NL2025746B1

NL2025746B1 - Rejuvenator for Recycling of polymer Modified Asphalt Concrete Pavement

Info

Publication number: NL2025746B1
Application number: NL2025746A
Authority: NL
Inventors: Lin Peng; Maria Johanna Grada Erkens Sandra; Liu Xueyan; Apostolidis Panagiotis
Original assignee: Univ Delft Tech
Priority date: 2020-06-03
Filing date: 2020-06-03
Publication date: 2022-03-04
Also published as: WO2021246871A1

Abstract

The present invention is in the field of chemical composition referred to as a rejuvenator for recycling of polymer modified asphalt concrete pavement, to a reclaimed polymeric network comprising said rejuvenator, to asphalt comprising reclaimed polymer modified bitumen, to reclaimed asphalt shingles comprising the polymer modified bitumen, to constructions comprising the reclaimed polymeric network, and to a method of applying said rejuvenator.

Description

P100422NL00 1 Rejuvenator for Recycling of polymer Modified Asphalt Concrete Pavement

FIELD OF THE INVENTION The present invention is in the field of chemical composition referred to as a rejuvenator for recycling of polymer modified asphalt concrete pavement, to a reclaimed polymeric network comprising said rejuvenator, to asphalt comprising reclaimed polymer modified bitumen, to reclaimed asphalt shingles comprising the polymer modified bitumen, to constructions comprising the reclaimed polymeric network, and to a method of applying said rejuvenator.

BACKGROUND OF THE INVENTION Asphalt, also known as bitumen is a sticky, black, and highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product. Asphalt, as well as polymer modified bitumen (PMB) is often used in road structures. Over time the asphalt/PMB deteriorates and often needs to be replaced as a consequence.

Nowadays, the use of milled or post-processed old asphalt, named reclaimed asphalt pavement (RAP), in newly produced asphaltic materials in plants is a common practice in many countries, offering economic and environmental benefits, such as reduction of material cost, conservation of landfill space and lower demand on natural resources. At the same time, polymer-modified bitumen (PMB) binders have been extensively used worldwide as well for premium (highly trafficked) asphalt pavements. Nevertheless, a large amount of RAP including PMB binders is produced every year. Together with the continuously increasing demand to incorporate PMB RAP in the asphalt production, the use of rejuvenators for RAP materials modified with polymers is becoming important. High temperatures are used through the recycling process in asphalt plants to improve the activation of aged PMBs and in combination with the complicated mechanism of PMBs aging (i.e., bitumen oxidation and polymer degradation}. Therefore

P100422NL00 2 special attention is given to developing compatible rejuvenators with the aged PMBs.

Rejuvenators are chemical compositions or compounds designed to restore properties of aged binders to a state at which aged materials could be incorporated in the newly produced asphalt pavements. Examples are organic rejuvenators which can be applied in lower dosages than other. However, these organic rejuvenators are found not suitable to rejuvenate aged PMB. For instance, during shearing and stirring in the production process of PMB binders, styrene-butadiene-styrene (SBS) polymer absorbs the aromatic compounds from the bitumen and polymer swelling occurs. Thus, not suited compounds may lead to agglomeration, segregation and phase separation of the polymeric network in bitumen.

To recover aged binders to their original state, it may be necessary to add a certain amount of polymer modifiers into the rejuvenators. Apart from the SBS polymer that may show improved compatibility with the aged PMB binders, rubber modifiers are also promising as they can improve the low-temperature properties. Especially, the addition of treated rubber modifiers decreases the viscosity of rejuvenators when the terminal blend (TB) modification is followed.

The present invention therefore relates to rejuvenator and applications thereof, which solves one or more of the above problems and drawbacks of the prior art, providing reliable results, without jeopardizing functionality and advantages.

SUMMARY OF THE INVENTION It is an object of the invention to overcome one or more limitations of the prior art. In a first aspect the present invention relates to a rejuvenator for a polymeric network comprising 1-25 wt.% of at least one substantially intact polymer, preferably 3-20 wt.%, more preferably 4-15 wt.%, such as 5-11 wt.%, 15-50 wt.% of at least one aromatic oil, such as a synthetic or natural aromatic oil, preferably 20-45 wt.%, more preferably 25-40 wt.%, such as 30-35 wt.%,

P100422NL00 3

0.3-10 wt.% of at least one additives, wherein the at least one additive is preferably selected from terpenes, preferably 0.5-5 wt.%, more preferably 1-4 wt.%, such as 2-3 wt.%, 30-75 wt.% of at least one saturated acidic oil, preferably 35-68 wt.%, more preferably 40-63 wt.%, such as 47-55 wt.%, 0.4-10 wt.% of at least one resin for activating (i.e. improving compatibility between substantially intact polymer and aged polymer in the) polymeric network, preferably 0.5-5 wt.%, more preferably 1-4 wt.%, such as 2-3 wt.%, wherein all weight percentages are based on the total weight of the rejuvenator. The rejuvenator may be considered as a type chemical agent to restore properties of polymeric network and to compensate for the loss of chemical composition during aging. The fresh or undamaged polymer, for example crumb rubber, might have been used for a long time, however the polymer network inside is still healthy compared with the polymer network in polymer modified bitumen. The present resin is for activating aged polymer and/or improving the compatibility between polymeric network and bitumen. In a study, a set of rejuvenators was produced and their influence on performance-based properties of PMB binders was investigated. The polymer modified bitumen (PMB) may be considered as a series of special bitumen which contains a polymer, such as SBS. The polymeric network is then a polymer structure in polymer modified bitumen, which is formed by the SBS polymer and can improve the properties of PMB. A set of rheological tests were conducted at low, medium and high temperatures and a ranking method is proposed to evaluate the efficiency of these rejuvenators. A series of rejuvenators were used for the rejuvenator dosage determination as well. Finally, Environmental Scanning Electron Microscopy (E-SEM) was used to visualize the influence of rejuvenators on the micro-structure of the rejuvenated binder. The present rejuvenator was designed on the base of a deep understanding of the aging mechanism of polymer modified bitumen and bitumen colloidal stability theory. The added fresh, substantially intact, polymer component in the invented rejuvenator can assist the

P100422NL00 4 reconstruction of the polymeric network and repair the degraded polymers in the aged polymer-modified bitumen. The schematic drawing of the principle of polymer network rebuilt with different types of rejuvenators can be seen in figure 1. An aromatic oil selected to supplement the lost component during aging which is found to enhance the colloidal structure stability of the rejuvenated binder. The proportion of different compositions in the rejuvenator was determined according to bitumen colloidal stability theory and optimized with plenty of tentative tests. Furthermore, several specific additives were added in the invented rejuvenator to dissolve the conglomeration of asphaltene and improve its diffusion into aged bitumen. Compared with several commercial available rejuvenators, the application of the present rejuvenator is more effective in terms of improving the viscoelastic response, cracking resistance, rutting resistance and low-temperature performance of the aged polymer modified bitumen, and the rejuvenation effect is more stable in multi-circle recycling practices.

Regarding the rejuvenation mechanism study by using the Differential Scanning Calorimetry (DSC) and Environmental Scanning Electron Microscopy (ESEM) tests, it was found that the present rejuvenator can build up the micro reinforced polymer network inside the rejuvenated bitumen and hence improve the compatibility between fresh and aged polymer modified binder and mechanical performance of the modified RAP. Experimental study of the invented rejuvenator for high-quality recycling of polymer modified asphalt are found.

The present invention is equally applicable to other polymeric networks.

In a second aspect the present invention relates to a reclaimed polymeric network, such as reclaimed modified bitumen, comprising 1-20 wt.% of at least one rejuvenator according to the invention, such as 2-15 wt.%, and rejuvenated aged polymer modified bitumen, wherein the polymer in the modified bitumen is preferably selected from block polymers, such as styrene-butadiene-styrene (SBS)

P100422NL00 polymer, natural or synthetic latex, such as polychloroprene latex, and reclaimed rubber. In a third aspect the present invention relates to an asphalt product comprising reclaimed polymer modified 5 bitumen according to the invention, such as asphalt, asphalt shingles, and asphalt waterproofing, or a rejuvenator according to the invention.

13. Construction comprising asphalt according to any of embodiments 11-12, wherein the construction is selected from a multilayer civil engineering system, such as an asphalt concrete surfacing layer on orthotropic steel deck bridge, a foundation, a wall, a basement, a building, and combinations thereof, and/or wherein the construction comprises at least one of a waterproofing, a top laver, and a deck layer.

In a fourth aspect the present invention relates to a method of applying a rejuvenator for a polymeric network according to the invention, comprising mixing the rejuvenator and aged polymer modified bitumen, pre-heating the mixture to a temperature of 350-433 K(77-160 °C) during a pre-heating period of time, heating the mixture to a temperature of 430-473 K(157-200 °C) during a heating period of time, maintaining said temperature for at least 1 minute, cooling the mixture, and applying the mixture, such as to a road.

In a fifth aspect the present invention relates to a use of a rejuvenator for a polymeric network according to the invention for healing the polymeric network, for improving viscoelasticity, enhancing colloidal stability, dissolving asphaltene, improving durability, improving anti-cracking, improving aging resistance, improving compatibility, improving relaxation, increasing maximum stress, or a combination thereof.

Advantages of the present description are detailed throughout the description.

DETAILED DESCRIPTION OF THE INVENTION In an exemplary embodiment of the present rejuvenator the polymeric network is selected from polymer modified

P100422NL00 6 bitumen, modified asphalt comprising a polymer, such as modified asphalt concrete.

In an exemplary embodiment of the present rejuvenator the polymer is selected from co-polymers, preferably comprising a flexible domain, such as from linear copolymers, such as block copolymers, alternating copolymers, periodic copolymers, statistical copolymers, stereo-block copolymers, and gradient copolymers, branched copolymers, and graft copolymers, preferably from ethylene- butyl-acrylate (EBA), styrene-butadiene-styrene (SBS), and natural or synthetic rubber.

In an exemplary embodiment of the present rejuvenator the aromatic oil comprising at least one aromatic moiety has an aromatic content (i.e. molecules with at least one aromatic ring) of > 25%, preferably >30%, more preferably > 40%, even more preferably >50%, such as > 654.

In an exemplary embodiment of the present rejuvenator the aromatic oil is selected from rubber processing oil, 1- 3 vacuum side-stream of crude oil, reduced crude oil, synthetic or natural aromatic oil, mineral oil, and combinations thereof.

In an exemplary embodiment of the present rejuvenator the aromatic oil is adapted to dissolve asphaltene, wherein the aromatic oil may be provided as a liquid comprising 10- 65 wt. 3 solvent.

In an exemplary embodiment of the present rejuvenator the at least one additive is selected from organic solvents, such as asphaltene solvents, such as monoterpenes (CioHis), preferably cyclic- or bicyclic monoterpenes, such as geraniol, terpineol, limonene (CicHie; CAS 139-86-3/5989-27- 5/5989-54-8), myrcene, linalool, and pinene (CigHis; CAS 80- 56-8/7785-70-8/7785-26-4/2437-95-8/18172-67-3), sesquiterpenes (CisHzy), such as humulene (CAS 6753-98-06), farnesenes, and farnesol, diterpenes (C:8H3:)}, such as cafestol, kahweol, cembrene, and taxadiene, triterpines (C39Ha4s) , such as squalene.

In an exemplary embodiment of the present rejuvenator the at least one saturated acidic oil, preferably an oil

P100422NL00 7 with more than 16 carbons and at least one carboxylic acid, such as more than 20 carbons and at least one carboxylic acid, such as rapeseed oil.

In an exemplary embodiment of the present rejuvenator the at least one resin is selected from hydrocarbon resins, such as C4-C1i2 resins, preferably Cs-Ci9 resins, more preferably Cs-Cs resins, most preferably Ce-Cs resins.

Cs aliphatic, Cs aromatic, and DCPD cycloaliphatic resins are most preferred.

Hydrocarbon resins are amorphous thermoplastic polymers produced by polymerization of unsaturated hydrocarbons.

The feedstock are various by- products of naphtha crackers.

These resins have typically a low molecular weight ranging from about 400 to 5000 g/mol.

The three main types are Cs aliphatic, Cs aromatic, and DCPD cycloaliphatic resins.

They are sometimes hydrogenated to reduce discoloration and to improve their heat and UV stability.

Aromatic hydrocarbon resins (Cs Resins) can be made from Cs aromatic hydrocarbons.

Their composition depends on the hydrocarbon feedstock (coal tar, crude oil). The most important base monomers are indene, methyindenes, dicyclopentadiene, styrene, alpha-methyl styrene and various vinyl toluenes.

These resins are available in a wide range of softening points.

Compared to Cs resins, they have a much higher melt viscosity, are of darker colour (dark yellow to brown) and have higher softening point ranging from about 100 to 150°C.

Cs resins are very versatile resins that are compatible with many polymers.

Hydrogenated C:/Ce resins and resin blends are also commercially available.

These resins are often colourless and have improved heat and colour stability.

Aliphatic hydrocarbon resins (C5 Resins) are made from C5 piperylene and its derivatives.

The most important ones are cis/trans 1,3-pentadienes, 2-methyl-2-butene, cyclopentene, cyclopentadiene, and dicyclopentadiene (see below). These monomers are polymerized to oligomeric resins with low to high softening point using Lewis acid catalysts.

Cb resins are aliphatic in nature and are, therefore, fully compatible with natural rubber, most olefins (LDPE) and many synthetic

P100422NL00 8 elastomers of low polarity. They are available in a wide range of molecular weights (MW) and softening points (solid grades 85 - 115°C and liquid grades 5 - 10°C) and provide outstanding tack. They also have a light yellow to light brown colour and possess excellent heat stability.

In an exemplary embodiment the present asphalt further comprises one or more of particles, coarse aggregate, filler, extender, fibres, oxidants, anti-oxidants, plastics, anti-stripping agents, and waste material.

The invention will hereafter be further elucidated through the following examples which are exemplary and explanatory of nature and are not intended to be considered limiting of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present embodiments.

SUMMARY OF THE FIGURES Figs. 1-10 show experimental details.

DETAILED DESCRIPTION OF FIGURES FIGURE 1 Scheme of polymer network of SBS modified bitumen with different rejuvenators. The rubbery supporting network is mainly derived from physical and chemical crosslinking (see FIGURE 1 (a)). The physical crosslinking network is constructed by the polystyrene domain connecting with flexible polybutadiene, which improves elastic response in the high frequency region and brings about higher viscosity compared with base bitumen in the low frequency region. The chemical crosslinking network formed with the help of elemental sulphur, which can form the bonding between sulphur and the polybutadiene chains. As illustrated in FIGURE 1 (bk), due to the aging sensitivity of polybutadiene, the flexible and elastic connection parts of the crosslinking network break down, which led to a significant down gradation of rheological properties.

The addition of a rejuvenator containing polymer is a feasible way to compensate for the degradation of the polymer and reconstruct the network. Although the commercial bio-based

P100422NL00 9 rejuvenators can significantly decrease the viscosity, it can only dilute and change the distribution of the degraded polymer network, rather than reconstruct the polymer network (see FIGURE 1 (c)). For reconstruction, proper type and content of polymer modifier can be pre-treated to absorb the aromatic and saturate component during fabrication to enhance the quick fusion of rejuvenator and aged binder.

After mixing with the aged binder in the RAP at relatively high temperature (135~170 °C), although chemical crosslinking will not be rebuilt without elemental sulphur, the physical crosslinking is possible to restore after cooling to ambient temperature (FIGURE 1 (d)). And the reconstruction of the polymer network will help to recover the viscoelastic property of the rejuvenated binder.

However, it is worth noting that if the polymer selected is too stiff or the polymer content is too high, the degree of crosslinking may become too high, which may lead to a significant increase of stiffness and viscosity (FIGURE 1 (e)). Thus, the key of rejuvenator containing polymer is to find a balance point between decreasing viscosity and recovering polymer network.

Master-curves of complex modulus (figure 2) and phase angle of rejuvenated binders (figure 3). Figure 4 and 5 Anti-cracking analysis of rejuvenated binders.

Figure 6 Master-curves of complex modulus and figure 7 of phase angle for the rejuvenated binders after a second aging phase (RTFOT+80 hours PAV at 100°C). Figure 8 Radar chart (a) and rank value (b) of the different rejuvenated binders Figure 9 Maximum stress of rejuvenated bitumen with different rejuvenator dosage Figure 10 SEM images of studied binders: (a) original PMB; and aged (b) PMB; (c) PMB +10% Rej B; (d) PMB +20% Rej B; (e) PMB +304 Rej B; (f) PMB +30% Rej F; {g) PMB +304 Rej E; (h) PMB +10% Rej B+50% fresh PMB; (i) PMB +104 Rej E+50%

P100422NL00 10 fresh PMB.

Examples Materials and description More than 60 types of rejuvenators with different compositions and ratios were prepared in the lab.

Four novel rejuvenators are presented here for comparison.

Apart from the 4 lab-produced rejuvenators (Rej A to Rej D}), rejuvenators E (designed for PMB binders) and F (designed for base binders) were commercially available products (see Table 1). The binder was a commercial SBS-PMB with a softening point of 65.7°C and a penetration of 30 (0.1-mm). To assess the restoring effect of various rejuvenators on this binder after two rejuvenation circles, a special material preparation method was followed.

Firstly, the binder was subjected to short-term aging using Rolling Thin Film Oven Test (RTFOT) (EN 12607:2002) and long-term aging with a Pressure Aging Vessel (PAV) (EN14769:2006)} for 80 hours, since a previous study has shown that this aging condition is similar to the aging of a porous surface layer after 10 years of service life.

Afterward, the aged binder (AB) was heated at 170 °C and mixed with rejuvenators (10% by weight of AB). In the last step, the rejuvenated bitumen (reB, see Table 1) was again subjected to RTFOT aging and 80 hours PAV to simulate the second rejuvenation cycle.

Table 1 Description of rejuvenators and rejuvenated bitumen binder.

Name Description Rejuvenators Rej A EBA-based liquid incl. saturated aromatic component Rej B SBS-based liquid incl. saturated aromatic component Rej C Rubber-based liquid incl. saturated aromatic component Rej D SBS/Rubber-based liquid incl. saturated aromatic component Rej E Bio-based commercial rejuvenator for recycling of polymer modified bitumen

P100422NL00 11 Rej F Compound commercial rejuvenator for recycling of base bitumen Compositions z Aromatic Oil Polymer Resin Rapeseed oil limonene pinene A 30-40 4-11% 1-3% 42-63% 1-22 1-2% B 25-35 3-10% 2-4% 47-68% 1-23 1-24 C 25-30 15-20% 2-44 42-56% 1-2% 1-2% D 23-29 15-208 2-4% 38-55% 1-2% 1-2% Rejuvenated Binder OB Original SBS polymer modified bitumen AB SBS polymer modified bitumen after ageing reB-A AB + 10% wt.

Rej A reB-B AB + 10% wt.

Rej B reB-C AB + 10% wt.

Rej C reB-D AB + 103 wt.

Rej D reB-E AB + 10% wt.

Rej E reB-F AB + 103 wt.

Rej F Note: E and F are commercially available products, With 10% of commercial rejuvenator E, the aged PMB binder recovered to PG-70 Complex modulus and phase angle master-curves The master-curves of the complex modulus for the rejuvenated binders are presented in Figures 2-3. It can be seen that the aging led to an upward shift of the complex modulus, and the modulus increase at low frequencies is more obvious than at high frequencies.

The rejuvenation of the aged binders led to a downward parallel shift of master-curves demonstrating the significant decrease of complex modulus both at high and low frequencies.

The complex modulus of the rejuvenated binders did not get as low as the complex modulus of the original binder at high temperatures, but the modulus at the low temperature of the rejuvenated binders was relatively lower compared with the viscoelastic characteristics of the original binder.

From the complex modulus master-curves, reB-B and reB-E had the lowest modulus at low and high frequencies, respectively.

As given in Table 1 and Figure 2-3, reB-B was

P100422NL00 12 treated with Rej-B, which was an SBS-based rejuvenator including aromatic and saturate compounds.

It is found that when the asphaltene content increases during aging, reduction of the aromatic content occurs together with significant degradation of the SBS polymer in SBS-PMB binders . The addition of Rej-B complemented the lost components of the PMB during aging, leading to a significant rejuvenation effect.

In the case of reB-E, the mechanism of rejuvenation is totally different compared to Rej-B.

The saturate content in bitumen changes little during aging.

Hence, the Rej-E plays the so-called “dilution” role by increasing the saturate compounds.

The “dilution” effect can reduce the complex modulus effectively, however, it cannot improve the phase angle of the aged binders to the same level.

With respect to reB-A, reB-C and reB-D, the rejuvenation effect was not obvious and thus the corresponding Rej-A, Rej-C and Rej-D rejuvenators which were based on EBA, rubber and rubber/SBS, respectively, cannot reduce the modulus effectively both at low and high frequencies.

The SBS-based rejuvenator is suitable for upgrading the aged SBS-PMBs.

There is a plateau zone for the phase angle for OB, which is an indicator of the crosslinking network of the SBS polymer.

However, the phase angle plateau zone disappeared and the phase angle reduced significantly after aging, indicating a serious deterioration of the SBS polymeric network in bitumen.

After rejuvenation, reB-B and reB-F show an increase of the phase angle, indicating that the rejuvenators Rej-B and Rej-F improved the viscous response of the aged binders.

The viscous response of binders will assist in minimizing the risk of cracking at medium and low temperatures.

The aromatics in both rejuvenators compensate for the loss of aromatics fraction of PMB during aging.

Meanwhile, the Rej-B shows a higher rejuvenation efficiency than Rej-F, since the SBS polymer plays a significant role in increasing the viscous response of binders.

In terms of reBE, its phase angle is consistent at low frequencies and increases slightly in the high-frequency region,

P100422NL00 13 illustrating that the “dilution” effect cannot recover the phase angle effectively.

Regarding reB-A, C and D, the Rej-C and D did not demonstrate much increase of the phase angle and Rej-A even caused a significant decrease of the phase angle at low frequency.

As shown in Figures 4-5, all the curves of aged binders and rejuvenated binders moved towards the lower left side and became more flat, due to the long-term aging. The aged binder (AB) has shown a lower phase angle indicating the loss of viscosity. With regards to the rejuvenated binders, reB-B and reB-F show the same trend as AB and the curves located between the threshold curves (R=2 and R=3), indicating that these two types of rejuvenated binders tend to be viscous. While, reB- C and reB-E show a downward shift, indicating the Rej C and Rej E have an adverse effect on the viscoelasticity. For further anti-cracking analysis of the rejuvenated binders, the Glower-Rowe parameter was calculated and added in Figure 4-5. It is defined as G'/sind and measured at 15°C and 0.005 rads-1, which was found to give a good correlation with ductility and cracking resistance. As illustrated in Figure 4-5, the G-R parameter of AB is over the threshold value (G- R=450), indicating that the aged PMB binders had a high risk of cracking without rejuvenation. With the addition of rejuvenators, GR parameters of reB-B, reB-E and reB-F are below 180 kPa, implying there is no cracking risk.

The aging stability of already rejuvenated binders has a significant impact on the potential reusability of RAP binders, so the rejuvenated binders are also subjected to a second aging cycle. To simulate the aging during service on the road, the rejuvenated bitumen was again aged in RTFOT and after that 80 hours of PAV aging. For a clear comparison of the viscoelastic properties before and after aging, the master-curves of rejuvenated binder and aged binder are plotted in Figures 6-

7. As it is observed in Figures 6-7, the change in

P100422NL00 14 viscoelastic properties of aged SBS modified binder after the second aging cycle (AB) is similar to the change from OB to AB. The complex modulus curve shifts upwards and the phase angle master-curve shifts downwards, indicating that the AB aged becomes stiffer and more elastic. The reB-B, reB-E and reB-F binders have shown a significant rejuvenation effect, reduction in complex modulus and an increase in phase angle. However, after the second aging cycle, the complex modulus of aged reB-E aged, reB-F and AB binders are almost the same indicating that the rejuvenation effect disappears during the second aging phase. For the phase angle, the master-curves of reB-E and reB-F are even lower, indicating that the rejuvenation has an adverse effect, resulting in a higher elastic response. On the contrary, the rejuvenation effect of rejuvenator B is very significant. The complex modulus and phase angle difference between reB-B aged and AB aged are even larger than of reB-B and AB, indicating that the Rej-B can reduce the influence of a second aging phase to a certain extent.

To develop a tool for practice to choose the most suitable rejuvenators for aged PMB binders, a simple ranking method was introduced based on the seven tests discussed earlier. Firstly, the studied materials are ranked for each test. The highest-ranked materials obtain a ranking value (RV) of 6, and the last one is ranked with 1 RV. Then, by summing up the RV for each binder, the total rank value (TRV) is given for this material. The RV and TRV of the rejuvenated bitumen are plotted in a radar chart. The RV results can be seen in Figure 8, and it shows contrasting values between ageing stability and the medium/low- temperature performance-based properties Figure 8. For example, reB-E has shown advantages in fatigue and low- temperature properties but drawbacks in aging stability.

However, reB-B has shown the highest TRV and either rank first or second in most of the performance-based properties, indicating that Rej-B can keep the balance on both sides and probably is a very efficient rejuvenator in all aspects. In

P100422NL00 15 this case, the added SBS polymer played a very important role in compensating the loss of SBS polymer, and at the same time, the degradation of SBS can reduce the aging of the base asphalt.

The determination of rejuvenator dosage in the recycling of RAP is a practical concern. The traditional method is to determine the rejuvenator dosage according to rejuvenated bitumen’s penetration and softening point values. In this research, it is found that a series of performance-based tests can also be used to determine the rejuvenator dosage in recycling. For example, the relaxation tests were performed at 0 °C, with 1% shear strain (in 0.1 seconds) at the beginning and followed by 100 seconds of relaxation time. As illustrated in Figure 9, the maximum stress at 0.1s showed an exponential relationship with the rejuvenator dosage added to the aged PMB.

An exponential fitted curve can be established between the maximum stress and rejuvenator dosage. As the maximum stress of original PMB has been tested, the rejuvenator dosage to recover rejuvenated binder’s maximum stress to its original state can be calculated according to the exponential fitted curve.

A promising technique for observing asphalt microstructure is the E-SEM. The electron beam emitted by the E-SEM displaces the lighter binder molecules, revealing a microstructure, which has been shown to correspond to the resins and possibly a part of the asphaltenes fraction of the binder. As illustrated in Figure 10, the morphology of bitumen is mainly influenced by the aging state, rejuvenator dosage, rejuvenator type and addition of fresh bitumen. From the comparison of (a) and (b), the “worm structure” tend to be smaller, denser and coarser during the aging process. As shown in (cc), the addition of 10% Rej B led the “worm structure” relatively larger and smoother, which is similar to that of original PMB. In the comparison of (cc), (d) and (e}, the increase of rejuvenator dosage led the “worm

P100422NL00 16 structure” to be larger and thicker. When rejuvenator dosage is the same (30%), the significant difference in (ee), (f) and (g) indicates that the rejuvenator type also influences the “worm structure”. Furthermore, when the rejuvenated binder was mixed with the fresh PMB, the morphology is not homogeneous, indicating the inhomogeneity of the miscibility state between fresh and aged PMB. For the sake of searching the following section is added which represents a translation of the subsequent section.

1. Rejuvenator for a polymeric network comprising 1-25 wt.% of at least one substantially intact polymer, preferably 3-20 wt.%, more preferably 4-15 wt.3, such as 5- 11 wt.%, 15-50 wt.% of at least one aromatic oil, such as a synthetic or natural aromatic oil, preferably 20-45 wt.2, more preferably 25-40 wt.%, such as 30-35 wt.?%,

0.3-10 wt.% of at least one additives, wherein the at least one additive is preferably selected from terpenes, preferably 0.5-5 wt.%, more preferably 1-4 wt.%, such as 2-3 wt. 2, 30-75 wt.% of at least one saturated acidic oil, preferably 35-68 wt.%, more preferably 40-63 wt.%, such as 47-55 wt.%,

0.4-10 wt.% of at least one resin for activating polymeric network, preferably 0.5-5 wt.%, more preferably 1- 4 wt.%, such as 2-3 wt.%, wherein all weight percentages are based on the total weight of the rejuvenator.

2. Rejuvenator for a polymeric network according to embodiment 1, wherein the polymeric network is selected from polymer modified bitumen, modified asphalt comprising a polymer, such as modified asphalt concrete.

3. Rejuvenator for a polymeric network according to any of embodiments 1-2, wherein the polymer is selected from co- polymers, preferably comprising a flexible domain, such as from linear copolymers, such as block copolymers, alternating copolymers, periodic copolymers, statistical

P100422NL00 17 copolymers, stereo-block copolymers, and gradient copolymers, branched copolymers, and graft copolymers, preferably from ethylene-butyl-acrylate (EBA), styrene- butadiene-styrene (SBS), and natural or synthetic rubber.

4. Rejuvenator for a polymeric network according to any of embodiments 1-3, wherein the aromatic oil comprising at least one aromatic moiety has an aromatic content of > 25%, preferably >30%, more preferably > 40%, even more preferably >50%, such as > 653%.

5. Rejuvenator for a polymeric network according to any of embodiments 1-4, wherein the aromatic oil is selected from rubber processing oil, vacuum third residual from crude oil, reduced crude oil, synthetic or natural aromatic oil, mineral oil, and combinations thereof.

6. Rejuvenator for a polymeric network according to any of embodiments 1-5, wherein the aromatic oil is adapted to dissolve asphaltene, wherein the aromatic oil may be provided as a liquid comprising 10-65 wt. % solvent.

7. Rejuvenator for a polymeric network according to any of embodiments 1-6, wherein the at least one additive is selected from organic solvents, such as asphaltene solvents, such as monoterpenes (CioHis), preferably cyclic- or bicyclic monoterpenes, such as geraniol, terpinecl, limonene, myrcene, linalool, and pinene, sesquiterpenes (CisHz4), such as humulene, farnesenes, and farnesol, diterpenes (CzoHs2), such as cafestol, kahweol, cembrene, and taxadiene, triterpines (C:9Ha4s), such as squalene.

8. Rejuvenator for a polymeric network according to any of embodiments 1-7, wherein the at least one saturated acidic oil is an oil with more than 16 carbons and at least one carboxylic acid, such as more than 20 carbons and at least one carboxylic acid, such as rapeseed oil, .

9. Rejuvenator for a polymeric network according to any of embodiments 3-8, wherein the at least one resin is selected from hydrocarbon resins, such as C4 Ci: resins, preferably Cs-Cis resins, more preferably Cs-Cs resins.

10. Reclaimed polymeric network, such as reclaimed modified bitumen, comprising 1-20 wt.% of at least one rejuvenator

P100422NL00 18 according to any of embodiments 1-9, such as 2-15 wt.%, and rejuvenated aged polymer modified bitumen, wherein the polymer in the modified bitumen is preferably selected from block polymers, such as styrene-butadiene-styrene (SBS) polymer, natural or synthetic latex, such as polychloroprene latex, and reclaimed rubber.

11. Asphalt product comprising reclaimed polymer modified bitumen according to embodiment 10, or a rejuvenator according to any of embodiments 1-9.

12. Asphalt according to embodiment 11, further comprising one or more of particles, coarse aggregate, filler, extender, fibres, oxidants, anti-oxidants, plastics, anti- stripping agents, and waste material.

13. Construction comprising asphalt according to any of embodiments 11-12, wherein the construction is selected from a multilayer civil engineering system, such as an asphalt concrete surfacing layer on orthotropic steel deck bridge, a foundation, a wall, a basement, a building, and combinations thereof, and/or wherein the construction comprises at least one of a waterproofing, a top layer, and a deck layer.

14. Method of applying a rejuvenator for a polymeric network according to any of embodiments 1-9, comprising mixing the rejuvenator and aged polymer modified bitumen, pre-heating the mixture to a temperature of 350-433 K(77-160 °C) during a pre-heating period of time, heating the mixture to a temperature of 430-473 K{157-200 °C) during a heating period of time, maintaining said temperature for at least 1 minute, cooling the mixture, and applying the mixture, such as to a road.

15. Use of a rejuvenator for a polymeric network according to any of embodiments 1-9 for healing the polymeric network, for improving viscoelasticity, enhancing colloidal stability, dissolving asphaltene, improving durability, improving anti-cracking, improving aging resistance, improving compatibility, improving relaxation, increasing maximum stress, or a combination thereof.

Claims

P100422EN00 19 Conclusions

A polymer network rejuvenator comprising 1-25 wt.% of at least one substantially intact polymer, preferably 3-20 wt.%, more preferably 4-15 wt.%, such as 5-11 wt.5, 15-50 wt.3 of at least one aromatic oil, such as a synthetic or natural aromatic oil, preferably 20-45 wt.%, more preferably 25-40 wt.%, such as 30-35 wt.%, 0.3-10 wt.% of at least one additive, wherein at least one additive is preferably selected from terpenes, preferably 0.5-5 wt.%, more preferably 1-4 wt.%, such as 2-3 wt.%, 30- 75 wt.% of at least one saturated sour oil, preferably 35-68 wt.%, more preferably 40-63 wt.%, such as 47-55 wt.#%, 0.4-10 wt.% of at least one resin for activating the polymeric network, preferably 0.5-5 wt.%, more preferably 1-4 wt.%, such as 2-3 wt.3%, wherein all weight percentages are based on the total weight of the rejuvenation machine.

A polymer network rejuvenating agent according to claim 1, wherein the polymer network is selected from polymer bitumen, modified asphalt composed of a polymer, such as modified asphalt concrete.

A polymer network rejuvenator according to claim 1-2, wherein the polymer is selected from copolymers, preferably comprising a flexible domain, such as from linear copolymers, such as block copolymers, alternating copolymers, periodic copolymers, random copolymers, stereoblock copolymers, and gradient copolymers branched copolymers, and graft copolymers, preferably of ethylene-butyl acrylate (EBA), styrene-butadiene-styrene (SBS), and natural or synthetic rubber.

A polymer network rejuvenating agent according to any one of claims 1 to 3, wherein said aromatic oil

P100422EN00 20 comprises at least one aromatic moiety has an aromatic content of > 25%, preferably >30%, more preferably > 40%, even more preferably >503, such as >653,

A polymer network rejuvenator according to any one of claims 1-4, wherein the aromatic oil is selected from rubber processing oil, a vacuum third residue of crude oil, reduced crude oil, synthetic or natural aromatic oil, mineral oil, and combinations thereof.

A polymer network rejuvenator according to any one of claims 1-5, wherein the aromatic oil is adapted to dissolve asphalt, wherein the aromatic oil may be provided as a liquid containing 10-65 wt. + solvent included.

A polymer network rejuvenator according to any one of claims 1-6, wherein the at least one additive is selected from organic solvents, such as asphaltene-containing solvents, such as monoterpenes (C10His), preferably cyclic or bicyclic monoterpenes, such as geraniol, terpineol, limonene , myrcene, linalool, and pinene, sesquiterpenes (CisHza), such as humulene, farnesenes, and farnesol, diterpenes (C:29H32), such as cafestol, kahweol, cembreen, and taxadiene, triterpines (C39H4s)}, such as squalene.

A polymer network rejuvenator according to any one of claims 1 to 7, wherein the at least one saturated acidic oil is an oil having more than 16 carbons and at least one carboxylic acid, such as more than 20 carbons and at least one carboxylic acid, such as rapeseed oil .

A polymer network rejuvenator according to any one of claims 3-8, wherein the at least one resin is selected from hydrocarbon resins, such as C4-C11:2 resins, preferably C5-C10 resins, preferably C5-C8 resins.

A regenerated polymer network, such as regenerated modified bitumen, comprising 1-20 wt.% of at least one rejuvenating agent according to any one of claims 1-9, such as 2-15 wt.%, and regenerated modified polymer,

P100422NL00 21 wherein the polymer in the modified bitumen is preferably selected from block polymers, such as styrene-butadiene-styrene (SBS), natural or synthetic latex, such as polychloroprene latex, and regenerated rubber.

An asphalt product comprising recovered polymer modified bitumen according to claim 10, or a rejuvenating agent according to any one of claims 1-9.

The asphalt of claim 11, further comprising one or more of particulates, coarse aggregate, filler, extender, fibers, oxidizing agents, antioxidants, plastics, anti-stripping agents, and waste material.

A construction comprising asphalt according to claims 11-12, wherein the construction is selected from a multi-layer civil engineering system, such as an asphalt concrete layer on an orthotropic steel deck bridge, a foundation, a wall, a basement, a building, and combinations thereof, and/or wherein the construction comprises at least one of a waterproofing, a top layer, and a cover layer.

A method of applying a rejuvenating agent to a polymer network according to any one of claims 1-9, comprising mixing the rejuvenating agent and the aged polymer-modified bitumen, preheating the mixture to a temperature of 350-433 K(77-160 °C) for a preheating period, heating the mixture to a temperature of 430-473 K{ (157-200 °C) for a heating period, maintaining this temperature for at least 1 minute, cooling the mixture and applying the mixture, for example on a road.

Use of a polymer network rejuvenating agent according to any one of claims 1-9 for restoring the polymer network, improving viscoelasticity, improving colloidal stability, dissolving asphaltene, improving durability , improve the anti-cracking, it

P100422NL00 22 improve aging resistance, improve compatibility, improve relaxation, increase maximum stress, or a combination thereof.