Tạp chí của Viện Vật liệu xây dựng - Bộ Xây dựng
Developing a BIM (Building Information Modeling) implementation process in accordance with ISO 19650 for construction companies
In the context of digital transformation in the construction industry, Building Information Modeling (BIM) has been increasingly adopted by construction companies in Vietnam. However, BIM implementation in practice is often limited to the use of software tools, lacking a standardized information management framework and full compliance with international standards such as ISO 19650. This limitation leads to inefficiencies in coordination, information control, and long-term data utilization throughout the project lifecycle. This study aims to develop a BIM implementation process in compliance with ISO 19650 that is suitable for construction companies in Vietnam. The research methodology includes literature review, analysis of ISO 19650 requirements, process modeling using Business Process Model and Notation (BPMN), and a questionnaire survey conducted among engineers working in BIM environments. Based on the findings, a BIM information management process is proposed, focusing on key components such as Employer’s Information Requirements (EIR), BIM Execution Plan (BEP), Common Data Environment (CDE), and defined roles and responsibilities in accordance with ISO 19650. The survey results indicate that the proposed process is technically feasible and provides clear benefits, including improved information transparency, enhanced version control, and more effective collaboration among project stakeholders. This study contributes a practical reference framework to support construction companies in implementing BIM in alignment with ISO 19650, thereby promoting standardized information management and sustainable digital transformation in the construction sector.
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Application of Material Flow Analysis to propose Greenhouse Gas Mitigation Solutions for the Pulp and Paper Industry – A Pilot Study at Vina Kraft Paper at Ho Chi Minh city
Greenhouse gas (GHG) emissions in the paper industry mainly originate from the combustion of fossil fuels to generate energy, as well as from chemical and biological processes that occur during pulp and paper production. Material Flow Analysis (MFA) is an effective tool for quantifying material flows across different stages of paper production and identifying intervention opportunities to reduce GHG emissions, thereby contributing to carbon neutrality and net-zero targets. Research results from the Vina Kraft paper show that waste paper is the primary raw material used in production, accounting for 96.55% of the total paper inputs. The rate of recycled and reused paper at the mill is 4%, and the total GHG emissions amount to 642,277.1 tons of CO₂e. Enhancing the recycling and reuse of waste paper in the mill’s production process will help reduce GHG emissions associated with manufacturing activities. Furthermore, utilizing waste for energy generation or as raw materials in agricultural and construction production can contribute to environmental protection and further reduce greenhouse gas emissions. The findings obtained from the pilot study at the Vina Kraft can be applied to other facilities in the pulp and paper industry, supporting the Vietnamese government’s commitment to climate change mitigation.
Standardization of hydraulic binder materials – achivements and orientation of the Vietnam Institute for Building Materials
This paper provides an overview of recent standardization activities in the field of building materials conducted under the leadership of the Vietnam Institute for Building Materials (VIBM). The focus is placed on the group of hydraulic binders, encompassing standards for masonry cement, Composite Portland cement, ground limestone additive, ground granulated blast furnace slag (GGBFS), fly ash, and blended hydraulic binders. The formulation and adoption of these standards have significantly contributed to the improvement and harmonization of the Vietnamese national standards system (TCVN) with European Standards (EN). These efforts align with the objectives of technological innovation, efficient resource utilization, energy conservation, and CO₂ emission reduction. The outcomes of this work provide a solid basis for advancing the development of green and sustainable building materials in Vietnam.
Identifying and analyzing factors influencing sustainable procurement in construction projects in the Mekong Delta
In the context of Vietnam’s construction industry transitioning toward green growth, sustainable procurement has increasingly been recognized as an important tool for integrating environmental, social, and economic objectives into the selection of construction materials, contractors, and services. However, in the Mekong Delta region, the implementation of sustainable procurement in civil construction projects remains limited due to multiple barriers related to institutional frameworks, market conditions, organizational capacity, and flood-prone infrastructure characteristics. This study aims to identify and analyze the factors influencing the implementation of sustainable procurement within the specific context of the Mekong Delta. A quantitative research approach was adopted, based on a survey of 500 relevant stakeholders using a five-point Likert-scale questionnaire. The reliability of the measurement scales was assessed using Cronbach’s Alpha, and the underlying factor structure was extracted through Exploratory Factor Analysis (EFA). The results indicate that 38 observed variables converge into four main factor groups, comprising two barrier-related factors and two benefit-related factors. Based on these findings, the study proposes several managerial implications to promote sustainable procurement practices in civil construction projects in the Mekong Delta.
Evaluation of the effects of oyster shell powder on mechanical properties of cement concrete
This study evaluates the effects of partially replacing cement with finely ground oyster shell powder on the mechanical properties of cement concrete. The oyster shells were processed through cleaning, sun-drying, grinding, calcination, and sieving. Experimental mixtures were prepared with replacement ratios of 2%, 4%, and 6% by weight of cement. The results indicate that a 2% replacement ratio is optimal, improving early compressive strength and enhancing flexural tensile strength by up to 58% compared to the control, while the elastic modulus remained nearly unchanged. The findings suggest that oyster shell powder has potential as a supplementary cementitious material, contributing to emissions reduction and waste reuse in sustainable construction.
A comprehensive review of salt-contaminated sand and mineral admixture–modified Engineered Cementitious Composites (ECC): Properties and application potential in transportation infrastructure construction
This paper summarizes and analyzes previous studies related to salt-contaminated sand, mineral additives (fly ash [FA] and ground granulated blast-furnace slag [GGBFS]), and their potential combinations in the production of engineered cementitious composites (ECC) for transport infrastructure components. Salt-contaminated sand in Vietnam has large reserves, low SO₃ content, and relatively fine particle size, and contains Cl⁻ ions that can have adverse effects if not properly controlled. Mineral additives (FA and GGBFS) are rich in Al₂O₃, which can promote pozzolanic reactions, forming stable products such as Friedel's salt and C–S–H gel, thereby significantly improving both the mechanical strength and durability of ECC. The combination of salt-contaminated sand and mineral additives is noted to be able to improve compressive, tensile and flexural strengths; reduce drying shrinkage; increase fatigue resistance; and enhance self-healing and anti-erosion in chloride and sulfate-containing environments. The results show that the ECC system using salt-contaminated sand combined with mineral additives is a potential solution for construction materials for transport infrastructure in the context of shortage of natural sand resources and requirements for sustainable development.
Circular economy in construction materials production: Current status, potential and implementation solutions
The depletion of natural resources, environmental pollution, and climate change necessitate a transition from the linear economic model to the circular economy (CE) model. The construction materials industry is among the sectors with high resource consumption and greenhouse gas emissions. This paper synthesizes investigation, survey, and analytical results to assess the current situation and potential for CE implementation across sub-sectors of Vietnam’s construction materials industry (including cement, ceramics, construction glass, tiles, fired bricks, and unfired bricks). It further proposes appropriate solutions and a roadmap aligned with the national context. The research findings indicate that: (i) the construction materials industry has substantial potential for utilizing various types of industrial waste as alternative raw materials and fuels; (ii) the adoption of CE can reduce CO₂ emissions, conserve resources, and lower waste treatment costs; however, (iii) there remain significant technical, legal, and market barriers. Based on these findings, the paper proposes an integrated set of policy, technological, managerial, and financial measures, along with a three-phase roadmap (2025–2030: pilot phase; 2030–2040: expansion; 2040–2050: integration and optimization). Specific recommendations are provided to facilitate the practical implementation of the circular economy in Vietnam’s construction materials production sector, contributing to the achievement of sustainable development goals and national emission reduction commitments.
Sustainable water resources management in China: An integrated approach to institutions, technology, and the circular economy
China is facing some of the most severe water resource challenges globally, including water scarcity, increasing pollution, and intense pressure from large-scale urbanization and industrialization. Over the past five decades, China has gradually developed a sustainable water resource management model based on an integrated approach that combines institutional reform, stricter environmental standards, technological innovation in wastewater and sludge treatment, and the promotion of a circular economy. This paper systematically analyzes the transformation of China’s water governance in both thinking and practice, clarifies the three core pillars—institutions, technology, and circular economy—and draws key lessons for Vietnam and other developing countries.
Solutions for mobilising sustainable investment capital for Vietnam’s coastal dike system to adapt to climate change
In the context of climate change, about 2/3 of Vietnam’s coastal dike system does not meet safety standards to protect coastal populations and infrastructure. This study aims to assess the current state of the sea dike system and propose solutions to improve its safety and effectiveness. Meanwhile, state budget funds are insufficient to meet the investment needs for the sea dike system, making it crucial to mobilize sustainable investment sources for the construction, upgrading, and maintenance of this system. The article references countries' experiences worldwide while also studying Vietnam's legal and practical context. Based on this, it proposes several solutions for mobilizing sustainable investment capital for Vietnam's sea dike system to adapt to climate change. The specific solutions are as follows: (i) Optimize and diversify public investment sources; (ii) Attract and mobilize private capital; (iii) Maximize international funding and multilateral cooperation; (iv) Develop innovative financial mechanisms and risk management; (v) Strengthen institutional capacity and financial governance; and (vi) Integrate nature-based and sustainable development solutions. The successful implementation of these solutions contributes to mobilizing diverse, transparent, and sustainable investment capital to enhance climate change adaptation capacity for coastal areas in Vietnam.
Study on Risks in Material Utilization during the Construction of Major Transportation Infrastructure Projects in Vietnam
This report examines the critical risk groups associated with the mobilization and utilization of construction materials in large-scale transportation infrastructure development projects in Vietnam. The rapidly increasing demand for materials-amid the simultaneous implementation of multiple expressways, coastal routes and other strategic works-has amplified the likelihood of supply shortages, particularly for embankment soil, construction sand and various types of aggregates. Beyond the heavy reliance on traditional quarries, delays in licensing new material sources and competition among concurrent projects further heighten the vulnerability of supply chains to disruption. Material heterogeneity, small-scale and loosely regulated extraction activities and inconsistent quality control increase the need for additional technical treatment, generating extra costs and potentially delaying project schedules. Logistics systems also face significant pressures, as materials often must be transported over long distances; existing on-site infrastructure is frequently narrow, weak, or shared with local traffic, resulting in congestion, prolonged delivery times and reduced transport efficiency. In parallel, large-scale material extraction introduces considerable environmental and socio-ecological risks, influencing agricultural production, coastal geomorphology, riverine sediment dynamics and inland ecosystems. Furthermore, shortcomings in quarry planning, insufficient integration of supply-demand data and the absence of effective regional coordination mechanisms contribute to heightened market uncertainty. The early identification and systematic risk assessment of these challenges are essential to optimizing resource allocation, safeguarding project timelines and enhancing the overall sustainability of major national transportation infrastructure initiatives in Vietnam.
Study on the compressive strength of mortar and concrete using oyster shell aggregate as a river sand replacement
This study evaluates the effect of using crushed oyster shell aggregate as a partial replacement for river sand on the compressive strength of mortar and concrete. Mortar specimens were prepared with river sand replacement rates of 0%, 5%, 10%, and 15%; the concrete mixture used the optimal 15% replacement level. The results indicate that, for mortar, the highest 28-day compressive strength was achieved at a 15% replacement level. For concrete, although the slump decreased by approximately 37.5%, the 28-day compressive strength remained comparable to that of the control mixture. The stability in compressive strength was attributed to the rough surface texture of the oyster shells and the contribution of CaCO3 to secondary chemical reactions. This research highlights the potential of using oyster shell waste as a sustainable material in construction applications in Vietnam.
Study on the Manufacturing of High-Strength, Water-Resistant Concrete for the Underground Structures of High-Rise Buildings in Ho Chi Minh City
The paper presents the results of research on the development of high-strength, watertight concrete aimed at improving compressive strength, crack resistance, and impermeability for the construction of underground and multi-story facilities, especially in Ho Chi Minh City. Five concrete mix designs were prepared according to ACI 211.4R-08, combining blended Portland cement PCB40, Duyen Hai thermal power fly ash, silica fume SF-90, and dispersed polypropylene fibers. Workability, mechanical properties, and impermeability of the concrete were evaluated according to current Vietnamese standards. Experimental results show that the concrete achieved an average 28-day compressive strength of 63.5–73.6 MPa, flexural tensile strength of 7.40–8.02 MPa, and an average elastic modulus above 37.4 GPa. Water absorption was below 8 %, and impermeability reached grades W12–W19 according to TCVN 3116:2022. The concrete mix exhibited good workability, with a slump of 19.0–22.0 cm, remained stable over time, and showed no segregation, suitable for practical field construction. The results confirm that high-strength, watertight concrete is a sustainable and effective solution for underground infrastructure in Ho Chi Minh City, while also reducing cement consumption, utilizing industrial by-products, and promoting environmentally friendly construction materials.
Effects of BFRP retrofitting and cyclic loading on the load-bearing capacity of reinforced concrete beam-column joints
This paper investigates the effects of Basalt fiber reinforced polymer (BFRP) retrofitting and cyclic loading on bearing capacity of reinforced concrete beam-column joints with orthogonal beams. Experiments were conducted on eight beam-column joints. These joints were classified into four groups; each group had two joints. One group was not retrofitted (control group). Three remaining joints were retrofitted with various configurations. For each group, one joint was monotonically loaded and one joint was cyclically loaded. The results showed that damage mode was in the form of concrete crushing in the compression zone and concrete cracking in the tension zone. The damage was concentrated on the beams, while the damage did not appear on the columns. Under monotonic loading, BFRP retrofitting increased the ultimate load of the joints by about 8.5%. Under cyclic loading, BFRP retrofitting increased the ultimate load by 3.3–7.0% compared with that of the control joint. Cyclic loading had a great influence on the ultimate load capacity of the joints. Compared to the control joint subjected to monotonic load, cyclic loading reduced the ultimate load of the unretrofitted joint by 14.3% and the ultimate load capacity of BFRP retrofitted joints by 8.3–17.2%.
Using VBA in Excel to analyze plane beam reactions by the matrix method
A simple computational tool for planar beam analysis is developed in Excel using VBA based on the Matrix Structural Analysis (MSA) method. This method describes the relationship between nodal forces, nodal displacements, and structural stiffness through a matrix-form equilibrium equation. The program automates the calculation process, including stiffness matrix formulation, conversion of distributed loads into equivalent nodal forces, and solving the system of equations to determine displacements, support reactions, and internal forces of the beam. The results are presented visually through tables and shear–moment diagrams. In addition, the study compares the results of MSA with those of the Finite Element Method (FEM), highlighting the simplicity, transparency, and applicability of MSA in teaching and linear structural analysis research.
Determination of characteristic values of soil parameters in foundation design standards in Vietnam
Vietnam is currently in the process of developing and improving its national standards (TCVN) for the construction industry, many of which are adapted or referenced from international standards. However, significant inconsistencies remain among existing standards, particularly in the calculation methods for determining and applying the characteristic values of soil parameters in foundation design. This study reviews and compares the relevant provisions of current Vietnamese standards (TCVN) with those of international standards. The results indicate that the TCVN standards are not yet consistent in defining and applying characteristic values and reliability factors in geotechnical calculations. Although both TCVN 9362-2012 and TCVN 10304-2025 specify characteristic values, their differing approaches lead to variations in calculated results, affecting the reliability and uniformity of design outcomes. The findings clarify the fundamental principles behind the calculation methods used in these standards and emphasize the urgent need to systematize and harmonize TCVN geotechnical standards. Developing clear, user-friendly, and harmonized standards will enhance the effectiveness of design, management, and implementation in construction practice in Vietnam.
Impacts, challenges, and solutions of urbanization on urban stormwater runoff
The analysis of urbanization and climate change impacts on stormwater runoff demonstrates that the rapid expansion of impervious surfaces, the loss of natural retention areas, and aging, capacity-deficient drainage networks are the primary drivers of increased peak flows and heightened flood risk. The study integrates hydrometeorological datasets, remote-sensing observations, land-use change analysis, and assessments of drainage system performance to clarify how urbanization alters runoff dynamics and creates systemic bottlenecks in stormwater management. Results indicate that surface runoff in highly urbanized areas can increase by a factor of 4–5 compared with natural conditions, with flood peaks occurring more rapidly and with greater intensity. Moreover, extreme rainfall events during 2024–2025 repeatedly exceeded the design thresholds of existing drainage systems, triggering widespread and severe flooding in Hanoi, Ho Chi Minh City, the Central coastal region, and even midland urban centers. High-density development, insufficient permeable and retention space, and fragmented urban planning frameworks further exacerbate socio-economic vulnerabilities and environmental degradation. The study recommends a suite of measures, including integrated urban–hydrological planning, climate-adaptive drainage upgrades, expansion of nature-based green infrastructure, enhanced early-warning and smart-operation systems, and strengthened community-based management to mitigate peak runoff, increase urban resilience, and support sustainable urban development.
Introducing some draft standards for the field of building in glass for the year of 2025
In recent years, the work of developing new standards and reviewing current standards in the field of construction glass materials has always been carried out promptly to update and supplement changes in product quality standards, create compatibility in production and use to protect consumer rights, help businesses and the state manage products on the market. Therefore, the Ministry of Construction has assigned the Institute of Construction Materials to carry out the tasks of developing standards in the period of 2024-2025, including: Glass in building. Special basic products - Glass ceramics - Evaluation of conformity/Product standard, code TC 82-24; Glass in building – Glazing and airborne sound insulation – Measurement of the mechanical impedance of laminated glass, code TC 83-24; Glass in building. Determination of energy balance value. Calculation method, code TC 84-24; Bonding sealants. Bonded glazing sealants for direct light exposure, code TC 85-24; Glass in building - Determination of the emissivity, code TC 95-24 và Glass in building. Safety in case of fire, fire resistance. Glass testing methodology for the purpose of classification, code TC 96-24. These standards, when issued, bring positive benefits such as ensuring product quality, enhancing safety, promoting innovation to improve quality and facilitating international trade and integration.
Identification of schedule risk factors associated with Nominated Subcontractors (NSC) in Vietnamese construction projects
In the current context of construction investment in Vietnam, it has become increasingly common for main contractors to enter into contracts with Nominated Subcontractors (NSCs) as required by the Owners. This mechanism often stems from requirements regarding specific technical expertise, brand or equipment origin restrictions, and the Owner's overall project management policies. While the use of NSCs leverages the expertise capabilities of experienced specialized firms, this mechanism concurrently creates numerous risks during project execution, particularly those affecting construction schedule performance. This study was conducted based on the analysis of 106 valid survey responses collected from a total of 121 questionnaires, combined with the expert opinions of 11 professionals with 6 to 35 years of experience in the Vietnamese construction sector. The research results identified 21 key risk factors associated with the use of nominated subcontractors. Based on statistical analysis and validation against expert assessments, the study proceeded to rank the impact levels of these risk factors and propose specific mitigation strategies for the 10 factors assessed as having the most severe impact on project schedule performance.
Prediction of jump length, bed shear stress, and energy loss using machine learning models for a steady, free hydraulic jump on rough beds
Determining or predicting the characteristics of hydraulic jumps over rough beds remains a complex issue in hydraulic engineering. While recent experimental and numerical simulation studies have enhanced understanding of this phenomenon, an efficient and accurate predictive approach is still required for the optimal design of stilling basins under complex flood flow conditions. This study proposes an advanced method for predicting the main hydraulic parameters of free and stable hydraulic jumps on right triangular prism rough beds, including jump length (Lj/y₁), bed shear stress (e), and energy loss (ΔEL/E₁). Machine learning techniques, namely Decision Tree Regression (Fine Tree) and Support Vector Regression (SVR), were applied to model the nonlinear relationships between rough bed geometry and supercritical flow behaviour. The study results showed the models achieved high predictive accuracy (R² = 0,91 ¸ 0,99) with low RMSE error values, confirming their strong capability in predicting the complex hydraulic phenomena. The findings demonstrated that artificial intelligence (AI) can serve as a reliable and cost-effective alternative to physical model experiments and numerical simulations, offering a robust scientific basis for analysing and optimising the hydraulic performance and energy dissipation efficiency of hydraulic jumps over rough beds under complex hydraulic conditions.
Integrated BIM 4D-EVM Solutions for Construction Schedule Control in Vietnam
Construction schedule control in Vietnam remains challenged by fragmented data, traditional management practices, and the lack of integration between design, execution, and cost information. Building Information Modeling (BIM) 4D and Earned Value Management (EVM) are two advanced tools that respectively support visualizing construction sequences and quantitatively evaluating schedule-cost performance. However, these methods are mostly implemented independently and an integrated BIM-EVM framework has not yet been established in Vietnam. This study synthesizes the theoretical foundations of BIM 4D and EVM, analyzes their current adoption in Vietnam, and identifies key barriers related to data standardization, technology capability, human resources, and regulatory frameworks. Based on these findings, the study proposes a set of technical, technological, and organizational solutions for integrating BIM 4D and EVM in schedule control, including standardized WBS coding systems, unified BIM-schedule-cost workflows, Common Data Environment (CDE) deployment, application of IoT/UAV/3D scanning for real-time progress data, and improvements to the legal and institutional environment. The results provide a practical and feasible direction for data-driven construction schedule management in the context of Vietnam’s digital transformation.
Effect of fly ash content on waterproofness and shrinkage of concrete
This paper aims to evaluate the effect of fly ash (FA) content on the strength and durability of cement concrete. In this experimental study, the properties tested were compressive strength (CĐCN), water resistance and shrinkage of concrete. For this purpose, a type F FA concrete mix was designed with five levels of FA replacing cement PCB40 (0%, 20%, 25, 30% and 35%). The test results showed that at 28 days, the CĐCN of the FA 20 - 35% concretes decreased compared to the 0% control sample, the concrete with FA dosage of 20% - 30% had higher water resistance than the control sample, but when it increased to 35%, the water resistance began to decrease compared to the control sample. At 56 days old, the 20% FA sample had a higher CĐCN than the control sample by about 1,5%, the remaining mixtures were slightly lower than the control sample by -1,1%, -3,3% and -6% respectively, but all FA concrete mixtures had better waterproofing ability than the control sample. Regarding shrinkage, the experimental results showed that at 28 and 56 days old, the concrete with increased FA content had a decrease in shrinkage compared to the control sample and decreased almost linearly.
Building construction norms for urban railways in Vietnam: Theoretical and practical foundations
At present, the rapid pace of urbanization in Vietnam is generating major challenges for urban transport systems, including increasing congestion, pollution, and traffic accidents. Consequently, the development of urban railways is considered by the Government to be an urgent solution, with a plan for Hanoi and Ho Chi Minh City to establish a 580-km network by 2035, meeting 30–35% of public passenger transport demand. However, Vietnam currently lacks a dedicated cost-norm system for urban railways. As a result, project developers must rely on foreign cost norms or those from unrelated sectors, which makes cost management difficult. Specifically, the Cat Linh–Ha Dong line applied Chinese cost norms, Metro Line No. 1 in Ho Chi Minh City used investment benchmarks from the Asian region, while Metro Line No. 2 had to develop its own project-specific norms. International experience shows that developed countries such as Japan and China have established dedicated cost-norm systems for urban railways, whereas Vietnam only has general norms applicable across sectors and several specialized norms, but none specifically for urban rail systems. Based on the research findings, the paper highlights the critical role of developing a comprehensive cost-norm framework to ensure effective, transparent, and technically appropriate cost management for the complex nature of urban railway projects. From this, the paper proposes four key solutions: (1) Establishing a set of specialized cost norms for urban railways tailored to Vietnam’s conditions; (2) Selectively adopting international experience and adapting it to domestic practice; (3) Institutionalizing a dedicated legal framework for cost norms in urban infrastructure; and (4) Gradually developing a cost-norm model that incorporates digital technologies such as BIM, AI, and Big Data.
Overview of bagasse recycling as a material for Portland cement concrete: Mechanical properties, durability, and application potential in rigid pavements
This paper provides a comprehensive review of the potential for recycling sugarcane bagasse—an abundant agricultural by-product in Vietnam and tropical countries—as an raw material for Portland cement concrete (PCC) and its applicability in rigid pavement construction. Two primary recycled forms, sugarcane bagasse ash (SCBA) and sugarcane bagasse fibers/ particles (SBF), are examined in terms of processing methods, mechanisms of action, and their influence on the mechanical and durability properties of concrete. Synthesized findings indicate that properly calcined and finely ground SCBA exhibits significant pozzolanic activity, enhancing compressive strength, microstructural densification, and long-term durability. Meanwhile, SBF functions as a natural reinforcing material that improves flexural capacity, crack resistance, and ductility. Assessment based on TCCS 39:2022 and TCCS 40:2022 standards shows that recycled bagasse materials can potentially satisfy several technical requirements for PCC pavements, especially in sustainable and low-carbon infrastructure development. However, current studies remain largely limited to laboratory-scale investigations. Therefore, further experimental, pilot-scale, and long-term performance studies are essential to validate the feasibility and practical implementation of bagasse-based materials in Vietnam’s transportation infrastructure.
Investigation of mechanical properties of fine-grained concrete incorporating recycled PET flakes under thermal effects
This study aims to determine the effects of high temperature on some mechanical properties of fine aggregate concrete with recycled PET (polyethylene terephthalate) flakes (Concrete with Waste Recycled Plastic – CWRP). Concrete mixtures with 10%, 15%, and 20% volume replacement of PET flakes are investigated for their thermal behavior. For this study, beam and cube specimens were cast to determine the flexural and compressive strength of the CWRP before and after exposure to heat, while simultaneously assessing the workability of the mixtures.The results indicate that as the percentage of substituted PET increases, the workability of the mixtures tends to decrease. Increasing the PET content also leads to reductions in both the flexural and compressive strength of CWRP at room temperature. Under high-temperature conditions, the study shows that the thermal sensitivity of CWRP increases with higher PET content. Based on the investigation, substituting around 10% PET appears to be optimal for maintaining acceptable workability and mechanical properties of CWRP under ambient temperature conditions.
Variation of PM2.5 concentration in central areas of Hanoi city and proposing PM2.5 pollution control measures
Resolution No. 57/2025/NQ-HĐND of Hanoi, which specifies the criteria, conditions, and roadmap for implementing low-emission zones in the capital city according to the 2024 Capital City Law, has been issued. This is a major step forward in strongly implementing pollution reduction solutions in the central area of ​​the capital. To minimize emissions of pollutants in general and PM2.5 dust in particular, comprehensive solutions are needed, based on the causes of emissions. This study surveyed and assessed the current state of PM2.5 dust pollution in several streets in Hanoi's Old Quarter to identify the causes of pollution. Based on these results, the study proposed to PM2.5 pollution control measures.
Assessment of the Feasibility of Using Local Fill Materials in the Southern Key Economic Region for Roadbed Construction in Low-Lying Riverside Areas
The administrative boundary merger of Southern provinces and the large-scale infrastructure development orientation have created an urgent demand for fill materials, particularly for road subgrades in floodplain areas of the southern key economic region. In the context of increasingly scarce traditional materials, limestone crushed stone mix of 0÷4,0 cm, widely distributed in the mountainous areas bordering Cambodia, emerges as a potential alternative due to its good mechanical properties and easy local availability. This study evaluates the feasibility of using this material combined with 10÷20% fly ash from the Duyen Hai 1 thermal power plant to improve strength, water resistance, and reduce settlement. The results indicate that the material meets technical requirements, reduces costs, utilizes industrial waste, and aligns with the principles of the circular economy. Furthermore, the study emphasizes the importance of sustainable extraction management and the establishment of local technical standards, contributing to the development of green and sustainable infrastructure in the southern key economic region.
Research on creating bricks alumosilicat material from clay in Chi Linh, Hai Phong city by un-roasted method
Unburnt bricks alumosilicat was made by kaolin, clay and fireclay. Effect of composition and particle size of clay on the strength of the bricks were studied. The strength was tested using the E156 machine from Matest, the contruction was examined by Infrared spectroscopy (IR), X-ray diffraction (XRD). The results showed that the material that contains 85% fireclay, 2 % kaolin, 13 % clay was the highest strength. The material was the highest strength when particle size of clay ≤ 0.15 mm.
Study on the Influence of Slope Geometry on Slope Stability under the Impact of Climate Change
In the Central and Central Highlands regions of Vietnam, characterized by predominant mountainous terrain and widespread distribution of weathered soils (clays and silty clays), prolonged intense rainfall events frequently induce severe slope failures, particularly along major transportation routes such as National Highways 1, 20, and 27C. This study assesses the influence of rainfall intensity and slope geometry on slope stability under rainfall infiltration. The analysis methodology is grounded in the theory of transient seepage, incorporating the soil-water characteristic curve (SWCC) equation proposed by Leong and Rahardjo [7], combined with the unsaturated soil shear strength model by Fredlund and Rahardjo. Numerical models were developed for slopes with heights Hs = 6–18 m, inclination angles β = 30°–45°, three representative soil types (saturated permeability ks = 10⁻⁴ to 10⁻⁶ m/s, effective cohesion c' = 10 kPa, effective friction angle φ' = 26°), and rainfall intensities Ir = 3–360 mm/h over a 24-hour duration. Results indicate that rainfall intensity (Ir) is the dominant factor affecting slope stability: when Ir ≥ ks, rapid saturation occurs, leading to instability (factor of safety FoS < 1) and FoS reductions ranging from 5.63% to 61.2%. In contrast, geometric factors exert a secondary influence: a 300% increase in slope height results in a 40.7% reduction in FoS; a 50% increase in inclination angle leads to FoS reductions of 11.4% to 26.2%
Solutions to improve economic efficiency when applying BIM to investment projects in Hanoi
Building Information Modeling (BIM) plays a key role in improving the economic efficiency of investment projects through information integration, process optimization and cost-risk reduction throughout the entire project life cycle. The application of BIM brings comprehensive economic efficiency to investment projects, helping to save costs, shorten progress, improve quality and efficiency of public investment capital use. Researching solutions to improve the economic efficiency of applying BIM to investment projects in Hanoi is urgent and has high practical significance.
Mechanical Properties of Glass/Carbon Fiber Hybrid based on Epoxy Epikote 828 Composite Materials
This study investigates the effectiveness of single-fiber reinforcements (carbon or glass) in comparison with glass/carbon hybrid reinforcements in epoxy resin (Epikote 828) based composites. The results show that composites reinforced with a single type of fiber exhibit mechanical properties governed by the intrinsic characteristics of the respective reinforcement. In contrast, the incorporation of glass/carbon hybrid fibers leads to a synergistic improvement in the overall mechanical performance. Specifically, the hybrid composite achieves a tensile strength of 205 MPa, a flexural strength of 331 MPa, and an impact strength of 75 kJ/m². The fracture morphology is analyzed by scanning electron microscopy (SEM), while the thermal stability is evaluated using thermogravimetric analysis (TGA). The results demonstrate that hybrid fiber reinforcement significantly enhances the thermal stability of the composite compared with that reinforced solely with glass fibers.