Search Results (5)

The high-resolution seismic method can provide acoustic reflectivity images of shallow marine geology structures. In South Vietnam, the demand for construction materials like sand is high; therefore, the exploration of its deposits is considered in this study. This study investigated an around 200-square-kilometer area offshore Bac Lieu using 2D seismic sub-bottom lines. We employed the processed seismic amplitude and its seismic attributes as mean and variance textures to interpret the data. The processed seismic amplitude and its attributes can represent the young Holocene sediments (i.e., sand, silt, clay, and their mixtures) thanks to their different seismic patterns. Our interpretation result consists of 3D horizons of the seabed, Holocene silt, and sand sediments, which are compatible with the prior geological information, including three nearby drill holes. The seabed gradually descends from 10.0 m to 19.0 m over a horizontal distance of around 11 km. Moreover, the interpreted results show that the sand sediments reside in the center of survey area, with a maximum thickness of around 12.0 m. Interestingly, a fill sediment channel effectively separates two different zones of young Holocene sand and silt sediments. The findings provide valuable information for Vietnamese government officers to develop sustainable policies and regulations for marine mineral exploitation and exploration. Full article

Road construction usually relies on the utilization of natural aggregates as building materials. However, increasing pressure for sustainable roads highlights the importance of replacing natural materials with industrial byproducts. The scope of the present study was to identify feasible secondary raw materials for road subbase construction, and to investigate their environmental footprint in the context of Vietnam. This work examines road subbase alternatives such as manufactured sand (m-sand), granulated blast furnace slag (GBF), electric arc furnace slag (EAF), construction and demolition waste (CDW), and fly ash (FA). Based on the life-cycle assessment (LCA) approach, the environmental footprints of the alternative waste-based layers were compared with one another and with the corresponding conventional layers. The study comprises following working steps: (i) a comprehensive literature review of the respective materials, (ii) general chemical and soil mechanical analysis of road subbase substitutes, and (iii) LCA of the material alternatives in the context of the Vietnamese road construction sector. The results for the road subbase layer indicated that CDW and FA had lower impacts—particularly in the impact categories global warming potential and mineral resource scarcity. The overall LCA analysis for the road subbase layer highlighted that the greatest footprint contribution was involved in the construction material transportation processes. Thus, sourcing of materials closer to the site or the use of low-emission transport alternatives is needed. Full article

Urbanization is a global trend: Since 2007 more than 50% of the world’s population have been living in urban areas, and rates of urbanization are continuing to rise everywhere. This growth in urbanization has led to an increased demand for natural resources, in particular non-metallic minerals such as stones, sand and clay, which account for one third of the entire flow of materials. Generally, these materials are traded within regional markets. This close geographical link between the demand for building materials in urban areas and the material supply in the hinterland leads to massive interventions in the natural environment and landscape. These urban–rural linkages can be revealed by applying Material Flow Analysis (MFA) to the built environment in order to trace the flows of building materials. The objective of this paper is to present a method for quantifying regional material flows by considering the supply and demand of building materials. This will be applied to the Vietnamese case study area of Hanoi and its hinterland province Hoa Binh. The results indicate a consumption of almost 60% of the construction mineral reserves in total secured by planning in the hinterland province considering a period of 15 years. However, this does not allow for the general conclusion that raw materials are sufficiently available. The sand reservoirs are only sufficient for eight years and clay reserves are used up after four years. This increases the need to exploit further raw material reserves, which are becoming increasingly scarce and results in stronger interventions in nature In order to safeguard the hinterland from the negative impacts of urbanization, a new understanding of resource efficiency is needed—one that acknowledges both resource efficiency in the construction of urban structures and appropriate resource conservation in the provision of the raw materials from the hinterland. This will require the creation of new integrated planning approaches between urban and regional planning authorities. Regional MFA is one way of realising such an approach. Full article

This study was conducted to investigate factors impacting the application of environmental management accounting (EMA) and the relationship between EMA application and performance efficiency including financial and environmental sectors. The scope of research was to investigate construction material manufacturing enterprises in Vietnam with medium and large scales, which is considered one of the industries causing significant negative impacts on the environment. The questionnaires were sent to chief management accountants of 600 construction material enterprises in Vietnam from 2018 to 2019. This process obtained 418 valid votes. Using SPSS 22.0 software to process data, the research results indicate that there are six factors that positively influence the application of EMA practices, including government enforcement, stakeholder interest, positive environmental strategies, community expectations, professional education network, and financial condition, of which, government enforcement has the most significant and positive relationship with the adoption of EMA. On the other hand, it appears that the application of EMA positively impacts financial efficiency and environmental efficiency. As found by many previous studies, environmental efficiency also strongly positively impacts financial efficiency. Thus, innovative solutions to reduce environmental pollution can promote enterprises’ profitability. Full article

This novel study on cement paste material was conducted with the aim of keeping up with the rapid development of urban construction and contributing to the continuous improvement of building materials to overcome environmental issues. In this study, several kinds of industrial waste were used to enhance the properties of cement paste for application in a marine environment with a tropical climate, such as in Vietnam. This study focuses on evaluating the properties of cement paste containing cement replacement combining 0–30% fly ash, 0–10% silica fume, and plasticizer accounting for 0.3% and 0.4% of the binder by mass. Water demand, chloride ion and sulfate ion permeability, and microstructural properties of the cement paste were determined by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscope (SEM) and they were investigated after 28 and 56 days. The test results show that an optimum mixture could be obtained with the use of 20% fly ash, 10% silica fume (replacing Portland cement), and 0.4% plasticizer. The application of such materials to sea dikes affected by a tropical climate (characterized by heat, humidity, salty seawater, many big storms, large waves, and strong tides) was investigated for four years on the Vietnamese coast. The test results indicate that fly ash and silica fume can improve the corrosion and abrasion resistance of concrete in coastal areas with a tropical climate, such as in Vietnam. Full article