Bitumen and Bitumen Modification: History
View Latest Version
Please note this is an old version of this entry, which may differ significantly from the current revision.
Subjects: Polymer Science
Contributor:
Michele Porto

According to the European specification (EN 12597), bitumen is defined as a virtually involatile, adhesive, and waterproofing material derived from crude oil, or present in natural asphalt, which is completely or nearly completely soluble in toluene, and very viscous or nearly solid at ambient temperatures. It is well-accepted that the original characteristics of bitumen are highly dependent on its production and processing procedure, as well as bitumen crude oil characteristics. Good crude oils and proper distillation processes can enhance bitumen properties.

  • polymer-modified bitumens (PmBs)
  • chemical structure
  • microstructural systems
  • spectroscopy
  • compatibility

1. Introduction

1.1. Bitumen Functionality

According to the European specification (EN 12597), bitumen is defined as a virtually involatile, adhesive, and waterproofing material derived from crude oil, or present in natural asphalt, which is completely or nearly completely soluble in toluene, and very viscous or nearly solid at ambient temperatures [1]. It is well-accepted that the original characteristics of bitumen are highly dependent on its production and processing procedure, as well as bitumen crude oil characteristics [2]. Good crude oils and proper distillation processes can enhance bitumen properties. Generally, heavier crude oil gives higher bitumen yields [3]. Therefore, having a complete knowledge on the bitumen characteristics from different aspects is of paramount importance. This knowledge proves to be more important when, for some bitumen applications, some difficulties such as discontinuity in phase, mal-dispersion, and instability with polymers/additives make it challenging in the production and application of bituminous materials.
From a commercial point of view bitumen is a low-cost thermoplastic material that has been widely used in roofing and pavement application, paving mixtures, and industrial products for a long time. In both paving and industrial applications, the bitumen should be resistant to climate and more demanding traffic loads, for which reason rheological properties play a key role in different aspects [4][5][6]. From a functional point of view, the bitumen has to be fluid enough at high temperature (≈160 °C) to be pumpable and workable to allow for a homogeneous coating of aggregate upon mixing. Moreover, it has to be stiff enough at high temperatures to resist rutting (according to the local temperatures, ≈60 °C). Finally, it must remain soft and elastic enough at low temperatures to resist thermal cracking [4]. All the mentioned requirements are almost opposite, and most of the available neat bitumens would not provide all the needed characteristics together. Moreover, in some applications, the performance of conventional neat bitumens may not be satisfactory considering the required engineering properties because it is brittle in a cold environment and softens readily in a warm environment. This limited performance temperature range is the main drawback to neat bitumen, limiting its use for both roofing and road paving applications. In addition, as the traffic speed and load has dramatically increased, unplanned overloading has notably shortened the life of asphalt pavements, increasing its costs of maintenance and risks to users. Hence in order to enhance the performance properties of neat bitumen, to date, a variety of additives have been introduced and some have been used successfully for many applications. Modifiers and additives have been used to boost bitumen performance include: polymers, chemical modifiers, extenders, oxidants and antioxidants, hydrocarbons, and anti-stripping additives.

1.2. Bitumen Chemistry

From a chemical point of view, bitumen is defined as a viscous viscoelastic liquid (at room temperature) consisting essentially of hydrocarbons and their derivatives, which is totally soluble in toluene, substantially non-volatile, and softens gradually when heated [7]. It comprises a very great number of molecular species that vary widely in polarity and molecular weight [8][9]. Elemental analysis show that bitumen composition is primarily determined by its crude oil source and it is difficult to give a specific geographical generalization [10][11] (many suppliers also mix bitumen from different sources as well). This has been shown in a wide research by SHRP (Strategic Highway Research: Special Report) [12]. Based on this report, the main constituents of bitumen are carbon, which varies from 80 to 88 wt% and hydrogen ranging from 8 to 11 wt%. In addition, Heteroatoms and transition metal atoms (principally vanadium and nickel) are generally presents: sulfur (0 to 9 wt%), nitrogen (0 to 2 wt%), oxygen (0 to 2%), vanadium up to 2000 ppm, and nickel up to 200 ppm [10][13][14].
From a molecular point of view, the main compounds of the polar heteroatoms above are: sulphides, thiols and sulfoxides, ketones, phenols and carboxylic acids, pyrrolic and pyridinic compounds, and most metals form complexes such as metalloporphyrins [14]. Molecular weight distribution analysis shows that bitumen is a complex mixture of about 300 to 2000 chemical compounds (medium value 500–700) making a complete chemical characterization very difficult. For this reason, bitumen is generally fractionated by simpler methodologies, which allow two principal constituents to be identified:
  • Asphaltenes
  • Malthenes (also called petrolenes)
Maltenes are then classified into saturate, aromatic, and resin, which together with asphaltene are known as the bitumen SARA (Saturate, Aromatic, Resin, Asphaltene) fraction. The relative abundance of the SARA fractions allows the bitumen chemical composition to be related with its internal structure and some of its macroscopic properties [15]. However, it should be noted that changes in experimental conditions (especially eluent nature) significantly affect the proportion of every bitumen fraction [10][16]. It is, therefore, important to specify the experimental setup condition for comparing the various chemical compositions of bitumen, even though they show some common features and overall properties that remain substantially unchanged.

2. Bitumen Polymers

Polymers are macromolecules synthesized through chemical reaction between smaller molecules (monomers) to form long chains. The physical properties of the resulting polymer are determined by the chemical structure of the monomers and by their sequence inside the polymer. A combination of two different monomers that can be in a random or block arrangement gives a so-called copolymer. Polymers include a broad range of modifiers with elastomers and plastomers being the most commonly-used types. Polymer-modified bitumens (PmBs) are produced by the mechanical mixing or chemical reactions of a bitumen and one or more polymer in a percentage usually ranging from 3% to 10%, relatively to the weight of bitumen. In the first case, the mixtures are said to be simple, because no chemical reactions occur between the two partners in the system. In this case, the polymer is considered as a filler which gives specific properties to the mixture. In the second case, the mixtures are said to be complex, because chemical reactions or some other interaction occurs between the two partners in the system [17].
Modified bitumens are characterized as a two-phase system: bituminous, prevalently as asphaltenic matrix, and polymeric matrix, which has been investigated from two different points of view.: (1) the complex interaction mechanism between bitumen and additive and (2) the influence of different type of bitumen modifiers aiming to study the rheological performance characteristics, temperature sensitivity, morphology, thermal behavior storage stability, and aging of the resulting PmBs.
From a bitumen/polymer interaction mechanism point of view, according to Polacco et al. [18], polymer modification results in a thermodynamically unstable but kinetically stable system in which the polymer is partially swollen by the light bitumen components (maltenes) and can swell up to nine times its initial volume [19]. Competing for bitumen’s light fractions, polymers tend to induce the micelles aggregation of the asphaltenes or to increase their degree of association, according to the nature of the original bitumen. At high temperatures, a relatively low viscosity of the melted micro-heterogeneous polymer-modified bitumen allows the substances with similar structure and polarity to form their domains: the swollen polymers and the asphaltenes. However, the thermodynamic instability of this system induces a phase separation (or sedimentation) under the influence of the gravitational field. Therefore, associated asphaltene micelles can settle to the bottom of the blend during static hot storage. According to this mechanism, the degree of phase separation of polymer modified binders can be influenced by storage conditions such as temperature and time. As shown by Lu et al., the phase separation will mainly be governed by the nature of the base bitumen and the characteristics and content of the polymer [8]. To date, different types of additives and polymers have been used for bitumen modification [20]. Table 1 summarizes the most common types of additives used as bitumen modifiers.
Table 1. Examples of additives used to modify bitumen (reconstructed from [20] with the permission of Thomas Telford).

Type of Modifier

Examples

Abbreviation

thermoplastic elastomers

Styrene–butadiene elastomer

SBE
 

Styrene–butadiene–styrene elastomer (linear or radial)

SBS
 

Styrene–ISOPRENE–STYRENE elastomer

SIS
 

Styrene–ethylene–butadiene–Styrene elastomer

Ethylene-propylene-diene terpolymer

SEBS
 

Isobutene–isoprene random copolymer

IIR
 

Polyisobutene

PIB
 

Polybutadiene

PBD
 

Polyisoprene

PI

latex

Natural rubber

NR

thermoplastic polymers

Ethylene–vinyl acetate

EVA
 

Ethylene–methyl acrylate

EMA
 

Ethylene–butyl acrylate

EBA
 

Atactic polypropylene

APP
 

Polyethylene

PE
 

Polypropylene

PP
 

Polyvinyl chloride

PVC
 

Polystyrene

PS

thermosetting polymers

Epoxy resin

  
 

Polyurethane resin

PU
 

Acrylic resin

  
 

Phenolic resin

  

chemical modifiers

Organometallic compounds

  
 

Sulfur

S
 

Phosphoric acid, polyphosphoric acid

PA, PPA
 

Sulfonic acid, sulfuric acid

  
 

Carboxylic anhydrides or acid esters

  
 

Dibenzoyl peroxide

  
 

Silanes

  
 

Organic or inorganic sulfides

  
 

Urea

  

recycled materials

Crumb rubber, plastics

  

fibers

Lignin

  
 

Cellulose

  
 

Alumino-magnesium silicate

  
 

Glass fibers

  
 

Asbestos

  
 

Polyester

  
 

Polypropylene

PP

adhesion improvers

Organic amines

  
 

Amides

  

anti-oxidants

Phenols

  
 

Organo-zinc or organo-lead compounds

  

natural asphalts

Trinidad Lake Asphalt

LA
 

Gilsonite

  
 

Rock asphalt

  
In Table 2 are summarized the most common used modifiers found in the literature, which are discussed in this paper.
Table 2. Different categories of polymers mainly used in bitumen modification.

Thermoplastics Polymers

Polyethylene (PE)

Polypropylene (PP)

Ethylene-Vinyl-Acetate (EVA)

PVC

EBA

Thermoplastic Elastomers

Styrene-Butadiene-Styrenhe-Block copolymers (SBS)

Styrene-Isoprene-Styrene-Block copolymers (SIS)

Thermosets

Epoxy resin

Polyurethane resin

Acrylic resin

Phenolic resin

Natural and Synthetic Rubbers

Styrene-Butadiene rubber (SBR)

Natural rubber

Polydiolefins

Reclaimed Tire rubber

Bitumen Chemical Modifier

Sulphur (S)

Polyphosphoric acid (PPA)

Reactive Polymers

Maleic Anhydride (MAH)

Nanocomposite Modifiers

Warm Mix Asphalt methodology

 
Each of these groups associate with different pros and cons as a bitumen additive. In addition to the large group of polymers, other bitumen modifiers, such as polyphosphoric acid (PPA), sulfur, maleic anhydride, and different kinds of clays, have been introduced and experienced, in this respect, some success.

3. Bitumen Chemical Modifiers

Systematic investigation of mechanical, rheological, and aging properties, temperature sensitivity, morphology, and thermal behavior of different PmBs has shown some advantages and drawbacks [6][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. First of all, it has been shown that polymer modification improves some of the properties of bitumen, such as better elastic recovery, higher cracking resistance at low temperatures, and higher rutting resistance at high temperatures [36][21][26]. Secondly, some drawbacks have been observed, such as thermal instability and PmB’s phase separation problems [37][38]. The first attempts to overcome the PmB’s drawbacks were started in the early 1990s, when Giavarini et al. claimed that PmBs could be stabilized by adding polyphosphoric acid (PPA) [39]. They also believe that PPA could help to improve storage stability of polypropylene-modified bitumens by changing the bitumen structure from sol to gel. From then, various attempts have been made to remove the drawbacks of the PmBs. In addition to physical blends of bitumens and polymers, another way to improve the binder properties is through chemical modification, which uses the chemical agent as an additive to modify the characteristics of pure bitumen.
To date many chemical agents have been introduced for the target of bitumen modification, such as: organo-metallic compounds [40][41], sulfur (S) [42][43][44][45][46][47][48][49], polyphosphoric acid (PPA) [50][51][52], sulfonic acid [53], carboxylic anhydrides [54][55][56], silanes [57][58], thiourea dioxide [59], nanocomposite-modified bitumen [60][61][62][63][64][65][66][67][68], and reactive polymers [69][70][71][72][73][74][75][76][77][78][79][80][81][82][83]. However, from the above-mentioned chemical compounds only a few of them have been used practically. Sulfur (S), polyphosphoric acid (PPA), reactive polymers, maleic anhydride (MAH), and polymer/clay or polymer/layered silicate (PLS) nanocomposites are the most common chemical agents.

4. PmBs in Warm Mix Asphalt (WMA) Technology

A new kind of polymer-modified bitumen technology has been introduced in recent years. It combines the classic ones (PmB) with the warm mix asphalt technique (WMA). One of the methodologies employed to shift from hot mix asphalts to warm ones is based on the use of waxes. This is due to the fact that above their melting temperature, they act as plasticizers, while at low temperatures they crystallize and act as fillers [4][84][85]. While the PmB is well consolidated the WMA is relatively new, but rapidly growing, due to its economic and environmental advantages. Compared with classic hot mix asphalts (HMA), warm mix ones, in general, are characterized by lower fuel consumption and costs, lower production of greenhouse gases, fumes, and odors, which improve the environmental impact and working conditions, extension of haul distances, and good workability during laying and compaction [84]. Although naturally present as constitutive components of all crude oil products [86][87] and studied in the technical literature, where bitumen wax content [88][89][90], crystallization properties [91], chemical structure [92][93], and influences on bitumen and bitumen mixture properties [85][88][94][95][96][97][98][99] were analyzed, waxes affect the binder performances. For example, wax melting can soften bitumen at high service temperature, reducing rutting resistance of the pavement, while at low temperatures wax crystallization can increase stiffness and sensitivity to fatigue and thermal cracking [84][88][99]. Nowadays there is an increase development about warm polymer modified bitumen which can maintain the advantages of both technologies (WMA and PMB) although this is not an easy task because waxes used as warm modifiers reduce the high temperature viscosity while increasing the low temperature stiffness and polymers do basically the contrary [84]; simply adding the two modifiers does not guarantee the enhancement of bitumen properties like those obtained by adding single ones. For example, a ternary mixture bitumen/polymer/wax has significantly different properties (like viscoelasticity) from those predictable by superposing the effect of wax and polymer only and the final warm effect and performances of the binder will be determined by the interactions between the three components. Scientific studies on this ternary mixture are still limited. Edwards et al. [100] for example, studied the addition of paraffinic waxes to a polymer-modified mastic bitumen, showing that a 4% wax addition improves workability of the mastic bitumen without affecting its performances. Kim et al. [101][102] studied the artificial long- and short-term aging of a PmB mixed with wax additives. Other studies analyzed the properties and pavement performance, compacting temperatures, long-term performance [103], fatigue characteristics [4], thermo-mechanical properties [104], and viscosity and rheological properties [105]. Rossi et al. [84] conducted a preliminary investigation by mixing bitumen, SBS, and three typologies of wax chosen among the three categories: paraffinic (obtained by Fischer-Tropsch process), partially oxidized and maleic anhydride functionalized. By morphological and calorimetric analyses and solubility tests they were able to characterize blend behavior related to wax type. In particular, they found that paraffinic waxes preferentially reside in the polymer-rich phase and slightly enhance the bitumen polymer compatibility. Partial oxidation tends to aggregate with the asphaltene rich phase reducing compatibility with the polymer, while functionalized wax, although not clear where they are located, has a considerable compatibilizing effect strongly altering the colloidal equilibrium of the bitumen polymer blend.

This entry is adapted from the peer-reviewed paper 10.3390/app9040742

References

  1. European Committee for Standardization EN 12597: Bitumen and Bituminous Binders-Terminology; European Committee for Standardization: Brussels, Belgium, 2000.
  2. Paliukait, M.; Vaitkusa, A.; Zofkab, A. Evaluation of bitumen fractional composition depending on the crude oil type and production technology. In Proceedings of the 9th International Conference “Environmental Engineering” Selected Papers, Vilnius, Lithuania, 22–23 May 2014.
  3. Read, J.; Witheoak, D. The Shell Bitumen Handbook, 5th ed.; Thomas Telford Publishing: London, UK, 2003.
  4. Lesueur, D. The Colloidal Structure of Bitumen: Consequences on the Rheology and on the Mechanisms of Bitumen Modification. Adv. Colloid Interface Sci. 2009, 145, 42–82.
  5. Olli-Ville, L. Low-Temperature Rheology of Bitumen and Its Relationships with Chemical and Thermal Properties. Ph.D. Thesis, School of Engineering, Aalto University, Espoo, Finland, 2015.
  6. D’Melo, D.; Taylor, R. Constitution and Structure of Bitumens. In The Shell Bitumen Handbook, 6th ed.; Hunter, R.N., Self, A., Read, J., Eds.; ICE Publishing: London, UK, 2015; ISBN 978-0727758378.
  7. McNally, T. Introduction to polymer modified bitumen (PmB). In Polymer Modified Bitumen Properties and Characterisation, 1st ed.; McNally, T., Ed.; Woodhead Publishing: Sawston, UK, 2011.
  8. Lu, X.; Isacsson, U.; Ekblad, J. Phase Separation of SBS Polymer Modified Bitumens. J. Mater. Civ. Eng. 1999, 11, 51–57.
  9. Petersen, J.C. Chemical Composition of Asphalt as Related to Asphalt Durability: State of the Art. Transp. Res. Rec. 1984, 999, 13–30.
  10. Branthaver, J.F.; Petersen, J.C.; Robertson, R.E.; Duvall, J.J.; Kim, S.S.; Harnsberger, P.M.; Mill, T.; Ensley, E.K.; Barbour, F.A.; Schabron, J.F. Binder Characterization and Evaluation-vol 2 Chemistry; SHRP Report A-368; National Research Council: Washington, DC, USA, 1994.
  11. Mortazavi, M.; Moulthrop, J.S. SHRP Materials Reference Library; SHRP report A-646; National Research Council: Washington, DC, USA, 1993.
  12. Strategic Highway Research: Special Report 260. Committee for Study for a Future Strategic Highway Research Program, Strategic Highway Research; Transportation Research Board Special Report 260; National Research Council: Washington, DC, USA, 2001.
  13. Jiménez-Mateos, J.M.; Quintero, L.C.; Rial, C. Characterization of petroleum bitumens and their fractions by thermogravimetric analysis and differential scanning calorimetry. Fuel 1996, 75, 1691–1700.
  14. Speight, J.C. The Chemistry and Technology of Petroleum, 3rd ed.; Marcel Dekker: New York, NY, USA, 1999.
  15. Ashoori, S.; Sharifi, M.; Masoumi, M.; Salehi, M.M. The Relationship between SARA Fractions and Crude Oil Stability. Egypt. J. Pet. 2017, 26, 209–213.
  16. Rostler, F.S. Fractional Composition: Analytical and Functional Significance; Hoiberg, A.J., Robert, E., Eds.; Krieger Publishing Company, Huntington: New York, NY, USA, 1979; Volume 2, pp. 151–222.
  17. Boutevin, B.; Pietrasanta, Y.; Robin, J.J. Bitumen-Polymer Blends for Coatings Applied to Roads and Public Constructions. Prog. Org. Coat. 1989, 17, 221–249.
  18. Polacco, G.; Stastna, J.; Biondi, D.; Zanzotto, L. Relation Between Polymer Architecture and Nonlinear Viscoelastic Behaviour of Modified Asphalts. Curr. Opin. Colloid Interface Sci. 2006, 11, 230–245.
  19. Walkering, C.P.; Vonk, W.C.; Whiteoak, C.D. Improved Asphalt Properties Using SBS modified Bitumens. Shell Bitum. Rev. 1992, 66, 9–11.
  20. Rodrigues, C.; Hanumanthgari, R. Polymer modified bitumens and other modified binders. In The Shell Bitumen Handbook, 6th ed.; Hunter, R.N., Self, A., Read, J., Eds.; ICE Publishing: London, UK, 2015; ISBN 978-0727758378.
  21. Valkering, C.P.; Vonk, W. Thermoplastic rubbers for the modification of bitumens: Improved elastic recovery for high deformation resistance of asphalt mixes. In Proceedings of the 15th Australian Road Research Board (ARRB) Conference, Darwin, Australia, 26–31 August 1999; pp. 1–19.
  22. Krutz, N.C.; Siddharthan, R.; Stroup-Gardiner, M. Investigation of rutting potential using static creep testing on polymer-modified asphalt concrete mixtures. Transp. Res. Rec. 1991, 1317, 100–118.
  23. Collins, J.H.; Bouldin, M.G.; Gelles, R.; Berker, A. Improved performance of paving asphalts by polymer modification (with discussion). In Proceedings of the Association of Asphalt Paving Technologists Technical Sessions, Seattle, DC, USA, 4–6 March 1991; pp. 43–79.
  24. Bouldin, M.G.; Collins, J.H.; Berker, A. Rheology and microstructure of polymer/asphalt blends. Rubber Chem. Technol. 1991, 64, 577–600.
  25. Wardlaw, K.R.; Shuler, S. (Eds.) Polymer Modified Asphalt Binders; ASTM: West Conshohocken, PA, USA, 1992; ISBN 0-8031-1413-3.
  26. Stock, A.F.; Arand, W. Low temperature cracking in polymer modified binders. In Proceedings of the Asphalt Paving Technology, Austin, TX, USA, 22–24 March 1993; pp. 23–53.
  27. Aglan, H. Polymeric additives and their role in asphaltic pavements. Part I: Effect of additive type on the fracture and fatigue behavior. J. Elastomers Plast. 1993, 25, 307–321.
  28. Bahia, H.U.; Anderson, D.A. Glass transition behavior and physical hardening of asphalt binders (with discussion). In Proceedings of the Asphalt Paving Technology, Austin, TX, USA, 22–24 March 1993; pp. 93–129.
  29. Elmore, W.E.; Thomas, W.K.; Mansour, S.; Bolzan, P. Long-Term Performance Evaluation of Polymer-Modified Asphalt Concrete Pavements; Report No.: FHWA-TX-94+1306-1F; Federal Highway Administration: Washington, DC, USA, 1993.
  30. Bonemazzi, F.; Braga, V.; Corrieri, R.; Giavarini, C. Characteristics of polymers and polymer-modified binders. Transp. Res. Rec. 1996, 1535, 36–47.
  31. Brulè, B. Polymer-modified asphalt cements used in the road construction industry: Basic principles. Transp. Res. Rec. 1996, 1535, 48–53.
  32. Adedeji, A.; Grünfelder, T.; Bates, F.S.; Macosko, C.W.; Stroup-Gardiner, M.; Newcomb, D.E. Asphalt modified by SBS triblock copolymer: Structures and properties. Polym. Eng. Sci. 1996, 36, 1707–1723.
  33. Shin, E.E.; Bhurke, A.; Edward, S.; Rozeveld, S.; Drzal, L.T. Microstructure, morphology, and failure modes of polymer-modified asphalts. Transp. Res. Rec. 1996, 1535, 61–73.
  34. Loeber, L.; Durand, A.; Muller, G.; Morel, J.; Sutton, O.; Bargiacchi, M. New investigations on the mechanism of polymer–bitumen interaction and their practical application for binder formulation. In Proceedings of the 1st Eurasphalt & Eurobitume Congress, Congress Paper No. 5115, Strasbourg, France, 7–10 May 1996.
  35. Gahvari, F. Effects of thermoplastic block copolymers on rheology of asphalt. J. Mater. Civ. Eng. 1997, 9, 111–116.
  36. Standard Specification for Asphalt-Rubber Binder, D 6114–97; ASTM: West Conshohocken, PA, USA, 2002.
  37. Galooyak, S.S.; Dabir, B.; Nazarbeygi, A.E.; Moeini, A. Rheological Properties and Storage Stability of Bitumen/SBS/Montmorillonite Composites. Constr. Build. Mater. 2010, 24, 300–307.
  38. Studebaker, M.L. Effect of Curing Systems on Selected Physical Properties of Natural Rubber Vulcanizates. Rubber Chem. Technol. 1966, 39, 1359–1381.
  39. Giavarini, C.; De Filippis, P.; Santarelli, M.L.; Scarsella, M. Production of stable polypropylene-modified bitumens. Fuel 1996, 75, 681–686.
  40. Rojo, E.; Fernàndez, M.; Peña, J.J.; Peña, B. Rheological aspects of blends of metallocene-catalysed atactic polypropylenes with bitumen. Polym. Eng. Sci. 2004, 44, 1792–1799.
  41. González, O.; Muñoz, M.E.; Santamaría, A. Bitumen/polyethylene blends: Using m-LLDPEs to improve stability and viscoelastic properties. Rheol. Acta 2006, 45, 603–610.
  42. Wen, G.; Zhang, Y.; Zhang, Y.; Fan, Y. Rheological Characterization of Storage-Stable SBS-Modified Asphalts. Polym. Test. 2002, 21, 295–302.
  43. Henderson, G. Bituminous Binders and Process of Making Same from Coal-Tar Pitch. U.S. Patent 1264932, 30 July 1917.
  44. Gagle, D.W.; Draper, H.L. High Ductility Asphalt. U.S. Patent 4130516, 12 April 1976.
  45. Wen, G.; Zhang, Y.; Zhang, Y.; Sun, K.; Chen, Z. Vulcanization characteristics of asphalt/SBS blends in the presence of sulphur. J. Appl. Polym. Sci. 2001, 82, 989–996.
  46. Wen, G.; Zhang, Y.; Zhang, Y.; Sun, K. Improved properties of SBS modified asphalt with dynamic vulcanization. Polym. Eng. Sci. 2002, 42, 1070–1081.
  47. Chen, J.S.; Huang, C.C. Fundamental characterization of SBS-modified asphalt mixed with sulphur. J. Appl. Polym. Sci. 2006, 103, 2817–2825.
  48. Zhang, F.; Yu, J.; Wu, S. Effect of ageing on rheological properties of storage-stable SBS/sulphur-modified asphalts. J. Hazard Mater. 2010, 182, 507–517.
  49. Zhang, F.; Yu, J.; Han, J. Effects of thermal oxidative ageing on dynamic viscosity, TG/DTG, DTA and FTIR of SBS-and SBS/sulphur-modified asphalts. Constr. Build. Mater. 2011, 25, 129–137.
  50. Masson, J.-F.; Gagné, M. Polyphosphoric Acid (PPA)-Modified Bitumen: Disruption of the Asphaltenes Network Based on the Reaction of Non-basic Nitrogen with PPA. Energy Fuels 2008, 22, 3402–3406.
  51. Miknis, F.P.; Thomas, K.P. NMR Analysis of Polyphosphoric Acid-modified Bitumens. Road Mater. Pavement Des. 2008, 9, 59–72.
  52. Jaroszek, H. Polyphosphoric acid (PPA) in road asphalts modification. CHEMIK 2012, 66, 1340–1345.
  53. García-Morales, M. Dodecylbenzenesulfonic Acid as a Bitumen Modifier: A Novel Approach to Enhance Rheological Properties of Bitumen. Energy Fuels 2017, 31, 5003–5010.
  54. Herrington, P.R.; Wu, Y.; Forbes, M.C. Rheological modification of bitumen with maleic anhydride and dicarboxylic acids. Fuel 1999, 78, 101–110.
  55. Kang, Y.; Wang, F.; Chen, Z. Reaction of asphalt and maleic anhydride: Kinetics and mechanism. Chem. Eng. J. 2010, 164, 230–237.
  56. Cong, P.; Chen, S.; Chen, H. Preparation and properties of bitumen modified with the maleic anhydride grafted styrene-butadiene-styrene triblock copolymer. Polym. Eng. Sci. 2011, 51, 1273–1279.
  57. Marzocchi, A.; Roberts, M.G.; Bolen, C.E. Asphalt Compositions Modified with Organo-Silane Compounds. U.S. Patent US4292371A, 24 March 1980.
  58. Peng, C.; Chen, P.; You, Z.; Lv, S.; Zhang, R.; Xu, F.; Zhang, H.; Chen, H. Effect of silane coupling agent on improving the adhesive properties between asphalt binder and aggregates. Constr. Build. Mater. 2018, 169, 591–600.
  59. Cuadri, A.A.; Partal, P.; Navarro, F.J.; García-Morales, M.; Gallegos, C. Bitumen chemical modification by thiourea dioxide. Fuel 2011, 90, 2294–2300.
  60. Ouyang, C.; Wang, S.; Zhang, Y.; Zhang, Y. Preparation and properties of styrene–butadiene–styrene copolymer/kaolinite clay compound and asphalt modified with the compound. Polym. Degrad. Stab. 2005, 87, 309–317.
  61. Ouyang, C.; Wang, S.; Zhang, Y.; Zhang, Y. Thermo-rheological properties and storage stability of SEBS/kaolinite clay compound modified asphalts. Eur. Polym. J. 2006, 42, 446–457.
  62. Ouyang, C.; Wang, S.; Zhang, Y.; Zhang, Y. Low-density polyethylene/silica compound modified asphalts with high-temperature storage stability. J. Appl. Polym. Sci. 2006, 101, 472–479.
  63. Yu, J.; Wang, L.; Zeng, X.; Wu, S.; Li, B. Effect of montmorillonite on properties of styrene–butadiene–styrene copolymer modified bitumen. Polym. Eng. Sci. 2007, 47, 1289–1295.
  64. Polacco, G.; Kříž, P.; Filippi, S.; Stastna, J.; Biondi, D.; Zanzotto, L. Rheological properties of asphalt/SBS/clay blends. Eur. Polym. J. 2008, 44, 3512–3521.
  65. Zhang, B.; Xi, M.; Zhang, D.; Zhang, H.; Zhang, B. The effect of styrene-butadiene-rubber/montmorillonite modification on the characteristics and properties of asphalt. Constr. Build. Mater. 2009, 23, 3112–3117.
  66. Golestani, B.; Nejad, F.M.; Galooyak, S.S. Performance evaluation of linear and nonlinear nanocomposite modified asphalts. Constr. Build. Mater. 2012, 35, 197–203.
  67. Jasso, M.; Bakos, D.; MacLeod, D.; Zanzotto, L. Preparation and properties of conventional asphalt modified by physical mixtures of linear SBS and montmorillonite clay. Constr. Build. Mater. 2013, 38, 759–765.
  68. Zhang, H.; Yu, J.; Wang, H.; Xue, L. Investigation of microstructures and ultraviolet aging properties of organo-montmorillonite/SBS modified bitumen. Mater. Chem. Phys. 2011, 129, 769–776.
  69. Zanzotto, L.; Stastna, J.; Vacin, O. Thermomechanical properties of several polymer modified asphalts. Appl. Rheol. 2000, 10, 134–144.
  70. Hesp, S.; Hoare, T.R.; Roy, S.D. Low-temperature fracture in reactive ethylene-terpolymer-modified asphalt binders. Int. J. Pavement Eng. 2002, 3, 153–159.
  71. Polacco, G.; Stastna, J.; Biondi, D.; Antonelli, F.; Vlachovicova, Z.; Zanzotto, L. Rheology of asphalts modified with glycidylmethacrylate functionalized polymers. J. Colloid Interface Sci. 2004, 280, 366–373.
  72. Yeh, P.H.; Nien, Y.-H.; Chen, J.-H.; Chen, W.-C.; Chen, J.-S. Thermal and rheological properties of maleated polypropylene modified asphalt. Polym. Eng. Sci. 2005, 45, 1152–1158.
  73. Fu, H.; Xie, L.; Dou, D.; Li, L.; Yu, M.; Yao, S. Storage stability and compatibility of asphalt binder modified by SBS graft copolymer. Constr. Build. Mater. 2007, 21, 1528–1533.
  74. Wang, Q.; Liao, M.; Wang, Y.; Ren, Y. Characterization of end functionalized styrene butadiene–styrene copolymers and their application in modified asphalt. J. Appl. Polym. Sci. 2007, 103, 8–16.
  75. Navarro, F.J.; Partal, P.; García-Morales, M.; Martinez-Boza, F.J.; Gallegos, C. Bitumen modification with a low-molecular-weight reactive isocyanate-terminated polymer. Fuel 2007, 86, 2291–2299.
  76. Li, J.; Zhang, Y.; Zhang, Y. The research of GMA-g-LDPE modified Qinhuangdao bitumen. Constr. Build. Mater. 2008, 22, 1067–1073.
  77. Martin-Alfonso, M.J.; Partal, P.; Navarro, F.J.; García-Morales, M.; Gallegos, C. Use of an MDI functionalized reactive polymer for the manufacture of modified bitumen with enhanced properties for roofing applications. Eur. Polym. J. 2008, 44, 1451–1461.
  78. Martin-Alfonso, M.J.; Partal, P.; Navarro, F.J.; García-Morales, M.; Gallegos, C. Role of water in the development of new isocyanate-based bituminous products. Ind. Eng. Chem. Res. 2008, 47, 6933–6940.
  79. Martin-Alfonso, M.J.; Partal, P.; Navarro, F.J.; García-Morales, M.; Bordado, J.C.M.; Diogo, A.C. Effect of processing temperature on the bitumen/ MDI–PEG reactivity. Fuel Process. Technol. 2009, 90, 525–530.
  80. Navarro, F.J.; Partal, P.; García-Morales, M.; Martín-Alfonso, M.J.; Martínez-Boza, F.; Gallegos, C.; Bordado, J.C.M.; Diogo, A.C. Bitumen modification with reactive and non-reactive (virgin and recycled) polymers: A comparative analysis. J. Ind. Eng. Chem. 2009, 15, 458–464.
  81. Carrera, V.; Partal, P.; García-Morales, M.; Gallegos, C.; Páez, A. Influence of bitumen colloidal nature on the design of isocyanate-based bituminous products with enhanced rheological properties. Ind. Eng. Chem. Res. 2009, 48, 8464–8470.
  82. Carrera, V.; Garcia-Morales, M.; Partal, P.; Gallegos, C. Novel bitumen/isocyanate-based reactive polymer formulations for the paving industry. Rheol. Acta 2010, 49, 563–572.
  83. Shivokhin, M.; Garcia-Morales, M.; Partal, P.; Cuadri, A.A. Rheological behaviour of polymer-modified bituminous mastics: A comparative analysis between physical and chemical modification. Constr. Build. Mater. 2012, 27, 234–240.
  84. Rossi, D.; Filippi, S.; Merusi, F.; Giuliani, F.; Polacco, G. Internal Structure of Bitumen/Polymer/Wax Ternary Mixtures for Warm Mix Asphalt. J. Appl. Polym. Sci. 2013, 129, 3341–3354.
  85. Edwards, Y.; Redelius, P. Rheological Effects of Waxes in Bitumen. Energy Fuels 2003, 17, 511–520.
  86. Warth, A.B. The Chemistry and Technology of Waxes; Reinhold: Waldwick, NJ, USA, 1956.
  87. Thanh, N.X.; Hsieh, M.; Philip, R.P. Waxes and Asphaltenes in Crude Oils. Org. Geochem. 1999, 30, 119–132.
  88. Edwards, Y.; Isacsson, U. Wax in Bitumen, Part 1-Classifications and General Aspects. Road Mater. Pavement Des. 2005, 6, 281–309.
  89. Edwards, Y.; Isacsson, U. Wax in Bitumen, Part 2-Characterization and Effects. Road Mater. Pavement Des. 2005, 6, 439–468.
  90. Lu, X.; Kalman, B.; Redelius, P. A New Test Method for Determination of Wax Content in Crude Oils, Residues and Bitumen. Fuel 2008, 87, 1543–1551.
  91. Lu, X.; Langton, M.; Olofsson, P.; Redelius, P. Wax Morphology in Bitumen. J. Mater. Sci. 2005, 40, 1893–1900.
  92. Michon, L.C.; Netzel, D.A.T.; Turner, F.; Martin, D.; Planche, J.P. A 13C NMR and DSC Study of the Amorphous and Crystalline Phases in Asphalts. Energy Fuels 1999, 13, 603–610.
  93. Lu, X.; Redelius, P. Compositional and Structural Characterization of Waxes Isolated from Bitumens. Energy Fuels 2006, 20, 653–660.
  94. Lu, X.; Redelius, P. Effect of Bitumen Wax on Asphalt Mixture Performance. Constr. Build. Mater. 2007, 21, 1961–1970.
  95. Lee, H.; Wong, W. Effect of wax on basic and rheological properties of bitumen with similar Penetration-grades. Constr. Build Mater. 2009, 23, 507–514.
  96. Wong, W.; Li, G. Analysis of the effect of wax content on bitumen under performance grade classification. Constr. Build. Mater. 2009, 23, 2504–2510.
  97. Giuliani, F.; Merusi, F. Flow Characteristics and Viscosity Functions in Asphalt Binders Modified by Wax. Int. J. Pavement Res. Technol. 2009, 2, 51–60.
  98. Merusi, F.; Caruso, A.; Roncella, R.; Giuliani, F. Moisture Susceptibility and Stripping Resistance of Asphalt Mixture Modified with Different Synthetic Waxes. Transp. Res. Rec. 2010, 2180, 110–120.
  99. Merusi, F.; Giuliani, F. Rheological Characterization of Wax-Modified Asphalt Binders at High Service Temperatures. Mater. Struct. 2011, 44, 1809–1820.
  100. Edwards, Y.; Tasdemir, Y.; Butt, A. An Energy Saving and Environmental Friendly Wax Concept for Polymer Modified Mastic Asphalt. Mater. Struct. 2010, 43, 123–131.
  101. Kim, H.; Lee, S.J.; Amirkhasian, S.N. Effects of Warm Mix Asphalts Additives on Performance Properties of Polymer Modified Asphalt Binders. Can. J. Civ. Eng. 2010, 37, 17–24.
  102. Kim, H.; Lee, S.J.; Amirkhasian, S.N. Performance Evaluation of Recycled PMA Binders Containing Warm Mix Asphalt Additives. J. Test. Eval. 2011, 39, 728–734.
  103. Akisetty, C.K.; Lee, S.J.; Amirkhanian, S.N. Laboratory Investigation of the Influence of Warm Asphalt Additives on Long-Term Performance Properties of CRM Binders. Int. J. Pavement Eng. 2011, 11, 153–160.
  104. Gonzalez, V.; Martinez-Boza, F.J.; Navarro, F.J.; Gallegos, C.; Perez-Lepe, A.; Paez, A. Thermomechanical Properties of Bitumen Modified with Crumb Rubber and Polymeric Additives. Fuel Process. Technol. 2010, 91, 1033–1039.
  105. Akisetty, C.K.; Gandhi, T.; Lee, S.J.; Amirkhanian, S.N. Analysis of Rheological Properties of Rubberized Binders Containing Warm Asphalt Additives. Can. J. Civ. Eng. 2010, 37, 763–771.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
This entry is offline, you can click here to edit this entry!
ScholarVision Creations
Feedback