The Environment-Friendly High-Elasticity Asphalt Mixture Using as Stress Absorbing Layer

2012 ◽  
Vol 490-495 ◽  
pp. 3753-3761
Author(s):  
Jun Yong Liu ◽  
Liu Jun Zhang ◽  
Bo Kou ◽  
Peng Shen
Keyword(s):  
Laboratory Test ◽  
Design Method ◽  
Asphalt Mixture ◽  
Element Model ◽  
New Materials ◽  
High Elasticity ◽  
New Material ◽  
Absorbing Layer ◽  
Materials Used ◽  
As Stress

The rubber- fly ash modified asphalt mixture formula was made by comprehensive laboratory test. The mixture graduation was determined with improved Superpave design method. The new material had good performance through laboratory test. The overlay of old concrete pavement was analyzed by establishing finite element model. The layer-layers could set stress absorbing layers or not; Stress absorbing layer had a absorption effect on stress in cracks and inhibiting effect on crack expanding. The results show that: the stress-absorbing layer of new materials can significantly reduce the stress concentration in cracks, effectively prevent the development of reflection crack and has excellent crack resistance. Meanwhile the adaptability of new materials used as stress absorbed layer is verified

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

Materials technology: Innovations and progress

Impact ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 52-53
Author(s):  
Lucy Sharp
Keyword(s):  
Material Properties ◽  
New Materials ◽  
Medical Problems ◽  
Technology Innovations ◽  
Societal Challenges ◽  
New Material ◽  
Innovative Materials ◽  
The Creation ◽  
Novel Applications

Materials technology is a constantly evolving discipline, with new materials leading to novel applications. For example, new material properties arise from combining different materials into composites. Researching materials can help solve societal challenges, with the creation of innovative materials resulting in breakthroughs in overcoming hurdles facing humankind, including energy challenges and medical problems. Innovative materials breathe new life into industries and spur on scientific and technological discovery.

scholarly journals Research on Improving the Durability of Bridge Pavement Using a High-Modulus Asphalt Mixture

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1449
Author(s):  
Wenfeng Wang ◽  
Shaochan Duan ◽  
Haoran Zhu
Keyword(s):  
Construction Industry ◽  
Mechanical Response ◽  
Design Method ◽  
Asphalt Mixture ◽  
Field Tests ◽  
Bottom Layer ◽  
High Modulus ◽  
Practical Applications ◽  
Depth Prediction ◽  
Pavement Structure

In order to improve the durability of the asphalt pavement on a cement concrete bridge, this study investigated the effect of the modulus of the asphalt mixture at the bottom layer on the mechanical response of bridge pavement, along with a type of emerging bridge pavement structure. In addition, the design method and pavement performance of a high-modulus asphalt mixture were investigated using laboratory and field tests, and the life expectancy of the deck pavement structure was predicted based on the rutting deformation. The results showed that the application of a high-modulus asphalt mixture as the bottom asphalt layer decreased the stress level of the pavement structure. The new high-modulus asphalt mixture displayed excellent comprehensive performance, i.e., the dynamic stability reached 9632 times/mm and the fatigue life reached 1.65 million cycles. Based on the rutting depth prediction, using high-modulus mixtures for the bridge pavement prolonged the service life from the original 5 years to 10 years, which significantly enhanced the durability of the pavement structure. These research results could be of potential interest for practical applications in the construction industry.

scholarly journals Environmentally Friendly, High-Performance Fire Retardant Made from Cellulose and Graphite

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2400
Author(s):  
Leandra P. Santos ◽  
Douglas S. da Silva ◽  
Thais H. Morari ◽  
Fernando Galembeck
Keyword(s):  
High Performance ◽  
Raw Materials ◽  
Fire Retardant ◽  
Visual Observation ◽  
Flame Resistance ◽  
New Developments ◽  
New Class ◽  
New Material ◽  
Accredited Laboratory ◽  
Materials Used

Many materials and additives perform well as fire retardants and suppressants, but there is an ever-growing list of unfulfilled demands requiring new developments. This work explores the outstanding dispersant and adhesive performances of cellulose to create a new effective fire-retardant: exfoliated and reassembled graphite (ERG). This is a new 2D polyfunctional material formed by drying aqueous dispersions of graphite and cellulose on wood, canvas, and other lignocellulosic materials, thus producing adherent layers that reduce the damage caused by a flame to the substrates. Visual observation, thermal images and surface temperature measurements reveal fast heat transfer away from the flamed spots, suppressing flare formation. Pinewood coated with ERG underwent standard flame resistance tests in an accredited laboratory, reaching the highest possible class for combustible substrates. The fire-retardant performance of ERG derives from its thermal stability in air and from its ability to transfer heat to the environment, by conduction and radiation. This new material may thus lead a new class of flame-retardant coatings based on a hitherto unexplored mechanism for fire retardation and showing several technical advantages: the precursor dispersions are water-based, the raw materials used are commodities, and the production process can be performed on commonly used equipment with minimal waste.

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

scholarly journals Chemical and Physical Properties of Limestone Powder as a Potential Microfiller of Polymer Composites

2017 ◽  
Vol 63 (2) ◽  
pp. 67-78 ◽  
Author(s):  
M. Kępniak ◽  
P. Woyciechowski ◽  
W. Franus
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Physical Properties ◽  
Polymer Composites ◽  
Asphalt Mixture ◽  
Limestone Powder ◽  
Coarse Aggregates ◽  
Mineral Powder ◽  
Materials Used ◽  
Scanning Electron

Abstract The preliminary stage of asphalt mixture production involves the drying and dedusting of coarse aggregates. The most common types of coarse aggregates used are limestone and basalt. In the process of drying and dedusting the dryer filter accumulates large quantities of waste in the form of mineral powder. This paper introduces an investigation into limestone powder waste as a potential microfiller of polymer composites. Physical characteristics such as the granulation the of powder collected from the filter - in terms of the season of its collection and the type of input materials used - were analysed. A scanning electron microscope (SEM) was used for the investigation described within this paper. The obtained results were compared against those of other materials which can be used as polymer composites microfillers.

Possible Causes in Breaking of Dental Implants Research

2017 ◽  
Vol 907 ◽  
pp. 104-118
Author(s):  
Maria Stoicănescu ◽  
Eliza Buzamet ◽  
Dragos Vladimir Budei ◽  
Valentin Craciun ◽  
Roxana Budei ◽  
...  
Keyword(s):  
Dental Implants ◽  
Dental Implant ◽  
Scientific Literature ◽  
Surface Characteristics ◽  
Raw Material ◽  
New Materials ◽  
Materials Used ◽  
Type Of Failure ◽  
First Time ◽  
Consequent Increase

Dental implants are becoming increasingly used in current dental practice. This increased demand has motivated manufacturers to develop varieties of product through design, but also looking for new materials used to improve surface characteristics in order to obtain a better osseointegration. But the increase in the use of implants goes to a consequent increase in the number of failures. These failures are caused either by treatment complications (peri-implantitis), by fatigue breakage under mechanical over-stress, by defective raw material, or due to errors during the insertion procedures. Although they are rare, these complications are serious in dentistry. Before to market a dental implant to clinical practitioners, the product is validated among other determinations in number of biocompatibility research. Raw material issues, details about its structure and properties are less published by the scientific literature, but all this are subject of a carefully analysis of the producers. Breaking of dental implants during surgical procedures, during the prosthetic procedures or during use (chewing, bruxism, accidents, etc.), is the second most common cause of loss of an implant after consecutive peri-implantitis rejection. Although the frequency of this type of failure for a dental implant is much smaller than those caused by the peri-implantitis, a detailed study of broken implants can explain possible causes. The use of scanning electron microscopy (SEM) in the study of the cleave areas explain the production mechanism of cleavages, starting from micro-fissures in the alloy used for the production of dental implants. These micro-fissures in weak areas of the implant (anti-rotational corners of the polygons, etc.) could generate a serious risk of cleavage first time when a higher force is applied.

Rutting Treatment Technology of Asphalt Pavement of Abrupt Slope Section in Heavy Load and High Temperature Zone

2011 ◽  
Vol 287-290 ◽  
pp. 858-861
Author(s):  
Hui Wang ◽  
Zhou Qing Zhao ◽  
Jian Zeng
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Polyester Fibre ◽  
Asphalt Mixture ◽  
Good Control ◽  
Treatment Technology ◽  
Heavy Load ◽  
Test Road ◽  
Overlay Design ◽  
New Material

Aiming at the characteristics of pavement rutting damage of test road under the condition of heavy load and abrupt slope, an overlay design scheme and a new overlay material with high performance was proposed. The new material is PG82 modified asphalt SMA-13 added polyester fibre which can significantly improve the high temperature performance of asphalt mixture under severe environment, and its strength and crack resistance are superior to normal SMA-13. Tracking survey of test road shows that the pavement performances keeps good and rutting is under good control. Therefore those measurements are successful and can be a reference to similar projects.

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