Study on Double-Frequency Composed Vibrating Compaction Method Based on Resonance and Antifriction Principle

2011 ◽  
Vol 402 ◽  
pp. 742-746 ◽  
Author(s):  
Yun Shi Yao ◽  
Zhong Xu Feng ◽  
Yan Wei Li ◽  
Xin Shi
Keyword(s):  
Surface Layer ◽  
Traditional Method ◽  
Asphalt Mixture ◽  
Variable Frequency ◽  
Compaction Process ◽  
Variable Amplitude ◽  
Double Frequency ◽  
Large Amplitude Oscillation ◽  
Compaction Method ◽  
Better Than

For improving compaction process, a method of double-frequency composed vibrating compaction was proposed, which based on resonance and antifriction principle. The method was different from the traditional variable-frequency and variable-amplitude compaction method, which has one frequency and associated amplitude. Double-frequency composed vibrating compaction method has two different frequencies and associated amplitudes simultaneously, thus enhanced resonance and antifriction of asphalt mixture, and large amplitude oscillation was prone to deep transmission of impact energy. The results showed that double-frequency composed vibrating compaction machine got higher degree of compaction than that of traditional machine with same tonnage, 2.6% higher in surface layer and 3.1% higher at the position 15 cm far from surface. Double-frequency composed vibrating compaction method was better than traditional method in concerned with the compactness in layers, and had obviously advantage of deep compaction.

Research on Designing Optimum Asphalt Aggregate Ratio of Asphalt Mixture by Mechanical Index Method

2012 ◽  
Vol 204-208 ◽  
pp. 1586-1592
Author(s):  
Hong Mei Li ◽  
Wen Fang Liu
Keyword(s):  
Shear Stress ◽  
Surface Layer ◽  
Internal Friction ◽  
Bond Strength ◽  
Asphalt Mixture ◽  
Friction Angle ◽  
Good Effect ◽  
Mechanical Index ◽  
Index Method ◽  
Better Than

The article designed optimum asphalt aggregate ratio of asphalt mixture by mechanical index method, the purpose of the mechanical index method is that the bond strength and internal friction angle of asphalt mixture can reach a best balance, the shear stress reaches the maximum, so the results have a good effect for preventing rut. The research indicated that the surface layer performance of asphalt mixture which designed by the mechanical index method is better than by the traditional Marshall method, so the mechanical index method is a simple and effective method.

A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt

2019 ◽  
Author(s):  
Teng Man
Keyword(s):  
Hybrid Model ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Particle Rearrangement ◽  
Compaction Behavior ◽  
Grain Size Distributions ◽  
Gyratory Compaction

The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.

Effects of a Combination of Stances and Points of Aim on Putting Accuracy

1988 ◽  
Vol 66 (1) ◽  
pp. 139-143 ◽  
Author(s):  
Erich Gott ◽  
Carl Mc Gown
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Traditional Method ◽  
Constant Error ◽  
Popular Opinion ◽  
Variable Error ◽  
Repeated Measures Analysis ◽  
Better Than

The purpose of this study was to determine the effects of two putting stances (conventional versus side-saddle) and two points of aim (ball versus hole) on putting accuracy. Subjects (12 men, 4 women) were taught to putt using four methods: (a) conventional stance, eyes on the ball; (b) conventional stance, eyes on the hole; (c) side-saddle stance, eyes on the ball; and (d) side-saddle stance, eyes on the hole. Each subject practiced each method for 2 wk., after which they were tested for purring accuracy by counting putts made, determining constant error, and by calculating variable error. Accuracy was assessed at 5 and 15 ft. A 2 by 2 repeated-measures analysis of variance showed that there was no single combination of stance and point of aim that was significantly better than another at either distance. This suggests that, contrary to popular opinion, the traditional method of putting is not the best method for putting; other methods are equally as good and could be used if individually desired.

Automatic Classification of ECG Using Multi-Classifiers with a New Fusion Method

2014 ◽  
Vol 687-691 ◽  
pp. 3917-3922
Author(s):  
Yi Chang Wang ◽  
Feng Qi Yan ◽  
Yu Fang
Keyword(s):  
Traditional Method ◽  
Heart Beat ◽  
Vector Model ◽  
Support Vector ◽  
Beat Classification ◽  
Computer Aided Analysis ◽  
Important Basis ◽  
Voting Method ◽  
Better Than

ECG signal contains abundant information of human heart activity. It is important basis of doctors’ diagnose. With the development of computer technology, computer aided analysis has been widely applied in the field of ECG analysis. Most of the traditional method is based on single classifier and too complex. Also, the accuracy is not high. This paper focuses on ECG heart beat classification, extracting different types of feature, training different classifiers by vector model and support vector machine (SVM), merging the result of multiple classifiers. In this paper, we used the advanced voting method (voting by weight) to fusion the result of different classifier, having compared it with the traditional voting method.It performed better than traditional method in term of accuracy

scholarly journals Comparison of Potential Contribution of Typical Pavement Materials to Heat Island Effect

2020 ◽  
Vol 12 (11) ◽  
pp. 4752 ◽  
Author(s):  
Hailu Yang ◽  
Kai Yang ◽  
Yinghao Miao ◽  
Linbing Wang ◽  
Chen Ye
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Potential Contribution ◽  
Heat Island ◽  
Cement Concrete ◽  
Porous Asphalt ◽  
Pavement Materials ◽  
Island Effect ◽  
Urban Heat ◽  
Better Than

Pavement materials have significant influence on the urban heat island effect (UHIE). This paper presents a study on the potential effects of pavement materials on UHIE in a natural environment. Three typical pavement materials, including cement concrete, dense asphalt concrete and porous asphalt mixture, were selected to evaluate their anti-UHIE properties by testing. In this paper, heat island potential (HIP) is proposed as a new index to analyze the influence of pavement materials on UHIE. It is shown that the temperature inside a pavement distinctly depends on the depth, and varies, but is usually higher than the air temperature. Solar radiation in the daytime significantly contributes to the temperature of pavement surface and the upper part. The correlation becomes weak at the middle and the bottom of pavements. Among the three materials tested in this study, the anti-UHIE performance of cement concrete is significantly higher than that of the other asphalt mixtures, while the porous asphalt mixture is slightly better than the dense asphalt concrete in anti-UHIE.

scholarly journals Determination of Construction Parameters of Porous Ultra-Thin Overlays Based on Laboratory Compaction Studies

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4496
Author(s):  
Jiahao Tian ◽  
Sang Luo ◽  
Ziming Liu ◽  
Xu Yang ◽  
Qing Lu
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Combination Method ◽  
Compaction Temperature ◽  
Pavement Maintenance ◽  
Energy Equivalence ◽  
New Type ◽  
Better Than

To address the severe distresses of asphalt pavement, a new type of pavement maintenance treatment, porous ultra-thin overlay (PUTO) with small particle size was proposed. The PUTO has a thickness of 1.5–2.5 cm and a large void ratio of 18–25%. As a newly asphalt mixture, the structure characteristics differ from poor traditional pavement. Therefore, it is necessary to investigate the fabrication schemes in laboratory and on-site, respectively. In this study, the optimal fabrication schemes, including compaction temperature and number of blows of PUTO were determined based on Cantabro test and volumetric parameters. Then, the corresponding relationship between laboratory and on-site compaction work was then established based on the energy equivalent principle. On this basis, the numbers of on-site rolling passes and the combination method were calculated. The results show that increased compaction temperature and number of blows reduce the height and enhance the compaction of the Marshall sample. With the same temperature and number of blows, the raveling resistance of coarse gradation, Pavement Asphalt Concrete-1 (PAC-1) is better than that of fine gradation, Pavement Asphalt Concrete-2 (PAC-2), and the increased asphalt viscosity significantly improves the raveling resistance of the asphalt mixture. To ensure the scattering resistance and volumetric characteristic, the initial compaction temperature of the PAC-1 and PAC-2 should not be lower than 150 °C and 165 °C, respectively. Then, the laboratory compaction work and on-site compaction work were calculated and converted based on the principle of energy equivalence. Consequently, the on-site compaction combination of rolling machines for four asphalt mixtures was determined. According to the volumetric parameters, the paving test section proved that the construction temperature and the on-site rolling combination determined by laboratory tests are reasonable, and ultra-thin overlay has good structural stability, drainage, and skid resistance.

Interpretation of Transverse Profiles to Determine the Source of Rutting within an Asphalt Pavement System

2005 ◽  
Vol 1905 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Claude Villiers ◽  
Reynaldo Roque ◽  
Bruce Dietrich
Keyword(s):  
Surface Layer ◽  
Literature Review ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Falling Weight Deflectometer ◽  
Relative Contribution ◽  
Transverse Profile ◽  
Falling Weight ◽  
Different Sources

The transverse profilograph has been recognized as one of the most accurate devices for the measurement of rut depth. However, interpretation of surface transverse profile measurements poses a major challenge in determining the contributions of the different layers to rutting. A literature review has shown that the actual rutting mechanism can be estimated from a surface transverse profile for determination of the relative contribution of the layers to rutting. Unfortunately, much of the research yielded no verification or data. In addition, some techniques presented cannot be used if the rut depth is not well pronounced. Other techniques may be costly and time-consuming. The present research developed an approach that integrates ( a) falling weight deflectometer and core data along with 3.6-m transverse profile measurements to assess the contributions of different pavement layers to rutting and ( b) identifies the presence (or absence) of instability within the asphalt surface layer. This approach can be used regardless of the magnitude of the rut depth. On the basis of the analysis conducted, absolute rut depth should not be used to interpret the performance of the asphalt mixture. In addition, continued instability may not result in an increase in rut depth because the rutted basin broadens as traffic wander compacts or moves the dilated portion of the mixture. The approach developed appears to provide a reasonable way to distinguish between different sources of rutting. The conclusions drawn from analysis of the approach agreed well with observations from the trench cuts taken from four sections.

scholarly journals Dynamic Water Effect on the High Temperature Stability of Asphalt Mixture

2012 ◽  
Vol 5 ◽  
pp. 352-357 ◽  
Author(s):  
Ming Hao Hou ◽  
Yi Qiu Tan ◽  
Bin Hu
Keyword(s):  
High Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Viscosity ◽  
Test Method ◽  
Water Effect ◽  
High Temperature Stability ◽  
Air Voids ◽  
Working Together ◽  
Better Than

This paper introduces dynamic water effect into the test, develops a laboratory test device for simulating the dynamic water effect on asphalt pavement, and puts forward a test method of dynamic water effect working together with load, water and temperature. Based on this method, the high temperature stability of seven kinds of asphalt mixtures with the factors of asphalt grade, gradation and air voids are studied. The research shows that the effect of dynamic water can take adverse effect for the high temperature stability of asphalt mixture. The effect degree is different under different factors. It is the most disadvantaged when the air voids of the mixture is near 10%, the skeleton structure gradation of mixture is better than the suspended structure at the most disadvantage air voids, and the mixture made of high viscosity asphalt is more affected when the temperature is higher.

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.

Influence of Double-Doped Admixtures on Asphalt Mixture Performance

2012 ◽  
Vol 557-559 ◽  
pp. 329-333
Author(s):  
Zhong Run Zheng ◽  
Chao Zhao ◽  
Yi Feng Zhao ◽  
Pei Song
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Rutting Resistance ◽  
Splitting Test ◽  
Improvement Effect ◽  
Low Temperature Cracking ◽  
Better Than

This paper introduces an asphalt mixture that mixed with different admixtures, rutting resistance agent and lignin fiber, at the same time. Rutting test and freeze-thaw splitting test are used to analyze rutting resistance on the high temperature and low temperature cracking of the asphalt mixture. The experiments with different mixes material composition are conducted to analysis various properties of the two admixtures on the mixture, especially the high temperature stability, low temperature crack resistance and the law of improvement effect. In addition, the experiments also determine the optimal asphalt content of different type of mixtures. The results showed that the single-doped KTL rutting resistance or lignin fibers have some improvement in water temperature performance of asphalt mixture, stability improvement of double-doped admixture asphalt mixture is better than the single-doped asphalt mixture, such as KTL rutting resistance agents and lignin fibers

Sign in / Sign up

Export Citation Format

Share Document