scholarly journals Study on dynamic modulus of asphalt mixture in cold regionunder rotary accelerated loading

2021 ◽  
Vol 248 ◽  
pp. 01038
Author(s):  
Li Zhu ◽  
Jin Li ◽  
Miaozhang Yu ◽  
Di Dong ◽  
Xinzhuang Cui

In order to study the evolution law of mechanical properties of asphalt pavement mixture in cold regions under long-term load, the rotary accelerated loading equipment was used to carry out a total of 500,000 accelerated loading tests on the full-scale pavement, and the dynamic modulus test of the mixture before and after wheel load was carried out respectively. The master curve of dynamic modulus and dynamic modulus ratio (dynamic modulus value after wheel load / dynamic modulus value before wheel load) of the mixture at -20ºC were established to predict the long-term mechanical response of the mixture at low temperature. The results show that: low-frequency (or high temperature) has a more significant effect on the viscoelastic properties of the asphalt mixture. In the conversion frequency range of 1.6×10–3~1.6×102 Hz, the dynamic modulus ratio decreases with the increase of frequency, and the maximum ratio is 0.62 when the frequency is 1.6×10–3 Hz, which indicates that the high frequency (low temperature) has little effect on the performance of asphalt mixture. This study can be used as a theoretical reference for the structural design and performance optimization of asphalt pavement in cold regions.

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.


2013 ◽  
Vol 361-363 ◽  
pp. 1681-1688 ◽  
Author(s):  
Hai Sheng Zhao ◽  
Wei Chen ◽  
Xiao Yan Wang

This paper used one kind of organic additive LEADCAP to reduce the compacting temperature of SBS WMA mixture, and compared the WMA mixture compacted by superpave gyratory compactor (SGC) with HMA mixture to determine the compacting temperature of WMA mixture. Rutting test, low temperature bending test, freeze-thaw indirect tension test, Hamburg Wheel-Track test and dynamic modulus were carried out to evaluate the road performance of WMA mixed with LEASCAP. The test result showed that the WMA mixed with LEADCAP had well performed high temperature stability, low temperature stability, water stability, rutting cracking resistance, and high dynamic modulus, the compacting temperature were 127 °C, and affectively reduced the compacting temperature of SBS WMA mixture.


2014 ◽  
Vol 638-640 ◽  
pp. 1166-1170 ◽  
Author(s):  
Meng Hui Hao ◽  
Pei Wen Hao

Natural mineral fiber with good performances of mechanical properties and environmentally friendly, pollution-free especially have gradually aroused extensive concern. In order to improve the quality of asphalt pavement, explore the applicability of nature basalt fiber in enhanced asphalt mixture performance, this paper investigates two typical asphalt mixtures and contrastive studies pavement performance of asphalt mixture by high temperature stability, water stability, low temperature anti-cracking and fatigue performance between basalt fiber modified asphalt mixture and base asphalt mixture, and then study the basic principle of fiber reinforcing asphalt mixture. The research show that basalt fiber modified asphalt mixture has a better pavement performance than base asphalt mixture, its dynamic stability is 1.6 times than base asphalt mixture, low temperature anti-cracking performance increased by more 25% and fatigue life is more 2 times than base asphalt mixture. And the basalt fiber can be used in the road engineering as an additive material that enhances the comprehensive performance of asphalt pavement.


2012 ◽  
Vol 178-181 ◽  
pp. 1615-1618 ◽  
Author(s):  
Ya Li Ye ◽  
Chuan Yi Zhuang ◽  
Ren Feng Zhang

HMA dynamic modulus is one of key inputs to the Mechanistic-Empirical Pavement Design Guide. In order to analyze and evaluate bearing capacity of asphalt concrete pavement and to determinate the rules of pavement deterioration of modulus of asphalt layer under repeated wheel load and ambient, temperature correction for HMA is applied to the modulus so as to compare them with the same temperature. In order to get temperature correction coefficients for HMS moduli, a method of temperature correction for HMA moduli was put forward. In this method, the specimen of asphalt mixture or HMA cores from in-situ pavements were tested by Superpave Simple Performance Tester(SPT), or falling weight deflection(FWD) was tested on the site of in-situ pavements. The correlation between HMA dynamic modulus and temperature was regressed, and then dynamic modulus regression model was put forward. Results show that exponential function was fitted to the data to determine and adjust the modulus to a reference temperature, the recommendation regression equation can reflect the features of asphalt mixture at the reference temperature.


2013 ◽  
Vol 361-363 ◽  
pp. 1625-1628
Author(s):  
Zhao Sheng Li ◽  
Yi Qiu Tan

Establish the mechanical model of asphalt pavement low-temperature cracking, analysis the factors leading to cracking. The factors such as shrinkage coefficient of asphalt pavementtemperature stresspavement structure combination forms and temperature contribution affect the asphalt pavement on cracking behavior. Study the effect of aggregate gradation type on asphalt mixture temperature shrinkage coefficient, analyze shows that in case of the same skeleton type, the smaller the average particle size of aggregate is, the larger low-temperature shrinkage deformation of mixture is; increasing the amount of coarse aggregate can form the dense structure of skeletonreduce the shrinkage coefficient at low temperature and improve the low-temperature crack resistance ability of asphalt mixture.


2013 ◽  
Vol 779-780 ◽  
pp. 510-515 ◽  
Author(s):  
Bao Hua Shi ◽  
Ya Men Zhang ◽  
Tao Sun ◽  
Yong Jie Wang

According to requirement of operation safety and comfort of airplane on the asphalt pavement of airport, the cause incurring unevenness is discussed subject to aspects of inherent unevenness of pavement, unsatisfied construction equipment and process, repeated action of airplane load during utilization process, and long term action of natural factors, etc; aiming at the requirement on how to improve the airport construction quality and guarantee asphalt pavement roughness, and on the basis of engineering examples of bad roughness of asphalt runway, the roughness impact factors are discussed by three aspects as uneven settling of earth foundation, unstable base course, relaxed construction control of topping asphalt mixture, etc , so as to take control measures with pertinence at each stage of airport construction, to guarantee the excellent roughness of asphalt pavement.


Author(s):  
David J. Mensching ◽  
Adrian Andriescu ◽  
Christopher DeCarlo ◽  
Xinjun Li ◽  
Jack S. Youtcheff

The use of re-refined engine oil bottoms (REOBs) in asphalt pavements is a topic of much debate because the aging susceptibility and quantity of the additive in the binder may affect field performance. In this study, four mixtures with varying REOB contents (up to 15%) were long-term oven aged by using a high-temperature, short-duration method (135°C, 24 h) and compared with existing data on mixtures aged with more conventional short-term and long-term oven-aging procedures. The recovered binders underwent Superpave® grading, double-edge notched tension, and extended bending beam rheometer testing, and the binders were subjected to dynamic modulus, cyclic fatigue testing in the asphalt mixture performance tester, and thermal stress restrained specimen testing. Results showed a general insensitivity when short-term oven-aged (135°C, 4 h) materials were compared with long-term oven-aged (85°C, 5 days) materials, whereas the aging process at 135°C over 24 h resulted in substantial changes to the stiffness and relaxation properties across high-, intermediate-, and low-temperature modes. The difference between the stiffness-based and slope-based low-temperature performance grades appears to be an indicator for REOB modification, with the test for physical hardening of the binder being more sensitive than standard bending beam rheometer testing. The details in this paper provide information for the asphalt pavement community to consider as specifications. Standard practices are developed to address REOB modification.


2014 ◽  
Vol 599 ◽  
pp. 282-286 ◽  
Author(s):  
Chun Gang Zhang ◽  
Yan Jun Xie ◽  
Lin Chun Meng ◽  
Qin Yong Li

This paper investigated into the application of fiber-enhanced asphalt mixture in surface layer of the large longitudinal slope pavement of Xi-Sang Highway. Asphalt mixture with and without polyester fiber were used. Focus is on resistance of deformation at high temperature and flexibility at low temperature. Fiber-enhanced asphalt mixture with dynamic stability above 7000 passes/mm indicated excellent rutting resistance. The high temperature dynamic modulus of fiber-enhanced asphalt mixture was much higher than conventional SBS modified asphalt mixture. Three-point blending test result indicated that the maximum flexural strain of fiber-enhance asphalt mixture reached 4180μm/m. It was concluded that fiber-enhanced asphalt mixture was suit to be used in surface layer of the large longitudinal slope pavement of Xi-Sang Highway.


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