Field of the invention

The present invention relates to bituminous binder compositions and asphalt compositions, roofing coverings, bituminous membranes and bituminous fabrics comprising said bituminous binder compositions.

Background of the invention

Employing combinations of virgin bitumen and recycled asphalt in asphalt compositions to reduce the amount of virgin bitumen in asphalt compositions is known in the art. Substitution of virgin bitumen is commonly done due to the sharp rise of costs of virgin bitumen and for environmental reasons. However, the application of recycled asphalt has disadvantageous properties since the bitumen contained therein is, mainly due to oxidative processes and to the evaporation of lighter components, less resistant to deformation, more brittle and less flexible (i.e., "hardening" of the bitumen) than virgin bitumen, which results in asphalt compositions having a moderate elastic behaviour. The hardening of bitumen leads to an increase of stiffness at higher temperatures, an increase of brittleness at lower temperatures, and an increase of viscosity. A stiffness increase at higher temperatures may be beneficial since the asphalt containing the hardened bitumen is less vulnerable to deformation and can withstand higher loads. However, a brittleness increase is disadvantageous because it reduces the resistance to break at higher loads. Virgin bitumen has a better viscoelastic behaviour than hardened bitumen which enables self-repair of the asphalt layer in times of less traffic loads. Additionally, the viscosity increase has the disadvantage that the mixing and application temperatures of the asphalt composition (when the asphalt composition only comprises virgin bitumen, mixing is usually performed at about 170 ⁰ C and application is usually performed at about 140 ⁰ C) must be increased with about 50 ⁰ C. This is obviously undesired. Consequently, to improve the viscosity properties, an additive is added to hardened bitumen to reduce the viscosity to a value that approaches the viscosity of virgin bitumen. For example, US 5.217.530, incorporated by reference, discloses asphalt compositions comprising 3 - 8 parts by weight of virgin bitumen, 62 - 96 parts by weight of aggregate material and 0.5 - 30 parts by weight of recycled roof waste, said recycled roof waste being size-graded to a dimension of less than 1.0 mm and comprising about 5 - 15 wt.% of fibre and about 40 - 70 wt.% of filler. The recycled roof waste is used as the predominant source of bituminous binder. The virgin bitumen preferably has a penetration of 15 - 200, more preferably 20 - 50 10 ^"1 mm. The recycled roof waste is most preferably "recycled asphalt roofing waste" which is available from ReClaim Inc., Tampa, Florida.

US 5.340.391, incorporated by reference, discloses asphalt compositions comprising virgin bitumen, asbestos and recycled roof waste. However, such compositions are environmentally very unfriendly since they contain asbestos fibres which upon inhalation may causeserious illness, e.g. mesothelioma and asbestosis. The roof waste that is preferably used in the invention disclosed in US 5.340.391 is also "recycled asphalt roofing waste" which is available from ReClaim Inc., Tampa, Florida, and this material comprises about 5 - 15 wt.% of fibre, about 40 - 70 wt.% of filler and about 30 - 40 wt.% of hardened bitumen.

Asphalt compositions comprising recycled roof waste according to the prior art often provided a too brittle material as discussed above whereas highly elastic asphalt must often be used in road construction for areas of high traffic rates and high traffic loads. Hence, to enhance the elasticity of the asphalt composition comprising recycled bitumen, crumb rubber may be added as an additive. Reference is made to US 5.436.285, US 2005/0011407 and US 2006/0249049, all incorporated by reference. Alternatively, diluting agents or rejuvenating oils have been added as additives to the asphalt compositions comprising recycled bitumen to increase elasticity of said asphalt compositions and to allow the incorporation of higher amounts of recycled bitumen. For example, US 6.186.700, incorporated by reference, discloses asphalt compositions comprising recycled asphalt granules (obtained from recycled roof waste or recycled asphalt pavement), aggregate mineral material, a rejuventating oil and an emulsifier. US 2006/0215483, incorporated by reference, discloses asphalt compositions comprising recycled asphalt, virgin bitumen (penetration of 20 - 300, preferably 50 - 250, more preferably 75 - 200 10 ^"1 mm) and a terpenoid liquid as diluting agent. DE 102004055474, incorporated by reference, discloses an asphalt composition comprising aggregate material, virgin bitumen, recycled asphalt granules and a flux oil as a diluting agent.

EP A 8 10.276, incorporated by reference, discloses a method for recycling asphalt, wherein at least two fractions of used asphalt, each fraction having a different particle size, are heated separately and subsequently mixed with virgin bitumen.

US 6.159.279, incorporated by reference, discloses an asphalt-fines matrix comprising aggregate material, 1 - 70 wt.% of roadway millings and 2.5 - 6.0 wt.% of a hard bitumen having a penetration of 10 - 30 cm ¹ . During the manufacture of the asphalt-fines matrix, it is said that it is not necessary to regenerate the aged bituminous binder in the roadway millings so that different types of millings can be recycled without the need to sort these types first. The aged binder bituminous binder content of the roadway millings is at least 3 wt.% in relation to the aggregates.

WO 2008/084014, incorporated by reference, discloses a rejuvenating agent having a viscosity of 200 - 6000 cSt (60 ⁰ C) which comprises 10 - 90 wt.% palm oil and 10 - 90 wt.% bitumen, based on the total weight of the rejuvenating agent, and a process of recycling asphalt comprising the addition of the rejuvenating agent.

KR 100781608 Bl, incorporated by reference, discloses compositions comprising recycled asphalt, elastomer and a petroleum resin. The present inventors have found that the flexibility of the incorporation of recycled asphalt in asphalt compositions can be further improved, in particular in terms of hardness, brittleness, viscosity and fatigue resistance.

Summary of the invention

The present invention relates to a bituminous binder composition comprising:

(a) a recycled hard bitumen having a penetration according to NEN-EN 1426 (2007) at 25°C of 5 - 80 10 ^"1 mm; and

(b) a rejuveniling resin, wherein the rejuveniling resin comprises a phenolic compound having at least one unsaturated side-chain, and oligomers and polymers including the phenolic compound, wherein the phenolic compound is characterised by the formula:

wherein R is CisH ₃ i_ _n and wherein n = 0, 2, 4 or 6.

The present invention further relates to a bituminous binder composition comprising:

(a) a recycled hard bitumen having a penetration according to NEN-EN 1426 (2007) at 25°C (similar to ASTM D5-97 at 25°C (5 s, 100 g)) of 5 - 80 10 ^"1 mm; and

(b) an additive composition comprising rejuveniling resin composition and an elastomer; wherein the bituminous binder composition comprises an amount of the additive composition, based on the total weight of the bituminous binder composition, according to the formula:

wt.% additive composition < 0.3 * wt.% recycled hard bitumen.

wherein the amount of recycled hard bitumen in the bituminous binder composition is 70 - 100 wt.%, based on the total weight of the total bitumen content of the bituminous binder composition, and wherein the rejuveniling resin preferably comprises a phenolic compound having at least one unsaturated side-chain, and oligomers and polymers including the phenolic compound, wherein the phenolic compound is characterised by the formula:

wherein R is Ci ₅ H ₃ i_ _n and wherein n = 0, 2, 4 or 6. The present invention further relates to asphalt compositions, roofing coverings, bituminous membranes and bituminous fabrics comprising the bituminous binder compositions.

Detailed description of the invention

Definitions

The verb "to comprise" as is used in this description and in the claims and its conjugations is used in its non- limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there is one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".

In this document, the term "asphalt" is to be understood as a mixture comprising a bituminous binder composition and aggregate material (in the US often referred to as "asphalt concrete"). The term "bitumen" (in the US often referred to as "asphalt") is to be understood as a mixture of highly viscous, black organic compounds of which the major part are highly condensed polycyclic aromatic hydrocarbons. The bitumen may be naturally occurring bitumen, crude bitumen or the bitumen may be refined bitumen obtained as the bottom residue in the vacuum distillation process of crude oil, thermal cracking processes or hydrogen cracking processes. The CAS-number of bitumen is 8052-42-4. For the distinction between the terms "asphalt" and "bitumen", reference is further made to Kirk-Othmer, Encyclopedia of Chemical Technology, 4 ^th Ed., Vol. 3, 689 - 724, 1992.

The term "aged bitumen" or "hardened bitumen" is used in this document to indicate bitumen in its form after extensive use in asphalt and which has been recycled. "Aged" or "hardened" bitumen is therefore distinct in properties such as penetration when compared with virgin or fresh bitumen as is explained above. In this document, the terms "aged bitumen" and "hardened bitumen" are interchangeably used.

In this document, the term "recycled hard bitumen" means the reuse of bitumen which are present in roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof. Although recycled hard bitumen and aged or hardened bitumen have properties in common, they originate from different sources. The reason for this is that virgin bitumen used in roofing applications, membranes and fabrics are often different from virgin bitumen in road applications. The term "virgin bitumen" and the term "fresh bitumen" as used in this document mean bitumen in their virgin or fresh state, i.e. that they have not been used in applications such as asphalt, roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof and are in a state as bitumen which are directly delivered from the bitumen manufacturer or supplier.

Bituminous binder composition

The amount of recycled hard bitumen comprised by the bituminous binder composition is 70 - 100 wt.%, based on the total weight of the total bitumen content of the bituminous binder composition. The remaining 0 - 30 wt.% of the total bitumen content is either aged (or hardened) bitumen, preferably from recycled asphalt granulate, virgin bitumen, or a mixture of aged bitumen and virgin bitumen. The recycled hard bitumen preferably originates from roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof. The recycled hard bitumen has preferably a penetration of 5 - 70 10 ^"1 mm, more preferably 5 - 60 10 ^"1 mm, yet even more preferably 10 - 60 10 ^"1 mm.

According to a preferred embodiment of the present invention, the bituminous binder composition comprises an amount of the additive composition according to the formula:

wt.% additive composition < 0.3 * wt.% recycled hard bitumen

and more preferably according to the formula:

wt.% additive composition < 0.25 * wt.% recycled hard bitumen

Hence, according to the invention, it is therefore preferred that the higher the recycled hard bitumen content, the higher the additive composition content. According to the present invention, it is preferred that the recycled hard bitumen is a recycled roofing-grade bitumen, preferably obtained from roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof, which have been obtained from for example demolition, replacing or reconstruction operations, as well as cutting waste or failed production materials obtained in the production of roofing coverings, bituminous membranes and bituminous fabrics, wherein the roofing-grade bitumen is preferably a blown bitumen or a polymer modified bitumen, wherein the polymer is preferably a styrene-butadiene polymer or atactic polypropylene, most preferably atactic polypropylene. The styrene-butadiene polymer content is usually about 10 - 20 wt.%, based on the total weight of the polymer modified bitumen, and the atactic polypropylene is usually about 20 - 40 wt.%., based on the total weight of the polymer modified bitumen. The softening point of bitumen modified with atactic polypropylene is usually in the order of 155°C and the softening point of bitumen modified with a styrene-butadiene polymer is usually in the order of 115° - 120 ⁰ C. It is well known in the art that roofing-grade bitumen are distinct from road-paving grade bitumen, the latter usually having a relatively lower penetration and a relatively lower softening point. Even more preferably, the recycled roofing grade bitumen are comprised by a granulate made from roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof which have been obtained from for example demolition, replacing or reconstruction operations, as well as made from cutting waste or failed production materials. This implies that this bitumen is not first recycled and isolated as such. However, as will be apparent to the skilled person in the art, the bitumen may first be recovered from this granulate and then used in the bituminous binder compositions according to the present invention. According to the present invention, it is preferred that the roofing-grade bitumen which has been used for the manufacture of the roofing coverings, bituminous membranes, bituminous fabrics and similar materials has a softening point (ASTM D-36, Ring-and-Ball) of 50° - 300°, more preferably 75° - 250° and in particular 85° - 200 ⁰ C.

Where the term "polymer modified bitumen" is used herein, the "polymer" is to be understood as distinct from the elastomer used in the additive composition which is a component of the bituminous binder compositions according to the present invention. Most preferably, the recycled roofing grade bitumen are from a granulate made from roofing coverings. Such granulates usually consist of a support (e.g. glass or polyester woven or non-woven fabrics), bitumen, filling materials, sand and/or shale).

Blown bitumen is known in the art and are commonly manufactured by passing air or another oxygen containing gas over the bitumen. This results in an increase of the asphaltene content, an increase of the molecular weight and to the incorporation of ester functionalities which results in an increase in stiffness and softening point (Ring- and Ball). However, such blown bitumen are usually less compatible with modifying polymers and blends of blown bitumen and modifying polymers have a low storage stability. Nevertheless, methods are known in the art to provide stable blends of blown bitumen and elastomers. Hence, according to the present invention, the blown bitumen may comprise one or more elastomers.

Polymer modified bitumen is also known in the art and comprises bitumen modified with one or more elastomers. Polymer modification is usually employed to improve the ductility of the bitumen and to reduce the breaking point ( ⁰ C) according to the FRAAS test (test 80/53 of the Institute of Petroleum). It provides an approximate indication of the temperature at which bitumen has no ductility and would reflect brittle fracture conditions. According to the invention, the breaking point of the polymer modified bitumen is preferably between 0 and -30 ⁰ C, more preferably -5° to -25°C. Since about 1940, the use of polymer modified bitumen in roofing coverings increased considerably at the expense of blown bitumen.

According to the present invention, the additive composition comprises a rejuveniling resin composition and an elastomer (which is distinct from the polymer used in polymer modified bitumen).. The rejuveniling resin composition preferably comprises a rejuveniling resin which is preferably selected from the group consisting of natural rejuveniling resins, synthetic rejuveniling resins, and mixtures thereof. These rejuveniling resins comprise phenolic compounds having at least one unsaturated side-chain, and oligomers and polymers including such phenolic compounds. The major components of these phenolic compounds are generally characterised by the formula:

wherein R is CisH ₃ i_ _n (n = 0, 2, 4 or 6) and are often referred to as "cardanol". Other phenolic components have a similar structure, wherein R is an optionally unsaturated C ₁₃ or C ₁₇ aliphatic, saturated or unsaturated chain. The oligomers and polymers may be formed during processing of vegetable oils, e.g. distillation where the oligomers and polymers are obtained as a residue, of may be synthetically formed from the monomeric phenolic compounds.

The rejuveniling resin is preferably derived from phenolic compounds having at least one unsaturated side-chain, and oligomers and polymers including such phenolic compounds components as present in unrefined Cashew Nut Shell Liquid (CNSL) and similar materials, most preferably CNSL. CNSL is a natural resin found in the honeycomb structure of the cashew nutshell. The oligomers and polymers may optionally be hydrogenated. Reference is made to e.g. US 2.523.623. Most preferably, the rejuveniling resin is based on the residue of the distillation of unrefined CNSL. This residue majorly consists of oligomers and polymers of the phenolic components described above and has a viscosity (25°C) of about 1.000 - 30.000 mPa.s ^"1 , more preferably 1000 - 6000 mPa.s ^"1 and most preferably 1100 - 3000 mPa.s ^"1 . Suitable rejuveniling resins include Rheofalt EM and EMC which are commercialised by van Weezenbeek Specialties, Heerhugowaard, The Netherlands. The rejuveniling resin may be a blend of such resins and may further comprise an oil and/or a wax with a low softening point and a high penetration. It is preferred that the rejuveniling resin composition comprises 20 - 100 wt.% of a rejuveniling resin and 0 - 80 wt.% other components selected from oils, waxes and mixtures thereof, said other components comprising > 1.0 wt.% but less than 10 wt.% aromatic compounds, based on the total weight of the other components concerned. These weight ranges are based on the total weight of the rejuveniling resin composition. More preferably, the rejuveniling resin composition comprises 50 - 100 wt.% of a rejuveniling resin and 0 - 50 wt. % other components, even more preferably 75 - 100 wt.% of a rejuveniling resin and 0 - 25 wt.% other components. Most preferably, the rejuveniling resin composition consists essentially of the rejuveniling resin. Preferably, the rejuveniling resin composition lowers the viscosity of the bituminous binder compositions according to the present invention.

It is furthermore preferred that the amount of the additive composition in the bituminous binder composition is in the range of 0 - 30 wt.%, preferably 0.1 - 30 wt.%, based on the total weight of the bituminous binder composition, provided that the bituminous binder composition comprises an amount of the additive composition according to the formula:

wt.% additive composition < 0.3 * wt.% recycled hard bitumen.

Hence, the bituminous binder composition comprises a total bitumen content of 70 - 100 wt. and 0 - 30 wt.% of the additive composition, preferably a total bitumen content of 70 - 99.9 wt.% and 0.1 - 30 wt.% of the additive composition, even more preferably a total bitumen content of 70 - 90.5 wt.% and 0.5 - 30 wt.% of the additive composition. The amount of recycled hard bitumen comprised by the total bitumen content is 70 - 100 wt.% as described above. The elastomer of the additive composition is preferably selected from the group consisting of ethylene-vinyl acetate copolymers, polybutadienes, ethylene-propylene copolymers, ethylene-propylene-diene terpolymers, butadiene-styrene diblock copolymers, styrene-butadiene-styrene (SBS) triblock terpolymers, isoprene-styrene diblock copolymers and styrene-isoprene-styrene (SIS) triblock terpolymers. In the bituminous binder composition according to the present invention, the elastomer content is preferably 0.1 to 15.0 wt. %, more preferably 0.1 to 5.0 wt. %, based on the total weight of the bituminous binder composition.

It is also preferred that the weight ratio between the rejuveniling resin composition and the elastomer is between 50 : 50 and 99.9 : 0.1, more preferably 50 : 50 and 99 : 1, and most preferably 50 : 50 and 90 : 10, based on the total weight of the additive composition.

Preferably, the bituminous binder composition according to the present invention further comprise, filler, mineral aggregate and optionally fibres and (woven or non- woven) fabrics, because the bitumen source for the bituminous binder composition is preferably a granulate made from roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof preferably obtained from roofing coverings, bituminous membranes, bituminous fabrics or mixtures thereof, as well as cutting waste or failed production materials.. This granulate has preferably a mean diameter of 1 - 40 mm, more preferably 5 - 30 mm.

According to the present invention, the bituminous binder compositions show a viscoelastic behaviour. In rheological tests, a transition (inflection point in the Young modulus - temperature diagram) is observed from an elastic behaviour to a viscous behaviour. For a conventional virgin bitumen (penetration 40 - 60 cm ^"1 ), this transition is observed around 10 ⁰ C. According to the present invention, the bituminous binder composition preferably has this transition between 20° - 70 ⁰ C, more preferably between 25° - 50°.

Asphalt compositions

The present invention also relates to the use of the bituminous binder composition according to the present invention, in asphalt compositions and asphalt-related compositions comprising aggregate material and the bituminous binder composition according to the invention.

According to a preferred embodiment, the asphalt composition comprises recycled asphalt, said recycled asphalt comprising 0.1 - 25 wt.% "aged" bitumen

(wherein the term "aged" refers to the bitumen in its form after the extensive use of the asphalt), preferably 0.5 - 15 wt.%, more preferably 1 - 10 wt.%, based on the total weight of the recycled asphalt.

According to another preferred embodiment of the invention, the asphalt composition further comprises a variable weight ratio of aged bitumen as comprised by the recycled asphalt and the recycled hard bitumen as comprised by the bituminous binder composition, wherein this ratio varies between 99 : 1 to 1 : 99, based on the total weight of the bitumen content of the asphalt composition. More preferably, this weight ratio varies between 50 : 10 to 50 : 90 and most preferably between 25 : 10 to 75 : 90.

According to yet another preferred embodiment of the invention, the asphalt composition only comprises the recycled hard bitumen as comprised by the bituminous binder composition, i.e. that the recycled hard bitumen is the only bitumen source used in the asphalt composition. In such asphalt compositions, the bituminous binder composition according to the invention consists essentially of the recycled hard bitumen and the additive composition and is preferably used as a hot binder. According to the invention, it is preferred that the asphalt composition comprises

0.1 - 15 wt.% bitumen, wherein the bitumen are selected from the group of virgin bitumen, recycled hard bitumen (preferably from roof covering granulate), aged bitumen (preferably from asphalt granulate) and mixtures thereof.

The total amount of the combination of aged bitumen (as comprised by the recycled asphalt) and recycled hard bitumen (as comprised by the bituminous binder composition) in the asphalt composition depends on the required total binder properties. However, this total amount is generally 0.1 - 25 wt.% total bitumen, based on the total weight of the asphalt composition, preferably 0.5 - 15 wt.%, more preferably 1 - 10 wt.%, based on the total weight of the asphalt composition. According to the present invention, asphalt-related compositions include roofing covering compositions, bituminous membrane compositions and bituminous fabric compositions.

Examples

Example 1

The following asphalt compositions were prepared: ZOAB = porous asphalt,

STAB = asphalt concrete base course and asphalt concrete binder course, DAB = asphalt surface course, SMA = stone mastic asphalt. The bitumen content of the roof covering granulate was 5 wt.%. The rejuvenilin resin was Rheofalt EM and the elastomer was Kraton® Dl 118. The compositions are shown in Table 1. Table 1

Weight ratio rejuveniling resin composition and elastomer is 1 : 1.

Penetration measurements according to NEN-EN 1426 (or its equivalent ASTM D5) may officially only be performed on virgin or fresh bitumen. The properties of the asphalt compositions were therefore established in a test in which the penetration in the composition as such was determined, wherein a similar asphalt composition based on a 40/60 bitumen (virgin; penetration according to NEN-EN 1425 (2007) at 25°C of 40 10 ^"1 mm to 60 10 ^"1 mm) was used as a reference. This test (NEN-EN 12697-20) is normally used for testing mastic asphalt and the stiffening effect of the filler materials is taken into account. The performance of the asphalt compositions according to Table 1 was on a par with the performance of the reference based on a 40/60 bitumen.

Example 2

The following mixtures of roof covering granulate, recycled asphalt granulate and additive composition (weight ratio rejuveniling resin composition and elastomer is 1 : 1). The rejuveniling resin was Rheofalt EM and the elastomer was Kraton® Dl 118. The mixtures are shown in Table 2.

Table 2

a 40/60 means a penetration of 40 - 60 x 10 mm (25°C).

The viscoelasticity of the compositions of Table 2 were measured at a frequency of 1 Hz at variable temperature. The results are shown in Table 3 and Figures IA and IB. Figure IA shows the data of samples 1 , 5 and 10. Figure IB shows the data of samples 7, 8 and 10.

From Figure IA and Table 3, it appears that the inflection point for mixture 10 is around 10 ⁰ C. The inflection point indicates the transition from elastic behaviour to viscous behaviour. The inflection points for mixtures 1 - 6 are around 50° - 75°C. The inflection points for mixtures 7 and 8 are around 135° - 145°C (cf. Figure IB). This example demonstrates that the compositions are more sensible to deformation at higher temperatures. Table 3

G* (Pa - Elastic

Sample TfC) -25 0 25 50 75 100 125 150

1 8800 8000 7800 5300 4000 4000 4000 4000

2 8800 8000 7800 5300 4200 2900 2900 2900

3 8800 8000 6800 5500 4500 3300 2500 2500

4 8500 7800 6700 5500 4700 3700 2800 2800

5 8800 7800 6800 5800 4800 4000 3000 3000

6 8600 7800 6800 5600 4200 3200 2800 2800

7 6500 6400 6300 5800 5500 4600 3800 3400

8 8500 7700 6700 5800 5000 4400 3700 3700

10 8800 7800 5600 3200 3200 3200 3200 3200

Sample TfC) G* (Pa) - Viscous

1 7900 7600 6700 5200 4300 3100 3100 3100

2 7900 7600 6700 6300 4200 3300 3300 3300

3 7900 7600 6700 5500 4600 3800 2800 2800

4 7700 7300 6400 5500 4600 3800 3000 3000

5 7900 7500 6700 5700 4800 4000 3300 3300

6 7800 7500 6600 5600 4700 3700 2800 2800

7 5900 6000 5900 5500 4800 4400 3600 3600

8 7800 7200 6400 5600 4800 4200 3500 3500

10 7700 7600 6000 4000 4000 4000 4000 4000

Example 3

The following mixtures were studied by dynamic shear rheology and by dynamic viscosity measurements. These mixtures correspond to mixing ratios which can be selected for asphalt mixtures containing roof covering granulate and asphalt granulate. The mixtures are shown in Table 4.

Table 4

a DBA: bitumen from roof covering granulate which contains about 23 wt.% hardened bitumen ^b AG: bitumen from asphalt granulate which contains about 4.8 wt.% hardened bitumen. ^c Rheovalt EM. ^d Virgin bitumen was 40/60 bitumen.

The results of the dynamic shear measurements are shown in Table 5 and Figure

2.

Table 5

Figure 2 shows in particular the following:

• the Young modulus G* of samples 1 - 4 is lower than that of sample 6 which is presumably due to the addition of the rejuveniling resin.

• The Young modulus G* of samples 1 - 4 is similar which indicates that compositions can be made over a wide range of mixing ratios. • At high frequencies (i.e. at low temperatures), the G* modulus of samples 1 - 4 is lower than the G* modulus of sample 7 which indicates that samples 1 - 4 have an improved fatigue resistance.

• At low frequencies (i.e. at high temperatures), the G* modulus of samples 1 - 4 is higher than the G* modulus of sample 7 which indicates that samples 1 - 4 have an improved resistance against deformation and tracking.

The results of the dynamic viscosity measurements are shown in Figure 3. Figure 3 shows in particular the following:

• The viscosities of samples 1 - 4 are lower than the viscosity of sample 5 but higher than the viscosity of 70/100 bitumen (70/100 means a penetration of 70 - 100 x 10 ¹ mm (25 ⁰ C)).

This indicates that for producing asphalt mixtures from roof covering granulates, asphalt granulates, rejuveniling resin and elastomer, a production temperature will be necessary that is about 30 ⁰ C higher than usual (about 170 ⁰ C).

Example 4

Asphalt compositions based on the standard mixture for asphalt concrete 0/8) having high bitumen content (VK2; this standard mixture must contain 6.8 wt.% bitumen) were subjected to the Marshall test.

Composition 1 contained 40/60 bitumen (virgin; penetration according to NEN- EN 1425 (2007) at 25°C of 40 10 ^"1 mm to 60 10 ^"1 mm). Composition 2 contained bitumen from recycled roof covering granulate and 20 wt.% of the additive composition according to the invention (weight ratio rejuveniling resin composition and elastomer is 1 : 1 ; the rejuveniling resin was Rheofalt EM and the elastomer was Kraton® D 1 1 18) . Composition 3 contained the same amount of bitumen as composition 2, provided that the bitumen have been added in the form of roof covering granulate. The Marshall test is an European standard (NEN-EN 12697-23-2003; Bituminous mixtures - Test method for hot mix asphalt - Part 23: Determination of the indirect tensile strength of bituminous specimens) and specifies a test method for determining the stability, flow and the Marshall Quotient values of specimens of bituminous mixtures mixed. The results of the Marshall test are as follows:

Table 6

Compositions 1 and 3 were also tested for tensile strength (kPa) and penetration (10 ¹ mm). The results are shown in Table 7.

Table 7

Example 5

In the Netherlands, recycled asphalt granulate comprises about 4.8 wt.% hardened bitumen and recycled roofing covering granulate comprises about 23 wt.% hardened bitumen. For manufacturing an asphalt sublayer, about 4.5 wt.% bitumen is necessary.

Therefore, a mixture was prepared from about 80 wt.% recycled asphalt granulate (which provides about 3.8 wt.% hardened bitumen), about 4 wt.% roofing covering granulate (which provides about 0.9 wt.% hardened bitumen) and 15 wt.% of the rejuveniling resin Rheofalt EM. No additional elastomer was added. The mixture complied with the requirements according to NEN-EN 13108-20 with respect to stiffness, endurance, deformation and water sensitivity). The test according to NEN-EN 13108-02 is currently used to test virgin bitumen.