geological-technical conditions with a review of current blasting practice, mathematical and numerical modelling of blast-induced face breakage, and pilot-scale industrial trials supported by statistical analysis and techno-economic evaluation under routine production constraints and reporting. The results show that optimization of the BP increases the borehole utilization factor (BUF) from η = 0.85 to η = 0.98. The locally produced Granulite A6 is proven effective, reducing blasting costs by 1.5 times relative to AS-8 while preserving the required energy characteristics. Charge optimization improves excavation-contour quality, enhances fragmentation uniformity, and reduces overbreak; the most rational solution is a rhombic cut combined with Granulite A6. Scientific novelty lies in integrating geological-geomechanical analysis, 3D modelling in Micromine, and industrial validation. Practical relevance is confirmed by decreasing cycle costs from USD 538.85 to USD 489.38, improving BUF, and enhancing contour quality
Evaluating Rainfall Effects on Soil Parameters and Slope Stability Using Hydrology Procedure (HP26)
No full textRainfall-induced slope failures are a major geohazard in tropical regions, often triggered by intense or prolonged rainfall that alters soil strength and pore water pressure conditions. This study evaluates the effects of rainfall duration on slope stability in Kota Belud and Ranau, Sabah, by applying Hydrology Procedure 26 (HP26) rainfall data with numerical modelling using SEEP/W and SLOPE/W under the Limit Equilibrium Method (LEM). Soil parameters were derived from site investigations, with strength values including cohesion (0.5-9.7 kPa) and friction angle (25.7°-30°). The results showed that short-duration rainfall (1 hour) had minimal impact on stability, while prolonged (24-hour) rainfall significantly increased pore water pressure, reducing the factor of safety (FOS) by 25-30%. A localized weak zone in Ranau was identified, with cohesion decreasing from 7 kPa to 5 kPa between 7.4 m and 13.5 m depth, corresponding to potential slip surfaces. Findings align with previous research on infiltration-driven failures, but this study demonstrates the practical use of HP26 rainfall design data for tropical slope analysis. The novelty lies in linking rainfall duration, soil-water interactions, and FOS reduction through a standardized rainfall procedure, providing a framework for improved slope risk assessment in rainfall-prone terrains
Functional Verification of a Stainless Steel Reference Block for Calibration of Industrial Ultrasonic Test System
No full textIn the construction and assembly of metal structures, ultrasonic testing constitutes a pillar for the guarantee of structural integrity. This study aimed to develop and experimentally validate a semi-cylindrical reference block, optimized for the ultrasonic inspection of welds in austenitic stainless steels under the AWS D1.6 code. Unlike conventional devices, this proposal integrates three functional zones into a unified body. Methodologically, the acoustic properties of velocity and attenuation coefficient were characterized using the pulse-echo technique with 2.25 and 5.0 MHz transducers, validating the results through analysis of variance (ANOVA) and Pearson correlation. The findings revealed a statistically significant influence of frequency on the acoustic properties of the material. Functionally, experimental tests demonstrated that the geometric arrangement of three integrated references allows for the efficient construction of Distance-Amplitude Correction (DAC) curves and direct angular verification, overcoming the logistical limitations of conventional prismatic blocks. The main novelty of the device lies in its capacity to unify the functions of sensitivity, resolution, and distance calibration into a single body of acoustically equivalent material, eliminating the need for complex correction factors and ensuring greater precision in industrial inspection
Development of Fiber-Reinforced Concrete for Road Pavement Surfaces Enhanced with Complex Additives
No full textThis study aims to develop high-performance road pavement concrete capable of withstanding increasing traffic loads while ensuring long service life and reduced maintenance needs. The research focuses on enhancing the mechanical characteristics of fine-grained concrete used in the outer pavement layer through the incorporation of complex additives and dispersed reinforcement. The methodology involved modifying the concrete matrix using the superplasticizer Melflux 5581F, microsilica MK-85, and varying percentages of basalt fibers introduced through different preparation techniques. Mechanical testing, including compressive and flexural strength evaluations, was performed on 40×40×160 mm specimens cured under standard conditions and tested at 7 and 28 days. The analysis showed that Melflux 5581F significantly enhanced strength without increasing cement content, while MK-85 further improved compressive and flexural strengths by up to 50.59% and 46.28%, respectively. The addition of basalt fibers increased flexural strength, with optimal formulations achieving 89.49 MPa in compressive strength and 11.14 MPa in flexural strength. These findings demonstrate that the combined use of chemical, mineral, and fiber additives, together with appropriate technological approaches, substantially improves the performance of road concrete. The proposed modified concrete exhibits enhanced durability, offering a promising solution for extending pavement service life and reducing repair frequency
An Automated Framework for Benthic Habitat Classification and Segmentation Based on Deep Learning Algorithms
No full textAlthough benthic habitats represent some of the largest, most diverse, and productive ecosystems on Earth with great environmental, and economical value, they are increasingly threatened and declining in many locations worldwide. Every year, numerous underwater images are collected for monitoring these habitats. Still, the manual labelling process remains tedious and time-consuming, creating a huge gap between data collection and extraction of meaningful information. In this study, an automated framework is proposed for single-label classification and semantic segmentation of benthic habitats using convolutional neural networks (CNNs). The framework integrates and evaluates various pre-trained CNNs, bagging of features (BOF), color spaces, and texture descriptors for benthic habitat classification. Furthermore, the classified images served as training and validation samples to assess the semantic segmentation performance of pre-trained CNNs with different architectures (e.g., ResNet-50, AlexNet, Xception, etc.). Both high- and low-quality underwater images of benthic habitats collected from six diverse study areas located off Australia and Japan were used to evaluate the proposed framework. The analysis revealed that the ResNet-50 FC1000 combined with BOF, color space, and texture attributes yielded the highest automatic classification accuracy. Moreover, the ResNet-50 network outperformed all the tested networks for automatic semantic segmentation of benthic habitats. Overall, the presented framework enhanced the automation of benthic habitat classification and semantic segmentation processes
Stakeholder-Based Risk Analysis in Post-Disaster Housing Projects: Toward Improved Risk Management Practices
No full textReconstructing housing after a disaster is a demanding and intricate process, particularly when managing risks that affect project delivery timelines. The community-based approach, widely adopted in Indonesia, seeks to foster local participation but is often hindered by implementation challenges. This study aims to identify and analyse the critical risks contributing to delays in community-driven housing reconstruction projects in Pidie Jaya Regency, Aceh, Indonesia, as perceived by stakeholders. Research variables were developed sequentially through a literature review, semi-structured interviews, focus group discussions (FGDs), and questionnaires. A mixed-methods approach was employed, combining thematic analysis with descriptive statistics and indices, such as the frequency index (FI), severity index (SI), and risk importance index (RII). Seventy-one risk variables were identified, including 17 newly documented risks not previously addressed in the literature. Three variables were found to be particularly significant: shortage of facilitators, limited labour availability, and insufficient community construction skills. The findings contribute theoretically by broadening the understanding of operational risks during the construction phase and offer practical guidance for policymakers in developing more effective mitigation strategies, with implications for other developing nations utilising community-based reconstruction
Numerical Investigation of Oil Shale in Asphalt for Road Surfacing Using COMSOL Multiphysics
No full textThis study introduces a sustainable, performance-driven approach to asphalt pavement design by incorporating oil shale-modified bitumen into hot-mix asphalt (HMA) and evaluating four performance grade (PG) binders. The research provides a comprehensive evaluation of mechanical and rheological behaviors across varying thermal and loading conditions. A key innovation lies in the integration of oil shale, which significantly reduces voids in mineral aggregates (VMA), leading to improved aggregate contact and material densification. This microstructural enhancement directly translates into increased dynamic modulus (E*) and shear modulus (G*), reinforcing the mixture’s stiffness and deformation resistance without the need for costly chemical additives. The results demonstrate that oil shale improves the load-bearing capacity of asphalt mixtures, particularly under high-frequency loading where elastic responses are favored. Moreover, the optimized mixtures maintain a favorable balance between rigidity and flexibility, typically prone to compressive deformation, and benefit from oil shale integration through enhanced stress dissipation characteristics. The study offers a novel pathway for valorizing oil shale, a locally abundant, underutilized material, as a functional asphalt modifier. The findings validate its potential to extend pavement service life, optimize stiffness–temperature profiles, and reduce dependency on virgin bitumen. These results position oil shale as a viable, cost-effective, and environmentally advantageous additive for future-proof pavement engineering