Simple application of an adhesive material to a substrate with excellent adhesion to asphalt

Abstract

A method for producing a roadway structure includes: applying pellets of an adhesive composition to a non-tacky surface of a substrate having a support structure, wherein the adhesive composition has at least one solid epoxy resin and at least one thermoplastic polymer that is solid at room temperature; and applying a bitumen-based bearing course. The method permits rapid and efficient production of a roadway structure with good adhesion between the substrate and the asphalt and is suitable in particular for the restoration of asphalt coverings, which must be carried out under time pressure. The application of primer courses is not required.

Claims

1. A method for producing a roadway structure, comprising the steps (i) applying pellets of an adhesive composition to a non-tacky surface of a substrate comprising a support structure, wherein the adhesive composition comprises at least one solid epoxy resin and at least one thermoplastic polymer that is solid at room temperature; and (ii) applying a bitumen-based bearing course.

2. The method according to claim 1, wherein the bitumen-based bearing course is applied to the surface of the substrate provided with the pellets within a period of less than 1 hour after application of the pellets.

3. The method according to claim 1, wherein the pellets are applied by manually or mechanically scattering the pellets onto the surface of the substrate.

4. The method according to claim 1, wherein the pellets have a diameter in a range of from 0.1 to 7 mm.

5. The method according to claim 1, wherein the surface course of the substrate is not a primer course.

6. The method according to claim 1, wherein the amount of pellets applied is in the range of from 10 to 1000 g/m.sup.2.

7. The method according to claim 1, wherein a roadway structure is repaired by the method.

8. The method according to claim 7, wherein the roadway structure to be repaired, which has optionally been pretreated, serves as the substrate for application of the pellets, or an upper portion of the roadway structure to be repaired is removed to form a substrate to which the pellets are applied.

9. The method according to claim 1, wherein the bitumen-based bearing course is applied directly to the pellets applied to the substrate.

10. The method according to claim 1, wherein the non-tacky surface of the substrate is formed of concrete, asphalt, a liquid plastics film or a bitumen membrane.

11. The method according to claim 1, wherein the adhesive composition further comprises a chemical or physical blowing agent based on the weight of the adhesive composition.

12. The method according to claim 1, wherein the at least one thermoplastic polymer that is solid at room temperature comprises an ethylene/vinyl acetate copolymer or a terpolymer of ethylene, acrylic ester and maleic anhydride.

13. A roadway structure obtained by the method according to claim 1.

14. The method according to claim 1, wherein the at least one solid epoxy resin comprises one or more compounds of the following formula: ##STR00002## where R and R are, independently of one another, either H or CH.sub.3, and s is from 2 to 12.

15. The method according to claim 11, wherein the content of the blowing agent in the range of from 0.2 to 2% by weight based on the weight of the adhesive composition.

16. The method according to claim 11, wherein the blowing agent comprises azodicarbonamide.

17. The method according to claim 1, wherein the pellets form an adhesive bond between the non-tacky surface of the substrate and the bitumen-based bearing course.

18. A method comprising: applying pellets of an adhesive composition comprising at least one solid epoxy resin and at least one thermoplastic polymer that is solid at room temperature as an adhesive bonding material between a substrate having a non-tacky surface and a bitumen-based bearing course.

19. The method according to claim 18, wherein the non-tacky surface is a roadway structure in need of repair, the roadway structure having an asphalt covering, and the pellets are applied in an amount effective to repair the roadway structure.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 shows schematically the sequence of courses for the method according to the invention for producing a roadway structure. Only the elements that are essential for the immediate understanding of the invention are shown.

(2) FIG. 1 shows a roadway structure 1 in which pellets of the adhesive composition 3 have been applied to a non-tacky surface of a substrate 2 and a bitumen-based bearing course 4 has been applied thereto. The non-tacky surface of the substrate 2 is preferably concrete or asphalt. The surface of the substrate is, for example, formed by a concrete support structure or an asphalt covering.

LIST OF REFERENCE NUMERALS

(3) 1 Roadway structure 2 Substrate comprising support structure, preferably concrete support structure 3 Pellets of adhesive composition 4 Bitumen-based bearing course

EXAMPLE

(4) An adhesive composition comprising the constituents mentioned in Table 1 in the amounts indicated therein was prepared.

(5) TABLE-US-00001 TABLE 1 Parts by weight EVA Ethylene/vinyl acetate copolymer (vinyl acetate 25.0 content 28% by weight, softening temperature (ring & ball method according to DIN ISO 4625): 106 C.) MAM-EVA Maleic anhydride-grafted ethylene/vinyl 23.4 acetate copolymer (maleic anhydride content: 0.2-0.4% by weight) Araldite Solid epoxy resin 4.0 Hydrocarbon Tackifier resin 10.0 resin Chalk Filler 36.8 Sodium Blowing agent 0.8 bicarbonate

(6) In order to prepare the adhesive composition, the constituents were mixed with one another in a twin-screw extruder at a temperature of 80-120 C. Pellets having a diameter of approximately from 1 to 3 mm were formed by subsequent granulation. The pellets obtained were tested as follows.

(7) A layer of approximately 5 cm was removed from a rolled asphalt (approximately 10 cm thick) by milling.

(8) Conventional bitumen emulsion (0.3 kg/m.sup.2) was then applied to one sample. Pellets of the adhesive composition of Table 1 (0.2 kg/m.sup.2) were applied to a second sample.

(9) A layer of rolled asphalt was then applied to each of the two samples (5 cm, 160 C.).

(10) The bond between the layers is determined in accordance with ZTV Asphalt-StB 07 (norm: >15 kN).

(11) The use of 0.3 kg/m.sup.2 of bitumen emulsion in accordance with the prior art leads to a tensile adhesion value of 30 kN in respect of the layer combination asphalt/asphalt used.

(12) The use of 0.2 kg/m.sup.2 of pellets of the adhesive composition of Table 1 leads in the case according to the invention to a measured value of >50 kN for the layer combination asphalt/asphalt. The amount of adhesive composition used can consequently be reduced further in order to achieve the same tensile adhesion value as is achieved according to the prior art with bitumen emulsion. This results in a considerable cost reduction.