Journal of Science and Technology in Civil Engineering (JSTCE) - HUCE

Editorial Board — 2025-12-25

Optimization strategy of model B4TW-SCC in predicting shrinkage of self-compacting concrete

Nguyen Doan Binh — 2025-12-25

Shrinkage strain directly reduces the dimensions of concrete, leading to potential intrusion of deleterious substances into the structure, affecting the durability in the long term, especially self-compacting concrete (SCC), which differs from conventional concrete in its composition, featuring a higher paste content and a lower amount of coarse aggregate, and consequential reduction in restraining capacity of aggregate. Most available models were designed to estimate the shrinkage strain of conventional concrete and lack the efficient prediction models of SCC. The enhancement in predicting could be applied to minimize the drawback of shrinkage on the building quality by preventing cracks and surface defects. Therefore, the new model B4TW-SCC was adjusted from the model B4, encompassing composition and compressive strength, to closely fit the newly collected database comprising 1316 test curves of shrinkage, assembled from numerous published papers. The paper presented a detailed optimal process based on both the minimum error of statistical indicators and the weighting scheme of the database to determine the important factors of the model B4TW-SCC for predicting the shrinkage of SCC. The evaluation results indicated that the developed model exhibited the highest efficiency with NRMSE values of only 52.3% and 50.5% in estimating autogenous shrinkage and total shrinkage among the current models for conventional concrete of B4, fib, and ACI, as well as the models for SCC, including CEB90-SCC (Poppe) and JSCE-SCC (Aslani).

Effect of particle density on powder mixing in nuclear fuel pellet fabrication using discrete element method

Vu Duc Chung — 2025-12-25

Granular mixing is a fundamental operation in the fabrication of mixed-oxide (MOX) nuclear fuels, where achieving homogeneous blends of constituent materials is essential for reactor performance and safety. Using particle dynamics simulations, we investigate the flow behavior and binary mixing of equi-sized spherical particles with differing densities in horizontal rotating drums operating within the cascading regime. An extensive parametric study is conducted by systematically varying the particle density while keeping all other particle properties fixed. The simulation results indicate that mixtures composed of particles with similar densities undergo efficient mixing, whereas mixtures with large density contrasts exhibit persistent segregation. In the latter case, denser particles are concentrated near the drum core, while lighter particles settle away from the core. Additionally, the curvature of the free surface is observed to increase monotonically with the particle density ratio, indicating a strong coupling between density-driven segregation and surface flow dynamics. These findings provide insights into the mechanisms governing density segregation in rotating drums and have implications for optimizing mixing processes in industrial and nuclear fuel fabrications contexts.

Static bending and buckling analyses of GPL-FGM microplates placed on Winkler-Pasternak elastic foundation

Jaroon Rungamornrat — 2025-12-25

In this article, the static bending and buckling behaviors of microplates resting on a Winkler-Pasternak elastic foundation is studied. The microplate model is composed of metal-ceramic functionally graded material (FGM) reinforced by graphene nanoplatelets (GPLs), forming a GPL-FGM microplate. The FGM matrix properties vary according to the power-law distribution model, whereas the GPLs are distributed following five patterns (D1, D2, D3, D4 and D5) across the thickness. The governing equations for static bending and buckling analyses of the microplate model are derived utilizing the modified couple stress theory (MCST), four-unknown refined plate theory, and the Ritz method. The proposed solution is verified through comparison with existing results from the literature, and influence of some key factors on the non-dimensional deflection and the critical buckling load of the microplate are studied.

Utilizing unmanned aerial vehicles as a low-cost surveying method for landfill management: A case study at Quang Loi

Pham Van Dinh — 2025-12-25

Landfilling remains the primary method of municipal solid waste (MSW) management in Vietnam, particularly in rural areas, where small, unsanitary landfills lack monitoring systems. Traditional ground-based survey methods are costly, time-consuming, and pose safety risks, leading to a lack of crucial data for landfill management and environmental control. This study presents a low-cost unmanned aerial vehicle (UAV) photogrammetry method to assess the current status and propose appropriate management solutions for the Quang Loi landfill in Thua Thien Hue province. High-resolution orthophotos and a digital surface model were generated, allowing for accurate estimation of waste volume (82,200 m3) and remaining capacity (60,000 m3). At the current waste inflow rates, the landfill is projected to be full within 5-7 years. UAV imagery also revealed operational deficiencies, including a lack of daily cover, limited compaction, inadequate stormwater management, and widespread exposed plastic waste. A phased remediation and closure strategy is proposed to mitigate environmental risks. Overall, the results confirm that UAV photogrammetry provides a reliable, cost-effective, and integrated framework for holistic volumetric, operational, and environmental risk assessment for supporting informed landfill management decisions.

A catboost-based surrogate model for fast prediction of free vibration response in tri-directional functionally graded plates

Dieu T. T Do — 2025-11-13

Accurate numerical analysis of tri-directional functionally graded (3D-FGM) plates is computationally intensive, posing a major challenge for design optimization and reliability assessment. To overcome this, we propose an efficient surrogate model based on the CatBoost algorithm and benchmark its performance against a finely tuned Artificial Neural Network (ANN) for rapid prediction of free vibration responses. A high-fidelity dataset comprising 20000 samples was generated using a validated model that integrates Isogeometric Analysis (IGA) with Generalized Shear Deformation Theory (GSDT). Each sample includes eighteen input parameters (material control points) and three outputs: natural frequency, total ceramic volume fraction, and plate mass. The models were systematically evaluated by investigating the influence of hyperparameters and dataset size on prediction accuracy (measured by MSE and MAPE) and computational time. The results demonstrate that the optimized CatBoost model achieves nearly nine-fold lower test MSE and is over 10.8 times faster than the ANN. These findings highlight CatBoost as a highly accurate and efficient surrogate, enabling fast and reliable analysis of complex composite structures for future engineering applications.

Investigation of the bulk drag coefficient of nature-based breakwater by flow experiments

Ngo Thi Thuy Anh — 2025-12-25

Nature-based solutions for nurturing the coast, particularly mud and mangrove coasts, have gained significant attention and are emerging as a new trend in the context of coastal engineering. In this study, the bulk drag coefficients of a permeable structure, a brushwood fence, are investigated and assessed by Darcy-Forchheimer flow experiments. Two samples, assembled from a number of bamboo cylinders with two different densities (607 and 1209 cylinders/m²) and an average diameter of 0.02 m, are installed inside a square tube (26 cm × 26 cm). A steady flow discharge is forced through the samples, which naturally creates a hydraulic loss (a difference in water levels) between the upstream and downstream sides. The forces created by hydraulic gradient, a ratio of hydraulic loss to sample widths, are then investigated as the drag forces, in which the bulk drag coefficients (C¯d) plays a vital role in this study. The findings from this investigation conclude that the bulk drag coefficients depend on the flow stages (represented by Reynolds number, R_e) and reach significantly high values at low R_ebut become stable at high R_e. Our findings of C¯d indicate to have a similar trend to previous studies, that is, 2.0 for R_e > 2000 (turbulent flow) for cases with a lower density of 607 cylinders/m², while C¯d is greater than 2.0 for R_e < 2000 (laminar flow).

Study on technologies for preventing and removing fouling on steel structures in coastal environments

Vu Hoang Hung — 2025-12-25

In marine environments, particularly in estuarine regions of Vietnam, the adhesion of oysters and marine microorganisms to metal surfaces causes biocorrosion, significantly reducing the durability and operational efficiency of steel structures such as sluice gates. Although various technical solutions have been studied to mitigate this issue, a comprehensive approach that is both effective, environmentally friendly, and practical for field application remains elusive. Within the framework of a collaborative research project between Thuyloi University (Vietnam) and IHI Corporation (Japan), a combined technology using Micro-current and Ultrasonic irradiations was experimentally applied on a real sluice gate structure in Hai Phong. The results demonstrated that the solution effectively prevents and removes biofouling organisms, identifies optimal technical conditions for implementation in estuarine environments, and provides recommendations for selecting suitable gate materials to enhance corrosion resistance and extend structural lifespan.

Evaluation on comprehensive performance of sulfate activated slag self-compacting concrete

Vu-An Tran — 2025-12-25

The current study deals with the production and engineering properties of a self-compacting concrete (SCC) produced with sodium sulfate activated slag binder. A mixture of 5% calcium hydroxide and sodium sulfate varied at different values of 1, 3, 5, 7, and 10% by mass was used as the primary activator of the binder. The fresh properties of the concretes were identified by adapting slump flow, L-Box, air entrained volume, and unit weight. On the other hand, the properties of the hardened concretes were assessed by using the tests on dried density, flexural strength, compressive strength, drying shrinkage, ultrasonic pulse velocity (UPV) and water absorption. Experimental results illustrated that by properly adjusting dosage of superplasticizer (SP) in order to avoid an issue related to lost set, SCC productions were only successfully achieved with sulfate amount limited at 5%. The increment of the sulfate in the range of 1–5% seemed to denser the SCC structure due to the increased unit weight, reduced air entrains, improved strengths, decreased drying shrinkage, increased UPV, and decreased water absorption. Further increase of the sulfate amount in the range of 5–10% induced the hardened concretes with reductions on mechanical strengths, UPV, and water absorption, possible due to the reduced flowability. In this study, 5% of sulfate was considered as the optimum value to produce the concrete with the best quality except the drying shrinkage still decreasing with the sulfate increment.

Study on the salt intrusion in some river water sources serving for domestic water supply in coastal areas of Vietnam

Pham Thanh Dat — 2025-12-25

Saline intrusion in Vietnam’s coastal areas has been significantly increased by climate change and anthropogenic activities, particularly water resource exploitation. This paper presents a comprehensive assessment of salinity levels within river systems supplying domestic water, with a focus on the Mekong Delta, Central Coast, and Northern regions. The findings indicate that saline intrusion fronts have penetrated inland distances ranging from tens to hundreds of kilometers. This penetration results in pronounced seasonal and diurnal (hourly) variations in river water salinity. Measured concentrations range from several hundred to tens of thousands of mg/L (quantified as Total Dissolved Solids, TDS), or up to several tens of parts per thousand (‰). River systems exhibiting high average salinity (> 1 ‰) include the Re, Cam, and Ninh Co rivers (North); the Yen, Cai, and Ma rivers (Central); and the Cua Tieu, Cua Dai, and Co Chien rivers (Mekong Delta). A critical associated issue is the elevated concentration of bromide ions (Br-) in saline-affected waters. This presence significantly increases the formation potential of carcinogenic disinfection byproducts (DBPs) during the chlorination process. Consequently, this study proposes technical solutions designed to mitigate and adapt to these adverse impacts on domestic water supplies