scholarly journals Assessment of Rutting Resistance and Healing for Stone Matrix Asphalt Concrete (SMAC)

2019 ◽  
Vol 11 (2) ◽  
pp. 60-69
Author(s):  
Saad Issa Sarsam ◽  
Shahed Mahmood Khalil

Stone Matrix Asphalt Concrete (SMAC) is known as tough, stable, rut-resistant mixture. In this investigation, SMAC was prepared in the laboratory using gap graded aggregates, asphalt cement, mineral filler and coal fly ash as stabilizing agent. Specimens were prepared using static compaction to the target density based on asphalt content for each case. The prepared Specimens were subjected to the 1200 repeated compressive stresses at 25 ºC under various stress levels using the pneumatic repeated load system PRLS. Specimens were subjected to microcrack healing process by external heating for 120 minutes at 60 °C, then it practices another cycle of repeated compressive stresses. The resilient modulus, permanent deformation, and rutting resistance under three levels of stress have been assessed. It was concluded that the resilient modulus Mr increases by (66, 50 and 31) %, (36, 50 and 31) % and (62, 37 and 69) %, while the permanent deformation decreases by (25, 11.4 and 25) %, (19, 31.6 and 14.5) % and (14, 9 and 8.3) % after implementation of fly ash at (OAC-0.5, OAC and OAC+0.5) % binder content under (0.068, 0.138 and 0.206) MPa of repeated compressive stress respectively. The resilient modulus increased by (17.6, 15.3, 10.5) % , (42.8, 51, 37.5) % and (18.7, 25, 23.6) %  and the permanent deformation decline by (3.52, 31.66, 6.25) % under repeated compressive stresses of (0.068, 0.138, 0.206) MPa at (25 °C) after healing for mix with (4.6, 5.1, 5.6) % asphalt content  respectively when compared with mixtures before healing.

2020 ◽  
Vol 26 (5) ◽  
pp. 128-142
Author(s):  
Shahad Mahmood Khalil ◽  
Saad I. Sarsam

Stone Matrix Asphalt (SMA) is a gap-graded asphalt concrete hot blend combining high-quality coarse aggregate with a rich asphalt cement content. This blend generates a stable paving combination with a powerful stone-on-stone skeleton that offers excellent durability and routing strength. The objectives of this work are: Studying the durability performance of stone matrix asphalt (SMA) mixture in terms of moisture damage and temperature susceptibility and Discovering the effect of stabilized additive (Fly Ash ) on the performance of stone matrix asphalt (SMA) mixture. In this investigation, the durability of stone matrix asphalt concrete was assessed in terms of temperature susceptibility, resistance to moisture damage, and sensitivity to the variation in asphalt content. Specimens of 63.5 mm height and 102 mm diameter were compacted using the Marshall method at 150 °C. The optimum asphalt content was determined. Additional specimens were prepared with (0.5) percent below and above the OAC requirement. Specimens were subjected to indirect tensile strength (ITS) determination at (25 and 40) °C, and double punch shear strength determination. Another group of specimens was subjected to Marshall properties determination and to moisture damage. It was observed that stone matrix asphalt exhibit lower sensitivity to the change in asphalt content from the resistance to moisture damage and temperature susceptibility points of view. However, the tensile and shear properties exhibit significant sensitivity to the variation in asphalt content.


Author(s):  
Alireza Ameli ◽  
Javad Maher ◽  
Amir Mosavi ◽  
Narjes Nabipour ◽  
Rezvan Babagoli ◽  
...  

The current study assessed the influence of Anti Stripping Agents (ASA), Ground Tire Rubber (GTR) and waste polyethylene terephthalate (PET) on performance behavior of binder and Stone Matrix Asphalt (SMA) mixtures. Through this paper, the 85/100 penetration grade bitumen was utilized as original bitumen. Also, three liquid ASA’s (ASA (A), ASA (B), ASA (C)) were used as a mixture modifier. For this purpose, softening point, penetration, rotational viscosity, Dynamic Shear Rheometer, Multi Stress Creep Recovery (MSCR) and Linear Amplitude Sweep (LAS) tests were implemented to investigate the rheological properties of modified bitumen. For evaluating the behavior of modified mixtures several tests such as; Resilient Modulus, Tensile Strength, dynamic creep, wheel track and four-point beam fatigue tests were implemented. Based on MSCR test results, utilization of mentioned polymers enhanced the elasticity of bitumens and therefore the permanent deformation resistance of binders increases. Also by the addition of PET percentage, the rutting resistance improves. Results indicated that utilization of ASAs, PET and Crumb Rubber (CR) enhance the Resilient Modulus (Mr), Indirect Tensile Strength (ITS), rutting resistance, fatigue life and Fracture Energy (FE) of asphalt mixtures. Also based on results, modification of binder by PET/CR with a ratio of 50%/50% and ASA (B) have the highest fatigue life which indicates that this mixture has highest resistance against fatigue cracking.


Author(s):  
Hongbin Xie ◽  
Donald E. Watson ◽  
E. Ray Brown

Current stone matrix asphalt (SMA) design guidelines list two compaction options to design SMA, 50 blows Marshall or 100 gyrations with the Superpave® gyratory compactor (SGC). However, some states have found that 100 gyrations with the SGC is excessive for their materials. In this study a lower compaction level of 65 gyrations was used to compare with the standard 100 gyrations to design SMA mixtures. Results showed that mixtures designed by 65 gyrations had an average of 0.7% higher optimum asphalt content and 1.5% higher voids in mineral aggregate (VMA) than those designed by 100 gyrations. All mixtures designed by 65 gyrations met the minimum asphalt content and VMA requirements for SMA, whereas only eight of 15 mixtures designed by 100 gyrations met those two requirements. Compaction at 100 gyrations resulted in an additional 0.62% average aggregate breakdown at the critical sieve as compared with 65 gyrations. SMA mixtures designed by 65 gyrations and 100 gyrations had an average asphalt pavement analyzer rut depth of 3.9 mm and 3.1 mm, respectively. Thirteen of 15 mixtures designed by 65 gyrations performed well if 5.0 mm was set as the maximum allowed rut depth. On the basis of this study, 65 gyrations can be used to design a more durable SMA mixture, while still maintaining the good rutting resistance that SMA mixtures are noted for. The successful design by 65 gyrations for all five aggregates in this study indicates that a lower design compaction level may allow the use of more aggregate sources for SMA mixtures.


2019 ◽  
Vol 8 (4) ◽  
pp. 168-174
Author(s):  
Saad Issa Sarsam ◽  
Mohammed Chaloob Saleem

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.


Author(s):  
E. Ray Brown ◽  
John E. Haddock ◽  
Campbell Crawford

The use of stone matrix asphalt (SMA) has continued to increase in the United States since its initial application in 1991. This preference for SMA has been linked to its ability to withstand heavy traffic without rutting. The antirutting capability of SMA is normally accredited to the presence of a stone-on-stone aggregate skeleton in the mixture. However, the mortar in an SMA mixture is also important. The mortar is composed of fine aggregate, filler, asphalt cement, and a stabilizing additive. Work to characterize SMA mortars is detailed. For testing purposes, the mortar was broken into separate phases, total mortar and fine mortar. The fine mortar was tested using the Superior Performing Asphalt Pavements system (Superpave) binder tests. The total mortar was tested using the bending beam rheometer, resilient modulus, indirect tensile test, and Brookfield vis-cometer. The results indicate that the fine and total mortars are closely related. In addition, it was determined that at least some of the Superpave tests can be used to characterize SMA mortars. It is recommended that further testing be completed and specification criteria be established for the mortar.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Alireza Azarhoosh ◽  
Mehdi Koohmishi ◽  
Gholam Hossein Hamedi

The use of recycled concrete aggregate (RCA) as a part of coarse aggregates in asphalt pavements confers economic and environmental benefits. Coarse RCA (CRCA) has inferior mechanical and physical properties compared to natural aggregates due to very porous and weakly adhered cement mortar. In this study, CRCA surfaces were coated with waste plastic bottles (WPB) and used at 15%, 30%, and 50% in the asphalt concrete. The Marshall, stiffness modulus, and dynamic creep tests were performed to determine the strength of hot mix asphalts against rutting. The results revealed that the use of untreated CRCA reduced the Marshall quotient and the rutting resistance of the asphalt concrete. The results of the stiffness modulus and dynamic creep tests indicated that CRCA incorporation increased permanent deformation in the tested specimens due to the reduction of asphalt concrete stiffness. However, the asphalt concrete containing treated CRCA had lower permanent deformation because WPB promotes CRCA stability by penetrating its void and reinforcing cement mortar. Furthermore, by raising the temperature, the strength of all asphalt concretes decreased against rutting, and the reduction rate was higher in the modified specimens.


2018 ◽  
Vol 1 (3) ◽  
pp. 679-688
Author(s):  
Ondriani Ondriani ◽  
Sofyan M. Saleh ◽  
Muhammad Isya

Abstract: The cause of damage and strength reductionon highway flexible pavement isthe low strength and durability on the wear layer. To cope withthis problem, it is necessary to add some particular additivethat can increase the asphalt concrete performance. One of the additional material that can be used are plastic. Stone ash, cement and fly ash has been commonly used as a filler in asphalt mixture. But these kind of filler was hard to get and the price were relatively expensive. The coconut fiber ash wich has a specific grafity greater than asphalt is expected to be one alternative. This research aims to determine the influence of plastic wastecombination substitution into the asphalt pen. 60/70 and the use of coconut fiber ash as filler on AC-WC mixture performance. The plastic used in this research is polyethylene terephthalate, polypropylene and polystyrene. The early stages of this research is to find the optimum asphalt content (OAC). After OAC obtained, then the specimens were mixed without and with the combination substitution of plastic waste as much as 2.7%; 4.7%; 6.7% against the weight of  asphalt on OAC + 0.5% with and without the coconut fiber ash as a filler. The study results showed the use of plastic waste combination and the coconut fiber ash can not improve the durability value. The highest value of durability obtained at 4.7% combination substitution of plastic waste, it was 77.53%, While the lowest was in substitution of 6.7% plastic waste combination with 38.27% coconut fiber  ash as a filler. The duration value of AC-WC mixture with plastic waste combination substitution and the use of coconut fiber ash filler did not meet the requirement that is 90%.Abstrak: Penyebab kerusakan dan penurunan kekuatan perkerasan lentur jalan raya adalah rendahnya kekuatan dan keawetan di dalam lapisan aus. Untuk menanggulangi hal ini dibutuhkan suatu bahan tambah yang dapat meningkatkan lapis aspal beton. Salah satu bahan tambah yang dapat di gunakan adalah plastik. Abu batu, semen dan fly ash sudah biasa digunakan sebagai filler dalam campuran aspal. Tetapi, jenis filler tersebut susah didapatkan dan harganya relatif mahal. Abu serabut kelapa yang memiliki berat jenis lebih besar dari aspal, diharapkan dapat menjadi alternatifnya. Penelitian ini bertujuan untuk mengetahui nilai durabilitas campuran AC-WC menggunakan kombinasi limbah plastik dan abu serabut kelapa. Plastik yang digunakan pada penelitian ini adalah Polyethylene Terephthalate, Polypropylenedan Polystyrene. Tahap awal penelitian ini adalah mencari kadar aspal optimum (KAO). Setelah KAO didapat kemudian dilakukan pembuatan benda uji tanpa dan dengan substitusi kombinasi limbah plastik sebesar 2,7%; 4,7%; 6;7% terhadap berat aspal pada KAO + 0,5% tanpa dan dengan abu serabut kelapa sebagai filler. Hasil penelitian menunjukkan penggunaan kombinasi limbah plastik tidak dapat meningkatkan nilai durabilitas. Nilai durabilitas tertinggi didapat pada substitusi kombinasi limbah plastik 4,7% yaitu 77,53% sedangkan yang terendah terdapat pada subtitusi kombinasi limbah plastik 6,7% dengan filler abu serabut kelapa yaitu 38,27%. Nilai Durabilitas campuran AC-WC dengan substitusi kombinasi limbah plastik   dan penggunaan abu serabut kelapa sebagai filler tidak memenuhi syarat yaitu 90%.


2020 ◽  
Vol 26 (2) ◽  
pp. 159-175
Author(s):  
Mustafa Shakir Mahdi ◽  
Prof. saad Isa Sarsam

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.


2018 ◽  
Vol 2 (01) ◽  
pp. 87
Author(s):  
Muhammad Sadillah ◽  
M. Zainul Arifin ◽  
Achmad Wicaksono

In an effort to increase the strength of mixed asphalt concrete structure ( AC-WC ) in addition to the use of hot asphalt mixture with new specification, the selection of material type used is very important. In addition to asphalt, both coarse and fine aggregates and fillers are one component in a pavement construction that has a large role. Therefore further research is needed on the influence of temperature variation and percentage of filler fly ash to the modulus of r esilien which is good so that it can be applied and able to overcome the damages. In this research is divided into 3 (three) stages namely (1) the selection of materials; (2) the preparation of the specimen; (3) research and data analysis. Asphalt concrete mixed test (AC-WC) showed that Asphalt Optimum (KAO) content with 5.5% asphalt content with VIM value of 3.70%, VMA of 19.00%, Stability of 1,152.93 kg, Flow of 2.78 mm and MQ of 417.39 kg/mm. The result of mixed asphalt concrete (AC-WC) asphalt with filler fly ash test showed that the optimum mixture content was 7% filler content with VIM value 4,21%, VMA 19,21%, Stability 1326.10 kg, Flow of 3.69 mm and MQ of 360.13 kg/mm. Dalam upaya meningkatkan kekuatan struktur campuran beton aspal lapisan aus (AC-WC) selain perlu adanya penggunaan campuran beraspal panas dengan spesifikasi baru, pemilihan jenis material yang digunakan adalah sangat penting. Selain aspal, agregat baik kasar maupun halus serta filler adalah salah satu komponen dalam suatu konstruksi perkerasan jalan yang mempunyai peranan besar. Oleh karena itu diperlukan penelitian lebih lanjut mengenai pengaruh variasi temperatur dan prosentase filler fly ash terhadap modulus resilien yang baik sehingga dapat diterapkan dan mampu mengatasi kerusakan-kerusakan. Dalam penelitian ini terbagi dalam 3 (tiga) tahapan yaitu (1) tahapan pemilihan bahan; (2) tahap persiapan benda uji; (3) tahap penelitian dan analisis data. Hasil pengujian campuran aspal beton lapis aus (AC-WC) menunjukan bahwa Kadar Aspal Optimum (KAO) yaitu dengan kadar aspal 5,5% dengan nilai VIM sebesar 3.70%, VMA sebesar 19,00%, Stabilitas sebesar 1.152,93 Kg, Flow sebesar 2,78 mm dan MQ sebesar 417,39 Kg/mm. Hasil pengujian campuran aspal beton lapis aus (AC-WC) dengan penggantian filller fly ash menunjukan bahwa kadar campuran optimum yaitu dengan kadar filler 7% dengan nilai VIM sebesar 4,21%, VMA sebesar 19,21%, Stabilitas sebesar 1326.10 Kg, Flow sebesar 3,69 mm dan MQ sebesar 360.13 Kg/m.


Jurnal CIVILA ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 124
Author(s):  
Mohammad Zainudin Abdillah ◽  
Dwi Kartikasari

 Asphalt concrete wearing course as a wear layer in highway pavement layer, Is the top layer in flexible pavement. In this research will be discussed on the use of Portland cement filler as a reference to compare filler replacement with fly ash and powdered brick with 100% fly ash, 100% powdered brick and 50% fly ash: 50% powder brick. The first step after the aggregate testing, the asphalt and filler material to be used, followed by the manufacture of the specimen with the specified asphalt content. After obtaining the optimum asphalt content for each different filler variation, a Marshall test was performed to obtain flow stability and density values. In this research we get the optimum asphalt content value of 5,5% for each specimen. The result of this research mixed with good quality using 100% Portland cement filler stability value of 112.19 kg and the lowest using filler 100% fly ash but the result still meet the specifications of clan. While the MQ value with 100% filler of brick powder under specification of Bina Marga is 213. So it can be concluded that a good filler for asphalt concrete wearing course mixture is with Portland cement.


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