Research on Modifier and Modified Process for Rubber-Particle Used in Rubberized Concrete for Road

2011 ◽  
Vol 243-249 ◽  
pp. 4125-4130 ◽  
Author(s):  
Shuai Tian ◽  
Tong Zhang ◽  
Ye Li

This paper studies the optimum proportion of rubber-particles in rubberized concrete for road, tests the impact of 12 modifiers and their modified processes in rubberized concrete and discusses the function mechanism of the modifiers in rubberized concrete. Research indicates: the optimum proportion of rubber-particles in rubberized concrete for road is low mix-proportion (volume ratio<5%); inorganic salt as modifier can markedly enhance the bonding strength between rubber-particles used in road and cement and improve the physical properties of rubberized concrete, among which CaCl2 produces the most effect; but organic solution, acidic or alkaline solutions are not fit to be used as modifiers in rubberized concrete for road.

2019 ◽  
Vol 9 (14) ◽  
pp. 2943
Author(s):  
Jiaqi Guo ◽  
Meng Huang ◽  
Shanxiu Huang ◽  
Sheng Wang

This study aimed to investigate the effects of the size and weight content of waste rubber particles on the relevant performances of rubberized concrete. First, the fine aggregates were partially replaced by rubber particles of different sizes to produce rubberized concrete. Secondly, the mechanical and thermal insulation properties of rubberized concrete were investigated. Finally, microstructural analyses of rubberized concrete including scanning electronic microscope (SEM) and energy distribution spectroscopy (EDS) were examined. Experimental results indicated that uniaxial compressive strength of rubberized concrete was reduced, while the peak strain was gradually increased and thermal insulation properties were improved with the increase of rubber content or decrease of rubber particle size. In addition, rubber particles affected the failure modes, endowing concrete with weak brittleness and strong cracking resistance. Additionally, it was observed that the interfacial adhesion between the matrix rubber and the aggregates was weak under SEM, which seemed to be a key factor that reduced the strength of rubberized concrete.


Author(s):  
Ling-Yun Feng ◽  
Ai-Jiu Chen ◽  
Han-Dong Liu

AbstractRubberized concrete is an environmentally friendly building material that mixes rubber particles from old automobile tires into normal concrete in place of fine aggregate. The addition of rubber particles can improve the abrasion resistance of normal concrete observably. It has a good application prospect in hydraulic engineering, especially in the concrete building parts with high abrasion resistance. However, there are few experimental studies on the abrasion resistance of rubberized concrete, and the influence law and mechanism of rubber particles on the abrasion resistance of concrete are not understood. In this paper, the abrasion resistance of rubberized concrete is studied using the underwater-steel-ball method. The results show that rubber particles increase the slump of concrete mixtures. The abrasion resistance of rubberized concrete increases significantly with increasing rubber particle content, whereas the compressive strength decreases linearly. For the same rubber particle size and content, the abrasion resistance of rubberized concrete positively correlates with compressive strength and larger rubber particles significantly improve the abrasion resistance. Rubber particle content is the factor that most strongly affects abrasion resistance of rubberized concrete, followed by the compressive strength. Rubber particle pretreatment methods of NaOH + KH570 can significantly improve the abrasion resistance of rubberized concrete.


2020 ◽  
Vol 12 (9) ◽  
pp. 1371-1380
Author(s):  
Yanhua Liu ◽  
Shiyu Tong ◽  
Qingxin Ren

In order to study the behavior of rubberized concrete-filled steel tubular (RuCFST) stub columns, an innovative composite member with steel tube and concrete filled with rubber particles was made. Twenty-four RuCFST stub columns were tested, in which six conventional CFST stub columns were prepared for comparison. The effects of changing rubber particle size (in the range of 1–2 mm and 2–5 mm) and rubber replacement ratio (0%, 10%, 20% replacement of sand) were made to discover the characteristics of the columns. The tested RuCFST stub columns displayed a local buckling similar to the conventional CFST stub columns. The tested results are compared with the predicted results of finite element analysis and the existing codes of CFST. Generally, the agreement between the predictions and results are reasonable.


2018 ◽  
Vol 9 (1) ◽  
pp. 79-84
Author(s):  
Vaishali V. Shahare ◽  
Rajni Grover ◽  
Suman Meena

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.


2020 ◽  
Vol 12 ◽  
Author(s):  
Sai Akilesh M ◽  
Ashish Wadhwani

: Infectious diseases have been prevalent since many decades and viral pathogens have caused global health crisis and economic meltdown on a devastating scale. High occurrence of newer viral infections in the recent years, in spite of the progress achieved in the field of pharmaceutical sciences defines the critical need for newer and more effective antiviral therapies and diagnostics. The incidence of multi-drug resistance and adverse effects due to the prolonged use of anti-viral therapy is also a major concern. Nanotechnology offers a cutting edge platform for the development of novel compounds and formulations for biomedical applications. The unique properties of nano-based materials can be attributed to the multi-fold increase in the surface to volume ratio at the nano-scale, tunable surface properties of charge and chemical moieties. Idealistic pharmaceutical properties such as increased bioavailability and retention times, lower toxicity profiles, sustained release formulations, lower dosage forms and most importantly, targeted drug delivery can be achieved through the approach of nanotechnology. The extensively researched nano-based materials are metal and polymeric nanoparticles, dendrimers and micelles, nano-drug delivery vesicles, liposomes and lipid based nanoparticles. In this review article, the impact of nanotechnology on the treatment of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV) viral infections during the last decade are outlined.


2021 ◽  
pp. 112070002110130
Author(s):  
Leigh-Anne Tu ◽  
Douglas S Weinberg ◽  
Raymond W Liu

Background: While the influences of acetabular dysplasia and overcoverage on hip arthritis have been studied, the impact of femoral neck-shaft angle on hip arthritis is much more poorly understood. The purpose of this study is to determine if a relationship exists between neck shaft angle and the development of osteoarthritis, a better understanding of which would be useful to surgeons planning osteotomies about the hip. Methods: 533 cadaveric femora and acetabulae (1066 total) from the Hamann-Todd Osteological Collection (Cleveland, OH) were acquired. We measured true neck shaft angle using an AP photograph with the femoral neck parallel to the table. Femoral head volume to acetabular volume ratio, representing femoral head coverage, as well as femoral version were utilised. Correlation between neck shaft angle, femoral version, femoral head coverage and osteoarthritis were evaluated with multiple regression analysis. Results: The mean age and standard deviation was 56 ± 10 years. There were 64 females (12%) and 469 males. There were 380 Caucasians (71%) and 153 African-Americans. Mean femoral version was 11° ± 12° and mean true neck shaft angle was 127.7° ± 5.9° There was a strong correlation between age and arthritis (standardised beta 0.488, p < 0.001). There was a significant correlation between increasing true neck shaft angle and decreasing hip arthritis (standardised beta -0.024, p = 0.038). In the femoral head overcoverage subset, increasing true neck shaft angle was still significantly associated with decreasing hip arthritis (standardised beta −0.088, p = 0.018), although this relationship was not significant with femoral head undercoverage subset. Conclusions: With sufficient acetabular coverage, a relative increase in femoral neck shaft angle within the physiologic range is associated with decreased hip osteoarthritis. Clinical relevance: An understanding of the relationship between femoral neck shaft angle and hip osteoarthritis could be useful for surgeons planning pelvic or proximal femur osteotomies in children.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1427
Author(s):  
Katarzyna Solarska-Ściuk ◽  
Kinga Adach ◽  
Sylwia Cyboran-Mikołajczyk ◽  
Dorota Bonarska-Kujawa ◽  
Agnieszka Rusak ◽  
...  

Silicon dioxide, in the form of nanoparticles, possesses unique physicochemical properties (size, shape, and a large surface to volume ratio). Therefore, it is one of the most promising materials used in biomedicine. In this paper, we compare the biological effects of both mesoporous silica nanoparticles extracted from Urtica dioica L. and pyrogenic material. Both SEM and TEM investigations confirmed the size range of tested nanoparticles was between 6 and 20 nanometers and their amorphous structure. The cytotoxic activity of the compounds and intracellular ROS were determined in relation to cells HMEC-1 and erythrocytes. The cytotoxic effects of SiO2 NPs were determined after exposure to different concentrations and three periods of incubation. The same effects for endothelial cells were tested under the same range of concentrations but after 2 and 24 h of exposure to erythrocytes. The cell viability was measured using spectrophotometric and fluorimetric assays, and the impact of the nanoparticles on the level of intracellular ROS. The obtained results indicated that bioSiO2 NPs, present higher toxicity than pyrogenic NPs and have a higher influence on ROS production. Mesoporous silica nanoparticles show good hemocompatibility but after a 24 h incubation of erythrocytes with silica, the increase in hemolysis process, the decrease in osmotic resistance of red blood cells, and shape of erythrocytes changed were observed.


2013 ◽  
Vol 844 ◽  
pp. 53-56
Author(s):  
Saravalee Saengthaveep ◽  
Sadhan C. Jana ◽  
Rathanawan Magaraphan

To produce a tough material for application demanding high impact resistance and low moisture absorption, melt blending of Nylon12 (Polyamide 12, PA12) and natural rubber (NR) was carried out in a brabender plasticorder at 210 °C with rotor speed of 70 rpm in the presence of polystyrene/maleated natural rubber (PS/MNR) blend as a compatibilizer. The effect of compatibilizer content (1, 3, 5, 7 and 10 phr) on phase morphology, thermal, and mechanical properties of [Nylon12/NR]/[PS/MNR] blends was investigated by using SEM, DSC, and Izod impact tester, respectively. The result revealed that PS/MNR blend improved the compatibility of Nylon12/NR blends efficiently due to the presence of amide linkage at the interfaces from the reaction between the reactive groups of MNR and the NH2 end groups of Nylon12 during mixing. A fine phase morphology (good dispersion and small dispersed phase size of NR domains in Nylon12 matrix) of [Nylon12/NR]/[PS/MNR] blends was observed at the optimum compatibilizer content of 7 phr, relating to the improvement of mechanical property. The impact energy of [Nylon12/NR]/[PS/MNR] blends was 503 J/m higher than that of neat Nylon12 (115 J/m) and Nylon12/NR binary blend (241 J/m) due to the toughening effect of rubber and proper morphology. The melting temperature of all blends did not change obviously from thermal analysis. However, the presence of rubber particle obstructed the crystallization of Nylon12 phase, leading to the decreasing of %crystallinity from 93% to around 70%.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1048 ◽  
Author(s):  
Maura Cesaria ◽  
Baldassare Di Bartolo

Miniaturization requests and progress in nanofabrication are prompting worldwide interest in nanophosphors as white-emission mercury-free lighting sources. By comparison with their bulk counterparts, nanophosphors exhibit reduced concentration quenching effects and a great potential to enhance luminescence efficiency and tunability. In this paper, the physics of the nanophoshors is overviewed with a focus on the impact of spatial confinement and surface-to-volume ratio on the luminescence issue, as well as rare earth-activated multicolor emission for white light (WL) output. In this respect, the prominently practiced strategies to achieve WL emission are single nanophosphors directly yielding WL by means of co-doping and superposition of the individual red, green, and blue emissions from different nanophosphors. Recently, a new class of efficient broadband WL emitting nanophosphors has been proposed, i.e., nominally un-doped rare earth free oxide (yttrium oxide, Y2O3) nanopowders and Cr transition metal-doped garnet nanocrystals. In regard to this unconventional WL emission, the main points are: it is strictly a nanoscale phenomenon, the presence of an emitting center may favor WL emission without being necessary for observing it, and, its inherent origin is still unknown. A comparison between such an unconventional WL emission and the existing literature is presented to point out its novelty and superior lighting performances.


2014 ◽  
Vol 8 (1) ◽  
Author(s):  
Kulyash Meiramkulova ◽  
Azamat Bayanov

Republic of Kazakhstan oil will last for 47.4 years, while gas production - 65.6 years. Given the Kashagan reserves, something else for a longer period, that is a very short periods of time with respect to the development of state and they can be extended only by the development of a technological breakthrough. Along with the question of the ever-growing needs of the population for energy resources, there is a question about the availability of annual waste generation as the impact of the rapid growth of the urban population, which is about 4% per year ("Population" encyclopedia of Astana, 2008). To cope with both problems simultaneously, the waste may be used as energy sources by fermentation technology. Among the urban wastes the organic waste is dominated, such as vegetables, fallen leaves, etc., that have the potential to produce biogas. The use of unsuitable materials as a natural catalyst of fermentation and the time spent on fermentation, are some of the existing barriers to the development of energy resources in urban areas. For this purpose a study was conducted to optimize the ratio of urban waste, animal waste and water in combination with the time of fermentation. The study used an experimental method with the random nature of the two-factor model. The first factor is the ratio of waste, manure, and the second quantity of water - during fermentation, which is fixed to each of 2, 4, 6, 8, 10, 12, 14, 16 and 18th day of the fermentation substrate. The study showed that the optimum proportion to obtain the maximum amount of biogas is a ratio of 500: 200: 300 waste, manure, and water, respectively. Furthermore, on the second day of fermentation the maximum amount of biogas produced.


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