Laboratory Study on the Effect of Asphalt Emulsion as a Rejuvenator in Aged Asphalt Pavement

2012 ◽  
Vol 587 ◽  
pp. 57-61
Author(s):  
Rashid Tanzadeh ◽  
Mahyar Arabani

Modification of the asphalt binder is one approach taken to improve aged pavement performance. To make the most of maintenance budgets, many agencies have resorted to the use of asphalt rejuvenators as an alternative to revive aging and brittle asphalt pavements. The purpose of this study is laboratory research on the effect of asphalt emulsion in restoring the original properties of aged asphalt pavement. For this purpose, the repeated load axial test is carried out on conventional asphalt samples and aged asphalt samples containing rejuvenator agents in different stress and rejuvenator percentage. Bitumen aged with RTFO according to ASTM-D2872 and the optimum bitumen of 5.5% were considered. The softening point and penetration tests, to examine the effect of rejuvenator in asphalt mixtures modification, On the basic, aged and modified aged bitumen were performed. The results represent that asphalt emulsion as a rejuvenator material in aged asphalt samples because of suitable performance improve aged asphalt permanent deformation resistance and aged bitumen Rheological property.

2016 ◽  
Vol 43 (5) ◽  
pp. 472-479 ◽  
Author(s):  
João Victor Staub de Melo ◽  
Glicério Trichês

Rutting is one of the most important issues associated with asphalt pavements. This defect leads to the accelerated degradation of the pavement and considerably reduces the level of road safety. This paper reports on the results obtained in the optimization of nanocomposite asphalt containing carbon nanotubes (CNTs) with regard to the resistance to permanent deformation. Nanocomposite asphalts were prepared with the addition of different proportions of CNTs. Based on a study on the empirical and rheological properties of the nanocomposites developed, optimization of the CNT content incorporated into the conventional asphalt binder was carried out. Then two asphalt mixtures were investigated, a reference mixture and a nanomodified mixture with CNTs (optimal content). The rheological evaluations were carried out on four-point fatigue equipment and the resistance to permanent deformation was tested in a traffic simulator (wheel tracking test). The results demonstrate the efficient contribution of the nanocomposite to the resistance to permanent deformation.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2036
Author(s):  
Dongzhao Jin ◽  
Dongdong Ge ◽  
Siyu Chen ◽  
Tiankai Che ◽  
Hongfu Liu ◽  
...  

Cold in-place recycling (CIR) asphalt mixtures are an attractive eco-friendly method for rehabilitating asphalt pavement. However, the on-site CIR asphalt mixture generally has a high air void because of the moisture content during construction, and the moisture susceptibility is vital for estimating the road service life. Therefore, the main purpose of this research is to characterize the effect of moisture on the high-temperature and low-temperature performance of a CIR asphalt mixture to predict CIR pavement distress based on a mechanistic–empirical (M-E) pavement design. Moisture conditioning was simulated by the moisture-induced stress tester (MIST). The moisture susceptibility performance of the CIR asphalt mixture (pre-mist and post-mist) was estimated by a dynamic modulus test and a disk-shaped compact tension (DCT) test. In addition, the standard solvent extraction test was used to obtain the reclaimed asphalt pavement (RAP) and CIR asphalt. Asphalt binder performance, including higher temperature and medium temperature performance, was evaluated by dynamic shear rheometer (DSR) equipment and low-temperature properties were estimated by the asphalt binder cracking device (ABCD). Then the predicted pavement distresses were estimated based on the pavement M-E design method. The experimental results revealed that (1) DCT and dynamic modulus tests are sensitive to moisture conditioning. The dynamic modulus decreased by 13% to 43% at various temperatures and frequencies, and the low-temperature cracking energy decreased by 20%. (2) RAP asphalt incorporated with asphalt emulsion decreased the high-temperature rutting resistance but improved the low-temperature anti-cracking and the fatigue life. The M-E design results showed that the RAP incorporated with asphalt emulsion reduced the international roughness index (IRI) and AC bottom-up fatigue predictions, while increasing the total rutting and AC rutting predictions. The moisture damage in the CIR pavement layer also did not significantly affect the predicted distress with low traffic volume. In summary, the implementation of CIR technology in the project improved low-temperature cracking and fatigue performance in the asphalt pavement. Meanwhile, the moisture damage of the CIR asphalt mixture accelerated high-temperature rutting and low-temperature cracking, but it may be acceptable when used for low-volume roads.


2012 ◽  
Vol 622-623 ◽  
pp. 990-994 ◽  
Author(s):  
Javad Tanzadeh ◽  
Fariborz Vahedi ◽  
Pezhouhan T. Kheiry ◽  
Rashid Tanzadeh

Modification of the asphalt binder is one approach taken to improve Asphalt pavement performance. Rutting is one of the most important factors that could reduce the life of asphalt pavements.Nowadays, the application of nanotechnologyto achieve materials that are more resistant is expanding in asphalt pavement thatNano-TiO2is among the most exciting and promising classes of materials discovered recently. The purpose of this study is laboratory research on the effect of Nano-TiO2in improving Bitumen property and rutting resistance in Asphalt pavement under dynamic loading. For this purpose, the wheel-tracking test was carried outon ordinary and Nano-TiO2modified hot mix asphalt samples.The results illustrate that using Nano-TiO2in asphaltbinder samples cause to an improvement in ruttingdepth in comparison with theordinarymixtures.


2021 ◽  
Vol 1023 ◽  
pp. 121-126
Author(s):  
Van Bach Le ◽  
Van Phuc Le

Although small amount of binder in asphalt concrete mixture may commonly range from 3.5 to 5.5% of total mixture as per many international specifications, it has a significant impact on the total cost of pavement construction. Therefore, this paper investigated the effects of five carbon nanotubes contents of 0.05%, 0.1%, 0.15%, 0.2%, 0.25% by asphalt weight as an additive material for binder on performance characteristics of asphalt mixtures. Performance properties of CNTs modified asphalt mixtures were investigated through the Marshall stability (MS) test, indirect tensile (IDT) test, static modulus (SM) test, wheel tracking (WT) test. The results indicated that asphalt mixtures with CNT modified binder can improve both the rutting performance, IDT strength and marshall stability of tested asphalt mixtures significantly at higher percentages of carbon nanotubes. However, the issue that should be considered is the construction cost of asphalt pavement. Based on the asphalt pavement structural analysis and construction cost, it can be concluded that an optimum CNT content of 0.1% by asphalt weight may be used as additive for asphalt binder in asphalt mixtures.


Author(s):  
Intikhab Haidar ◽  
Charles W. Schwartz ◽  
Sadaf Khosravifar

The past two decades have seen significant efforts to standardize a series of simplified test methods to characterize the dynamic modulus (DM) and repeated load permanent deformation (RLPD) performance characteristics of asphalt mixtures using the asphalt mixtures performance tester (AMPT). While the current AASHTO T 79 test specifications for the AMPT are faster and easier to perform than their preceding research grade test protocols, there is still reluctance among highway agencies and industry to conduct performance testing using the AMPT. One significant reason is the lengthy process of sample preparation and testing for the DM and RLPD tests. Two studies to expedite this process are reported here. First, the potential for abbreviating the DM testing procedure was examined. It provides the option to fully exclude testing at 40°C by adding an additional frequency of 0.01 Hz at 20°C. This approach reduces time for testing as well as for sample conditioning at high temperature. Second, the possibility of reducing the total number of required specimens was evaluated. The variation of the DM under repetitive testing and the appropriateness of performing the RLPD test on samples already tested for DM were evaluated. The results showed that specimen damage or densification because of DM testing is insignificant. As a consequence, DM test specimens can be re-used for RLPD testing, reducing the required number of samples from 12 to 9.


Author(s):  
Gerald A. Huber ◽  
Xishun Zhang ◽  
Robin Fontaine

The Strategic Highway Research Program (SHRP) spent $50 million researching asphalt binders and asphalt mixtures and provided three main products: an asphalt binder specification, an asphalt mixture specification, and Superpave, an asphalt mixture design system that encompasses both the binder and mixture specification. SHRP researchers have provided tools that promise more robust asphalt mixtures with reduced risk of premature failure. Implementation of the specifications and mix design system will require overcoming several obstacles. Superpave must be demonstrated to be practical and easy to use. The impact of Superpave aggregate requirements on aggregate availability must be determined. The Superpave gyratory compaction procedure has been uniquely defined and then calibrated to traffic volume. The reasonableness of this approach must be tested in widespread application. Perhaps the largest implementation hurdle exists in the performance models. Expensive test equipment is necessary to do the performance-based tests. The performance predictions must be established as reasonable to justify the cost. A highway reconstruction project containing three Superpave Level 1 mix designs is documented including quality control done with the Superpave gyratory compactor. Superpave Level 2 performance-based tests were carried out to predict permanent deformation of the design and the mixture as constructed. The performance-based engineering properties obtained from the tests are evaluated, and the reasonableness of the performance prediction models is discussed.


2000 ◽  
Vol 1723 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Rajesh K. Bhairampally ◽  
Robert L. Lytton ◽  
Dallas N. Little

Repeated-load permanent deformation testing has long been a popular way to characterize the performance of asphalt mixtures and to account for damage that leads to rutting. A number of empirical models have been used to fit repeated-load permanent deformation data. One such model, developed by Tseng and Lytton in 1989, fits permanent deformation data of most asphalt mixtures well. However, some mixtures exhibit a rate of damage that is in excess of that predicted by the 1989 Tseng and Lytton model. A numerical adaptation of the Tseng and Lytton empirical model is presented that readily characterizes such damage-susceptible mixtures. The excessive rate of damage is explained and reconciled in terms of plastic work theory and dissipated strain energy. The numerical approach is used to demonstrate the corrective effects of two types of additives to the mixtures: a recycled coproduct and hydrated lime.


Author(s):  
Ali Zalghout ◽  
Nooralhuda Saleh ◽  
Samir Sari Ad Din ◽  
Ghassan Chehab

The incorporation of geothermal energy in heating and electricity production has rapidly increased during the last three decades. This paper focuses on the use of shallow geothermal energy in asphalt pavement, herein called Ground Coupled Hydronic Asphalt Pavement (GCHAP) system. GCHAP consists of a series of pipes embedded within the asphalt layer coupled with another network of pipes embedded in the soil. A circulating fluid acts to exchange the heat energy between the soil and the asphalt layer. The system can be used for cooling the pavement, which results in decreasing permanent deformation in the summer. This paper presents a study on the constructability and performance of such systems on a large-scale section. Numerical analyses and a pilot study were conducted to select the system design components. A 9.6 x 4 meter GCHAP section was constructed on a municipal road in addition to another control section. The secondary network of pipes was placed three meters below the ground. Sensors were embedded within the GCHAP system to record and compare the temperature of the pavement to that of the control section. The results showed that GCHAP section can decrease the pavement temperature leading to an increase in resistance to permanent deformation. Moreover, the constructability study showed the importance of performing a pilot study before constructing the system to ensure the resilience of the pipes.


2013 ◽  
Vol 723 ◽  
pp. 617-622
Author(s):  
Er Hu Yan ◽  
Fu Pu Li ◽  
Rong Ma ◽  
Fei Chen

Climate change is one of the most key global topics well-known in international community. Over the past decades years, the change climate and its impact on asphalt pavement in China is very obvious. Many expressways of asphalt pavement come forth severe rutting failure during only a few days of extensive, long-lasting, extreme heat wave in summer, which resulting in the change of asphalt cement specification and the selection practice of asphalt cement. So it is necessary to review climate change and its impact in the past, and forecast the probable situation in the future. The paper focuses specifically on the issue of asphalt binder selection under changing climatic conditions.


2017 ◽  
Vol 730 ◽  
pp. 380-388 ◽  
Author(s):  
Michal Varaus ◽  
Tomas Koudelka ◽  
Pavel Sperka

As the amount of reclaimed asphalt pavement (RAP) material used in asphalt mixtures has increased recently, it is vital to address problems regarding aged binder incorporated in RAP. Asphalt binder hardens during its production process as well as during service life of pavements. External influences such as oxygen and ultraviolet radiation affect greatly bitumen characteristics. Thanks to adding rejuvenating agents, the original binder properties should be recovered and resulting asphalt binder parameters should become equal to those measured upon the reference material. In this study, four different rejuvenator agents and one neat soft binder were employed to rejuvenate the artificially aged binder by a complete blending between both constituents. Thereafter, empirical as well as performance based binder properties were examined with a dynamic shear rheometer (DSR) and with a bending beam rheometer (BBR). Three different dosages of each rejuvenator were added to evaluate the required amount for the original binder properties to be restored. Moreover, the softening efficiency of each agent was assessed by means of the Ring and Ball test. Finally, the optimum amount of each rejuvenator needed for the blend to achieve the target specification was determined. It can be concluded that the rejuvenators affect binder properties greatly, and mainly in a positive way. However, the data also indicate significant discrepancies between the types of the rejuvenator.


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