SBS Modified Asphalt Mixture Research Articles

Fatigue Properties of Rubber Modified SMA Asphalt Mixture

To evaluate fatigue propertiesof rubber modified SMA asphaltmixture, based on optimizing the preparation process of rubber asphalt, the splitting fatigue testsof three kinds of asphalt mixture is carried out including ordinary asphalt, modified asphalt with rubber powder and SBS modified asphalt. And the freezing and thawing conditions were considered in the tests. The results show that rubber powder can improve the fatigue properties of SMA asphalt mixture, but the modified effect of rubber powder is not as good as SBS modifier, the fatigue properties of asphalt mixture are deteriorated by freeze-thaw conditions, the deterioration degree of rubber modified asphalt mixture is less than SBS modified asphalt mixture, but rubber modified asphalt mixture has better freeze-thaw durability.

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.

Pavement performance of environmentally friendly asphalt modifier in hot and humid environment

The modified asphalt binders and mixtures were prepared by SBP directed vat set modifier with recycled polyethylene as the main component. The effect of SBP modifier on the high-temperature characteristics of asphalt was characterized and analyzed by dynamic shear rheometer and differential scanning calorimeter. Thus, the pavement performance of SBP modified asphalt mixture was evaluated, and the test road was paved. The results show that the high-temperature rheological characteristics of asphalt were significantly improved with the SBP modifier. The high-temperature performance grade (PG) can be increased by 2-3 classes, but the improvement in high-temperature sensitivity was not noticeable. The SBP modifier can improve the low-temperature performance of asphalt to a certain degree, but this is not enough to change the low-temperature performance grade of asphalt. The high-temperature and water stability of SBP modified asphalt mixture are better than that of SBS modified asphalt mixture, which is more suitable for high-temperature and rainy areas.

Laboratory performances of nano-particles/polymer modified asphalt mixtures developed for the region with hot summer and cold winter and field evaluation

In some regions with hot summer and cold winter, most modified asphalt mixtures cannot meet the requirement of high-temperature stability and low-temperature cracking resistance simultaneously very well, so rutting or cracking often occurs in these regions. This paper tries to use nano-CaCO3/SBR (Styrene butadiene rubber) and nano-ZnO/TiO2/SBS (Styrene–butadiene–styrene) composite modified asphalt mixtures to solve this problem. The properties of these two asphalt mixtures were compared with those of base, SBR modified and SBS modified asphalt mixtures through rutting, beam bending, immersion Marshall, freeze–thaw splitting, three-point bending fatigue and splitting tests. Results show that the high-temperature stability of nano-CaCO3/SBR composite modified asphalt mixture is better than that of SBR modified asphalt mixture, and their low-temperature cracking resistances are close. In addition, the water stability, fatigue performance, performance after ageing, and splitting strength of SBR modified asphalt mixture can be improved by the addition of nano-CaCO3. All of the performances mentioned above of nano-ZnO/TiO2/SBS composite modified asphalt mixture are better than those of base or SBS modified asphalt mixture. In summary, nano-CaCO3/SBR or nano-ZnO/TiO2/SBS composite modified asphalt mixture has good high-temperature stability and low-temperature cracking resistance and can be used in the regions with hot summer and cold winter.

Static and dynamic mechanical properties of warm mixed asphalt mixture before and after aging

In order to study the effect of warm mix agent on the mechanical properties of warm mix asphalt mixture before and after aging, this article uses the uniaxial compression test and the uniaxial dynamic modulus test which were carried out on the unaged, short-term aging and long-term aging conditions of the matrix and SBS modified asphalt mixture mixed with RH and Evotherm warm mix agent respectively. The results show: the performance of each asphalt mixture at low temperature and high frequency is equivalent, indicating that dynamic mechanics is not suitable for evaluating the low temperature performance of asphalt mixture; high temperature and low frequency can be used as an evaluation index for high temperature anti-rutting of asphalt mixture. By analyzing the rebound modulus, uniaxial dynamic modulus and other results, it shows that the addition of the warm mix agent improves the low temperature performance of the asphalt mixture, alleviates the aging of the asphalt mixture, and the aging of the aging also brings about a decrease in high temperature stability. The beneficial effect of the Evotherm is weak, and the low temperature performance of the asphalt mixture after aging and the high temperature stability of the warm asphalt mixture after long-term aging are improved. From the comprehensive analysis of static and dynamic mechanical properties, the elastic modulus and dynamic modulus of asphalt mixture are not much different, and the dynamic static modulus of the mixture after aging is quite different, which provides a theoretical basis for the dynamic and static modulus transformation.

The effect of nano-CaCO3/styrene–butadiene rubber (SBR) on fundamental characteristic of hot mix asphalt

This study investigates the performance characteristics of nano-CaCO3/SBR-modified asphalt mixture. SBR-modified asphalt was mixed with nano-CaCO3 particles at a concentration of 3%, 4%, 5%, 6% and 7% by weight of asphalt binder. Wheel track test was used to determine the proper dosage of nano-compound modifiers which are comparable to SBS-modified asphalt mixture in terms of deformation performance at high temperature. Asphalt mixture performance tests such as static creep test, overlay test and three-point beam bending test were conducted for nano-modified asphalt mixture and SBS-modified asphalt mixture. The micro topography and micromechanical property of modified bitumen are evaluated by atomic force microscopy (AFM) to study the modification mechanism of nano modifiers. Results show that 5%CaCO3/4%SBR-modified asphalt mixture has superior rutting resistance and creep characteristics at high temperature in terms of wheel track test and static creep test. However, reflection cracking resistance and flexural deformation stability of 5%CaCO3/SBR-modified asphalt mixture at low temperature are slightly worse than SBS-modified asphalt mixture. Despite this, ANOVA result indicates that the difference between the two kinds of asphalt mixture is not significant. AFM test result reveals that 5%CaCO3/SBR modifier can well be dispersed in bitumen and evidently increase the micromechanical properties of bitumen such as adhesion and dissipated energy while it has a negative effect on Derjaguin–Muller–Toporov (DMT) modulus. In general, 5%nano-CaCO3/4%SBR modifier has the desirable potential to comprehensively improve the performance of hot mix asphalt and is promised to be applied in the warm area.

Effect of volcanic ash filler on thermal viscoelastic property of SBS modified asphalt mastic

In this study, the effect of volcanic ash (VA) fine filler and SBS modifier on the thermal stability of asphalt mastics was investigated. Firstly, the micromorphology, porosity and particle properties of VAs were characterized with Scanning Electron Microscopy (SEM), N2 adsorption tests and Laser Particle Size Analyzer (LPSA), respectively. Secondly, frequency sweeping Dynamic Shear Rheometer (DSR) tests on mastics at −20 °C and 60 °C and three-point bending tests on mixes at −10 °C were conducted. The viscoelastic properties of the mastics were analyzed with the aid of linear viscoelastic (LVE) element models. It was found that the modification of asphalt by SBS was the dominant factor for improving the high- and low-temperature performance of mastics. Furthermore, VA filler can further enhance the mechanical properties of SBS modified asphalt mixture via a solid filler-SBS-binder system formed within mastics due to the complex topography and porous structure of VA.

Design Optimization of SBS-Modified Asphalt Mixture Reinforced with Eco-Friendly Basalt Fiber Based on Response Surface Methodology.

This paper investigates the effects of basalt fiber content, length and asphalt-aggregate ratio on the volumetric and strength properties of styrene-butadiene-styrene (SBS)-modified asphalt mixture reinforced with eco-friendly basalt fiber. An experimental scheme was designed to optimize three preparation parameters for the Marshall test indices based on response surface methodology (RSM). The results showed that basalt fiber content presents a more significant effect on air voids, voids in mineral aggregates and voids filled with asphalt. Basalt fiber length is more related to Marshall stability, and flow value exhibits a significant variation trend with asphalt-aggregate ratio. The optimization of preparation parameters is determined as follows: basalt fiber content is 0.34%, length is 6 mm, asphalt-aggregate ratio is 6.57%, which possesses favorable and reliable accuracy compared with experimental results. Furthermore, basalt fiber reinforced asphalt binder and mixture were also studied, and it was found that basalt fiber can enhance the performance of asphalt binder and mixture in terms of cone penetration, softening point, force ductility, as well as pavement performance tests.

Study on Performance of Composite Flame-retardant Asphalt Material in Tunel

In order to study the pavement performance of flame-retardant asphalt mixture, firstly, three kinds of compound flame-retardant modified asphalt, 3%, 6% and 9%, were prepared by high speed shearing method. The optimum dosage of composite flame retardant material was selected through segregation test, oxygen index test and smoke density test. Secondly, the road performance of asphalt mixture was analyzed by rutting test, low temperature splitting test and freezing thawing splitting test system. The results show that when the dosage of flame-retardant composites is 6%, the segregation degree of SBS modified asphalt mixture is the minimum, and it can effectively improve the flame retardant effect and smoke suppression effect of SBS modified asphalt. The high temperature stability and the low temperature crack resistance of the 6% composite flame retardant asphalt mixture have been improved, while water stability has not been much affected.

Study on road performances of asphalt mixtures with granulated polymer anti-rutting additive

ABSTRACTRutting has been one of the primary concerns for highway engineers in China. Granulated polymer anti-rutting additive may be an effective way to solve this problem. However, it is difficult to find previous research on the application of granulated polymer as an anti-rutting additive in different types of asphalt mixtures. This research aims to investigate the influences of the anti-rutting additive contents on road performances based on different types of asphalt mixtures, and also explores potential reasons for road performance improvement. Three types of asphalt mixtures: dense-graded asphalt concrete (DG-AC), dense-graded Superpave (DG-Superpave)，semi-open-graded asphalt macadam (SOG-AM), were included. Road performances, including high-temperature performance, low-temperature performance and moisture susceptibility, were studied at three anti-rutting additive percentages: 0.2, 0.3 and 0.4% weight of the asphalt mixture. The mixtures without the anti-rutting additive were regarded as control groups. In order to better analyse the road performance improvements, the properties of modified asphalt with 0.4% anti-rutting additive were studied, as well as the anti-rutting additive physical form in the asphalt mixture. It was found that the anti-rutting additive improved mixture’s high-temperature performance significantly while its effects on low-temperature performance were not so. It reduced low-temperature tensile strain within 12.9% range. Moisture susceptibility was improved greatly after adding 0.2% anti-rutting additive as compared to the corresponding control groups. By increasing the additive contents to 0.3 and 0.4%, the moisture susceptibility had no significant difference compared with that of the 0.2% additive content group. Road performance improvements may relate to the combined action of reinforcement and gap filling by the elongated anti-rutting additive, as well as asphalt modification within short time. When the additive content is no more than 0.3%, the materials costs of the additive-modified asphalt mixtures are less than that of SBS-modified asphalt mixtures.

Understanding the low temperature properties of Terminal Blend hybrid asphalt through chemical and thermal analysis methods

Terminal Blend (TB) hybrid asphalt binders are composed of crumb rubber, SBS polymer and polyphosphoric acid (PPA). Understanding the relationship between the chemical composition and low temperature properties has a guiding significance for asphalt modification. In this study, BBR (Bending Beam Rheometer) test, GPC (Gel Permeation Chromatography) test, FTIR (Fourier Transform Infrared) test and DSC (Differential Scanning Calorimetry) test were used to evaluate the rheological and chemical properties of TB hybrid binder and TSRST (Thermal Stress Restrained Specimen test) was conducted to estimate the low temperature properties of mixture. The results indicated that crumb rubber and SBS improved low temperature properties, while PPA had an adverse effect. Furthermore, during the degradation of crumb rubber, aliphatic component was released, which played an important role in improving low temperature properties. Finally, TB hybrid asphalt mixture also had better low temperature properties than SBS modified asphalt mixtures according to TSRST results.

Effect of Different Media Aqueous Solution on Road Performance of Asphalt Mixtures

Servicing in the natural environment, asphalt pavement is often exposed to the various aqueous solution, however, the effect of different media aqueous solution on road performance of asphalt mixtures remains ambiguous. In this study, the influences of water, acid, alkali and salt solution on volume of air voids (VV), tensile strength rate (TSR), low temperature performance of 70# asphalt mixtures and SBS modified asphalt mixtures were investigated through freeze-thaw cycles test, void ratio test, Lottman test and Three-point Bending Fracture (TBF) test. The results indicated that freeze–thaw cycles influenced the road performance of asphalt mixtures significantly, increased the air void of asphalt mixtures, and reduced tensile strength ratio and failure strain of asphalt mixtures. Compared with the distilled water, the damage of acid, alkali and salt solution on the road performances of asphalt mixtures were more serious, especially alkali solution to tensile strength rate and failure strains in low temperature, and salt solution to VV. The moisture corrosion resistance of SBS modified asphalt mixtures is better than that of 70# asphalt mixtures.

Effect of material composition on antistripping performance of SBS modified asphalt mixture under dry and wet conditions

Styrene-butadiene-styrene (SBS) modified asphalt used in road engineering is a complicated mixture of various compositions. The present study was undertaken to evaluate the influence of different raw materials and their content on the moisture stability of SBS copolymer modified asphalt mixture. A total of 18 different combinations of base asphalt, SBS, furfural extract oil (FEO), and stabilizer were considered to prepare different SBS modified asphalt samples, and the contact angle test was carried out to determine the work of adhesion and the work of debonding of SBS modified asphalt with aggregate. Moreover, a multi-factor Analysis of Variance (ANOVA) was conducted to investigate the statistical effects of the material composition factors. The results show that the bond strength between SBS modified asphalt and aggregate is significantly affected by the source of base asphalt, but it is insensitive to the change of SBS type under dry and wet conditions. Besides, the moisture damage resistance of SBS modified asphalt improves firstly and then reduces with the rising storage of SBS, FEO, and stabilizer. Furthermore, linear regression analysis suggests that the work of adhesion under dry condition has excellent correlation with the work of debonding under wet condition.

Impact of the Superpave hot mix asphalt properties on its permanent deformation behavior

In Iraq, the severity of rutting has increased in asphalt pavements possibly due to the increase in truck axle loads, tyre pressure, and high pavement temperature in summer. As of late, Superpave has been accounted as an enhanced system for performance based design, analysis of asphalt pavement performance prediction for asphalt concrete mixes. In this research the development of permanent deformation in asphalt concrete under repeated loadings was investigated, Wheel-Tracking apparatus has been used in a factorial testing program during which 44 slab samples were tested to simulate actual pavement. The objectives of the present research include; investigating the main factors affecting rutting in asphalt concrete mixture, quantifying the effect of SBS polymer and steel reinforcement on asphalt concrete mixtures in addition to studying the effect of variables on the asphalt concrete mixes against moisture sensitivity. It has been determined that that increasing of compaction temperature from 110 to 150°C will decrease the permanent deformation by 20.5 and 15.6 percent for coarse and fine gradation control asphalt mixtures, respectively. While the permanent deformation decreases by 21.3 percent when the compaction temperature is increased from 110 to 150°C for coarse gradation SBS modified asphalt mixtures.

A lab study to develop a bridge deck pavement using bisphenol A unsaturated polyester resin modified asphalt mixture

To improve the low-temperature and anti-fatigue performances of the bridge deck pavement and decrease its cost, an unsaturated polyester resin (UPR) modified asphalt mixture is put forward in this paper. First the optimum formula of UPR modified asphalt is determined through several tests. Second the ductility, bending beam rheometer (BBR), dynamic shear rheometer (DSR) and tensile tests are conducted for matrix asphalt, and SBS, epoxy and UPR modified asphalts. Finally, Marshall, rutting, low temperature bending, freeze-thaw splitting and fatigue tests are conducted for their mixtures. Test results show that the laboratory performances of UPR modified asphalt mixture are more excellent than those of SBS modified asphalt mixture and have advantages over those of epoxy modified asphalt mixture in low-temperature crack resistance, water stability and anti-fatigue ability. The maximum flexural-tensile strain, stripping inflectionpoint and fatigue life of UPR modified asphalt mixture are 2.54, 1.25 and 1.08 times of those of epoxy modified asphalt mixture, respectively. Whereas the cost of UPR modified asphalt is only 62% of that of epoxy modified asphalt. Although the BPA will have a certain impact on the health of BPA unsaturated polyester resins production workers and construction workers, this impact can be controlled by limiting BPA concentrations within reasonable ranges and taking effective protective measures.

Performances evaluation of epoxy asphalt mixture containing snow-melting agent

The performance degradation of the asphalt mixture blended with the snow-melting agent can inevitably occur although it can be relieved by adding the high viscosity modifier or Nanopowder. The thermosetting epoxy asphalt binder, different from the conventional thermoplastic asphalt as SBS modified asphalt, was adopted in this research to solve this problem. Experiments were carried out to test the road engineering performances, conductivity, deicing and snow melting performances of epoxy asphalt mixture with the snow-melting agent content of 6%, 7% and 8%, substituting the equivalent amount of mineral filler, and then the results were compared with SBS modified asphalt mixture. The results show that snow-melting agent has a slight influence on the engineering performance of epoxy asphalt mixture. With snow-melting agent content or environmental temperature rising, the snow-melting agent release amount and rate of epoxy asphalt mixture increase, but are lower than those of SBS modified asphalt mixture under the same condition. The epoxy asphalt mixture with snow-melting agent can provide preferable snow melting performance and low ice adhesion. This thermosetting mixture with snow-melting agent possesses engineering application potential due to its excellent performance and long snow melting life.

Investigation of influence factors on low temperature properties of SBS modified asphalt

Styrene-butadiene-styrene (SBS) is widely used in asphalt modification and the investigations about SBS modified asphalt are focused on high temperature property, storage stability and the compatibility between SBS and asphalt. While the study on influencing factors on low temperature properties are not sufficient yet. In this paper, a systematical research was conducted to evaluate the influencing level of important factors such as SBS polymer type, SBS content, sulfur content and addition of rubber processing oil. Firstly, bending beam rheometer (BBR) test associated with Burger’s model was used to evaluate the low temperature property and relaxation capacity. Furthermore, FTIR, GPC and DSC tests were conducted to investigate the chemical changes in SBS modified asphalt. At last, the low temperature performance of SBS modified asphalt mixture was investigated with thermal stress restrained specimen test (TSRST). In this paper, the optimum modification scheme of SBS modified asphalt binder and mixture was investigated and summarized. SBS polymer is swollen by saturates and aromatics which made the base binder lack of maltene fraction. While the further addition of rubber processing oil supplemented the maltenes which improved the low temperature property.

Revised Penetration Method Based on Evaluate High Temperature Property of SBS Modified Asphalt

In order to achieve the penetration method which could reflect the high temperature property of SBS modified asphalt, the paper presented the penetration test of SBS modified asphalt with different types and dosages of SBS modifier at three kinds of penetration weight and four different temperatures. Meanwhile, the high temperature performance of the SBS modified asphalt mixture was studied. It was found that penetration measured under current specification method (25oC, 100g, 5s) could not identify the difference of viscosity and high temperature property of different SBS modified asphalt. When the test conditions are revised to “penetration weight of 150 g, test temperature of 30oC, penetration time of 5s”, the penetration of different SBS modified asphalt measured by revised method could be used to evaluate the temperature susceptibility of SBS modified asphalt accurately and are closely related to the dynamic stability of mixture.

Study on road performance of prefabricated rollable asphalt mixture

A new road repair idea has been provided by prefabricated rollable asphalt pavement (Rollpave). In order to meet the need for long-term road performance and special construction technology for Rollpave, an appropriative rollable modified asphalt (RMA) has been developed and used. The road performance of RMA-modified asphalt is tested firstly by three indicators test, and compared with the virgin asphalt and styrene - butadiene - styrene (SBS)-modified asphalt. Then the composition of prefabricated rollable asphalt mixture is designed by modified Marshall test method, and the road performance of prefabricated rollable asphalt mixture is studied by wheel tracking test, −10°C/10°C bending test and immersion Marshall test. Finally, the test section is paved by using prefabricated rollable asphalt pavement. The results showed that the high-temperature properties as well as low-temperature properties and water stability of RMA-modified asphalt mixture are better than that of virgin asphalt mixture and SBS-modified asphalt mixture, and the rollability and road performance of prefabricated rollable asphalt pavement are verified initially by paving the test section.

Crack and crack growth behavior analysis of asphalt mixtures based on the digital speckle correlation method

Cracking is one of the main reasons for asphalt pavement damage. Because of the anisotropism of asphalt mixtures, traditional experimental methods cannot analyze displacement and strain fields accurately. A full-field, noncontact measurement technology—the digital speckle correlation method (DSCM)—is a good method to analyze the deformation characteristics of asphalt mixtures. By using DSCM and a semi-circular bending (SCB) test, the crack initiation and propagation rules can be tested experimentally; the full-field displacement and strain can be analyzed by vic-3D software. The results show that the strain field (Exx) and the rate of change displacement field (dU/dt) are well suited to study the properties of crack and fracture characteristics of asphalt mixtures. The interface between asphalt binder and stone is the weakest part of the entire structure, and comparing the crack growth rate and load displacement curve of a crumb-rubber (CR) modified asphalt mixtures and a styrene-butadienestyrene (SBS) modified asphalt mixtures, it is found that the carrying capacity of a CR modified asphalt mixtures is stronger than that of a SBS modified asphalt mixtures.