scholarly journals Experimental Investigation on Asphalt Binders Ageing Behavior and Rejuvenating Feasibility in Multicycle Repeated Ageing and Recycling

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yihua Nie ◽  
Shiheng Sun ◽  
Yajun Ou ◽  
Chenyang Zhou ◽  
Kunli Mao
Keyword(s):  
Ageing Time ◽  
Asphalt Mixture ◽  
Asphalt Binders ◽  
Cycle Number ◽  
Reclaimed Asphalt ◽  
Pavement Materials ◽  
Before And After ◽  
Infrared Spectral ◽  
Repeated Use ◽  
Rheological Indices

Multicycle repeated utilization of reclaimed asphalt pavement (RAP) is a quite recent development of sustainable pavement materials technology. To investigate ageing rules and recycling possibility of asphalt binders in repeatedly used asphalt mixture, virgin asphalt AH-70 samples were heated by the rolling thin film oven test (RTFOT) at 163°C, respectively, for 40, 85, 180, 240, and 300 minutes to simulate different ageing degrees, and then the aged ones were rejuvenated by adding a self-made rejuvenator. This ageing and recycling process was repeated altogether for 5 cycles to simulate repeated use of RAP binders. In repeated recycling, rejuvenator contents for different cycle numbers or ageing durations were not the same, and the optimum ones were initially estimated by an empirical formula and finally obtained by comparative tests. Empirical rheological tests and the infrared spectral (IR) analysis were done before and after each cycle of recycling. Results indicate that for impact on deterioration of asphalt binders, ageing time is more important than cycle number. Meanwhile, the asphalt after multicycle repeated ageing and recycling can be restored to the empirical rheological indices level of the virgin asphalt and meet specifications requirements.

scholarly journals The Effect of Aging on the Cracking Resistance of Recycled Asphalt

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Mojtaba Mohammadafzali ◽  
Hesham Ali ◽  
James A. Musselman ◽  
Gregory A. Sholar ◽  
Aidin Massahi
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Reclaimed Asphalt Pavement ◽  
Cracking Resistance ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Important Concern

Fatigue cracking is an important concern when a high percentage of Reclaimed Asphalt Pavement (RAP) is used in an asphalt mixture. The aging of the asphalt binder reduces its ductility and makes the pavement more susceptible to cracking. Rejuvenators are often added to high-RAP mixtures to enhance their performance. The aging of a rejuvenated binder is different from virgin asphalt. Therefore, the effect of aging on a recycled asphalt mixture can be different from its effect on a new one. This study evaluated the cracking resistance of 100% recycled asphalt binders and mixtures and investigated the effect of aging on this performance parameter. The cracking resistance of the binder samples was tested by a Bending Beam Rheometer. An accelerated pavement weathering system was used to age the asphalt mixtures and their cracking resistance was evaluated by the Texas Overlay Test. The results from binder and mixture tests mutually indicated that rejuvenated asphalt has a significantly better cracking resistance than virgin asphalt. Rejuvenated mixtures generally aged more rapidly, and the rate of aging was different for different rejuvenators.

Relating Adhesion and Cohesion of Asphalts to the Effect of Moisture on Laboratory Performance of Asphalt Mixtures

2005 ◽  
Vol 1901 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Kunnawee Kanitpong ◽  
Hussain Bahia
Keyword(s):  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Fundamental Properties ◽  
Water Conditioning ◽  
Before And After ◽  
Indirect Tensile ◽  
Wheel Tracking

Antistripping additives and polymer modifications are two common modifiers used to improve the fundamental properties of asphalt binders as those properties relate to the performance of asphalt mixtures. Adhesion and cohesion are two important related properties of asphalt binders that can affect asphalt mixture performance before and after water conditioning. The purpose of this study was to quantify the effects of antistripping additives and polymers on the adhesion and cohesion of binders and to relate these effects to the performance of mixtures as measured in the laboratory before and after water conditioning. The performance tests of asphalt mixtures included indirect tensile strength, uniaxial compression permanent deformation, and Hamburg wheel tracking. Asphalt mixtures were produced with different modified binders and with two aggregate types. The binders were modified with antistripping additives and polymers and by chemical treatment and oxidization methods. Granite and limestone were selected as two types of aggregate sources. The results indicate that the performance of asphalt mixtures is highly dependent on modification techniques and water conditioning. The overall performance of polymer-modified mixtures is more desirable than those of unmodified mixtures and of mixtures modified with antistripping additives. Polymers are found to improve rutting performance, adhesion, and cohesion of an asphalt binder. In contrast, the antistripping additive can improve only the adhesion without changing other properties. The results of this study also illustrate that the adhesion and cohesion of an asphalt binder are good indicators of the performance of asphalt mixtures in the laboratory when they are conditioned with water.

Relationships among Chemistry, Rheology, and Fracture/Fatigue Performance of Recovered Asphalt Binders and Asphalt Mixtures Containing Reclaimed Asphalt Pavement

2020 ◽  
Vol 2674 (10) ◽  
pp. 927-938
Author(s):  
Peyman Barghabany ◽  
Wei Cao ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Asphalt Binders ◽  
Rheological Parameters ◽  
Cracking Resistance ◽  
Reclaimed Asphalt ◽  
Four Point Bending

Because of limited amounts of natural resources, reclaimed asphalt pavement (RAP) has gained popularity in the asphalt pavement industry to meet sustainability requirements in asphalt pavement. Concerns have been raised in relation to the intermediate temperature cracking performance of asphalt mixtures containing RAP. The objective of this study was to evaluate the intermediate temperature cracking resistance of asphalt mixtures and recovered asphalt binders containing RAP. Seven plant-produced asphalt mixtures from three transportation agencies with various RAP contents and the extracted asphalt binders were evaluated with respect to intermediate temperature cracking resistance. Asphalt binder experiments included chemical and rheological characterization of recovered asphalt binders. Chemical characterization consisted of Fourier transform infrared spectroscopy and saturates/aromatics/resins/asphaltenes component analysis. Linear amplitude sweep and time sweep tests were also performed to characterize the rheological properties of asphalt binders. Asphalt mixture experiments included four-point bending beam fatigue and semi-circular bend tests. Results indicated that, as expected, asphalt mixtures with high RAP contents resulted in asphalt binders and mixtures with reduced cracking resistance. Relationships between the asphalt binder chemical and rheological parameters and asphalt mixture cracking resistance were also investigated. Asphalt binder rheological and chemical parameters were well correlated. Asphalt binder rheological parameters showed reasonable to strong relationships with the four-point bending beam fatigue test result. The work presented in this paper is part of FHWA Transportation Pooled Fund Project TPF-5(294) “Develop Mix Design and Analysis Procedure for Asphalt Mixtures Containing High RAP and/or RAS Contents.”

Effect of Rejuvenator on Porous Asphalt Mixtures Containing Reclaimed Asphalt Pavement (RAP) Material

2015 ◽  
Vol 713-715 ◽  
pp. 2673-2676 ◽  
Author(s):  
Ming Yu Zhao ◽  
Fan Shen ◽  
Li Ge Qiao ◽  
Ji Lu ◽  
Qing Jun Ding
Keyword(s):  
Asphalt Mixture ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Reclaimed Asphalt ◽  
Porous Asphalt ◽  
Pavement Materials ◽  
Pavement Recycling ◽  
Aged Binder ◽  
Different Content ◽  
Modified Functional

Based on the background of continuously increasing requirements on the performance of recycle pavement materials, the effect of rejuvenator with different content (3%, 6%, 9% and 12%) and different type on recycled porous asphalt mixture was studied in this paper. The results shown that comparing with the ordinary rejuvenator which softening the aged binder effectively, the modified functional rejuvenator can also enhance the temperature stability and deformation resistance capacity of aged asphalt. In addition, the recycled porous asphalt mixture with modified functional rejuvenator has more excellent high temperature stability, water stability and fatigue performance. The result has great significance for the development of pavement recycling technology.

scholarly journals Influence of the Skid Resistance of Ultrathin Wearing Course with Various Types of Asphalt Binders

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hongfu Liu ◽  
Teng Guo ◽  
Chenxi Yang ◽  
Yunyong Huang ◽  
Xuelian Li
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Skid Resistance ◽  
Modified Asphalt ◽  
Vehicle Loading ◽  
Before And After ◽  
Warm Mix Additives ◽  
Styrene Butadiene

Ultrathin wearing course (UTWC) has been widely applied in both asphalt pavements preventive maintenance and functional overlay. This study’s objective is to evaluate the influence of different modified asphalt binders with warm mix additives on the skid resistance of UTWC and to reveal the attenuation law of skid resistance of UTWC. Three types of modified asphalt binders (Styrene-Butadiene-Styrene- (SBS-) modified asphalt, Acrylester Rubber- (AR-) modified asphalt, and SinoTPS-modified asphalt) and sasobit warm mix asphalt additive were selected to prepare asphalt mixtures. The Model Mobile Load Simulator 3 (MMLS3) was used to simulate repeated vehicle loading and abrasion. The British Pendulum Number (BPN) and Mean Texture Depth (MTD) were chosen to evaluate the skid resistance of the UTWC. The Analysis of Range (ANOR) and Analysis of Variance (ANOVA) were used to verify the significance of asphalt binder on the antiskid performance of the UTWC. ANOR and ANOVA show that the influence of different modified asphalt binders on the skid resistance of the UTWC is significant. The SinoTPS modified asphalt mixture can maintain high texture roughness before and after abrasion, providing excellent and durable skid resistance. The influence of the addition of a warm mixing additive on the skid resistance of UTWC is not significant, and changes in microtexture mainly reflect its impact on antiskid performance. The decay curve of three modified asphalt binders of the skid resistance of the UTWC can be well fitted into an exponential function. The conclusion will play an essential role in selecting the asphalt binder in a UTWC to improve the antiskid performance.

scholarly journals Microstructural Mechanical Analysis of Warm-Mixed Reclaimed Semiflexible Pavement Materials with Interfacial Weakening Effect

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hua Tan ◽  
Weian Xuan ◽  
Huang Wenke
Keyword(s):  
Compressive Stress ◽  
Heavy Traffic ◽  
Compressive Strain ◽  
Asphalt Mixture ◽  
Element Model ◽  
Mechanical Analysis ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Pavement Materials ◽  
Pavement Material

Warm-mixed reclaimed asphalt pavement technology, as an environmental recycling method to reuse waste materials, has been widely investigated around the world. However, the skeleton of the reclaimed asphalt mixture is unstable due to the existence of the reclaimed materials. Semiflexible pavement has been successfully used in heavy traffic area due to its high rutting resistance. For combination with these two methods, a warm-mixed reclaimed semiflexible pavement material was proposed in this study. In order to investigate the interfacial weakening effect of the warm-mixed reclaimed semiflexible pavement material in a microstructural perspective, an image-based two-dimensional microstructural finite element model was presented. Results show that the maximum compressive stress of the new and RAP aggregates and cement mortar with interface is greater than that without interface and the compressive stress of the material increases when considering the interface. Besides, the maximum compressive strain of the material with interface is greater than that without interface and the strain values in the models with interface at all three positions are greater than those without interface.

scholarly journals Research on the Properties of Mineral–Cement Emulsion Mixtures Using Recycled Road Pavement Materials

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 563
Author(s):  
Łukasz Skotnicki ◽  
Jarosław Kuźniewski ◽  
Antoni Szydło
Keyword(s):  
Road Construction ◽  
Base Layer ◽  
Asphalt Emulsion ◽  
Reclaimed Asphalt ◽  
Pavement Materials ◽  
Road Pavement ◽  
Road Surfaces ◽  
Cement Binder ◽  
Pavement Structures ◽  
By Products

The reduction in natural resources and aspects of environmental protection necessitate alternative uses of waste materials in the area of construction. Recycling is also observed in road construction where mineral–cement emulsion (MCE) mixtures are applied. The MCE mix is a conglomerate that can be used to make the base layer in road pavement structures. MCE mixes contain reclaimed asphalt from old, degraded road surfaces, aggregate improving the gradation, asphalt emulsion, and cement as a binder. The use of these ingredients, especially cement, can cause shrinkage and cracks in road layers. The article presents selected issues related to the problem of cracking in MCE mixtures. The authors of the study focused on reducing the cracking phenomenon in MCE mixes by using an innovative cement binder with recycled materials. The innovative cement binder based on dusty by-products from cement plants also contributes to the optimization of the recycling process in road surfaces. The research was carried out in the field of stiffness, fatigue life, crack resistance, and shrinkage analysis of mineral–cement emulsion mixes. It was found that it was possible to reduce the stiffness and the cracking in MCE mixes. The use of innovative binders will positively affect the durability of road pavements.

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