Investigation of the Effects of Evaporation Methods on the High-Temperature Rheological and Fatigue Performances of Emulsified Asphalt Residues

Yang Sun,Ri-Ran Wang,Jin-Chao Yue,De-Cai Wang,Rui-Xia Li

doi:10.1155/2020/4672413

Abstract

Cold recycling technology is a widely applied asphalt pavement rehabilitation technology. The properties of emulsified asphalt residues after water evaporates play an important role in the performance of the asphalt pavement. This paper investigates the rheological and fatigue properties of emulsified asphalt residues under different evaporation methods. Two different matrix asphalt binders and emulsifiers were selected to prepare the emulsified asphalt. Moreover, the direct heating method (DHM) and the EN13074 and ASTM D7497-09 evaporation methods were used to obtain emulsified asphalt residues. Furthermore, the linear viscoelasticity, the permanent deformation resistance, and the fatigue resistance were evaluated by the temperature sweep and frequency sweep tests, the multiple stress creep recovery (MSCR) test, and the linear amplitude sweep (LAS) test, respectively. The test results show that under the three evaporation conditions, the growth amplitude order of the rutting factor, recovery percent, complex modulus, and fatigue life of emulsified asphalt residues is ASTM D7497-09 > EN13074 > DHM, and as is the attenuation amplitude order of the nonrecoverable creep compliance and phase angle. The results reveal that the evaporation process leads to oxidation and hardening of the residues. The hardening degree of the ASTM D7497-09 evaporation method is higher than that of the EN13074 evaporation method, and the hardening degree of the EN13074 evaporation method is higher than that of the direct heating method. The rheological and fatigue performances of the emulsified asphalt residues depend on the matrix asphalt. Moreover, the residue that was prepared from 70# asphalt has good high-temperature and fatigue properties, but it has higher temperature sensitivity and stress sensitivity.

Highlights

Cold recycled mixture of emulsified asphalt has become one of the most popular approaches for asphalt pavement maintenance, rehabilitation, and reinforcement, with the advantage of excellent pavement performance, resource conservation, and environmental friendliness [1,2,3,4]
Conclusions and Recommendations is study investigated the effects of evaporation methods on the rheological and fatigue performances of emulsified asphalt residues using physical tests, linear viscoelastic property tests, permanent deformation resistance tests, and fatigue resistance tests. e following conclusions are obtained: (1) Under the three evaporation conditions, the penetration and ductility of residues obtained by the direct heating method are the largest, followed by those obtained by EN13074 evaporation method, and the penetration and ductility of residues obtained by the ASTM D7497-09 evaporation method are the smallest
(2) e growth amplitude order of the rutting factor and the recovery percent values of emulsified asphalt residues is ASTM D7497-09>EN13074>DHM, and as is the attenuation amplitude order by the nonrecoverable creep compliance. e overall results indicate that the residues obtained by ASTM D749709 suffered more serious aging than EN13074 and direct heating methods

Summary

Introduction

Cold recycled mixture of emulsified asphalt has become one of the most popular approaches for asphalt pavement maintenance, rehabilitation, and reinforcement, with the advantage of excellent pavement performance, resource conservation, and environmental friendliness [1,2,3,4]. Common residue recovery methods include distillation, evaporation, moisture analyzer balance (MAB) [11], and the SAFT (stirred air flow test with nitrogen) method [12]. Distillation methods, such as ASTM D6997 and ASTM D7403, are more scientific methods of residue collection and Advances in Materials Science and Engineering are more widely used to recover emulsion residue [13, 14]. Islam et al [19] prepared emulsified asphalt residue by the vacuum drying method and studied the effects of variables including the curing time, temperatures, and vacuum pressure on the rheological properties of the recovered asphalt emulsion residue. Xu et al [9] used the recovery method that was proposed by the EN13074 method (including both the recovery and stabilization processes at moderate temperatures) to obtain the residue, and the corresponding matrix asphalt binders were treated via the same method for comparison

Methods

Results

Conclusion