The accumulation or landfill of lithium slag will contaminate the surrounding soil and water quality with residual sulfides and harmful elements, causing serious environmental hazards. This study aims to use Lithium slag (LS) as a sustainable alternative for silica flour (SF) in high-temperature cementing and examines the effects of this substitution on the microstructural and mechanical properties of cement pastes. The results show that an appropriate amount of LS can reduce the permeability of oil well cement and increase its high temperature compressive strength. Compared with pure paste (RS), the compressive strength of the sample replaced by 30 % LS increased by 87.8 % and the permeability decreased by 57.1 % after 28 days of high temperature curing. From the phase point of view, the samples supplemented with LS can form Xonotlite and Katoite with dense structure and high temperature stability. These hydration products can reduce the matrix porosity and permeability, increase the matrix density, and effectively improve the compressive strength of the cement pastes. In addition, the environmental effect analysis showed that the leaching toxicity and radioactivity of the sample did not exceed the standard requirements. This study provides a new direction for the sustainable utilization of LS resources, which not only combats the environmental pollution caused by LS accumulation, but also reduces the cost of cementing materials.

Silt soil is widely distributed in coastal, river, and lacustrine sedimentary zones, characterized by high water content, low bearing capacity, high compressibility, and low permeability, representing a typical bulk solid waste. Studies have shown that cement and ground granulated blast furnace slag (GGBFS) can significantly enhance the strength and durability of stabilized silt. However, potential variations due to groundwater fluctuations, long-term loading, or environmental erosion require further validation. This study comprehensively evaluates cement-slag composite stabilized silt as a sustainable subgrade material through integrated laboratory and field investigations. Laboratory tests analyzed unconfined compressive strength (UCS), seawater erosion resistance, and drying shrinkage characteristics. Field validation involved constructing a test with embedded sensors to monitor dynamic responses under 50% overloaded truck traffic (simulating 16-33 months of service) and environmental variations. Results indicate that slag incorporation markedly improved the material's anti-shrinkage performance and short-term erosion resistance. Under coupled heavy traffic loads and natural temperature-humidity fluctuations, the material exhibited standard-compliant dynamic responses, with no observed global damage to the pavement structure or surface fatigue damage under equivalent 16-33-month loading. The research confirms the long-term stability of cement-slag stabilized silt as a subgrade material under complex environmental conditions.

Red-bed mudstone from civil excavation is often treated as waste due to its poor water stability and tendency to disintegrate. This study proposes a sustainable approach for its utilization in controlled low-strength material (CLSM) by blending it with cement and water. Laboratory tests evaluated the fresh properties (i.e., flowability, bleeding rate, setting time, and subsidence rate) and hardened properties (i.e., compressive strength, drying shrinkage, and wet-dry durability) of the CLSM. The analysis focused on two main parameters: cement-to-soil ratio (C/S) and water-to-solid ratio (W/S). The results show that increasing W/S significantly improves flowability, while increasing C/S also contributes positively. Flowability decreased exponentially over time, with an approximately 30% loss recorded after 3 h. Bleeding and subsidence rates rose sharply with higher W/S but were only marginally affected by C/S. To meet performance requirements, W/S should be kept below 52%. In addition, the setting times remained within 24 h for all mixtures tested. Compressive strength showed a negative correlation with W/S and a positive correlation with C/S. When C/S ranged from 8% to 16% and W/S from 44% to 56%, the compressive strengths ranged from 0.3 MPa to 1.22 MPa, meeting typical backfilling needs. Drying shrinkage was correlated positively with water loss, and it decreased with greater C/S. Notably, cement's addition significantly enhanced water stability. At a C/S of 12%, the specimens remained intact after 13 wet-dry cycles, retaining over 80% of their initial strength. Based on these findings, predictive models for strength and flowability were developed, and a mix design procedure was proposed. This resulted in two optimized proportions suitable for confined backfilling. This study provides a scientific basis for the resource-oriented reuse of red-bed mudstone in civil engineering projects.

This study explores the dual application of Karpuravalli banana plant waste for sustainable material development, focusing on the extraction of wax from banana shoots and the creation of biodegradable packaging films from banana peel powder. Two extraction methods, refluxing and Soxhlet, were used to obtain wax from mature and third leaf shoots, with Soxhlet yielding 4% wax and refluxing producing 2%. The wax exhibited properties similar to commercial natural waxes, with GC-MS analysis revealing a predominant C23 fatty acid. Biodegradable films were developed using banana peel powder, corn starch, glycerol, and wax as a moisture-resistant coating. The wax-coated films showed increased thickness and moisture resistance but decreased transparency and mechanical properties, such as tensile strength and elongation. Both film types achieved over 98% biodegradation in soil. This research highlights the potential of utilizing banana plant by-products for eco-friendly packaging solutions, demonstrating that while the wax improves moisture resistance, further optimization is needed to enhance mechanical performance, thus contributing to sustainable material development from agricultural waste.

Expansive soils swell when wet and shrink when dry, causing differential settlements that can lead to structural failures in roads and buildings. In cases where these soils cannot be avoided, improving their stability is essential. This study investigates the use of two binders, ground granulated blast-furnace slag (GGBS) and bagasse ash (BA), byproducts of steel and sugarcane processing, respectively, to reduce soil swelling and enhance stability by assessing the mechanical behavior of reinforced expansive soil. To evaluate the behavior of reinforced expansive soils, tests such as Atterberg limits, compaction, swelling potential, and direct shear were conducted. Results indicated that as reinforcement levels increased to an optimal threshold (3 % GGBS and 12 % BA), the optimum moisture content rose, while maximum dry unit weight generally decreased. A 15 % increase in moisture content and a 3.16 % decrease in maximum dry unit weight were observed with reinforcement. Cohesion decreased by 27 % in soaked conditions and 31 % in unsoaked, while the angle of internal friction rose by 106 % and 111 %, respectively, at the maximum reinforcement threshold. These additives also improved shear strength, reduced swelling potential, and lowered plasticity index, shifting the soil behavior from clay-like to silty. The results show that bagasse ash and GGBS effectively enhance soil properties and provide a sustainable solution for soil stabilization in construction.

Natural stones are materials with distinct properties that are becoming increasingly popular because of their accessibility, performance, and decorative qualities. In the construction industry, igneous, sedimentary, and metamorphic rock types are frequently used, particularly in landscaping, sculpture, and ceramic production. These wastes are categorized in various forms, such as dust or fines, aggregates, larger pieces of stone, damaged blocks or slabs, and stone slurry. Waste has a significant impact on soil, water, air, and biological resources if problems that arise during and after operations are not properly addressed. In this study, the operating wastes produced during the production of & Ccedil;an Stone, which is defined in the literature as rhyolitic tuff, and has mineral deposits in & Ccedil;an, Turkey, were used as components in recipes created with ceramic triaxial blend systems. The main objective is to eliminate the environmental issues brought on by the accumulation of this waste while also enabling the use of a by-product that has a wide range of applications in various industrial sectors. The chemical compositions of the waste which are added up to 60% into the glaze recipes and raw materials used in recipes were determined by XRF analysis. Among the glaze recipes produced, 6glaze compositions were selected for characterization tests. XRD, SEM, hot stage microscope and spectrophotometer devices were used to characterize the produced glaze samples. Wastes were obtained from & Scedil;ahin Mining Company (& Ccedil;an-Turkey) and included in the formulations of ceramic glazes. Transparent glazes in color tones ranging from light brown to dark brown were obtained in the samples fired at 1200 degrees C.

Millions of PET bottle wastes occur in the world. These wastes are used as additives in different ways in solid form in many areas However, using PET bottle waste in solid form limits their usability in some areas (geotechnics, building materials). In this study, the effect of liquefied PET bottle waste(LPBW) on some physical and mechanical properties of fine-grained soil was investigated. For this purpose, Atterberg Limits (wL, wP) and unconfined compressive strength tests were carried out with the samples prepared by adding different ratios (5%, 10%, 15% and 20%) to the mixing liquid of the fine-grained soil, which was turned into viscous liquid PET bottle wastes. From the results of the experiments carried out in the laboratory, it has been shown that adding liquefied PET bottle waste material to the mixing water ata rate of up to 5% increases the unconfined compressive strength. In addition, it was determined that the workability of fine grained soils increased with the increase of liquefied PET bottle waste added to the mixing water.

Swelling-shrinkage deformation of expansive soils is the primary governing factor for development of the crack network, which is intimately associated with the bearing capacity and the structural integrity of the soil body. To suppress the swelling-shrinkage characteristic, sintered red mud was utilized as a curing agent to stabilized expansive soil, and the physical property testing phase consisted of compaction tests, Atterberg limit tests and pH tests to derive patterns on the physical and mechanical properties of the expansive soil influenced by the incorporation of red mud. The principal engineering property tests include unconfined compressive tests, one-dimensional swell tests, desiccation-induced crack study and micro-structure analysis by scanning microscopy techniques. The test findings demonstrate that even red mud would somewhat weaken the strength, but restrict the plasticity and successfully prevent swelling-shrinkage deformation of expansive soils. Such an effect is positively correlated with the red mud content. When the content reaches 20%, the crack ratio reduction exceeds 40%, the swelling deformation are reduced by about 20%, and the unconfined compressive strength higher than 500 kPa with dry density of 1.6 g/cm3. The stabilization of expansive soils with red mud effectively increases the structural integrity of the soil layers and the safety of constructions to offer guidance for environmentally friendly construction in expansive soil areas.