Particle characteristics (particle shape and size), along with relative density, significantly influence the frictional characteristics and liquefaction behavior of granular materials, particularly sand. While many studies have examined the individual effects of particle shape, gradation, and relative density on the frictional characteristics and liquefaction behavior of sand, they have often overlooked the combined effects of these soil parameters. In this study, the individual effect of these three soil parameters on the strength characteristics (angle of internal friction) and liquefaction resistance has been quantified by analyzing the data available in the literature. A novel dimensionless parameter, the 'packing index (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\alpha $$\end{document}),' was developed to account for the bulk characteristics (relative density - RD) and grain properties (gradation, represented by the coefficient of uniformity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$C_u$$\end{document}), and particle shape represented by the shape descriptor regularity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho $$\end{document})) of the granular soils. Through statistical analysis, a power law-based equation was proposed and validated to relate the cyclic resistance ratio (CRR) and angle of internal friction (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\phi $$\end{document}) with the packing index. Finally, an approach to assess the liquefaction resistance was detailed considering the intrinsic soil parameters, aiming to bridge the gap between field observations and laboratory analysis to facilitate a comprehensive understanding of soil behavior under cyclic loading.

The rheological properties and creep dynamical behavior of the granular materials are significantly influenced by the packing fraction. The granular materials with a low packing fraction tend to transit from a solid-like to liquid-like state. The strain evolution and deformation characteristics of granular materials under different packing fractions are investigated by triaxial creep tests. The result indicates that a critical packing fraction exists for the granular system under specific external loading conditions, below which the system will be broken in a short period of time. Conversely, for packing fraction that exceeds the critical value, the granular material system exhibits logarithmic creep dynamics and eventually reaches a steady state. To characterize the creep behaviors of granular materials under dynamic loading, a state evolution model is introduced. The model is verified by combining the theoretical predictions with the experimental observations. Furthermore, parametric analysis is also implemented based on the introduced model. The results demonstrate that the model can capture the fundamental spatiotemporal evolution characteristics of granular materials which are subjected to dynamic loading conditions.

Concrete structures located in environments such as oceans, salt soils, and salt lakes are not only subjected to the sustained action of loads, but also to the erosive attack of sulphate ions at the same time, leading to changes in their mechanical properties. This paper focuses on the development of the mechanical properties of fly ash concrete over time, targeting axially compressed fly ash concrete components in a sulfate erosion environment. Under a stress level of 20 %, the paper takes into account factors such as fly ash contents of 25 %, 50 % and 75 %, loading ages of 28d, 90d and 120d, and sulphate solution concentrations of 2 %, 6 % and 10 %, respectively, conducting experimental research on the evolution of mechanical properties after the coupling effects of sustained load and sulfate erosion. Subsequently, the mechanism and law of evolution of axial compressive strength and modulus of elasticity of fly ash concrete after sustained loading coupled with sulphate erosion are analyzed. By using the concrete Compressible Packing Model (CPM) and the Triple-Sphere Model (TSM), along with a durability analysis of fly ash concrete under sustained loading, the calculation models of axial compressive strength, as well as the elastic modulus of fly ash concrete after the coupled action of sustained loading and sulphate erosion are established respectively. Finally, the model established in this paper is evaluated through data analysis using deviation analysis, the Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) methods, comparing it with existing models and experimental results. The research results show that, in terms of deviation analysis, the model established in this paper has a deviation of less than 1.5 % compared to the test data for elasticity modulus, and a deviation of less than 2 % compared to the test data for compressive strength. In terms of Root Mean Square Error (RMSE) and Mean Absolute Error (MAE), the model's errors compared to the experimental results for elasticity modulus and compressive strength are within 0.5. The comparison shows that the calculation results of the mechanical properties model of fly ash concrete constructed in this paper are in good agreement with the test data. The significance of the research lies in its ability to provide a theoretical basis for understanding the long-term performance development law of fly ash concrete structures in sulphate erosion environment.

Most of the world's railways are on ballasted track-a versatile and cost-effective support solution that can be traced back to the nineteenth century. In the twenty-first century, heavier and faster trains (freight and passenger) create higher loads and maintenance requirements. Ballast degradation becomes an important issue and solutions to increase time intervals between maintenance interventions are necessary. Some proposals involve the incorporation of elastic elements such as crumb rubber mixtures in the ballast. The crumb rubber reduces dilatancy and particle breakage. However, there is a lack of consensus on some key parameters. For example, the optimum percentage of crumb rubber in ballast is often given as 10%, which results in beneficial changes in the stiffness and energy absorption properties of ballast. However, some studies refer to 10% by volume, while others refer to 10% by weight. This leads to very different outcomes, as 10% by weight is nearly double 10% by volume of the soil particles. The paper analyses the influence of incorporating crumb rubber with two different sizes of particle, at 10% by weight and 10% by volume of mineral particles, into 1/3 scaled ballast. The addition of crumb rubber densifies the natural volumetric packing of 1/3 scaled ballast. The maximum (e(max)) and minimum (e(min)) void ratios decreased for all situations tested. This is explained in part by voids filling. Under cyclic loading, crumb rubber segregation was observed.

In this study, hydroxypropyl cellulose (HPC) was utilized as the raw material, with the addition of beta-cyclodextrin (beta-CD), citric acid (CA) as the crosslinking agent, and sodium hypophosphite (SHP) as the catalyst to produce hydroxypropyl cellulose/beta-CD composite films. The inclusion of beta-CD resulted in an increase in the tensile strength of the film, with the maximum value of 13.5 MPa for the 1 % beta-CD composite membrane. Additionally, after degradation in soil for 28 days, the degradation ability was significantly enhanced, with the 1.0 % beta-CD composite film exhibiting the highest degradation rate of 27.21 %. Furthermore, the water permeability of the composite membrane was improved with the addition of beta-CD. Specifically, when the beta-CD content was 1.0 %, the water vapor transmission reached its lowest point at 2,445 g* ( m 2 * 24 d ) - 1 ${({m}{2}\ast 24d)}{-1}$ . The findings demonstrated that the 1 % beta-cyclodextrin/hydroxypropyl cellulose composite film effectively preserved the freshness of strawberries, reducing the weight loss rate by 1.65 % compared to the control group. In conclusion, this research highlights the potential for preparing composite membranes using HPC and beta-CD crosslinking, thereby expanding the application of hydroxypropyl cellulose and beta-CD in food preservation.

A key and urgent scientific issue is how to characterize the complex intergranular contact state and mechanical behavior evolution of sand-fines mixed materials and then show how this state contributes to the static and dynamic properties of such materials. Both theoretical analyses and experimental data suggest that the mixes have different intergranular contact states as the fines content (FC) increases, and the mixed materials can be classified as sand -like, in -transition, or fines -like. The capability of the Rahman semi -empirical formula to predict the threshold fines content FCth-which distinguishes the regime of fines in sand (sand -dominated behavior) from that of sand in fines (fines -dominated behavior)-is verified using the basic material and mechanical properties of mixed materials from the literature. Developed from the method for determining the theoretical minimum void ratio, a new method that allows unified characterization of the critical intergranular contact state parameters FCin-min and FCin-max for in -transition soils is established based on the binary packing model, and FCin-min and FCin-max can be determined simply through explicit expressions that use some material physical indices of pure -sand and pure -fines materials. The proposed procedure offers significant advantages for evaluating the critical intergranular contact state and mechanical properties of sand-fines mixed materials in geotechnical engineering practice.

Roller Compacted Concrete Pavements (RCCP) are mostly designed by soil-compaction technique. However, the shortcomings associated with the soil-compaction method warrant a scientific way of designing RCCP mixtures based on the paste volume requirements considering the compactness and morphology of aggregates. To evaluate the optimum binder ratio (ratio of paste volume to the volume of void) for RCCP, several mixes were prepared following the particle packing approach by varying the binder ratio at a constant water-cement ratio (0.42). Fresh density, consistency, compactability, hardened density, and compressive strength were considered for binder ratio optimization. It was observed that there exists a linear relationship between the binder ratio and hardened properties up to a ratio of one; post this, a significant decrease in the considered hardened properties was observed. The results indicate that the RCCP mixtures could achieve higher strength and good workability with a binder ratio of 1.

The proliferation of single-use plastics has led to widespread pollution and ecological harm, prompting a concerted effort to develop sustainable alternatives. Among them, biocomposite plastic films have emerged as a promising solution for food packing applications. Herein, the preparation of polyvinyl alcohol (PVA) biocomposite films incorporating Clitoria ternatea (CT) flower extracts is reported. The obtained films are subjected to various analytical techniques. Fourier transform infrared spectroscopy analysis reveals the intense peak of hydrogen bonding at 3321 cm(-1) in the composite film. CT-PVA films possess less opacity and UV light-blocking capabilities. The PVA-CT films are examined for water absorption, UV barrier, soil degradability, and water-soluble properties, greater propensity to dissolve in water during the water absorption test is noticed. Enzymatic oxidation followed by hydrolysis of functional groups enhances the soil degradation rate in biocomposite films. Further, the colorimetric study of CT-PVA solution at different pH shows colored CT-PVA films. From the results and observations, the CT-PVA biocomposite film (8 mL) proves to be a promising candidate for utilization in the food industry as a packaging material.

The volumetric deformation of clayey soils, leading to a reduction in the bearing capacity and serviceability of pavements and building structures, is a major concern during their design, construction, and maintenance. Several approaches are often followed to mitigate the volume expansion and concomitant damage, including removal and replacement, moisture treatment with appropriate compaction protocols, and chemical treatment. During these treatment processes, the in-situ fabric is altered as the natural undisturbed soils are remolded and compacted. Hence, it is crucial to understand the effect of remolding on the volumetric characteristics of clayey soils. To investigate this effect, coefficient of linear extensibility (COLE) tests were conducted on both natural and remolded soil samples. The objective was to evaluate the impact of soil fabric modification on volumetric characteristics such as suction compressibility index (gamma h) and soil water-retention characteristics, i.e., the soil-water characteristic curve (SWCC) of clayey soils. Our findings indicated that remolded soils had approxi-mately 10% to 30 % higher gamma h-values than those of unaltered soils, which can be attributed to changes in porosity. Two distinct mechanistic models were developed using the packing theory concept to link the gamma h-value and SWCC of remolded and natural soils. Finally, an analysis was conducted to compare the potential vertical movement (PVM) of natural and remolded clay soils. This analysis revealed that the remolded soil fabric sub-stantially increased the PVM values, particularly for high-plasticity clay soils. This effect should be considered when assessing the impact of treatment that requires remolding, which substantially alters the soil structure and fabric.