Styrene-butadiene-styrene Content Research Articles

Effect of High Polymer, Crumb Rubber, and Epoxy-Modified Asphalt Binders on Laboratory Performance of Open-Graded Friction Course Mixtures

Open-graded friction course (OGFC) is a thin asphalt mixture surface layer. It is gap-graded with a high percentage of coarse aggregates that are nearly uniform in size, resulting in a high percentage of interconnected air voids and asphalt binder, which provides improved skid resistance, visibility, and decreased pavement–tire noise. However, construction personnel at the Louisiana Department of Transportation and Development reported that conventional OGFC mixtures have durability issues and shorter service life, compared with thin asphalt mixture lifts. Hence, effects of different asphalt binder types on the performance of OGFC mixtures were evaluated. Five types of asphalt binder were utilized: conventional styrene-butadiene-styrene (SBS) asphalt binder PG 76-22M; high SBS content asphalt binder PG 88-28; diluted epoxy asphalt (EA) binder with two different dosages (25% and 50%); and a hybrid modified asphalt binder prepared with SBS and crumb rubber modifier PG 76-22G. The optimal aggregate structures were determined based on minimum required air voids and voids in coarse aggregate. Physical and mechanical tests were conducted to assess the performance of OGFC mixtures, including draindown, permeability, loaded wheel track, and Cantabro abrasion loss. Results indicate that OGFC mixtures incorporating diluted EA binder exhibited lower draindown values than mixtures containing PG 76-22M and PG 88-28. Moreover, mixtures with PG 88-28 and 50% EA binders demonstrated improved resistance to rutting. Mixtures with 50% EA and PG 88-28 binders demonstrated improved durability, compared with mixtures with PG 76-22M for unaged and aged conditioning, as measured by Cantabro abrasion loss values.

Rheological behaviour of modified binders for different loading conditions and temperatures: A case of using pig tallow and crumb rubber from end–of–life tyres

This study investigates alternatives to Styrene-Butadiene-Styrene (SBS) polymer in asphalt mixtures by evaluating End-Of-Life tire (ELT) crumb rubber (CR) and fatty acid amide wax (FAA) derived from pig tallow. The research focuses on triple modification of binders with SBS, ELT and FAA to improve performance and reuse waste and industrial by-products in an economical and environmentally responsible manner. The results show that the incorporation of ELT and FAA significantly reduces the SBS content, achieving a 73 % improvement in elastic performance according to Multiple Stress Creep Recovery (MSCR) tests. In addition, this combination improves peak stress and fatigue life in Linear Amplitude Sweep (LAS) tests, demonstrating potential benefits in asphalt mixtures. The study concludes that the combination of pig tallow and end-of-life tire materials doubles the yield energy (Yield Energy of Asphalt Binders, BYET) compared to samples with higher SBS content. In particular, a modification with 6 % CR, 3 % SBS and 2 % FAA doubles the toughness (Er) of a binder with 5 % SBS. This contributes to higher tensile strength in asphalt mixtures, promoting sustainability and efficiency in the road construction industry. This study provides a deeper understanding of how the combination of ELT, FAA and SBS can optimize the properties of asphalt mixtures, highlighting the potential of these additives to improve performance, reduce costs and minimize environmental impact.

Improvement effect of different modifiers on storage stability of high content SBS modified asphalt

High content Styrene-butadiene-styrene (SBS) modified asphalt binder is commonly used for permeable pavements attribute to reasonable adhesion ability, deformation resistance and toughness. However, due to the large difference in molecular weight between styrene-butadiene-styrene block copolymer and asphalt, the compatibility between SBS and asphalt has always been a key issue restricting its development. To improve the compatibility of high content SBS modified asphalt, the preparation process of high content SBS modified asphalt (shear time, temperature, rate, modifier content) was investigated by orthogonal experimental design method. The effects of modifiers (polyphosphoric acid, montmorillonite, and sulfur) on the physical properties and compatibility of high content SBS modified asphalt were investigated by physical property tests, storage stability tests and dynamic shear rheology tests. The results shows that all three additives have improved the storage stability of high content SBS-modified asphalt, among which, nano montmorillonite has the best comprehensive improvement effect. In addition, the preparation process of high content SBS modified asphalt will also affect its physical properties and compatibility. When the content of MMT and SBS is 2% and 8% respectively, the shear temperature is 170 °C, the shear rate is 4000 rpm, and the shear time is 150 min, the high and low temperature performance of high content SBS modified asphalt is good and the compatibility is the best.

The Influence of Single-Walled Carbon Nanotubes on the Aging Performance of Polymer-Modified Binders.

The use of polymer-modified binders in asphalt concrete makes it possible to increase the efficiency and durability of highways. However, at present, there is an important and unresolved problem in this area, making it impossible to fully exploit the potential of modified binders. This is a tendency of aging processes that leads to the premature destruction of the pavement. In many literary sources, it is reported that reasons are related to the peculiarity of the chemical composition and occur at the submicron level. Therefore, the influence of single-walled carbon nanotubes has been studied for a better understanding of aging processes. The aging processes of the RTFOT (rolling thin film oven test) and PAV (pressure aging vessel) modified with SBS (styrene-butadiene-styrene) polymer, single-walled carbon nanotubes, and waste industrial oil were simulated in a laboratory furnace. Microstructural features were studied using the method of infrared spectral analysis. The dependences of viscoelastic properties on the component composition of binders were investigated. The optimal content of single-walled carbon nanotubes (0.001%), SBS (styrene-butadiene-styrene) polymer (3.5%), and waste industrial oil (4%) in the binder composition was established, which synergistically improved the performance of the modified binder from PG (52-22) (performance grade) to PG (64-34). It was established that single-walled carbon nanotubes provide improvement in the durability parameter ∆Tc binder by 150%, improved relaxation properties at low temperatures, and resistance to fatigue damage.

Analysis of SBS content quantitative determination and rheological properties of aged modified asphalt binder

The content of styrene–butadiene–styrene (SBS) modifier has a significant influence on the physical and chemical characteristics of asphalt. However, determining the SBS content in SBS modified asphalt (SBS MA) after aging remains a challenge. To facilitate the understanding of the relationship between physical properties and SBS content, the Fourier transform infrared (FTIR) and potentiometric titration test were utilized to detect SBS content of aged binders. In this paper, radial and linear SBS were incorporated into asphalt binders at three levels, and their rheological properties were investigated after thin film oven aging (TFOT) and long-term aging. Furthermore, the actual SBS content versus the rheological index at different aging stages was investigated. The results showed that both IC=C and Na2S2O3 titration volume highly correlated with SBS content (R2 > 0.99), and there was only a slight difference between the actual content of SBS determined by the two methods. The fatigue resistance, high-temperature elastic, and low-temperature cracking characteristics of asphalt were weakened after aging, due to SBS degradation, especially in the early stage. In addition, the resistance to deformation, elastic recovery, anti-fatigue properties of radial SBS MA were superior to that of linear SBS MA at the same SBS content, while the low-temperature cracking performance demonstrated an opposite trend. The actual SBS content versus the rheological indexes after aging can be well-fitted by a nonlinear equation. Therefore, FTIR and potentiometric titration tests can effectively predict SBS content and analyze the aging degree of SBS MA.

Preparation and performance analysis of high-viscosity asphalt containing high-content SBS and crumb rubber by oxygen-free high-temperature treatment

Styrene-butadiene-styrene (SBS) and crumbed rubber (CR) are widely used for asphalt binder modification in the field of road materials. Especially, the high-viscosity asphalt with high-content SBS/CR modifiers has been applied for constructing the porous pavement and ultra-thin overlay. However, the workability of the SBS/CR modified asphalt still needs to be improved due to many unswollen polymer particles in the blended system. This work aims to propose an oxygen-free high-temperature treatment method to reduce the viscosity of SBS/CR-modified asphalt at construction temperature for better workability. Viscosities at 60 °C and 180 °C were tested to obtain the content of SBS, CR, and tackifying resin for high-viscosity asphalt; multiple physical tests were conducted to obtain acceptable heating temperature, initial pressure, and reacting time; the two high-viscosity asphalt binders cured under various conditions were compared through physics, chemistry, and rheology properties. The results show that the 70# asphalt incorporating 10% SBS, 6% CR, and 9% (by weight of asphalt binder) resin can prepare ideal high-viscosity asphalt binders. After high-speed shearing, it was recommended that CR-SBS-asphalt blends be cured in the reactor at the initial pressure of 3 MPa and temperature of 200 °C for 45 mins. The improved reaction conditions increased light components in a homogeneous and formed a stable modified asphalt blended system. Hence, the low-temperature performance and workability were improved, despite weakening the rutting resistance, which was still excellent at the high temperature.

Effects of using waste solid sheet photopolymer plates in combination with SBS on the rheological properties of bitumen

ABSTRACT Large quantities of Solid Sheet Photopolymer plates (SSP) are used and wasted by the flexographic printing industry worldwide. The use of waste SSP, contains valuable polymers for bitumen modification, is an effective way of disposing of post-consumer products and an alternative way of obtaining new modifiers with good properties. Styrene–butadiene-styrene (SBS) copolymer, which is widely used in bitumen modification, causes excessive costs. The purpose of this study is to look at the effects of using SSP in combination with SBS and how much SSP saves on SBS content. Dynamic Shear Rheometer (DSR), Multi-Stress Creep Recovery (MSCR), Bending Beam Rheometer (BBR), Storage Stability tests, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) were carried out. The performance of the 4 and 5 wt.% single SBS modifications was compared with the SBS + SSP combination. SBS and SSP additives were found to interact well, and the use of 7% SSP in combination with 2% SBS provided improved low and high temperature performance and storage stability compared to the single 5% SBS modification. The use of waste SSP, which is cheaper than bitumen, together with SBS in bitumen modification offers a cost-effective and environmentally friendly solution without compromising performance.

Influence of SBS on the Aging Properties of High-Content Terminal Blend Rubber Modified Asphalt

The goal of this study was to investigate the effect of styrene-butadiene-styrene (SBS) polymer on the aging properties of high-content terminal blend rubber modified asphalt (HCTBMA). All asphalt was tested for chemo-rheological properties using an attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) test, temperature sweep test, frequency sweep tests, and multiple stress creep recovery (MSCR) test. According to ATR-FTIR observations, SBS can retard the oxidation effect of HCTBMA during short-term aging, but its inhibitory effect is reduced during long-term aging. Furthermore, aging aggravates the degree of desulfurization of crumb rubber in HCTBMA as the SBS content increases. Compared with HCTBMA, neat asphalt has a lower elasticity at high temperatures and a higher elasticity at low temperatures. The addition of SBS to HCTBMA improves the elasticity of the material. The elasticity of HCTBMA decreases and then increases after aging, and SBS can reduce the aging degree of HCTBMA after aging. Moreover, based on Pearson correlation analysis, the correlation between the desulfurization of rubber and the degradation of polybutadiene in HCTBMA during aging is high.

Improvement of Engineering Properties of Asphalt Binder and Mixture by Using SBS Additive Material

Rutting, thermal cracking, and stripping are among the most severe distress types in asphalt pavement. In this study, a specified type of styrene-butadiene-styrene (SBS) was used as a modifier for a low viscosity asphalt binder G80/100 (PG 58-22) to overcome the issues of the distresses in the asphalt mixture. The mixing process had been evaluated by using fluorescent microscopy. The control- and SBS-modified binders were subjected to all conventional and Superpave binder tests. The Hamburg wheel tracker (HWT) and indirect tensile strength ratio (ITSR) tests were conducted to evaluate the engineering properties of the control and modified asphalt mixtures. The used SBS percentages were 1, 2, 3, 4, and 5% of the total weight of the binder. The results showed lower penetration, higher softening point, viscosity, and elastic recovery. The dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests showed an increasing SBS% leading to an increase in both values of high and low temperatures of the asphalt performance grade (PG). The tensile strength ratio and Hamburg wheel tracker tests’ results showed that the highest TSR and rutting parameter values were obtained at 3% SBS, which was the optimum SBS content for the asphalt mixture and the resulted modified asphalt is PG76-16.

Engineering properties of SBS and crumb-rubber modified bitumen – a design of experiment approach

Purpose Cracking, deformation and rutting are the most prevalent types of pavement distress, and these deformations and flow characteristics greatly distress the pavement features while also limiting its use. In India, on the other hand, more than 300 million scrap tyres are generated each year, and their disposal has become a severe environmental issue. Furthermore, the scrap generated by the used tyre must be disposed of properly. Hence, this study presents the experimental investigations of bitumen incorporating with Crumb rubber as main additive along with SBS polymer, to enhance the engineering property. Design/methodology/approach Crumb rubber (CR) was used as an additive along with styrene–butadiene–styrene (SBS) polymer to enrich the engineering qualities of the bitumen to reduce the disposal problem of scrap tyres and reduce the risk of environmental pollution. Because SBS polymer is expensive, response surface methodology modelling's central composite design (CCD) was used to optimise the number of tests. CCD modelling's input factors (process variables) were the inclusion rates of SBS and CR, which ranged from 2% to 5% and 4% to 10%, respectively, by total weight. Furthermore, the influence of SBS polymer and CR on the characteristics of modified bitumen was prioritised. Findings The addition of SBS and CR enhanced the bitumen's penetration resistance at service temperatures. Furthermore, increasing the SBS and CR concentration affected the flow characteristics of the modified bitumen and enhanced its viscosity. The addition of SBS and CR as bitumen modifiers increased penetration resistance by 24.06%. The Dynamic Shear Rheometer test demonstrated that the complex modulus of virgin bitumen increases with increasing SBS and CR content, which is consistent with the shifting softening point trend. The dosing rate of up to 3.5% SBS and 11% CR considerably contributed to the creation of polymer link networks, which increased the complex modulus of the bitumen by 16.5%. The CCD model's analysis of variance and Pareto bar chart demonstrated that the dose of CR is significant in improving the engineering features of the virgin bitumen rather than the SBS. Originality/value The utilisation of CR as a bitumen modifier may solve the problem of waste tyre disposal while also lowering the risk of environmental damage. Furthermore, because the presence of CR increased the engineering properties, particularly the complex modulus of virgin bitumen, the use of CR in combination with SBS polymer can be an efficient and cost-effective strategy to improving bitumen qualities.

Factors Influencing the Low-Temperature Properties of Styrene-Butadiene-Styrene Modified Asphalt Based on Orthogonal Tests.

Styrene-butadiene-styrene (SBS) is widely used in asphalt modification to obtain superior high-temperature performance. Nevertheless, studies on the low-temperature properties of SBS-modified asphalt are not satisfactory. Orthogonal tests are valid in analysing the results. In this paper, the main factors (SBS content, sulfur content, and the addition of rubber processing oil) for improving the low-temperature performance of SBS-modified asphalt were analyzed base on the orthogonal tests. Firstly, the frequency sweep test, bending beam rheometer (BBR) test, and force-ductility test were conducted to evaluate the low-temperature properties of SBS-modified asphalt. Investigation of low-temperature parameters obtained through these tests was conducted base on the orthogonal analysis method. The G-R parameter was abandoned in the analysis of the orthogonal method for the result that the increase of SBS content was negative to the low-temperature properties by the Glover-Rowe (G-R) parameter, which were contrary to the results of BBR and force-ductility tests. Moreover, the other parameters (ΔTc and toughness) sorted according to the orthogonal analysis method indicated the effect on low-temperature performance of the SBS-modified asphalt as SBS content > rubber processing oil > sulfur. As shown above that both SBS and rubber processing oil play a critical role in improving the low-temperature properties of SBS-modified asphalt, for SBS could resist the generation and subsequent propagation of cracks while the rubber processing oil could supplement the maltene loss.

Artificial Neural Network (ANN) Modeling for Predicting Performance of SBS Modified Asphalt.

Due to the superiorities of Styrene butadiene styrene (SBS) modified asphalt, it is widely used in civil engineering application. Meanwhile, accurately predicting and obtaining performance parameters of SBS modified asphalt in unison is difficult. At present, it is essential to discover an accurate and simple method between the input and output data. ANNs are used to model the performance and behavior of materials in place of conventional physical tests because of their adaptability and learning. The objective of this study discussed the application of ANNs in determining performance of SBS modified asphalt, based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) tests. A total of 150 asphalt mixtures were prepared from three matrix asphalt, two SBS modifiers and five modifier dosages. With the most suitable algorithm and number of neurons, an ANN model with seven hidden neurons was used to predict SBS content, needle penetration and softening point by using infrared spectral data of different modified asphalts as input. The results indicated that ANN-based models are valid for predicting the performance of SBS modified asphalt. The coefficient of determination (R2) of SBS content, softening point and penetration prediction models with the same grade of asphalt exceeded 99%, 98% and 96%, respectively. It can be concluded that ANNs can provide well-satisfied regression models between the SBS content and infrared spectrum statistics sets, and the precision of penetration and softening point model founded by the same grade of asphalt is high enough to can meet the forecast demand.

Study on Adhesion Property and Moisture Effect between SBS Modified Asphalt Binder and Aggregate Using Molecular Dynamics Simulation.

In this project, the adhesion property and moisture effect between styrene–butadiene–styrene (SBS) modified asphalt binder and aggregate were studied to reveal their interface adhesion mechanism. The influence of SBS contents on adhesion property and moisture effect between binder and aggregate phases were investigated using molecular dynamics simulation. Moreover, the double-layer adhesion models of asphalt binder–aggregate and triple-layer debonding models of asphalt binder–water–aggregate were constructed and equilibrated, and the adhesion property and the moisture effect were evaluated numerically. The results indicate that the built SBS-modified asphalt binder models show favorable reliability in representing the real one. The variation in the work of adhesion for SBS modified asphalt binder–quartz is not remarkable with the SBS content when its content is relatively low. However, the work of adhesion decreased significantly when the content was higher than 6 wt.%, which is consistent with the experimental results. The adhesion between SBS-modified asphalt binder and quartz is derived from Van der Waals energy. The modified asphalt binder with a high SBS modifier content (8 wt.% and 10 wt.%) shows much better moisture resistance (nearly 30% improved) than the unmodified asphalt binder from the work of debonding results. According to the Energy Ratio (ER) values, asphalt binders with high SBS content (8 wt.% and 10 wt.%) present a good moisture resistance performance. Therefore, the SBS content should be seriously selected by considering the dry and wet conditions that are used to balance the adhesion property and debonding properties. The content of 4 wt.% may be the optimal content under the dry adhesion and moisture resistance.

Quantifying the effect of SBS molecular structure on the upper service temperature rheological properties of modified binders

At upper service temperatures, rutting is one of the common ways through which asphalt pavements fail. The use of polymer modified binders (PMBs) significantly reduces the rutting tendency in asphalt pavements. Commercially, styrene–butadienestyrene (SBS) polymers with different molecular structures are used extensively for asphalt binder modification. Modified asphalt binders were prepared using four commercial-grade SBS polymers having different molecular structures (Linear, radial, high vinyl, and diblock) and at SBS content of 3, 4.5, and 7 wt%. Frequency sweep measurements (0.01–100 rad/s) were performed on the modified asphalt binders at 60 °C. Frequency sweep analysis reveals that the influence of molecular structure on the upper service temperature rheological properties is predominantly observed at lower frequencies (≤0.1 rad/s). At 0.01 rad/s frequency, the divergence in complex modulus and phase angle among the SBS modified binders with the four SBS polymers with different structures were ≈ 500 % and ≈ 25°, respectively. While at 10 rad/s, the variation in complex modulus and phase angle was only 60 % and 5°, respectively. The higher molecular weight (Mw), triblock structure, rigid polystyrene segments at the chain ends, and long radial branches in radial SBS polymer results in a stronger polymer network in the binder. The lower Mw and diblock structure in diblock SB polymer resulted in a weaker polymer network in the binder. The result implies that the rheological signature of the SBS polymer and its structure was predominantly observed at lower frequencies (<0.1 rad/s). Irrespective of the four SBS polymers, the correlation (R2) of the rheological properties with rutting was enhanced significantly at frequency ≤ 0.1 rad/s. This study illustrates the importance of lower frequencies in quantifying the effects of the SBS structure on the upper service temperature rheological properties of SBS-MABs. For a good correlation, effective grading, and quality control, the rheological variable at frequency ω ≤ 0.1 rad/s is important in modified asphalt binders.

Investigation on mechanism and rheological properties of Bio-asphalt/PPA/SBS modified asphalt

To promote the application of environmentally-friendly and sustainable bio-asphalt (BA) in road engineering, polyphosphoric acid (PPA) and styrene–butadienestyrene (SBS) were used to prepare BA/PPA/SBS composite modified asphalt. The mechanical properties of composite modified asphalt and the interaction mechanism of each modifier were investigated through conventional property, rheological property, infrared spectroscopy, fluorescence microscopy test, and gravimetry analysis for SARAs fractions. The conventional property test results show that PPA and BA improve the storage stability of SBS modified asphalt, and the composite modified asphalt with lower SBS content still has excellent performance. The rheological property test results show that the decrease of SBS content has negative effect on the rheological property of asphalt. But in general, the composite modified asphalt has good high-temperature deformation resistance. The IR-spectra of BA before and after reacting with PPA indicates that the chemical composition of the BA in this study was mainly sugar alcohols, and the esterification reaction occurred during reaction with PPA. By comparing the fluorescence images, it was found that the BA significantly improve the dispersion and compatibility of SBS particles in asphalt. The SARAs fractions analysis shows that the composite modified asphalts have higher content of asphaltenes and aromatics.

Investigation of the High-Temperature and Rheological Properties for Asphalt Sealant Modified by SBS and Rubber Crumb.

Crack sealing is an important measure for pavement maintenance. Hot-poured crack sealant is the most utilized material for crack sealing. However, its poor high-temperature and rheological properties seriously weaken the mechanical properties of repaired pavement. Thus, to overcome the disadvantage of the poor high-temperature and rheological properties of sealant, styrene–butadiene–styrene (SBS) and rubber crumb (CR) were utilized for modifying the asphalt-based sealants. Softening point tests, temperature tests, frequency scan tests, and multiple stress creep recovery tests (MSCR) were conducted to evaluate the high-temperature and rheological properties of the modified sealant. Additionally, the influence of SBS and CR on the high-temperature performance of the modified sealant was quantitatively analyzed by the grey relational analysis method. The results reveal that the SBS has a greater enhancement effect on the high-temperature performance of sealant than CR. Increasing the SBS and CR content in the sealant could enhance the sealant’s high-temperature performance, stiffness, and elasticity. Compared with asphalt-based sealant and one-component modified asphalt-based sealant, SBS/CR-modified asphalt sealant has greater viscosity and higher temperature deformation resistance. Additionally, SBS can increase the stress level of the sealant, thereby enhancing the resistance of the sealant to permanent deformation.

Quantitative detection of polymer content in styrene‐butadiene‐styrene modified asphalt after aging

AbstractThe identification of styrene‐butadiene‐styrene (SBS) content is crucial in engineering applications since the key to assessing the performance of aged‐modified asphalt is the SBS content. Six types of modified asphalts with various SBS contents were prepared, and physical, rheological, and Fourier‐transform infrared spectroscopy (FTIR) tests were conducted. The fitting relationship between aged‐modified asphalt indexes and SBS content was established, and the three methods' accuracy, simplicity, and efficiency were compared and analyzed. The results showed that the fitting relationship between SBS content and viscosity could exceed 0.83 after aging. However, the linear and quadratic fittings deviated from the measured values, and the softening point had no apparent law with the SBS content. The rheological index method significantly correlated with SBS content and is highly automated. However, FTIR was established based on the direct detection of SBS characteristic peaks compared with the physical and rheological indexes methods. It could directly reflect the SBS content and was not easily disturbed by SBS substitutes. In addition, after long‐term aging, the linear relationship between SBS characteristic peak index, A966/A811, and SBS content could exceed 0.97. The FTIR test exhibited high accuracy and fast detection speed and is the best detection method for SBS content.

Laboratory Study on CR/SBS Modified Asphalt: Preparation and Performance Characterization

Crumble rubber (CR) can be used to prepare CR and styrene-butadiene-styrene (SBS) composite modified asphalt with a good high-and low-temperature performance, meanwhile the addition of CR could work as the substitute for SBS and help reduce the content of SBS. This study contains three main parts: effect of preparation and effect of material composition as well as rheological performance characterization. Factors during the preparation, including shearing temperature, shearing time, mixing time and swelling time, were selected, while base binder, CR content, CR particle size and SBS content in material composition were considered. The effects of these factors were assessed in terms of the conventional performance (penetration, softening point, ductility and storage stability). After identifying these effects, the sample of CR and SBS modified asphalt at the selected preparing condition and material composition (CR/SBSMA) was made, and the corresponding SBS modified and CR modified asphalt (SBSMA and CRMA) were produced for the comparing reason. Subsequently, temperature sweeps from 0°C to 80°C were utilized to depict the viscoelasticity of these modified asphalt binders by complex modulus and phase angle. Multiple stress creep recovery tests (MSCR) at 64°C and bending beam rheometer tests (BBR) at various low temperatures were employed to evaluate the high-and low-temperature performance, respectively. Results highlight that that CR/SBSMA could exhibit an excellent high-temperature performance (better than SBSMA), and a good low-temperature performance (reaching the level of base binder).

Study on Properties of Drainage SBS Modified Asphalt Mixture with Fiber

In order to improve the road performance of drainage SBS modified asphalt mixture, basalt fiber was added to prepare drainage styrene-butadiene-styrene (SBS) modified asphalt mixture. The viscosity-toughness, toughness, and 60°C dynamic viscosity of SBS modified asphalt were tested. The modification effect was evaluated from the perspective of high and low temperature rheological properties by dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The high temperature stability, water stability, low temperature crack resistance, and drainage of basalt fiber SBS drainage asphalt mixture were evaluated and compared with nonfiber SBS drainage asphalt mixture and TPS drainage asphalt mixture. The morphology characteristics of asphalt mixture and the distribution of basalt fiber in the mixture were analyzed from a micro perspective. The results showed the following: the overall performance of basalt fiber is better than that of lignin fiber. SBS modifier content in 7% can meet the requirements of drainage asphalt pavement on asphalt binder. The optimum asphalt content of SBS modified asphalt mixture with basalt fiber content of 0, 0.15, 0.25, and 0.35% is 4.9, 5.05, 5.15, and 5.2%. The fiber is irregularly distributed in the mixture to form a three-dimensional network structure, which has a series skeleton function. It plays a tensile role in the initial cracking of asphalt mixture and prevents further expansion of cracks.

A Rapid Method for the Determination of SBS Content Based on the Principle of Orthogonal Testing

The performance of Styrene-butadiene-styrene (SBS) modified asphalt is closely related to the content of SBS modifier. In the production process of modified asphalt, a certain amount of additive such as sulfur and rubber oil may be added to reduce the segregation and promote the swelling of the polymer, but the effect of these additives on determining SBS content in asphalt is not yet clear. This paper presents the calibration curves of SBS content based on rutting factor and creep slope and points out its defects according to the temperature scanning test and the bending beam rheometer test. Subsequently, using Fourier transform infrared spectroscopy (FTIR) for rapid determination of polymer content in SBS modified asphalt based on orthogonal test and then the effects of additives such as asphalt type, SBS content, rubber oil and sulfur on the accuracy of polymer content determination by FTIR were investigated. Moreover, in the orthogonal tests of adding sulfur and rubber oil, the multivariate analysis of variance (MANOVA) was firstly used to analyze the additives influence on the test accuracy of FITR. Results indicated that the influencing degree of different additives is different. The influence of sulfur on the determination accuracy is greater than that of rubber oil. Therefore, the rapid determination method needs further improvement.