Performance Of Bitumen Research Articles

Mechanism of asphalt concrete reinforced with industrially recycled steel slag from the perspectives of adhesion and skeleton

This research investigated the reinforcement mechanism of steel slag recycling in asphalt concrete from the perspective of adhesion and skeleton. Bonding performance between steel slag and bitumen was assessed by the calculation of coating area and peeling area, as well as the area detection by Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS). Computed Tomography (CT) scanning was used to determine the bitumen absorption characteristics of steel slag. Mechanical characteristics of steel slag mixture during compaction period and service period were evaluated by continuous compression test with Universal Testing Machine (UTM-25). A combination of CT scanning and image processing technology were used to quantify skeleton contact characteristics. The results indicated that bonding performance of bitumen with steel slag was obviously better than basalt after long-term erosion. The surface pores of steel slag absorbed excessive bitumen as anchoring and embedding effect, accounting for 20.24% of the total steel slag bitumen absorption in maximum. Steel slag skeleton of SMA gradation was found easily to be compacted during construction period and more resistant to loading during service period. In addition, there were more contact points in steel slag asphalt concrete, resulting that steel slag asphalt concrete had better stability. The contact points were different in different particle size ranges, and it was suggested that steel slag with particle size of 9.5–16.0 mm and 2.36–4.75 mm should be preferred.

A molecular dynamics analysis of the influence of iron corrosion products on the healing process of bitumen

Corrosion of iron materials in the asphalt concrete pavement occurs commonly when the bitumen film peels off, and the generation of corrosion products would affect the healing performance of bitumen. To identify the affection, this research focuses on the influence of iron corrosion products on the healing process of bitumen by molecular dynamics simulation. Firstly, bitumen model and iron corrosion products model were built. Then the healing systems of sandwich structure were constructed, and the simulated temperature were applied to reach equilibrium in the healing process with NVT ensemble (constant number of atoms, volume, and temperature). Dynamic movements of bitumen were characterized by appearance qualitatively. Healing rate of crack and healing rate of bitumen aggregation were held to evaluate the healing effect. Diffusion behaviors, internal force of motivation and interaction effect were also analyzed. The results indicate the duplicity of iron corrosion products in the healing process including the ease for bitumen climbing and the obstruction of bitumen movement. The comprehensive healing index demonstrated that iron corrosion products would reduce the healing degree, which was mainly caused by the obstruction effect and large internal stress generated by severe aggregation of bitumen in the limited space. From the perspective of crack closure and bitumen aggregation degree in the corrosion area, FeO healing systems were healed best, followed by Fe3O4, Fe2O3 and FeOOH. Furthermore, diffusion period of bitumen molecules on the surface of iron corrosion products during the healing process should be regarded as the important period affecting healing.

Characterising the modifying efficiency of polyphosphoric acid to bitumens with different oil sources

ABSTRACT To explore the properties and mechanism of different polyphosphoric acid (PPA)-modified bitumen, this research selected three bitumens with different oil sources and two PPAs with different relative H3PO4 contents (which are 105%, 115%, namely 105 and 115 grade PPA, respectively). A succession of tests and analyses was conducted to explore the performance of the PPA-modified bitumens. The physical performance test results show that PPA improves the high-temperature performance of the bitumens, and it has different modification effects on the three bitumens. When PPA reacted with the bitumen that has a higher content of polar components, the performance variation of the bitumen was higher than the other two kinds of bitumens. Furthermore, the 115-grade PPA seemed to have a better modified efficiency than that of the 105-grade PPA due to the longer molecular chain length. This also leads to the entanglement of molecular chains of PPA-modified bitumen was more significant with the 115-grade PPA. Therefore, the 115-grade PPA-modified bitumen shows a large asphaltene agglomeration in the AFM diagram.

Advanced testing and characterization of low-temperature cracking in bitumen and mastic

Low-temperature cracking is one of the most common failures in asphalt pavements, especially in cold regions. Accordingly, considerable amount of research has been performed in order to understand the low-temperature cracking mechanisms and to propose test methods for characterizing and determining cracking performance of bitumen and asphalt mixtures under freezing conditions. The existing test methods, however, require expensive equipment and skilled technicians; they are thus not well suited for routine tests. As a contribution to mitigate this situation, this study intends to investigate experimentally and characterize numerically the low-temperature cracking behavior of bitumen and mastic materials using a refined thermal cracking test method. The proposed method, the annular restrained cold temperature induced cracking (ARCTIC) test, allows to determine the low-temperature cracking properties of the mastic and bitumen with a relatively simple setup. In this paper, finite element (FE) modeling is used for evaluating the effect of test parameters on the temperature, stress and strain gradients induced in the specimen during the test. The ARCTIC test is employed to measure cracking temperatures of two bitumen and two mastic materials. The measurements repeatability is examined and the effect of bitumen type on the thermal cracking potential of bitumen and mastic is evaluated. FE modeling is employed to examine the effect of thermomechanical parameters on thermal cracking performance of the materials and to back-calculate fracture stress and strain from measurements. The results highlight the potential of the proposed test and analysis method for evaluation of low-temperature cracking in bitumen and asphalt mastic.

Development of a Framework for Assessing Bitumen Fatigue Cracking Performance under Different Temperatures and Aging Conditions

A full understanding of bitumen fatigue cracking behavior is extremely important as this phenomenon has a considerable influence on bituminous pavement performance. The current framework for assessing this asphalt binder property is inconsistent in ranking bitumen fatigue performance in terms of the failure definition and damage characteristic curve (DCC) analysis. This study used four different types of asphalt binders: neat asphalt (NA), self-healing thermoplastic polyurethane (STP)-modified bitumen, self-healing poly (dimethyl siloxane) crosslinked with urea bond (IPA1w)-modified bitumen, and styrene–butadiene–styrene (SBS)-modified bitumen (SBSB). All the bitumens were subjected to short-term and long-term aging, and they were also tested by utilizing the linear amplitude sweep (LAS) test and the simplified viscoelastic continuum damage (S-VECD) model. LAS and S-VECD procedures were used to apply the newly proposed and current frameworks in order to analyze bitumen performance. The current framework showed that the bitumens that used a higher number of loading cycles (N) to reach their failure points (Nf) failed to exhibit greater fatigue performances in terms of DCC analysis. The developed framework (mainly based on the damage intensity [S] instead of N) was used to solve the inconsistency between the failure definition and DCC assessment in ranking bitumen performance. Additionally, the current framework (failure criterion) presented two R2 values below 0.1, but the developed framework (failure criterion) showed that all R2 values were greater than 0.9. The developed framework represents a turning point because, for the first time, this type of procedure is mainly being based on S instead of N. Although further tests are needed to confirm its efficiency, it eliminates the inconsistency between the failure definition and DCC assessment.

The Effect of a Liquified Wood Heavy Fraction on the Rheological Behaviour and Performance of Paving-Grade Bitumen

Biomass is one the most abundant renewable energy sources, and it can be processed through different thermochemical methods to obtain oils that can replace the petroleum bitumen used in road construction. For the construction industry to accept the bitumen replacement with bio-oil, it is necessary to know its properties and determine the applicability of conventional testing methods. This research utilized a liquified wood heavy fraction (bio-oil) obtained from waste wood through an innovative thermochemical liquefaction process. The aim was to investigate a kind of bio-bitumen produced by blending this bio-oil with paving-grade bitumen. The rheological behaviour in a wide temperature range, the performance relative to fatigue cracking and permanent deformation sensitivity, and the evolution with oxidative ageing were evaluated for the bio-bitumen and paving-grade bitumens. The bio-oil significantly affected the rheological behaviour of bitumen through an overall decrease in the phase angle and by failing the time–temperature superposition principle. The strong elastic response of the bio-bitumen improved resistance to fatigue and permanent deformation accumulation; however, resistance to oxidative ageing declined. Linear viscoelastic rheological indicators proposed in the literature to assess the material’s performance showed a similar trend of variation with oxidative ageing for bio-bitumen and paving-grade bitumen, though the indicators’ values could not be directly compared.

Preparation and Performance of Bitumen Modified by Melt-Blown Fabric of Waste Mask Based on Grey Relational and Radar Chart Analysis.

To effectively utilize waste mask materials in road engineering and minimize resource waste, the melt-blown fabric (MBF) of waste masks was utilized to modify the virgin bitumen. The preparation process of MBF-modified bitumen was investigated, and the physical and rheological properties of bitumen were measured. Subsequently, the blending mechanism during preparation and the dispersion morphology of the modifier were explored. Finally, the pavement performance of the mixture was investigated, and a radar chart analysis was performed to quantitatively assess the effects of MBF modification. Results suggested that the recommended preparation process of shear time, shear rate, and shear temperature was 170 °C, 4000 r/min, and 15 min, respectively. MBF enhanced the high-temperature stability of the binder and weakened the temperature susceptibility. The modification was primarily a physical process. No network structure and agglomeration formed in the bitumen after modification. The addition of MBF significantly improved the resistance of the asphalt mixture to a high-temperature deformation and water damage but harmed its low-temperature crack resistance. The comprehensive assessment results of 0% (f1), 1% (f2), 3% (f3), and 5% (f4) MBF to improve the properties of the mixture were in the following order: f3>f4>f2>f1, where the impact of 3% MBF was the most significant, followed by 5% and 1% MBF.

Review of Mixing Mechanism and Performance of Natural Rubber with Bituminous Materials

Road degradation is a common problem in Malaysia which caused by weather changes, expanding loads as well as the effects of ageing, moisture and temperature results in high maintenance expenses on conventional bitumen pavement. Therefore, it has been recommended on the modification of bitumen as a substitute technique to address this issue and extend the pavement’s lifespan. This study addresses the inadequacy of existing solutions by focusing on the direct mixing approach and the use of pre-treatment using chemical solvent and some additives specifically on epoxidized natural rubber, natural rubber latex and cup lump natural rubber (CLNR). Additionally, this study intends to give a brief summary of how bitumen performance is improved by the inclusion of additives or modifiers by emphasizing the key attributes of modified bitumen after the addition of modifiers. Further information is also provided on the quantity and application method of each addition in order to determine the ideal value for different applications. This study will examine the use of several additives based on past research, such as polyphosphoric acid, Zychotherm, as well as the use of toluene and xylene to maintain the homogeneity of the rubberized bitumen. Studies on the usage of cup lump natural rubber (CLNR) are not common, thus future study should investigate more closely at CLNR and its mixing technique. This research contributes to the field by providing insights into the practical application of modified bitumen for sustainable road construction, especially in regions with a significant rubber industry.

Enhancing aged SBS-modified bitumen performance with unaged bitumen additives

This study investigated the performance of SBS-modified bitumen (SBSMB) after aging and rejuvenation by utilizing macroscopic performance and microscopic characterization methodologies. The blending of aged SBS-modified bitumen (SBSPAV) with different proportions of SBSMB or 80–100 penetration grade base bitumen (90BB) was performed to produce SMB-rejuvenated bitumen (a blend of SBSMB and SBSPAV) and 90BB-rejuvenated bitumen (a blend of 90BB and SBSPAV). To evaluate high-temperature rutting behavior, multiple stress creep recovery (MSCR) tests were conducted on the binders, and the outcomes were analyzed using the Burgers model to elucidate their viscoelastic behaviors. Low-temperature performance was assessed using an asphalt binder cracking device (ABCD). Furthermore, the microscopic structure, roughness, and Young's modulus of the binders were investigated using an atomic force microscope (AFM). Thermal stability was assessed using a thermogravimetric analyzer (TGA). The findings indicated that SMB-rejuvenated bitumen exhibited favorable resistance to high temperatures and the ability to withstand heavy traffic loads. The stress sensitivity of 90BB-rejuvenated bitumen surpassed that of SMB-rejuvenated bitumen. The high-temperature performance rating of 90BB-rejuvenated bitumen displayed a continuous decline, indicating poor load-bearing capacity. Regardless of the unaged bitumen type, higher doses of unaged bitumen led to a gradual decrease in the rejuvenated bitumen's cracking temperature, indicating the enhancement of low-temperature performance of SBSPAV. However, both SMB-rejuvenated bitumen and 90BB-rejuvenated bitumen fell short of matching the performance level of pure SBSMB. AFM outcomes demonstrated that with increasing SMB dosage, the number of bee-like structures initially decreased before rising again, coupled with an increase in their volume. Conversely, an increase in 90BB dosage led to a gradual reduction in bee-like structures, accompanied by increased volume. The roughness of both SMB-rejuvenated bitumen and 90BB-rejuvenated bitumen exhibited improvements compared to SBSPAV, suggesting enhanced adhesion performance of the rejuvenated bitumen. TGA results unveiled lower thermal stability in 90BB-rejuvenated bitumen in comparison to SMB-rejuvenated bitumen. This study introduces a novel perspective on the design of SBS-rejuvenated bitumen.

Feasibility investigation of using waste laminated packaging as bitumen performance enhancer

Millions of tons of laminated packaging are extensively utilized in aseptic food packaging due to its advantages in transporting and storing liquid foods, leading to the annual generation of waste laminated packaging (WLP). To address this concern, this study processes WLP recycled from milk and fruit juice packages into particles. The properties of WLP-modified bitumen were characterized through conventional and rheological tests, and the results were compared with those of the base bitumen. The tests reveal that the addition of WLP increases the softening point and peak force while decreasing penetration and ductility. Additionally, higher WLP content results in a larger modification index, higher failure temperature, lower non-recoverable creep compliance, and lower stress sensitivity. Furthermore, the stabilizing effect of low-density polyethylene in WLP, combined with the complete cross-linking of cellulose fibers, contributes to enhancing the fatigue life of the bitumen.

Study on low-temperature performance of bitumen, mastic, and asphalt mixture

This research aimed to evaluate the effect of hot mix asphalt components on its low-temperature performance using multiphase analysis. Twelve mixtures, along with corresponding bitumens and mastics were tested with a Bending Beam Rheometer (BBR) at temperatures of −16, −22, and −28°C. A new shift factor, based on creep stiffness master curves, was defined to investigate the relationship between bitumen, mastic, and mixture performance at the reference temperatures of −16°C and −22°C. Results showed that the type of aggregate, bitumen, F/B ratios, and mastic affect the low-temperatures performance of the mixture. The constructed master curves indicated a consistent trend between the low-temperature crack resistance of mastic and the corresponding mixture, although it was observed that a mixture with lower creep stiffness did not necessarily have mastic with lower creep stiffness. A correlation was established between mastic properties and mixture creep stiffness, achieving a 0.9 correlation coefficient for validation data.

Eco-friendly asphalt mixtures: examining the performance of PE pyrolytic wax-modified bitumen for road construction

Eco-friendly asphalt mixtures: examining the performance of PE pyrolytic wax-modified bitumen for road construction

Characterization of aged bitumen recovered from in-situ polymer-modified HMA and WMA using advanced technologies

The growing attention of public opinion towards the environment has prompted, in the last decades, to find eco-sustainable and economic alternatives to the traditional productions of hot-mix asphalt (HMA). Under these auspices, the use of warm mix asphalt (WMA) technology applied to mixtures containing reclaimed asphalt (RA) has grown, also due to the well-proven advantages in terms of plant odor emissions and improved working conditions. In addition, it is now known that the mechanical performance of WMAs is completely comparable, even superior in some cases, to that of HMAs. However, to date, there is no comparison in terms of long-term performance of bitumens used in full-scale pavements laid with the two different technologies. Therefore, the aim of this research is to evaluate the oxidative and rheological state of four bitumens recovered from different layers of a full-scale pavement prepared with WMA and HMA technologies and set up a methodology tool set for investigating the physicochemical properties of bitumens. An in-depth laboratory investigation, carried out through physicochemical and rheological tests, has shown that the bitumens used in WMA mixtures are characterized by less oxidation than HMA ones (which are characterized by longer relaxation and glass transition times) and the Styrene-Butadiene-Styrene (SBS) polymers inside them are less degraded and still contribute positively to the rheological response even after five years in service, demonstrating the ability of the chemical additive to act as possible “sacrificial agent”, safeguarding the rheological characteristics of polymer modified bitumens (PMBs).

Improving anti-aging performance of terminal blend rubberized bitumen by using graft activated crumb rubber

Abstract The appearance of terminal blend rubberized bitumen (TB) has improved a series of defects of traditional rubber bitumen, such as high viscosity, poor storage stability. Therefore, its wide application prospect is self-evident. However, different degrees of thermal-oxidative aging problem still exist in the process from production to use of TB, which seriously affects the service life of pavement. To improve the anti-aging performance of TB, grafting activated crumb rubber (GACR) was obtained by using acrylamide, and then compounded with TB. Firstly, TB was prepared in the self-developed nitrogen protection device. Secondly, GACR modified bitumen (GACR-MB), TB/CR composite modified bitumen (TB/CR) and TB/GACR composite modified bitumen (TB/GACR) were developed in the atmospheric environment. Finally, the performance of four kinds of crumb rubber modified bitumens before and after aging was compared and analyzed by testing high and low temperature rheological properties. The results show that GACR slowed down the formation rate and aggregation degree of asphaltenes and other macromolecular substances, and TB/GACR showed excellent aging resistance.

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.

Unraveling the critical indicators for evaluating the high-temperature performance of rejuvenator-aged bitumen blends

This study aims to systematically investigate the influence of rejuvenator type/dosage and the aging degree of bitumen on the rutting resistance, flow behavior, and elastic/creep potential of rejuvenated bitumen at high temperatures. The rutting parameter (G*/sinδ), rutting failure temperature (RFT) from Linear viscoelastic test (LVE), zero-shear viscosity (ZSV) from flow test, recovery percentage (R0.1, R3.2), creep compliance (Jnr0.1, Jnr3.2), and stress sensitivity parameters (Rdiff, Jnrslope) from multiple stress creep and recovery (MSCR) tests of rejuvenated bitumen are characterized. The results reveal that bio-oil rejuvenator weakens the high-temperature performance of aged bitumen maximally, followed by engine-oil and naphthenic-oil, while aromatic-oil rejuvenated bitumen exhibits the best rutting, flow, and creep resistance. The RFT index can most effectively evaluate and differentiate the rejuvenation efficiency of various rejuvenators on the high-temperature performance, which correlates well with ZSV, R3.2, Jnr0.1, Jnr3.2, Rdiff, and Jnrslope indices. Therefore, the RFT index is recommended as the critical indicator for evaluating the high-temperature performance of rejuvenated binders. The flow and MSCR characteristics of rejuvenated bitumen can be predicted based on RFT values. The determination of critical indicators is beneficial to compare the rejuvenation effectiveness of variable rejuvenators on the high-temperature performance of aged bitumen.

Performance and Mechanism of High-Viscosity and High-Elasticity Bitumen (HVE-MB) Modified with Five Additives

In order to improve the viscoelasticity of bitumen, several modifiers were compounded with it, including SBS, reclaimed rubber powder, tackifier, plasticizer, and oil stabilizer, to produce High-viscosity and High-elastic Modified Bitumen (HVE-MB). The viscoelasticity and various physical and rheological properties of the bitumen were evaluated using a number of factors, such as dynamic viscosity at 60 °C, elastic recovery, penetration, softening point, ductility, and DSR. By comparing different types of modifiers and the content of SBS, it was found that the viscoelasticity of the original bitumen was significantly improved by adding the modifiers. In comparison to the original bitumen, the dynamic viscosity of the HVE-MB increased by more than 110 times, the elastic recovery rate more than doubled, the softening point and ductility improved, and the penetration decreased. As the content of SBS increased, the improvement in the properties became more significant. The workability of HVE-MB satisfies the requirement of less than 2.5 °C by adding the suitable dosage of stabilizer. On the other hand, the content of SBS can be adjusted based on the specific requirements. It is a sustainable and economic way to use the reclaimed rubber powder to improve the technical performance of bitumen.

Bio-polymer modified bitumen

Bitumen is a key constitutive material in asphalt pavements. It binds together the rock scaffolding of a pavement. Bitumen provides asphalt pavement with flexibility and enables it to respond to traffic loading and return to its original condition after the loading, i.e. bitumen restores/repairs the damage. In Porous Asphalt (PA) or Stonemastic Asphalt Mix (SMA) asphalt mixtures, due its open graded structure, bitumen modifiers are used to improve or restore bitumen physical and mechanical performance. Traditionally bitumen modifiers are made with products of crude oil, such as: ethylene vinyl acetate (EVA) copolymers and styrene–butadiene–styrene (SBS). As crude oil production declines and the environmental and financial costs of crude oil extraction increase, there is a need to identify environmentally sustainable alternatives to use in bitumen. Bitumen modifiers generated from biological sources offer an environmentally friendly and economically viable alternative to crude oil based bitumen modifiers. This paper describes how PHBV (poly-3-hydroxybutyrate-co-3-hydroxyvalerate), a bio-based co-polymer, might be used as an alternative bitumen modifier. The effect of PHBV on 70/100pen was investigated for this paper. The chemical and physical effect of the PHBV on the bitumen performance was investigated using Gel Permeation Chromatography, Fourier Transformed Infrared Spectroscopy, Differential Scanning Calorimetry, microscopic imaging and Dynamic Shear Rheometer tests. The results indicate that PHBV has significant potential as a bitumen bio-polymer modifier.

Hydrothermal carbonization of waste wood: Sustainable recycling of biomass by-products and novel performance enhancer for bitumen

Recycling biomass by-products into bitumen is one of the most effective ways to develop sustainable pavements. To cope with the shortage of petroleum resources and improper disposal of discarded biomass, the hydrothermal carbon (HTC) produced by hydrothermal carbonization of waste wood was adopted to reduce the consumption of bitumen and enhance the performance of bitumen, and the mechanical performances and working mechanism of hydrothermal carbon-modified bitumen (HTCMB) were investigated in this study. The results indicate that HTC significantly enhances bitumen's high-temperature and fatigue properties. When the content of HTC is not more than 3%, its effect on the low-temperature cracking resistance of bitumen can be ignored. The addition of HTC absorbs the polar components in bitumen, thus promoting the dispersion of polar components and effectively preventing the mutual aggregation and crystallization of wax components and asphaltenes in bitumen. The excellent mechanical properties of HTCMB can be attributed to the irregular fibrous composition and porous structures of HTC, which play a good role in reinforcing and connecting the bitumen matrix and dramatically enhances the interaction with bitumen. This study proposes a win–win solution to the shortage of petroleum resources in road engineering and the improper disposal of discarded biomass.

Lifetime Performance of Polymer-Modified Bitumen in Swedish Roads Evaluated With Survival Analysis

This study uses survival analysis to estimate the lifetime of Swedish asphalt paved roads. The roads were separated by binder type, such as unmodified bitumen and polymer-modified bitumen (PMB). Road pavements with PMB were compared to equivalent roads with regard to annual average daily traffic, heavy vehicles, road type, road width, speed limit, construction year, region, bearing capacity, pavement type, stone size, and rut bottom distance. The analysis was based on almost 500,000 records of pavement maintenance and road condition measurements from the Swedish Transport Administration’s Pavement Management System database, dating back as far as the 1970s. The results showed that PMB in the surface layer was expected to extend road lifetimes by 15% compared with bitumen. PMB in the underlying layer gave an 8% increase in life expectancy compared with unmodified bitumen. PMB in both layers gave a 24% increase in expected road lifetime compared with unmodified bitumen in both layers.