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This study aims to research the implications of rubber powder utilisation, from tires recycling, in the deformability and strength properties of CPB. In the end, it will be concluded that mine paste backfill with recycled rubber materials contributes to the decrease of waste tire pollution and improve some mechanical properties of the filling body. For that purpose, tests were carried out to determine the uniaxial compressive strength, the elastic energy of deformation, Young's modulus, and Poisson's ratio in specimens made up of mine tailings, Portland cement, wastewater, rubber powder, and plasticisers. The analysis of experimental data determines that recycled rubber makes fresh slurry have better performance in flow characteristics. In the hardened state, recycled rubber reduces the uniaxial compressive strength of the specimens and Poisson's ratio, but other features like deformability increase (Young's modulus decrease) that enhance the ability to absorb elastic strain energy of the filling body. As a result, the study indicates that recycled rubber is applicable to rockburst prevention. The findings of this study provide both invaluable information and industrial applications for the efficient management of solid waste, based on sustainable development and circular economy. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the potential of Zn-solubilizing Pseudomonas strains to release Zn from tire waste powder (TWP) in a liquid medium and soil. A pot experiment was also conducted to investigate the effects of TWP (as a Zn source) at four rates of 0, 9, 18 and 27 g TWP kg−1 soil and Pseudomonas strains (Ctrl: without bacterial inoculation, or inoculated with B1: A5, B2: K5, B3: A2, B4: A11 or B5: D12 strain) on growth and Zn nutrition of maize. Fourteen bacterial strains were grown in liquid Pikovskayas (PVK) medium supplemented with TWP, and ten superior Pseudomonas strains with high Zn solubilization activities were selected for the subsequent Zn kinetics study. In the TWP-treated soil, the concentrations of DTPA-extractable Zn were significantly higher in inoculated treatments than those in the control treatment in all incubation times. Individual application of Pseudomonas strains or TWP treatments significantly increased the shoot biomass of maize plants. Furthermore, the combined application of Pseudomonas strains and TWP led to higher shoot Zn concentration of plants as compared to the individual applications. The highest shoot Zn concentration was observed with the use of 18 g TWP kg−1 soil in treatment inoculated with B4 strain, which was 16.5-fold higher than that in the control. These findings indicate that co-application of effective Pseudomonas strains with TWP in soils can lead to higher Zn bioavailability for plants, i.e. indicating the potential of TWP as a slow-release Zn fertilizer for crops. [ABSTRACT FROM AUTHOR]

According to the evidence of numerous advantages of earthen buildings, there is an increasing interest to study adobe elements for sustainable development. This paper presents experimental investigation alongside numerical simulation of several adobe elements under compression, direct tension, three-point bending and indirect shear tests to have a better understanding of their basic mechanical properties. Two different mix-design of clay adobes including plain and short tire fibers reinforced adobes with unique soil type, water content and compacting level are provided. The tire fibers are the waste production of tire factories which are hazardous to the green environment. Numerical simulations are conducted in ABAQUS software for further analysis. In this direction, the material constitutive model and the damage indices are defined based on the experimental stress-strain relations which are achieved during this study and the model of concrete damage plasticity was considered in the software. Furthermore, the experimental observations for direct tensile and indirect shear tests were documented by means of a Digital Image Correlation (DIC) technique from a 2-D DIC system. The effectiveness of the added short fibers on the mechanical properties of the reinforced adobe were thoroughly discussed. [ABSTRACT FROM AUTHOR]

Water contamination by pathogens and diseases induced by these pathogens is a major water quality issue all over the world. Poor public health has been linked to tap water polluted with DNA harboring antibiotic resistance genes sequence. According to HSAB concept, surface modification of rubber seed shell waste with alumina (AIRSS) as novel agro-waste adsorbent creates more active surface constituents for DNA adsorption. The proximate, ultimate and EDAX analysis provides the percentage levels of ash concentration, volatile, moisture and fixed carbon content, elemental composition present in the adsorbent. The structural features of AIRSS were determined using FT-IR, SEM and XRD. In order to improve reaction conditions, the effect of pH, temperature, adsorbent amount, and reaction time is also examined. The highest percent of DNA removal (92.5%) was achieved at the optimum conditions: 2 g/L at pH 4, contact time 120 minutes as compared to the conventional methods. The DNA adsorbs onto the surface of AIRSS through physical (vander Waals force) and chemical interactions, as demonstrated by kinetics and spectroscopic analyses. Changes in enthalpy (H), free energy (G), and entropy (S) indicate that adsorption is a spontaneous and exothermic process, according to thermodynamic parameters. The results of the experiments showed that the prepared AIRSP adsorbent could be used to remove DNA from water. The efficacy of AIRSS for the removal of DNA has decreased after nine months of storage and use. Low pH and the presence of AIRSS improved DNA-AIRSS adsorption, according to our findings. [ABSTRACT FROM AUTHOR]

Waste tire rubber has been incorporated into asphalt modification for decades due to its various benefits. There are two main mechanisms during bitumen–rubber interaction: rubber swelling and chemical degradation. This study surveys these two processes from the viewpoint of polymer science. The kinetics of rubber dissolution and thermodynamics of rubber swelling are discussed to provide a fundamental understanding of the interaction process and to demonstrate how optimisation of material selection and processing procedures can lead to the desired binder properties. Factors including the interaction conditions and raw material characteristics are analysed based on the previous theories and compared with experimental results. [ABSTRACT FROM AUTHOR]

In this article, the flexural fatigue tests of self-compacting rubberized concrete (SCRC) with different waste tire rubber contents were done to study the fatigue mechanical behavior. The result shows that the monotonic curve can well describe the fatigue failure strain. What's more, both the secondary strain rate per cycle and secondary stiffness rate per cycle can describe the flexural fatigue life of SCRC, and relationships are independent of the rubber content. Finally, the fatigue damage evolution model was proposed based on Weibull function, and it can be used to predict the fatigue damage evolution of SCRC accurately. [ABSTRACT FROM AUTHOR]

The use of granulated recycled rubber as a lightweight material in civil engineering applications has been widely growing over the past 20 years. Processed waste tires mixed with soils have been introduced as lightweight fills for slopes, retaining walls, and embankments. It has also been considered as a damping material under foundations in seismic zones. Understanding the properties of sand-rubber mixtures is essential to evaluate its performance in geotechnical applications. Isotopically consolidated drained (CD) triaxial tests were conducted to investigate the effect of rubber size, content and saturation condition on the mechanical properties of sand-rubber mixtures. Moreover, the compressibility of the sand-rubber mixtures under sustained loading was investigated through one dimensional consolidation tests. The unit weight, shear strength and stiffness of sand-rubber mixtures decreased whereas deformability increased at increased rubber content. A non-linear stress-strain response was observed, that changed from brittle to ductile behaviour at increased rubber content. Sand-rubber mixtures, under one dimensional loading, exhibited significant settlement that increased as rubber content increased. [ABSTRACT FROM AUTHOR]

From this study it was evident that outer peristaltic parts of waste tire granules gave the highest removal. Film and pore diffusions are the major factors controlling rates of sorption from solution by porous adsorbents. For sorption of 2,4‐D on waste tire rubber granules, the sorption rate coefficient of second‐order kinetic equation was utilized indirectly to determine the rate‐limiting step. The diffusion coefficient lies in the scale of 10 -8 cm 2 /s, and the pore diffusion coefficient is in the range of 10 -9 –10 -10 cm 2 /s. So both film and pore diffusion are rate limiting. Considering external mass transfer from fluid to particle, using the effect of initial concentration, and using the effect of adsorbent size, no conclusion was reached regarding rate‐controlling steps. It is apparent from the study that external mass transfer (film diffusion) as well as intra‐particle diffusion (pore diffusion) play significant roles in the sorption process for 2,4‐D removal from water onto rubber granules. [ABSTRACT FROM AUTHOR]