Study on long-term water stability of ATB-25 reclaimed asphalt mixture

2021 ◽  
Author(s):  
Zhennan Ma
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sun Min ◽  
Yufeng Bi ◽  
Mulian Zheng ◽  
Sai Chen ◽  
Jingjing Li

The energy consumption and greenhouse gas emission of asphalt pavement have become a very serious global problem. The high-temperature stability and durability of polyurethane (PU) are very good. It is studied as an alternative binder for asphalt recently. However, the strength-forming mechanism and the mixture structure of the PU mixture are different from the asphalt mixture. This work explored the design and performance evaluation of the PU mixture. The PU content of mixtures was determined by the creep slope (K), tensile strength ratios (TSR), immersion Cantabro loss (ICL), and the volume of air voids (VV) to ensure better water stability. The high- and low-temperature stability, water stability, dynamic mechanical property, and sustainability of the PU mixture were evaluated and compared with those of the stone matrix asphalt mixture (SMA). The test results showed that the dynamic stability and bending strain of the PU mixture were about 7.5 and 2.3 times of SMA. The adhesion level of PU and the basalt aggregate was one level greater than the limestone, and basalt aggregates were proposed to use in the PU mixture to improve water stability. Although the initial TSR and ICL of PU mixture were lower, the long-term values were higher; the PUM had better long-term water damage resistance. The dynamic modulus and phase angles (φ) of the PU mixture were much higher. The energy consumption and CO2 emission of the PU mixture were lower than those of SMA. Therefore, the cold-mixed PU mixture is a sustainable material with excellent performance and can be used as a substitute for asphalt mixture.


2013 ◽  
Vol 639-640 ◽  
pp. 346-349
Author(s):  
Zhao Bin Xie

In order to verify the characterization degree of water stability, research selects some clay content aggregate retrieved from road engineering field to produce rubber asphalt mixture and carry out the water stability test. Test results show that clay content in aggregate has a significant influence on the water stability of rubber asphalt mixture. When the content of clay in aggregate less than 1%, the influence on water stability is smaller; when the clay content exceeds 2%, the decay rate on water stability performance and long term properties obviously speed up, resulted in serious water damage.


Author(s):  
Jinrong Wu ◽  
Zhaoxu Niu ◽  
Haiyan Chen

Abstract In order to study the influence of different aging conditions on the low-temperature crack resistance and water stability of polyester fiber asphalt mixture. Prepare standard Marshall specimens of asphalt mixture with 0.4 % polyester fiber doping, and carry out water immersion Marshall test and low temperature splitting test through indoor asphalt mortar aging, asphalt mixture short-term aging and long-term aging. The results show that: under the three aging conditions, when the water immersion and low temperature time are fixed, with the increase of the aging degree, the water stability and low temperature crack resistance of the asphalt mixture decrease. When the immersion time is 2 h, the stability of asphalt mortar aging and short-term aging decreases by 6.0% and 11.8%, respectively, compared with unaging, but the long-term aging is only 3.6% lower than the short-term aging. When the temperature is -5℃, the split tensile strength of asphalt mortar aged and short-term aged increases by 4.24% and 14.35%, respectively, compared with unaging, while long-term aging only increases 4.18% compared with short-term aging. This indicates that the short-term aging condition has the most significant effect on the water stability and low-temperature crack resistance of polyester fiber asphalt mixes. At the same time, this study established a regression equation between the test temperature and the low temperature evaluation index through quadratic fitting (the correlation coefficient is 0.960-0.998), and the regression relationship can be used to estimate the low temperature evaluation index at different test temperatures.


2021 ◽  
Vol 11 (11) ◽  
pp. 5145
Author(s):  
Bangwei Wu ◽  
Xing Wu ◽  
Peng Xiao ◽  
Chuangchuang Chen ◽  
Ji Xia ◽  
...  

To clarify the influence of fiber type on the long-term performance of stone mastic asphalt (SMA), this paper used basalt fiber (BF) and lignin fiber (LF) to modify SMA-13 (SMA with aggregate nominal maximum particle size of 13.2 mm) asphalt mixture. The pavement performances (high-temperature performance, cracking resistance at low and medium temperature, and water stability) of the two kinds of fiber-reinforced SMA-13 were checked under different aging degrees (unaged, short-term aged and long-term aged), scanning electron microscope (SEM) test was conducted to explain the strengthening mechanism of the fibers. Fourier transform infrared spectrometry (FTIR) was used to analyze the changes in the chemical composition of asphalt after aging. The results of the wheel tracking test and uniaxial penetration test showed that the high-temperature performance of the BFSMA-13 (defined as the SMA-13 containing BF) is better than that of the LFSMA-13 (defined as the SMA-13 containing LF) at different aging degrees. The high-temperature performance of BFSMA-13 increases with the increase of the aging degree, while the aging process decreases the high-temperature property of LFSMA-13. The results of the three-point bending test and semi-circular bending (SCB) proved that BFSMA-13 is more capable of deformation and less prone to cracking at low and medium temperatures. The results of the immersion Marshal test indicated that BF can better improve the strength and the water stability of the SMA-13 mixture than LF. The SEM images showed that basalt fibers form a solid three-dimensional network structure in the mixture which could contribute to the strengthening of the mixture. The results of infrared spectroscopy analysis showed that styrene–butadiene–styrene (SBS) degrades during asphalt mixture aging, and that the chemical composition of asphalt changes more after aging in LFSMA-13 than in BFSMA-13. The conclusions of this study help toward further understanding of the performance changes of the SMA-13 mixture during its service life and to guide the selection of fiber additives for SMA-13 mixtures.


2021 ◽  
Vol 261 ◽  
pp. 02058
Author(s):  
Zheng Zhigang ◽  
He Yunwu ◽  
Wang Tao ◽  
Wei Hanxin ◽  
Liang Xiayi ◽  
...  

In order to evaluate the performance of the physical foaming warm-mix recycled asphalt mixture (WRAM), the hot mix plant recycling technology was adopted to develop AC-20 hot-mix recycled asphalt mixture (HRAM) and the WRAM of different reclaimed asphalt pavement (RAP) contents. The high temperature stability, water stability and low temperature crack resistance performance of the reclaimed asphalt pavement were evaluated. The results indicate that the physical foaming WRAM feature better high temperature stability, water stability and low temperature crack resistance compared to those of HRAM. With the increase in RAP contents, the high temperature stability of the physical foaming WRAM and HRAM rises notably but the water stability and low temperature crack resistance performance continues to drop.


2013 ◽  
Vol 753-755 ◽  
pp. 819-822
Author(s):  
Kui Li ◽  
De Dong Guo

AC-13C asphalt mixtures were mixing with 3% Evotherm® content and the optimal compaction temperature was determined according to test results of specimens formed at 4 different compaction temperatures by Marshall method. The general water stability tests and Hamburg wheel-tracking device (HWTD) were used to test the water stability of 4 kinds of asphalt mixtures, which were ordinary asphalt mixture, Evotherm® asphalt mixture without adding any anti-stripping agent, Evotherm® asphalt mixture adding liquid anti-stripping agent and Evotherm® asphalt mixture adding hydrated lime. Test results shows that the optimal compaction temperature is about 125°C; and compared to ordinary asphalt mixture, the long-term water stability of Evotherm® asphalt mixture is obviously poor caused by the lower compaction temperature; the addition of either liquid anti-stripping agent or hydrated lime improve the water stability to a great extent; comparatively speaking, addition of hydrated lime is the optimum measure to improve the water stability of Evotherm® warm mixture asphalt.


Author(s):  
Behnam Jahangiri ◽  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
William G. Buttlar

Various agencies have begun to research and introduce performance-related specifications (PRS) for the design of modern asphalt paving mixtures. The focus of most recent studies has been directed toward simplified cracking test development and evaluation. In some cases, development and validation of PRS has been performed, building on these new tests, often by comparison of test values to accelerated pavement test studies and/or to limited field data. This study describes the findings of a comprehensive research project conducted at Illinois Tollway, leading to a PRS for the design of mainline and shoulder asphalt mixtures. A novel approach was developed, involving the systematic establishment of specification requirements based on: 1) selection of baseline values based on minimally acceptable field performance thresholds; 2) elevation of thresholds to account for differences between short-term lab aging and expected long-term field aging; 3) further elevation of thresholds to account for variability in lab testing, plus variability in the testing of field cores; and 4) final adjustment and rounding of thresholds based on a consensus process. After a thorough evaluation of different candidate cracking tests in the course of the project, the Disk-shaped Compact Tension—DC(T)—test was chosen to be retained in the Illinois Tollway PRS and to be presented in this study for the design of crack-resistant mixtures. The DC(T) test was selected because of its high degree of correlation with field results and its excellent repeatability. Tailored Hamburg rut depth and stripping inflection point thresholds were also established for mainline and shoulder mixes.


Author(s):  
Amir Golalipour ◽  
Varun Veginati ◽  
David J. Mensching

In the asphalt materials community, the most critical research need is centered around a paradigm shift in mixture design from the volumetric process of the previous 20-plus years to an optimization procedure based on laboratory-measured mechanical properties that should lead to an increase in long-term pavement performance. This study is focused on advancing the state of understanding with respect to the value of intermediate temperature cracking tests, which may be included in a balanced mix design. The materials included are plant-mixed, laboratory-compacted specimens reheated from the 2013 Federal Highway Administration’s (FHWA’s) Accelerated Loading Facility (ALF) study on reclaimed asphalt pavement/reclaimed asphalt shingle (RAP/RAS) materials. Six commonly discussed intermediate temperature (cracking and durability) performance testing (i.e., Asphalt Mixture Performance Tester [AMPT] Cyclic Fatigue, Cantabro, Illinois Flexibility Index Test [I-FIT], Indirect Tensile Cracking [ITC, also known as IDEAL-CT], Indirect Tensile Nflex, and Texas Overlay Test) were selected for use in this study based on input from stakeholders. Test results were analyzed to compare differences between the cracking tests. In addition, statistical analyses were conducted to assess the separation among materials (lanes) for each performance test. Cyclic fatigue and IDEAL-CT tests showed the most promising results. The ranking from these two tests’ index parameters matched closely with ALF field performance. Furthermore, both showed reasonable variability of test data and they were successful in differentiating between different materials.


Sign in / Sign up

Export Citation Format

Share Document