Permanent Deformation Model Based on Shear Properties of Asphalt Mixtures

In the asphalt foaming process, the foaming water content (FWC) controls the formation and characteristics of water bubbles. These water bubbles are expected to be expelled from the foamed warm mix asphalt (WMA) during mixing and compaction. However, foaming water may not be completely expelled, rather some of the microbubbles may be trapped in the foamed WMA even after compaction. These microbubbles, or undissipated water, can diffuse over time and cause damage to the foamed WMA. To this end, this study has determined the effects of foaming on the fatigue, moisture damage, and permanent deformation characteristics of foamed WMA. Foamed asphalt and mixtures were designed with varying FWCs and they were tested using linear amplitude sweep, multiple stress creep recovery, four-point flexural beam, and Hamburg wheel tracking tests. Primarily, asphalt foaming dynamics were assessed with a laser-based non-contact method. A simplified viscoelastic continuum damage concept and a three-phase permanent deformation model were used for damage evaluation. The study reveals that foaming softens the binder, which results in slightly higher rutting and moisture susceptibility, though an equivalent or slightly improved fatigue characteristic compared with the regular hot mix asphalt.

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

Sustainability ◽

10.3390/su13063315 ◽

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.

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Effect of Rubberized Bitumen Blending Methods on Permanent Deformation of SMA Rubberized Asphalt Mixtures

Advances in Materials Science and Engineering ◽

10.1155/2016/4395063 ◽

2016 ◽

Vol 2016 ◽

pp. 1-14 ◽

Cited By ~ 4

Author(s):

Herda Yati Katman ◽

Mohd Rasdan Ibrahim ◽

Mohamed Rehan Karim ◽

Suhana Koting ◽

Nuha Salim Mashaan

Keyword(s):

Creep Behaviour ◽

Permanent Deformation ◽

Asphalt Mixtures ◽

Creep Model ◽

Materials Testing ◽

Wet Process ◽

Test Conditions ◽

Dynamic Creep ◽

Different Temperatures ◽

Stone Mastic Asphalt

This study aims at comparing the permanent deformation of Stone Mastic Asphalt (SMA) rubberized asphalt mixtures produced by the wet process. In this study, rubberized binders were prepared using two different blending methods, namely, continuous blend and terminal blend. To study the creep behaviour of control and rubberized asphalt mixtures, the dynamic creep test was performed using Universal Materials Testing Apparatus (UMATTA) at different temperatures and stress levels. Zhou three-stage creep model was utilized to evaluate the deformation characteristics of the mixtures. In all test conditions, the highest resistance to permanent deformation is showed by the rubberized mixtures produced with continuous blend binders. This study also reveals that the permanent deformation of rubberized mixtures cannot be predicted based on the characteristics of the rubberized binders.

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Virtual design of asphalt mixtures using a growth and contact model based on realistic aggregates

Construction and Building Materials ◽

10.1016/j.conbuildmat.2022.126322 ◽

2022 ◽

Vol 320 ◽

pp. 126322

Author(s):

Can Jin ◽

Yuanjie Feng ◽

Xu Yang ◽

Pengfei Liu ◽

Zhongjun Ding ◽

...

Keyword(s):

Asphalt Mixtures ◽

Contact Model ◽

Virtual Design ◽

Model Based

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Use of Superpave Technology for Design and Construction of Rubberized Asphalt Mixtures

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1583-09 ◽

1997 ◽

Vol 1583 (1) ◽

pp. 71-81 ◽

Cited By ~ 9

Author(s):

H. Barry Takallou ◽

Hussain U. Bahia ◽

Dario Perdomo ◽

Robert Schwartz

Keyword(s):

Fatigue Behavior ◽

Permanent Deformation ◽

Performance Testing ◽

Fatigue Cracking ◽

Asphalt Mixtures ◽

Mix Design ◽

Asphalt Rubber ◽

Constant Height ◽

Overlay Design ◽

Gyratory Compaction

The effect of different mixing times and mixing temperatures on the performance of asphalt-rubber binder was evaluated. Four different types of asphalt-rubber binders and neat asphalt were characterized using the Strategic Highway Research Program (SHRP) binder method tests. Subsequently, mix designs were carried out using both the SHRP Levels I and II mix design procedures, as well as the traditional Marshall mix design scheme. Additionally, performance testing was carried out on the mixtures using the Superpave repetitive simple shear test at constant height (RSST-CH) to evaluate the resistance to permanent deformation (rutting) of the rubberized asphalt mixtures. Also, six rectangular beams were subjected to repeated bending in the fatigue tester at different microstrain levels to establish rubberized asphalt mixtures’ resistance to fatigue cracking under repeated loadings. The results indicate that the Superpave mix design produced asphalt-rubber contents that are significantly higher than values used successfully in the field. Marshall-used gyratory compaction could not produce the same densification trends. Superpave mixture analysis testing (Level II) was used successfully for rubberized asphalt mixtures. Results clearly indicated that the mixture selected exhibited acceptable rutting and fatigue behavior for typical new construction and for overlay design. Few problems were encountered in running the Superpave models. The results of the RSST-CH indicate that rubber-modified asphalt concrete meets the criteria for a maximum rut depth of 0.5 in.; and more consistent results were measured for fatigue performance analysis using the repeated four-point bending beam testing (Superpave optional torture testing). The cycles to failure were approximately 26,000 at 600 microstrain.

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

Materials and Structures ◽

10.1617/s11527-021-01790-y ◽

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.

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