Investigating Permanent Deformation of Recycled Asphalt Concrete Containing Waste Oils as Rejuvenator Using Response Surface Methodology (RSM)

2020 ◽  
Author(s):  
Hasan Taherkhani ◽  
Farid Noorian
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Recycled Asphalt ◽  
Waste Oils

Mitigation of permanent deformation in base layer containing recycled asphalt aggregates

2013 ◽  
Vol 40 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Jean-Pascal Bilodeau ◽  
Guy Doré ◽  
Jonas Depatie
Keyword(s):  
Asphalt Concrete ◽  
Deformation Behaviour ◽  
Permanent Deformation ◽  
Design Procedure ◽  
Base Layer ◽  
Repeated Loading ◽  
Recycled Asphalt ◽  
Thickness Increase ◽  
Permanent Strain ◽  
Pavement Base

The use of recycled asphalt pavement (RAP) aggregates as replacement for new materials in the pavement base weakens the layer in regards to the resistance to permanent deformation under repeated loading. A mechanistic based design procedure is proposed to ensure that base layers containing RAP particles have a similar rutting behaviour to base layers made of virgin aggregates. The design procedure allows calculating an asphalt concrete thickness increase that is based on permanent deformation behaviour of base materials. The calculation approach is based on multistage triaxial permanent deformation tests performed on granular material samples with varied RAP content. The tests allowed proposing an equation that relates permanent strain rate, RAP content, and deviatoric stress, which is the basis of the design procedure. Design charts are proposed to select adequate thickness increase for the asphalt concrete layer according to the expected RAP content in the base layer and asphalt concrete modulus.

scholarly journals Influence of Additives on Permanent Deformation and Resilient Modulus of Recycled Asphalt Concrete

2020 ◽  
Vol 26 (2) ◽  
pp. 159-175
Author(s):  
Mustafa Shakir Mahdi ◽  
Prof. saad Isa Sarsam
Keyword(s):  
Carbon Black ◽  
Compressive Stress ◽  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Styrene Butadiene

Tests were performed on asphalt concrete specimens with (101.6 mm in diameter and 101.6 mm in height), and the results were implemented for calculating permanent deformation and resilient modulus under repeated compressive stress with different levels of stresses (0.068, 0.138 and 0.206) MPa at 40 ºC. Two types of additives namely (carbon black-asphalt) and (SBR-asphalt) were tried as rejuvenators with three percentages of (0.5, 1 and 1.5) % by weight of asphalt cement along with two ratios of AC (1 and 2) % have been implemented as rejuvenator and blended with the reclaimed asphalt concrete. Aged materials were obtained from the site. 100% Reclaimed Asphalt Pavement material from the reclaimed mixture is implemented. A set of (3) specimens were prepared for every mixture; three specimens were tested under (repeated compressive stress) at each level of stress. The objective of this work was to study the effect of two types of additives (Styrene-Butadiene-Rubber (SBR) and carbon black) on the performance of recycled asphalt concrete mixture. It was concluded that the Resilient modulus (Mr) at (0.138 and 0.206) MPa stress level decreases by (14, 22 and 8) % and (22, 34 and 11) for reclaimed and recycle mixtures with (carbon black-asphalt and SBR-asphalt) respectively when compared with that at 0.068 MPa. Permanent deformation for recycled mixtures with (carbon black-asphalt and SBR-asphalt) increased by (65.9, 4.54) %, (146.6, 27.2) % and (79, 5.5) % at level of stresses (0.068, 0.138 and 0.206) MPa respectively when compared to reclaimed mixture.

scholarly journals Monitoring Micro Crack Healing Phenomena in Recycled Asphalt Concrete

2020 ◽  
Vol 1 (4) ◽  
pp. 1-6
Author(s):  
Saad Issa Sarsam
Keyword(s):  
Service Life ◽  
Carbon Black ◽  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Styrene Butadiene Rubber ◽  
Shear Stresses ◽  
Crack Healing ◽  
Recycling Process ◽  
Recycled Asphalt ◽  
Testing Techniques

Asphalt concrete usually practices cracking and distress during its service life. However, recycling process as well as crack healing phenomena can enhance the physical properties and extend the pavement service life. This investigation is concerned with monitoring the microcrack healing of recycled asphalt concrete through its influence on deformation measurement under three testing techniques, repeated (compressive, tensile and shear stresses). Reclaimed asphalt concrete mixture was recycled with [carbon black-asphalt] and [Styrene Butadiene Rubber (SBR)-asphalt] rejuvenators. Specimens have been tested with the aid of the pneumatic repeated load system (PRLS). The repeated loading of the three testing techniques was terminated after 1000 load repetitions, and the specimens could heal by external heating at 60°C for 120 minutes. Specimens were returned to the (PRLS) and subjected to another run of repeated stresses application after healing. It was concluded that the deformation increases after recycling process while it declines after microcrack healing regardless of the testing technique adopted. The deformation declines by (31.8, 5.8 and 19)%, (43 ,49 and 24 )% and (44 ,10 and 13 )% under three level of repeated compressive stresses of (0.068, 0.138, and 0.206) MPa at (40 °C) after healing cycle for reclaimed and recycled mixture with (carbon black-asphalt) and (SBR-asphalt) respectively when compared with permanent deformation before the healing cycle. The permanent deformation under repeated punching shear and indirect tensile stresses declines after microcrack healing by (32, 26 and 25.7) % and (73, 78.7 and 78.2) % for reclaimed, recycled with (carbon black-asphalt) and recycled with (SBR-asphalt) mixtures respectively.

scholarly journals Assessing the Flexibility of Recycled Asphalt Concrete Pavement

2019 ◽  
Vol 8 (4) ◽  
pp. 168-174
Author(s):  
Saad Issa Sarsam ◽  
Mohammed Chaloob Saleem
Keyword(s):  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Environmental Benefits ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Applied Loading ◽  
Compressive Stresses ◽  
Asphalt Concrete Pavement

Utilizing reclaimed asphalt pavement (RAP) in new asphalt mixtures has increased in recent years because of its economic and environmental benefits. The flexibility of the recycled asphalt concrete (with cutback and emulsion) in terms of resilient modulus (Mr), rutting resistance, and permanent microstrain have been investigated in this work. Cylindrical specimens of 102 mm in diameter and 102 mm in height have been prepared from the recycled mixture after the short-term aging process. Specimens were subjected to 1200 repeated compressive stresses at (25) ºC. The vertical permanent microstrain was monitored through video capture. It was concluded that RAP mixture can hold the applied loading with minimal permanent deformation as compared to the recycled mixtures. The resilient modulus is lower by (24 and 39) % for mixes recycled with cutback and emulsion respectively as compared to that of RAP. The rate of strain (slope) increases by 11 % and 4 % when cutback and emulsion were implemented as recycling agent respectively as compared to that for RAP mixture.

scholarly journals Influence of Liquid Asphalt on Resilient Modules and Permanent Deformation of Recycled Asphalt Concrete

2019 ◽  
Vol 25 (9) ◽  
pp. 76-91
Author(s):  
Mohammed Chaloob Saleem AL-Shujairy ◽  
Saad Isaa Sarsam
Keyword(s):  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Water Bath ◽  
Repeated Loading ◽  
Recycled Asphalt ◽  
Average Value ◽  
Weight Content ◽  
Three Samples ◽  
Indirect Tensile

Tests were performed on Marshall samples and were implemented for permanent deformation and resilient modulus (Mr) under indirect tensile repeated loading (ITRL), with constant stress level. Two types of liquid asphalt (cutback and emulsion) were tried as recycling agents, aged materials that were reclaimed from field (100% RAP), samples were prepared from the aged mixture, and two types of liquid asphalt (cutback and emulsion) with a weight content of 0.5% were utilized to prepare a recycled mixture. A group of twelve samples was prepared for each mixture; six samples were tested directly for ITRL test (three samples at 25˚C and three samples at 40˚C), an average value for ITRL for every three samples was calculated (ITRL for unconditioned samples). The other six samples were placed in volumetric flask 4000-ml heavy- wall glass filled with water at 25˚C under a vacuum pressure of (3.74 kPa) for 5 to 10 minutes. Then the samples were put in deep freeze for 16 hours at -18˚C. The samples were frozen then were transported to a water bath at 60ºC for 24 hours. Then they were soaked in a water bath for 1 hour at 25ºC and tested for the ITRL test (three samples at 25˚C and three samples at 40˚C), the average value of ITRL for every three samples was calculated (ITRL for conditioned samples). It was concluded that the reduction in (Mr) at the Conditioned test as compared to the Unconditioned test was (29.5%, 22.27% and 9.09%) at 25˚C, while at 40˚C, the reduction was (21.28%, 15.53%, and 17.89%) for aged and recycled mixtures with (cutback), and (emulsion) respectively. The change in permanent deformation at the Conditioned test as compared to Unconditioned one was (76.19%, 75.61% and 53.22%) at 25˚C, while at 40˚C it was (56.48%, 35.19%, and 78.33%) for aged and recycled mixtures with (cutback), and (emulsion) respectively.  

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