Short-Term and Long-Term Aging Behavior of Rubber Modified Asphalt Paving Mixture

Author(s):  
Robert Y. Liang ◽  
Suckhong Lee

Aging of asphalt has been an important subject area that has received extensive studies in recent years. Test results of short-term and long-term aging behavior of crumb rubber modifier (CRM) modified asphalt paving materials are presented. Eighteen combinations of CRM modified binders in terms of CRM size, CRM content, and base asphalt cement grade were studied by Brookfield viscometer test and dynamic shear rheometer test. The short-term aged binders were prepared using thin film oven test. Viscosity was measured at 350°F in the Brookfield thermosel after mixing at 375°F for 2 hr. The test results showed that the size and percentage of CRM affected the viscosity development in the modified binders: the smaller the CRM size and the higher the CRM content, the higher the viscosity measured after 2-hr reaction at 375°F. Short-term aging exerted more viscosity increase in the CRM modified binders than in the unmodified binders. Modified binders showed less weight loss than unmodified binders. The modified binders showed higher complex modulus G* than unmodified. Short-term aging increased G*, with modified binders exhibiting higher increase. The Marshall mix design yielded various CRM modified mixes. The result of indirect tensile strength tests showed that short-term and long-term aging increased the measured tensile strengths. The resilient modulus test results, in general, supported the general understanding that aging tended to increase resilient modulus.

2007 ◽  
Vol 13 (4) ◽  
pp. 307-315 ◽  
Author(s):  
Piotr Radziszewski

Permanent deformations, primarily in the form of ruts, are one of the basic asphalt pavement damages impairing its service properties. Application of appropriate asphalt mixtures and binder modification are effective methods for improving asphalt courses resistance. While being manufactured, stored, fitted into a road pavement and during long term service, bitumen binders and asphalt mixtures are subject to continuous unfavourable ageing processes during which pavement courses characteristics change considerably, resistance to permanent deformations being among them. This article presents rut and dynamic creep test results of concrete, SMA (stone mastic asphalt), MNU (thin courses of non‐continuous grain mixtures), Superpave mixture and porous asphalt mixture of two air void content percentages: 15 %, 20 %. Asphalt concrete mixtures, MNU's and porous asphalt mixtures contained elastomer, plastomer and fine rubber modified binders. Samples for laboratory rut tests were made by slab compaction because this method, as the author's previous research had shown, was the closest to ‘in‐situ’ conditions. Resistance to permanent deformations of the examined specimens was evaluated before aging, after technological aging (short term ageing) and after service ageing (long‐term ageing). The test results show that resistance to permanent deformations depends on the kind of asphalt mixture and binder applied. Concrete asphalts with fine rubber modified bitumens and concrete asphalts with 7 % polymer modified binders as well as SMA's and Superpave mixtures with unmodified binders appeared to be most resistant to permanent deformations after a long‐term laboratory ageing. It was proved that the overall evaluation of resistance to permanent deformations could be obtained by rut and creep testing of asphalt mixtures exposed to short‐ and long‐term ageing. Simultaneous determining 4 parameters: maximum rut depth after short‐term ageing, rutting coefficient after operational ageing, stiffness creeping modulus after long‐term ageing and cumulated deformation after short‐term ageing, facilitates full characteristics of modified asphalt mixes designed to be built in the wearing course of a road pavement.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1039 ◽  
Author(s):  
Bo Li ◽  
Jianing Zhou ◽  
Zhihao Zhang ◽  
Xiaolong Yang ◽  
Yu Wu

Effective approaches are required to be developed to solve the poor compatibility and thermal stability problems of crumb rubber-modified asphalt (CRMA). This study focuses on a method called microwave activation. However, seldom researches pay attention to the properties of MACRMA after aging. The objective of this study was to prepare microwave-activated CRMA (MACRMA) and investigate the performance of asphalt after aging. The samples were subjected to thin-film oven test (TFOT) at different times and temperatures. The effect of heat aging on the properties of MACRMA was evaluated by three indicator tests: viscosity, dynamic shear rheology test (DSR), and repeat creep recovery test (RCRT). The test results indicated that the MACRMA after two aging conditions had noticeably lower performance values (e.g., penetration, ductility) compared to unaged samples, and thus, the need to control temperature and time for mixing and construction was verified to be important. In addition, the G*/sin δ and phase angle values were largely influenced by the TFOT aging temperature and time. The MACRMA’s ability to recover was improved after aging. Compared with the aging temperature, the aging time had a more significant effect on the deformation and recovery ability of MACRMA.


2016 ◽  
Vol 43 (4) ◽  
pp. 326-333 ◽  
Author(s):  
Hyun Hwan Kim ◽  
Soon-Jae Lee

Cracking properties of crumb rubber modified (CRM) asphalt binders containing wax additive were evaluated through the dynamic shear rheometer test at 25 °C and the bending beam rheometer test at −12 °C. The CRM binders were produced using three rubber contents of 5%, 10%, and 15% by the binder weight, and then mixed with two commercial wax additives of LEADCAP and Sasobit. Three states of original, short-term and long-term aging were applied to evaluate the cracking properties using rolling thin film oven and pressure aging vessel. From the results, it is concluded that (1) the increase of rubber content significantly decreases the binder stiffness at lower temperature, (2) the higher the rubber content, the lower the G*sinδ of CRM binders with wax additives at intermediate temperature, and (3) the rubber can be used to improve the cracking resistance of asphalt binders modified with wax.


Author(s):  
Zhurinov M.Zh., ◽  
◽  
Teltayev B.B., ◽  
Kalybay A.A., ◽  
Rossi C.O., ◽  
...  

A comparative analysis of the low temperature resistance for a nanocarbon bitumen and other 30 neat and modified bitumens has been performed in the work. The stiffness at the temperatures of -24°С, -30°С and -36°С under technical system Superpave has been accepted as an indicator of low temperature resistance of the bitumens. The stiffness of the bitumens has been determined on a bending beam rheometer (standard ASTM D 6648-08). Before testing the bitumens have been subjected to the double artificial aging: short-term aging – under standard AASHTO Т 240-13 and long-term aging – under standard ASTM D 6521-08. The nanocarbon bitumen has been prepared in the laboratory of the Kazakhstan Highway Research Institute (KazdorNII) with the use of a road bitumen of the grade BND 70/100 produced by the Pavlodar petrochemical plant (PNHZ) and a nanocarbon powder (2% by weight) manufactured from a coal rock of the deposit “Saryadyr” “Corporation “ON-Olzha” LLP, Akmola region, Kazakhstan). The nanocarbon powder (150-200 nm) has been manufactured by three-stage size reduction of the coal rock: I – a mechanical dispergator (up to 2-3 mm), II – an aerodynamic mill (up to 20 mcm), III – a reactor with a rotating electromagnetic field. The neat bitumens of the grades BND 50/70, BND 70/100, BND 100/130 have been produced by the plants of Kazakhstan and Russia; they satisfy the requirements of the standard ST RK 1373-2013. The modified bitumens have been prepared in the laboratory of KazdorNII with the use of the neat bitumens, 7 types of the polymers, crumb rubber and polyphosphoric acid and they satisfy the requirements of the standard ST RK 2534-2014. It has been determined that the nanocarbon bitumen is one of the most resistant at the low temperatures: -24°С, -30°С and -36°С.


1994 ◽  
Vol 21 (6) ◽  
pp. 954-965 ◽  
Author(s):  
N. Ali ◽  
Shaher Zahran ◽  
Jim Trogdon ◽  
Art Bergan

The main purpose of this study was to facilitate decisions concerning the effectiveness of modifiers in mitigating pavement distress and improving long-term overall pavement performance in actual field conditions, by utilizing short-term laboratory results and a mathematical prediction model. The modifiers investigated were carbon black, neoprene latex, and polymer modified asphalt (STYRELF). The statistical general linear model (GLM) and the Fisher least significant difference (LSD) were used for the analysis of data. The results of the study indicate that the effect of the modifier on the paving mixture properties was insignificant at low temperatures (down to −17 °C), but significant at high temperatures (up to 60 °C) where the synergistic effect of the modifier on the paving mixture was pronounced. The VESYS IIIA pavement performance prediction model was utilized to assess the effects, if any, of the modifier on the pavement's overall performance. All the modifiers improve, to some degree, the overall pavement performance. Key words: modifiers, asphalt, paving mixtures, pavements, polymer asphalt.


2019 ◽  
Vol 234 ◽  
pp. 1262-1274 ◽  
Author(s):  
Zixuan Chen ◽  
Tao Wang ◽  
Jianzhong Pei ◽  
Serji Amirkhanian ◽  
Feipeng Xiao ◽  
...  

2020 ◽  
Vol 261 ◽  
pp. 119682 ◽  
Author(s):  
Yunhao Wei ◽  
Yu Liu ◽  
Yaseen Muhammad ◽  
Sidra Subhan ◽  
Fei Meng ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2345 ◽  
Author(s):  
Yangsheng Ye ◽  
Gang Xu ◽  
Liangwei Lou ◽  
Xianhua Chen ◽  
Degou Cai ◽  
...  

In this study, a new type of composite modified bitumen was developed by blending styrene-butadiene-styrene (SBS) and crumb rubber (CR) with a chemical method to satisfy the durability requirements of waterproofing material in the waterproofing layer of high-speed railway subgrade. A pressure-aging-vessel test for 20, 40 and 80 h were conducted to obtain bitumen samples in different long-term aging conditions. Multiple stress creep recovery (MSCR) tests, linear amplitude scanning tests and bending beam rheometer tests were conducted on three kinds of asphalt binders (SBS modified asphalt, CR modified asphalt and SBS/CR composite modified asphalt) after different long-term aging processes, including high temperature permanent deformation performance, resistance to low temperature thermal and fatigue crack. Meanwhile, aging sensitivities were compared by different rheological indices. Results showed that SBS/CR composite modified asphalt possessed the best properties before and after aging. The elastic property of CR in SBS/CR composite modified asphalt improved the ability to resist low temperature thermal and fatigue cracks at a range of low and middle temperatures. Simultaneously, the copolymer network of SBS and CR significantly improved the elastic response of the asphalt SBS/CR modified asphalt at a range of high temperatures. Furthermore, all test results indicated that the SBS/CR modified asphalt possesses the outstanding ability to anti-aging. SBS/CR is an ideal kind of asphalt to satisfy the demand of 60 years of service life in the subgrade of high speed railway.


2012 ◽  
Vol 486 ◽  
pp. 378-383 ◽  
Author(s):  
Che Wan Che Norazman ◽  
Ramadhansyah Putra Jaya ◽  
Meor Othman Hamzah

Oven ageing is a set of procedure to simulate the accelerated effects of ageing on pavements structures. In this study, the effect of long-term oven ageing on porous asphalt mixture made with SBS modified binder was investigated. The resilient modulus, water permeability and air voids test results were the performance indicators used to evaluate the effects of ageing. The test results showed that, the resilient modulus of long term aged specimens was higher than those of unaged specimens. From the permeability test results, unaged SBS mixes exhibit lower coefficient permeability compared to the corresponding long-term oven age specimens. Most likely, ageing caused binder hardening, making the mix more difficult to compact and hence exhibited more continuous voids which in turn lead to higher permeability. In addition, the coefficient of permeability decreases as the binder content increased.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Xin Yu ◽  
Ying Wang ◽  
Yilin Luo ◽  
Long Yin

Limited studies in recent years have shown that asphalt pavement subject to seawater in coastal regions or deicing salt in cold regions may be seriously damaged after being soaked in saline water for a long time. However, there is limited research into the influence of salt on rheological properties of asphalt after long-term aging. In this study, rheological properties of unmodified and polymer-modified asphalt after long-term aging were tested after being soaked in different concentrations of salt (0.3%~5%) for different durations (1 day~30 days). Orthogonal array based on the Taguchi method was used for experimental design. The frequency sweep tests were performed on the specimens of aged asphalt after being soaked for complex modulus and phase angle master curves and ultimate fatigue temperature. BBR tests were performed for stiffness. The test results indicate that saline water appears to reduce low temperature properties and fatigue resistance properties and improved high temperature properties of aged asphalt, and it also affects the sensitivity of complex modulus and phase angles at low frequencies.


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