Bituminous Mixtures Research Articles

Road Performance and Self-Healing Property of Bituminous Mixture Containing Urea-Formaldehyde Microcapsules.

Urea-formaldehyde (UF) is a common shell material for self-healing microcapsules; however, the influence of urea-formaldehyde microcapsules (UFMs) on the road performance of bituminous mixtures and the sensitivity of their healing abilities remains unclear. In this paper, UFMs were prepared via in situ polymerization (ISP), followed by an investigation into the road performance of UFM self-healing bituminous mixtures through various tests, including wheel tracking, immersed Marshall, freeze-thaw splitting, low-temperature bending, and three-point bending fatigue tests. Subsequently, the impact of the damage degree, healing duration, and temperature on the self-healing property was discussed. The results indicated that incorporating 3 wt% UFMs into bitumen significantly improved the high-temperature stability and fatigue resistance of the bituminous mixture; for example, its dynamic stability and fatigue life could be increased by about 16.5% and 10%, respectively. However, it diminished the thermal crack resistance, as evidenced by decreases in bending tensile strength and strain by 3.7% and 10.1%, respectively. And it did not markedly improve the moisture susceptibility. Additionally, the maximum improvement observed in the healing rate was about 9%. Furthermore, the healing duration and temperature positively influenced the bituminous mixture's self-healing, whereas the degree of damage exerted a negative impact, with a relatively significant effect.

Valorisation of Pulp and Paper Industry Wastes—Incorporation in Bituminous Mixtures for Road Construction

Some wastes from the paper pulp production process are still sent to a controlled waste landfill. These materials can constitute alternative resources for constructing road pavements. The study aimed to characterize and explore the sustainable application of two inorganic wastes resulting from the paper pulp process, the dregs (green liquor wastes) and the grits (slaker wastes), in the production of bituminous mixtures by the analysis of samples prepared with 5 and 10% of dregs and 5 and 10% of grits on the baseline reference bituminous mixture AC 14 surf 35/50. Some relevant mechanical properties of the blends were assessed based on Marshall compression, sensitivity to water and wheel-tracking tests. Additionally, water poured on the loose asphalt and compacted slabs’ surface was analysed to determine the portion of harmful chemical compounds leached from the asphalt material. The results show that using dregs presented some technical limitations related to mechanical performance and that the incorporation of grits has an acceptable mechanical behaviour. Moreover, the study shows that the measured leachate resulting from water flow in a reference asphalt mixture and the blends with grits are insignificant. It can be concluded that using grits in asphalt mixtures is a promising technique regarding mechanical behaviour and environmental impacts that need further studies.

Influence of Filler Materials on Bituminous Mastic Rheology at High Temperatures

The mixing and compaction temperatures of the bituminous mixture are determined by the viscosity of the binder. It was always a concern to understand the influence of the type of filler on the workability of the bituminous mixture. The interaction of the filler with the bitumen plays a key role in this. The inert filler has a physical interaction with the binder, and the active filler will have both a physical and chemical interaction. Based on the type of interaction, the viscosity and shear thinning characteristics of the mastic (binder + filler) change, which will hence influence the workability of the bituminous mixture. An experimental investigation is conducted to measure the viscosity of the mastic with two types of filler, one chosen from the active filler category (hydrated lime) and another from the inert filler category (quarry dust). A shear rate sweep experiment was carried out within the temperature range of 100 to 160 °C to analyze the Newtonian and shear thinning responses of the mastic. Results indicate that, for an equivalent weight proportion of the filler, mastic containing quarry dust exhibited elevated Newtonian viscosity and zero-shear viscosity (as predicted using the Carreau Yasuda Model). Additionally, quarry dust mastic demonstrated a higher rate of shear thinning. Consequently, the beneficial effect of shear thinning during the compaction of bituminous mixtures has the potential to enhance workability and streamline the compaction process. Doi: 10.28991/CEJ-2024-010-02-013 Full Text: PDF

Potential Use of Reclaimed Asphalt Pavement Aggregate and Waste Plastic Bottles for Sustainable Asphalt Pavement Production

The main objective of this study was to evaluate the potential use of reclaimed asphalt pavement aggregate (RAPA) and waste plastic bottles (WPBs) for sustainable asphalt pavements production in hot weather conditions. To enhance the adhesion between neat bitumen, RAPA, and WPBs-coated aggregates, a rougher surface texture is created for aggregate particles in the modified asphalt mix. This improvement enhances asphalt mix engineering properties, rutting resistance, and stability. However, bituminous mixtures containing 20% RAPA exhibit tendencies toward strip resistance, this mixture is weak in terms of strength and incapable of supporting loads when utilizing the RAPA. Therefore, due to the moisture susceptibility of the RAPA, it is advised to employ several types of aggregates in future studies to determine the optimal aggregate that can resist stripping and, at the same time, handle heavy loads. Finally, for better asphalt mix performance, it is recommended to use a combination of 70% crushed stone aggregate, 20% RAPA, and 10% WPBs in asphalt mix with a 5.0% optimum modifier content. The experimental results for tensile strength ratio, proportional rut depth, and mean rut depth meet the required specifications of the Ethiopian Road Authority for all properties tested. Therefore, this combination is strongly advised for use in hot mix asphalt production.

Performance investigation of phenol–formaldehyde resin (PF) and organic montmorillonite (OMMT) compound-modified bituminous mixture

ABSTRACT Composite modification has proven to be an effective strategy in addressing the insufficient performance associated with single-modified bituminous mixture. This research aims to thoroughly investigate the performance of the compound-modified bituminous mixture incorporation phenol–formaldehyde resin (PF) and organic montmorillonite (OMMT). The performance investigations of the bituminous mixture were conducted through the Marshall stability test, dynamic stability test, indirect tensile test, immersion Marshall test, freeze–thaw splitting test, indirect tensile fatigue test and long-term aging test. The test results indicated that OMMT plays a crucial role in advancing thermal storage stability and compatibility between PF and bitumen. Importantly, the optimal dosage of OMMT was determined not to exceed 5%. The 3%PF+5%OMMT bituminous mixture demonstrated excellent rutting and cracking resistance, superior water stability and anti-fatigue capabilities. Furthermore, the 2%PF+5%OMMT and 3%PF+5%OMMT bituminous mixtures exhibited superior anti-aging abilities. In consideration of laboratory performance and bitumen compatibility, the combination of 3%PF+5%OMMT can be utilised to enhance the bituminous mixture performance. The results of single-factor analysis of variance indicated that PF and OMMT had significantly impact on the bituminous mixture performance. Notably, the influence of PF/OMMT dosage on the cracking resistance, water stability and anti-aging ability requiring attention when considering them as bitumen modifiers.

Management of Road Paving Processes – Application Case

Infrastructure construction companies encounter numerous challenges in managing large and dispersed teams, along with fragmented or non-existent operational data. These challenges often result in delays, inefficiencies, and over-budget projects. Road pavement works are an example of this, as they heavily rely on expensive heavy construction equipment that requires detailed planning and real-time adjustments. Also, pavement quality is closely linked to the quality of the asphalt mixture in terms of viscosity and compactability, which is significantly influenced by temperature. This paper describes the features, challenges and results of a road paving real-time management system that was conceived in a co-creation environment with a construction company. Such a partnership has allowed to specify the requirements of such an application aligned with the identified needs of a real-world development. According with the state-of-the-art, this innovative system is unique in the way it is manufacturer-agnostic and designed to be compatible with most situations. It is also data production-oriented to allow future developments that may provide business analytics or scientific research in the road paving area. This work also presents the development of sensors such as a high precision geolocalized infrared matricial temperature sensor for the application of the bituminous mixture, the data and communication structure, and a web-based interface that manages the construction projects for different stakeholders.

Effects of crumb rubber and styrene-butadiene rubber additives on the properties of asphalt binder and the Marshall performance properties of asphalt mixtures

The primary aim of this study is to evaluate the impact of incorporating crumb rubber (CR) and styrene-butadiene rubber (SBR) additives, ranging from 0% to 5% by weight of bitumen, on the performance of a bituminous concrete mixture using the wet process. Laboratory experiments, including the Marshall test, were conducted to establish the optimum bitumen content (OBC) for the hot mix. The study focuses on determining the optimal proportions of CR and SBR to achieve maximum strength. The results show that increasing the proportions of both CR and SBR leads to significant improvements in strength, with the maximum stability recorded at 16.14 kN and a flow of 1.23 mm for a mix containing 5% CR and 4% SBR. The findings further suggest an inverse relationship between CR content and strength, while an increasing SBR content enhances strength. Consequently, the optimal proportions for incorporating CR and SBR additives are identified as 5% and 4%, respectively.

Reinforcement corrosion in self-compacting concrete made with waste filler of bituminous mixtures

This study aims to investigate the properties of self-compacting concrete (SCC) manufactured with a recovered filler (RF) that comes from hot-mix asphalt plants. This material is a waste that sometimes implies an environmental problem and its use in the manufacturing of concrete could be solved it and would be a new sustainable way of casting concrete. The use of this material did not compromise the self-compacting character of the concrete. Durability properties are barely studied when a new product is incorporated to a construction material. This work estimates the service life related to reinforcement corrosion of a SCC elaborated with the waste from hot-mix asphalt plants. Mechanical properties were studied, especially those related to its behaviour against rebar corrosion, and according to the results, this SCC might allow structure durability similar to those elaborated with conventional raw materials. In other words, acceptable service life will be achieve based on carbonation as well as chloride penetration. Furthermore, good behaviour against shulphates has been demonstrated.

Determining the fracture stiffness of modified Hot and Warm Mix Asphalt using semi-circular bending (SCB) geometry

Determining the bituminous mixture’s resistance against elastic deformations is a critical parameter for designers. The presented standards have reviewed this index for semi-circular bending (SCB) geometry comprising 90-degree cracks; however, determining this index for SCB geometry containing inclined cracks can help the understanding of researchers in this field. By doing so, a total of five Hot Mix Asphalt (HMA) and five Warm Mix Asphalt (WMA) comprising different ratios of polyester fibers (PEF) and calcium lignosulfonate powder (CLSP) were constructed and tested. The results indicated that the HMA mixture containing 0.25 % PEF + 6 % CLSP had the best performance in terms of two indicators pre-peak fracture energy (GPf) as well as after-peak fracture energy (GAf) at temperatures of −18 °C and +25 °C and under modes I and II. Moreover, the WMA mixture containing 6 % calcium lignosulfonate was selected as the best mixture concerning these two indicators. Under Mode II and for the modified HMA mixture with both additives, an increase of 74 and 49 % GPf and 70 and 69 % GPf was obtained at temperatures of −18 and +25 °C, respectively. Also, an increase of 144 and 78 % GPf (23 and 11 % GAf) and 145 and 46 % GPf (93 and 26 % GAf) were obtained under mode I at temperatures of −18 and +25 °C, respectively. On the other hand, under mode II and for the WMA mixture modified with 6 % CLSP, an increase of 24 % GAf at −18 °C and a 14 % increase of GAf at +25 °C was obtained. Under mode I, an increase of 60 % GPf and 84 % GAf and an increase of 1 % GPf and 24 % GAf was achieved at −18 °C and +25 °C. Regarding TSI and TS indicators, the finding demonstrated that the HMA mixture comprising various ratios of additives had a lower resistance to elastic deformation than the additives-modified WMA mixes at −18 °C (under modes I and II); however, mixes reinforced with additives had a higher mechanical response in absorbing the load introduced in the elastic region (+25 °C). The finding demonstrated that the stiffness of a bituminous mixture comprising inclined cracks can be determined by SCB geometry.

Pavement design using bituminous surface course with recycled aggregates

The utilization of Recycled Aggregates (RA) in the construction of pavement structure is one of the inventive and eco-friendly construction techniques. This scale down the construction cost without negotiates the strength and the durability of the pavement structures. However, RA is rigid in nature because it is obtained from aged bituminous mixtures to enhance a rejuvenator is usually added in order to lower the stiffness. Rejuvenator surges the utility of the bituminous mixtures and makes them be smoothly paved and compacted. The objective of this study is to design a flexible pavement structure using Stone Matrix Asphalt (SMA) as a surface course in order with RA. In SMA mixture major component is occupied by coarse aggregates, mineral filler, bitumen and a minor component of fine aggregates helps to fill the voids present in coarse aggregate which gives stone-on-stone contact. The bitumen binder and mineral filler form mastic, providing durability to the mixture. In this study, the performance of SMA mixtures with different RA proportions and a rejuvenator will be compared with conventional SMA mixture with zero percentage RA. Marshall Mix design is outlined to find the Marshall and volumetric properties of SMA mixtures and to regulate the Optimum Binder Content (OBC). The mixtures will be compared based on the drain down, stripping, Indirect Tensile strength (ITS) and Semi circular bend (SCB) test results. The analysis and design of flexible pavement structure using the prepared SMA mixtures with different RA contents as surface courses also will be carried out as a component of the study.SMA mixture of 40% replacing RA with 3% of palm sludge oil as rejuvenator exhibits optimum bitumen content where vertical stress, strain and displacement obtain reduction with compared to IRC 37 conventional SMA mixture.

The possibility of reusing recycled aggregates in the production of hot mix asphalt

The use of aggregates resulting from destroying concrete as a substitute for natural aggregates in the production of hot mix asphalt for roads with high traffic loads reduces natural consumption and the amount of scattered waste. The study was conducted by designing the hot mix asphalt using the Marshall method with different proportions of recycled aggregate. The results showed an improvement in the stability, flow and indirect tensile tests of the aggregate compared to the conventional mixture. An increase in the recycle aggregate leads to an increase in the proportion of air voids, but it also leads to a decrease in the proportion of voids in the aggregate and asphalt-filled voids. The optimum bitumen content increases with the amount of recycled concrete. Recycled aggregate can be used as a substitute for natural aggregate in hot mix asphalt design successfully. The study found that increasing the percentage of recycled concrete (RCA) in hot bituminous mixtures led to an increase in air voids (VA) and a decrease in voids in mineral aggregates (VMA) and voids filled with asphalt (VFA). However, these percentages decreased with the increase in RCA due to the behavior of the recycled aggregates under load. The optimum bitumen content (OBC) also increased with the increase in RCA. The asphalt mixture's resistance to tensile stress increased with the increase in RCA up to 50% and at 25˚C and RCA 40˚C by up to 8%. The process of using recycled aggregates as an alternative to natural aggregates in hot bituminous mixtures is applicable up to a certain percentage.

Effects of the Mixing Process on the Rheological Properties of Waste PET-Modified Bitumen

This paper analyses the key findings of a study devoted to PET-modified bitumen. The research program was run according to the D-optimal experimental plan based on a factorial design. Five factors, i.e., the type of polymer (source), the type of bitumen (qualitative factors), PET amount, mixing rate, and mixing temperature (quantitative factors), controlled the bitumen–polymer mixing process. The experiment included a series of determinations of bitumen’s rheological characteristics obtained by MSCR (Jnr, R) and G*/sin(δ) at 50 °C, 60 °C, and 70 °C. The low-temperature properties of the composite (critical temperature) were evaluated using a BBR test. The findings showed that bitumen modification with PET primarily reduced the creep susceptibility of the bituminous–polymer mixture. The low-temperature characteristics of the modified bitumen played a secondary but essential role. The amount of polymer and the mixing rate interacted with the temperature, significantly reducing the stiffness of the composite, while the type and amount of bitumen had a substantial effect on the results obtained in the BBR test. It is worth noting that when combining bitumen and plastomer, special attention should be paid to ensuring a high level of homogeneity of the mixture by controlling the parameters of the mixing process accordingly. The tests and analyses provided crucial models (GLM), which allowed for the prediction of the plastomer-modified bitumen’s low- and high-temperature properties. The resulting relationships between factors and the identification of their impact on the bitumen properties enable a better understanding of the process of bitumen modification with PET. The conclusions presented here serve as a basis for future optimisation of the modified bitumen composition. The performed studies indicate that the use of >3% plastomer in bitumen 70/100 allows for a reduction in its susceptibility (MSCR) to below 0.5 kPa−1, making it suitable for bituminous mixtures for high-traffic roads. No significant increase in critical temperature (BBR) was observed.

Performance Analysis of Industrial-Waste-Based Artificial Aggregates: CO2 Uptake and Applications in Bituminous Pavement

In order to raise the utilization rate of industrial waste and mitigate issues involving land resource occupation and environmental damage, in this study, industrial-waste-based artificial aggregates (IWAAs) were fabricated using steel slag powders, fly ash, and cement. They were processed under accelerated carbonation and were utilized in a bitumen mixture. During the experiment, the micromorphology, internal structure, and phase composition of IWAAs before and after accelerated carbonation were characterized using X-ray phase analysis, thermal analysis, and scanning electron microscopy (SEM); concurrently, the possibility of IWAAs being used as a partial substitute for natural aggregate to prepare bituminous mixture was qualitatively and quantitatively analyzed based on Marshall’s design procedure in combination with road performance tests and microcosmic analyses. The results indicated that the presence of carbonate crystals brought about by accelerated carbonation was the main phase composition inside the IWAAs, enhancing the microstructure densification and diminishing the immersion expansion and crushing values; this is due to the depletion of the interior Ca-based (e.g., f-CaO and Portlandite) and Mg-based (e.g., periclase and brucite) compounds together with the formation of cement hydration products. Additionally, the 12 h carbonation time obtained the optimum CO2-sequestration efficiency on the premise of satisfying the performance standard. The expansion rate and crushing value of the IWAAs decreased by 82.21% and 41.58%, respectively, whilst the anti-rutting properties, the moisture damage resistance, and the skid resistance rose by 31.92%, 5.59%, and 10.00%, respectively, in the IWAAs–bituminous mixture. This study lays a foundation for research on the CO2 sequestration and resource utilization of industrial wastes in bitumen mixtures.

Recycling of steel slag in sustainable bituminous mixtures: Self-healing performance, mechanism, environmental and economic analyses

The accumulation and disposal of steel slag (SS) is a growing problem with economic impact and environmental burden. This work aims to use SS to partially replace limestone to prepare sustainable self-healing steel slag bituminous mixtures (SSBM) to reduce maintenance costs and reduce greenhouse gas emissions. The damage-healing test, the microwave heating test of SSBM was carried out, and CT scanning was performed on SSBM before and after damage-healing. Cost-benefit analysis (CBA) was performed on the SSBM. The self-healing performance of SSBM is far better than traditional mixtures. The scale evolution of voids is the essential reason for the increase of fracture resistance of SSBM after healing. In the pre-crack (void) stage, the self-healing theory was improved based on the morphological repair theory of void interface. CBA results show that SSBM is economically and ecologically efficient. This work is helpful to the reuse of SS and the development of sustainable pavement.

Investigation of Physical and Chemical Properties of Bitumen Modified with Waste Vegetable Oil and Waste Agricultural Ash for Use in Flexible Pavements

The rapid growth of the world population and the rapid diversification of consumption habits due to technological advancements have increased waste production. An investigation of the effects of biomass products, such as waste vegetable oil and waste agricultural ash, on bitumen’s physical and chemical properties was conducted in this study. By recycling biomass products, this study aimed to improve the performance and stability of bituminous hot mixtures, optimize the number of additives, and create more economical designs. Using the Taguchi method, 0%, 2%, 4% by weight of waste vegetable oil and 0%, 3%, and 6% by weight of waste agricultural ash were added to 70/100 penetration pure bitumen with an orthogonal array of L9. For 10, 20, and 30 min, modified bitumen samples were prepared at 170 °C, 180 °C, and 190 °C with a constant mixing speed of 3000 RPM. The samples were tested for penetration, softening point, flash point, rolling thin film oven (RTFOT), FTIR, and Marshall Design stability and flow. Based on the obtained performance statistics, 95% confidence levels were assigned to the predictions. The stability and softening point values decreased as the oil content increased, while flash and penetration values increased. With increasing ash content, stability, flash, and softening point values increased, and penetration values decreased. Compared to oil and ash additives, mixing temperature and time had relatively little effect on the modification process. Overall, the optimum parameter levels were 4% for oil, 0% for ash, 170 °C for temperature, and 10 min for time.

Investigating the Impact of Polymer and Portland Cement on the Crack Resistance of Half-Warm Bituminous Emulsion Mixtures

Cold mix asphalt (CMA) is emerging as an environmentally friendly alternative to traditional hot mix asphalt (HMA). It offers advantages such as lower costs, reduced energy demands, decreased environmental impacts, and improved safety aspects. Among the various types of CMA, the cold bitumen emulsion mixture (CBEM) stands out. The CBEM involves diluting bitumen through emulsification, resulting in lower bitumen viscosity. However, this process has certain drawbacks, including extended setting (curing) times, lower early strength, increased porosity, and susceptibility to moisture. This study focuses on enhancing CBEM properties through the utilization of low-energy heat techniques, such as microwave technology, and the incorporation of a polymeric additive, specifically acrylic. These innovations led to the development of a novel paving technology known as a half-warm bitumen emulsion mixture (HWBEM). The research was conducted in two phases. First, the study assessed the impact of low-energy heating on the CBEM. Subsequently, it explored the combined effects of low-energy heating and the addition of an acrylic polymer. CBEM samples containing ordinary Portland cement (OPC) as an active filler were utilized in the sample manufacturing process. The effectiveness of these techniques in enhancing crack resistance was evaluated by analysing the results of the indirect tensile strength test. Notably, CBEM samples containing an amount of 2.5% of acrylic polymer and OPC exhibited the highest resistance to cracking. Furthermore, significant improvements were observed in their volumetric and mechanical properties, comparable to those of HMA.

Healing Evaluation of Asphalt Mixtures with Polymer Capsules Containing Rejuvenator under Different Water Solutions

Polymer Ca-alginate capsules with rejuvenator bring a high healing level for asphalt concrete under dry healing environments; however, the healing levels of bituminous mixtures containing capsules under water healing conditions are still unknown. In view of this, this study aimed at exploring the healing levels of asphalt concrete containing polymer capsules under various solution healing conditions following cyclic loads. This study involved the preparation of capsules, followed by the evaluation of their morphological characteristics, resilience to compression, thermal endurance, and rejuvenator content. The assessment of the healing properties of asphalt concrete utilizing capsules was conducted through a fracture–heal–refracture examination. This study conducted Fourier transform infrared spectrum experiments to determine the rejuvenator release ratio of capsules under dry conditions and the remaining rejuvenator content in extracted bituminous binder from capsule–asphalt concrete after solution treatment. Meanwhile, a dynamic shear rheometer was utilized to investigate the rheological characteristics of asphalt binder. Results revealed that the healing ratios of capsule–asphalt concrete beams under a dry healing environment were significantly higher than that of beams under various solution healing conditions, and the alkali solution has the worst effect on the improvement in healing ratio. The coupled impact of moisture intrusion and ion erosion resulted in an enhancement of complex modulus of asphalt binder while concurrently reducing its phase angle. Consequently, the restorative capacity of the asphalt binder was weakened.

A review study on sustainable utilisation of waste in bituminous layers of flexible pavement

The development of a new road has a variety of ramifications for the environment, using considerable quantity of materials and energy. Also, the cost of crude oil, which is the principal source of bituminous binder, has substantially grown in recent years. This has resulted to a rise in the overall price of bituminous blends. Developing innovative materials and technology to incorporate greener material, waste and recycled materials into the manufacturing cycle of bituminous mixes is a solution that enhances both sustainability and cost-efficiency of the bituminous pavement industries. Sustainable materials have increasingly been adopted in construction of roads nowadays because people are more concerned about its ramifications towards surroundings. However, people keep seeking to discover the most appropriate sustainable materials to be utilised in developing road pavement. In the current research, the two primary components of bituminous mixture i.e. bitumen and aggregates are focused and reviewed. Furthermore, the study presents a brief outline of several recycled materials which have been effectively used into bituminous layers of flexible pavement. Review findings suggest that the usage of secondary material not only offers an effective waste disposal approach but also minimise requirement for traditional material and lowers the total building cost. An effective and appropriate system of transportation is crucial for the development of any nation. The purpose of this review study is to establish the applicability and effectiveness of the waste material that has been used in the bituminous layers of flexible pavement.

Microwave self-healing characteristics of bituminous mixtures with different steel slag aggregate and waste ferrite filler

To improve crack propagation issues of bituminous mixtures in an eco-friendly way, steel slag (SS) and waste ferrite were partially substituted for aggregate and filler in the bituminous mixtures to enhance the self-healing performance (SHP) of the mixture through microwave heating (MH). Firstly, the electromagnetic parameters of ferrite filler (FF) and SS were tested by the vector network analyzer. Secondly, the thermal conductivity (TC) of ferrite filler bituminous mixtures (FFBM) and steel slag bituminous mixtures (SSBM) was tested based on the transient plane source. Subsequently, the MH surface temperature was measured on FFBM and SSBM, and the MH efficiency and uniformity were analyzed. Finally, the SHP of two types of bituminous mixtures under different conditions was analyzed. The results revealed that both FF and SS have significant magnetic loss, and the absorption performance of FF is better at the same frequency and thickness. The TC of SSBM is higher than FFBM, but due to the porous characteristics of SS, it tends to stabilize. The MH efficiency of FFBM is lower due to its volume ratio, but it has better uniformity. The self-healing rate of SSBM is higher at 40 s MH time, but FFBM can obtain a higher self-healing rate by extending the heating time. This work contributes to understand the difference between different types of suction materials self-healing of bituminous mixtures under MH.

Effect of different rejuvenation methods on the fatigue behavior of aged SBS modified asphalt

Reclaimed bituminous mixture can be used in new pavement after rejuvenation. Common rejuvenation method and reactive rejuvenation method can be used to restore the properties of aged SBS modified asphalt(ASMB). This work focused on the recovery effect of fatigue resistance for ASMB by different rejuvenation methods. The effect of common and reactive rejuvenation on the fatigue behavior of ASMB was investigated by multi-stress creep and recovery test, linear amplitude sweep test and fatigue-healing-fatigue test. The results show that, as compared with common rejuvenation method, reactive rejuvenation method is more conducive to restoring the creep recovery rate and the non-recovered creep compliance of ASMB. Linear amplitude sweep test indicates that reactive rejuvenated ASMB shows the good fatigue stress cracking resistance, the fatigue life of which at 2.5% and 5.0% strain levels is increased by 30% and 71% as compared with that of common rejuvenated binder. Meanwhile, the self-healing index of reactive rejuvenated ASMB is also enhanced by 28.7%, which indicates its better self-healing potential and fatigue damage resistance. Furthermore, the fatigue life of SMB is reduced by 77.7% after aging, while that of ASMB is extended by 93.5% after common rejuvenation, and the fatigue life of reactive rejuvenated ASMB is almost twice than that of common rejuvenated binder. It means that reducing the adverse effects of aged asphalt and reconstructing the broken SBS cross-linking structure during rejuvenation process of ASMB are all crucial for restoring its fatigue resistance.