The Mechanical Characteristics of the under Layer of Pavement of Large-Stone Asphalt Mixes

2012 ◽  
Vol 598 ◽  
pp. 631-634 ◽  
Author(s):  
Hui Xia Li ◽  
Shen Jia Tong
Keyword(s):  
Asphalt Pavement ◽  
Temperature Stability ◽  
Effect Of Temperature ◽  
High Temperature Stability ◽  
Asphalt Mixes ◽  
Reflection Cracking ◽  
Large Stone ◽  
Base Course ◽  
Relationship Of ◽  
The Relationship

The Large-stone Asphalt Mixes (LSM)is adopted to solve the problems of the inadequate rutting resistance and poor durability to the asphalt pavement because of the good properties of high temperature stability and eliminating the reflection cracking. As under layer of asphalt pavement the Large-stone Asphalt Mixes is less researched than base course. The mechanical properties of every pavement layer can be analyzed under the effect of temperature and load coupling when the height of LSM (Large-Stone Asphalt Mixes) is different. Combined the properties with the demand of structure and the relationship of the layer and maximum nominal diameter, recommend the resonable height of the LSM.

Modeling and Numerical Simulation of the Effect of Temperature on the LCF Behaviour of a CuCrZr Alloy Specimen

2020 ◽  
Vol 50 ◽  
pp. 37-47
Author(s):  
M. Benhaddou ◽  
M. Ghammouri ◽  
Z. Hammouch ◽  
F. Latrache
Keyword(s):  
Test Piece ◽  
Low Cycle Fatigue ◽  
Effect Of Temperature ◽  
Cycle Fatigue ◽  
Alloy Specimen ◽  
Number Of Cycles ◽  
Increasing Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Cylindrical Test

The main originality of this work consists in investigating low cycle fatigue of cylindrical test piece with wings under imposed constraint and for the temperature 20°c, 200°c, 400°c. Based on a combination between the fatigue parameter of Jiang-Sehitoglu and the relationship of Coffin-Manson, a numerical model for the prediction of the number of cycles at break. It was found that the CuCrZr cylindrical test piece showed a reduction in fatigue life with increasing temperature.

scholarly journals The Mechanism of High-Strength Quenching-Partitioning-Tempering Martensitic Steel at Elevated Temperatures

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 94 ◽  
Author(s):  
Ke Zhang ◽  
Maoyuan Zhu ◽  
Bitong Lan ◽  
Ping Liu ◽  
Wei Li ◽  
...  
Keyword(s):  
Retained Austenite ◽  
Elevated Temperatures ◽  
Martensitic Steel ◽  
Lath Martensite ◽  
Temperature Stability ◽  
High Strength ◽  
High Temperature Stability ◽  
High Deformation ◽  
Heat Treated ◽  
The Relationship

High-strength medium-carbon martensitic steel was heat treated through a quenching-partitioning-tempering (Q-P-T) treatment. Both the mechanism for improved ductility and the high temperature stability of austenite were investigated. The Q-P-T martensitic steel showed good products of strength and elongation (PSE) at various deformation temperatures ranging within 25–350 °C. The optimum PSE value (>57,738 MPa%) was achieved at 200 °C. The microstructure of the Q-P-T steel is constituted of laths martensite with dislocations, retained austenite located within lath martensite and small niobium carbides (NbC), and/or transitional ε-carbides that precipitated in the lath martensite. The good ductility can be mainly attributed to the laminar-like austenite that remained within the lath-martensite. The austenite can effectively enhance ductility through the effect of dislocation absorption by the retained austenite and through transformation-induced plasticity. The relationship between the microstructures and mechanical properties was investigated at high deformation temperatures.

The Performance Analysis of Semi-Flexible Pavement by the Volume Parameter of Matrix Asphalt Mixture

2010 ◽  
Vol 168-170 ◽  
pp. 351-356 ◽  
Author(s):  
Qing Jun Ding ◽  
Zheng Sun ◽  
Fan Shen ◽  
Shao Long Huang
Keyword(s):  
Pore Structure ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Flexible Pavement ◽  
High Temperature Stability ◽  
Important Target ◽  
Air Void ◽  
Better Than ◽  
Pavement Material

The volume parameter of matrix asphalt mixture is an important target in the design of the semi-flexible pavement. The research used volume-standar to design four kinds of matrix asphalt mixture, fulfilled mechanics performances and performances of semi-flexible pavement material with different aging, compared with common asphalt mixture and researched the effect by air void and pore structure. It proves that the compacted intensity, high-temperature stability and low temperature bend of the semi-flexible pavement material is better than common asphalt pavement material, the performances of matrix asphalt mixture with high air void is better. As for matrix asphalt mixture with same air void but different pore structure, the performances of homogenous grade design is prior to consecutive grade disign.

Natural Mineral Fiber Improved Asphalt Mixture Performance

2014 ◽  
Vol 638-640 ◽  
pp. 1166-1170 ◽  
Author(s):  
Meng Hui Hao ◽  
Pei Wen Hao
Keyword(s):  
Low Temperature ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Temperature Stability ◽  
Pavement Performance ◽  
High Temperature Stability ◽  
Natural Mineral ◽  
Mineral Fiber ◽  
Modified Asphalt

Natural mineral fiber with good performances of mechanical properties and environmentally friendly, pollution-free especially have gradually aroused extensive concern. In order to improve the quality of asphalt pavement, explore the applicability of nature basalt fiber in enhanced asphalt mixture performance, this paper investigates two typical asphalt mixtures and contrastive studies pavement performance of asphalt mixture by high temperature stability, water stability, low temperature anti-cracking and fatigue performance between basalt fiber modified asphalt mixture and base asphalt mixture, and then study the basic principle of fiber reinforcing asphalt mixture. The research show that basalt fiber modified asphalt mixture has a better pavement performance than base asphalt mixture, its dynamic stability is 1.6 times than base asphalt mixture, low temperature anti-cracking performance increased by more 25% and fatigue life is more 2 times than base asphalt mixture. And the basalt fiber can be used in the road engineering as an additive material that enhances the comprehensive performance of asphalt pavement.

Design of SAW Specific Gas Sensor with High Sensitivity

2013 ◽  
Vol 303-306 ◽  
pp. 137-142
Author(s):  
Jin Yi Ma ◽  
Jing Yang ◽  
Bo Du ◽  
Lu Wang ◽  
Hong Min Jiang ◽  
...  
Keyword(s):  
High Temperature ◽  
Acoustic Wave ◽  
Specific Surface ◽  
Surface Area ◽  
Gas Sensor ◽  
Temperature Stability ◽  
High Sensitivity ◽  
Response Speed ◽  
High Temperature Stability ◽  
The Relationship

To improve the temperature stability, response speed and sensitivity of surface acoustic wave (SAW) gas sensor, the relationship between the sensing region of the resonator for SAW gas sensor and the sensitivity of sensor is studied, a specific resonator with big space topology structure is proposed. A SAW resonator with high temperature stability is investigated from the viewpoint of piezoelectric material, cut type and fabrication process. A nano-wire bundle based SAW gas sensor with big specific-surface-area is proposed.

Analysis of Concrete Bridge Asphalt Pavement’s High Temperature Stability

2012 ◽  
Vol 190-191 ◽  
pp. 419-422
Author(s):  
Hong Jiang ◽  
Jian Bo Yuan ◽  
Hua Yang
Keyword(s):  
High Temperature ◽  
Asphalt Pavement ◽  
Temperature Stability ◽  
Heating System ◽  
Engineering Practice ◽  
Concrete Bridge ◽  
High Temperature Stability ◽  
Important Indicator ◽  
Strong Basis ◽  
Thin Structure

The asphalt pavement of cement concrete bridge belongs to thin structure, its high temperature stability is an important indicator. Using self-made heating system, through test on full scale linear track, conduct on-site rutting survey, and supplemented by the identification of drill core samples and laboratory test of pavement’s rutting, research on asphalt pavement's high temperature stability on the bridge. The research results not only provide a strong basis to the concrete bridge asphalt pavement mix design, but also provide some reference to similar engineering practice.

scholarly journals Isolate some external parasites in some types of family Columbidae in the city of Baghdad

2012 ◽  
Vol 36 (0A) ◽  
pp. 157-164
Author(s):  
Suha Tariq Abdul-Karim
Keyword(s):  
First Record ◽  
Infestation Rate ◽  
Effect Of Temperature ◽  
Parasitic Infections ◽  
Soft Tick ◽  
Infection Rates ◽  
Total Rate ◽  
Relationship Of ◽  
The Relationship ◽  
The City

The aim of the study is to isolation and diagnose types of external parasites anddiagnosis in some family members Columbidae and seasonal distribution of theseparasites and the effect of temperature and humidity on the different infection rates are alsoexamining the relationship of sex and incidence of external parasitesStudy was conducted to detect parasitic infections in some types of foreign familyerythematosus where The results revealed that infestation of pigeons with one type of fliesPseudolynchia canariensis with total infestation rate was 3.33%, the highest infestation ratewas in March (13.04%) and the lowest infestation rate was in December (3.12%), this recordis consider a first record in Baghdad.The results revealed that the pigeons were infested with two Lice species, Columbicolacolumbae and Campanulotes bidentatus caompare in a rate 44.66%, 1.66% respectively withtotal rate 46.33%, the highest infestation rate was 68.57% in December and the lowest rate16.66% in August lowest was in August 15.38%, without any significant differencesrecorded.Diagnoses of one type of soft tick Argas persicus that taken from pigeon nests whichchecked – up with total rate was 35.71% (infestation with nymphs and adults) and the peakinfestation recorded in May 100% and the lowest was in March and July at a rate of 33.33%.The total rate for infestation of pigeon with larvae of tick was 2.33% and the highestinfestation was 8.33% in May and the lowest rate 2.43% in April.

Application of Large-Stone Asphalt Mixes in the Base Course Maintenance of Expressway

2010 ◽  
Vol 168-170 ◽  
pp. 1189-1192
Author(s):  
Hui Min Hu ◽  
Yong Yao Tong ◽  
Wang Li Zhang
Keyword(s):  
Maximum Shear Stress ◽  
Good Effect ◽  
Rigid Base ◽  
Asphalt Mixes ◽  
Porous Asphalt ◽  
Large Stone ◽  
Base Course ◽  
Longitudinal Cracks ◽  
Structural Layer

Large stone porous asphalt mixes have well drainage ability, as well as higher modulus and durability when used as base course. Large stone porous asphalt mixes have good effect on repairing the semi-rigid base course which have longitudinal cracks. It not only can delay the reflection of cracks, but also plays the role of excluding water in structural layer owing to relatively large porosity. Deflection value of upper base's top surface decreases and deflection difference between left and right wheel track reduces after paving large-stone asphalt mixes upper base. When there are longitudinal cracks in lower base course, top surface tensile stress of upper base(large-stone asphalt mixes flexible upper base course)has significantly reduced compared with semi-rigid base course upper base. And maximum shear stress declined slightly. It can play a very well crack resistance effect when using large-stone asphalt mixes to repair broken cement stability upper base.

scholarly journals Properties of a Steel Slag–Permeable Asphalt Mixture and the Reaction of the Steel Slag–Asphalt Interface

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3603 ◽  
Author(s):  
Wenhuan Liu ◽  
Hui Li ◽  
Huimei Zhu ◽  
Pinjing Xu
Keyword(s):  
Mineral Composition ◽  
Asphalt Pavement ◽  
Steel Slag ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
High Temperature Stability ◽  
X Ray ◽  
Marshall Stability

Steel slag is an industrial solid waste with the largest output in the world. It has the characteristics of wear resistance, good particle shape, large porosity, etc. At the same time, it has good adhesion characteristics with asphalt. If steel slag is used in asphalt pavement, it not only solves the problem of insufficient quality aggregates in asphalt concrete, but can also give full play to the high hardness and high wear resistance of steel slag to improve the performance of asphalt pavement. In this study, a steel slag aggregate was mixed with road petroleum asphalt to prepare a permeable steel slag–asphalt mixture, which was then compared with the permeable limestone–asphalt mixture. According to the Technical Regulations for Permeable Asphalt Pavement (CJJT 190-2012), the permeability, water stability, and Marshall stability of the prepared asphalt mixtures were tested and analyzed. In addition, the high-temperature stability and expansibility were analyzed according to the Experimental Regulations for Highway Engineering Asphalt and Asphalt Mixture (JTG E20-2011). The chemical composition of the steel slag was tested and analyzed by X-ray fluorescence spectrometer (XRF). The mineral composition of the steel slag was tested and analyzed by X-ray diffractometer (XRD). The asphalt was analyzed by Fourier transform infrared spectroscopy (FTIR). The results show that the steel slag asphalt permeable mixture had good permeability, water stability, and Marshall stability, as well as good high-temperature stability and a low expansion rate. The main mineral composition was ferroferric oxide, the RO phase (RO phase is a broad solid solution formed by melting FeO, MgO, and other divalent metal oxides such as MnO), dicalcium silicate, and tricalcium silicate. In the main chemical composition of steel slag, there was no chemical reaction between aluminum oxide, calcium oxide, silicon dioxide, and asphalt, while ferric oxide chemically reacted with asphalt and formed new organosilicon compounds. The main mineral composition of the steel slag (i.e., triiron tetroxide, dicalcium silicate, and tricalcium silicate) reacted chemically with the asphalt and produced new substances. There was no chemical reaction between the RO phase and asphalt.

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