Anti-rutting Agent Research Articles

Determining the Compaction Temperature of Warm-Mix Anti-Rutting Asphalt Mixture

In order to study the effect of a warm-mix agent on the compaction characteristics of an anti-rutting asphalt mixture, this study compared the compaction temperature of an anti-rutting asphalt mixture with different warm-mix-agent contents from two aspects: asphalt viscosity and asphalt mixture voids. Based on the rheological properties of asphalt, the optimal content of the anti-rutting agent was first determined as 6% by the weight of asphalt. Four warm-mix-agent contents of 0% (control group), 1%, 2%, and 3% were designed. The viscosity–temperature curve of the warm-mix anti-rutting modified asphalt was obtained by the Brookfield viscosity tests. After that, AC-20 standard Marshall specimens were prepared to conduct a series of consecutive temperature compaction tests. The voids were calculated based on the bulk density of the specimen measured by the saturated surface-dry method. Industrial Computerized Tomography (CT) was employed to further quantify the internal voids. Two voids–compaction temperature curves were constructed based on the saturated surface-dry and CT results, respectively. The comparative results show that significant differences exist between the compaction temperatures obtained from the three curves. The viscosity–temperature curve shows that when the warm-mix agent is increased from 0% to 3%, the compaction temperature only declines about 7.9%. However, the voids–compaction temperature curves from saturated surface-dry and CT, respectively, indicate a temperature decrease of 22.7% and 19.2%. This is because a warm-mix agent will interact with asphalt, resulting in a decrease in asphalt intermolecular adsorption, whereas an anti-rutting agent mixed with asphalt will increase the degree of cross-linking and aggregation between asphalt molecules. Both additions have a certain impact on the viscosity of the asphalt binder; thus the traditional method of using the asphalt viscosity–temperature curve to determine the compaction temperature of warm-mix anti-rutting asphalt mixture has become ineffective. It is suggested to use the equal voids method to determine the compaction temperature of warm-mix anti-rutting asphalt mixtures.

Development and characterization of permeative anti-rutting agent for asphalt mixture enhancement

Rutting distress has adverse effects on driving safety and comfort. However, how to enhance the rutting resistance of specific pavement sections contrapuntally and flexibly still requires further study. A permeative anti-rutting agent (PARA) based on epoxy resin and Buton rock asphalt was developed in this study to enhance the rutting resistance of asphalt pavement. It can improve the rutting resistance by permeating and curing in the asphalt pavement. Its optimum composition was characterized and determined at first. PARA’s effect on pavement performance of asphalt mixture was then tested and analyzed. Results suggested that the optimum mass proportion of epoxy resin, curing agent, curing accelerator and Buton rock asphalt was determined as 1.6:1:0.02:0.32. The lowest exudative percentage of PARA was found when its content was 0.9%. Higher PARA content will result in lower void volume and void in mineral aggregate of asphalt mixture. The mixture’s Marshall stability, moisture resistance, and dynamic stability were positively correlated to PARA’s content. The lowest flexural tensile strain and flexural tensile strength in low temperature occurred when PARA content was 0.9%. Asphalt mixture with 0.90% PARA showed optimum fatigue performance and aging resistance. Therefore, PARA can be used to enhance the asphalt pavement at low cost. Its advantage in flexibility and convenience results in its excellent application prospect.

Performance evaluation of lignin-fibre reinforced asphalt mixture modified by anti-rutting agent

• The ARA could enhance the road performance of the LFSMA-13 for different ages and decrease the performance sensitivity to age. • The lignin fibers physically interact with the asphalt, while the ARA could chemically interact with the asphalt mixture. • The peak area of the imino and methyl in the asphalt decreases, and the peak area of the carbonyl and sulfoxide increases with age. • The correlation between the peak areas of imino, methyl, carbonyl, and sulfoxide, and the physical property indices of the LFSMA-13 and ALSMA-13 is good. This paper aims to analyze the long-term road performance of anti-rutting agent (ARA) reinforced asphalt mixture, and reveal its road performance from the micro morphology and chemical perspective. ARA was used to modify the lignin fiber-reinforced SMA-13 asphalt mixture (LFSMA-13). The unaged, and the short and long-term aged specimens were used to test the road performance (high and low-temperature properties, water stability, and anti-cracking) of the LFSMA-13 and ARA modified LFSMA-13 (ALSMA-13). In addition, the micromorphology of the additives and asphalt mixture and the chemical property of asphalt in the mixture were analyzed using the scanning electron microscope (SEM) test and Fourier transform infrared (FTIR) test. The relationship between road performance and chemical property was also analyzed. The results showed that the performance of the ALSMA-13 was better with age than the LFSMA-13. The SEM images showed that the lignin fiber and the ARA could form a network structure in the SMA-13 mixtures. The FTIR test indicated that the ARA's amino group (–NH–) could chemically interact with the asphalt in SMA-13. The peak area of the carbonyl and sulfoxide chemical group increased, and the imino and methyl decreased with age. The results showed a good correlation between the FTIR parameters and road performance.

Evaluation of the Aging of Styrene-Butadiene-Styrene Modified Asphalt Binder with Different Polymer Additives.

A wide variety of polymer additives have been widely used in recent years. However, the effect of different polymer additives on the durability of asphalt binders has not been investigated thoroughly. To evaluate the aging property of styrene-butadiene-styrene (SBS) asphalt binder with different polymer additives, three polymer modifiers, namely high modulus modifier (HMM), anti-rutting agent (ARA), and high viscosity modifier (HVM), were added to it. First, the Thin Film Over Test (TFOT) and Pressure Aging Vessel (PAV) was performed on the asphalt binders. The rheological properties of the four asphalt binders before and after aging were then checked by the Dynamic Shear Rheometer Test (DSR). The chemical compositions of the asphalt binders were determined by the Fourier Transform Infrared Spectrometer (FTIR) test. Several aging indicators were adopted to reflect the aging degree of the asphalt binders. The results show that when polymer additives are added to the SBS asphalt binder, the complex modulus, storage modulus, loss modulus, and rutting factor substantially increase and the phase angle decreases. All the test parameters become higher after aging. The phase angle of the SBS asphalt binder is the highest at both unaged and aged states, while its other parameters values are the smallest. Moreover, the Carbonyl Aging Indicator (CAI) of SBS with polymer additives becomes lower under both TFOT and PAV conditions, indicating that polymer additives can improve the aging resistance of SBS asphalt, of which HVM modifies the aging resistance best. Complex Modulus Aging Indicator (CMAI) and Storage Modulus Aging Indicator (SMAI) have the best correlation coefficients with CAI, and the two aging indicators can be used to predict the aging degree of polymer modified asphalt binders.

Effect of Different Polymer Modifiers on the Long-Term Rutting and Cracking Resistance of Asphalt Mixtures.

To evaluate the long-term performances of different polymer-modified asphalt mixtures, three modifiers were chosen to modify AC-13 (defined as the asphalt concrete with the aggregate nominal maximum particle size of 13.2 mm); namely, high viscosity modifier (HVM), high modulus modifier (HMM), and anti-rutting agent (ARA). The deformation and cracking resistance of different polymer-modified mixtures were checked at different aging conditions (unaged, short-term aged, and long-term aged for 5, 10, and 15 days respectively). The results of the Hamburg wheel-track test and uniaxial penetration test (UPT) showed that the rutting resistance of all asphalt mixtures changed in a V-shape as the aging progressed. From the unaged stage to the long-term aging stage (5 days), the rutting resistance decreases gradually. While after the long-term aging stage (5 days), the rutting resistance increases gradually. Results from the semicircular bending test (SCB) and the indirect tensile asphalt cracking test (IDEAL-CT) indicated that the cracking resistance of all the mixtures gradually decline with the deepening of the aging degree, indicating that aging weakens the crack resistance of asphalt mixtures. Additionally, test results showed that the rutting resistance of ARA AC-13 (defined as AC-13 containing ARA) is the best, the cracking resistances of ARA AC-13, HMM AC-13 (defined as AC-13 containing HMM) and HVM AC-13 (defined as AC-13 containing HVM) have no significant difference, and different polymer modifiers had different sensitivities to aging due to the polymer content and the type of modifier. The conclusions of this study help to further understand the long-term performance of polymer-modified asphalt mixtures during service life and to help guide the selection of modifiers for mixtures.

Permanent deformation characteristic of asphalt mixture under coupling effect of moisture, overload and loading frequency

To evaluate the influence of vehicle load and driving speed on permanent deformation characteristic of asphalt mixture in high temperature and rainy areas, the Hamburg wheel tracking test was conducted under different test conditions by changing the wheel load, loading frequency and test environment. The permanent deformation characteristic of asphalt mixture under coupling effect of moisture, overload and loading frequency was discussed. Meanwhile, three kinds of anti-rutting agents commonly used in engineering were selected, and the influence of various anti-rutting agents on permanent deformation characteristic of asphalt mixture was also studied by rutting test and Hamburg wheel tracking test. The results show that the moisture, load and loading frequency are important factors affecting the permanent deformation characteristic of asphalt mixture. Under coupling effect of moisture, overload and low loading frequency, the ability of asphalt mixture to resist the generation and development of permanent deformation is poor. The influence of coupling effect of moisture, overload and low loading frequency needs to be considered when evaluating the anti-rutting performance of asphalt mixture. After the addition of anti-rutting agent, the dynamic stability of asphalt mixture increases significantly first, and then tends to be gentle when the dosage of anti-rutting agent exceeds 0.45%. The difference of improvement effect of various anti-rutting agents on rutting resistance of asphalt mixture is obvious, and the improvement effect is in order of PR. PLASTS (PR) > RESIN ALLOY (RA) > Duroflex (Df). The anti-rutting agent PR with dosage of 0.45% is recommended to improve the resistance of asphalt mixture to permanent deformation. The research results can provide some references for improving the rutting resistance of asphalt pavement in high temperature and rainy areas.

Research on Applicability of Anti-rutting Agent LY to Different Asphalt Mixtures

In order to study the applicability of anti-rutting agent LY to different asphalt mixtures, six asphalt mixtures, including AC-16, AC-16+0.4% anti-rutting agent, SBS modified asphalt AC-16, SBS modified asphalt AC-16+0.4% anti-rutting agent, SMA-16, SMA-16+0.4% anti-rutting agen, were tested for high temperature performance, low temperature performance and water stability performance. The test results show that the anti-rutting agent LY can improve the high temperature performance, low temperature performance and water stability of AC-16 and SMA-16 asphalt mixtures, and the effect is best when used with AC-16 asphalt mixtures. Compared with SBS modified asphalt mixture, although anti-rutting agent LY can improve its high-temperature performance, it has a negative impact on its low-temperature performance and water stability, so it is not recommended to use anti-rutting agent LY together with SBS modified asphalt mixture.

Evaluation of High-Temperature Performance of Asphalt Mixtures Based on Climatic Conditions

The dynamic stability of a rutting test does not optimally reflect the high-temperature stability of asphalt mixtures. In this study, a rutting test was performed over a long duration (4 h) at different temperatures (40, 50, 60, 70 °C) for three asphalt mixtures, namely, matrix AC-16, SMA-16, and modified AC-16 asphalt mixtures. Subsequently, the temperature rutting rate was obtained after considering the annual temperature conditions of Guangdong and Beijing in China. Because the conditions of the rutting test were different from that of the actual pavement, the rut depth was calculated using a modified temperature rutting rate. This modification considered four factors: wheel trace distribution, temperature, pavement thickness, and loading rate. The calculation of the temperature rutting rate considered the climatic conditions and utilized the rutting deformation data from hour 1–4 of the rutting tests, during which the asphalt mixture was in a stable creep period. Thus, the high-temperature stability of the asphalt mixture was reflected more scientifically by the temperature rutting rate than the dynamic stability. The high-temperature rut-resistance of the asphalt mixture was found to improve significantly after the introduction of two additives (anti-rutting agent and lignin fiber). The modified formula for rut depth can realistically predict the annual rutting depth for three asphalt mixtures in a one-way driving pavement.

Experimental investigation of the road performance of terminal blend rubber asphalt mixture with different dry-way additives

Using wet-way composite modification method may result in the amount of ground tire rubber (GTR) in terminal blend rubber asphalt (TB) undetectable. So, it is of great interest to find out if dry-way modification method can substitute for wet-way composite modified asphalt to address the shortcomings of TB mixture. A laboratory experiment was developed for performance evaluation of TB asphalt mixtures with dry –way use polymer additives. The results showed that: (1) 5 hours was recommended as optimum processing time, since no obvious difference existed after TB asphalt modifying for 5 h and 7 h. (2) The incorporation of anti-rutting agent PLAST.S, GTR, polyester fiber (PF) and styrene-butadiene-styrene block copolymer (SBS) improved the rutting stability, resistance against low-temperature cracking, moisture stability and fatigue life of TB asphalt mixture, especially when PLAST.S and PF were used. (3) The use of GTR and PF brought obvious increase of mixing torques, resulting in more challenges to the workability of TB asphalt mixtures, whereas mixture with PLAST.S did not have a statistically significant difference with TB asphalt mixture. Therefore, according to the results obtained, PF can be used to replace TB/SBS composited modified asphalt since the two shared the most similar improvement of the properties of TB asphalt mixtures, while PLAST.S and GTR were also considered as good choices for modifying the TB asphalt mixture in dry-way.

Impacts of high modulus agent and anti-rutting agent on performances of airfield asphalt pavement

Polymer modifiers have been widely used in asphalt binders to improve the high temperature performances and rutting resistances in airfield pavement. The objective of this study was to investigate the high and low temperature performances of three polymers and styrene–butadienestyrene (SBS) modified binders before and after a short-term aging procedure, and the performances of their corresponding mixtures. A series of tests were performed to determine the effects of polymers on the binders and mixtures, such as rheological properties of the modified binders and engineering performances of mixtures at high and low temperatures. The test results show that, compared with the SBS modified binders, the polymer modifiers remarkably influenced on the virgin binders, and the high temperature performance of virgin binders with a high polymer modifiers content is similar to that of the SBS modified binders, but both SBS and polymers have negative impacts on low temperature performance. In terms of asphalt mixture, the polymer can enhance the adhesion of asphalt to improve the rutting resistance, and has appreciable effect on dynamic stability and moisture stability, but only the SBS modified asphalt mixtures with polymers have better pavement performance, the polymer modified virgin asphalt mixtures are still not applicable to the airfield pavement.

Laboratory and Field Investigation of the Feasibility of Crumb Rubber Waste Application to Improve the Flexibility of Anti-Rutting Performance of Asphalt Pavement.

Resistance of asphalt mix to low-temperature cracking and rutting at high temperature is very important to ensure the service performance of asphalt pavement under seasonal changes in temperature and loading. However, it is challenging to balance the improvement of such resistance by using additives, e.g., anti-rutting agent (ARA). This study focuses on improving the flexibility of anti-rutting asphalt mix by incorporating crumb rubber (CR) and ARA. The properties of the prepared modified asphalt mix were evaluated in the laboratory by performing wheel tracking, three-point bending, indirect tensile, and uniaxial compression tests. The experimental results showed that the dynamic stability of modified asphalt mix was significantly increased due to the addition of ARA and further improved by incorporating CR. The maximum bending strain at −10 °C was increased due to the contribution of CR. The results of indirect tensile strength and resilient modulus further indicated that the CR-modified anti-rutting mixture was more flexible. Moreover, the field observation and evaluation indicated that the CR-modified anti-rutting asphalt pavement met the standard requirements, better than normal asphalt mixture in many parameters. A conclusion can be made that incorporating CR in asphalt mixture prepared with ARA can improve pavement performance at both high and low in-service temperatures.

Chemical, thermal and rheological characteristics of composite polymerized asphalts

Thermal oxidation has a significant effect on rheological and chemical properties of composite polymerized asphalt. In this study, polyethylenes (PE) and a multi-polymer (a type of anti-rutting agent) were incorporated into asphalt binders at four contents and the properties of polymer-asphalt composite systems were investigated through chemical functional group, molecular size, thermal behavior and rheological characteristics. Due to the formation of large conjugate structure by thermal oxidation, the carbonyl peak shifted to a lower wavenumber after a long-term aging procedure and the aging procedure increased the values of large molecular sizes. However, the degradation of PE played a dominant role during oxidation progress, which significantly decreased the LMS value of composite binders. Therefore the aging process changed the chemical compositions and element component distribution of binders and these changes were influenced by both binder source and polymer contents. In addition, with the increase of polymer modification, the penetration value and phase angle value at low frequency decreased; the endothermic peak area, softening point as well as complex shear modulus at low frequency increased. Therefore, the polymer degradation and polycyclic aromatic hydrocarbon formation should be considered during the aging process, which influenced the rheological performance of composite polymerized asphalts together. Furthermore, the correlation analysis showed that the carbonyl structure index ICdbndO has significant correlations with the difference between glassy modulus and equilibrium modulus, and phase angle master curve plateau δP, the LMS value has significant relationships with phase angle master curve factors δL and δP + δL at a low frequency.

Performance investigation and sustainability evaluation of multiple-polymer asphalt mixtures in airfield pavement

Abstract Increasing aircraft loads and landing frequency are becoming challenges to airfield pavement material design. The objective of this study was to give overall performances of multiple-polymer asphalt mixtures containing anti-rutting agent (ARA), polyethylene (PE) and styrene-butadiene-styrene (SBS). A series of binder and mixture tests were conducted to investigate mechanical performances, the life-cycle assessment (LCA) was used to evaluate environmental impacts. It was found that the addition of multiple-polymer resulted in excellent high temperature performance with high rutting factor and softening point, but it led to large energy consumption and GHG emission. Also, SMA-13 mixture had larger environmental impacts than AC-20 due to higher binder content. The radar chart and rheology-environment performance ratio (REPR) were proposed to compare rheological performances and environmental impacts with respect to polymer content and test temperatures. The field practice of HMA overlay selected 0.2% of ARA and 0.5% of PE by weight of asphalt mixture as the optimal polymer content. It was found that the multiple-polymer mixture had a great resistance to permanent deformation and enough resistances to moisture damage and low temperature cracking. However, the quality control of pavement construction was not effective because air voids of cored specimens exceeded the requirement even though other properties were satisfied with the requirements. In addition, compared with HMA, the WMA compacted at 155 °C had lower air void and maximum bending strain. Therefore, the application of WMA additives in multiple-polymer modified asphalt mixture should be further studied.

Design of SMA - 13 asphalt mixture ratio on Z3and Z18 of the capital airport

According to the demand of T2 terminal airlines to operate A380 models, to meet the smooth running of the A380 airliner at the west end of the Capital Airport, So Z3 and Z18 taxiway area of the transformation is imperative. According to the design, the upper layer of this project adopts SMA - 13 modified asphalt mastic macadam mixture. We design the SMA-13 modified asphalt mixture on Z3 and Z18 of the capital airport from any respects, including coarse and fine aggregate, filler, asphalt, fiber and anti-rutting agent, and we hope we can find the best SMA-13 modified asphalt mixture.

Impacts of multiple-polymer components on high temperature performance characteristics of airfield modified binders

Polymer modified asphalt binders have been commonly used to improve the resistance of the airfield pavements to distresses, especially wheel rutting. The objective of this study was to investigate the rheological and chemical properties of the modified binders containing anti-rutting agent (ARA), polyethylene (PE) and styrene-butadiene-styrene copolymer (SBS) before and after a short-term aging procedure. Rotational viscosity, penetration degree, softening point as well as performance grade, multi-stress creep recovery (MSCR), frequency and amplitude sweep were performed to determine the effects of ARA and PE on rut depths at high temperatures. In addition, Fourier Transform Infrared Spectroscopy (FTIR) was conducted to determine the chemical properties of various polymerized binders. The test results showed that, as expected, the addition of PE and ARA polymer increased the rotational viscosity, softening point and rutting factor values and reduced the penetration degree. However, ARA could only increase complex modulus while PE had the influences on both the complex modulus and phase angle of the modified binders. In addition, the rising tendency of phase angle during frequency sweep test was totally different in terms of the binders with or without PE. Furthermore, the FTIR test results showed that the ARA has no significant effects on aging resistance, while the modified binders with PE have better resistance to aging.

Laboratory investigation on the properties of asphalt mixtures modified with double-adding admixtures and sensitivity analysis

In order to improve the high temperature stability and low temperature cracking resistance of asphalt mixtures, two varieties of admixtures (anti-rutting agent and lignin fiber) were selected and then combined. This is called double-mixture technology. A series of tests about pavement performance of base asphalt mixtures and asphalt mixtures with admixture of anti-rutting agent or lignin fiber were conducted. Meanwhile sensitivity analyses were used to study the influence of three factors (i.e., asphalt grade, aggregate type and gradation) on the high and low temperature performance and water stability of said asphalt mixtures. Test results indicated that the dynamic stability, residual stability, TSR and low temperature failure strain of asphalt mixtures have increased significantly with the additions of 0.40% anti-rutting agent and 0.36% lignin fiber. These results show that the high and low temperature and water stabilities of asphalt mixtures improve obviously. This supports the beneficial comprehensive effect of the double admixture. The problem of improving the asphalt mixtures performance with a single admixture is solved, in addition to also improving other pavement performance. Based on the sensitivity analysis, the most influential factors of dynamic stability, low temperature failure strain and TSR are the gradation, followed by asphalt grade and aggregate type.

High-temperature performance of multilayer pavement with cold in-place recycling mixtures

The cold in-place recycling (CIR) technique has been gradually accepted and applied in multiple areas of China as the lower layer of highway pavement. The overall pavement typically shows satisfactory resistance to permanent deformations. The objective of this research is to evaluate the high-temperature performance of a typical China pavement structure with CIR. Since the conventional creep test cannot adequately simulate the field conditions, an Advanced Cyclic Creep Test, which can replicate in the laboratory stresses and temperatures encountered in the field was developed and utilised to study the resistance of the CIR pavement to high-temperature deformations. Creep curves following three-stage creep models best fits were obtained to study the effects of cement contents (1.5%, 2.0%, 2.5%) in CIR mixtures and anti-rutting agent in the middle layer on the high-temperature performance of the composite specimens under different testing conditions. In the process of specimen preparation, the impact of the middle-layer compaction on the CIR mixtures was also quantified. According to the results of this research, 6 days of curing time is recommended to restrict the effect of paving and rolling of the hot mix asphalt (HMA) on top of the CIR layer. Adding 0.3% anti-rutting agent to the HMA in the middle layer can enhance the resistance of the composite specimen to high-temperature deformations. An increase in cement content of the CIR mixtures from 1.5% to 2.0% can improve the high-temperature performance of the CIR pavement. Comparing with newly constructed pavement, it is verified that the typical China highways pavement structure including CIR shows satisfactory high-temperature performance.

Influence of Anti-Rutting Agent on the Pavement Performance of Asphalt Mixture

With the increase of traffic volume and axle load, asphalt pavement rutting has become one of the major damage of highway. Adding anti-rutting agent in asphalt mixture is a kind of effective mean to prevent pavement rutting. In this paper, RA anti-rutting agent is selected as the admixture. Laboratory test is taken to study the pavement performance of asphalt mixture and analyze the influence of anti-rutting agent on the pavement performance of asphalt mixture.

Experiment Study of Influence Factors on High-Temperature Stability of Closely Gap-Graded Bituminous Mixture

Rutting in asphalt pavements continues to create problems for pavement. The aim of this study was to analyze the influence of different gradation composition, asphalt dosage, temperature and dosage of anti-rutting agent on high-temperature stability of cosely gap-graded bituminous mixture. To achieve this objective, 171 different rutting specimens using different mix parameters were analyzed for their the high-temperature stability. The mix parameters include: three types of aggregate gradation, five types of asphalt dosage, four types of temperature and five types of anti-rutting agent dosage. Study results indicate that adding proper content of coarse aggregate can play occluding and wedging role in aggregate mixture. The optimal bituminous dosage in rutting test are lower 0.1%~0.3% than that in Marshell test. At 65°C, the high-temperature stability of the cosely gap-graded bituminous mixture is not able to meet the requirement of standards. The optimal dosage of anti-rutting agent are equal to 0.3% in case of no increasing bituminous dosage.