scholarly journals Effects of Additive Materials on Indirect Tensile Strength and Moisture Sensitivity of Recycled Asphalt Pavement (RAP)

2019 ◽  
Vol 4 (2) ◽  
pp. 69-79 ◽  
Author(s):  
Soz Mohammed Ebrahim ◽  
Hardy Kamal Karim
Keyword(s):  
Tensile Strength ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Road Construction ◽  
Crumb Rubber ◽  
Indirect Tensile Strength ◽  
Moisture Sensitivity ◽  
Reclaimed Asphalt ◽  
Indirect Tensile ◽  
Additive Materials

Using reclaimed asphalt pavement with additives as part of new road construction has economic and environmental advantages. As an attempt to preserve aggregate resources and save money, and knowing the effects of the selected additive materials, this study was done in Sulaimani City. The samples of the RAP were selected from the Sulaimani municipality stockpiles. The ignition and centrifuge testing machines were used to separate the aggregate and binder of the RAP. Based on the standard deviation of the obtained asphalt content, the blend was decided to be 40% RAP and 60% new material. The aggregate tests were conducted to evaluate the characteristics of the PAR aggregate. The performance grade test was done for the reclaimed asphalt binder. Three types of additives, which were Styrene Butadiene-Styrene (SBS), Crumb Rubber (CR), and Polypropylene (PP), mixed with the reclaimed asphalt binder with three different percentages of the binder which were 3%, 5%, and 7%. Indirect Tensile Strength (ITS) test was performed to the conditioned and unconditioned mixtures. To evaluate the effects of additives on the moisture sensitivity of the reclaimed mixtures, ITS Ratios were obtained. Most of the percentages of additives decreased the ITS of the conditioned and unconditioned samples. The only percentage of the additive material increased the ITS was 5% of PP in conditioned case. However, additives did not benefit the ITS, they benefited the ITSR greatly. The best obtained ITSR for each additive material was 7% SBS, 3% CR, and 5% PP that had 99.71%, 97.1%, and 90.7%, respectively.

scholarly journals PENENTUAN KADAR AIR BAGI LAPIS PONDASI DAUR ULANG JALAN BERASPAL DENGAN FOAM BINTUMEN TERHADAP KUAT TARIK TAK LANGSUNG DAN KUAT TEAKAN BEBAS

Teknika ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. 48
Author(s):  
Donny Ariawan ◽  
Slamet Budirahardjo ◽  
Ikhwanudin Ikhwanudin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Asphalt Pavement ◽  
Green Technology ◽  
Indirect Tensile Strength ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Indirect Tensile

Jalan beraspal merupakan salah satu prasarana transportasi utama di Indonesia yang belum sepenuhnya mencapai kondisi yang aman dan nyaman dimana sering dijumpai kondisi permukaan jalan yang tidak rata, bergelombang dan berlubang yang menyebabkan ketidaknyamanan bagi penggunanya. Kegiatan perbaikan dan pemeliharaan struktur perkerasan jalan, dalam hal ini jalan beraspal, menjadi sangat penting untuk kelangsungan kegiatan transportasi. Pesatnya perkembangan teknologi di bidang transportasi telah melahirkan satu terobosan baru tentang teknologi penanganan kerusakan jalan yaitu dengan cara daur ulang lapis perkerasan aspal yang sudah ada. Metode daur ulang ini memiliki keuntungan antara lain dapat menghemat biaya, merupakan green technology, memiliki kualitas yang sama dengan material baru, dan menjaga geometris perkerasan karena tebal perkerasan yang sama. Penentuan kadar air terbaik dalam campuran foam bitumen terhadap nilai kuat tarik tak langsung (ITS) serta kuat tekan bebas (UCS) untuk campuran lapis pondasi daur ulang. Dilakukan secara bertahap, dari pengujian untuk bahan penyusun campuran yaitu agregat baru, Reclaimed Asphalt Pavement (RAP), filler, aspal, dan foam bitumen. Kemudian uji terhadap campuran padat meliputi Uji Marshall, Uji Indirect Tensile Strength (ITS) dan Uji Unconfined Compressive Strength (UCS). Kadar air dan kadar foam bitumen sangat berpengaruh terhadap kuat tarik tak langsung (Indirect Tensile Strength/ITS) serta kuat tekan bebas (Unconfined Compressive Strength/UCS) dari campuran dingin daur ulang dengan foam bitumen. Nilai ITS, TSR dan UCS yang dicapai menggunakan kadar foam 2% dan kadar air optimum terbaik yang diketahui dalam penelitian sebesar 100% terhadap Kadar Air Optimum (KAO) yaitu masing- masing 301,04 kPa, 76,36%, dan 723,49 kPa

scholarly journals Evaluation of Fatigue Potential for Crumb Rubber Modified Bitumen in Stone Mastic Asphalt Mixes

2021 ◽  
Vol 10 (3) ◽  
pp. 170-183
Author(s):  
Anusha T M ◽  
◽  
Sharath Kumar M D ◽  
Dr. H S Jagadeesh ◽  
◽  
...  
Keyword(s):  
Tensile Strength ◽  
Fatigue Test ◽  
Asphalt Pavement ◽  
Indirect Tensile Strength ◽  
Engine Oil ◽  
Reclaimed Asphalt Pavement ◽  
Test Results ◽  
Reclaimed Asphalt ◽  
Indirect Tensile ◽  
Marshall Stability

SMA is a gap graded mix composed of a high concentration of coarse aggregate that is held together in a thick asphalt film by a matrix of mineral filler and stabilizers. Since natural aggregates have become expensive, hence Reclaimed Asphalt Pavement (RAP) can be reused in pavement construction to reduce the environmental hazardous due to disposal problems. Since the RAP contains used aggregates, it is highly prone to fatigue, thermal and reflective cracking effect. Rheological and chemical properties of aged bitumen in RAP can be enhanced by use of untreated waste oils such as waste engine oil as rejuvenators. This research presents a study on fatigue performance of SMA mix with Reclaimed Asphalt Pavement (RAP) materials with and without rejuvenators and results were compared with conventional SMA mix. The materials used were first characterized by common laboratory tests. Then the three SMA mixes are tested using several laboratory test procedures: Marshall Stability, indirect tensile strength, moisture susceptibility, and indirect tension fatigue test. The optimum proportions of the of the mixes with highest stability are selected from the Marshall stability test. The indirect tensile strength test results show that the SMA mix replaced with RAP without rejuvenators showed higher tensile strength ratio and resistance to moisture damage when compared to conventional mix and optimum RAP replacement mix with rejuvenators. The fatigue test was conducted for the three optimum mixes at different temperature and stresses. The fatigue test results showed that at lower temperature and stresses, the RAP replaced SMA without rejuvenator offered better fatigue resistance than those with rejuvenator and conventional SMA mix. At higher temperatures, the RAP replaced SMA mix with rejuvenator offered similar fatigue lifecycle as conventional mix. However, at high stresses, conventional SMA mix offered better fatigue lifecycle. Increase in failure stresses resulted in decrease of number of fatigue cycles and increased in initial tensile strain of the mix. Thus, with the use of RAP substantial decrease in cost can be achieved without compromising the fatigue characteristic of the SMA mix.

scholarly journals Improving the Moisture Sensitivity of Asphalt Mixtures by Simultaneous Modification of Asphalt Binder and Aggregates with Carbon Nanofiber and Carbon Nanotube

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Mohammad Nikookar ◽  
Mojtaba Bagheri Movahhed ◽  
Jalal Ayoubinejad ◽  
Vahid Najafi Moghaddam Gilani ◽  
Seyed Mohsen Hosseinian
Keyword(s):  
Tensile Strength ◽  
Free Energy ◽  
Carbon Nanotube ◽  
Carbon Nanofiber ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Moisture Sensitivity ◽  
Tensile Strength Test ◽  
Indirect Tensile

Moisture sensitivity of asphalt mixtures may cause damage due to cohesion in asphalt binder membrane and adhesion between aggregate and asphalt binder that result in considerable damage to the pavements. Therefore, by determining the adhesion quality in a modified aggregate-asphalt binder system, one can choose the suitable material compositions to decrease the moisture sensitivity of mixtures. In this study, the effects of modified asphalt binder with carbon nanofiber and modified aggregates with carbon nanotube on the moisture sensitivity of asphalt mixtures were simultaneously explored. For investigating the moisture sensitivity, the indirect tensile strength test and surface free energy concept were implemented. The results of the indirect tensile strength test revealed that modification of asphalt binder and aggregates with carbon nanofiber and carbon nanotube, respectively, increased the indirect tensile strength and tensile strength ratio values of mixtures. The results of surface free energy indicated that using carbon nanofiber and carbon nanotube enhanced the adhesion free energy of the aggregate-asphalt binder system. Moreover, utilizing carbon nanofiber to modify asphalt binder enhanced the cohesion free energy values in the asphalt binder membrane. Also, carbon nanofiber and carbon nanotube brought detachment energy of the system toward zero, indicating less desire for the mixtures to be stripped. Generally, investigations performed by the two methods showed that covering aggregates by carbon nanotube as well as utilizing carbon nanofiber as an asphalt binder modifier had a positive impact on decreasing moisture sensitivity of asphalt mixtures.

scholarly journals Rejuvenation Mechanism of Asphalt Mixtures Modified with Crumb Rubber

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 370-384
Author(s):  
Hossein Noorvand ◽  
Kamil Kaloush ◽  
Jose Medina ◽  
Shane Underwood
Keyword(s):  
Tensile Strength ◽  
Dynamic Loading ◽  
Creep Compliance ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Strength Testing ◽  
Noise Mitigation ◽  
Indirect Tensile

Asphalt aging is one of the main factors causing asphalt pavements deterioration. Previous studies reported on some aging benefits of asphalt rubber mixtures through laboratory evaluation. A field observation of various pavement sections of crumb rubber modified asphalt friction courses (ARFC) in the Phoenix, Arizona area indicated an interesting pattern of transverse/reflective cracking. These ARFC courses were placed several years ago on existing jointed plain concrete pavements for highway noise mitigation. Over the years, the shoulders had very noticeable and extensive cracking over the joints; however, the driving lanes of the pavement showed less cracking formation in severity and extent. The issue with this phenomenon is that widely adopted theories that stem from continuum mechanics of materials and layered mechanics of pavement systems cannot directly explain this phenomenon. One hypothesis could be that traffic loads continually manipulate the pavement over time, which causes some maltenes (oils and resins) compounds absorbed in the crumb rubber particles to migrate out leading to rejuvenation of the mastic in the asphalt mixture. To investigate the validity of such a hypothesis, an experimental laboratory testing was undertaken to condition samples with and without dynamic loads at high temperatures. This was followed by creep compliance and indirect tensile strength testing. The results showed the higher creep for samples aged with dynamic loading compared to those aged without loading. Higher creep compliance was attributed to higher flexibility of samples due to the rejuvenation of the maltenes. This was also supported by the higher fracture energy results obtained for samples conditioned with dynamic loading from indirect tensile strength testing.

Research on Performance of Emulsion Asphalt Cold Reclaimed Mixture with Various RAP Contents

2011 ◽  
Vol 255-260 ◽  
pp. 3432-3436
Author(s):  
Xian Yuan Tang ◽  
Jie Xiao
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Compression Test ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Beam Test ◽  
Reclaimed Asphalt ◽  
Indirect Tensile ◽  
The Impact

This paper systematically elaborates the impact upon performance of emulsion asphalt cold reclaimed asphalt mixture by different RAP contents, through a series of testing on six cold reclaimed asphalt mixtures with various RAP contents, such as single axle compression test, 15°C indirect tensile strength (ITS) test, 40°C rutting test and -10°C low-temperature bending beam test. Testing results indicate that 15°C ITS decreases from around 0.75 MPa to 0.58 MPa with the RAP content of mixture increasing from 0% to 100%. 40°C dynamic stabilities reduce considerably from around 19,000 time/mm of 0% RAP mixture to 3,600 time/mm of 100% RAP mixture. -10°C failure strains only change from 1500με to 2000με.

Research of Mechanical Properties of Asphalt Pavement Materials with WMA and RAP

2012 ◽  
Vol 204-208 ◽  
pp. 3934-3937 ◽  
Author(s):  
Bao Yang Yu ◽  
Yu Wang ◽  
Min Jiang Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Dynamic Modulus ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Porous Asphalt ◽  
Compaction Energy ◽  
Indirect Tensile

The objectives of this paper are to characterize the mechanical properties of porous asphalt pavement mixtures containing RAP and a WMA additive using Super pave gyratory compactor and dynamic modulus testing. Four types of asphalt mixtures were evaluated in this study. This study evaluated compaction energy index, permeability, indirect tensile strength, and dynamic modulus for all types of porous asphalt mixtures. All of the asphalt mixtures meet the typical minimum coefficient of permeability in this study. In addition, only a slight decrease in was found when WMA additive was added to the porous asphalt mixture containing RAP. For indirect tensile strength testing, WMA containing RAP was found to have the highest tensile strength among all of the mixtures tested.

Effect of Modified Asphalt Cement of the Performance of Stone Matrix Mixtures

2020 ◽  
Vol 38 (5A) ◽  
pp. 789-800
Author(s):  
Duaa A. Khalaf ◽  
Zaynab I. Qasim ◽  
Karim H. Al Helo
Keyword(s):  
Tensile Strength ◽  
Fracture Resistance ◽  
Laboratory Tests ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Asphalt Cement ◽  
Indirect Tensile ◽  
Marshall Stability ◽  
Stone Matrix

This research investigates the behavior of Stone Matrix Asphalt mixtures (SMA) modified with styrene-butadiene-styrene (SBS) polymer at four percentages (1, 2, 3 and 4%) by weight of asphalt cement. The moisture susceptibility and rutting were taken into consideration in this study. To achieve the objective of this research the superpave system is conducted to design the asphalt mixtures. The physical properties of aggregate, bitumen and other mix materials were assessed and evaluated with the laboratory tests. The mixtures were prepared using penetration Graded (40-50) bitumen and a chemical named Polypropylene Fibers was used as a stabilizing additive. Fibers have been used in SMA mixtures for two main reasons: To increase the toughness and fracture resistance of hot mix asphalt (HMA) and to act as a stabilizer to prevent drain down of the asphalt binder. The laboratory tests include indirect tensile strength test, Marshall stability and retained Marshall Stability test (RMS). For rutting test the Roller wheel compactor is used for preparing the asphaltic samples and Wheel tracking device is used to evaluate the rutting of asphaltic slabs. The results showed that the SBS polymer asphalt mixture gave better moisture sensitivity and better fracture resistance according to the study.It is noted that indirect tensile strength ratio (TSR) increases by 93.1 % and the rut depth decreases by 32.5 % when adding 3% SBS polymer to SMA.

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