Scientific Review Engineering and Environmental Sciences (SREES)

Corrosion analysis of concrete based on industrial waste and bacteria by non-destructive test methods

Kharisma Wira Nindhita — 2025-06-30

Corrosion of concrete can lead to cracking and a decline in serviceability, necessitating effective methods to minimize the risk of corrosion. This study investigates the use of pozzolanic materials, specifically fly ash, bottom ash, and silica fume, combined with Bacillus subtilis bacteria as fillers to enhance the concrete structure’s resistance to corrosion. The research involves substituting fly ash (15–25%) and silica fume (5–15%) for cement by weight, alongside replacing sand with bottom ash at 15%. Additionally, Bacillus subtilis is incorporated into all pozzolanic concrete specimens. The study evaluates the mechanical properties of the concrete and employs non-destructive testing to correlate the physical condition with test results while preserving the structural integrity. The findings demonstrate that the inclusion of fly ash, bottom ash, silica fume, and Bacillus subtilis bacteria improves the mechanical properties of the concrete and effectively reduces the rate of corrosion, highlighting the potential for these materials to enhance the durability of concrete structures.

Flexural and tensile behavior of rubberized concrete: experimental analysis

Loubna Enkaiki — 2025-06-30

The escalating accumulation of rubber waste, especially from end-of-life tires, represents a very significant and pressing environmental challenge that requires particular attention from environmental organizations worldwide, as well as industries, to minimize its negative effects on ecosystems, human well-being, and the planet’s long-term sustainability as much as possible. The goal of this study is to explore a sustainable solution by introducing crumb rubber into a concrete mixture and evaluate its feasibility for structural applications. Thus, crumb rubber was introduced at different percentages by volume (0%, 10%, 20%, and 30%) to examine its effect on density, splitting tensile strength, and flexural behavior. The results shed light on the potential of rubberized concrete as an eco-friendly substitute while addressing its challenges. In fact, at 30% of crumb rubber content, density decreased by 5.6%, while splitting tensile strength decreased by 45%. However, beam flexural breaking strength marginally decreased by 9%, and deflection at mid-span decreased by around 13% for 30% of crumb rubber content. The failure mode evolved from brittle in concrete to slightly ductile with increased rubber content. The cracks observed in both reference concrete and rubberized concrete were similar, implying that the introduction of rubber did not result in a significant change in the overall behavior of the concrete at ultimate strength.

Life cycle assessment in the Visegrad Group: a bibliometric analysis

Libor Ansorge — 2025-06-30

Purpose: Life cycle assessment (LCA) research has been going on for several decades. However, it is not obvious how the post-communist countries of Central Europe participate in LCA research. The aim of this paper is to gather knowledge on the recent progress of scientific research related to LCA in the Visegrad Group (Visegrad Four, V4). Methods: A bibliometric analysis was chosen for the evaluation. Studies published by authors with affiliations in the V4 countries were extracted from the Scopus database. Descriptive analyses were performed, such as analyzing the distribution of types of scientific papers, language, journals used, keywords, and research fields. Using the VOSviewer application, bibliometric mapping was performed to express the links between individual works. The most active authors from the V4 countries and the most influential articles were identified using citation analysis. Results and discussion: A total of 1,665 studies have been found. Almost all studies originate from engineering or environmental sciences. Poland is the most active in LCA research within the V4. However, the most active scientists are affiliated with Hungarian universities. Likewise, the most cited scientist carried out most of his research in LCA at universities in Hungary. Slovakia has the least developed LCA research. It has also been noted that there is a low level of collaboration among authors from V4 countries. Conclusions: The analysis demonstrated differences in LCA research within the V4. Nevertheless, LCA research is gaining popularity in all V4 countries, albeit slowly. At the same time, LCA is of fundamental importance, especially in the implementation of European environmental legislation in practice and in achieving the goals of sustainable development. The findings obtained through this analysis can serve not only researchers working in LCA research but also scientific managers in the management of research in this area.

The impact of the depollution project on the environmental condition of the Salé coastline

Youssef IDRISSI — 2025-06-30

The city of Salé, situated along Morocco’s Atlantic coast, faces severe pollution due to human activities. Significant discharges of solid and liquid waste have resulted in contamination along its coastline, affecting water used for swimming, fishing, and irrigation. This has raised concerns about the quality of life for residents and the sustainability of local natural resources. This study evaluates the impact of the depollution project, part of the Bouregreg Valley development, on the physicochemical and bacteriological quality of Salé’s coastal waters. Monitoring was conducted at three stations to assess the spatiotemporal evolution of water quality, focusing on indicators of fecal contamination (fecal coliforms – FC, fecal streptococci – FS). The results show a notable improvement in the physicochemical quality of the waters. However, bacteriologically, the waters remain highly polluted and unsafe for swimming, with pollution primarily of human origin (CF/SF > 4).

Effect of pH value on contaminated clay soil

Ethar Wahab Rasheed — 2025-06-30

Clay soil is one of the most unusual and widely used soil types in geotechnical engineering and construction due to its various physical and chemical properties that make it a key material in many engineering applications. This research focuses on studying the effect of changes in pH resulting from acidic contaminants, an important indicator of chemical reactions inside the soil, and their effect on the geotechnical characteristics of clayey soil. These contaminants simultaneously alter pH values, making the study of these changes essential for understanding the extent of deterioration in soil mechanical and chemical properties and assessing the damage caused by contamination. The study covered fundamental geotechnical checks, such as the Atterberg limits, Proctor check, unconfined compression check, SEM, and pH check. Clayey soil samples were artificially contaminated using four different contaminant ratios (10%, 20%, 30%, and 50%) relative to the weight of water used for soaking for 24 hours. The results showed that the variations in chemical and physical characteristics were slight, as pH values gradually increased and stabilized after three weeks. From a mechanical perspective, resistance showed a significant increase, recording a ratio of 10,921% increase at 20% concentration after four weeks, followed by a further ratio of 2,851% increase at 50% concentration compared to uncontaminated soil. However, after 56 days, this significant increase began to decline, with resistance decreasing to a ratio of 51% at 20% concentration and a ratio of 5.15% at 50% concentration, compared to values recorded four weeks after the test. Scanning electron microscope (SEM) images also showed an increase in the ratio of voids with increasing contaminant concentration, indicating a negative impact of contamination on the soil microstructure.

The influence of iron powder content on the fresh and hardened properties of mortar

Bariza Boukni — 2025-06-30

The growing global waste problem, combined with the environmental impact of concrete production, necessitates innovative solutions to mitigate pollution, conserve resources, and enhance concrete performance. This research explores the potential of iron powder (IP) as a partial cement replacement in mortar. The study investigates the influence of iron powder on the fresh and hardened properties of mortar at seven replacement percentages: 1%, 2%, 3%, 4%, 5%, 10%, and 20% by weight. A comprehensive range of tests, including setting times, air content, density, flow time, compressive strength, and flexural strength, were conducted to assess the performance of the IP-modified mortars. The incorporation of iron powder into mortar mixtures significantly affected its properties. For replacement percentages greater than 3%, a slight enhancement in workability (3%) was observed. In terms of compressive strength, optimal performance was achieved with a 5% iron powder replacement (MIP5), surpassing that of the control mortar despite an increase in air content. Further increasing the iron powder content beyond 5% resulted in a modest decrease in compressive and flexural strengths, confirming that 5% is the optimal replacement percentage. This research provides significant practical implications, offering a viable and sustainable pathway for utilizing industrial waste, reducing landfill burden, conserving natural resources, and developing greener, high-performance construction materials.