Biogrouting, a method to enhance soil properties using microorganisms and mechanical techniques, has shown great potential for soil improvement. Most studies focus on small sand columns in labs, but recent tests used 0.5 m plastic boxes filled with sand stabilized with microorganisms and fly ash. The experiments, conducted over 30 days, applied injection and infusion methods with microbial fluids, maintaining groundwater levels to simulate field conditions. Mechanical properties were analyzed through unconfined compressive strength (UCS) tests on extracted samples. Researchers also assessed calcium carbonate distribution and shear strength. Results showed water saturation significantly influenced vertical stress (qu), while UCS correlated with the permeability of sand containing varying calcium carbonate levels. Bacillus safensis, a resilient bacterium used in this process, can withstand extreme conditions. After completing its task, it enters a dormant state and reactivates when needed. The bacteria produce calcium carbonate by binding calcium with enzymes, which cements soil particles, enhancing strength and stability. center dot Testing enzymes on microbes and natural soil center dot Installation settings for drip tools using infusion center dot Soil resistance testing after stabilization using UCS

Soil is one of the construction materials used in civil works projects. The soil of the subgrade and its strength are critical for the construction of pavement. Soil improvement is usually necessary if the soil is weak. In order to increase its strength, improving the soil strength may reduce the cost and thickness of the pavement structure, and the main objective of this study is to add bitumen to the soil to improve its quality, the main objective of this study is to add bitumen to the soil to improve its quality. Bitumen mixtures of (2%, 4%, 6%, and 8%) The tests in this study included physical and mechanical properties of soil, Compaction, Atterberg limit, and CBR test without and with soaking and unconfined compressive strength (UCS). The results showed that the use of bitumen led to an increase in the maximum dry density and a decrease in the optimum water content at the ratios of 8%. The results also showed that the CBR values increased at 8%, while the unconfined compressive strength decreased at 8% addition. This study concluded that the use of bitumen improved the properties of the expansive soil, and this type of soil can be used in road works without causing problems in the future.

The increasing environmental impact of traditional cement production necessitates the exploration of sustainable alternatives in construction materials. This paper investigates corncob ash (CCA), an agro-waste by-product, as a viable substitute for cement in several construction and building material applications such as concrete, masonry, geopolymer materials, and soil stabilization. A comprehensive review of existing literature reveals that CCA enhances the mechanical properties of these materials, such as compressive strength and durability, and significantly reduces the carbon footprint associated with conventional cement production. The findings indicate that incorporating CCA improves workability and resistance to aggressive environmental conditions, positioning it as a promising material for sustainable construction. Furthermore, the paper identifies gaps in current research, particularly concerning long-term performance and standardization of testing methods. Future research directions are proposed, including optimization of processing techniques, life cycle assessments, and real-world applications, to fully leverage the potential of CCA in promoting environmentally friendly construction practices. Overall, this study underscores the critical role of CCA in advancing sustainability within the construction industry.

In response to the environmental challenges posed by conventional expansive soil stabilization methods, this study investigates the low-carbon potential of industrial by-products-cement kiln dust (CKD) and calcium carbide slag (CCS)-as sustainable stabilizers. A comprehensive series of laboratory tests, including compaction tests, free swelling rate measurements, unconfined compressive strength (UCS) evaluations, and scanning electron microscopy (SEM) analyses, were conducted on expansive soil samples treated with varying dosages in both single and binary formulations. The results indicate that the binary system significantly outperforms individual stabilizers; for example, a formulation containing 10% CKD and 9% CCS achieved a maximum dry density of 1.64 g/cm3, reduced the free swelling rate to 22.7% at 28 days, and reached a UCS of 371.3 kPa. SEM analysis further revealed that the enhanced performance is due to the synergistic formation of hydration products-namely calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H)-which effectively fill interparticle voids and reinforce soil structure. These findings demonstrate that the dual mechanism, combining rapid early-stage hydration from CCS with sustained long-term strength development from CKD, offers a cost-effective and environmentally sustainable alternative to traditional stabilizers for expansive soils.

This study investigates the sustainable use of seabed dredged sediments and water treatment sludges as construction materials using combined dewatering and cement stabilization techniques. Dredged sediments and water treatment sludges, typically considered waste, were evaluated for their suitability in construction through a series of dewatering and stabilization processes. Dewatering significantly reduced the initial moisture content, while cement stabilization improved the mechanical properties, including strength and stiffness. The unconfined compressive strength (UCS), shear modulus, and microstructural changes were evaluated using various analytical techniques, including unconfined compression testing, free-free resonance testing, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results show a direct correlation between reduced w/c ratios and increased UCS, confirming the potential of treated sludge as a subbase layer for roads and landfill liners. A chemical analysis revealed the formation of calcium silicate hydrate (CSH) and ettringite, which are critical for strength enhancement. This approach not only mitigates the environmental issues associated with sludge disposal but also supports sustainable construction practices by reusing waste materials. This study concludes that cement-stabilized dredged sediments and water treatment sludges provide an environmentally friendly and effective alternative for use in civil engineering projects.

The rising demand for housing, propelled by population growth, calls for affordable and reliable construction materials. Compressed Stabilized Earth Blocks (CSEB), an environmentally friendly construction material, serves as a potential solution. The clay soil retrieved from the Olifantsfontein Resource Facility, previously unused and occupying valuable space, was repurposed to produce CSEB, aligning with the company's waste reduction commitment. Soil analysis following South African National Standards (SANS) and American Society for Testing and Materials (ASTM) guidelines, revealing poorly graded sand with silt and clay. River sand was chosen based on particle packing theory to achieve a well graded PSD. Three mixtures with varying clay and river sand proportions, while maintaining a constant cement content of 5%, were prepared. Optimum moisture content was determined through trials with different moisture levels. A compressive strength test, both dry and wet, along with a water absorption test, were conducted to evaluate the brick's performance under variable conditions. Results showed that increasing clay content improved compressive strength, classifying the bricks as load-bearing. The study's compressive strength test results ranged between 3-5 MPa, with dry compressive strength outperforming wet compressive strength. On average, the three mixtures exhibited a water absorption of 11.31%, although mix designs with varying clay content showed different average water contents due to the water-absorption properties of cement and the water-holding capacity of clay. Overall, the findings demonstrate the potential of Olifantsfontein clay as a sustainable construction material for meeting the increasing demand for housing.

Although natural fibers (NFs), among which animal fibers (AFs) are found, have been used for millennia as reinforcement scheme of some construction materials (CMs), it is not until recent decades when scientific studies have been carried out to quantitively evaluate the impact of adding NFs into CMs, but with a special focus on vegetal fibers (VFs) over AFs. Nevertheless, there have been several studies addressing the use of AFs in different CMs and, therefore, the need of a systematic review study is evident. To contribute to this research gap, this paper presents a comprehensive review study addressing available scientific information of different types of AFs (e.g., sheep wool fibers (SWFs), chicken feathers fibers (CFFs), human hair fibers (HHFs), pig hair fibers (PHFs), silk fibers (SFs), and dog hair fibers (DHFs)) and also their use in four specific different CMs matrices (i.e., cementitious, gypsum, soil and polymer matrices). This comprehensive search was conducted in Web of Science and Science Direct, two of the largest and more prestigious scientific databases, using specific keywords and Boolean operators and the selection of the papers was based on the provision of enough quantitative information of the mixtures (e.g., specific characteristic and dosages of AFs and matrix used) as well as experimental findings. As a result of this study, organized, summarized and sufficient information is provided to support the positive use of AF as reinforcement scheme to improve some physical/thermal/mechanical/ damage/durability properties of CMs by taking advantage of the abundance of these resources worldwide. Moreover, the use of AFs might also provide environmental benefits and cost reductions, which are global objectives within the construction sector. Finally, this review study found that there are still several research gaps in the use of particular AFs (e.g., DHFs) as well as combinations between the AFs and the CMs addressed in this study (e.g., effects of PHFs in polymer matrices) and these gaps are recommended as future studies.

Using grout in construction and ground improvement has been common in various industries and construction projects. However, conventional grouts often need to be improved for their composition, durability, and environmental impact. Recently, there has been increased interest in exploring alternative solutions that are more sustainable and environmentally friendly. This comprehensive review aims to unravel the limitations of conventional grouts when exploring the potential of emerging biogrout technologies to achieve environmental sustainability in ground improvement. This review begins by examining the characteristics and limitations of traditional grouts, which highlights challenges such as inadequate durability and adverse environmental impacts. Then, the focus shifts toward emerging biogrout technologies, which harness the power of microorganisms to enhance soil stabilization. The principles, applications, and benefits of biogrout technologies are discussed thoroughly, along with case studies that showcase their successful implementation. A key aspect of this review is to highlight the environmental sustainability of biogrout applications in various civil engineering projects. Life cycle analyses (LCAs) are conducted to assess the environmental impacts of conventional grout, which sheds light on their drawbacks. In contrast, the environmental benefits and challenges that are associated with biogrout technologies are examined, which provides a comparative analysis between the two approaches. This review concludes by presenting prospects and challenges in this field. It discusses advances in conventional grout formulations to address their limitations and strategies to enhance the environmental performance of biogrout technologies. In addition, integrating sustainability principles into grouting practices is emphasized to achieve long-term environmental sustainability in ground improvement projects. Overall, this comprehensive review could contribute to the advances in sustainable ground improvement practices by providing insights into the limitations of conventional grouts and exploring the potential of emerging biogrout technologies. It could be a valuable resource for practitioners and researchers who seek sustainable solutions in ground improvement that align with environmental stewardship and sustainable development goals.

Drilling-waste management is of great importance in the oil and gas industry due to the substantial volume of multi-component waste generated during the production process. Improper waste handling can pose serious environmental risks, including soil and water contamination and the release of harmful chemicals. Failure to properly manage waste can result in large fines and legal consequences, as well as damage to corporate reputation. Proper drilling-waste management is essential to mitigate these risks and ensure the sustainable and responsible operation of oil and gas projects. It involves the use of advanced technologies and best practices to treat and utilize drilling waste in an environmentally safe and cost-effective manner. This article describes a feasibility study of four drilling-waste management options in the context of the Khanty-Mansi Autonomous Okrug of Russia. For ten years of the project life, the NPV under the base scenario is equal to RUB -3374.3 million, under the first scenario is equal to RUB -1466.7 million, under the second scenario is equal to RUB -1666.8 million and under the third scenario is equal to RUB -792.4 million. When considering projects, regardless of oil production, the project under the third scenario pays off in 7.8 years and the NPV is RUB 7.04 million. The MCD and MCV parameters were calculated to be 106 km and 2290 tons, respectively. Furthermore, the study estimates the ecological damage prevented and the environmental effect of each option. Quantitative risk assessments, conducted through sensitivity analysis, reveal that the fourth option, involving the conversion of drilling waste into construction materials, emerges as the most economically feasible. The study also evaluates the interaction between business and government and analyzes the current situation in the sphere of drilling-waste management, concluding with concise recommendations for both companies and official bodies.

The need to build a long-term or even permanent base is now a significant concern with the development of the exploration of extraterrestrial celestial bodies. Sulfur concrete was first proposed as a new building material in the 20th century. Recently, sulfur concrete has attracted much interest, as sulfur is considered one of the most accessible resources on the Moon and Mars, thanks to the in-situ resource utilization methodology. In addition, sulfur concrete is one of the most promising building materials for improving terrestrial sustainability or extraterrestrial exploration. So far, reviews have only focused on developing sulfur concrete and extraterrestrial building materials. This review paper summarizes the history of sulfur concrete development and different modified sulfur concretes. Previous research on extraterrestrial building materials is also reviewed. The unique advantage of sulfur concrete as an extraterrestrial material is justified, as no water is used during mixing. Lunar and Martian soil simulants are also examined as possible aggregate types. Finally, further improvements are proposed to broaden the application of sulfur concrete and the corresponding treatments. The possibility of recyclability and circularity is discussed from a sustainable development point of view. This review article provides readers with a detailed overview of sulfur concrete and its history, why it is more promising and accessible as an (extra)terrestrial building material, the challenges of its future application, and corresponding treatments to overcome the obstacles.