Study on the Mechanism and Properties of Activated Crumb Rubber Modified Asphalt

2011 ◽  
Vol 239-242 ◽  
pp. 191-196 ◽  
Author(s):  
Dong Wei Cao ◽  
Hai Yan Zhang
Keyword(s):  
Crosslink Density ◽  
Three Dimensional ◽  
Crumb Rubber ◽  
Experimental Results ◽  
Cross Linking ◽  
Preparation Technology ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Dimensional Network ◽  
Swelling Capacity

In this study, the activated crumb rubbers (ACR) and these ACR modified asphalts were prepared. Effects of the preparation technology of modified asphalt and properties of activated crumb rubber on performance of modified asphalt have been investigated. The activated crumb rubber powder was characterized by the Rubber NMR Crosslink Density (RNCD). The mechanism of the activated crumb rubber modified asphalt (ACRMA) was analyzed by microcosmic measures and tests such as Fluorescence Microscope (FM) etc. The experimental results indicated that the chemical and physical activating methods can improve the swelling capacity of crumb rubber in the asphalt by destroying the three-dimensional network and decreasing the cross-linking density; ACRMA have better performance compared with the crumb rubber modified asphalt. Micrograph of the ACRMA demonstrated that the structure of ACRMA is more uniform and compact, and the performances of modified asphalt were improved significantly.

scholarly journals Optically transparent, high-toughness elastomer using a polyrotaxane cross-linker as a molecular pulley

2018 ◽  
Vol 4 (10) ◽  
pp. eaat7629 ◽  
Author(s):  
Hiroaki Gotoh ◽  
Chang Liu ◽  
Abu Bin Imran ◽  
Mitsuo Hara ◽  
Takahiro Seki ◽  
...  
Keyword(s):  
External Force ◽  
Matrix Material ◽  
Three Dimensional ◽  
Cross Linking ◽  
High Toughness ◽  
Dimensional Network ◽  
Cyclic Molecules ◽  
Optically Transparent ◽  
The Matrix ◽  
Special Challenge

An elastomer is a three-dimensional network with a cross-linked polymer chain that undergoes large deformation with a small external force and returns to its original state when the external force is removed. Because of this hyperelasticity, elastomers are regarded as one of the best candidates for the matrix material of soft robots. However, the comprehensive performance required of matrix materials is a special challenge because improvement of some matrix properties often causes the deterioration of others. For example, an improvement in toughness can be realized by adding a large amount of filler to an elastomer, but to the impairment of optical transparency. Therefore, to produce an elastomer exhibiting optimum properties suitable for the desired purpose, very elaborate, complicated materials are often devised. Here, we have succeeded in creating an optically transparent, easily fabricated elastomer with good extensibility and high toughness by using a polyrotaxane (PR) composed of cyclic molecules and a linear polymer as a cross-linking agent. In general, elastomers having conventional cross-linked structures are susceptible to breakage as a result of loss of extensibility at high cross-linking density. We found that the toughness of the transparent elastomer prepared using the PR cross-linking agent is enhanced along with its Young’s modulus as cross-linking density is increased.

The Preparation Technology and Performance Study of SBS and Rubber Powder Composite Modified Asphalt

2013 ◽  
Vol 361-363 ◽  
pp. 1617-1620 ◽  
Author(s):  
Li Liu ◽  
Zhao Hui Liu ◽  
Sheng Li
Keyword(s):  
Softening Point ◽  
Elastic Recovery ◽  
Powder Composite ◽  
Performance Study ◽  
Preparation Technology ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
And Performance

Taking SBS and rubber powder as modifier, adopting the dosage of 4%, 5%, and 6% of SBS while 2%, 4%, 6% of rubber powder to prepare composite modified asphalt, studied the preparation technology of composite modified asphalt, analyzed the trend of ductility, penetration, softening point and elastic recovery. The results show a certain SBS dosage, with the increase of the rubber powder, ductility decrease while softening point and elastic recovery increase, penetration decrease first and then rise. It can provide reference for the preparation technology and performance study of composite modified asphalt.

scholarly journals Swelling and Degradation Characteristics of Crumb Rubber Modified Asphalt during Processing

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Caiyun Xia ◽  
Mingyuan Chen ◽  
Jiuguang Geng ◽  
Xiaofeng Liao ◽  
Zhongda Chen
Keyword(s):  
Crumb Rubber ◽  
Continuous Phase ◽  
Expansion Ratio ◽  
Processing Technology ◽  
Processing Temperature ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Relationship Model ◽  
Long Time ◽  
Asphalt Performance

The existence of cross-linked structure in crumb rubber modified asphalt (CRMA) leads to the complexity of its system. According to the preparation test of CRMA under different processing technology, the influence of processing temperature and time on the properties and cross-linking structure of CRMA was analyzed. By analyzing the volume expansion rate of the rubber powder after swelling and the toluene insoluble content attenuation rate, the formation conditions of the macro-level cross-linked structure were determined, and the relationship model between the cross-linked structure and the rubber asphalt performance was established. The results show that the rubber particles can form a continuous phase structure after swelling. At this time, the expansion ratio of the swollen rubber powder was 1.76–2.14. Too high temperature (above 200°C) and too long time (above 60 min) caused serious degradation of rubber. The suitable processing technology was stirring at 180–190°C for 45–60 min.

Feasibility of Recycling Technology of Crumb Rubber Modified Asphalt

2014 ◽  
Vol 1073-1076 ◽  
pp. 960-964
Author(s):  
Jiu Guang Geng ◽  
Min Nan Zheng ◽  
Mei Qian Jin
Keyword(s):  
Softening Point ◽  
Crumb Rubber ◽  
Experimental Results ◽  
Technical Standards ◽  
Modified Asphalt ◽  
Technical Requirements ◽  
Asphalt Rubber ◽  
Recycling Technology ◽  
Recycling Agent ◽  
Design And Construction

The aged crumb rubber modified asphalt (abbreviated as CRMA) was recycled with two methods which were adding fresh CRMA binder and adding recycling agent to investigate the recycling feasibility of aged CRMA binder. The performance of recycled CRMA binder was evaluated systematically with a variety of indices, including penetration, softening point, ductility and viscosity. The results indicate that the performance of recycled CRMA binder has good correlation with the content of the fresh CRMA binder or recycling agent. The performance of recycled CRMA binder mixing with the fresh CRMA binder or recycling agent with the optimistic content is improved and can meet the technical requirements. According to the relevant technical standards in “Guidelines for design and construction of asphalt rubber and mixtures in Beijing”, the index of recycled CRMA binder can reach the standard when the content of fresh CRMA binder is 70% or content of recycling agent is 6%. The experimental results show that the recycling of the aged CRMA asphalt is feasible.

Utilizing Alginate to Improve Elasticity and Moisture Balance of Polyvinyl Alcohol/Chitosan Hydrogel Wound Dressing

2020 ◽  
Vol 988 ◽  
pp. 153-161
Author(s):  
Ria Barleany Dhena ◽  
Alwan Hafid ◽  
Milawati Aini ◽  
Bustomi Ahmad ◽  
Erizal
Keyword(s):  
Polyvinyl Alcohol ◽  
Wound Dressing ◽  
Three Dimensional ◽  
Chitosan Hydrogel ◽  
Equilibrium Degree ◽  
Dimensional Network ◽  
Alginate Concentration ◽  
Swelling Capacity ◽  
Moisture Balance ◽  
Moisture Vapour

Uncontrolled hemorrhage is the leading cause of death. The efficient hemostatic dressings are needed to promote coagulation and hold ongoing hemorrhage. Hydrogels are hydrophilic polymers with three-dimensional network structures with high swelling capacity to prevent accumulation of exudates. Hydrogels prepared from polyvinyl alcohol (PVA) grafted with chitosan have attracted considerable attentions due to their biocompatibility, high moisture balance property, and transparency. In this study, alginate was utilized to improve elasticity and thermal stability, also enhance hydrophilicity and increase swelling ability. The hydrogels composed of PVA (7.5 % w/v), chitosan (0.05 % w/v), and alginate (0.2, 0.4, and 0.6 % w/v) were synthesized by gamma irradiation technique at total dose of 15 kGy. The results showed that the increasing of alginate concentration in the total reactant mixture can improve elasticity, swelling capacity and the equilibrium degree of swelling (EDS), and decrease water vapour transmitted rate/moisture vapour transmitted rate (MVTR). The hydrogel wound dressing with 0.6 % of alginate concentration was the best product in this study with 79.49 % gel content, 608.65 % swelling ratio, 628.32 % EDS in 22 hours, elasticity 62.58 KPa, evaporation rate (MVTR) 105g/m2 h, degraded at temperature of 298.89oC, and the weight loss was reached 88.84 % (w/w).

Preparation Technology and Performance Analysis of Crumb Rubber and SBS Composite Modified Asphalt Binder

2010 ◽  
Vol 160-162 ◽  
pp. 1320-1324 ◽  
Author(s):  
Li Xiang ◽  
Zhi Gang Wang ◽  
Ying Du ◽  
Jian Cheng ◽  
Guo He Que
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Performance Comparison ◽  
Preparation Technology ◽  
Modified Asphalt ◽  
Comparison Results ◽  
Modified Asphalt Binder ◽  
Process Factors ◽  
And Performance ◽  
Separation Behavior

Based on the characteristics of SBS modified asphalt (SBSMA) and crumb rubber modified asphalt (CRMA), crumb rubber and SBS composites modified asphalt (CR/SBSCMA) technology is proposed combine the advantages of crumb rubber and SBS. The preparation technology and production process factors have been discussed in this work. Moreover, the performance comparison results of three modified asphalts confirms that CR/SBSCMA could achieve good high and low temperature performance with low content of SBS and crumb rubber. Furthermore, the separation behavior of CR/SBSCMA has been analyzed, the experimental results indicate that the separation behavior of CR/SBSCMA is caused by the sinkage of rubber particles as well as CRMA. However, the softening point difference of CR/SBSCMA after separation test is smaller greatly than CRMA due to the prevention of SBS particles.

scholarly journals Enhanced Storage Stability and Rheological Properties of Asphalt Modified by Activated Waste Rubber Powder

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2693
Author(s):  
Weihong Liu ◽  
Yishen Xu ◽  
Hongjun Wang ◽  
Benan Shu ◽  
Diego Maria Barbieri ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Large Scale ◽  
Storage Stability ◽  
Chemical Activation ◽  
Crumb Rubber ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Waste Rubber ◽  
Waste Rubber Powder ◽  
Physical And Chemical

Segregation of waste crumb rubber powder (WR) modified asphalt binders the large-scale application of WR in asphalt. The method of microwave activation combined with chemical activation (KMWR) was proposed to improve storage stability and rheological properties of WR modified asphalt in this work. Storage stability and rheological properties of virgin asphalt, MWR modified asphalt, and KMWR modified asphalt were comparatively studied by the standard segregation test, bending beam rheometer (BBR) test, and dynamic shear rheometer (DSR) test. The effect of composite activation on waste rubber powder particles was studied by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) tests. The main results showed that after the physical and chemical composite activation, the storage stability of waste rubber powder modified asphalt was significantly improved, WR modified asphalt had better crack resistance, better rutting resistance, and better fatigue performance. After physical and chemical activation, WR was desulfurized, and a large number of active groups was grafted on the WR particles.

scholarly journals Interpenetrating polymeric hydrogels as favorable materials for hygienic applications

2020 ◽  
Vol 10 (2) ◽  
pp. 5011-5020
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Synthetic Polymers ◽  
Poly Vinyl Alcohol ◽  
Ambient Conditions ◽  
Natural Polymers ◽  
Dimensional Network ◽  
Swelling Capacity ◽  
Polymeric Chains ◽  
Poly Ethylene

Polymers can crosslink to produce intermingled materials with three-dimensional network structure known as interpenetrating polymeric network (IPN). They comprise elastic crosslinked polymeric chains. The chains of the hydrogels are either physically or chemically entangled together. Interpenetrating hydrogels can be tailored to provide enhanced materials. They can be classified according to methods of their synthesis as simultaneous or sequential IPNs and the structure to be homo or semi IPNs. The preparation factors play a role in controlling the properties of the produced IPNs. Moreover, the ambient conditions such as pH, temperature as well as the ionic strength may affect the performance of these hydrogels. The swelling capacity is an important feature that allows the prepared hydrogel to perform the required application. Some disadvantages may arise such as the low mechanical properties that are suggested to be overcome. IPNs can be used in various applications that serve the human requirements like drug delivery, tissue engineering, medical and packaging applications. Hydrogels present biocompatibility and nontoxicity when used in biomedical applications. Interpenetrating hydrogels can be prepared from natural or synthetic polymers. Polysaccharides as natural polymers can be used to produce efficient interpenetrating hydrogels. Polyacrylates, poly(ethylene glycol) and poly(vinyl alcohol) are designated as promising synthetic polymers capable of forming interpenetrating hydrogels.

The fatigue behavior of polymeric sulfur-modified asphalt mixtures subjected to freeze-thaw conditioning

2019 ◽  
pp. 089270571988998 ◽  
Author(s):  
Amir Kavussi ◽  
Mehdi Azarnia ◽  
Pooyan Ayar ◽  
Makan Pedram
Keyword(s):  
Fatigue Life ◽  
Fatigue Behavior ◽  
Fatigue Cracking ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Experimental Results ◽  
Moisture Sensitivity ◽  
Modified Asphalt ◽  
Freeze Thaw ◽  
Brittle Behavior

Abundance, affordability, and also the usability of sulfur as a part of the binder are the main reasons for using this additive in asphalt mixtures. However, lack of proper adhesion and brittle behavior of sulfur-modified asphalt mixtures could make them susceptible to moisture damage and fatigue cracking. In this regard, anti-stripping agents and some polymers like crumb rubber may be used to overcome these types of distresses. This research aimed at investigating the effects of polymeric sulfur and crumb rubber on the moisture sensitivity and fatigue behavior of asphalt mixtures. To this end, asphalt mixtures were subjected to 1 and 3 freeze-thaw cycles. Then, an indirect tensile fatigue test was carried out. Moreover, the response surface method (RSM) was used to assess the interaction between various parameters in samples containing polymeric sulfur and crumb rubber. Results showed that with an increase in polymeric sulfur content, the fatigue life was reduced and the moisture sensitivity was increased. Additionally, the RSM was found to be effective in ranking parameters influencing the performance of asphalt mixtures. According to the experimental results, a crumb rubber-modified binder could improve the fatigue life of the polymeric sulfur-modified mixture up to 70%. Furthermore, experimental results and RSM analysis indicated that crumb rubber would be more effective in higher numbers of freeze-thaw cycles and raised temperatures, in which polymeric sulfur-modified asphalt mixtures are probably prone to moisture damages (i.e. the lack of adequate cohesion and adhesion).

Technical Standards of Rubber Asphalt and Crumb Rubber Modified Asphalt

2014 ◽  
Vol 900 ◽  
pp. 505-509
Author(s):  
Yu Mao ◽  
Fang Yuan Gong ◽  
Pei Wen Hao ◽  
Hai Nian Wang
Keyword(s):  
Production Process ◽  
Material Selection ◽  
Crumb Rubber ◽  
Scrap Tire ◽  
Technical Standards ◽  
Road Asphalt ◽  
Tire Rubber ◽  
Rubber Powder ◽  
Modified Asphalt ◽  
Scrap Tire Rubber

Rubber asphalt and crumb rubber modified asphalt are the internationally recognized best way to disposal of waste tires, harmless treatment and resource utilization. The applications of rubber asphalt and asphalt mixture with scrap tire rubber powder in the highway construction are in the ascendant and the relevant standards are the precondition of the application. In order to fit the needs of the development form, SINOPEC and Research Institute of Highway in the Ministry of Communications put forward their own standards, but with different definitions of waste crumb rubber modified road asphalt and obvious different technical standards, etc. So, in this paper according to the introduction and comparison of these two standards to further standardize the technical index of the scrap tire rubber powder, selection, production process, production process and technical index of rubber asphalt and crumb rubber modified asphalt and the material selection and the design process of mixture; the technical reference and support to the extensive application can be also got.

Sign in / Sign up

Export Citation Format

Share Document