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The estimation of bearing capacity for shallow foundations in swelling soil is an important and complex context. The complexity is due to the unsaturated swelling soil related to the drying and humidification environment. Hence, a serious study is needed to evaluate the effect of swelling potential soil on the foundation bearing capacity. The purpose of this paper is to analyze the bearing capacity of a rough square foundation founded on a homogeneous swelling soil mass, subjected to vertical loads.

A proposed numerical model based on the simulation of the swelling pressure in the initial state, followed by an elastoplastic behavior model may be used to calculate the foundation bearing capacity. The analyses were carried out using the finite-difference software (FLAC 3 D) with an elastic perfectly plastic Mohr–Coulomb constitutive model. Moreover, the numerical results obtained are compared with the analytical solutions proposed in the literature.

The numerical results were in good agreement with the analytical solutions proposed in the literature. Also, reasonable capacity and performance of the proposed numerical model.

The proposed numerical model is capable to predict the bearing capacity of the homogeneous swelling soil mass loaded by a shallow foundation. Also, it will be of great use for geotechnical engineers and researchers in the field.

Intumescent coatings are nowadays a dominant passive system used to protect structural materials in case of fire. Due to their reactive swelling behaviour, intumescent coatings are particularly complex materials to be modelled and predicted, which can be extremely useful especially for performance-based fire safety designs. In addition, many parameters influence their performance, and this challenges the definition and quantification of their material properties. Several approaches and models of various complexities are proposed in the literature, and they are reviewed and analysed in a critical literature review.

Analytical, finite-difference and finite-element methods for modelling intumescent coatings are compared, followed by the definition and quantification of the main physical, thermal, and optical properties of intumescent coatings: swelled thickness, thermal conductivity and resistance, density, specific heat capacity, and emissivity/absorptivity.

The study highlights the scarce consideration of key influencing factors on the material properties, and the tendency to simplify the problem into effective thermo-physical properties, such as effective thermal conductivity. As a conclusion, the literature review underlines the lack of homogenisation of modelling approaches and material properties, as well as the need for a universal modelling method that can generally simulate the performance of intumescent coatings, combine the large amount of published experimental data, and reliably produce fire-safe performance-based designs.

Due to their limited applicability, high complexity and little comparability, the presented literature review does not focus on analysing and comparing different multi-component models, constituted of many model-specific input parameters. On the contrary, the presented literature review compares various approaches, models and thermo-physical properties which primarily focusses on solving the heat transfer problem through swelling intumescent systems.

The presented literature review analyses and discusses the various modelling approaches to describe and predict the behaviour of swelling intumescent coatings as fire protection for structural materials. Due to the vast variety of available commercial products and potential testing conditions, these data are rarely compared and combined to achieve an overall understanding on the response of intumescent coatings as fire protection measure. The study highlights the lack of information and homogenisation of various modelling approaches, and it underlines the research needs about several aspects related to the intumescent coating behaviour modelling, also providing some useful suggestions for future studies.

The purpose of this paper is to present synthesis protocol of hydrogel composed of Chitosan (CS) and Poly(ethylene glycol) (PEG) and establish an understanding of its thermal responsive behavior. It aims to prove the basic temperature sensing ability of a novel CS-PEG-based hydrogel and define its sensing span.

This study includes synthesis of CS and PEG-based hydrogel samples by first performing dissolution of both constituents, respectively, and then adding Glutaraldehyde as the cross-linking agent. It further includes proposed hydrogel’s swelling studies and dynamic behavior testing, followed by hydrogel characterization by Fourier transform infrared spectroscopy, X-ray diffraction and SEM. The last section focuses on the use of proposed hydrogel as a temperature sensor.

Detailed experimental results show that a hydrogel comprising of CS and PEG presents a thermally responsive behavior. It offers potential to be used as a temperature responsive hydrogel-based sensor which could be used in medical applications.

This research study presents scope for future research in the field of thermally responsive bio-sensors. It provides basis for the fabrication of a thermal responsive sensor system based on hydrogels that can be used in specific medical applications.

The extrudate swell phenomenon is analysed by solving, simultaneously, the Navier‐Stokes equations along with the continuity equation by means of a finite volume method. In this work, the planar jet flows of incompressible viscous Newtonian and power‐law fluids for Reynolds numbers as high as 75 are simulated. The method uses the velocity components and pressure as the primitive variables and employs an unstructured triangular grid and triangular or polygonal control volume for each separate variable. The numerical results show good agreement with previously reported experimental and numerical results. Shear thickening results in an increase in swelling ratio, while the introduction of surface tension results in a describes in swelling ratio.

In continuation to the previous work on copper (lignin/silica/fatty acids) (Cu-LSF) complex as a natural antioxidant/electrical conductivity agent for nitrile-butadiene rubber (NBR), this study aims to perform further investigations for NBR vulcanizates loaded with different concentrations of Cu-LSF complex, including swelling behavior and hardness properties, as well as evaluating their thermal stability via thermogravimetric analysis.

The behavior of Cu-LSF complex in NBR matrix was compared with that of the standard commercial antioxidants (2,2,4-trimethyl-1,2-dihydroquinoline/N-isopropyl-N′-phenyl-p-phenylenediamine [TMQ/IPPD]).

Results revealed that Cu-LSF complex can act as an effective reinforcing and hardening agent, with exhibiting fluid resistance, even when compared with the commercial antioxidants. In comparison with the previous studies on its Zn and Ca analogues and their behavior in different rubber matrixes, Cu-LSF complex showed higher values of hardness and less susceptibility for swelling, respectively. Moreover, Cu-LSF antioxidant activity becomes in accordance with the previous work.

The new Cu-LSF complex could be used as a green alternative to the commercial antioxidants (TMQ/IPPD) with introducing further advantages to the rubber matrix, such as hardening, fluid resistance and thermal stability.

Starch is the food‐reserve material of all higher plants, where it is stored in the form of characteristic, cold water‐insoluble particles known as starch granules. As starches are polymers of glucose, which are readily assimilated, they form an important source of nutritional energy in the human diet. Indeed, a very high proportion of the world's food energy‐intake is as starch, and cultivation of plant sources rich in this polysaccharide are widespread. 82% of all food crops are composed of cereals and starchy root‐crops.

Stimuli-sensitive poly (N-isopropylacrylamide-co-sodium acrylate) [poly (NiPAAm-co-SA)] hydrogels are prepared by free radical polymerization of N-isopropylacrylamide (NiPAAm) and sodium acrylate (SA) using N, N'-methylene bisacrylamide (BIS) as a crosslinking agent. The effects of SA content, crosslinking agent concentration and the pre-gel solution concentration on the swelling behavior of poly (NiPAAm-co-SA) hydrogel are investigated systematically. The results indicate that the swelling capacities increase with an increase in the amount of hydrophilic poly (sodium acrylate) anionic units, and thermo-sensitivity is weakened simultaneously. The effect of the pre-gel solution concentration on the swellabilities of poly (NiPAAm-co-SA) is more than that of the crosslinking agent concentration. Furthermore, the pH-sensitivity of the networks is also investigated, and it is found that the swelling behavior of poly (NiPAAm-co-SA) hydrogels obviously improves when the pH value is 5.

The purpose of this paper is to evaluate the possible use of oil shale as a soil stabilizing agent for expansive soils.

An experimental work has been fulfilled to investigate the influence of oil shale ash (OSA) on the geotechnical behavior of the expansive soil of Irbid, Jordan. Three swelling-shrinkage soils were considered in this study along with various percentages of OSA varying at 2, 4, 6, 8, 10 and 12 per cent by dry weight of the soil. A series of laboratory tests were conducted on the soil samples before and after mixing it with OSA. These tests were soil classification, Atterberg limits, compaction test, falling head permeability test, unconfined compression test, free swelling, swelling pressure and California bearing ratio (CBR) test.

Laboratory tests results indicated that OSA is effective in improving the texture and strength of the treated soil by reducing plasticity index, swelling potential and swelling pressure and moderately enhancing soil strength properties including the unconfined compressive strength (q_u), maximum dry unit weight (γ_d-max.) and CBR test.

OSA showed potential as a low-cost soil stabilizing agent for swell-shrink soils.

This study aims to investigate the swelling behavior, mechanical and thermal properties of ternary rubber blend composites prepared by melt blending based on carbon black (CB)-filled natural rubber (NR)/styrene-butadiene rubber (SBR)/nitrile butadiene rubber (NBR) blends, containing a variety of compatibilizers. Various compatibilizers, maleic acid anhydride (MAH), prepared emulsion and adhesion system (HRH) were used. A series of NR/SBR/NBR blends at a 30/30/40 blend ratio reinforced with 45 phr of CB were prepared using the master-batch method.

Thermal aging properties of the composites characterized by their aging coefficient and retention in tensile and elongation at break (E.B. %). Thermal degradation of ternary rubber blend composites based on melt blending has been studied using thermogravimetric analysis.

The swelling coefficient decreased with increased compatibilizer loading. Results also showed that the tensile strength and E.B. (%) decreased with aging over the entire aging period. Additionally, the addition of compatibilizers into the ternary rubber blend composite had slightly improved the thermal stability.

Interactions between the different components of blends at the interfaces have a high impact on the interfacial properties of the rubber blend.

Compatibilizers significantly improve the properties of the resulting composites with the loading of investigated compatibilizers because of the uniform dispersion of CB in the rubber matrix.

Using blends in the rubber industry led to the high-efficiency production of low-cost products.

The rubber blending has a significant positive effect on a wide range of applications such as structural applications, aerospace, military, packaging, tires and biomedical, so improving the compatibility of blends will make new materials suitable for new applications.

This study aims to investigate the behavior of the green biomass-derived copper (lignin/silica/fatty acids) complex, copper lignin/silica/fatty acids (Cu-LSF) complex, when incorporated into the nonpolar ethylene propylene diene (EPDFM) rubber matrix, focusing on its reinforcing and antioxidant effect on the resulting EPDM composites.

The structure of the prepared EPDM composites was confirmed by Fourier-transform infrared spectroscopy, and the dispersion of the additive fillers and antioxidants in the EPDM matrix was investigated using scanning electron microscopy. Also, the rheometric characteristics, mechanical properties, swelling behavior and thermal gravimetric analysis of all the prepared EPDM composites were explored as well.

Results revealed that the Cu-LSF complex dispersed well in the nonpolar EPDM rubber matrix, in thepresence of coupling system, with enhanced Cu-LSF-rubber interactions and increased cross-linking density, which reflected on the improved rheological and mechanical properties of the resulting EPDM composites. From the various investigations performed in the current study, the authors can suggest 7–11 phr is the optimal effective concentration of Cu-LSF complex loading. Interestingly, EPDM composites containing Cu-LSF complex showed better antiaging performance, thermal stability and fluid resistance, when compared with those containing the commercial antioxidants (2,2,4-trimethyl-1,2-dihydroquinoline and N-isopropyl-N’-phenyl-p-phenylenediamine). These findings are in good agreement with our previous study on polar nitrile butadiene rubber.

The current study suggests the green biomass-derived Cu-LSF complex to be a promising low-cost and environmentally safe alternative filler and antioxidant to the hazardous commercial ones.