Research on Designing Optimum Asphalt Aggregate Ratio of Asphalt Mixture by Direct Shear Method

2014 ◽  
Vol 505-506 ◽  
pp. 215-218
Author(s):  
Hong Mei Li ◽  
Wen Fang Liu
Keyword(s):  
Permanent Deformation ◽  
Maximum Shear Stress ◽  
Asphalt Mixture ◽  
Confining Pressure ◽  
Asphalt Mixtures ◽  
Test Machine ◽  
Direct Shear ◽  
The Road ◽  
Good Ability ◽  
Shear Performance

The author has done the shear experiment of asphalt mixtures at different asphalt aggregate ratio and different confining pressure using the direct shear test machine, then determined the optimum asphalt aggregate ratio according to the maximum shear stress. The asphalt mixture under optimum asphalt aggregate ratio has better shear performance by this method, and this method can better simulate the road surface actual stressful condition, the asphalt mixture has a good ability of anti-permanent deformation and fatigue.

A Review of the Utilisation of Recycled Waste Material as an Alternative Modifier in Asphalt Mixtures

2020 ◽  
Vol 6 ◽  
pp. 42-60
Author(s):  
Abdalrhman Abrahim Milad ◽  
Ahmed Suliman B. Ali ◽  
Nur Izzi Md Yusoff
Keyword(s):  
Mechanical Performance ◽  
Permanent Deformation ◽  
Steel Slag ◽  
Asphalt Mixture ◽  
Construction Materials ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Waste Material ◽  
Waste Materials ◽  
The Road

The possibility of using waste materials in road construction is of great interest as their utilisation may contribute to reducing the problems of hazard and pollution and conserve natural resources. Thus, there is an urgent need to find a sustainable method for using waste materials as a substitute in the standard asphalt binders. There are several concerns about the physical and chemical properties and mechanical performance of asphalt pavements incorporated with waste material in the effort to reduce permanent deformation of the road surface. This review article presents a brief discussion of the asphalt mixtures modified with waste material, and the recycled materials used as a modifier in the asphalt mixture. The present paper summarises the use of crumb rubber, crushed concrete, steel slag, glass fibre and plastic waste in asphalt mixtures. The use of waste materials as a modifier in asphalt mixture resulted in improved asphalt pavement performance. Results advocate that rubberised asphalt mixture with desired properties can be designed as an additive with a friendly environmental approach in construction materials. The researches that adopted the influence of usage, recycle waste material to improve the performance of the asphalt of the road are still limited compared to other construction fields. Doi: 10.28991/cej-2020-SP(EMCE)-05 Full Text: PDF

scholarly journals Performance Evaluation of WMA Containing Re-Refined Acidic Sludge and Amorphous Poly Alpha Olefin (APAO)

2021 ◽  
Vol 13 (6) ◽  
pp. 3315
Author(s):  
Mansour Fakhri ◽  
Danial Arzjani ◽  
Pooyan Ayar ◽  
Maede Mottaghi ◽  
Nima Arzjani
Keyword(s):  
Resilient Modulus ◽  
Permanent Deformation ◽  
Road Construction ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Modified Bitumen ◽  
Alternative Source ◽  
The Road ◽  
Marshall Test ◽  
Alpha Olefin

The use of waste materials has been increasingly conceived as a sustainable alternative to conventional materials in the road construction industry, as concerns have arisen from the uncontrolled exploitation of natural resources in recent years. Re-refined acidic sludge (RAS) obtained from a waste material—acidic sludge—is an alternative source for bitumen. This study’s primary purpose is to evaluate the resistance of warm mix asphalt (WMA) mixtures containing RAS and a polymeric additive against moisture damage and rutting. The modified bitumen studied in this research is a mixture of virgin bitumen 60/70, RAS (10, 20, and 30%), and amorphous poly alpha olefin (APAO) polymer. To this end, Marshall test, moisture susceptibility tests (i.e., tensile strength ratio (TSR), residual Marshall, and Texas boiling water), resilient modulus, and rutting assessment tests (i.e., dynamic creep, Marshall quotient, and Kim) were carried out. The results showed superior values for modified mixtures compared to the control mix considering the Marshall test. Moreover, the probability of a reduction in mixes’ moisture damage was proved by moisture sensitivity tests. The results showed that modified mixtures could improve asphalt mixtures’ permanent deformation resistance and its resilience modulus. Asphalt mixtures containing 20% RAS (substitute for bitumen) showed a better performance in all the experiments among the samples tested.

scholarly journals Functional and environmental performance of plant-produced crumb rubber asphalt mixtures using the dry process

2021 ◽  
Vol 54 (5) ◽  
Author(s):  
M. Bueno ◽  
R. Haag ◽  
N. Heeb ◽  
P. Mikhailenko ◽  
L. Boesiger ◽  
...  
Keyword(s):  
Environmental Performance ◽  
High Performance ◽  
Large Scale ◽  
Fatigue Behavior ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Gaseous Emissions ◽  
Dry Process

AbstractIncorporating crumb rubber (CR) using the dry process, directly in the asphalt mixture rather than into the bituminous binder requires no plant retrofitting, and therefore is the most practical industrial method for CR incorporation into asphalt mixtures. Nevertheless, very few large scale studies have been conducted. This work uses a holistic approach and reports on the functional and environmental performance of asphalt mixtures with different concentrations of CR fabricated employing the dry process in asphalt plants. Gaseous emissions were monitored during the production and laboratory leaching tests simulating the release of pollutants during rain, was conducted to evaluate the toxicology of both the CR material alone and the modified asphalt mixtures. In addition, laboratory compacted samples were tested to assess their fatigue behavior. Furthermore, noise relevant surface properties of large roller compacted slabs were evaluated before and after being subjected to a load simulator (MMLS3) to evaluate their resistance to permanent deformation. The results confirm that comparable performance can be achieved with the incorporation of CR using the dry process for high performance surfaces such as semi-dense asphalt, which usually require the use of polymer modified binders. Environmental performance improvement can be achieved by a washing step of the CR material that could remove polar CR additives which have commonly been used as vulcanization accelerator during rubber production.

scholarly journals Viscoelastic Parameters of Asphalt Mixtures Identified in Static and Dynamic Tests

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2084 ◽  
Author(s):  
Piotr Mackiewicz ◽  
Antoni Szydło
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Dynamic Test ◽  
Asphalt Mixtures ◽  
Rheological Parameters ◽  
Dynamic Tests ◽  
Static Test ◽  
Viscoelastic Parameters ◽  
Static Creep ◽  
Asphalt Content

We present two methods used in the identification of viscoelastic parameters of asphalt mixtures used in pavements. The static creep test and the dynamic test, with a frequency of 10 Hz, were carried out based on the four-point bending beam (4BP). In the method identifying viscoelastic parameters for the Brugers’ model, we included the course of a creeping curve (for static creep) and fatigue hysteresis (for dynamic test). It was shown that these parameters depend significantly on the load time, method used, and temperature and asphalt content. A similar variation of parameters depending on temperature was found for the two tests, but different absolute values were obtained. Additionally, the share of viscous deformations in relation to total deformations is presented, on the basis of back calculations and finite element methods. We obtained a significant contribution of viscous deformations (about 93% for the static test and 25% for the dynamic test) for the temperature 25 °C. The received rheological parameters from both methods appeared to be sensitive to a change in asphalt content, which means that these methods can be used to design an optimal asphalt mixture composition—e.g., due to the permanent deformation of pavement. We also found that the parameters should be determined using the creep curve for the static analyses with persistent load, whereas in the case of the dynamic studies, the hysteresis is more appropriate. The 4BP static creep and dynamic tests are sufficient methods for determining the rheological parameters for materials designed for flexible pavements. In the 4BP dynamic test, we determined relationships between damping and viscosity coefficients, showing material variability depending on the test temperature.

Superpave Models: Predicting Performance during Design and Construction

1996 ◽  
Vol 1545 (1) ◽  
pp. 105-112
Author(s):  
Gerald A. Huber ◽  
Xishun Zhang ◽  
Robin Fontaine
Keyword(s):  
Prediction Models ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Engineering Properties ◽  
Design System ◽  
Widespread Application ◽  
Premature Failure ◽  
The Impact

The Strategic Highway Research Program (SHRP) spent $50 million researching asphalt binders and asphalt mixtures and provided three main products: an asphalt binder specification, an asphalt mixture specification, and Superpave, an asphalt mixture design system that encompasses both the binder and mixture specification. SHRP researchers have provided tools that promise more robust asphalt mixtures with reduced risk of premature failure. Implementation of the specifications and mix design system will require overcoming several obstacles. Superpave must be demonstrated to be practical and easy to use. The impact of Superpave aggregate requirements on aggregate availability must be determined. The Superpave gyratory compaction procedure has been uniquely defined and then calibrated to traffic volume. The reasonableness of this approach must be tested in widespread application. Perhaps the largest implementation hurdle exists in the performance models. Expensive test equipment is necessary to do the performance-based tests. The performance predictions must be established as reasonable to justify the cost. A highway reconstruction project containing three Superpave Level 1 mix designs is documented including quality control done with the Superpave gyratory compactor. Superpave Level 2 performance-based tests were carried out to predict permanent deformation of the design and the mixture as constructed. The performance-based engineering properties obtained from the tests are evaluated, and the reasonableness of the performance prediction models is discussed.

Research on the Road Performance of the AC-25 Asphalt Mixtures

2012 ◽  
Vol 204-208 ◽  
pp. 1593-1598
Author(s):  
Hong Mei Li ◽  
Wen Fang Liu
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Central Layer ◽  
The Road ◽  
Road Performance ◽  
On The Road

In this paper, firstly, based on asphalt pavement central layer, the comparison with the foreign related gradation of asphalt mixtures, one typical kinds of gradations are decided; Secondly, the asphalt aggregate ratio is predicted based on professor Lin’s Theory , and five asphalt aggregate ratio are selected. Finally, the road performance of asphalt mixture is experimented, and the road performance of five asphalt aggregate ratio is analyzed. As a result, we can predict the range of the optimum asphalt aggregate ratio based on the road performance.

scholarly journals Deformation Parameters and Fatigue of the Recycled Asphalt Mixtures

2015 ◽  
Vol 11 (2) ◽  
pp. 115-120
Author(s):  
Juraj Šrámek
Keyword(s):  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Test Method ◽  
Traffic Load ◽  
Bending Test ◽  
Recycled Asphalt ◽  
The Road ◽  
Dynamic Methods ◽  
Deformation Complex

Abstract The deformational properties of asphalt mixtures measured by dynamic methods and fatigue allow a design the road to suit the expected traffic load. Quality of mixtures is also expressed by the resistance to permanent deformation. Complex modulus of stiffness and fatigue can reliably characterize the proposed mixture of asphalt pavement. The complex modulus (E*) measurement of asphalt mixtures are carried out in laboratory of Department of Construction Management at University of Žilina by two-point bending test method on trapezoid-shaped samples. Today, the fatigue is verified on trapezoid-shaped samples and is assessed by proportional strain at 1 million cycles (ε6). The test equipment and software is used to evaluate fatigue and deformation characteristics.

scholarly journals Effects of Aggregate Mesostructure on Permanent Deformation of Asphalt Mixture Using Three-Dimensional Discrete Element Modeling

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3601 ◽  
Author(s):  
Deyu Zhang ◽  
Linhao Gu ◽  
Junqing Zhu
Keyword(s):  
Surface Texture ◽  
Deformation Behavior ◽  
Negative Impact ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Discrete Element ◽  
Asphalt Mixtures ◽  
Creep Tests

This paper investigated the effects of aggregate mesostructures on permanent deformation behavior of an asphalt mixture using the three-dimensional (3D) discrete element method (DEM). A 3D discrete element (DE) model of an asphalt mixture composed of coarse aggregates, asphalt mastic, and air voids was developed. Mesomechanical models representing the interactions among the components of asphalt mixture were assigned. Based on the mesomechanical modeling, the uniaxial static load creep tests were simulated using the prepared models, and effects of aggregate angularity, orientation, surface texture, and distribution on the permanent deformation behavior of the asphalt mixtures were analyzed. It was proven that good aggregate angularity had a positive effect on the permanent deformation performance of the asphalt mixtures, especially when approximate cubic aggregates were used. Aggregate packing was more stable when the aggregate orientations tended to be horizontal, which improved the permanent deformation performance of the asphalt mixture. The influence of orientations of 4.75 mm size aggregates on the permanent deformation behavior of the asphalt mixture was significant. Use of aggregates with good surface texture benefitted the permanent deformation performance of the asphalt mixture. Additionally, the non-uniform distribution of aggregates had a negative impact on the permanent deformation performance of the asphalt mixtures, especially when aggregates were distributed non-uniformly in the vertical direction.

scholarly journals Effectiveness of Micro- and Nanomaterials in Asphalt Mixtures through Dynamic Modulus and Rutting Tests

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Hui Yao ◽  
Zhanping You
Keyword(s):  
Dynamic Modulus ◽  
Mechanical Performance ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Test Results ◽  
Modified Asphalt ◽  
Overall Performance ◽  
Carbon Microfiber

The objectives of this research are to use micro- and nanomaterials to modify the asphalt mixture and to evaluate the mechanical performance of asphalt mixtures. These micro- and nanomaterials, including carbon microfiber, Nanomer material, nanosilica, nonmodified nanoclay, and polymer modified nanoclay, were selected to blend with the control asphalt to improve the overall performance of the modified asphalt binders and mixtures. The microstructures of original materials and asphalt binders were observed by the field emission scanning electron microscope (FE-SEM). The mixture performance tests were employed to evaluate the resistance to rutting and permanent deformation of the modified asphalt mixtures. Test results indicate that(1)the dynamic modulus of micro- and nanomodified asphalt mixtures improved significantly;(2)the rutting susceptibility of the modified asphalt mixtures was reduced significantly compared to that of the control asphalt mixture;(3)the microstructures of modified asphalt binders were different from the control asphalt, and the structures determine the improvement in the performance of modified asphalt mixtures. These results indicate that the addition of micro- and nanomaterials enhanced the rutting performance and strength of asphalt mixtures. In addition, the analysis of variance (ANOVA) was used to analyze the modifying effects of micro- and nanomaterials on the performance.

The Triaxial Test Research of Asphalt-Rubber Mixture

2012 ◽  
Vol 598 ◽  
pp. 603-607 ◽  
Author(s):  
Lan Wang ◽  
Xiao Hui Meng ◽  
Li Qing Pan ◽  
Ji Quan Zhang
Keyword(s):  
Triaxial Test ◽  
Asphalt Mixture ◽  
Confining Pressure ◽  
The United States ◽  
Test System ◽  
Rubber Mixture ◽  
Factors Affecting ◽  
Modified Asphalt ◽  
Asphalt Rubber ◽  
Shear Performance

In order to evaluate the shear performance of the rubber powder modified asphalt mixture, we do the triaxial test of Asphalt-Rubber mixture at specified temperature, which use the United States GCTS STX-100 two-way vibration triaxial test system. Through the result of the test, we analysis the factors affecting the shear resistance of asphalt mixture such as modification agent,confining pressure, gradation type and also get the mechanical properties of the asphalt mixture in the triaxial stress state.

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