Comparative evaluation of fatigue resistance of warm fine aggregate asphalt mixtures

2016 ◽  
Vol 109 ◽  
pp. 8-16 ◽  
Author(s):  
Mohammed Sadeq ◽  
Hussain Al-Khalid ◽  
Eyad Masad ◽  
Okan Sirin
Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1508 ◽  
Author(s):  
Chenchen Zhang ◽  
Qi Ren ◽  
Zhendong Qian ◽  
Xudong Wang

High percentage reclaimed asphalt pavement (RAP) is prevailing in pavement engineering for its advantages in sustainability and environmental friendliness, however, its fatigue resistance remains a major concern. Fine aggregate matrix (FAM) is a crucial part in the fatigue resistance of asphalt mixtures with high RAP content. Hence, the linear amplitude sweep (LAS) test of FAM has been developed to study the fatigue resistance of asphalt mixtures. However, the torsional loading mode of the LAS test with a dynamic shear rheometer (DSR) is a limitation to simulate traffic load. In this paper, an alternative LAS test for FAM with high RAP content was proposed. Beam FAM specimens were tested using a dual-cantilever flexural loading fixture in a dynamic mechanical analyzer (DMA). To investigate the influence of RAP content and the rejuvenating agent (RA), four kinds of FAM mixes were tested with this method to study their fatigue resistance. The test results suggested that the repeatability of this alternative approach was reliable. A fatigue failure criterion based on maximum C × N was defined. Then, fatigue life prediction models based on viscoelastic continuum damage (VECD) analysis were established according to the LAS test results and validated by a strain-controlled time sweep (TS) test. It turned out that as RAP content increased, the modulus of FAM would be significantly raised, accompanied with a drop in the phase angle. The fatigue life of FAM would be greatly shortened when the RAP binder replacement rate reached 50%. Adding RA could considerably improve the dynamic properties of FAM mixes with high RAP content, resulting in a decrease in modulus, increase in phase angle and elongating fatigue life, but could not recover to the level of virgin binder.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2434
Author(s):  
Laura Moretti ◽  
Nico Fabrizi ◽  
Nicola Fiore ◽  
Antonio D’Andrea

In recent years, nanotechnology has sparked an interest in nanomodification of bituminous materials to increase the viscosity of asphalt binders and improves the rutting and fatigue resistance of asphalt mixtures. This paper presents the experimental results of laboratory tests on bituminous mixtures laid on a 1052 m-long test section built in Rome, Italy. Four asphalt mixtures for wearing and binder layer were considered: two polymer modified asphalt concretes (the former modified with the additive Superplast and the latter modified with styrene–butadiene–styrene), a “hard” graphene nanoplatelets (GNPs) modified asphalt concrete and a not-modified mixture. The indirect tensile strength, water sensitivity, stiffness modulus, and fatigue resistance of the mixtures were tested and compared. A statistical analysis based on the results has shown that the mixtures with GNPs have higher mechanical performances than the others: GNP could significantly improve the tested mechanical performances; further studies will be carried out to investigate its effect on rutting and skid resistance.


Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 128 ◽  
Author(s):  
Meng Chen ◽  
Barugahare Javilla ◽  
Wei Hong ◽  
Changluan Pan ◽  
Martin Riara ◽  
...  

This paper investigated the rheological properties of asphalt binder, asphalt mastic and asphalt mortar and the interaction between asphalt binder, mineral filler and fine aggregates. Asphalt binder, mastic and mortar can be regarded as the binding phase at different scales in asphalt concrete. Asphalt mastic is a blend of asphalt binder and mineral filler smaller than 0.075 mm while asphalt mortar consists of asphalt binder, mineral filler and fine aggregate smaller than 2.36 mm. The material compositions of mastic and mortar were determined from the commonly used asphalt mixtures. Dynamic shear rheometer was used to conduct rheological analysis on asphalt binder, mastic and mortar. The obtained test data on complex modulus and phase angle were used for the construction of rheological master curves and the investigation of asphalt-filler/aggregate interaction. Test results indicated a modulus increase of three- to five-fold with the addition of filler and a further increase of one to two orders of magnitude with cumulative addition of fine aggregates into asphalt binder. Fine aggregates resulted in a phase change for mortar at high temperatures and low frequencies. The filler had stronger physical interaction than fine aggregate with an interaction parameter of 1.8–2.8 and 1.15–1.35 respectively. Specific area could enhance asphalt-filler interaction. The mastic and mortar modulus can be well predicted based on asphalt binder modulus by using particle filling effect. Asphalt mortar had a significant modulus reinforcement and phase change and thus could be the closest subscale in terms of performance to that of asphalt mixtures. It could be a vital scale that bridges the gap between asphalt binder and asphalt mixtures in multiscale performance analysis.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 889 ◽  
Author(s):  
Haiqin Xu ◽  
Shaopeng Wu ◽  
Hechuan Li ◽  
Yuechao Zhao ◽  
Yang Lv

Steel slag, a by-product of steelmaking, imposes lots of negative impacts on the environment. For alleviating negative impacts, more and more experiments have been carried out to explore the application possibility of steel slag. The purpose of this study is to explore the feasibility of steel slag being applied in induction healing asphalt concretes to replace coarse and fine aggregate. Surface texture and pore sizes of steel slag were firstly tested, and then steel slag and basalt asphalt mixtures modified with steel fibers were prepared. Moisture susceptibility, dynamic stability, mechanical property, thermal property, induction heating speed, natural cooling speed and healing property of the asphalt mixtures were evaluated. Results showed that steel slags had more obvious holes in the surface while the surface area is much larger than that of basalt. Furthermore, steel fibers and steel slag both have dynamic stability, and steel fibers contribute to increased moisture resistance while steel slag is not. Steel slag asphalt concrete showed better mechanical property and better capacity to store heating. Steel slag asphalt mixtures had a similar heating speed to basalt asphalt mixtures but a significantly slower cooling rate. Finally, the induction healing test and CT scanning test demonstrated that steel slag asphalt mixtures had a similar healing ability to basalt asphalt mixtures. It can be concluded that steel slags have the potential to replace the natural aggregates to be applied in induction heating self-healing asphalt concretes.


2011 ◽  
Vol 225-226 ◽  
pp. 577-580
Author(s):  
Yong Ye ◽  
Yi Zhou Cai

The objective of this study is to investigate and evaluate the effect of fine aggregates (aggregate size smaller than or equal to 2.36 mm) on the compressive strength and creep behavior of asphalt mixtures. The variables that are considered in the study include the sizes and gradations of fine aggregate. A kind of standant aggregate gradation and four kinds of reduced aggregate gradation mixture specimens are used. Uniaxial compression and static creep tests were realized at different loading conditions. The test results showed that the different fine aggregate sizes do not result in significant differences in compressive strength and creep values using the same percentage of fine aggregates (38.4%). Only the different gradations showed a little differences for mixtures made with different gradations but same aggregate size (between 2.36 and 1.18 mm).


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