PRESTRESSED CONCRETE BODY, METHOD FOR THE PRODUCTION THEREOF, AND USE OF SAME

Abstract

The invention relates to a prestressed concrete body, containing prestressed filament yarns based on cellulose and/or cellulose derivatives. Advantageously, said prestressed concrete body is produced in that: 1.) filament yarns based on cellulose and/or derivatives thereof are clamped into a shaping container, 2.) the clamped filament yarns are wetted with water to make them swell, 3.) a prestress of approximately 0.5 to 10.0 kg/4000 dtex is applied to the wetted filament yarns, 4.) liquid concrete is poured into the shaping container containing the prestressed filament yarns, 5.) the liquid concrete in the shaping container is cured to form precast concrete, maintaining the specified applied prestress. Useful application possibilities are opened up by the invention. Use as components or structural elements with low brittleness and/or high resistance to corrosion, especially in bridge building, especially in bridge girders, in constructing containers, in constructing high-rise structures, in the production of hollow floors or ceilings, hollow core planks, precast floors or ceilings and for recycling once the service life has passed by being ground into concrete granules is advantageous.

Claims

1-11. (canceled)

12. A method for producing a prestressed concrete body according to at least one of the preceding claims, characterised in that) 1. filament yarns based on cellulose and/or derivatives thereof are clamped into a shaping container, 2.) the clamped filament yarns are wetted with water to make them swell, 3.) a prestress of approximately 0.5 to 10.0 kg/4000 dtex is applied to the wetted filament yarns, 4.) liquid concrete is poured into the shaping container containing the prestressed filament yarns, 5.) the liquid concrete in the shaping container is cured to form precast concrete, maintaining the specified applied prestress.

13-20. (canceled)

21. A method for producing a prestressed concrete body, characterised in that 1. filament yarns based on cellulose and/or derivatives thereof are clamped into a shaping container, 2.) the clamped filament yarns are wetted with water to make them swell, 3.) a prestress of approximately 0.5 to 10.0 kg/4000 dtex is applied to the wetted filament yarns, 4.) liquid concrete is poured into the shaping container containing the prestressed filament yarns, 5.) the liquid concrete in the shaping container is cured to form precast concrete, maintaining the specified applied prestress.

22. The method according to claim 21, characterised in that the prestress in step 3.) is set to approximately 1.0 kg to 8.0 kg/4000 dtex.

23. The method according to claim 21, characterised in that the fineness of the individual filaments of the prestressed and of the optionally non-prestressed filament yarns is approximately 0.4 to 10.0 dtex.

24. The method according to claim 21, characterised in that the prestressed filament yarns are contained in the liquid concrete introduced in step 4.) in an amount of approximately 0.1 to approximately 20 wt %.

25. The method according to claim 21, characterised in that in addition to the prestressed filament yarns, non-prestressed filament yarns are incorporated into the method, especially before step 4.).

26. The method according to claim 25, characterised in that the yarns are textiles present in the form of woven fabrics, warp-knitted fabrics, laid scrims, nonwoven fabrics and/or weft-knitted fabrics.

27. The method according to claim 25, characterised in that regenerated cellulose yarns produced by the viscose or the lyocell method or by spinning of cellulose from ionic liquids, are used as filament yarns for providing prestressed filament yarns in the prestressed concrete.

28. The method according to claim 27, characterised in that the filament yarns are based on viscose fibres, especially on cord fibres.

29. A prestressed concrete body, obtainable by the method according to claim 25 and characterised in that the prestressed concrete body contains prestressed filament yarns based on cellulose and/or cellulose derivatives.

30. The prestressed concrete body according to claim 29, characterised in that the prestressed concrete body contains approximately 0.1 to 20 wt. % prestressed filament yarns.

31. The prestressed concrete body according to claim 29, characterised in that the prestressed concrete body additionally contains non-prestressed filament yarns.

32. The prestressed concrete body according to claim 31, characterised in that the textiles are present in the form of woven fabrics, warp-knitted fabrics, laid scrims, nonwoven fabrics and/or weft-knitted fabrics.

33. The prestressed concrete body according to claim 29, characterised in that the prestressed filament yarns are based on regenerated cellulose fibres produced by the viscose or the lyocell method or by spinning cellulose from solution thereof in ionic liquids.

34. The prestressed concrete body according to claim 33, characterised in that the prestressed filament yarns are based on viscose fibres in the form of cord fibres.

35. The prestressed concrete body according to claim 29, characterised in that the prestressed concrete body contains prestressed filament yarns based on cellulose derivatives in the form of cellulose esters cellulose acetate and/or cellulose allophanate.

36. The prestressed concrete body according to claim 29, characterised in that the filament yarns are arranged in parallel in one or more planes.

37. The prestressed concrete body according to claim 29, characterised in that the prestressed concrete body has a flexural modulus of approximately 20 GPa to 0.1 GPa (according to DIN EN 14488/year 2005), a bending force of approximately 100 to 0.2 (according to DIN EN 14488/year 2005), and/or an elongation at break of approximately 5 to 0.5 (according to DIN EN 14488/year 2005).

38. A component or structural element with low brittleness and/or high resistance to corrosion, especially in bridge building, in constructing containers, in constructing high-rise structures, in the production of hollow floors or ceilings, precast floors or ceilings and for recycling once the service life has passed by being ground into concrete granules, said component or structured element being compound of the prestressed concrete of claim 29.

39. The method according to claim 21, characterised in that the prestress in step 3.) is set to approximately 2.0 kg to 6.0 kg dtex; the individual filaments of the prestressed and of the optionally non-prestressed filament yarns is approximately 1.0 to 3.0 dtex; the prestressed filament yarns are contained in the liquid concrete introduced in step 4.) in an amount of approximately 1.0 to 6.0 wt. %; the prestressed concrete body contains approximately 1.0 to 6.0 wt. % prestressed filament yarns; and the prestressed concrete body contains prestressed filament yarns based on cellulose acetate and/or cellulose allophanate.

Description

EXAMPLES 1 TO 4

[0026] Regenerated cellulose yarns (manufactured and distributed by Cordenka GmbH) type Cordenka 700 (1840 dtex) are threaded into an aperture of a cement mould of size 15×6×3 cm in several rows and stressed with a tensile load of 1 kg/4000 dtex. The fibres are sprayed with water and stretched. Portland limestone cement (produced by the company Heidelberger Zement) EN 197 is mixed in a ratio of 1 part cement/0.4 parts water according to the instructions. The mass is poured evenly into the mould. The cast specimen is cured and dried at 20° C. for 28 days. The sample can be removed from the mould after 28 days drying time. The mechanical measurement was carried out on a Zwick tester according to DIN EN 14488.

TABLE-US-00001 TABLE 1 Fibre Flexural Bending Elongation at content modulus force break Example [wt. %] [MPa] [MPa] [%] 1 0 718 2.10 0.5 2 0.2 730 2.5 0.7 3 0.6 820 3.1 0.9 4 1 1200 4.2 1.1

EXAMPLES 5 AND 6

[0027] Embodiment as per Examples 1-4 without tensile load

TABLE-US-00002 TABLE 2 Fibre Flexural Bending Elongation at content modulus force break Example [wt. %] [MPa] [MPa] [%] 5 0.2 718 2.3 0.6 6 1 740 2.7 0.9

EXAMPLE 7

[0028] Embodiment as per Examples 1-4. In addition, a woven fabric in plain weave, produced from regenerated cellulose yarns Cordenka 700 (1840 dtex), is inserted into the mould. Weight per unit area 400 g/m.sup.2.

TABLE-US-00003 TABLE 3 Fibre Flexural Bending Elongation at content modulus force break Example [wt. %] [MPa] [MPa] [%] 7 1 + Woven 1350 4.6 1.1 fabric