Search Results (754)

There is increasing interest in protein-enriched foods and in the valorisation of by-products from the agri-food sector. This study investigated the incorporation of by-products derived from texturised pea protein production into high-protein bread formulations. Wheat flour was partially replaced (10%) with different protein sources (gluten, pea protein isolate, pea protein concentrate, and two types of texturised by-products, T60 and T80). In a subsequent trial, blends of gluten with a by-product (T60) or with pea protein concentrate were evaluated at replacement levels of 10, 20 and 30%. Dough mixing properties and bread quality attributes (specific volume, texture and colour) were assessed. All protein sources increased water absorption. Gluten and the protein concentrate also increased kneading time. Gluten and the by-products increased the specific volume of the breads and reduced crumb firmness, whereas the isolate showed the opposite effect. The incorporation of gluten–T60 blends at 30% significantly increased dough water absorption, enhanced specific volume (by more than 80%), reduced crumb firmness, and improved elasticity and cohesiveness compared with the control, while doubling the protein content. However, achieving these improvements delays dough development. These results demonstrate the potential of texturised pea protein by-products as functional ingredients in breadmaking, enabling the development of nutritionally enriched products with favourable technological performance. Full article

This work deals with a practical method of using crumb rubber resulting from waste tires to produce modified bitumen via a wet mixing method for road construction in Iraq. Due to wide variation in temperatures and over-loading traffic in Iraq, rutting deformation is the most observed structural pavement problem. Also, tire wear and tear are higher in Iraq than in other countries due to high temperature and dry weather most of the year, which makes considerable amounts of waste tire piles easily accessible. Utilizing this waste material could be crucial to the environment and economy of the country, as well as to the sustainability of resources. Using waste tire materials as bitumen modifiers in the production of hot mix asphalt is a widely practiced experiment, although it is applied differently depending on the weather, type of bitumen used, and its availability. In the methodology of this research, it is suggested to modify asphalt grades 60/70 by a certain amount of crumb rubber (5–20%). The modified asphalt and asphalt grade 40/50 were used in preparing two types of asphalt concretes to examine their volumetric properties and evaluate their rutting behavior. The results for both mixtures were compared to the Iraqi General Specifications for Roads and Bridges (SORB/R9). The findings showed significant improvements in Marshall stability and flow, as well as in the percentages of voids satisfied in the modified mixture. After using rubberized asphalt in the mixture, the rutting depth was recorded below 20 mm and decreased by 30% and 26% at temperatures of 40 °C and 60 °C, respectively, compared to the controlled mixture. Full article

Crumb rubber-modified asphalt concrete (CMAC) has gained increasing attention as a sustainable pavement material capable of improving mechanical performance while utilizing waste tire resources. This study investigates the rutting resistance and fatigue behavior of CMAC using a combined experimental and mechanistic–empirical modeling approach. Asphalt mixtures containing 0–25% crumb rubber by binder weight were prepared and evaluated through Marshall stability and indirect tensile fatigue tests, whereas Fourier-transform infrared spectroscopy (FTIR) was used to examine binder–rubber interactions. The results indicate that crumb rubber significantly influences both the volumetric and mechanical properties of asphalt mixtures. Mixtures containing 10–15% crumb rubber exhibited optimal performances, achieving up to 36% higher Marshall stability and improved fatigue life compared with conventional asphalt mixtures. FTIR analysis revealed that rubber particle swelling and limited chemical interactions enhanced binder elasticity and improved binder–aggregate compatibility. However, excessive rubber content (≥20%) resulted in reduced stability owing to increased binder absorption and decreased effective binder film thickness. A mechanistic–empirical model incorporating viscoelastic, viscoplastic, and fatigue damage parameters successfully reproduced the experimental trends and identified the same optimal rubber content range. The findings demonstrate that CMAC with a moderate rubber content can enhance pavement durability and structural performance while promoting environmentally sustainable road construction through the reuse of waste tires. Full article

While rubberized asphalt with a crumb rubber content of 20% to 40% can improve asphalt performance, it also faces prominent issues such as increased construction viscosity and intensified fume emissions. Currently, systematic studies on high-content deodorized rubberized asphalt across different preparation temperatures remain insufficient, particularly regarding the synergistic optimization of performance enhancement and fume emission control, including gaseous pollutants and particulate matter. To address this, deodorized crumb rubber (G-CR), a surface-treated crumb rubber produced by coating with a deodorizing agent, was introduced in this study and blended with base asphalt to prepare deodorized rubberized asphalt (G-CRA). Through laboratory binder tests, the coupled effects of crumb rubber content and preparation temperature (170–200 °C) on the conventional properties, rheological characteristics, and fume emissions of G-CRA were systematically analyzed. The results show that at 30% crumb rubber content and 190 °C preparation temperature, the asphalt binder achieves an optimal balance among penetration, ductility, and softening point, along with significantly improved high-temperature stability and aging resistance. Compared to conventional crumb rubber asphalt (CRA, without deodorant treatment), G-CRA achieves a significant reduction in fume emissions, with SO₂ reduction reaching up to 81%. This study demonstrates that deodorized crumb rubber can effectively synergize performance enhancement and gaseous emission control under high-content conditions, providing laboratory-level data support for the development of environmentally friendly rubberized asphalt. Full article

Commercially produced gluten-free bread has gained popularity over the past decade. However, it often struggles to match its gluten-containing counterparts in terms of nutritional aspects, appearance, texture, and consumer acceptability. In this study, we aimed to optimize a novel gluten-free formulation based on tapioca starch and red lentil flour using a D-optimal mixture design. According to our findings, the swelling power and oil-holding capacity of the blended flour increased with the proportion of red lentil flour. The volume of bread loaves with 15% red lentil flour and 15% or 30% tapioca starch was close to that of the control bread. The addition of lentil flour tended to reduce the springiness of the experimental bread crumb, while the hardness was lower for the experimental sample with 15% lentil and 30% tapioca starch. The predicted glycemic index of the bread samples ranged from 70 to 87, and the sample containing 30% tapioca and 30% red lentil flour achieved the lowest score. Finally, the optimized gluten-free bread formulation showed lower hardness, pore density, and predicted glycemic index, and higher volume compared to the control bread sample, demonstrating that it is possible to improve gluten-free baked goods without compromises. Full article

This study examines the compressive behavior and analytical modelling of natural and rubberized concretes (RuC) confined with low-cost glass chopped-strand mat (GCSM) jackets. A total of forty-two cylindrical specimens were tested under axial compression to assess the influence of rubber particle size, confinement configuration, and the number of GCSM layers. The RuC mixes were prepared by replacing 20% of fine aggregate by volume with crumb rubber of two size fractions: coarse (2.0 mm, retained on #10 sieve) and fine (0.425 mm, retained on #40 sieve). Both full- and strip-wrapping schemes were applied using two, four, and six layers of GCSM. The results demonstrated that GCSM jackets significantly enhanced the mechanical performance of both NAC and RuC specimens. Full wrapping provided the highest confinement efficiency, increasing compressive strength by up to 115% for NAC and 90% for RuC, while the ultimate axial strain increased by more than 1300% compared with unconfined specimens. Strip wrapping also improved performance, producing strength gains of 25–45% and strain increases of 250–500%. Analytical stress–strain models were developed through regression analysis, showing strong correlation with the experimental results (R² = 0.80–0.99). The proposed GCSM jacket system demonstrates high potential as a sustainable and economical alternative for strengthening and retrofitting rubberized concretes, offering improved ductility and energy absorption while supporting circular material utilization. It is noted that the confinement ratio, size of rubberized aggregates, and their percentage replacement of rubberized aggregates should be consistent with the values used in this work in order to use the proposed analytical expressions. Full article

A sustainable way to recycle used tires and improve the functionality of asphalt pavements is through the use of crumb rubber modified asphalt (CRMA). However, its application during high-temperature construction raises environmental and occupational health concerns due to the release of significant quantities of odorous and potentially harmful gases. Therefore, this study selected α-Amyl cinnamic aldehyde (ACA) as a deodorant and added it to CRMA at proportions of 0.5%, 1.0%, 1.5%, and 2.0% to prepare DCRMA. A number of common tests, such as softening point, ductility, penetration, Brookfield rotational viscosity, and segregation analysis, were used to evaluate the basic characteristics of the modified asphalt. A self-developed asphalt fume monitoring device was used to quantitatively analyze the changes in VOCs, H₂S gas concentration, and solid particle content in the asphalt fumes to assess the deodorization effect of ACA on CRMA. Furthermore, the deodorization mechanism of ACA on CRMA was explored in depth using microscopic methods, such as fluorescence microscopy (FM) and Fourier transform infrared spectroscopy (FTIR). The findings demonstrated that ACA can increase the softening point and viscosity of CRMA while decreasing its penetration and ductility. The storage stability was optimal at a 1.0% ACA addition. Additionally, as the ACA content increased, the concentrations of VOCs, H₂S gas, and solid particles in the asphalt fumes continued to decrease. FM results indicated that when the ACA content did not exceed 1.0%, it promoted the swelling degree of CR in the asphalt. FTIR results showed that ACA can reduce the characteristic peak intensity of CRMA. This study offers important technical references and practical support for the environmentally friendly use of CRMA. Full article

Crumb rubber concrete (CRC), as a heterogeneous multiphase composite material composed of coarse aggregate, rubber particles, cement mortar, pores, and other constituents, is frequently regarded as a homogeneous material in engineering applications. This study employs numerical homogenization to compute equivalent mechanical parameters for CRC. By establishing a two-dimensional parametric random aggregate model combined with Monte Carlo simulations and finite element computations, it systematically analyzes the influence of rubber content (0%, 5%, 10%, 15%) and specimen size (50–150 mm) on CRC’s macroscopic equivalent elastic modulus. The research reveals that stable homogenization results, usable as macroscopic equivalent material parameters, are attained when the Representative Volume Element (RVE) size of the CRC model is ≥5 times the maximum aggregate particle size (dₘₐₓ). The equivalent modulus E decreases rapidly initially with increasing size, followed by a decelerated decline toward stabilization. A predictive model based on the fitted formula ln Eᵣ = kᵣ ln L + bᵣ (where Eᵣ denotes reduced modulus) enables elastic modulus prediction for large-scale components up to 600 mm. This study elucidates the macro-mesoscopic linkage mechanism governing CRC’s equivalent elastic parameters, providing a theoretical foundation for engineering structural design. Full article

The use of resource-saving technology in road construction material production is a current problem, the solution of which will allow us to increase the environmental and economic efficiency of the road construction industry. Nowadays, secondary raw materials are widely used in highway construction, obtained both from the waste of old road construction materials and collected from other industries. During asphalt production, up to 90% of raw materials can be replaced by reclaimed asphalt pavement (RAP). This technology requires residual binder modification to reduce the negative impact on the technological and operational asphalt concrete properties. On the other hand, the use of rubber crumbs or granules obtained from the disposal of old car tires in asphalt–concrete mixtures is widespread. However, some types of car tires cannot be used as raw materials to produce an effective modifier. Truck tires and tires from special vehicles are suitable for use as a modifier for asphalt–concrete mixtures. Tires designed for passenger cars do not contain enough polymer. As an experiment on asphalt–concrete mixture production using secondary resources only, a testing facility was developed. The testing facility uses hot gas obtained by burning automobile tires in a special oven as a heat source. Rubber residues from the recycling of automobile tires are used as fuel, which cannot be used to produce rubber powder or granules. RAP obtained by cold milling of the pavements of city and public roads was used as the object of the research. When studying the characteristics of the asphalt–concrete-mixture-based binder, it was found that the sulfur compounds present in the composition of hot gases change the properties of the binder, leading to a serious deterioration in the technological characteristics of asphalt–concrete mixtures. The asphalt–concrete mixture obtained during RAP processing is characterized by a narrow temperature range in which it can be laid and compacted to the required density values. After laying the pavement, quality control revealed a significant variation (the number of air voids ranged from 0.8 to 5.5%) in the average density of samples taken from the compacted layer. In addition, there were significant violations of the longitudinal evenness of the finished coating. Experiments were carried out to extract the binder from asphalt–concrete mixtures before and after regeneration. The physico-mechanical and rheological characteristics were studied and qualitative analysis of the binder was realized by IR spectroscopy. The data obtained allow us to establish the mechanism of how sulfur-containing gases influence the bitumen binder’s properties in asphalt mixtures. Additionally, the features of thermo-oxidative degradation occurring during the hot recycling of asphalt–concrete mixtures were established. A justification is also given for the need to use anti-aging modifiers to restore the properties of the residual binder. Full article

Modern diets often provide insufficient health-promoting nutrients, prompting the development of enriched staple foods. This study investigated the impact of incorporating germinated spelt (Triticum spelta), naked oat (Avena nuda), and buckwheat (Fagopyrum esculentum) seeds at 30% and 60% levels on the nutritional, technological, and sensory properties of wheat bread. Liquid chromatography–mass spectrometry (LC–MS/MS) analysis verified the successful transfer of grain-specific bioactive compounds into the dough and bread matrix—benzoxazinoids (BOA, MBOA) from spelt, avenanthramides (AVN A, B, C) from oats, and flavonoids (e.g., rutin, vitexin, orientin) from buckwheat—emphasizing both free and bound metabolite fractions. Multigrain breads exhibited a complementary phytochemical profile. The antioxidant properties of the enriched breads were markedly enhanced, with germinated buckwheat providing the most pronounced increase. Analysis confirmed a significant increase in dietary fibre content proportional to the level of germinated grain addition, with almost double the content in 60% multigrain bread. Texture analysis indicated that the control crumb exhibited the greatest relative firming over 48 h during storage. Sensory evaluation showed that all of the enriched breads received high acceptability scores (>18/20). The incorporation of germinated seeds effectively enhances the nutritional value of bread, offering a promising strategy for developing health-promoting bakery products. Full article

To evaluate the respective contributions of the crumb rubber (CR) particle effect (PE) and the CR–asphalt interaction effect (IE) to the high-temperature rheological performance of crumb rubber modified asphalt (CRMA), a CR filtration approach was designed to physically separate CR particles from CRMA. Fluorescence microscopy (FM), dynamic shear rheometer (DSR) tests, and gray relational analysis (GRA) were conducted on CRMA binders with different CR particle sizes and contents before and after filtration. The results indicate that the retained CR ratio ($R_{\mathit{cr}}$) increased with the increasing CR particle size and content, and coarser CR and higher CR contents generally increased G* and decreased δ, indicating enhanced high-temperature deformation resistance and recoverable deformation capacity of CRMA. After filtration, G* decreased markedly, whereas δ increased, and the quantified PE and IE results further indicate that the enhanced high-temperature rheological performance is dominated by PE, with IE providing an additional contribution, particularly at higher CR contents. Moreover, $R_{\mathit{cr}}$ correlated positively with G* and negatively with δ, and GRA suggested that CR content acts as the primary factor affecting high-temperature performance, while CR particle size serves as a secondary factor. Overall, this study provides practical guidance for optimizing CRMA design and supports improved asphalt service performance. Full article

Reducing cake fat while maintaining aeration, crumb softness, and consumer acceptance remains challenging because fat crystals contribute to interfacial stabilization and structure development. This study evaluated an interfacial processing strategy in which oil dispersion is refined by pre-emulsification to evaluate whether refining oil dispersion by pre-emulsification modulates the functional impact of lipase (via in situ formation of surface-active lipolysis products). A D-optimal design (16 formulations) quantified the effects of fat type (shortening vs. sunflower oil), fat level (100% vs. 50%), pre-emulsification (absent/present), and lipase dose (0, 50, 100 ppm; flour basis) on batter and baked-cake quality. Responses included moisture, color, volume/visual structure, texture and hedonic sensory evaluation for selected formulations. Lipase improved structure and texture, with the strongest benefits in reduced-fat samples, where hardness-related parameters decreased and volume/crumb refinement improved. Pre-emulsification modulated lipase performance in a formulation-dependent manner, indicating significant interactions. In sensory tests, the combined approach improved low-fat acceptance compared with the low-fat control. Overall, pre-emulsification-enabled lipase action offers a route to recover key quality attributes in low-fat cakes without conventional emulsifiers. Full article

Utilizing waste tire crumb rubber to modify asphalt enhances the damping and noise reduction performance of pavements. This study systematically evaluated the damping performance of crumb rubber–modified asphalt over a wide temperature range. A high-temperature damping index based on the loss factor and a low-temperature energy dissipation ratio derived from the Burgers model were proposed for quantitative characterization. The results show that damping performance is primarily controlled by temperature and crumb rubber content, while particle size plays a secondary role. Increasing crumb rubber content markedly improves damping performance. When the crumb rubber content exceeds 20%, the damping temperature stability, peak loss factor, and its retention tend to level off, whereas the low-temperature enhancement diminishes when the content exceeds 25%. Accordingly, the robust combinations are 80-mesh (≈180 μm) with 20% content for high-temperature conditions and 80-mesh with 25% content for low-temperature conditions. Multivariate nonlinear regression models achieved high predictive accuracy (R² = 0.927 and 0.985). Microscopic analyses indicate that crumb rubber increases constrained interfacial phases and system viscosity, and partial particle exposure at 20–25% further enhances interfacial friction and energy dissipation, consistent with the observed macroscopic damping behavior. These findings provide a theoretical basis for robust, noise-reducing pavements. Full article

Stone Mastic Asphalt (SMA) mixtures are widely used in high-capacity road pavements due to their durability and resistance to permanent deformation. However, although electric arc furnace (EAF) steel slag and recycled crumb rubber have been individually investigated as alternative materials in asphalt mixtures, evidence regarding their simultaneous incorporation in SMA mixtures under full-scale construction and real traffic conditions remains limited. Moreover, quantitative environmental assessments are often restricted to simplified or qualitative approaches, with limited reporting of carbon footprint results. This study investigates the combined use of electric arc furnace (EAF) steel slag aggregates and recycled crumb rubber in SMA mixtures, integrating laboratory evaluation with full-scale field application on a high-traffic motorway. Two SMA 11 mixtures were designed and assessed: one incorporating steel slag aggregates as a replacement for natural coarse aggregates, and another combining steel slag aggregates with recycled crumb rubber added through the dry process (0.8% by mixture mass). Laboratory testing included volumetric characterization, moisture sensitivity and rutting resistance, while field validation covered surface macrotexture, skid resistance, executed thickness and interlayer bonding. Both mixtures fully complied with the applicable technical specifications, achieving indirect tensile strength ratios (ITSR) above 90% and wheel-tracking slopes below 0.07 mm/10³ cycles. A simplified comparative life-cycle assessment (LCA), limited to modules A1–A3, showed a reduction in CO₂-equivalent emissions of approximately 2% for the mixture containing steel slag and up to 27% for the mixture combining steel slag and recycled crumb rubber, mainly due to the valorization of industrial by-products and end-of-life tyres. Overall, the results demonstrate the technical feasibility and potential environmental benefits of these SMA mixtures within the defined scope of laboratory verification, short-term field performance and screening LCA. The contribution of this study lies in providing applied evidence from a full-scale motorway intervention, complementing predominantly laboratory-based studies and offering a quantified environmental comparison under consistent methodological assumptions. Full article

Modern wheat breeding has focused on maximizing yields under high-input systems. Although ancient wheat varieties generally show lower yields and no clear nutritional superiority, they are increasingly valued in organic and local food systems for their resilience, cultural identity, and suitability for artisanal processing. This study evaluated the physicochemical, rheological, and technological properties of stone-milled flours and semolato from ancient common, durum, and Khorasan wheat to develop artisanal bread and pasta. Ancient cultivars showed relatively high protein content, ranging from 10.9% to 15.9% (on a dry matter basis). Gluten quality was generally weak, with gluten index values below 30% in most cultivars and alveograph W values below 60 × 10⁻⁴ J, mainly in durum wheats. Among common wheat cultivars, Autonomia B and Rano Solina showed the best bread-making suitability and were selected to produce bread prototypes via the application of pre-gelatinization. Optimized fermentation and pre-gelatinization significantly improved the crumb structure, softness, and sensory acceptance. Pasta from durum cv. Senatore Cappelli and Khorasan showed good cooking and sensorial quality, with Khorasan receiving a better score for overall acceptability. This study demonstrates that appropriate processing strategies can successfully unlock the technological and sensory potential of ancient wheat varieties, supporting their use in short value chains and enhancing product differentiation. Full article