Low-temperature Performance Of Asphalt Mixture Research Articles

Feasibility and performance of the Semi-circular Bending test in evaluating the low-temperature performance of asphalt mortar

Semi-circular Bending (SCB) test has been widely used to evaluate the fracture performance of asphalt mixtures, but its potential in evaluating the low-temperature performance of asphalt mixtures at mortar scale has been seldom investigated. This study aims to explore the feasibility and evaluate the performance of SCB tests in evaluating the low-temperature performance of asphalt mortar. To quantify the influence of the crushing and local creep at the top of the SCB test samples on testing results, the Digital Image Correlation (DIC) method was used to characterize the displacement field of mortar samples during the test under different loading rates at −10 °C. The effects of binder film thickness, filler content, and aging condition on low-temperature performance of asphalt mortar were investigated by SCB test. The experimental design set a fixed nominal maximum aggregate size of 4.75 mm. The test matrix considered three binder film thicknesses (9, 10 and 11 µm) and four filler contents (8.5%, 9.4%, 10.5% and 11%) at two aging conditions (short-term and long-term aging). Two cracking indexes including before-peak slope (Sbp) and fracture energy (Gf) were used to evaluate the low-temperature performance. According to the results of DIC analysis, the loading rate of 3 mm/min was proposed to be the optimum for the SCB mortar test at −10 °C. It was concluded that the SCB mortar test can effectively differentiate the low-temperature cracking performance of different asphalt mortars under different aging conditions. Thicker binder film thickness can significantly decrease the aging rate of asphalt mortar from short-term aging to long-term aging, whereas the effect of filler content on ageing rate is not statistically significant.

The Impact of Recycled Concrete Aggregate on the Stiffness, Fatigue, and Low-Temperature Performance of Asphalt Mixtures for Road Construction

The need for road (re)construction materials is constantly growing. At the same time, there is a limited quantity of new, high-quality materials available and a buildup of secondary/recycled construction materials. One possible solution may be the use of recycled concrete aggregate (RCA) in asphalt mixtures instead of natural aggregate (NA), which also promotes economic and environmental sustainability. The potential use of fine and coarse RCA in road asphalt mixtures is analyzed in this work. Nine asphalt mixtures were tested for base course layers, where RCA was used as a NA substitute. The impact of the quantity of RCA (up to 45% by mass) on the resulting physical and mechanical properties of asphalt mixtures was investigated, and consequently compared with the properties of a reference control mixture produced with NA only. Results reveal that the addition of RCA requires higher bitumen in comparison to the control mixture (up to 1%). Consequently, mixtures with RCA had 15−20% lower stiffness and up to 26% higher critical fatigue strain value (ε6). Although RCA mixtures contained more bitumen, their low-temperature resistance was slightly inferior compared with the control mixture (failure temperatures were up to 4.3 °C higher). In conclusion, asphalt mixtures with up to 45% RCA can be used without substantially reducing performance.

Effect of basalt fiber on the low-temperature performance of an asphalt mixture in a heavily frozen area

In the present study, basalt fiber was used to enhance the low-temperature performance of asphalt mixtures in heavily frozen areas. By conducting three-point bending tests at various temperatures (−10 °C, −20 °C and −30 °C) and basalt fiber contents (0.2–0.5%), the changing trends of the bending stress, bending strain, and strain energy density were investigated and discussed. The fracture type of each asphalt mixture was distinguished based on the bending coefficient, and the micromorphology and microstructures of each basalt fiber-reinforced asphalt mixture were observed via scanning electron microscopy. The results show that basalt fiber effectively improves the low-temperature performance of an asphalt mixture and enhances its adaptability to a lower-temperature environment. The optimum fiber content of an AC-13 asphalt mixture is 0.4% based on its low-temperature performance, whereas that of an AC-20 mixture is 0.3%. Under the optimum fiber content, the low-temperature failure type of an asphalt mixture changes from brittle failure to flexible failure at −20 °C. The basalt fiber network enhances the integrity of the asphalt mixture and delays the extension of microcracks.

Modern, Recycled SMA Mixtures on the Illinois Tollway and Preliminary Performance-Based Mix Design Approach

As more recycled materials are utilized in modern asphalt mixtures, the overall phenomenological behavior of this important infrastructure material becomes more complex than ever, accelerating the need to supplement volumetric-based mix testing procedures with mixture mechanical tests. This paper introduces a mixture performance test based design approach, as a supplement to the current Superpave volumetric mix design approach, which is being implemented by several agencies near Chicago, Illinois, USA. For research purposes, the practical design suite, which considers the high and low-temperature performance of asphalt mixtures through Hamburg wheel tracking and disk-shaped compact tension fracture testing, has been supplemented by additional testing and analysis including creep compliance, performance-space diagram construction, and thermal cracking modeling using the software program ILLI-TC. Field cores from seven Illinois Tollway sites in Chicagoland with welltracked pavement performance were tested and analyzed using the aforementioned methods. These modern, high-performance stone matrix asphalt (SMA) recycled mixtures contained recycled asphalt pavement (RAP), reclaimed asphalt shingles (RAS), and ground tire rubber (GTR), and used a 3.5% design void target to promote mix durability. Rutting and cracking test results, and thermal cracking modeling predictions, were found to be consistent with field observations indicating near-zero rutting and cracking levels after up to eight years of heavy tollway traffic and severe mid-continental environmental conditions. In addition, the Hamburg-DC(T) performance space diagram was used to further analyze the results, demonstrating how this plotting tool can be used to adjust future mix designs to yield even longer life on the Tollway system at little-to-no extra cost.

Investigation of the Performance of Basalt Fiber Reinforced Asphalt Mixture

This study is focused on the effect of basalt fiber on the road performance of the asphalt mixture. The road performance of asphalt mixture with different dosages of basalt fiber was comprehensively evaluated using Marshall Stability test, the wheel tracking test, the three-point bending beam test and the freezing-thaw splitting test. The road performance of lignin fiber reinforced asphalt mixture and polyester fiber reinforced asphalt mixture also were tested to compare with the road performance of basalt fiber reinforced asphalt mixture. The results showed that basalt fiber can enhance mechanical properties, the low-and high-temperature performance and water sensitivity of the asphalt mixture significantly. Considering the road performance and economic benefits, the appropriate dosage of basalt fiber is about 0.3%. Marshall Stability (MS), dynamic stability (DS), the maximum bending strain and the tensile strength ratio (TSR) of asphalt mixture with 0.3% basalt fiber were increased by 19.6%, 25.5%, 22.2% and 6.0%, respectively. Basalt fiber has certain advantages in improving the low-temperature performance of asphalt mixture by comparison with lignin fiber and polyester fiber.

Low-temperature performance of asphalt mixture based on statistical analysis of winter temperature extremes: A case study of Harbin China

Abstract Winter temperature extremes are of major interest due to their potential damaging impacts related to pavement temperature and thermal cracking. In the present paper, three climate indices are adopted to describe the feature of winter temperature extremes. Statistical models for indices are analyzed based on the observed data in Harbin. The threshold values with their 99.9% cumulative frequency are proposed. Experiments were carried out in order to investigate the impacts of winter temperature extremes on pavement temperature and low-temperature performance of asphalt mixture. The results show that Weibull distribution is an appropriate model in the discussion of air temperature and its duration, and Frechet is the best-fitted model for the rate of air temperature change. Comparisons of experimental results indicate the importance of winter temperature extremes to asphalt pavement temperature. The influence of low-temperature properties by different temperature conditions is also analyzed. The low-temperature performance in Harbin can be accurately quantified by linear interpolation.

Low-temperature performance of SBS modified asphalt mixture in high altitude and cold regions

Due to the severe natural environment found in high-altitude and cold regions, where the altitude is around 4000 m, and the average annual temperature is below 0°C, the design method and quality indicators of asphalt mixture performance is different in comparison to inland cities. To optimize design parameters and low-temperature performance of SBS modified asphalt mixture in high-altitude and cold regions, the beam bending, splitting, aging, and freez-thaw cycle tests were conducted based on the test protocol, field experience and quantitative analysis. Standard mixing procedures and evaluation indexes for low temperature anti-cracking performance were used to reveal the low temperature decaying characteristics of SBS modified asphalt mixtures. The results show that the optimum binder-aggregate ratio of 5.3% and the optimum SBS modifier dosage of 4%∼5% are recommended for SBS modified asphalt mixture in the high altitude and cold regions of the Tibetan Plateau. The splitting test is suitable for assessing low-temperature performance of asphalt mixtures in high altitude and cold regions with a loading rate adjusted to 2 mm/min. When the loading rate is adjusted to 10 mm/min, the beam bending test is suitable for studying the low-temperature performance of asphalt mixtures after long-term aging in high altitude and cold regions. The freezing and thawing split test is suitable for assessing low-temperature performance of asphalt mixtures after freezing and thawing in high altitude and cold regions when the loading rate is adjusted to 2 mm/min. Under long-term aging conditions, as temperature increases (−15°C∼0°C), the decay rate of maximum flexural-tensile strain of traditional asphalt mixture is bigger than that of SBS modified asphalt mixture. Having endured freezing and thawing cycles, the splitting strength and the maximum flexural-tensile strain of asphalt mixtures decreases. After 40 cycles of freezing and thawing, the maximum flexural-tensile strain decreases by 15.2% in comparison to state.

Effect of Double Recycled Reclaimed Asphalt Pavement (DRRAP) on Low-temperature Performance of Asphalt Mixture

Effect of Double Recycled Reclaimed Asphalt Pavement (DRRAP) on Low-temperature Performance of Asphalt Mixture

Evaluation of Asphalt Mixture Low-Temperature Performance in Bending Beam Creep Test.

Low-temperature cracking is one of the most common road pavement distress types in Poland. While bitumen performance can be evaluated in detail using bending beam rheometer (BBR) or dynamic shear rheometer (DSR) tests, none of the normalized test methods gives a comprehensive representation of low-temperature performance of the asphalt mixtures. This article presents the Bending Beam Creep test performed at temperatures from −20 °C to +10 °C in order to evaluate the low-temperature performance of asphalt mixtures. Both validation of the method and its utilization for the assessment of eight types of wearing courses commonly used in Poland were described. The performed test indicated that the source of bitumen and its production process (and not necessarily only bitumen penetration) had a significant impact on the low-temperature performance of the asphalt mixtures, comparable to the impact of binder modification (neat, polymer-modified, highly modified) and the aggregate skeleton used in the mixture (Stone Mastic Asphalt (SMA) vs. Asphalt Concrete (AC)). Obtained Bending Beam Creep test results were compared with the BBR bitumen test. Regression analysis confirmed that performing solely bitumen tests is insufficient for comprehensive low-temperature performance analysis.

Functionalization of reclaimed polyethylene with maleic anhydride and its application in improving the high temperature stability of asphalt mixtures

A process to improve the properties of reclaimed polyethylene (RPE) polymer modified asphalt mixture by grafting of maleic anhydride (MAH) onto RPE (RPE-g-MAH) in the presence of dicumyl peroxide (DCP) as initiator was proposed. Fourier transform infrared spectra (FTIR) was employed to verify the grafting of MAH onto RPE. Modified asphalt mixture under different conditions were investigated on the RPE-g-MAH samples. To assess the effects of the RPE-g-MAH on the high-temperature stability of modified asphalt mixture, we discussed dynamic stability (DS) and rutting depth (RD) of modified asphalt mixture by studying the influences of various experimental parameters such as MAH content, DCP content, mixing temperature, wet mixing times and gradation type of mixture. Experimental results indicated that the RPE-g-MAH is feasible to improve high-temperature stability performance and low-temperature performance of asphalt mixture, and it could dramatically improve resistance to rutting of the asphalt mixture. Possible mechanism was proposed for RPE-g-MAH modification of asphalt mixture.

Low-Temperature Performance of Asphalt Mixtures Under Static and Oscillatory Loading

Nominal Maximum Aggregate Size (NMAS) significantly affects several mechanical properties of asphalt pavement both at low and high temperatures. Currently, aggregates with two NMAS, 9.5 and 12.5 mm, are widely used for surface layer in asphalt pavement. During the past decades, many agencies in the US have investigated the effect of NMAS aggregates on the field performance of asphalt mixtures. However, little research was performed to simultaneously evaluate the material behavior under static and oscillatory loading. This paper presents an experimental, laboratory-based, investigation to address the effect of two different NMAS aggregates, 9.5 and 12.5 mm, on the low-temperature properties of Hot Mix Asphalt (HMA). Two test types were selected for this purpose: Bending Beam Rheometer (BBR) mixture creep test, which is based on static loading, and Dynamic Shear Rheometer (DSR) mixture Complex Modulus test, which uses oscillatory loading. Based on the experimental data, Creep Stiffness, m-value (slope of logarithmic Creep Stiffness vs. time curve), Thermal Stress, Critical Cracking Temperature and Complex Modulus are calculated and, then, statistically and graphically compared. Significant differences in mechanical performance were observed between NMAS 9.5 and 12.5 mm HMA mixtures under static loading conditions. However, in case of oscillatory loading, mixtures prepared with softer binder showed smaller differences in Shear Complex Modulus, |G*|, between mixtures having NMAS 9.5 and 12.5 mm compared to mixtures with a stiffer binder. Air voids content (4 and 7 %) did not affect the measurement obtained with BBR and DSR except when aggregates with NMAS 9.5 mm and stiffer binders were used.

The Effect of Asphalt and Aggregate Gradation on the Low-Temperature Performance of Asphalt Mixtures for Intermediate and Underlying Course

Aiming at the asphalt mixture type used in intermediate and underlying course of high-grade highways in Northeast region of China, the research of effect of asphalt and gradation on the low-temperature performance of asphalt mixture was carried out to recommend asphalt grade and grading type which is suitable for intermediate and underlying course of high-grade highway in Northeast region of China. The results show that the asphalt and gradation of aggregate has important impact on the low-temperature performance of asphalt mixture. The low-temperature bending creep rate of Grade A No.90 asphalt mixture specimen prepared is faster than that of Grade A No.70 asphalt mixture. To further illustrate the low-temperature deformation resistance performance of Grade A No.90 asphalt is better than that of Grade A No.70.asphalt.The low-temperature bending creep rate of modified asphalt mixture of gradation GLAC-20 is greatly improved. Grade A No.90 asphalt modified is suggested to use in intermediate course, and the gradation type which is suitable for intermediate and underlying course is recommended for reference.

Study on Low-Temperature Performance of Asphalt Mixture Impacted by Modified Asphalt and Polyester Fibers

Low temperature crack plays an important role on the road safety and comfort. Indoor experiments were carried out to study the crack resistance of asphalt mixture. The results show that: fiber and SBS modified asphalt can increase the failure strain energy, the failure stress and the failure strain and reduce stiffness, thus can significantly improve the anti-cracking ability at low temperature; at a critical temperature of about -10°C, the splitting strength achieve a peak value correspondingly, and the asphalt mixture transforms from the viscoelastic status to the brittle status; the failure load and the failure strain of the three kinds of mixtures are in the sequence of modified asphalt mixture> fiber mixture> common asphalt mixture; the results of the J-integral strain energy test show that fiber asphalt mixture has the maximum resistance curve slope, which means it may have better anti-cracking ability than the SBS modified asphalt mixture; the fracture stiffness can be introduced to effectively evaluate the crack resistance of asphalt mixture.

Analysis of the Evaluation Indices from TSRST

AbstractBecause the thermal stress restrained specimen test (TSRST) is recommended by the Strategic Highway Research Program (SHRP) as a test method to evaluate low-temperature cracking resistance of asphalt mixtures, many studies have been carried out to investigate the performance of asphalt mixture with this test using fracture temperature as the indicator. However, few of them focus on discussing its reliability. In this paper, six kinds of asphalts mixtures are evaluated by TSRST, and it is found that the evaluation results obtained by the four indices are contradictory. It is also inferred from the results of each index coefficient of variation that fracture temperature and transition temperature are more stable when they are used to evaluate low-temperature performance of asphalt mixtures. Through the application of principal-component analysis (PCA) and the Boston Consulting Group’s matrix on the TSRST results, it is demonstrated that fracture temperature used as the indicator of low-temperature p...

Research on Relationship between Aging State and Low-Temperature Performance of Asphalt Mixture

Abstract Aging phenomenon of asphalt material exists in the course of mixing, spreading, and rolling of asphalt mixture, as well as the use in the asphalt pavement. The indirect tensile strength test was used to evaluate the performance of asphalt mixtures at low-temperature under different aging conditions. As compared with the results from the original short-term aging and the long-term aging asphalt mixtures, the results show that the original asphalt mixture cannot reflect the real performance of the asphalt mixture in the field. The short-term aging specimens are more sensitive than long-term aging specimens in evaluating the performance of the asphalt mixture at low temperature. Tests results also indicate that the consideration of aging during the evaluation of asphalt pavement performance is necessary.