Laboratory Evaluation of Rheological Properties of Asphalt Binder Modified by Nano-TiO<sub>2</sub>/CaCO<sub>3</sub>

Zhang, Liming; Gao, Xuekai; Wang, Wensheng; Wang, Hua; Zheng, Kunkun

doi:https://doi.org/10.1155/2021/5522025

Advances in Materials Science and Engineering

On this page

Abstract Introduction Methods Results and Discussion Conclusions Data Availability Conflicts of Interest Acknowledgments References Copyright Related Articles

Special Issue

High-Performance Materials and Advanced Characterization Methods for Durable Pavement

View this Special Issue

Research Article | Open Access

Volume 2021 | Article ID 5522025 | https://doi.org/10.1155/2021/5522025

Laboratory Evaluation of Rheological Properties of Asphalt Binder Modified by Nano-TiO₂/CaCO₃

Liming Zhang,^1,2Xuekai Gao,³Wensheng Wang,¹Hua Wang,^4,5and Kunkun Zheng⁶

Academic Editor: Shuaicheng Guo

Received11 Jan 2021

Revised21 Jan 2021

Accepted02 Feb 2021

Published12 Feb 2021

Abstract

Nanomaterials have a great potential for enhancing the performance of base asphalt binder. This study aims to promote the application of nano-TiO₂/CaCO₃ in bitumen and presents a study on rheological properties for TiO₂/CaCO₃ nanoparticle-bitumen. In this study, a series of laboratory experiments have been performed for bitumen with different nano-TiO₂/CaCO₃ dosages. Nano-TiO₂/CaCO₃-modified bitumen with optimum dosage was prepared for viscosity, dynamic shear rheometer (DSR), and beam bending rheometer (BBR) for assessing temperature sensitivity of bitumen, and the low-medium-high-temperature performances were analyzed for TiO₂/CaCO₃ nanoparticle-bitumen as well. Results show that bituminous mechanical properties were enhanced by TiO₂/CaCO₃, and based on the overall desirability analysis of various conventional tests, the reasonable dosage of nano-TiO₂/CaCO₃ was recommended as 5% by weight of base bitumen. Adding nano-TiO₂/CaCO₃ was beneficial to improve the viscosity and reduce the temperature sensitivity of bitumen. The capacities of bituminous rutting resistance as well as medium-temperature fatigue resistance were enhanced by the addition of nano-TiO₂/CaCO₃. However, BBR test shows that bituminous anticracking is reduced slightly. On this basis, the Burgers model is selected for clarifying the decrease in anticracking performance; that is, nano-TiO₂/CaCO₃ increased the stiffness modulus while increasing the viscosity of bitumen.

1. Introduction

Bituminous pavement with its superior performances has become one of the most important pavement types in China [1–4]. With the development of society, bituminous pavement-related technology and measurements have also been continuously developed, and its service performances and level have been significantly improved [5–10]. However, it is worth noting that there are yet many problems in the field of flexible pavement which need to be solved urgently. Bituminous material has a significant feature that its properties are strongly influenced by its service temperature [11–13]. The resulting damage will reduce the service performance of bituminous flexible materials, such as rutting, cracks, and other damage phenomena [2, 14–18].

In general, there are many factors affecting the performance degradation of bituminous flexible materials, including material internal factors and service condition factors [19]. A lot of related research works have been done, including modifying bituminous materials [20, 21] and optimizing bituminous flexible pavement structure [22]. However, with the rapid development of nanotechnology, more and more researchers are committed to introducing nanomaterials to modify bitumen [23]. Nanomaterials refer to materials in the range of 1∼100 nanometers in at least one dimension. It has previously been observed that the physical, chemical, and other properties of nanomaterials have great differences from the original raw materials [24]. It is worth noting that nanomaterials usually have the advantages of significant temperature susceptibility, better extendability, larger specific surface area (SSA), and so on. Therefore, on the above basis, researchers introduced nanomaterials into road and construction fields. Jahromi et al. employed two kinds of nanoclay to improve the performances of bituminous materials. According to X-ray diffraction along with dynamic shear rheometer (DSR) tests, nanoclay modified bitumen increased stiffness and decreased phase angle [25]. Abdelrahma et al. assessed the physical performances of bitumen through adding the modified nanoclay using dynamic mechanical analysis and showed that the incorporation of modified nanoclay materials into bituminous materials enhanced their physical properties. Also, they investigated the modification mechanism of nanoclay, which was considered to be the interactivity of the modified nanosilica tetrahedron in bitumen using the FTIR test [26]. You et al. used nanoclay to modify bitumen and compared two kinds of nanoclay. The results indicated that nanoclay could effectively boost the comprehensive performances of bituminous materials. Furthermore, the blending procedure was considered as the key to achieving a well-distributed nanoclay modified bitumen [27]. Khattak et al. employed different dosages of carbon nanofibers to modify three types of bituminous cement based on two bituminous mixing procedures, i.e., dry and wet procedures. Due to the larger SSA and better interface combination effect as well as higher modulus values of carbon nanofiber, the test results showed that carbon nanofiber-modified bitumen exhibited good viscoelastic response and fatigue performances [28]. Chen et al. utilized nano-TiO₂ to modify bitumen through permeability technology and evaluated the penetration effect using a scanning electron microscope. Because of the large surface area and advanced oxidation technology of nano-TiO₂, nano-TiO₂-modified bitumen produced good performances of bitumen and also had a good environment purification function [29]. Because of SSA and good dispersion as well as stability of nanosilica, it was applied to medicine, engineering, and so on. It was found that the performances of bituminous materials were greatly enhanced through incorporating nanosilica [30]. Yusoff et al. thought that sensitivity to moisture damage of polymer-modified bituminous materials was decreased while their antirutting and fatigue performances were increased through incorporating nanosilica [31]. Using the mentioned nanomaterials could significantly boost the ability of bituminous flexible pavement to reply to service conditions, for instance, its antirutting and cracking [32, 33].

On the other hand, considering the typical viscoelastic-plastic characteristics of bituminous flexible pavement under its service conditions, there are still inescapable deformations [34–37]. Despite various technical measures, there are still many problems related to deformation resistance of bituminous flexible pavement including ruts, cracks, and other deformation damage phenomena, which can be attributed to the insufficient deformation resistance [38, 39]. Consequently, it is quite essential to discuss and evaluate the deformation performance of bituminous materials from the perspective of the viscoelastic constitutive model. Liu et al. proposed two methods to construct the master curves for bituminous concretes based on Kramers-Kronig relations [40]. Lagos-Varas et al. developed a new method of viscoelastic mechanical behaviors based on derivatives of fractional order, which can well describe the practical construction and be suitable for modified bitumen [41]. Wang et al. prepared the polymer and basalt fiber-modified bituminous mixtures by Superpave gyratory compaction and assessed viscoelastic properties under F-T [42]. Ma et al. performed laboratory tests and virtual creep tests based on discrete element technology for viscoelastic behavior of bituminous materials considering multiple ingredients [43]. Darabi et al. investigated viscoelastic behaviors of bituminous mixture. Then they applied laboratory experiments to verify mechanical response [44].

The objective of this work is to carry out a study on rheological performances of bitumen containing nano-TiO₂/CaCO₃. Firstly, a series of experiments have been performed for bitumen with different dosages of nano-TiO₂/CaCO₃ to confirm the nano-TiO₂/CaCO₃ dosage. After that, modified bitumen with optimum dosage was prepared for rotational viscosity test and DSR as well as beam bending rheometer (BBR) for assessing temperature sensitivity. Meanwhile, the low-medium-high-temperature performances of nano-TiO₂/CaCO₃-modified bitumen were discussed as well. On this basis, bituminous viscoelastic behavior is analyzed using the Burgers model.

2. Experimental Materials and Methods

2.1. Materials and Tested Specimens

2.1.1. Base Bitumen

The 90# base bitumen AH-90 is acquired from Panjin, China, and the main technical indicators are in Table 1.

2.1.2. Nano-TiO₂/CaCO₃

The nano-TiO₂/CaCO₃ was developed and provided by the College of Chemistry, Jilin University. Table 2 is the detailed technical characteristics. Figure 1 shows the SEM image of nano-TiO₂/CaCO₃.

2.1.3. TiO₂/CaCO₃ Nanoparticle-Bitumen

Nano-TiO₂/CaCO₃ was added to base bitumen to prepare nano-TiO₂/CaCO₃-modified bitumen with a percentage dosage of 3%, 4%, 5%, 6%, 7%, 8%, and 9% of the total base bitumen by weight [45, 46]. As shown in Figure 2, the sample preparation procedure is as follows [45, 47]: base original bituminous material was preheated to 160°C and next it was blended with modified nano-TiO₂/CaCO₃ with manually stirring for 5 min. The corresponding temperature increased to 170°C in a short time. Finally, the high-speed shearing was carried out with a revolution of 6000 r/min at 170°C for 40 min. Before use, heat the bitumen sample again to 170°C, control the shearing speed at 450∼600 r/min, and stir continuously for 20 min.

2.2. Laboratory Tests of Bitumen

2.2.1. Conventional Tests of Bitumen

The penetration test is performed to assess the consistency of bitumen, which is carried out at 25°C following JTG E20-2011 T0604. The softening point (SP) test is adopted for bituminous materials. Then using measured values, penetration index (PI) can be calculated, which generally describes and evaluates the temperature sensitivity of bitumen quantitatively. And the PI equation expression is [48]

Ductility property is measured by the ductility test. Bituminous samples with standard size are stretched until broken with a stretching rate at 10°C. Ductility value is defined as the stretched distance at breaking.

In view of the above different trends of conventional physical performances of modified bitumen with various nano-TiO₂/CaCO₃ dosages, the overall analysis is required, and the overall desirability (OD) is selected for normalization and analysis. The conventional physical properties of modified bitumen are normalized based on different desirability, which are defined as follows [48]:in which and are the k-th original and normalized values in the i-th physical property, respectively. m is the number of conventional physical properties.

2.2.2. Rotational Viscosity Test

Bitumen may exhibit non-Newtonian behavior within service temperature range and its viscosity coefficient is not constant. The Brookfield rotational viscometer was adopted, which is maintained in a chamber. As described in JTG E20-2011 T0625, the torque and rotation rate are adopted to calculate the apparent viscosity of bitumen. The test temperature is arranged from low to high.

To quantitatively express the sensitivity of bitumen to temperature, viscosity-temperature susceptibility (VTS) was adopted for assessing temperature sensitivity in this study, and its calculation equation is shown as follows:where η₁ and η₂ are the corresponding viscosity at temperatures T₁ and T₂ (herein, T₁ = 60°C and T₂ = 135°C).

2.2.3. Dynamic Shear Rheometer Test

DSR developed by SHRP was employed for the sake of analyzing the dynamic characteristics and evaluating the viscoelastic behavior of bituminous materials [48–50]. Compared to static experiments (penetration, softening point, etc.), the DSR test has more intuitive and real advantages to assess the properties of bituminous materials. Following the specification ASTM D7175, the rheological parameters of bituminous materials are determined by Malvern Bohlin Gemini 150.

In the DSR test, the dynamic viscoelastic behavior of bitumen can be divided into two parts, including G^∗ and δ [4, 51, 52]. G^∗ is calculated by applying dynamic shear stress (τ_max) to bituminous sample, γ_max, defined by

The phase angle (δ) reflects the ratio of viscoelasticity in bitumen. Under the condition of high-temperature or low-frequency loading, bitumen is more prone to viscous flow, so the phase angle is larger, while under the condition of low-temperature or high-frequency loading, bitumen exhibits more elastic properties and the phase angle is smaller.

2.2.4. Beam Bending Rheometer Test

BBR test is a method for measuring the hardness of bituminous beam with a dimension of 6.25 × 12.5 × 127 mm under creep loading based on the theory of engineering beam [48]. Two parameters can be obtained from the deflection curves versus time, that is, S (t) and m-value. Their equations are expressed in equations (5)–(7):

The flowchart of experimental design for this study is shown in Figure 3. Three replicates for each specimen were tested and measured.

3. Results and Discussion

3.1. Optimum Content of Nano-TiO₂/CaCO₃

3.1.1. Conventional Tests of Nano-TiO₂/CaCO₃-Modified Bitumen

The experimental results of conventional physical performances of modified bitumen with various percentages of nano-TiO₂/CaCO₃ are plotted in Figure 4. It is observed that the penetration at 25°C decreases and the SP value becomes larger with the increasing of nano-TiO₂/CaCO₃, but their variation slope becomes smaller gradually when the percentage of nano-TiO₂/CaCO₃ is more than 5%. The ductility at 10°C decreases fast firstly and then decreases slowly but finally decreases significantly. The above changing trend indicates that nano-TiO₂/CaCO₃ would reduce the sensitivity of bitumen to temperature, which was consistent with the analysis results by Cheng et al. [53].

(a)

(b)

(c)

(d)

Penetration decreases significantly first and then tends to stabilize with nano-TiO₂/CaCO₃ increasing in Figure 4(a), which shows that adding nano-TiO₂/CaCO₃ reduced the sensitivity of bitumen to temperature. From Figure 4(b), SP increases significantly and then changes slightly when nano-TiO₂/CaCO₃ content increases. As shown in Figure 4(c), the PI shows a changing trend from increasing to decreasing. In addition, in Figure 4(d), the ductility of modified bitumen at 10°C also shows a changing trend of decreasing. The ductility at 10°C is the largest value at the nano-TiO₂/CaCO₃ content of 3%. Next, the ductility at 10°C decreases again and the variation slope increased. The ductility results indicate that nano-TiO₂/CaCO₃ would enhance the low-temperature extendability of modified bitumen to some extent, but the low-temperature property of modified bitumen may be damaged when the dosage of nano-TiO₂/CaCO₃ is too high. The modifier nano-TiO₂/CaCO₃ can absorb the light components in asphalt, but when the modifier content is too high, its absorption effect has already reached the best, but the effect is not significant, which was also consistent with the analysis results by Cheng et al. [53].

Table 3 presents the OD analysis. There is different desirability for different physical properties. For the OD analysis results of nano-TiO₂/CaCO₃-modified bitumen, the OD value (γ(k)) increases first, but the OD value becomes smaller when nano-TiO₂/CaCO₃ content is larger than 5%. Thus, a reasonable percentage of TiO₂/CaCO₃ is 5% by mass of base bitumen [48].

3.1.2. Technical Indicators of TiO₂/CaCO₃ Nanoparticle-Bitumen

Table 4 presents the main technical properties of nano-TiO₂/CaCO₃-bitumen. Adding nano-TiO₂/CaCO₃ decreases the penetration of modified bitumen. The 90# base bitumen with nano-TiO₂/CaCO₃ is equivalent to the 70# bitumen, which indicates that the consistency of the bitumen has been significantly improved. Meanwhile, the softening point of nano-TiO₂/CaCO₃-modified bitumen has increased by about 3°C, and the dynamic viscosity at 60°C has increased by about 6%. The high-temperature resistance of bitumen is significantly enhanced by nano-TiO₂/CaCO₃. The ductility reduced, indicating that modified bitumen still has a good low-temperature property.

3.2. Rotational Viscosity Test

The viscosity of bitumen was tested, which is presented in Figure 5. The slope represents bituminous sensitivity. As seen from Figure 5, the temperature sensitivity of 90# base bitumen is higher, while the nano-TiO₂/CaCO₃-modified bitumen reduced the temperature sensitivity.

According to equation (3), the VTS results are as follows: the VTS of base bitumen is −3.471 and the VTS of nano-TiO₂/CaCO₃-modified bitumen is −3.207. By comparison, the absolute VTS value of TiO₂/CaCO₃ nanoparticle-bitumen is smaller by comparison, which is approximately reduced by 7.6%. This indicates that nano-TiO₂/CaCO₃ would reduce the temperature sensitivity of bitumen. This may be because the light components in asphalt are absorbed by nanoparticles, which makes the resin and asphaltene in asphalt increase and the adhesive force increase [54]. The viscosity at 135°C (0.415 Pa∙s) of nano-TiO₂/CaCO₃-modified bitumen does not exceed 3 Pa∙s. The preparation condition for nano-TiO₂/CaCO₃-modified bitumen is about 5°C higher than that of base bitumen, but much lower than other types of commonly used polymer-modified bitumen, which could enhance the construction cheapness of bituminous pavement to some extent.

3.3. Dynamic Shear Rheometer Test

3.3.1. Complex Shear Modulus (G^∗) and Phase Angle (δ)

Bitumen has significant temperature sensitivity and has different mechanical properties at different temperatures. To explore the rheological characteristics of bituminous binder in medium- and high-temperature ranges, the DSR test was conducted at 10 rad/s, 10∼80°C, and the strain was controlled as 12%. The measured G^∗ and δ versus temperature were plotted in Figure 6.

(a)

(b)

Values G^∗ decrease with test temperature increasing. Because bituminous fluidity rises with temperature, and it is prone to show more significant deformation at the same stress level. Clearly, a higher complex shear modulus is generally required to ensure that bituminous pavement still has a good resistance to high-temperature deformation. Furthermore, the complex shear modulus of nano-TiO₂/CaCO₃-modified bitumen is 4.8% lower at 10°C, while by comparison, the complex shear modulus of nano-TiO₂/CaCO₃-modified bitumen is 12.8% higher at 80°C. This indicates that the nano-TiO₂/CaCO₃-modified bitumen has higher temperature stability than base original bitumen due to the higher complex shear modulus at high temperatures.

The characteristics (δ) is the relative indicatrix between recoverable and unrecoverable deformation, in which δ = 0° for elastic solids and δ = 90° for viscous fluids. Values δ of base as well as nano-TiO₂/CaCO₃-modified bitumen increase as test temperature increases, which fully reflects the characteristics of a viscous fluid for bitumen as a typical viscoelastic material. The phase angle of base bitumen changes 28.3°, and the δ values change 26.2° for the modified bitumen. This indicates that nano-TiO₂/CaCO₃-bitumen possesses little sensitivity compared with base one. Moreover, since flow deformation of nano-TiO₂/CaCO₃-modified bitumen at high temperature is smaller, nano-TiO₂/CaCO₃ is beneficial for bituminous pavement to resist high-temperature deformation.

Taking 60°C as the reference temperature, the complex shear modulus of base bitumen and nano-TiO₂/CaCO₃-modified bitumen is plotted in Figure 7. As shown, the complex modulus of base bitumen and nano-TiO₂/CaCO₃-modified bitumen is frequency-dependent, and their complex modulus increases with reduced frequency. At the same reduced frequency, the complex modulus of nano-TiO₂/CaCO₃-modified bitumen is higher. Moreover, the higher the frequency, the more significant their difference. Since the frequency relates to temperature, it also indicates that nano-TiO₂/CaCO₃ could boost the stabilization capability at higher temperature [52].

3.3.2. Rutting Factor (G^∗/sinδ) and Fatigue Factor (G^∗sinδ)

It is only one-sided to assess the properties of bitumen from the perspective of G^∗ or δ. If G^∗ is the same, their phase angle values may not be the same, and vice versa. Therefore, it needs to use different indicators to evaluate the performance of bitumen for various performances at different test temperatures.

Most studies have shown that the loss modulus (G″ = G^∗sinδ) has an important relationship with the fatigue characteristics of bitumen and bituminous mixtures. The larger the value of G^∗sinδ, the faster the energy loss under repeated loads and the lower the resistance to fatigue damage of bitumen and bituminous mixtures. Thus, G^∗sinδ is called the fatigue factor. On the other hand, G^∗/sinδ represents the rutting factor. Therefore, compared to static tests (such as penetration and softening point), dynamic tests have more intuitive and real advantages to evaluate the performances of bituminous binders.

Bituminous pavement is generally taken as 40°C∼80°C, and the rutting factor results of base bitumen and nano-TiO₂/CaCO₃-modified bitumen are plotted in Figure 8(a). As seen, the rutting factor of nano-TiO₂/CaCO₃-modified bitumen is larger by comparison at the same test temperature, which means that nano-TiO₂/CaCO₃-modified bitumen has a better high-temperature antirutting ability than base bitumen. Moreover, compared with base bitumen, the growth rate of rutting factor for nano-TiO₂/CaCO₃-modified bitumen changes from 5% to 13% when the test temperature increases from 40°C to 80°C [55].

(a)

(b)

Bituminous pavement usually services at a medium-temperature level. Therefore, bituminous materials need to have good antifatigue properties to maintain good working performance for a long period. As mentioned in the literature review, the smaller the fatigue factor, the better the fatigue resistance of bitumen. The fatigue factor results of base bitumen and nano-TiO₂/CaCO₃ modified bitumen are plotted in Figure 8(b). The fatigue factors of nano-TiO₂/CaCO₃-modified bitumen are lower to different degrees at 10°C∼30°C. This shows that nano-TiO₂/CaCO₃-modified bitumen also has good fatigue resistance properties at medium temperature. The energy loss of nano-TiO₂/CaCO₃-modified bitumen is slower under repeated loads, and it can continue to work for a longer time.

3.4. Beam Bending Rheometer Test

3.4.1. BBR Test Analysis

(1) Creep Characteristics. The creep deformations versus loading time at −18°C for base bitumen and nano-TiO₂/CaCO₃-modified bitumen were measured. The deflection-time curve reflects a typical viscoelastic behavior of bitumen in Figure 9. Nano-TiO₂/CaCO₃-modified bitumen and base bitumen have similar creep curves. Stage I: at the initial loading, these two kinds of bitumen have obvious elastic deformation, which characterizes the low-temperature elastic performances of bitumen. Stage II: within 50 s of loading, the deformation of bitumen gradually increases, and the growth rate of deformation gradually decreases. This is due to the combined effect of the viscous and elastic properties of bitumen. Stage III: from 50 s to the end of loading, the deformation of bitumen continues to increase, and the growth rate of deformation tends to be constant, representing the viscous nature of bitumen. Stage IV: after unloading, bitumen shows an instantaneous elastic recovery and a delayed elastic recovery.

Although the creep characteristics of base bitumen and nano-TiO₂/CaCO₃-modified bitumen are not essentially different, their proportion of viscoelastic components have been changed. Under the same constant load, the deformation of nano-TiO₂/CaCO₃-modified bitumen is smaller by comparison.

(2) Stiffness Modulus and m-Value. In SHRP specifications, modulus as well as its m-value is recommended as a basis for PG performance classification. The larger the corresponding creep stiffness modulus, that is, the smaller the creep deformation, the greater the stress required to produce unit strain, indicating that the bituminous material is harder. Figure 10 plots the creep stiffness modulus and m-value varying with time for base bitumen and nano-TiO₂/CaCO₃-modified bitumen. Creep stiffness modulus for base bitumen and nano-TiO₂/CaCO₃-modified bitumen decreases with time. However, the creep stiffness modulus of nano-TiO₂/CaCO₃-modified bitumen is larger by comparison and not more than 300 MPa, which meets the specification requirements. In Figure 10(b), the m-value of base bitumen and nano-TiO₂/CaCO₃-modified bitumen becomes larger as time goes on. The m-value at 60 s of nano-TiO₂/CaCO₃-modified bitumen is smaller, and the m-value is larger than or equal to 0.3, meeting the specification requirements. This is mainly because the light components in asphalt are absorbed by nanoparticles, which increases the relative proportion of heavy components and makes asphalt more hard and brittle [53]. Compared with base bitumen, nano-TiO₂/CaCO₃-modified bitumen has a larger modulus with a smaller m-value, representing that crack resistance for modified bitumen has been reduced slightly, but it can also meet the specification requirements.

(a)

(b)

3.4.2. Rheological Model of Bitumen

The modulus versus loading time can be fitted by taking the logarithm of stiffness modulus and time according to equation (6), and the SHRP models of base bitumen and nano-TiO₂/CaCO₃-modified bitumen are plotted in Figures 11(a) and 11(b), respectively. Although the accuracy of the fitting SHRP model is high, these fitted parameters do not have clear physical meaning, which could not reflect viscoelastic properties of bituminous materials.

(a)

(b)

Prior studies have noted the effectiveness of the Burgers model for bitumen [42]. The Burgers model of stiffness modulus of small bituminous binder beam was defined:

The Burgers model has been obtained by fitting the following equation (8), as shown in Figure 11. E₁ of nano-TiO₂/CaCO₃-modified bitumen is larger by comparison, which shows that the instant elastic deformation of modified bitumen is smaller compared with base bitumen. η₁ is the viscosity coefficient for permanent deformation, and a larger value of η₁ represents the smaller permanent deformation. η₁ of TiO₂/CaCO₃ nanoparticle-bitumen was slightly larger by comparison, which means that incorporation of nano-TiO₂/CaCO₃ increases the viscosity of bitumen and reduces its creep rate. In addition, E₂ is important for preventing the development of viscous element η₂, and these two parameters are mainly reflected in the initial stages of loading and unloading. In general, by comparing Figures 11(a) and 11(b), there is little difference for the stiffness modulus and m-value between base bitumen and nano-TiO₂/CaCO₃-modified bitumen. Nano-TiO₂/CaCO₃-modified bitumen has very slight changes in increasing stiffness modulus and reducing deformation. Therefore, the incorporation of nano-TiO₂/CaCO₃ has little effect on improving the anticracking property of bitumen at low temperature.

In addition, both the SHRP double logarithmic polynomial fitting model and the Burgers model have high accuracy and are very close to the measured stiffness modulus. However, compared with SHRP, fitting Burgers can reflect bituminous viscoelastic changes before and after nano-TiO₂/CaCO₃ modification, indicating a clearer physical meaning. Therefore, it is recommended to use the Burgers model to fit and analyze the BBR test.

4. Conclusions

Influences of TiO₂/CaCO₃ nanoparticles on bituminous conventional performances were analyzed. Moreover, the rotational viscosity test has been employed for discussing the influences of nano-TiO₂/CaCO₃ on temperature sensitivity of bitumen. Meanwhile, the DSR and BBR tests were also employed to analyze the low-medium-high-temperature performances of TiO₂/CaCO₃ nanoparticle-bitumen. The conclusions are drawn as follows:(1)Nano-TiO₂/CaCO₃ would enhance bituminous mechanical performances. As nano-TiO₂/CaCO₃ dosage increased, penetration and ductility of nano-TiO₂/CaCO₃-modified bitumen decreased, while softening point increased. When the nano-TiO₂/CaCO₃ dosage exceeded 5%, the growth rates of conventional test results have been slowed down. Based on the OD analysis, the reasonable dosage of nano-TiO₂/CaCO₃ was recommended as 5% by weight of base bitumen.(2)According to the analysis of rotational viscosity test, the addition of nano-TiO₂/CaCO₃ was beneficial to improve the viscosity and reduce bituminous sensitivity. Meanwhile, viscosity variation showed a significant increasing trend.(3)Nano-TiO₂/CaCO₃ can affect the G^∗ as well as δ but will not change its variation law with temperature. The addition of nano-TiO₂/CaCO₃ was beneficial to enhance the capacity of antirutting by increasing its rutting factor. The fatigue factor showed that TiO₂/CaCO₃ enhanced bituminous medium-temperature fatigue resistance.(4)The proportion of viscoelastic components of bitumen was changed by TiO₂/CaCO₃, which changed the elastic component and viscosity component. In addition, nano-TiO₂/CaCO₃-modified bitumen had a larger creep stiffness modulus and a smaller m-value compared with base bitumen. It showed that anticracking property of bitumen reduced slightly but could also comply with the specification.(5)The analysis results showed that nano-TiO₂/CaCO₃ could increase the stiffness modulus while increasing the viscosity of modified bitumen. Therefore, incorporating nano-TiO₂/CaCO₃ may weaken the low-temperature anticracking property of bitumen.

This study only evaluated the macroscopic properties of nano-TiO₂/CaCO₃-modified asphalt and did not conduct in-depth analysis from the aspect of microscopic mechanism, which is also the future direction of this research work.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon request.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

This research was funded by the Nanning Excellent Young Scientist Program (Grant no. RC20180108), Nanning Excellent Young Scientist Program and Guangxi Beibu Gulf Economic Zone Major Talent Program (Grant no. RC20190206), Science & Technology Base & Talent Special Project of Guangxi Province (Grant no. AD19245152), “Yongjiang Plan” of Nanning Leading Talents in Innovation and Entrepreneurship (Grant no. 2018-01-04), Scientific and Technological Project of Science and Technology Department of Jilin Province (Grant no. 20190303052SF), and the Innovation Special Project of Zhongshan Science and Technology Bureau (Grant no. 2019AG001).

References

T. Chen, Y. C. Luan, T. Ma et al., “Mechanical and microstructural characteristics of different interfaces in cold recycled mixture containing cement and asphalt emulsion,” Journal of Cleaner Production, vol. 258, 2020.
View at: Publisher Site | Google Scholar
X. H. Ding, T. Ma, L. H. Gu et al., “Investigation of surface micro-crack growth behavior of asphalt mortar based on the designed innovative mesoscopic test,” Materials & Design, vol. 185, 2020.
View at: Google Scholar
F. L. Tang, T. Ma, Y. S. Guan et al., “Parametric modeling and structure verification of asphalt pavement based on BIM-ABAQUS,” Automation in Construction, vol. 111, 2020.
View at: Publisher Site | Google Scholar
M. Guo, M. Liang, Y. Jiao, W. Zhao, Y. Duan, and H. Liu, “A review of phase change materials in asphalt binder and asphalt mixture,” Construction and Building Materials, vol. 258, Article ID 119565, 2020.
View at: Publisher Site | Google Scholar
M. Chen, B. Javilla, W. Hong et al., “Rheological and interaction analysis of asphalt binder, mastic and mortar,” Materials, vol. 12, no. 1, 2019.
View at: Publisher Site | Google Scholar
A. Behnood and M. Modiri Gharehveran, “Morphology, rheology, and physical properties of polymer-modified asphalt binders,” European Polymer Journal, vol. 112, pp. 766–791, 2019.
View at: Publisher Site | Google Scholar
Q. Guo, L. Li, Y. Cheng, Y. Jiao, and C. Xu, “Laboratory evaluation on performance of diatomite and glass fiber compound modified asphalt mixture,” Materials & Design (1980–2015), vol. 66, pp. 51–59, 2015.
View at: Publisher Site | Google Scholar
F. L. Tang, T. Ma, J. H. Zhang et al., “Integrating three-dimensional road design and pavement structure analysis based on BIM,” Automation in Construction, vol. 113, 2020.
View at: Publisher Site | Google Scholar
M. Guo, H. Q. Liu, Y. B. Jiao et al., “Effect of WMA-rap technology on pavement performance of asphalt mixture: a state-of-the-art review,” Journal of Cleaner Production, vol. 266, 2020.
View at: Publisher Site | Google Scholar
G. Tan, Z. Zhu, W. Wang et al., “Flexural ductility and crack-controlling capacity of polypropylene fiber reinforced ECC thin sheet with waste superfine river sand based on acoustic emission analysis,” Construction and Building Materials, vol. 277, 2021.
View at: Publisher Site | Google Scholar
Q. L. Guo, Q. Liu, P. Zhang et al., “Temperature and pressure dependent behaviors of moisture diffusion in dense asphalt mixture,” Construction and Building Materials, vol. 246, 2020.
View at: Publisher Site | Google Scholar
Y. Jiao, L. Fu, W. Shan, and S. Liu, “Damage fracture characterization of pervious asphalt considering temperature effect based on acoustic emission parameters,” Engineering Fracture Mechanics, vol. 210, pp. 147–159, 2019.
View at: Publisher Site | Google Scholar
H. Xu, W. Guo, and Y. Tan, “Permeability of asphalt mixtures exposed to freeze-thaw cycles,” Cold Regions Science and Technology, vol. 123, pp. 99–106, 2016.
View at: Publisher Site | Google Scholar
J. P. Bilodeau, J. Y. Yi, and P. M. Thiam, “Surface deflection analysis of flexible pavement with respect to frost penetration,” Journal of Cold Regions Engineering, vol. 33, no. 4, 2019.
View at: Publisher Site | Google Scholar
L. Garcia-Gil, R. Miró, and F. E. Pérez-Jiménez, “New approach to characterize cracking resistance of asphalt binders,” Construction and Building Materials, vol. 166, pp. 50–58, 2018.
View at: Publisher Site | Google Scholar
Q. L. Guo, H. Y. Wang, Y. Gao et al., “Investigation of the low-temperature properties and cracking resistance of fiber-reinforced asphalt concrete using the dic technique,” Engineering Fracture Mechanics, vol. 229, 2020.
View at: Google Scholar
Q. Guo, G. Li, Y. Gao et al., “Experimental investigation on bonding property of asphalt-aggregate interface under the actions of salt immersion and freeze-thaw cycles,” Construction and Building Materials, vol. 206, pp. 590–599, 2019.
View at: Publisher Site | Google Scholar
G. J. Tan, W. S. Wang, Y. C. Cheng et al., “Establishment of complex modulus master curves based on generalized sigmoidal model for freeze-thaw resistance evaluation of basalt fiber-modified asphalt mixtures,” Polymers, vol. 12, no. 8, 2020.
View at: Publisher Site | Google Scholar
F. Saeed, M. Rahman, D. Chamberlain, and P. Collins, “Asphalt surface damage due to combined action of water and dynamic loading,” Construction and Building Materials, vol. 196, pp. 530–538, 2019.
View at: Publisher Site | Google Scholar
L. Brasileiro, F. Moreno-Navarro, R. Tauste-Martinez et al., “Reclaimed polymers as asphalt binder modifiers for more sustainable roads: a review,” Sustainability, vol. 11, no. 3, 2019.
View at: Publisher Site | Google Scholar
W. S. Wang, Y. C. Cheng, H. P. Chen et al., “Study on the performances of waste crumb rubber modified asphalt mixture with eco-friendly diatomite and basalt fiber,” Sustainability, vol. 11, no. 19, 2019.
View at: Publisher Site | Google Scholar
W. S. Wang, Y. C. Cheng, and G. J. Tan, “Design optimization of SBS-modified asphalt mixture reinforced with eco-friendly basalt fiber based on response surface methodology,” Materials, vol. 11, no. 8, 2018.
View at: Publisher Site | Google Scholar
Z. B. Ren, Y. Q. Zhu, Q. Wu et al., “Enhanced storage stability of different polymer modified asphalt binders through nano-montmorillonite modification,” Nanomaterials, vol. 10, no. 4, 2020.
View at: Publisher Site | Google Scholar
H. N. Yu, W. Dai, G. P. Qian et al., “The nox degradation performance of nano-TiO₂ coating for asphalt pavement,” Nanomaterials, vol. 10, no. 5, 2020.
View at: Publisher Site | Google Scholar
S. G. Jahromi and A. Khodaii, “Effects of nanoclay on rheological properties of bitumen binder,” Construction and Building Materials, vol. 23, no. 8, pp. 2894–2904, 2009.
View at: Publisher Site | Google Scholar
M. Abdelrahman, D. R. Katti, A. Ghavibazoo et al., “Engineering physical properties of asphalt binders through nanoclay-asphalt interactions,” Journal of Materials in Civil Engineering, vol. 26, no. 12, 2014.
View at: Publisher Site | Google Scholar
Z. You, J. Mills-Beale, J. M. Foley et al., “Nanoclay-modified asphalt materials: preparation and characterization,” Construction and Building Materials, vol. 25, no. 2, pp. 1072–1078, 2011.
View at: Publisher Site | Google Scholar
M. J. Khattak, A. Khattab, H. R. Rizvi, and P. Zhang, “The impact of carbon nano-fiber modification on asphalt binder rheology,” Construction and Building Materials, vol. 30, pp. 257–264, 2012.
View at: Publisher Site | Google Scholar
M. Chen and Y. H. Liu, “Nox removal from vehicle emissions by functionality surface of asphalt road,” Journal of Hazardous Materials, vol. 174, no. 1–3, pp. 375–379, 2010.
View at: Publisher Site | Google Scholar
H. Yao, Z. You, L. Li et al., “Rheological properties and chemical bonding of asphalt modified with nanosilica,” Journal of Materials in Civil Engineering, vol. 25, no. 11, pp. 1619–1630, 2013.
View at: Publisher Site | Google Scholar
N. I. M. Yusoff, A. A. S. Breem, H. N. M. Alattug, A. Hamim, and J. Ahmad, “The effects of moisture susceptibility and ageing conditions on nano-silica/polymer-modified asphalt mixtures,” Construction and Building Materials, vol. 72, pp. 139–147, 2014.
View at: Publisher Site | Google Scholar
S. Tayfur, H. Ozen, and A. Aksoy, “Investigation of rutting performance of asphalt mixtures containing polymer modifiers,” Construction and Building Materials, vol. 21, no. 2, pp. 328–337, 2007.
View at: Publisher Site | Google Scholar
H. Wang, Z. You, J. Mills-Beale, and P. Hao, “Laboratory evaluation on high temperature viscosity and low temperature stiffness of asphalt binder with high percent scrap tire rubber,” Construction and Building Materials, vol. 26, no. 1, pp. 583–590, 2012.
View at: Publisher Site | Google Scholar
H. Zhu and L. Sun, “A viscoelastic-viscoplastic damage constitutive model for asphalt mixtures based on thermodynamics,” International Journal of Plasticity, vol. 40, pp. 81–100, 2013.
View at: Publisher Site | Google Scholar
X. Ma, H. Chen, G. Cao, M. Xing, and D. Niu, “Investigation of viscoelastoplastic behavior of asphalt mastic: effects of shear strain rate and filler volume fraction,” Construction and Building Materials, vol. 200, pp. 559–569, 2019.
View at: Publisher Site | Google Scholar
M. Guo, Y. Tan, and S. Zhou, “Multiscale test research on interfacial adhesion property of cold mix asphalt,” Construction and Building Materials, vol. 68, pp. 769–776, 2014.
View at: Publisher Site | Google Scholar
J. Q. Zhu, T. Ma, J. W. Fan et al., “Experimental study of high modulus asphalt mixture containing reclaimed asphalt pavement,” Journal of Cleaner Production, vol. 263, 2020.
View at: Publisher Site | Google Scholar
K. Chung, S. Lee, M. Park, P. Yoo, and Y. Hong, “Preparation and characterization of microcapsule-containing self-healing asphalt,” Journal of Industrial and Engineering Chemistry, vol. 29, pp. 330–337, 2015.
View at: Publisher Site | Google Scholar
X. Zhou, B. Ma, K. Wei et al., “Preparation of shape memory epoxy resin for asphalt mixtures and its influences on the main pavement performance,” Construction and Building Materials, vol. 267, Article ID 121055, 2020.
View at: Publisher Site | Google Scholar
H. Liu and R. Luo, “Development of master curve models complying with linear viscoelastic theory for complex moduli of asphalt mixtures with improved accuracy,” Construction and Building Materials, vol. 152, pp. 259–268, 2017.
View at: Publisher Site | Google Scholar
M. Lagos-Varas, D. Movilla-Quesada, J. P. Arenas et al., “Study of the mechanical behavior of asphalt mixtures using fractional rheology to model their viscoelasticity,” Construction and Building Materials, vol. 200, pp. 124–134, 2019.
View at: Publisher Site | Google Scholar
W. S. Wang, G. J. Tan, C. Y. Liang et al., “Study on viscoelastic properties of asphalt mixtures incorporating SBS polymer and basalt fiber under freeze-thaw cycles,” Polymers, vol. 12, no. 8, 2020.
View at: Publisher Site | Google Scholar
T. Ma, H. Wang, D. Zhang, and Y. Zhang, “Heterogeneity effect of mechanical property on creep behavior of asphalt mixture based on micromechanical modeling and virtual creep test,” Mechanics of Materials, vol. 104, pp. 49–59, 2017.
View at: Publisher Site | Google Scholar
M. K. Darabi, C.-W. Huang, M. Bazzaz, E. A. Masad, and D. N. Little, “Characterization and validation of the nonlinear viscoelastic-viscoplastic with hardening-relaxation constitutive relationship for asphalt mixtures,” Construction and Building Materials, vol. 216, pp. 648–660, 2019.
View at: Publisher Site | Google Scholar
Y. Gong, H. Bi, Z. Tian, and G. Tan, “Pavement performance investigation of nano-TiO₂/CaCO₃ and basalt fiber composite modified asphalt mixture under freeze‒thaw cycles,” Applied Sciences, vol. 8, no. 12, p. 2581, 2018.
View at: Publisher Site | Google Scholar
W. Wang, Y. Cheng, G. Tan, and C. Shi, “Pavement performance evaluation of asphalt mixtures containing oil shale waste,” Road Materials and Pavement Design, vol. 21, no. 1, pp. 179–200, 2020.
View at: Publisher Site | Google Scholar
L. Sun, X. Xin, and J. Ren, “Asphalt modification using nano-materials and polymers composite considering high and low temperature performance,” Construction and Building Materials, vol. 133, pp. 358–366, 2017.
View at: Publisher Site | Google Scholar
W. Wang, Y. Cheng, G. Tan, Z. Liu, and C. Shi, “Laboratory investigation on high- and low-temperature performances of asphalt mastics modified by waste oil shale ash,” Journal of Material Cycles and Waste Management, vol. 20, no. 3, pp. 1710–1723, 2018.
View at: Publisher Site | Google Scholar
Y. C. Cheng, W. S. Wang, G. J. Tan et al., “Assessing high- and low-temperature properties of asphalt pavements incorporating waste oil shale as an alternative material in Jilin province, China,” Sustainability, vol. 10, no. 7, 2018.
View at: Publisher Site | Google Scholar
Y. Zhang, T. Ma, M. Ling et al., “Predicting dynamic shear modulus of asphalt mastics using discretized-element simulation and reinforcement mechanisms,” Journal of Materials in Civil Engineering, vol. 31, no. 8, 2019.
View at: Publisher Site | Google Scholar
G. J. Tan, W. S. Wang, Y. C. Cheng et al., “Master curve establishment and complex modulus evaluation of SBS-modified asphalt mixture reinforced with basalt fiber based on generalized sigmoidal model,” Polymers, vol. 12, no. 7, 2020.
View at: Publisher Site | Google Scholar
C. Wu, L. Li, W. Wang et al., “Experimental characterization of viscoelastic behaviors of nano-tio2/caco3 modified asphalt and asphalt mixture,” Nanomaterials (Basel), vol. 11, no. 1, 2021.
View at: Publisher Site | Google Scholar
Y. C. Cheng, H. P. Bi, G. R. Ma et al., “Pavement performance of nano materials-basalt fiber compound modified asphalt binder,” Journal of Jilin University (Engineering and Technology Edition), vol. 2, pp. 460–465, 2018.
View at: Google Scholar
I. R. Segundo, S. Landi, A. Margaritis et al., “Physicochemical and rheological properties of a transparent asphalt binder modified with nano-TiO₂,” Nanomaterials, vol. 10, no. 11, p. 2152, 2020.
View at: Publisher Site | Google Scholar
G. Qian, H. Yu, X. Gong, and L. Zhao, “Impact of nano-TiO₂ on the No₂ degradation and rheological performance of asphalt pavement,” Construction and Building Materials, vol. 218, pp. 53–63, 2019.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2021 Liming Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

1022

Downloads

891

Citations

Advances in Materials Science and Engineering

High-Performance Materials and Advanced Characterization Methods for Durable Pavement

Laboratory Evaluation of Rheological Properties of Asphalt Binder Modified by Nano-TiO2/CaCO3

Abstract

1. Introduction

2. Experimental Materials and Methods

2.1. Materials and Tested Specimens

2.1.1. Base Bitumen

2.1.2. Nano-TiO2/CaCO3

2.1.3. TiO2/CaCO3 Nanoparticle-Bitumen

2.2. Laboratory Tests of Bitumen

2.2.1. Conventional Tests of Bitumen

2.2.2. Rotational Viscosity Test

2.2.3. Dynamic Shear Rheometer Test

2.2.4. Beam Bending Rheometer Test

3. Results and Discussion

3.1. Optimum Content of Nano-TiO2/CaCO3

3.1.1. Conventional Tests of Nano-TiO2/CaCO3-Modified Bitumen

3.1.2. Technical Indicators of TiO2/CaCO3 Nanoparticle-Bitumen

3.2. Rotational Viscosity Test

3.3. Dynamic Shear Rheometer Test

3.3.1. Complex Shear Modulus (G∗) and Phase Angle (δ)

3.3.2. Rutting Factor (G∗/sinδ) and Fatigue Factor (G∗sinδ)

3.4. Beam Bending Rheometer Test

3.4.1. BBR Test Analysis

3.4.2. Rheological Model of Bitumen

4. Conclusions

Data Availability

Conflicts of Interest

Acknowledgments

References

Copyright

Laboratory Evaluation of Rheological Properties of Asphalt Binder Modified by Nano-TiO₂/CaCO₃

2.1.2. Nano-TiO₂/CaCO₃

2.1.3. TiO₂/CaCO₃ Nanoparticle-Bitumen

3.1. Optimum Content of Nano-TiO₂/CaCO₃

3.1.1. Conventional Tests of Nano-TiO₂/CaCO₃-Modified Bitumen

3.1.2. Technical Indicators of TiO₂/CaCO₃ Nanoparticle-Bitumen

3.3.1. Complex Shear Modulus (G^∗) and Phase Angle (δ)

3.3.2. Rutting Factor (G^∗/sinδ) and Fatigue Factor (G^∗sinδ)