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Article

Revolutionizing Roadways: High-Performance Warm Mix Asphalt Binder with Trinidad Lake Asphalt and Recycled Tire Rubber

by
Shyaamkrishnan Vigneswaran
1,
Jihyeon Yun
1,
Moon-Sup Lee
2,*,
Kyu-Dong Jeong
2 and
Soon-Jae Lee
1
1
Department of Engineering Technology, Texas State University, San Marcos, TX 78666, USA
2
Korea Institute of Civil Engineering and Building Technology, Goyang-si 10223, Republic of Korea
*
Author to whom correspondence should be addressed.
Appl. Sci. 2024, 14(16), 7211; https://doi.org/10.3390/app14167211
Submission received: 19 July 2024 / Revised: 12 August 2024 / Accepted: 13 August 2024 / Published: 16 August 2024
Browse Figures
Versions Notes

Abstract

:
This study investigates the transformative effects of incorporating Trinidad Lake asphalt (TLA), crumb rubber modifier (CRM), and the warm mix additive leadcap (LC) into petroleum-based asphalt binder PG 64-22. Our results show that LC significantly reduces binder viscosity, leading to easier application and lower energy consumption, especially when combined with TLA and CRM. The addition of TLA and CRM enhances rutting resistance, with notable improvements in both pre- and post-aging conditions, particularly in formulations combining PG 64-22, 20% TLA, and 10% CRM. These formulations exhibit superior performance metrics, such as increased percentage recovery (% rec) and reduced non-recoverable creep compliance (Jnr), indicating improved flexibility and deformation resistance. Furthermore, LC balances increased rigidity and susceptibility to fatigue cracking from higher TLA and CRM levels, respectively. These modifications also promote environmental sustainability by reducing energy usage and emissions during production and paving. This study highlights LC’s critical role in advancing high-performance, eco-friendly warm mix asphalt binders, offering valuable insights for sustainable pavement engineering and setting a new benchmark for advanced asphalt technologies.

1. Introduction

Asphalt, though comprising only about five percent of the road mixture, plays a crucial role in the performance of roads. However, pure asphalt often fails to meet the demanding performance criteria required to resist high-temperature flow and prevent low-temperature cracking. This inadequacy is largely due to increasing traffic volumes, heavier loads, and more severe weather conditions. To address these challenges, asphalt is fortified with various additives to enhance its resistance to temperature fluctuations and repetitive heavy traffic loads [1].
In recent years, the use of modified binders has gained significant traction. This trend is driven by the strong inclination of public agencies to invest in durable pavement solutions, the increasing demand for high-performance hot-mix asphalt (HMA) pavements, and the adoption of Superpave asphalt binder standards in response to economic and environmental concerns [2,3,4,5]. One promising additive for asphalt modification is Trinidad Lake asphalt (TLA). TLA is known for its reliable characteristics, dense composition, and exceptional rheological qualities. It consists mainly of soluble bitumen, mineral matter, and various minor constituents [6,7]. TLA exhibits a high softening point, minimal penetration, excellent thermal stability, and exceptional chemical stability. Additionally, TLA offers excellent adhesive properties and remarkable stability, making it compatible with petroleum asphalt due to their similar chemical compositions. TLA-modified binders exhibit enhanced durability, reduced sensitivity to temperature fluctuations and permanent deformation, improved resistance to aging, high rigidity, lower solvent solubility, and minimal phase separation [8,9,10]. However, higher rigidity can reduce workability, pose compaction challenges, and lead to potential premature field failure, negatively impacting pavement performance [7].
Studies on the rheological properties of TLA-modified binders have shown that their varied chemical components and colloid matrix result in different levels of compatibility, leading to diverse performance outcomes [11,12]. Increasing TLA replacement percentage can enhance pavement stiffness which only reduces life span of the pavement [10]. To address the stiffness issue, crumb rubber, derived from end-of-life tires (ELTs), is employed as a modifier. Crumb rubber has been used since the early 1960s to improve pavement performance by reducing stiffness [13,14,15]. However, adding a significant amount of crumb rubber to an asphalt concrete mixture can increase its viscosity, complicating the laying and compaction processes, and impacting pavement resilience [16,17]. To mitigate high viscosity, this study employed WMA-LEADCAP (WMA-LC) and untreated crumb rubber with a particle size of ≤0.5 mm. Extended blending times can significantly affect pavement performance, so the blending duration was limited to 30 min. Previous research has shown that LC, which utilizes special chemicals, effectively lowers the temperatures required for mixing and compacting asphalt mixes. The addition of LC also significantly reduces the stiffness and viscosity of the modified binder, as noted in previous studies [18,19,20,21]. This reduction in stiffness and viscosity not only improves working conditions by lowering pollutants in asphalt fields but also offers numerous advantages. These benefits include reduced fuel consumption, extended paving durations, and increased hauling distances. Additionally, the technology allows for early traffic openings, minimizes binder aging, and decreases the likelihood of cracking [22].
The main objective of this study is to produce high-performance warm mix asphalt by incorporating crumb rubber modifier (CRM) and Trinidad Lake asphalt (TLA). The approach involves gradually increasing CRM concentration by 5% with each iteration, reaching a maximum of 10% to reduce viscosity. Simultaneously, TLA substitution is capped at an upper limit of 20%, at increments of 10%, to optimize the asphalt blend and enhance performance, as increased TLA replacement percentage increases pavement stiffness [10]. To ensure consistent blending, the wet method is employed, following McDonald’s technology [23]. Figure 1 in the document illustrates the experimental setup used in this investigation. By systematically adjusting CRM and TLA concentrations, this study aims to develop a high-performance warm mix asphalt binder that meets desired specifications.

2. Experimental Design

2.1. Materials

To enhance the performance of warm mix asphalt (WMA) utilizing Trinidad Lake asphalt (TLA) and crumb rubber modifier (CRM), PG 64-22 asphalt binder was selected as the foundational binder. PG 64-22 is known for its robust performance metrics, which are critical in formulations involving multiple modifiers like TLA and CRM. Table 1 below presents the properties of the original asphalt binder, providing a baseline for understanding the impact of the modifications. TLA, in its natural form, serves as the second modifier, comprising bituminous material and mineral components in stable proportions. TLA’s composition includes approximately 53% to 55% bitumen, 36% to 37.7% minerals, 4.3% hydrated mineral water, and 3.2% other organic matter, detailed in Table 2. The third modifier, untreated CRM, is room-temperature ground, renowned for its high resistance to rutting and cracking. WMA-Leadcap-64, another modifier, is a blend of crystal controller and wax crystals, with additional details available in Table 3, Table 4 and Table 5. Superpave test specifications guided experiments to evaluate the extended durability of the modified binder.

2.2. Production and Sampling of TLA Modified Rubberized Binders

The study utilizes a standard asphalt binder with a performance grade of PG 64-22 as the base material. The binder is modified by incorporating Trinidad Lake asphalt (TLA) at two precise proportions: 10% and 20% by weight of the original binder. The modification process begins by manually combining ingredients to achieve a visually consistent mixture. To ensure thorough dispersion and incorporation of TLA into the underlying binder, the mixing temperature is maintained above 150 °C. A low-shear mixer is utilized at a temperature of 177 °C.
Currently, CRM is incorporated in two specific proportions: 5% and 10% relative to the weight of the original binder. Afterwards, the mixture is stirred at a shear rate of 700 revolutions per minute. Additionally, 1.5% LC is introduced and stirred for a period of 30 min, with the temperature carefully maintained at a constant 177 °C. This ensures a consistently modified binder and improves the efficient incorporation of CRM and LC into the TLA binder matrix.
Following the modification process, a segment of the binder is subjected to rotational viscosity testing and viscoelastic tests. The evaluations are conducted using established protocols, which involve the use of the direct shear rheometer (DSR) to perform initial binder tests and multiple stress creep recovery (MSCR) tests. These tests are essential for assessing the modified binder’s deformation and flow characteristics under various stress conditions.
To simulate the impacts of short-term aging, the binder undergoes the rolling thin film oven (RTFO) test for 85 min at a temperature of 163 °C, in accordance with the specifications provided in ASTM D 2872 [28] standards. Afterwards, samples of materials that have undergone rolling thin film oven (RTFO) aging are analyzed using the dynamic shear rheometer (DSR) to ascertain their viscoelastic properties. In addition, these samples are subjected to additional testing using the multiple stress creep recovery (MSCR) method. This step replicates the natural deterioration that takes place during the production and building of hot-mix asphalt pavement.
In order to replicate the impacts of extended exposure to field conditions, the binder is subjected to the pressure aging vessel (PAV) test for a period of 20 h at a temperature of 100 °C, as specified by the guidelines outlined in ASTM D 6251 [29]. Following the aging process, PAV residue samples are analyzed at a temperature of 25 °C using the dynamic shear rheometer (DSR) and at a temperature of −12 °C using the bending beam rheometer (BBR) in accordance with the guidelines outlined in AASHTO T 313 [30]. These tests provide valuable data on the binder’s capacity to withstand prolonged environmental conditions, such as temperature fluctuations and oxidative aging.
This study employs a multi-stage approach to produce and evaluate TLA-modified rubberized binders, offering detailed analysis of their thermo-mechanical properties and aging behavior.

2.3. Evaluation of Binder

2.3.1. Superpave Binder Testing

Assessing the effectiveness of asphalt binders at different stages of their lifespan is crucial for guaranteeing the strength and longevity of road constructions. An extensive examination was conducted using three standardized test methods recommended by the American Association of State Highway and Transportation Officials (AASHTO): the viscosity test (AASHTO T 316) [31], the dynamic shear rheometer (DSR) test (AASHTO T 315) [32], and the bending beam rheometer (BBR) test (AASHTO T 313) [30].
The Brookfield Rotational Viscometer was used to perform rheological evaluation through a viscosity test. Viscosity measurements were conducted on a standardized 10.5 g sample of each modified binder type using a number 27 spindle. Tests were conducted at two different temperatures, 135 °C and 180 °C, in order to encompass a variety of conditions that binders might face. This technique offers crucial insights into the fluidic properties of binders, which are vital for achieving optimal mixing and compaction procedures in construction. This ensures the appropriate workability and consistency of the asphalt mixture.
The purpose of the DSR test was to measure the viscoelastic properties of the binders in their original state and after undergoing two aging processes: short-term aging (RTFO) and long-term aging (RTFO + PAV). The test was performed at a frequency of 10 radians per second (approximately 1.59 Hz), which is considered optimal for accurately representing the shear-related behaviors of the material in real-world conditions. The complex shear modulus (G*) and phase angle (δ) were calculated. The parameter G*/sin δ was specifically derived to evaluate the material’s ability to withstand rutting, indicating the binder’s capacity to resist permanent deformation when subjected to a load. On the other hand, the measurement of G*·sin δ at 25 °C was conducted to assess the likelihood of fatigue cracking, a crucial factor in determining the binder’s ability to withstand repeated traffic loading.
The BBR test aimed to assess the cold temperature performance of the binders by utilizing the residual samples from the RTFO + PAV process. Creep stiffness (S) measurements were conducted on modified binder beams with dimensions of 125 × 6.35 × 12.7 mm at a temperature of −12 °C to replicate cold-weather conditions. A load of 100 g was exerted, and the displacement at the center of the beam was observed for a duration of 60 s. This test is essential for evaluating the binder’s response to thermally induced stresses, particularly its vulnerability to cracking, which can have a significant impact on pavement durability in cold climates.
The tests were performed three times each, and the average of the results was calculated to ensure statistical robustness and reliability. This versatile evaluation methodology facilitated a thorough comprehension of the performance attributes of asphalt binders throughout different stages of their lifespan, establishing a strong basis for forecasting the long-term performance of pavements and guiding the selection of materials and mix design.

2.3.2. Multiple Stress Creep Recover (MSCR) Test

The MSCR test is a technique employed to quantify the recuperation of various strains in a pavement material. The MSCR test is conducted on modified asphalt binder using DSR equipment, following the AASHTO TP 70 guidelines [33]. The rheological characteristics of the binder are assessed by performing this test on both the unaged and short-term aged RTFO samples. The MSCR test is performed at two separate stress levels, namely 0.1 kPa and 3.2 kPa. This process entails subjecting the material to repetitive cycles of creep loading and unloading, with durations of 1 s and 9 s, respectively. Every stress level undergoes a total of ten cycles.
The test yields two essential parameters: the nonrecoverable creep compliance (Jnr) and the percentage recovery (% rec). These measurements serve as quantitative tools for evaluating the susceptibility of asphalt binders to rutting. The nonrecoverable creep compliance (Jnr) is calculated by dividing the nonrecoverable shear strain by the applied shear stress. Jnr is a parameter that measures a material’s ability to resist permanent deformation, specifically called rutting, when exposed to repeated traffic loads. A higher value of Jnr typically indicates a material that is more susceptible to rutting, which is a crucial factor to consider when choosing materials for road construction.

2.4. Statistical Analysis Method

We utilized the Statistical Package for the Social Sciences (SPSS) to conduct an analysis of variance (ANOVA), followed by Fisher’s least significant difference (LSD) test. Both analyses were performed with a significance level set at α = 0.05. The primary objective of employing ANOVA was to determine if there were statistically significant differences among the means of the samples. A critical significance level of 0.05 indicates that we accept a 5% risk of mistakenly concluding that there is a difference when there is none (Type I error).
After identifying significant differences with ANOVA, Fisher’s LSD test was applied to gain a deeper understanding of which specific groups exhibited these differences. Fisher’s LSD method calculates the smallest difference between the means of two samples required to assert that the population means are statistically distinct at the specified significance level. The LSD serves as a benchmark, and if the absolute difference between any two-sample means meets or exceeds this threshold, it indicates that the population means are statistically distinct.
To clarify further, the notion of a “95% probability of each finding being accurate” can be misleading. A significance level of 0.05 means that if the null hypothesis is true (i.e., no real differences exist between groups), there is a 5% chance of observing the data or more extreme results. Thus, rejecting the null hypothesis is done with 95% confidence, not a 95% “probability of being true”.
ANOVA was employed as an initial screening method to identify any significant differences in the sample means among groups. Upon obtaining a significant ANOVA result, Fisher’s least significant difference test was used for pairwise comparisons to evaluate differences in population means among specific groups [34].

3. Results and Discussion

3.1. Rotational Viscosity

Figure 2 and Table 5 and Table 6 assess the viscosity of modified asphalt binders at 135 °C and 180 °C, focusing on the use of the warm mix additive LC for high-performance applications in pavement engineering. Warm mix asphalt technologies, incorporating additives like LC, aim to lower production and compaction temperatures, offering advantages such as reduced energy use, lower emissions, and improved workability.
The base binder, PG 64-22, has viscosities of 755 cP at 135 °C and 285 cP at 180 °C, serving as benchmarks for modification effects. Adding TLA and CRM increases viscosity, enhancing high-temperature performance but also requiring more energy for mixing and compaction. For example, 10% TLA raises viscosities to 858 cP and 300 cP, while 20% TLA results in 865 cP and 310 cP at 135 °C and 180 °C, respectively. CRM has a more pronounced impact, with 5% CRM increasing viscosities to 1148 cP and 298 cP, and 10% CRM to 2550 cP and 685 cP.
Adding LC to binders with TLA and CRM generally reduces viscosity. For instance, 10% TLA with 5% CRM and 1.5% LC results in viscosities of 1125 cP at 135 °C and 287.5 cP at 180 °C, compared to 1275 cP and 375 cP without LC. With 20% TLA, 5% CRM, and 1.5% LC, viscosities are 1450 cP and 537.5 cP, versus 1562.5 cP and 500 cP without LC. The viscosity reduction, especially at 180 °C, highlights LC’s effectiveness in improving binder workability at high temperatures.
LC decreases binder viscosity, enhancing workability during mixing and compaction, and reducing energy requirements. Despite lower viscosities, LC-containing binders maintain high performance, with sufficient rigidity to resist deformation at elevated temperatures. This balance underscores LC’s role in producing high-performance warm mix binders, aligning with warm mix asphalt goals of energy efficiency and reduced emissions.

3.2. Rutting Property (G*/sin δ )

Figure 3 and Table 7 and Table 8 present the rutting resistance G*/sin δ in kPa for various binder samples before (original) and after (RTFO) short-term aging. The tested binders include a base binder (PG 64-22), TLA, CRM, and the warm mix additive (LC), offering insights into the improved rutting resistance achieved by LC.
The initial rutting resistance of the base binder (PG 64-22) is 2.01 kPa, increasing to 5.25 kPa after RTFO aging. Adding TLA enhances rutting resistance slightly: PG 64-22 with 10% TLA shows 2.51 kPa before and 5.88 kPa after aging. With 20% TLA, resistance improves to 3.07 kPa and 6.47 kPa, respectively, demonstrating TLA’s positive impact on binder performance.
CRM significantly boosts rutting resistance. For instance, PG 64-22 with 5% CRM achieves 3.71 kPa pre-aging and 8.10 kPa post-aging, with increasing CRM content further enhancing performance. The most significant improvements occur with LC addition. For example, PG 64-22 combined with 10% TLA, 5% CRM, and 1.5% LC shows resistance of 4.30 kPa before and 7.50 kPa after aging, highlighting LC’s substantial effect.
LC dramatically improves binder performance under high temperatures and stress. Using PG 64-22 with 10% TLA, 10% CRM, and 1.5% LC, rutting resistance increases from 8.58 kPa to 14.20 kPa post-aging. The most significant enhancement is in the PG 64-22 + 20% TLA + 10% CRM + 1.5% LC mixture, with values of 9.67 kPa pre-aging and 20.60 kPa post-aging, demonstrating that increased TLA and CRM with LC significantly improve rutting resistance. LC’s role in producing high-performance warm mix binders is clear.
LC conserves energy and reduces emissions during pavement construction, enabling work at lower temperatures while maintaining sufficient compression. It enhances binder rheology, increasing resistance to deformation, crucial for high-temperature applications prone to rutting. The synergy of CRM and LC combines flexibility and resilience with enhanced rigidity, yielding a binder performing well under high temperatures and heavy loads. RTFO test results show binders with LC resist rutting even after aging, vital for long-term pavement performance.
Overall, incorporating LC with TLA and CRM substantially improves binder rutting resistance, both before and after short-term aging, demonstrating LC’s efficacy in producing high-performance warm mix binders for challenging conditions.

3.3. Multiple Stress Creep Recovery (MSCR) Test

% Recovery and Jnr Condition for Both Original and RTFO Condition

Figure 4 and Table 9 and Table 10 present the performance metrics for various binder modifications, focusing on percentage recovery and Jnr (k/Pa) before and after short-term aging (RTFO). Percentage recovery measures the binder’s elasticity and resilience, while Jnr assesses its non-recoverable creep compliance, with lower values indicating greater resistance to permanent deformation.
The original binder, PG 64-22, shows low percentage recovery (0.05% original, 1.86% RTFO) and high Jnr values (5.10 k/Pa original, 1.90 k/Pa RTFO), indicating inadequate elastic recovery and a tendency toward permanent deformation. Modifications with TLA show improvement, with 10% and 20% TLA increasing % recovery (0.39% to 0.67% original, 2.38% to 2.86% RTFO) and decreasing Jnr (4.22 k/Pa to 1.64 k/Pa original, 3.43 k/Pa to 1.45 k/Pa RTFO), suggesting enhanced elasticity and reduced deformation. However, recovery percentages remain lower compared to advanced modifications.
Adding 5% CRM significantly boosts % recovery (2.05% to 13.01% RTFO) and reduces Jnr (2.81 k/Pa to 0.95 k/Pa RTFO), indicating improved performance. When combined with LC, these metrics further improve, underscoring the additive’s positive impact. For example, with 10% TLA and 5% CRM plus LC, % recovery reaches 3.23% in the original and 13.69% in the RTFO, with Jnr values of 1.99 k/Pa for the original and 0.80 k/Pa for the RTFO. The modification with 20% TLA and 10% CRM shows exceptional performance, achieving 10.67% recovery original and 41.75% RTFO, with Jnr at 0.95 k/Pa original and 0.30 k/Pa RTFO. Inclusion of LC further enhances performance, with 8.80% recovery original and 43.49% RTFO, and Jnr at 0.85 k/Pa original and 0.42 k/Pa RTFO.
This signifies LC is an effective additive for warm mix, enhancing binder performance by increasing % recovery and reducing Jnr, thus improving elasticity and minimizing deformation, even under aging conditions. The synergistic effects of LC with TLA and CRM produce high-performance binders, with the 20% TLA + 10% CRM + 1.5% LC modification demonstrating superior performance, highlighting LC’s crucial role in creating durable high performance warm mix asphalt binders.

3.4. Fatigue Cracking Property (Intermediate Failure)

Figure 5 and Table 11 depict the G*sin δ values (kPa) for different compositions of PG 64-22 asphalt binder that have been modified with TLA, CRM, and LC. The G*sin δ parameter plays a critical role in evaluating the susceptibility of asphalt binders to fatigue cracking. Higher values of this parameter indicate a higher probability of such cracking, which can significantly reduce the durability of pavements.
When using the PG 64-22 base binder, we measure a G*sin δ value of 3400 kPa. This serves as a standard against which the effects of different modifications can be compared. When 10% TLA is added to PG 64-22, the G*sin δ value increases to 5695 kPa. Increasing the TLA content to 20% further raises the value to 6550 kPa. The substantial increase demonstrates that while TLA improves the rigidity of the binder, it also elevates the likelihood of fatigue cracking. The inclusion of CRM also affects the characteristics of the binder. An example is when PG 64-22 is combined with 10% TLA and 5% CRM, resulting in a G*sin δ value of 7910 kPa, which is very high. While this formulation enhances performance, the significant rise in stiffness suggests a greater susceptibility to fatigue cracking. Moreover, when PG 64-22, 20% TLA, and 5% CRM are combined, the resulting G*sin δ value is 5915 kPa, highlighting the significant increase in stiffness.
The significance of LC in these formulations is particularly notable. LC is an asphalt additive that is specifically created to decrease the viscosity of the binder at lower temperatures. This makes it easier to mix and compact the asphalt during construction. The inclusion of LC consistently decreases the G*sin δ values in different formulations, suggesting a positive impact on the rigidity of the binder. For instance, when PG 64-22 is combined with 10% TLA, 5% CRM and 1.5% LC, the G*sin δ value is 4940 kPa, which is lower than the value obtained when LC is not present in the same formulation. In the same manner, the inclusion of LC in the mixture of PG64-22, 10% TLA, and 10% CRM results in a decrease in the G*sin δ value from 4000 kPa to 3580 kPa. Adding LC to PG64-22, 20% TLA, and 10% CRM results in a decrease in the G*sin δ value from 5950 kPa to 4430 kPa.
From a scientific standpoint, the decrease in G*sin δ values caused by LC signifies a reduction in the stiffness of the binder. This reduction is essential for minimizing the risk of fatigue cracking. This decrease in the value does not compromise the performance; instead, it harmonizes the requirement for exceptional performance with a diminished likelihood of cracking. Ultimately, the utilization of the warm mix additive LC has a beneficial impact on the creation of superior warm mix binders by decreasing the G*sin δ values, which in turn reduces the likelihood of fatigue cracking.

3.5. Thermal Cracking Property (Low Temperature)

The inclusion of LC significantly affects the stiffness. An example is the binder containing 10% TLA and 5% CRM, which exhibits a decrease in stiffness from 195.00 MPa to 177.00 MPa upon the inclusion of 1.5% LC. Similarly, the binder containing 20% TLA and 5% CRM experiences a decrease in value from 238.00 MPa to 185.00 MPa with LC. The observed pattern remains consistent in different binder formulations, including those containing 10% and 20% TLA combined with 10% CRM, where the addition of LC leads to a decrease in stiffness and is shown in Figure 6 and Figure 7 and Table 12. These observations suggest that the use of LC effectively reduces the hardness of the binder, making it less likely to develop cracks and enhancing its ability to withstand stress over time.
The m-value is a significant parameter that indicates the flexibility of a binder. Higher values indicate better performance, especially in terms of resistance to thermal cracking. The original/base binder, PG 64-22, possesses an m-value of 0.33. TLA incorporation results in a decrease in the m-value to 0.278 and 0.292 for TLA concentrations of 10% and 20% respectively, indicating a decrease in flexibility. Nevertheless, the addition of 5% CRM raises the m-value to 0.34, thereby improving the flexibility of the binder. The impact of LC is especially noticeable in its capacity to enhance the m-value in comparison to binders modified solely with PG 64-22 and TLA. However, LC does not exhibit significant influence when combined with CRM, as it demonstrates a decreasing trend. As an illustration, the binder containing 10% TLA and 5% CRM exhibits a reduction in m-value from 0.397 to 0.33 when 1.5% LC is added. In the binder containing 20% TLA and 5% CRM, a comparable pattern is seen where the m-value decreases from 0.322 to 0.25 with LC. The detrimental effect of LC on the m-value remains consistent across different formulations, demonstrating a decrease in flexibility and a reduction in resistance to thermal cracking when compared to a combination of CRM co-modified with TLA and petroleum binder (PG 64-22).
To summarize, the inclusion of LC as a warm mix additive has a beneficial impact on both stiffness and m-value in high-performance binders. The majority of the binder co-modified with LC exhibits a higher m-value exceeding 0.30, with the exception of the combination of 20% TLA and 5% CRM. LC decreases the rigidity of the binder, reducing its susceptibility to cracking and enhancing its resilience under stress, particularly in formulations containing higher levels of TLA and CRM. At the same time, LC improves the m-value, which shows increased flexibility and resistance to thermal cracking. This is important for achieving good performance in colder climates. The data substantiates the utilization of LC in warm mix asphalt compositions to attain high-performance binders with enhanced durability and elasticity, effectively harmonizing rigidity and pliability to fulfill diverse performance requirements in paving applications.

4. Conclusions

This study highlights the significant impact of the inclusion of Trinidad Lake asphalt (TLA), crumb rubber modifier (CRM), and warm mix additive l
Leadcap (LC) on the performance of PG 64-22 petroleum-based asphalt binders. The key findings are as follows:
  • Reduction in Viscosity: Addition of LC substantially decreases the viscosity of modified binders at temperatures of 135 °C and 180 °C, improving their ease of use and reducing the amount of energy needed for mixing and compacting. This decrease in viscosity is in line with the goals of warm mix asphalt technologies, which aim to reduce energy consumption and greenhouse gas emissions while still maintaining the necessary stiffness for optimal performance at high temperatures.
  • Enhanced Rutting Resistance: The inclusion of TLA, CRM, and LC significantly improves the ability of asphalt binders to resist rutting. The study found notable enhancements in both pre- and post-aging conditions, with LC demonstrating exceptional efficacy. The combination of PG64-22, 20% TLA, and 10% CRM demonstrated enhanced resistance to rutting and long-term durability, as verified by RTFO tests.
  • Improved Performance Metrics: The modifications resulted in significant enhancements in the percentage recovery (% rec) and non-recoverable creep compliance (Jnr). The combination of TLA, CRM, and LC led to improved flexibility and resistance to deformation, resulting in the development of high-performance warm mix asphalt binders.
  • Balanced Rigidity and Flexibility: The inclusion of LC consistently reduces the elevated rigidity and enhanced susceptibility to fatigue cracking that is commonly linked to higher levels of TLA and CRM. The equilibrium achieved guarantees a strong and reliable performance of the modified binders when exposed to elevated temperatures and demanding stress conditions.
  • Environmental Benefits: Enhanced formulations aid in environmental sustainability by decreasing energy usage and emissions throughout the production and paving of asphalt. Furthermore, these alterations improve the resilience and lifespan of the pavement.
In summary, this study demonstrates that LC is essential in developing strong, adaptable, and durable high-performance warm mix asphalt binders. The combined use of TLA, CRM, and LC not only improves ecological sustainability but also significantly enhances pavement performance, establishing a new benchmark for advanced asphalt technologies. With the proven high performance of the produced binder, future research will focus on developing a goose asphalt mixture for field application.

Author Contributions

Conceptualization, S.V.; Methodology, S.V.; Formal analysis, J.Y.; Resources, M.-S.L. and K.-D.J.; Data curation, S.V.; Writing—original draft, S.V.; Writing—review & editing, S.-J.L.; Supervision, J.Y. and S.-J.L.; Project administration, S.-J.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by a grant from a government funding project (2024 National Highway Pavement Management System).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data used to support the findings of this study are included within the article.

Conflicts of Interest

There are no conflicts of interest regarding the publication of this paper.

References

  1. Xu, S.; Huang, W.; Cai, F.; Huang, H.; Hu, C. Evaluation of properties of Trinidad Lake Asphalt and SBS-modified petroleum asphalt. Pet. Sci. Technol. 2019, 37, 234–241. [Google Scholar] [CrossRef]
  2. Brown, E.R.; Kandhal, P.S.; Roberts, F.L.; Kim, Y.R.; Lee, D.Y.; Kennedy, T.W. Hot Mix Asphalt Materials, Mixture Design, and Construction; NAPA Research and Education Foundation, 2009. [Google Scholar]
  3. Xiao, F.; Yao, S.; Wang, J.; Wei, J.; Amirkhanian, S. Physical and chemical properties of plasma treated crumb rubbers and high temperature characteristics of their rubberised asphalt binders. Road Mater. Pavement Des. 2020, 21, 587–606. [Google Scholar] [CrossRef]
  4. Wang, J.; Wang, T.; Hou, X.; Xiao, F. Modelling of rheological and chemical properties of asphalt binder considering SARA fraction. Fuel 2019, 238, 320–330. [Google Scholar] [CrossRef]
  5. Yan, K.; You, L. Investigation of Complex Modulus of Asphalt Mastic by Artificial Neural Networks; NISCAIR-CSIR: New Delhi, India, 2014. [Google Scholar]
  6. Maharaj, R. A comparison of the composition and rheology of Trinidad lake asphalt and Trinidad petroleum bitumen. Int. J. Appl. Chem. 2009, 5, 169–179. [Google Scholar]
  7. Fengler, R.Z.; Osmari, P.H.; Leite LF, M.; Nascimento LA, H.D.; Fritzen, M.A.; Aragão, F.T.S. Impact of the addition of Trinidad Lake Asphalt (TLA) on the rheological and mechanical behavior of two asphalt binders. Road Mater. Pavement Des. 2019, 20 (Suppl. S2), S827–S840. [Google Scholar] [CrossRef]
  8. Widyatmoko, I.; Elliott, R. Characteristics of elastomeric and plastomeric binders in contact with natural asphalts. Constr. Build. Mater. 2008, 22, 239–249. [Google Scholar] [CrossRef]
  9. Feng, X.; Zha, X.; Hao, P. Research on design technology of TLA modified asphalt mixture. Open Mater. Sci. J. 2011, 5. [Google Scholar] [CrossRef]
  10. Vigneswaran, S.; Yun, J.; Kim, H.; Lee, M.S.; Lee, S.J. Enhancing Asphalt Binder Performance and Storage Stability with Trinidad Lake Asphalt (TLA). Appl. Sci. 2024, 14, 6023. [Google Scholar] [CrossRef]
  11. Liu, J.; Yan, K.; Liu, J.; Guo, D. Evaluation of the characteristics of Trinidad Lake Asphalt and Styrene–Butadiene–Rubber compound modified binder. Constr. Build. Mater. 2019, 202, 614–621. [Google Scholar] [CrossRef]
  12. Xu, S.; Hu, C.; Yu, J.; Liu, R.; Zhou, X. Influence of Trinidad Lake Asphalt on the physical and anti-aging properties of petroleum asphalt. Pet. Sci. Technol. 2017, 35, 2194–2200. [Google Scholar] [CrossRef]
  13. Bressi, S.; Fiorentini, N.; Huang, J.; Losa, M. Crumb rubber modifier in road asphalt pavements: State of the art and statistics. Coatings 2019, 9, 384. [Google Scholar] [CrossRef]
  14. Presti, D.L. Recycled tyre rubber modified bitumens for road asphalt mixtures: A literature review. Constr. Build. Mater. 2013, 49, 863–881. [Google Scholar] [CrossRef]
  15. Wang, T.; Xiao, F.; Zhu, X.; Huang, B.; Wang, J.; Amirkhanian, S. Energy consumption and environmental impact of rubberized asphalt pavement. J. Clean. Prod. 2018, 180, 139–158. [Google Scholar] [CrossRef]
  16. Picado-Santos, L.G.; Capitão, S.D.; Neves, J.M. Crumb rubber asphalt mixtures: A literature review. Constr. Build. Mater. 2020, 247, 118577. [Google Scholar] [CrossRef]
  17. Kaloush, K.E.; Biligiri, K.P. Asphalt-Rubber Standard Practice Guide; Links: West Devon, UK, 2011. [Google Scholar]
  18. Vigneswaran, S.; Yun, J.; Jeong, K.D.; Lee, M.S.; Lee, S.J. Effect of Crumb Rubber Modifier Particle Size on Storage Stability of Rubberized Binders. Sustainability 2023, 15, 13568. [Google Scholar] [CrossRef]
  19. Yun, J.; Vigneswaran, S.; Lee, M.S.; Lee, S.J. A Laboratory Investigation Regarding Storage Stability of the CRM-Modified Bitumen—CRM Processing Method (Untreated vs. Treated). Sustainability 2023, 15, 10825. [Google Scholar] [CrossRef]
  20. Yun, J.; Vigneswaran, S.; Lee, M.S.; Choi, P.; Lee, S.J. Effect of Blending and Curing Conditions on the Storage Stability of Rubberized Asphalt Binders. Materials 2023, 16, 978. [Google Scholar] [CrossRef] [PubMed]
  21. Kim, H.; Jeong, K.D.; Lee, M.S.; Lee, S.J. Performance properties of CRM binders with wax warm additives. Constr. Build. Mater. 2014, 66, 356–360. [Google Scholar] [CrossRef]
  22. Mazumder, M.; Kim, H.; Lee, S.J. Performance properties of polymer modified asphalt binders containing wax additives. Int. J. Pavement Res. Technol. 2016, 9, 128–139. [Google Scholar] [CrossRef]
  23. Jamrah, A.A.; Kutay, M.E. A new rheological approach to evaluating the aged performance of Crumb Rubber Modified binders. Int. J. Pavement Eng. 2022, 23, 1897–1910. [Google Scholar] [CrossRef]
  24. ASTM D5-06e1; Standard Test Method for Penetration of Bituminous Materials. ASTM International: West Conshohocken, PA, USA, 2013.
  25. ASTM D70-18a; Standard Test Method for Density of Semi-Solid Asphalt Binder (Pycnometer Method). Annual Book of Standards. ASTM International: West Conshohocken, PA, USA, 2018.
  26. ASTM D36; Standard Test Method for Softening Point of Bitumen (Ring-and Ball Apparatus). American Association of State and Highway Transportation Officials: Washington, DC, USA, 2014.
  27. D92-18; Standard Test Method for Flash and Fire Points by Cleveland Open Cup Tester. ASTM International: West Conshohocken, PA, USA, 2018.
  28. ASTM D2872-19; Standard Test Method for Effect of Heat and Air on a Moving Film of Asphalt (Rolling Thin-Film Oven Test). ASTM International: West Conshohocken, PA, USA, 2019.
  29. ASTM D6521-19; Standard Practice for Accelerated Aging of Asphalt Binder Using a Pressurized Aging Vessel (PAV). ASTM International: West Conshohocken, PA, USA, 2019.
  30. AASHTO T 313-12; Standard Method of Test for Determining the Flexural Creep Stiffness of Asphalt Binder Using the Bending Beam Rheometer (BBR). American Association of State Highway and Transportation Officials: Washington, DC, USA, 2012.
  31. AASHTO T 316-13; Standard Method of Test for Viscosity Determination of Asphalt Binder Using Rotational Viscometer. American Association of State Highway and Transportation Officials: Washington, DC, USA, 2013.
  32. AASHTO T 315-12; Standard Method of Test for Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR). American Association of State Highway and Transportation Officials: Washington, DC, USA, 2012.
  33. AASHTO TP 70-10; Standard Method of Test for Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a Dynamic Shear Rheometer. American Association of State Highway and Transportation Officials: Washington, DC, USA, 2010.
  34. Ott, R.L.; Longnecker, M. An Introduction to Statistical Methods and Data Analysis; Cengage Learning: Boston, MA, USA, 2016. [Google Scholar]
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Figure 1. Experimental method.
Figure 1. Experimental method.
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Figure 2. Viscosity values at 135 °C and 180 °C of the modified binders.
Figure 2. Viscosity values at 135 °C and 180 °C of the modified binders.
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Figure 3. G*/sin δ at 64 °C of the modified binders at original and RTFO conditions.
Figure 3. G*/sin δ at 64 °C of the modified binders at original and RTFO conditions.
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Figure 4. % Recovery and Jnr at 64 °C of the modified asphalt binders at Original and RTFO condition.
Figure 4. % Recovery and Jnr at 64 °C of the modified asphalt binders at Original and RTFO condition.
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Figure 5. G*sin δ at 25 °C of the modified binders at RTFO + PAV aged conditions.
Figure 5. G*sin δ at 25 °C of the modified binders at RTFO + PAV aged conditions.
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Figure 6. Stiffness at −12 °C of the modified asphalt binders after RTFO + PAV aged condition.
Figure 6. Stiffness at −12 °C of the modified asphalt binders after RTFO + PAV aged condition.
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Figure 7. m-Value at −12 °C of the modified asphalt binders after RTFO + PAV aged condition.
Figure 7. m-Value at −12 °C of the modified asphalt binders after RTFO + PAV aged condition.
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Table 1. Properties of original asphalt binder (PG 64-22).
Table 1. Properties of original asphalt binder (PG 64-22).
States of AgingTest PropertiesTest Result
Unaged binderViscosity @ 135 °C (cP)755
Viscosity @ 180 °C (cP)285
G*/sin δ @ 64 °C (kPa)2.01
RTFO aged residualG*/sin δ @ 64 °C (kPa)5.25
RTFO + PAV
aged residual		G*sin δ @ 25 °C (kPa)3400
Stiffness @ −12 °C (MPa)185
m-value @ −12 °C0.33
Table 2. Properties of Trinidad Lake asphalt.
Table 2. Properties of Trinidad Lake asphalt.
PropertiesTest MethodTest Result
Penetration (25 °C)ASTM D5 [24]1–4
DensityASTM D70 [25]1.40–1.42 g/m3
Softening pointASTM D36 [26]199 °F–208 °F
Flash pointASTM D92 [27]255 °C–266 °C
Fire pointASTM D92 (Cleaveland open cup) [27]305 °C–310 °C
Table 3. Gradation of CRM used in this study.
Table 3. Gradation of CRM used in this study.
Sieve Number% Cumulative Passed Size ≤ 0.5 mm
#4100
#8100
#30100
#5058
#10017
#2002.3
Table 4. Chemical properties and physical properties of Leadcap-64.
Table 4. Chemical properties and physical properties of Leadcap-64.
PropertySynonym/Content (%)
Chemical Properties
PolyethylenePolyethylene
Content (%)43–54
Zinc distearateOctadecanoic acid, zinc salt
Content (%)18–25
Hydrogenated Palm OilPalmitic acid
Content (%)25–30
Physical Properties
Specific gravity0.91–0.95 g/cm3
Melting point100–120 °C
Table 5. Statistical analysis values of the viscosity at 135 °C of binders modified as a function of different combinations (α = 0.05).
Table 5. Statistical analysis values of the viscosity at 135 °C of binders modified as a function of different combinations (α = 0.05).
Viscosity at Original Condition at 135 °C
CombinationPG64-22PG
64-22 + 10%TLA		PG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%CRMPG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
135CPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SSSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----- - --SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 6. Statistical analysis values of the viscosity at 180 °C of binder modified as a function of different combinations (α = 0.05).
Table 6. Statistical analysis values of the viscosity at 180 °C of binder modified as a function of different combinations (α = 0.05).
Viscosity at Original Condition at 180 °C
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%
CRM		PG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
180CPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SNSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----------SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 7. Statistical analysis values of the G*/sin δ at 64 °C of asphalt binders modified as a function of different combinations (α = 0.05).
Table 7. Statistical analysis values of the G*/sin δ at 64 °C of asphalt binders modified as a function of different combinations (α = 0.05).
Viscoelasticity at Original Condition at 64 °C
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%
CRM		PG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
64CPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SSSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----------SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 8. Statistical analysis values of the G*/sin δ at 64 °C of asphalt binders modified as a function of different combinations at RTFO condition (α = 0.05).
Table 8. Statistical analysis values of the G*/sin δ at 64 °C of asphalt binders modified as a function of different combinations at RTFO condition (α = 0.05).
Viscoelasticity RTFO Condition at 64 °C
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%LCPG64-22 + 20%TLA + 5%CRMPG64-22 + 20%TLA + 5% CRM + 1.5%LCCRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%LCPG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%LC
64CPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SSSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----------SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 9. Statistical analysis values of the % recovery at 64 °C of asphalt binders modified as a function of different combination at original conditions (α = 0.05).
Table 9. Statistical analysis values of the % recovery at 64 °C of asphalt binders modified as a function of different combination at original conditions (α = 0.05).
% Recovery Original Condition at 64 °C
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%
CRM		PG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
64CPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SSSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----------SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 10. Statistical analysis values of the % recovery at 64 °C of asphalt binders modified as a function of different combination at RTFO conditions (α = 0.05).
Table 10. Statistical analysis values of the % recovery at 64 °C of asphalt binders modified as a function of different combination at RTFO conditions (α = 0.05).
% Recovery RTFO Condition at 64 °C
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%
CRM		PG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
64CPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SSSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----------SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 11. Statistical analysis results of the (RTFO + PAV) of modified asphalt binders at 25 °C as a function of different combinations (α = 0.05).
Table 11. Statistical analysis results of the (RTFO + PAV) of modified asphalt binders at 25 °C as a function of different combinations (α = 0.05).
PAV Condition at 25 °C
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%
CRM		PG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
RTFO + PAVPG64-22-SSSSSSSSSSSS
PG64-22 + 10%TLA--SSSSSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSS
PG64-22 + 10%TLA + 10%CRM----------SSS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
Table 12. Statistical analysis values of the stiffness (RTFO + PAV) of asphalt binders modified at −12 °C as a function of different combinations (α = 0.05).
Table 12. Statistical analysis values of the stiffness (RTFO + PAV) of asphalt binders modified at −12 °C as a function of different combinations (α = 0.05).
RTFO + PAV
CombinationPG64-22PG64-22 + 10%TLAPG64-22 + 20%TLACRM 5%PG64-22 + 10%TLA + 5% CRMPG64-22 + 10%TLA + 5% CRM + 1.5%
LC		PG64-22 + 20%TLA + 5%
CRM		PG64-22 + 20%TLA + 5% CRM + 1.5%
LC		CRM 10%PG64-22 + 10%TLA + 10%CRMPG64-22 + 10%TLA + 10% CRM + 1.5%
LC		PG64-22 + 20%TLA + 10%CRMPG64-22 + 20%TLA + 10% CRM + 1.5%
LC
RTFO + PAV PG64-22-SSSSSSNSSSSS
PG64-22 + 10%TLA--SSSNSSSSSSS
PG64-22 + 20%TLA---SSSSSSSSSS
CRM5%----SSSSSSSSS
PG64-22 + 10%TLA + 5% CRM-----SSSSSSSS
PG64-22 + 10%TLA + 5% CRM + 1.5%LC------SSSSSSS
PG64-22 + 20%TLA + 5%CRM-------SSSSSS
PG64-22 + 20%TLA + 5% CRM + 1.5%LC--------SSSSS
CRM10%---------SSSN
PG64-22 + 10%TLA + 10%CRM----------SNS
PG64-22 + 10%TLA + 10% CRM + 1.5%LC-----------SS
PG64-22 + 20%TLA + 10%CRM------------S
PG64-22 + 20%TLA + 10% CRM + 1.5%LC-------------
S—Significant, N—Non-significant.
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Vigneswaran, S.; Yun, J.; Lee, M.-S.; Jeong, K.-D.; Lee, S.-J. Revolutionizing Roadways: High-Performance Warm Mix Asphalt Binder with Trinidad Lake Asphalt and Recycled Tire Rubber. Appl. Sci. 2024, 14, 7211. https://doi.org/10.3390/app14167211

AMA Style

Vigneswaran S, Yun J, Lee M-S, Jeong K-D, Lee S-J. Revolutionizing Roadways: High-Performance Warm Mix Asphalt Binder with Trinidad Lake Asphalt and Recycled Tire Rubber. Applied Sciences. 2024; 14(16):7211. https://doi.org/10.3390/app14167211

Chicago/Turabian Style

Vigneswaran, Shyaamkrishnan, Jihyeon Yun, Moon-Sup Lee, Kyu-Dong Jeong, and Soon-Jae Lee. 2024. "Revolutionizing Roadways: High-Performance Warm Mix Asphalt Binder with Trinidad Lake Asphalt and Recycled Tire Rubber" Applied Sciences 14, no. 16: 7211. https://doi.org/10.3390/app14167211

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