Investigation on Different Properties of Bitumen and Asphalt Mixtures Using Advanced Techniques

A special issue of Buildings (ISSN 2075-5309). This special issue belongs to the section "Building Materials, and Repair & Renovation".

Deadline for manuscript submissions: closed (30 August 2024) | Viewed by 13805

Special Issue Editors


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Guest Editor
School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410114, China
Interests: long-life pavement structure design theory and methods; high-performance pavement materials; pavement service performance; pavement digital twins; intelligent road construction and maintenance
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
National Engineering Research Center of Highway Maintenance Technology, Changsha University of Science and Technology, Changsha 410114, China
Interests: Long-term performance of asphalt pavement; fatigue performance; reclaimed asphalt pavement; bio-oil modified asphalt; machine learning
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Asphalt pavement has been subjected to the alternating and coupling effects of traffic load, water, light, heat, ice, and snow for a long time. The viscoelastic–plastic properties of bitumen make it susceptible to load changes and humid and hot environments, seriously affecting its service life and level of service, until it loses its essential functions. On the one hand, how to use advanced techniques to reveal the material and structural characteristics and performance evolution mechanism of asphalt mixtures under complex service conditions is a critical scientific issue. On the other hand, it is crucial to utilize advanced technology to enhance the resistance ability of bitumen and asphalt mixtures for complex service conditions. This Special Issue aims to use advanced techniques to characterize the various properties of bitumen and asphalt mixtures at multiple scales, including techniques such as microstructure characterization, phase analysis, composition analysis, thermal performance, functional application, and mechanical performance of traditional or multi-functional asphalt mixtures.

In this Special Issue, original research articles and reviews are welcome. Research areas may include (but are not limited to) the following:

  • Multi-scale analysis of bitumen and asphalt mixtures;
  • Smart/multifunctional asphalt mixture;
  • Numerical simulation;
  • Advanced testing technology for bitumen and asphalt mixtures;
  • The failure mechanism of asphalt and asphalt mixture;
  • Service performance of recycled asphalt pavement.

We look forward to receiving your contributions.

Prof. Dr. Songtao Lv
Dr. Xinghai Peng
Guest Editors

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Keywords

  • environmentally friendly materials
  • bio-asphalt
  • polymer-modified asphalt
  • recycled materials
  • modification mechanism and microscopic analysis
  • smart materials and structure
  • long life structure
  • numerical simulation
  • multifunctional pavement

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Published Papers (14 papers)

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Research

18 pages, 3222 KiB  
Article
Research on the Properties of Nano-Al2O3- and Nano-SiO2-Modified Bio-Asphalt and Mixtures
by Wei Qiao, Feilong Yuan, Xiaojian Xu and Qingzhou Wang
Buildings 2024, 14(11), 3366; https://doi.org/10.3390/buildings14113366 - 24 Oct 2024
Viewed by 409
Abstract
Bio-oil as a substitute or modifier for petroleum asphalt has significant environmental, economic, and sustainable development implications. However, the insufficient high-temperature and anti-aging characteristics of bio-asphalt lead to the limited application of bio-oil in road engineering. In this study, the characteristics of bio-asphalt [...] Read more.
Bio-oil as a substitute or modifier for petroleum asphalt has significant environmental, economic, and sustainable development implications. However, the insufficient high-temperature and anti-aging characteristics of bio-asphalt lead to the limited application of bio-oil in road engineering. In this study, the characteristics of bio-asphalt were reinforced by nano-Al2O3 and nano-SiO2. The nanomaterial-modified bio-asphalt was evaluated using basic characteristics, viscosity, and high- and low-temperature rheological characteristic tests. Meanwhile, the road behavior of nanomaterial-modified bio-asphalt mixtures was assessed. The test results demonstrated that incorporating bio-oil improved the low-temperature performance of PA. Compared with PA, BA’s ductility was increased by 83.87%. Nano-Al2O3 and nano-SiO2 positively affected the bio-asphalt’s temperature sensitivity and high-temperature and anti-aging characteristics but inhibited the low-temperature characteristics. Combining the results of the high- and low-temperature characteristics of nanomaterial-modified bio-asphalt, a nano-Al2O3 dosage between 4 and 6% or a nano-SiO2 dosage between 6 and 8% can realize the enhancement of high-temperature and anti-aging characteristics of bio-asphalt, and the low-temperature characteristics are better than those of petroleum asphalt. Meanwhile, the dynamic stability, crack resistance, and water loss resistance of the nanomaterial-modified bio-asphalt mixtures meet the specification requirements. The adjustable and designable high- and low-temperature characteristics of bio-asphalt can be realized by adjusting the dosage of nanomaterials. The application of bio-oil and nanomaterials promotes the resourceful utilization of waste and provides new possibilities for road engineering materials. Full article
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15 pages, 4062 KiB  
Article
Analysis of Equivalence between Loading Rate and Stress Level of Fatigue Characteristics of Asphalt Mixture
by Liang Tao, Zhengnan Liu and Xinglan Ding
Buildings 2024, 14(10), 3102; https://doi.org/10.3390/buildings14103102 - 27 Sep 2024
Viewed by 404
Abstract
The accurate characterization of fatigue life affects the durability and reliability of asphalt pavement for the asphalt mixtures. This paper proposed a new fatigue test method and analysis method which, in addition to increasing the accuracy of fatigue characterization, reduces the time and [...] Read more.
The accurate characterization of fatigue life affects the durability and reliability of asphalt pavement for the asphalt mixtures. This paper proposed a new fatigue test method and analysis method which, in addition to increasing the accuracy of fatigue characterization, reduces the time and cost consumed in laboratory tests of asphalt mixtures. According to the loading speed corresponding to different loading frequency and stress levels, the corresponding strength value is selected to determine the stress ratio in the fatigue equation. Therefore, the stress ratio can truly reflect the fatigue loading stress conditions and correspond to the fatigue loading speed one by one, avoiding the unscientific fatigue resistance design problem caused by the traditional S-N fatigue equation stress ratio, which takes a single strength value at a constant loading speed as the standard. Since the stress ratio takes into account the influence of loading speed under different loading frequencies and stress levels, a unified representation model of the fatigue equation of the asphalt mixture under different loading frequencies can be established; that is, the fatigue performance of the asphalt mixture under different loading frequencies can be normalized. The results showed that the loading rate in the strength test differed from the loading rate in the traditional fatigue test, which means that the fatigue curve could not be extended to point (1,1) when the fatigue equation was extended to a fatigue life Nf = 1. The fatigue test related to the velocity-dependent stress ratio in multiple experimental works, and data discreteness had a remarkable influence on fatigue characterization. The fatigue curve obtained by the fatigue equation under a constant loading rate was consistent with the fatigue curve under different loading rates. This method can reduce the duration of strength tests and the impact of the strength results of discreteness on fatigue characterization. The fatigue characterization model under constant loading rates considered the viscoelasticity of asphalt mixtures and guaranteed the correspondence of test conditions among stress level t, standard strength St, and fatigue life Nf. The stress levels and loading rates of the asphalt mixtures were confirmed to be equivalent. Furthermore, this paper established the relationship between strength and fatigue and obtained the fatigue life curve of the strength values. The fatigue performance of the asphalt mixtures is evaluated comprehensively. Full article
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18 pages, 4844 KiB  
Article
Dynamic Viscoelastic Behavior of Epoxy Asphalt Mixture under Four-Point Bending
by Baiqing He, Zhiyong Huang, Jingsong Chen, Mu He, Yan Wang, Jian Li and Shaohuai Wang
Buildings 2024, 14(10), 3061; https://doi.org/10.3390/buildings14103061 - 25 Sep 2024
Viewed by 502
Abstract
Given the dominant failure mode of steel bridge deck pavement layers, which is flexural–tensile damage, the dynamic modulus parameters conventionally determined through uniaxial compression testing are found to be inadequate for the design or performance analysis of these layers. In order to simulate [...] Read more.
Given the dominant failure mode of steel bridge deck pavement layers, which is flexural–tensile damage, the dynamic modulus parameters conventionally determined through uniaxial compression testing are found to be inadequate for the design or performance analysis of these layers. In order to simulate the actual stress of a pavement structure under wheel load, the four-point bending fatigue test method and uniaxial compression test method are used to measure the dynamic modulus of an epoxy asphalt mixture, and the differences between the two test methods are analyzed. Furthermore, the four-point bending fatigue test is employed to investigate the dynamic modulus and phase angle properties across varying temperatures and frequencies, facilitating the creation of master curves for these properties and utilizing Sigmoidal models to correlate dynamic modulus data at diverse temperature conditions. This study delves into the influence of epoxy resin content, mixture composition, and aging on the dynamic modulus. The experimental results show that the dynamic modulus measured by uniaxial compression exceeds that obtained from bending fatigue tests, with the difference initially increasing and then decreasing as temperature rises. This discrepancy significantly impacts the mechanical calculations of pavement layers, underscoring the importance of selecting the appropriate testing method. Temperature, frequency, and epoxy resin content have pronounced effects on the viscoelastic properties of the mixtures. Specifically, as temperature increases, the dynamic modulus undergoes a decrease, whereas the phase angle exhibits an increase. Additionally, the dynamic modulus augments with an increase in loading frequency, while the phase angle exhibits varied trends with frequency shifts across different temperatures. Both the WLF and Sigmoidal models are effective in constructing master curve representations for the dynamic flexural modulus and phase angle. The incorporation of epoxy resin transforms asphalt from a primarily viscous to a more elastic material, significantly enhancing the viscoelastic properties of the mixture. Notably, mixtures with 50% and 60% epoxy resin content exhibit comparable dynamic moduli and phase angles, while displaying notably superior performance compared to those with 40% epoxy resin content. For large-scale steel bridge deck pavement, 50% epoxy resin content is recommended. Moreover, epoxy asphalt mixtures demonstrate robust aging resistance, with minimal variations in the dynamic modulus and phase angle before and after aging. The research results can enable the acquisition of dynamic modulus and phase angle data in the whole temperature domain and the whole frequency domain, and provide reliable mixed performance parameters for the study of different application environmental performance of steel bridge deck pavement. Full article
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17 pages, 3791 KiB  
Article
Performance Evaluation of Soybean Oil/SBR Reclaimed Asphalt and Mixtures
by Yu Chen, Xiao Li and Xiaoge Tian
Buildings 2024, 14(7), 2085; https://doi.org/10.3390/buildings14072085 - 8 Jul 2024
Viewed by 683
Abstract
This study evaluated the properties of soybean oil/SBR reclaimed asphalt (SSRA). The optimal preparation method for SSRA was determined. Additionally, the feasibility of the optimal SSRA scheme was verified through asphalt mixture performance tests. With the soybean oil dosage enhanced, the penetration and [...] Read more.
This study evaluated the properties of soybean oil/SBR reclaimed asphalt (SSRA). The optimal preparation method for SSRA was determined. Additionally, the feasibility of the optimal SSRA scheme was verified through asphalt mixture performance tests. With the soybean oil dosage enhanced, the penetration and low-temperature rheological performance of SSRA were improved. The incorporation of soybean oil lowered the softening point, viscosity, and rutting index of aged asphalt. The softening points of SBR-4%+Oil-7.5% and SBR-6%+Oil-7.5% were 79.4 °C and 82.9 °C, respectively. The stiffness modulus of SBR-6%+oil-10% decreased by 35.37%. When the soybean oil dosage was 10% and the SBR dosage was 6% (SBR-6%+oil-10%), the properties of RTFOT+PAV aged asphalt were restored to those of its original state. The splitting tensile strength ratio of the SBR-6%+oil-10% mixture was 89%, with a decrease of 1.5% compared to the original asphalt mixture. The SBR-6%+oil-10% mixture exhibited improved high-temperature and low-temperature service properties. The total deformation of the SBR-6%+oil-10% mixture decreased by 8.43%, while its dynamic stability increased by 22.21%. This degree of improvement compared to the original asphalt mixture was not significant. The rejuvenation of the aged asphalt and mixture performance can mainly be attributed to the soybean oil supplementing the lost lightweight components of the aged asphalt, while SBR supplemented the degraded polymers. Utilizing soybean oil as a rejuvenating asphalt agent facilitates waste material recycling. Furthermore, this study provides a new idea for the recycling of polymer-modified asphalt and reclaimed asphalt pavement. Full article
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17 pages, 6053 KiB  
Article
Laboratory Performance and Micro-Characteristics of Asphalt Mastic Using Phosphorus Slag Powder as a Filler
by Xiao Li, Xiaoge Tian and Ronghua Ying
Buildings 2024, 14(7), 2061; https://doi.org/10.3390/buildings14072061 - 5 Jul 2024
Viewed by 613
Abstract
To evaluate the possibility of using phosphorus slag powder instead of mineral powder as a filler in asphalt mastic, this study investigates the micro-characteristics of phosphorus slag powder and its viscoelastic mechanical properties in asphalt mastic. A systematic approach combining macro and micro [...] Read more.
To evaluate the possibility of using phosphorus slag powder instead of mineral powder as a filler in asphalt mastic, this study investigates the micro-characteristics of phosphorus slag powder and its viscoelastic mechanical properties in asphalt mastic. A systematic approach combining macro and micro test methods was used to analyze the physical and surface characteristics, void structure, and surface energy of phosphorus slag powder. The viscoelastic mechanical properties of phosphorus slag powder were evaluated using appropriate indexes. Meanwhile, the correlations between and limitations of various evaluation indexes and the high-temperature rheological properties were identified. The results demonstrate that phosphorus slag powder exhibits low density, small overall particle size, difficulty in forming agglomerates, developed pores, large specific surface area, and high surface energy, which is suitable for replacing mineral powder as a filler in asphalt mastic. The main factors affecting the viscoelastic properties of asphalt mastic are the particle size and dosage of phosphorus slag powder. Generally speaking, phosphorus slag powder asphalt mastic with particle sizes ≤ 18 μm exhibits the best performance. In practical engineering applications, the appropriate dosage (7%, 10%, 13%) can be selected based on different regions and specific design and construction requirements. Additionally, zero-shear viscosity (ZSV), non-recoverable creep compliance (Jnr), and creep recovery percentage (R) exhibit a strong correlation with the high-temperature rheological properties of asphalt mastic. At the same time, the rutting factor (G*/sin δ) presents certain limitations. Full article
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18 pages, 3362 KiB  
Article
Assessment of Intelligent Unmanned Maintenance Construction for Asphalt Pavement Based on Fuzzy Comprehensive Evaluation and Analytical Hierarchy Process
by Gensheng Hu, Gongzuo Shi, Runhua Zhang, Jianfeng Chen, Haichang Wang and Junzhe Wang
Buildings 2024, 14(4), 1112; https://doi.org/10.3390/buildings14041112 - 16 Apr 2024
Cited by 2 | Viewed by 795
Abstract
Conventional human-involved maintenance methods for asphalt pavement pose significant challenges when applied to high-traffic road sections, often leading to congestion and safety risks, as well as reduced maintenance efficiency. In recent years, explorations into unmanned construction technology for newly constructed expressways have yielded [...] Read more.
Conventional human-involved maintenance methods for asphalt pavement pose significant challenges when applied to high-traffic road sections, often leading to congestion and safety risks, as well as reduced maintenance efficiency. In recent years, explorations into unmanned construction technology for newly constructed expressways have yielded beneficial and encouraging results. However, its application in road maintenance in more complex environments still needs to be expanded. In this study, an intelligent unmanned maintenance technology for asphalt pavement was applied to the Lilong Highway in Zhejiang Province, China, and the compactability, thickness, surface smoothness, permeability coefficient, and constructure depth of maintenance road sections were measured. Then, based on fuzzy comprehensive mathematics and the analytic hierarchy process, a comprehensive evaluation was performed on the intelligent unmanned maintenance technology, considering the aspects of road quality, safety, application, and socio-economic benefits. The results show that the road quality of intelligent unmanned maintenance technology can meet the road specification requirements. In addition, the membership degree of unmanned maintenance technology in the excellent grade is the highest, reaching 0.805, and the quantified value for the overall evaluation of the application effectiveness of unmanned maintenance technology is 92.10. This means that the final comprehensive evaluation result of unmanned maintenance technology is rated as excellent. The research findings provide decision-makers with valuable insights into the unmanned automation maintenance challenges faced by asphalt pavement, enabling them to implement appropriate measures to elevate the maintenance standards of road transportation. Full article
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21 pages, 3069 KiB  
Article
Nano-Scale and Macro-Scale Characterizations of the Effects of Recycled Plastics on Asphalt Binder Properties
by Ahmad Al-Hosainat, Munir D. Nazzal, Savas Kaya and Toufiq Reza
Buildings 2024, 14(3), 642; https://doi.org/10.3390/buildings14030642 - 29 Feb 2024
Viewed by 902
Abstract
This paper summarizes the results of one of the first comprehensive laboratory studies that was conducted to evaluate the effects of adding different contents of recycled polyethylene terephthalate (rPETE) as a modifier to an asphalt binder on the rheological and mechanical properties of [...] Read more.
This paper summarizes the results of one of the first comprehensive laboratory studies that was conducted to evaluate the effects of adding different contents of recycled polyethylene terephthalate (rPETE) as a modifier to an asphalt binder on the rheological and mechanical properties of the modified binder as well as on the agglomeration behavior between the rPETE and asphalt binder at a multiscale level. The high-temperature and low-temperature performances of the modified binder were investigated at the macro-scale and compared with those of the unmodified binder using dynamic shear rheometer (DSR) and bending-beam rheometer (BBR) rheological tests, as well as asphalt binder cracking device (ABCD) testing. The nano-scale evaluation of the binder properties, including the surface roughness, bonding energy, and reduced modulus, was accomplished using atomic force microscopy (AFM). The results indicated that the addition of rPETE enhanced the high- and intermediate-temperature rheological properties of the modified PG 64-22 binder. The low-temperature rheological properties and resistance to cracking decreased slightly with increasing rPETE content in the asphalt binder. However, this reduction was not remarkable when adding 4%, 8%, and 10% rPETE contents. The asphalt binder modified with 4% rPETE had a low-temperature grade of −22, similar to that of the unmodified binder, indicating that 4% rPETE can be added to the binder to improve its high- and intermediate-temperature properties without reducing its resistance to low-temperature damage. The AFM tapping-mode results indicated that the inclusion of rPETE in the asphalt binder improved the stiffness properties of the modified binder as compared with those of the control asphalt binder. In addition, the rPETE-modified binders showed rougher surfaces than the control binder. The addition of rPETE to the binder increased the values of the reduced modulus and bonding energy compared with those of the control binder. Full article
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21 pages, 5663 KiB  
Article
Performance Evaluation of a Multifunctional Road Marking Coating for Tunnels Based on Nano SiO2 and TiO2 Modifications
by Xiujie Quan, Liang Yang, Hui Li, Yan Chen and Shuang Shi
Buildings 2024, 14(2), 459; https://doi.org/10.3390/buildings14020459 - 7 Feb 2024
Viewed by 1180
Abstract
Multifunctional road marking coatings with the functions of high-temperature stability, degradation of exhaust gas, and self-cleaning are of great significance for the safe operation and environmental protection of tunnels. This article uses active acrylic resin and an organosilicon hydrophobic agent as the base [...] Read more.
Multifunctional road marking coatings with the functions of high-temperature stability, degradation of exhaust gas, and self-cleaning are of great significance for the safe operation and environmental protection of tunnels. This article uses active acrylic resin and an organosilicon hydrophobic agent as the base material, selects expanded vermiculite and glass microspheres as insulation fillers, and uses ammonium polyphosphate, pentaerythritol, melamine, and aluminum hydroxide as high-thermal-stability systems to prepare a two-component road marking coating base material. Then, nano SiO2 and modified nano TiO2 are added as modifiers to prepare a multifunctional road marking coating for tunnels. The physical and chemical properties of multifunctional road marking coatings are evaluating based on laboratory tests including thermogravimetry and derivative thermogravimetry, differential scanning calorimetry, infrared spectroscopy, scanning electron microscopy, exhaust degradation, and contact angle tests. The results indicate that the developed multifunctional road marking coating effectively reduces the thermal conductivity of the carbon layer through physical changes in the flame retardant system and the heat resistance formed by the high breaking bond energy of nano SiO2 during the combustion process. It forms a ceramic-like structure of titanium pyrophosphate with nano TiO2 that is beneficial for improving flame retardancy without generating harmful volatile gases and has good flame retardant properties. N–V co-doping reduces the bandgap of TiO2, broadens the absorption range of visible light by nano TiO2, improves the catalytic efficiency of visible light, and achieves the degradation efficiency of the four harmful components NOx, HC, CO, and CO2 in automotive exhaust by 23.4%, 8.3%, 2.5%, and 2.9%, respectively. The solid–liquid phase separation in the multifunctional road marking coating in the tunnel causes the formation and accumulation of nano SiO2 and TiO2 particles on the coating surface, resulting in a microstructure similar to the “micro–nano micro-convex” on the lotus leaf surface and making a water droplet contact angle of 134.2° on the coating surface. Full article
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20 pages, 10190 KiB  
Article
Improvement of the Cracking Moment-Based Asphalt Mixture Splitting Test Method and Splitting Strength Research
by Hongxin Guan, Wang Pan, Hairong Yang and Yuxuan Yang
Buildings 2024, 14(2), 457; https://doi.org/10.3390/buildings14020457 - 7 Feb 2024
Viewed by 852
Abstract
The asphalt mixture splitting test is one of the most important methods for measuring asphalt’s tensile properties. To characterize the limitations of the traditional splitting test and the influence of the specimen size and loading conditions on the accuracy of the test, the [...] Read more.
The asphalt mixture splitting test is one of the most important methods for measuring asphalt’s tensile properties. To characterize the limitations of the traditional splitting test and the influence of the specimen size and loading conditions on the accuracy of the test, the factors affecting the strength of the splitting test were analyzed to reveal the splitting failure state and establish a unified representation model between the splitting and direct tensile tests. Initially, the moment of specimen cracking was taken as a key indicator, combined with image processing technology, to establish a set of criteria to judge the splitting test. Subsequently, standardized splitting tests were conducted and compared to tests of different specimen sizes and loading methods. Based on the octahedral strength theory, the stress points before and after the improved test were compared to the existing failure criteria. Direct tensile and splitting tests were conducted at different rates, and a unified strength–rate function model was established, realizing the unified representation of direct tensile and splitting tests. The research results indicate that the standardized splitting test is prone to the phenomenon wherein the specimen end face cracks before the center, affecting the accuracy of the test and potentially leading to redundant material strength evaluations. Using a loading method with a “35 mm specimen thickness” and a “0.3 mm rubber gasket + 12.7 mm arc-shaped batten” can essentially achieve the test hypothesis of “cracking at the center first”, resulting in less discrete outcomes and closer alignment to the three-dimensional stress failure state. The tensile and splitting strengths are both power function relationships with the rate as the independent variable, establishing a unified function model of the tensile and failure strengths. The research provides a more reliable testing method and calculation model for asphalt pavement structure design, and it also provides an effective basis for the improvement of splitting tests on materials such as concrete and rock. Full article
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21 pages, 4080 KiB  
Article
Study of Low-Content Epoxy Asphalt Mixture Applied to the Road
by Xiaodong Li, Chuanxi Luo, Shaohuai Wang, Xiang Long, Yan Wang, Jian Li and Mu He
Buildings 2024, 14(2), 443; https://doi.org/10.3390/buildings14020443 - 6 Feb 2024
Viewed by 1011
Abstract
To realize the application of epoxy asphalt concrete on roads and solve the problem of the high cost of epoxy asphalt concrete and the causes of bulging in the construction process, a low-content epoxy asphalt mixture was experimentally studied. Rheological and microscopic tests [...] Read more.
To realize the application of epoxy asphalt concrete on roads and solve the problem of the high cost of epoxy asphalt concrete and the causes of bulging in the construction process, a low-content epoxy asphalt mixture was experimentally studied. Rheological and microscopic tests were carried out to study its performance. At the same time, 17 kinds of low-content asphalt mixture Marshall test pieces and rut plate test pieces with different oil stone ratios were made. Their road performances were tested, and a watertight breathable epoxy asphalt mixture was studied to solve the bulging problem. The research shows that, for ordinary roads, a content of epoxy resin of 10–15% can meet both the high-temperature and the low-temperature requirements. For sections with special rutting resistance requirements, a controlled epoxy resin content between 15 and 30% is recommended. When the content of epoxy resin is greater than 30%, epoxy asphalt initially forms a crosslinked spatial network. An epoxy asphalt with a complex structure from asphaltene to epoxy, with ultra-high performance, can be used for small steel bridge pavements. A BBR test showed that, with an increase in epoxy resin content, the low-temperature performance of asphalt gradually weakens. When the content was 20%, epoxy asphalt’s low-temperature performance was weaker than that of SBS-modified asphalt. Under extremely low-temperature conditions, the performance of epoxy asphalt could not meet the specifications. When the voids of low equivalent epoxy asphalt mixture are controlled at 4.1–4.5%, it is watertight and breathable; this can solve the problem of bulging and greatly reduce the cost of projects. Full article
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28 pages, 8142 KiB  
Article
Experimental Study on Dynamic Modulus of High Content Rubber Asphalt Mixture
by Guozhi Zheng, Naitian Zhang and Songtao Lv
Buildings 2024, 14(2), 434; https://doi.org/10.3390/buildings14020434 - 5 Feb 2024
Cited by 5 | Viewed by 1387
Abstract
Currently, the research on the mechanical properties of rubber-modified asphalt mixtures primarily focuses on small-scale investigations, with insufficient exploration into the performance of rubber particles and their relationship with the mechanism and properties of modified asphalt mixtures. Limited studies have been conducted on [...] Read more.
Currently, the research on the mechanical properties of rubber-modified asphalt mixtures primarily focuses on small-scale investigations, with insufficient exploration into the performance of rubber particles and their relationship with the mechanism and properties of modified asphalt mixtures. Limited studies have been conducted on large-scale rubber modification in asphalt mixtures. Due to frequent use and subsequent high damage to existing asphalt pavements, incorporating rubber-modified asphalt mixtures can partially alleviate premature deterioration. Dynamic modulus tests were conducted using MTS equipment under unconfined conditions to investigate the viscoelastic behavior of rubber-modified asphalt mixtures with high rubber content and elucidate the influence of rubber particle content on the elastic deformation and recovery capability. The dynamic mechanical properties of the mixtures were determined at different loading rates, temperatures, and types of rubber-modified asphalt mixtures. Based on the test data, variations in the dynamic modulus, phase angle, storage modulus, loss modulus, loss factor, and rut factor of the rubber-modified asphalt mixtures under different loading frequencies, temperatures, and types were analyzed. The results demonstrate the pronounced viscoelastic behavior of rubber-modified asphalt mixtures. The mixtures exhibit enhanced elasticity at low temperatures and high frequencies, while their viscosity becomes more prominent at high temperatures and low frequencies. Under constant test temperatures, an increase in load loading frequency leads to a higher dynamic modulus; conversely, a decrease in dynamic modulus is observed with increasing test temperatures. The dynamic modulus of ARHM-25 at a frequency of 10 Hz is found to be 12.99 times higher at 15 °C compared to that at 60 °C, while at 30 °C, the dynamic modulus at 25 Hz is observed to be 2.72 times greater than that at 0.1 Hz. Furthermore, the rutting resistance factors of the asphalt mixtures increase with loading frequency but decrease with temperature. The rutting factor for ARHM-13 at a frequency of 10 Hz is found to be 22.98 times higher at 15 °C compared to that at 60 °C, while at a temperature of 30 °C, the rutting factor for this material is observed to be 3.09 times greater at a frequency of 25 Hz than at 0.1 Hz. These findings suggest that rutting is most likely when vehicles drive at low speeds in hot weather conditions. Full article
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29 pages, 9566 KiB  
Article
Comparative Study on the Dynamic Response of Asphalt Pavement Structures: Analysis Using the Classic Kelvin, Maxwell, and Three-Parameter Solid Models
by Yonghai He, Songtao Lv, Nasi Xie, Huilin Meng, Wei Lei, Changyu Pu, Huabao Ma, Ziyang Wang, Guozhi Zheng and Xinghai Peng
Buildings 2024, 14(1), 295; https://doi.org/10.3390/buildings14010295 - 22 Jan 2024
Cited by 1 | Viewed by 1343
Abstract
This study addressed the complex problems of selecting a constitutive model to objectively characterize asphalt mixtures and accurately determine their viscoelastic properties, which are influenced by numerous variables. Inaccuracies in model or parameter determination can result in significant discrepancies between the calculated and [...] Read more.
This study addressed the complex problems of selecting a constitutive model to objectively characterize asphalt mixtures and accurately determine their viscoelastic properties, which are influenced by numerous variables. Inaccuracies in model or parameter determination can result in significant discrepancies between the calculated and measured results of the pavement’s structural dynamic response. To address this, the research utilized the physical engineering principles of asphalt pavement structure to perform dynamic modulus tests on three types of high-content rubberized asphalt mixtures (HCRAM) within the surface layer. The research aimed to investigate the influencing factors of the dynamic modulus and establish a comprehensive master curve. This study also critically evaluated the capabilities of three viscoelastic models—the three-parameter solid model, the classical Maxwell model, and the classical Kelvin model—in depicting the dynamic modulus of HCRAM. The findings indicated a negative correlation between the dynamic modulus of the asphalt mixture and temperature, while a positive association exists between the loading frequency and temperature, with the impact of the loading frequency diminishing as the temperature increases. Notably, the three-parameter solid model was identified as the most accurate in describing the viscoelastic properties of the HCRAM. Furthermore, the dynamic response calculations revealed that most indexes in the surface layer’s dynamic response are highest when evaluated using the three-parameter viscoelastic model, underscoring its potential to enhance the pavement performance’s predictive accuracy. This research provides valuable insights into optimizing the material performance and guiding the pavement design and maintenance strategies. Full article
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22 pages, 8076 KiB  
Article
Research on the Modulus Decay Model under a Three-Dimensional Stress State of Asphalt Mixture during Fatigue Damage
by Yonghai He, Songtao Lv, Ziyang Wang, Huabao Ma, Wei Lei, Changyu Pu, Huilin Meng, Nasi Xie and Xinghai Peng
Buildings 2023, 13(10), 2570; https://doi.org/10.3390/buildings13102570 - 11 Oct 2023
Cited by 3 | Viewed by 1161
Abstract
Fatigue damage can develop within asphalt pavement due to the continuous impact of driving loads and natural elements. Understanding the process of asphalt mixtures’ fatigue damage is crucial for guiding the design, maintenance, and repair of asphalt pavement. This research aims to establish [...] Read more.
Fatigue damage can develop within asphalt pavement due to the continuous impact of driving loads and natural elements. Understanding the process of asphalt mixtures’ fatigue damage is crucial for guiding the design, maintenance, and repair of asphalt pavement. This research aims to establish a model that characterizes the mixtures’ modulus decay under a three-dimensional (3-D) stress state. Firstly, asphalt mixes were subjected to direct tensile (DT), indirect tensile (IDT), unconfined compressive (UC) strength and fatigue tests, and the resulting data were analyzed. Then, modulus decay models under DT, IDT, and UC conditions were established, and the modulus decay patterns under the three loading modes were compared and analyzed. Finally, using the fatigue stress strength ratio Δ (a fatigue resistance index for asphalt mixtures that takes into account the impacts of stress state and loading rate), a unified characterization model for asphalt mixes’ modulus decay under a 3-D stress state was created. According to the study’s findings, asphalt mixes’ modulus decay during fatigue damage exhibits obvious nonlinear characteristics. While the asphalt mixes’ modulus decay law with various loading modalities is similar under the same conditions, the decay rate may differ. Essentially, the speed of the modulus decay of a certain asphalt mixture primarily depends on the value of Δ during service. A larger Δ indicates a faster modulus decay. This study offers a theoretical foundation for the conversion from material fatigue damage to structural fatigue damage, which is vital for enhancing the asphalt pavements’ construction quality and longevity. Full article
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19 pages, 5181 KiB  
Article
Rheological Properties and Microscopic Morphology Evaluation of UHMWPE-Modified Corn Stover Oil Bio-Asphalt
by Jian Li, Chuanxi Luo, Jixing Jie and Haobin Cui
Buildings 2023, 13(9), 2167; https://doi.org/10.3390/buildings13092167 - 26 Aug 2023
Cited by 4 | Viewed by 1031
Abstract
In order to promote the efficient utilization of bio-oil, corn stover oil and petroleum asphalt were used to prepare bio-asphalt. UHMWPE was adopted to strengthen the high-temperature properties of bio-asphalt. UHMWPE-modified corn stover oil asphalt was prepared. Rheological and microscopic tests were carried [...] Read more.
In order to promote the efficient utilization of bio-oil, corn stover oil and petroleum asphalt were used to prepare bio-asphalt. UHMWPE was adopted to strengthen the high-temperature properties of bio-asphalt. UHMWPE-modified corn stover oil asphalt was prepared. Rheological and microscopic tests were carried out to study its performance. The softening point and viscosity of the modified asphalt were enhanced with a rise in the UHMWPE dosage. Its ductility and deformation ability increased at 5 °C. An MSCR test suggested that the asphalt’s creep recovery ability and anti-rutting properties decreased at a high stress level. Meanwhile, the low-temperature rheological behavior of UHMWPE-modified corn stover oil asphalt was superior to that of neat asphalt. The corn stover oil ameliorated the asphalt’s low-temperature properties but weakened its high-temperature behavior. The optimal preparation schemes for UHMWPE-modified corn stover oil asphalt were recommended through a comprehensive analysis of the properties. The recommended dosage of UHMWPE was 3–4%, while the corn stover oil dosage was 5%. However, when the dosage of corn stover oil was 10%, the recommended dosage of UHMWPE was 4%. UHMWPE powder was melted and cross-linked with neat asphalt during high-temperature preparation, demonstrating that UHMWPE can enhance the properties of asphalt. The UHMWPE polymer macromolecules can be dispersed in corn stover oil. UHMWPE can form a compact and robust network structure with asphalt. The feasible application of corn stover oil in road engineering was verified, which provides efficient solutions for waste utilization. This study will contribute to the sustainable development of road construction. Full article
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