In aggressive environments, including acidic environments, low and high-plasticity clays play an important role in transmitting and spreading dangerous pollution. Stabilisation of these types of soils can improve their characteristics. In this research, different ratios of two precursors with a low calcium percentage, for example, waste statiti-ceramic sphere powder (WS-CSP) and a high calcium percentage (e.g. ground granulated blast furnace slag [GGBFS], were employed to investigate the properties of soils with different plasticity indices [PIs]). Low and high-plasticity-stabilised and stabilised with 5 wt% Portland cement specimens were prepared and exposed to an acidic solution with a pH of 2.5 in intervals of 1, 3, 6 and 9 months. The long-term durability of specimens was evaluated using the uniaxial compressive strength test (UCS) and bending strength test (BS). Additionally, the microstructures of these specimens under various time intervals were analyzed using scanning electron microscopy and Fourier-transform infrared. According to the results, in an acidic environment, the reduction in UCS, BS, toughness and secant modulus of elasticity (E50) for low-plasticity-stabilised specimens and containing 100% WS-CSP was lower than that of other specimens. The Taguchi method and ANOVA were used to investigate the effect of each control factor on the UCS and BS.

Tractors are essential for many farming tasks but cause high vibrations that lead to operator discomfort and fatigue. This study examines how different tractor settings during tillage operations affect Hand-Arm Vibration (HAV). The settings tested were speed (0.6, 0.7, 0.8 m/s), draft setting (2, 4, 6 kN), and tillage depth (0.10, 0.12, 0.14 m), following ISO 5349-1:2004 standards. The Taguchi L27 array for designing the experiments, Response Surface Methodology (RSM) to see how different settings affect the results of HAV responses along the x, y, and z axes for each experiment. Experiments showed that vibrations were highest along the z-axis. Rotavation caused more HAV than harrowing and cultivation. As speed increased, daily HAV exposure also rose significantly. Analysis showed that speed and draft setting had a major impact on HAV levels. The study used different models to predict HAV, finding the quadratic model to be the most accurate. Optimal settings to minimize HAV were a speed of 0.8 m/s, draft setting of 2 kN, and tillage depth of 0.14 m. An artificial neural network (ANN) model also predicted HAV accurately with just a 2 % error. The findings suggest that the ANN model effectively predicts HAV under various tractor settings with constrain to the selected input setting. Relevance to the Industry: This research highlights the measures to reduce hand-transmitted vibration by optimizing the input (riding) parameters among tractor operators, which offers to improve the health and safety of users and reduce fatigue in actual farm conditions. In addition, the ANN model helps predict the HAV response under different input (riding) conditions. Ultimately, it is beneficial for the manufacturers and agriculture practitioners to optimize the tractor design and usage, ensuring safer and more efficient farm activities.

Calcium carbide residue (CCR), a calcium-rich industrial waste, shows promise in improving mechanical properties of weak soils when used alone or in combination with pozzolanic materials and alkaline activators. This study comprehensively investigated the mechanical performance and stabilisation mechanism of CCR, CCR-fly ash, and alkaline-activated CCR-fly ash on kaolin clay, aiming to clarify their differences in mechanisms, identify their limitations, and promote effective application. The contribution of CCR, fly ash, alkaline activator, and initial water content of soil on enhancing soil strength was quantitively assessed through signal-to-noise ratio and analysis of variance (ANOVA) based on the Taguchi method. The stabilisation mechanism of different CCR-based materials was investigated by assessing the morphological and mineralogical features of stabilised samples. Taguchi analysis revealed that the development of soil strength was primarily influenced by initial water content in the early curing stage, while the contribution of fly ash became larger over time. Variation in CCR content had a limited effect on soil strength across all curing periods, as indicated by low contribution values and low statistical significance in ANOVA. The microstructural analyses revealed a low degree of formation of C-S-H and CA-H gels in soil stabilised with CCR alone and CCR combined with fly ash, while alkaline activated CCR-fly ash stabilised soil exhibited the coexistence of C-A-S-H and N-A-S-H gels. Taguchi superposition model was effectively used to estimate compressive strength results and supported the determination of suitable CCR-based materials for specific strength requirements.

Expansive soils are known as geotechnically problematic soils and represent a significant challenge for both civil engineering and geotechnical applications. The primary issue with expansive soils is their susceptibility to moisture-induced volume changes, resulting in both shrinkage and swelling behaviors. This study presents a comprehensive investigation into optimizing the physical and strength properties of expansive soil through the use of cellulose-based fiber additives, namely bamboo fiber (BF), rice husk fiber (RHF), and wheat straw fiber (WSF). Various fiber dosages (5 %, 10 %, and 15 %) and sizes (75 mu m, 150 mu m, and 300 mu m) were employed in combinations to identify the optimal conditions and analyze the soil-fiber reinforcement mechanisms. The experimental design was leveraged by the Taguchi method to optimize conditions, focusing on key response factors such as the Atterberg limit test (PI, LL), free swell ratio (FSR), linear shrinkage (LS), and unconfined compressive strength (UCS) and statistical analysis for results were validated by Analysis of Variance (ANOVA). Additionally, cellulose content and water absorption capacity were assessed to confirm the suitability of cellulose-based fibers as soil stabilizers. Hence, the results demonstrate a substantial enhancement in both the physical and mechanical properties of the stabilized soil with the incorporation of cellulose-based fiber additives. Specifically, the Plastic Index (PI) improved by 85 % when using RHF fibers at a dosage and size of 15 % and 300 mu m, respectively. The Free Swell Ratio (FSR) witnessed improvement with WSF fibers at a dosage of 15 % and a size of 150 mu m. Linear shrinkage exhibited remarkable improvement, exceeding 95 %, with a combination of 15 % and 75 mu m fibers. Furthermore, the Unconfined Compressive Strength (UCS) values were improved by more than 100 % when using 15 % BF fibers with a size of 300 mu m. Therefore, the findings of the study highlight that cellulosebased additives as highly effective and sustainable alternatives for soil stabilization, surpassing the engineering performance of traditional soil stabilizers

To minimize the adverse impacts of cement production, introduce a natural resources as replacive cementitious material, and provide sustainable concrete, the present work identified a sub-class of zeolite soil with high SiO2 and low CaO contents, namely clinoptilolite. It is a widely spreaded soil, mechanically active, potentially ready to contribute in concrete pozzolanic reactions in a novelty manner. The mechanical activation modified the morphology and the structure of clinoptilolite to amorphous phases (e.g., hydroxyls losing bonding strength). To approach the goals, several dosages of clinoptilolite (0-20%) with and without silica fume (0-10%) contributed to the design of 567 concrete mixes, at three water-to-binder (w/b) ratios of 0.38, 0.42, and 0.45, the mixes were cured for 7, 28 and 90 days. Using the Taguchi L9 orthogonal array, 9 sets of optimum mix designs were derived out of 27 experiments and were optimized for mechanical strength tests. The experimental data and predicted results were compared and validated with a total accuracy of 90.84% (acceptable error levels). By increasing the curing age at the lowest w/b ratio, compressive strength (up to 56 MPa), Tensile strength (up to 3.9 MPa), and flexural strength (up to 7.0 MPa) were enhanced by both replacive materials (up to 30 wt%). However, long-term development (28, 90 days) is characterized by clinoptilolite, indicating a high pozzolanic reactivity in a lower w/b ratio attributable to its specific surface area and reactive SiO2 content. The experimental program and the high accuracy of the model showed that replacing OPC with clinoptilolite and SF is highly recommended in terms of sustainable concrete production, minimizing cement manufacturing impacts, and lowering the water consumption.