Properties Of SBS Research Articles

Study on viscoelastic properties and rheological properties of SBS modified asphalt for road use with service life

SBS modified asphalt is an important material in the construction of high-grade highway, and its performance changes directly affect the pavement performance. In this study, SBS modified asphalt was extracted from the actual pavement with different service years, and the rheological properties of SBS modified asphalt with different service years were studied by macroscopic test and microscopic molecular dynamics simulation. The macroscopic test results show that the needle penetration value of SBS modified asphalt increases by 50.6% after two years of service, and the viscosity of SBS modified asphalt increases by 54.8% after 12 years of service. With the increase of service life, G* and G’’ of SBS modified asphalt showed an increasing trend, and δ and G’’/G’ showed a decreasing trend. The molecular dynamics simulation results of SBS modified asphalt were consistent with the macroscopic experimental results. The rheological properties of SBS modified asphalt showed a decreasing trend with the service life, and the interfacial energies between SBS modified asphalt and aggregate also showed a decreasing trend. The research in this paper will provide a theoretical basis for the future study of the deterioration law of SBS modified asphalt and the formulation of road maintenance plan.

Simulation and investigation of the mild-moderate aging properties of SBS modified bitumen: Physical, microscopic and rheological properties

Styrene-butadiene-styrene block copolymer (SBS) modified bitumen (SMB) is unable to meet usage requirements after being exposed to sun-light, heat and oxygen. The researches show that it is difficult to restore bitumen effectively when the penetration of the aged bitumen is below 20 dmm. Therefore, the penetration of 20 dmm is taken as the dividing line in this paper. Higher than 20 dmm is considered as mild-moderate aging, while lower than 20 dmm is considered as severe aging. The traditional rotating thin-film ovens (RTFO) and pressure aging vessels (PAV) methods are similar to simulate the aging behavior of the upper layer of bitumen pavement, but they are difficult to simulate the aging in the depth direction of bitumen pavement. In this paper, the aging of the modified bitumen is simulated by extending the aging time and deepening the depth of the aging mold, and then it is graded according to the penetration. We aimed to investigate the differences in physical, microscopic and rheological properties of SMB with including 0 wt%, 1.5 wt%, 2.5 wt%, 3.5 wt%, 4.5 wt% and 5.5 wt% SBS content before and after aging. Through the physical performance, such as penetration, softening point, ductility and elastic recovery, it was observed that a high SBS content leads to strong anti-aging ability. Fourier Transform Infrared (FTIR), fluorescence microscopy (FM), scanning electron microscopy (SEM) and atomic-force microscope (AFM) revealed that a good network structure can be formed through absorbing light components when the SBS exceeds 3.5 wt%. After that, it was found that there is a positive correlation between aromatic index and penetration, as well as a positive correlation between butadiene index and softening point. Additionally, rheological frequency scanning and temperature scanning indicated that the modulus was increased and the phase angle was decreased with increasing SBS content or aging. After aging, the rutting resistance of SMB was enhanced but the cracking resistance was weakened. This research can establish a theoretical support and foundation for the regeneration of the mild-moderate aged SMB.

UV aging resistance improvement of SBS modified asphalt binder by organic layered double hydroxide and naphthenic oil: Its preparation, properties and mechanism

To enhance the UV aging resistance of SBS modified asphalt, LDHs and naphthenic oil were selected to modify it compositely. Firstly, organic treatment for LDHs was carried out through the combination of surface modification method and intercalation modification method to improve its compatibility with asphalt, and effectiveness of organic treatment was evaluated through the microscopic testing methods. Then, organic LDHs/SBS modified asphalt binders were developed by melt blending method, on this basis, appropriate naphthenic oil was added for composite modification. Subsequently, the conventional physical properties, storage stability and rheological properties tests were carried out to evaluate the comprehensive properties of the prepared modified asphalt containing LDHs and naphthenic oil. On this basis, TOPSIS method was conducted for multi-index optimization to determine the optimal dosages of LDHs and naphthenic oil. Finally, UV aging resistance of the developed modified asphalt was also evaluated, and reaction mechanism was explored with FTIR and FM. Test results show that stearic acid (SA) was successfully absorbed on the surface of LDHs, and -SO32- in ultraviolet light absorber (UVT) has successfully entered the interlayer galleries of LDHs, thus achieving the organic treatment for LDHs. Organic LDHs can significantly improve the high temperature properties and storage stability of SBS modified asphalt, and naphthenic oil can also improve the storage stability of SBS modified asphalt at the proper dosage. In addition, the two modifiers can both effectively improve the UV aging resistance of SBS modified asphalt. Based on the multi-index optimization results, it is recommended that the optimal dosages of LDHs and naphthenic oil are 2 % and 2.5 %, respectively, and at this conditions, comprehensive properties of the prepared modified asphalt can achieve the best. Microstructure characterization tests results reveal that LDHs and naphthenic oil are only simply dispersed in asphalt and do not cause the structural damage of SBS modified asphalt. Meanwhile, the special layered structure of LDHs can hinder the mobility of asphalt molecular chains, which enhances the interaction force between asphalt molecular chains and SBS modifier molecular chains, thus improving the road properties of SBS modified asphalt.

Study on the Performance of Asphalt Modified with Bio-Oil, SBS and the Crumb Rubber Particle Size Ratio.

To enhance the properties of SBS and crumb rubber-modified asphalts, four different amounts (5%, 10%, 15%, and 20%) of castor oil were added to crumb rubber-modified asphalts to mitigate the adverse effects of high levels of fine crumb rubber particles on the aging resistance of SBS and crumb rubber-modified asphalt. Initially, a conventional test was conducted to assess the preliminary effects of bio-oil on the high-temperature and anti-aging properties of SBS and crumb rubber-modified asphalt. Subsequently, dynamic shear rheometer and bending beam rheometer tests were employed to evaluate the impact of bio-oil on the high- and low-temperature and anti-fatigue properties of SBS and crumb rubber-modified asphalt. Finally, fluorescence microscopy and Fourier transform infrared spectroscopy were used to examine the micro-dispersion state of the modifier and functional groups in bio-oil, SBS and crumb rubber composite-modified asphalts. The experimental results indicated that bio-oil increased the penetration of SBS and crumb rubber-modified asphalt, decreased the softening point and viscosity, and significantly improved its aging resistance. The addition of bio-oil enhanced the anti-fatigue properties of SBS and crumb rubber-modified asphalt. The optimal amount of added bio-oil was identified. Bio-oil also positively influenced the low-temperature properties of SBS and crumb rubber-modified asphalt. Although the addition of bio-oil had some adverse effects on the asphalt's high-temperature properties, the asphalt mixture modified with bio-oil, SBS, and crumb rubber still exhibited superior high-temperature properties compared to unmodified asphalt. Furthermore, fluorescence microscopy and Fourier transform infrared spectroscopy results demonstrated that bio-oil can be uniformly dispersed in asphalt, forming a more uniform cross-linked structure and thereby enhancing the aging resistance of SBS and crumb rubber-modified asphalt. The modification process involved the physical blending of bio-oil, SBS, and crumb rubber within the asphalt. Comprehensive research confirmed that the addition of bio-oil has a significant and positive role in enhancing the properties of SBS and crumb rubber-modified asphalt with different composite crumb rubber particle size ratios.

Investigation of Rheological and Physical Properties of SBS and WCO Composite Modified Bitumen

Nowadays, the use of waste materials in various industries is becoming widespread in order to promote waste recycling. Thus, scientists are researching the use of waste materials in bitumen modification. In this study, it was aimed to investigate the effect of waste cooking oil (WCO) on the physical and rheological properties of unaged Styrene-Butadiene-Styrene modified bitumen (SBSMB) by adding WCO at different ratios (1, 3, 5, 7, and 9%) to SBS modified bitumen. Accordingly, rotational viscosity (RV) tests and rheological tests with dynamic shear rheometer (DSR) based on the determination of complex shear modulus (|G*|) and phase angle (δ) were conducted along with the traditional bitumen tests. As a result of the experimental study, it was observed that adding WCO increased the workability and fatigue resistance of SBSMB, however, decreased its rutting resistance. Therefore, the mixing and compaction temperatures of SBSMB can be decreased by adding low amounts of WCO without excessive performance loss. Thus, during the construction of asphalt pavements, environmental damage can be reduced by utilizing waste materials and reducing CO2 emissions.

Study on the influencing factors of mechanical properties of anti-icing modified asphalt mortar

Accumulated snow and ice on road surface affect traffic operation. Anti-icing asphalt pavement is widely implemented as an active snow melting technology. However, there are few studies on anti-icing modified asphalt mortar mechanical properties and the effect of mortar materials on the interaction between modified asphalt and anti-icing filler. For this reason, this study investigated the mechanical properties of asphalt including rheological, high-temperature, fatigue and low-temperature properties through frequency and temperature scan, multiple stress creep recovery, linear amplitude scan, and single edge notched beam test. Based on this, the significant factors affecting asphalt mechanical properties were identified by analysis of variance. Subsequently, the Palierne-C-G* parameter was used to quantify the interaction between modified asphalt and anti-icing filler, and the effect of asphalt chemical structure on the interaction was revealed by Fourier Transform Infrared Spectroscopy (FTIR) test. The results indicated that the anti-icing filler significantly improved the high temperature and fatigue resistance of asphalt. Compared with SBS modified asphalt mortar, the mechanical properties of composite modified asphalt mortar were superior. The most significant factor affecting the mechanical properties of SBS modified asphalt mortar was modifier dosage, while the most significant factor affecting the composite modified asphalt mortar was crushed rubber dosage. The interaction showed a decreasing trend with the increase of frequency, while it appeared to increase and then decrease with the increase of temperature. The carbonyl functional group of asphalt correlated best with the interaction between asphalt and filler.

Effect of acylhydrazone self-healing agents with different structures on the properties of SBS modified asphalt waterproofing membrane

To prepare SBS modified asphalt (SMA) waterproofing membrane with excellent self-healing performance, in this paper, four self-healing agents (ASHA-A, ASHA-B, ASHA-C, ASHA-D) with acylhydrazone bonds and carbon-carbon double bonds (CC) were synthesized, and were used to prepare self-healing SMA waterproofing membranes (SSMA-A, SSMA-B, SSMA-C, SSMA-D). The effects of ASHAs with different structures on the structure, high and low temperature properties, joint peel strength and self-healing performance of SSMAs were investigated. The Fourier transform infrared spectroscopy and fluorescence microscope results showed that acylhydrazone bonds of ASHAs were introduced into the chains of SBS molecules, and the SBS in SSMAs occurred crosslinking through the CC of ASHAs and SBS, the crosslinked network structures of SBS in SSMA-C and SSMA-D were denser and more complete because ASHA-C and ASHA-D contained more CC involved in the crosslinking reaction. The softening point and low temperature flexibility of SSMAs were enhanced by the formation of the SBS crosslinked network structure, and the optimum dosage of ASHAs was 0.6%. The joint peel strength of SSMA-A, SSMA-B, SSMA-C and SSMA-D increased by 26.68%, 31.25%, 49.52% and 56.97% compared to SMA. The introduction of acylhydrazone bonds with reversible fracture and rearrangement significantly improved the crack self-healing performance of SMA, the impermeability times of SMA, SSMA-A, SSMA-B, SSMA-C and SSMA-D were 13.28 min, 37.29 min, 42.53 min, 53.34 min and 59.67 min after self-healing at 40℃ for 8 h, which indicated that ASHA-D with benzene ring and multiple CC had the best improvement in self-healing performance of SMA.

Effect of synchronous surface grafting and intercalation bentonite on properties of SBS modified bitumen

To better enhance the improvement effect of natural bentonite on the comprehensive performance of styrene-butadiene-styrene thermoplastic elastomer modified bitumen (SMB), in this study, 3-(trimethoxysilopropyl) dimethyl octadecyl ammonium chloride (DC5700) was used for synchronous surface grafting and intercalation of bentonite (DC5700-Bentonite). Meanwhile, γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) surface grafting bentonite (KH560-Bentonite) and octadecyldimethylbenzylammonium chloride (ODBA) intercalation bentonite (ODBA-Bentonite) were used as comparison samples. The structure and properties of the bentonite and organic bentonites (DC5700-Bentonite, KH560-Bentonite and ODBA-Bentonite) were tested by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), ultraviolet-visible spectrometer and contact angle measurement. The effects of bentonite and organic bentonites on physical, rheological and aging properties of SMB were investigated. FTIR and XRD results showed that KH560 was chemically grafted onto the surface of bentonite, ODBA was organically intercalated into the bentonite, while DC5700 achieved synchronous surface grafting and intercalation on the bentonite. Compared with KH560-Bentonite and ODBA-Bentonite, DC5700-Bentonite had the best lipophilicity and ultraviolet shielding ability. When the bentonite content was 4 wt%, KH560-Bentonite, ODBA-Bentonite and DC5700-Bentonite could increase the rutting factor of SMB by 2.9 ℃, 4.9 ℃ and 6.5 ℃, respectively, and reduce the ductility of SMB by 6.5 cm, 4.2 cm and 3.1 cm. Meanwhile, compared to SMBs containing KH560-Bentonite or ODBA-Bentonite, the SMB containing DC5700-Bentonite had the smallest creep stiffness at − 12 ℃, − 18 ℃, and − 24 ℃. The results indicated that DC5700-Bentonite was more conducive to increasing high-temperature performance of SMB than KH560-Bentonite and ODBA-Bentonite, and its adverse effects on low-temperature ductility and low-temperature cracking resistance of SMB were also significantly reduced. After thermal and ultraviolet aging, the deterioration extent of physical and rheological properties of SMB containing DC5700-Bentonite was significantly smaller than that of SMB containing KH560-Bentonite and ODBA-Bentonite. FTIR revealed that DC5700-Bentonite was more beneficial than KH560-Bentonite and ODBA-Bentonite in inhibiting the increase of carbonyl index and the decrease of butadiene index in SMB during aging. The comprehensive results revealed that compared to KH560 surface grafting bentonite and ODBA intercalation bentonite, DC5700 synchronous surface grafting and intercalation bentonite were more conducive to improving the physical and rheological properties, and aging resistance of SMB.

Effects of solvent-free bentonite fluid on physical, rheological and aging properties of SBS modified bitumen

Layered silicate materials were often used for bitumen modification, but their improvement effect on bitumen performance was limited due to their poor compatibility with bitumen. Introducing long-chain organic compounds on the surface of inorganic materials can make them exhibit solvent-free fluid characteristics, which can significantly enhance the compatibility between inorganic and organic materials. In this study, 3-(trimethoxysilyl propyl) dimethyl octadecyl ammonium chloride (DC5700) and nonylphenol polyoxyethylene ether sodium sulfate (NPES) were used to organically treat bentonite (Ben) to prepare solvent-free bentonite fluid (Ben-fluid) so as to effectively improve the overall performance of styrene-butadiene-styrene copolymer (SBS) modified bitumen (SMB). Ben and DC5700 organically treated bentonite (DC5700-Ben) were used as comparative samples. The microstructure, ultraviolet reflectance and lipophilicity of Ben, DC5700-Ben and Ben-fluid as well as fluidization characteristics of Ben-fluid were tested and characterized. The results of X-ray diffraction spectrometer and Fourier transform infrared spectrometer (FTIR) demonstrated that DC5700 intercalated into the layers of the Ben and chemically grafted on the Ben surface, and the NPES was anchored on DC5700 molecules through ionic bonds. Compared with Ben and DC5700-Ben, Ben-fluid had the highest ultraviolet reflectance and the best lipophilicity. As the temperature exceeded 82.3 ℃, the fluidization characteristics of Ben-fluid began to appear. Meanwhile, the effects of Ben-fluid on physical, rheological and aging properties of SMB were investigated. Ben-fluid was more conducive to enhance the high-temperature stability of SMB than Ben and DC5700-Ben, and has less adverse effects on the low-temperature physical and rheological properties. The aging results of different SMBs revealed that the change in physical properties of SMB containing Ben-fluid after thermal and ultraviolet aging was significantly lower than that of SMB containing Ben and DC5700-Ben. In addition, FTIR showed that compared with Ben and DC5700-Ben, the Ben-fluid could inhibit the increase of carbonyl index and the decrease of butadiene index of SMB after aging. Comprehensive analysis suggested that Ben-fluid was more conducive to improve the physical, rheological and anti-aging properties of SMB.

A novel method to improve anti-aging properties of SBS modified bitumen by zinc oxide/expanded vermiculite composite: Influence of zinc oxide particle loadings

Styrene-butadiene-styrene copolymer modified bitumen (SBSMB) has been commonly used in pavement construction for its excellent performance. However, during construction and service life, SBSMB is inevitably subjected to thermal-oxidative or ultraviolet aging as a result of factors in the environment like heat, light and oxygen. This study investigated the effects of zinc oxide/expanded vermiculite composite (Z/E) on SBSMB, in particular the effects of Z/E with different zinc oxide (ZnO) particle loadings on SBSMB. And Z/E with different ZnO particle loadings were prepared and characterized by X-ray fluorescence spectrometer, field emission scanning electron microscope, UV–Visible spectrometer and Fourier transform infrared spectrometer tests. To age bitumen samples, thin film oven test, pressure aging vessel and ultraviolet aging tests were used. Eventually, the effects of Z/E with various ZnO particle loadings on the storage stability, physical, rheological and anti-aging properties of SBSMB were investigated. According to the results, Z/E with different ZnO particle loadings are successfully prepared. There are uniform ZnO particles on the surface of expanded vermiculite and ZnO particle loadings are increased with the concentration of the ZnO precursor solution. Furthermore, the high-temperature performance of SBSMB is enhanced, but the low-temperature performance is slightly affected by Z/E. Whatever the aging mode, the introduction of Z/E can obviously reduce the viscosity aging index, softening point increment, complex modulus aging index and increase phase angle aging index of SBSMB, demonstrating that the aging resistance of SBSMB are significantly enhanced. It was determined that SBSMB with 29.5 wt%Z/E had the best aging resistance.

Rheological properties of SBS-modified asphalt containing aluminum hydroxide and organic montmorillonite

The composite flame retardant composed of aluminum hydroxide (ATH) and organic montmorillonite (OMMT) is of potential application value in the tunnel asphalt pavement. To investigate the effect of ATH and OMMT on the rheological properties of SBS modified asphalt at high and low temperatures. In this study, the composite ATH/OMMT/SBS modified asphalt was subjected to multiple stress creep recovery (MSCR), linear amplitude sweep test (LAS), and Bending beam rheometer (BBR) experiments. Analysis of high and low temperature rheological properties and fatigue properties of composite ATH/OMMT/SBS modified asphalt under the conditions of single incorporation and composite modification. The findings of the tests suggest that ATH can significantly improve the fatigue life but has adverse impact on the creep recovery property of asphalt materials, OMMT has a significant improvement effect on the low-temperature performance, however, the detrimental effect of OMMT on fatigue performance is greater than the improvement of ATH. The research results provide a reference for the practical application of flame retardants.

Improving flame retardancy, fume suppression and mechanical properties of SBS modified binder using nano-porous fibers prepared by electrospinning

The current study utilizes polyacrylonitrile (PAN) as the foundational material, augmented with multi-walled carbon nanotubes (MWCNTs) and nano-calcium carbonate (nCC) as additives. Utilizing electrospinning techniques, micro-nanoscale composite fibers possessing elevated surface areas (MCE-PAN) were synthesized. Experimental data indicate that MCE-PAN enhances both the flame-retardant and mechanical attributes of the modified asphalt binder. Specifically, MCE-PAN elevates the limiting oxygen index (LOI) of the modified asphalt binder by 25.24%, increases smoke suppression efficiency by 10.67%, elevates the decomposition temperature by 105℃, and substantially curtails smoke emission. MCE-PAN manifests significant hydrophobic characteristics, thus augmenting the interfacial interactions between PAN fibers and the asphalt binder. Additionally, at an ambient temperature of 46℃, the complex modulus (G*) of the MCE-PAN/SBS/MA modified asphalt binder, with a 0.1% loading, surged by 52% relative to the SBS modified asphalt binder (SBS/MA); the storage modulus (G') escalated by 101.4%, and the loss modulus (G'') increased by 75.6%. Under low-temperature conditions, the MCE-PAN/SBS/MA modified asphalt binder demonstrates enhanced resistance to crack propagation. This investigation not only introduces an innovative approach to fiber synthesis but also elucidates its applicability in augmenting the performance and flame retardancy of asphalt pavements. It thereby holds significant practical, environmental, and energy-saving implications for sustainable, flame-retardant asphalt pavement, particularly in tunnel applications and high-temperature settings.

Study on Adhesion Performance and Aging Strength Degradation Mechanism of SBS Modified Asphalt with Different Anti-Aging Additive.

After aging, the adhesiveness of asphalt deteriorates, leading to a reduction in the durability of asphalt mixtures and affecting the service life of asphalt pavements. To enhance the anti-aging performance of asphalt, this study employed the method of melt blending to prepare three types of modified asphalt: graphene/SBS modified asphalt (G/SBSMA), crumb rubber/SBS modified asphalt (CR/SBSMA), and petroleum resin/SBS modified asphalt (PR/SBSMA). Different dosages of the three types of modified asphalt were tested for changes in conventional performance indicators. The optimal dosages of graphene, crumb rubber, and C9 petroleum resin were determined to be 2%, 15%, and 5%, respectively. Based on the theory of surface free energy, the effects of anti-aging agents on the microscopic properties of SBS modified asphalt before and after aging were analyzed using the three-liquid method. The mechanisms of strength attenuation at the asphalt-aggregate interface under water exposure and aging were revealed. The results showed that with the increase of aging gradient, the asphalt-aggregate biphasic system became more active. The cohesive energy and peel energy of SBS modified asphalt increased continuously, while the adhesive energy decreased continuously, leading to a decrease in the energy ratio parameter. Resin-based anti-aging agents exhibited the most significant improvement in asphalt adhesion performance, while graphene demonstrated a more stable enhancement in asphalt's water stability during the aging stage.

Effects of aging degradation and reactive reconstruction on the structure and properties of styrene–butadiene–styrene block copolymer

Achieving high-performance recycling of aged SBS modified asphalt will help promote the sustainable development of transportation infrastructure. The destruction of the SBS cross-linking network is an important reason for the deterioration of the performance of aged SBS modified asphalt. Scientific reconstruction of aged SBS cross-linked network is the key to achieving the performance recovery of aged modified asphalt. In this research, the evolution of chemical structure, molecular weight, thermodynamic properties, multiple stress creep recovery capability and rheological property of SBS during the process of aging degradation and reactive reconstruction were systematically investigated. The results showed that the molecular weight and creep recovery capability of SBS decreased sharply, and its complex modulus and phase angle exhibited a strong temperature and frequency dependence after aging. While the number average molecular weight of aged SBS increased by over 70% after reactive reconstruction, and its thermal-oxygen stability shown better performance as compared with that of fresh SBS. Meanwhile, the glass transition temperature of aged SBS was restored to −43.8℃ and −54.9℃ after reactive reconstructed by toluene diisocyanate (TDI) and isocyanate pre-polymer. Therefore, isocyanate pre-polymer with flexible long chain structure was more benefit for improving the low-temperature performance of reactive reconstructed aged SBS. Furthermore, the creep recovery ability and complex modulus of aged SBS were all significantly improved, and exhibited dramatically high-elastic properties after reactive reconstruction. And as compared with isocyanate pre-polymer, TDI with benzene ring rigid structure was more conducive to restoring the medium–high temperature rheological properties of aged SBS. Therefore, effective restoration of molecular weight and performance of aged SBS can be achieved by using reaction reconstruction method. This study would provide inspiration and ideas for the high-value recycling of waste polymer modified asphalt.

Carbon nanotubes for improving rheological and chemical properties of styrene–butadiene–styrene modified asphalt binder

ABSTRACT This paper studied the effects of CNTs on high-temperature rheological and chemical properties of SBS modified asphalt. Molecular dynamics simulation, DSR, BBR, and FTIR spectrometer were performed to evaluate the molecular motion state, rheological and chemical properties of CNTs and SBS composite modified asphalt binders at different aging states. The MD results indicated that CNTs could absorb components in SBS-modified asphalt and restrict the movement and diffusion of SBS and asphalt molecules, which enhanced the stability of SBS-modified asphalt. Meanwhile, the addition of CNTs could improve the rheological properties, temperature susceptibility, and rutting resistance of SBS-modified asphalt at high temperatures. The heterogeneity between CNTs and SBS-modified asphalt was demonstrated and it was the key to the high-temperature performance improvement. Besides, the low-temperature performance also could be improved by appropriate CNTs content. In addition, the FTIR results suggested that there was a lack of change in chemical functional groups with CNTs modification in asphalt binder. Moreover, the CNTs had a limited impact on delaying oxidation and played an active role in enhancing high-temperature performance under different aging conditions.

Rheological properties of composite DTDM/DOP/SBS modified asphalt and its effect on high and low temperature performance

To investigate the effect of crosslinker (DTDM) and plasticizer (DOP) on the rheological properties of SBS modified asphalt at high and low temperatures. In this study, the composite DTDM/DOP/SBS modified asphalt was subjected to infrared spectroscopy, dynamic shear rheology, and low-temperature bending beam rheology experiments. Analysis of microscopic properties and high and low temperature rheological properties of composite DTDM/DOP/SBS modified asphalt. The findings of the tests suggest that the cross-linking agent (DTDM) and plasticizer (DOP) have a better chemical response with SBS modified asphalt. It may significantly increase SBS modified asphalt's high-temperature deformation resistance, elastic recovery capacity, low-temperature fracture resistance, and aging resistance. The research findings have theoretical and practical significance for enhancing asphalt high and low temperature performance.

Analysis of rheological behavior and anti-aging properties of SBS modified asphalt incorporating UV absorbent and naphthenic oil (NPO)

This study aimed to comprehensively enhance the antiaging performance of SBS-modified asphalt (SBSMA) and make it available for long-life applications. UV absorbent (UV-531) and naphthenic oil (NPO) were selected to prepare composite modifiers to modify SBSMA, and then a series of aging tests were conducted. The rheological behavior and antiaging performance of the composite-modified asphalt binders were assessed by dynamic shear rheometer (DSR) and bending beam rheological (BBR) instruments. Then, Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) tests were conducted to investigate the influence of aging methods and the modifier on the functional groups and molecular weights of binders. The results indicated that the incorporation of the composite modifier weakened the rutting resistance, and markedly enhanced the cracking resistance of SBSMA. From the rheological point of view, adding the modifier could significantly improve the resistance of SBSMA to thermal-oxygen aging and UV aging under high and low temperatures. In addition, the UV-531/NPO was physically blended with SBSMA. The carbonyl index (CI) and sulfoxide index (SI) results indicated that the modifier can comprehensively improve the aging resistance of SBSMA, and the higher the content, the better the effect. Compared with control SBS, the 1.4# asphalt increased the small molecular size (SMS) by 1.44%∼2.73% and decreased the large molecular size (LMS) by 0.69%∼2.34%, proving that the composite modifier can provide more light components for SBSMA, especially in the case of a low aging degree.

A Study on High and Low Temperature Rheological Properties and Oil Corrosion Resistance of Epoxy Resin/SBS Composite Modified Bitumen

In order to investigate the high and low temperature rheological properties and fuel corrosion resistance of epoxy resin on SBS modified asphalt, epoxy resin/SBS composite modified asphalt (ER/SBS) was prepared by high-speed shear. Moreover, composite modified bitumen with different proportions were designed based on the uniform design method and the basic performance index test was performed. The optimal composite mixing ratio of the ER and SBS modifier in composite modified asphalt (2.3% and 3.8%, respectively) was determined. Temperature scanning and a multiple stress creep test (MSCR) on ER/SBS composite modified asphalt with different ER content before and after oil corrosion was carried out using a dynamic shear rheometer (DSR). In addition, the high temperature rheological properties of different ER contents and composite modified asphalt after oil corrosion were evaluated by combing DSR measurements with the test data. The creep stiffness (S) and creep rate (m) indexes were obtained by a bending rheometer (BBR), and the effect of ER on the low-temperature rheological properties of SBS modified bitumen was investigated. The influence of the modifier incorporation on the micromorphology of asphalt and the change of micromorphology of asphalt after oil corrosion were analyzed by fluorescence microscopy. The test results show that the incorporation of 2.3% ER and 3.8% SBS can effectively improve the high temperature performance of SBS modified asphalt under the premise of cost saving. Moreover, the composite modified asphalt doped with ER can effectively improve the resistance of SBS modified asphalt to fuel corrosion at high temperatures, and the greatest improvement in the oil corrosion resistance of composite modified asphalt is observed at the ER content of 2.3%.

Synergistic effect of waste rubber powder on low-temperature toughness and high-temperature rheological properties of SBS modified asphalt

The stacking and burning of waste tires have posed a serious challenge to the natural environment. To make adequate use of this misplaced waste resource, the study prepared waste rubber powder (WR) and SBS compound-modified asphalt (WSMA) by applying the appropriate process. Subsequently, the low-temperature and rheological properties of WSMA were studied according to the force-ductility tests, Brookfield viscosity tests, frequency sweep tests, and multiple stress creep recovery tests. The Refutas model, the modified Sigmoid model, and the five-parameter viscoelastic constitutive model were employed to quantitatively analyze the rheological properties of WSMA influenced by the temperature, loading frequency, loading time, and stress level. The results revealed that the low-temperature performance, high-temperature performance, temperature sensitivity, rutting resistance, creep recovery performance, and stress sensitivity of WSMA with high WR content outperformed. The addition of 20% WR reduced the viscoplastic damage deformation by 85.97%, and the residual viscoplastic damage deformation can also be decreased by 99.46%. Moreover, FTIR results showed that adding WR reduced the value of IAR, which was helpful in improving the elasticity recovery ability of WSMA. The study is important for environmental protection and the improvement of asphalt performance.

Structure-performance evolution on thermal-oxidative aging of CeO2/SBS co-modified asphalt

ABSTRACT Aging has a significant effect on the performance of asphalt, and the use of modifiers is the key to solving this problem. The mechanism of CeO2 effect on the thermal-oxidative aging resistance of SBS modified asphalt was explored by studying the microstructure and macroscopic properties of asphalt. The melt blending method was used to prepare CeO2/SBS co-modified asphalt, and the short-term thermal-oxidative aging process was demonstrated by a thin film oven test. Then, the effects of CeO2 on the properties of SBS modified asphalt were investigated by using dynamic shear rheometry, nuclear magnetic resonance, and electron paramagnetic resonance spectroscopy tests. The results showed that CeO2 increased the decomposition temperature of SBS modified asphalt and improved its thermal stability. The rheological results showed that the complex shear modulus aging index of CeO2/SBS co-modified asphalt is lower than that of SBS modified asphalt, and the phase angle aging index increases. In addition, CeO2 can make the internal molecular structure of asphalt produce more isomerisation and generate more long chains after aging. EPR results showed that CeO2 can reduce the generation of free radicals during aging, thus slowing down the generation of oxygen-containing functional groups and improving the thermal-oxidative aging resistance of asphalt.