DRY MORTAR, MORTAR SLURRY AND METHOD FOR PRODUCING SEMI-RIGID COATINGS

Abstract

The present invention relates to a dry mortar and a mortar slurry as well as a method for producing semi-rigid coatings. In one embodiment, the dry mortar or the mortar slurry contains a cement, a very fine component and a plasticizer and is free from silica fume, wherein the mortar slurry can be applied at a temperature of the asphalt support structure of 55 to 80 C. and a compressive strength of at least 100 N/mm.sup.2 is achieved after 28 days. In a further embodiment, the dry mortar or the mortar slurry also contains a gelling agent such that the mortar slurry has a reduced efflux tendency.

Claims

1-15. (canceled)

16. Dry mortar comprising cement and a very fine component which is able to be mixed to form a mortar slurry, wherein no silica fume is contained and the dry mortar contains at least one plasticizer and/or at least one plasticizer is contained in the water or is added during mixing with water, wherein at least 62% by weight cement is contained and the compressive strength of the mortar slurry is at least 100 N/mm.sup.2 after 28 days.

17. Dry mortar according to claim 16, wherein at least 88% by weight cement is contained.

18. Dry mortar according to claim 16, wherein no aggregate is contained.

19. Dry mortar according to claim 16, wherein a gelling agent is contained.

20. Dry mortar according to claim 19, wherein the gelling agent is selected from the group consisting of clay, pyrogenic silica, highly dispersed silica, biopolymers and mixtures of two or more of these.

21. Dry mortar according to claim 19, wherein the gelling agent is contained in a quantity in the range from 0.001 to 1% by weight based on a dry substance of the dry mortar.

22. Dry mortar according to claim 16, wherein the dry mortar contains one or more plasticising admixtures.

23. Dry mortar according to claim 16, wherein the plasticising admixture/admixtures is/are contained in a quantity in the range from 0.5 to 5% by weight based on a dry substance of the mortar.

24. Dry mortar according to claim 16, wherein the cement is selected from the group consisting of Portland cement and Portland cement mixed with latent hydraulic and/or pozzolanic materials.

25. Dry mortar according to claim 16, wherein the dry mortar contains inert filling materials.

26. Dry mortar according to claim 16, wherein one or more retarder(s) is/are contained.

27. Mortar slurry obtainable by mixing a dry mortar with water, wherein the dry mortar comprises at least 62% by weight cement and a very fine component, wherein no silica fume is contained and wherein the dry mortar contains at least one plasticizer and/or at least one plasticizer is contained in the water or is added during mixing with water and wherein the compressive strength of the mortar slurry is at least 100 N/mm.sup.2 after 28 days.

28. Mortar slurry according to claim 27, wherein only the dry mortar and water are contained.

29. Method for producing a semi-rigid coating on a support layer, comprising the steps applying an asphalt support structure with a void content in the range from 10 to 40% by volume preparing a mortar slurry from a dry mortar comprising 62 to 99.5% by weight cement and a very fine component by mixing the dry mortar with water to form the mortar slurry, wherein no silica fume is contained in the mortar slurry and the dry mortar contains at least one plasticizer and/or at least one plasticizer is contained in the water or is added with the water, wherein the mortar slurry is applied at a temperature of the asphalt support structure of 55 to 80 C.

30. Method for producing a semi-rigid coating on a sloping support layer, comprising the steps applying an asphalt support structure with a void content in the range from 10 to 40% by volume preparing a mortar slurry from a dry mortar comprising 62 to 99.5% by weight cement, a very fine component and a gelling agent by mixing the dry mortar with water to form the mortar slurry, wherein no silica fume is contained in the mortar slurry and the dry mortar contains at least one plasticizer and/or at least one plasticizer is contained in the water or is added with the water, and applying the mortar slurry at a temperature of the asphalt support structure of 55 to 60 C.

31. Dry mortar according to claim 20, wherein the gelling agent is contained in a quantity in the range from 0.005 to 0.25% by weight based on a dry substance of the dry mortar.

32. Dry mortar according to claim 22, wherein the plasticising admixture(s) is(are) selected from the group consisting of plasticizers based on lignosulphonates, melamine resins, (poly)naphthalene sulphonates, substances or substance mixtures referred to as polycarboxylate ethers (PCE), acrylic-based substances or substance mixtures, vinyl-based substances or substance mixtures, carboxylic acid-based substances or substance mixtures as well as their derivatives, and mixtures of two or more thereof.

33. Dry mortar according to claim 32, wherein the plasticising admixture(s) is(are) contained in a quantity in the range from 0.6 to 1% by weight.

34. Dry mortar according to claim 25, wherein the inert filling material is limestone powder.

35. Dry mortar according to claim 26, wherein the one or more retarder(s) is(are) gluconates and/or phosphate/sucrose.

36. Dry mortar according to claim 35, wherein at least 88% by weight cement is contained.

37. Dry mortar according to claim 33, wherein an inert filling material being limestone powder is contained.

38. Mortar slurry according to claim 27, wherein the plasticising admixture(s) is(are) selected from the group consisting of plasticizers based on lignosulphonates, melamine resins, (poly)naphthalene sulphonates, substances or substance mixtures referred to as polycarboxylate ethers (PCE), acrylic-based substances or substance mixtures, vinyl-based substances or substance mixtures, carboxylic acid-based substances or substance mixtures as well as their derivatives, and mixtures of two or more thereof.

39. Mortar slurry according to claim 38, wherein at least 88% by weight cement is contained.

40. Mortar slurry according to claim 38, wherein an inert filling material being limestone powder is contained.

41. Mortar slurry according to claim 28, wherein the plasticising admixture(s) is(are) selected from the group consisting of plasticizers based on lignosulphonates, melamine resins, (poly)naphthalene sulphonates, substances or substance mixtures referred to as polycarboxylate ethers (PCE), acrylic-based substances or substance mixtures, vinyl-based substances or substance mixtures, carboxylic acid-based substances or substance mixtures as well as their derivatives, and mixtures of two or more thereof.

42. Mortar slurry according to claim 41, wherein at least 88% by weight cement is contained.

Description

EXAMPLES

[0034] For the examples, the following substances were used: [0035] Cement: CEM I 52.5 R [0036] Mineral: inert mineral filler from the substance group alkaline earth carbonates, density 2.60g/cm.sup.3, particle size 0.1 mm [0037] Plasticizer A: modified polycarboxylate ether [0038] Plasticizer B: modified polycarboxylate ether [0039] Gelling agent A: Clays with the main minerals: Kaolinite, illite, montmorillonite [0040] Gelling agent B: Biopolymers [0041] Gelling agent C: Hydrophilic pyrogenic silica [0042] Retarder: phosphate/sucrose mixture [0043] Mortar slurries are produced from the components specified in Tables 3 and 4 in the stated quantities in % by weight based on the dry substance with the addition of water at the specified ratio. The properties of the fresh mortar and the hardened mortar were respectively determined according to the method already stated above and are specified in Tables 5 and 6.

[0044] Furthermore, the efflux tendency of the mortar slurries is determined by means of a specifically developed device and method. The device is a container, for example a box, divided into two chambers. An asphalt support structure is installed in one region of the container, said support structure preferably corresponding to that which is to be filled with the mortar slurry to be tested. The chambers are divided at the start of the test with a slide and a seal on the asphalt side. At least such a quantity of mortar slurry, that is enough to fill the asphalt support structure, is added to the chamber prepared with asphalt. After a selected time period has passed, for example one hour, the slide is pulled up and the seal is removed. It is visually evaluated how far the mortar slurry flows out from the asphalt support structure if no additional shear energy is supplied to the system. The results are recorded in Table 5. The indication yes for retention means that no significant quantity of slurry flowed out, no means the flowing out of a larger quantity, which makes refilling voids necessary.

TABLE-US-00003 TABLE 3 Compositions of temperature-stable mortar slurry MS 1 MS 2 MS 3 MS 4 MS 5 MS 6 Cement 99.25 99.25 99.0 99.0 99.23 89.25 Mineral 10 Plasticizer A 0.75 0.75 1.0 0.75 0.75 Plasticizer B 1.0 Retarder 0.02 Dry substance: 1:0.29 1:0.31 1:0.29 1:0.29 1:0.30 1:0.29 Water

TABLE-US-00004 TABLE 4 Compositions of thixotropic mortar slurry MS 7 MS 8 MS 9 Cement 89.00 88.85 89.24 Mineral 10.00 10.00 10.00 Plasticizer A 0.65 0.65 0.75 Gelling agent A 0.35 Gelling agent B 0.50 Gelling agent C 0.01 Dry substance:Water 1:0.30 1:0.29 1:0.30

TABLE-US-00005 TABLE 5 Test results temperature-stable mortar slurry Property Time MS 1 MS 2 MS 3 MS 4 MS 5 MS 6 Efflux time after 20 s 19 s 27 s 30 s 16 s 22 s mixing after 1 h 48 s 37 s 42 s 53 s 33 s 52 s Compressive 24 h 97.2 56.8 57.7 53.3 83.0 59.1 strength in 3 d 104.7 78.2 78.6 74.9 82.2 73.8. N/mm.sup.2 28 d 143.8 106.9 104.6 103.4 101.9 102.0 Bending tensile 24 h >15 6.5 12.6 9.7 10.5 9.8 strength in 3 d >15 11.2 >15 14.3 11.7 13.0 N/mm.sup.2 28 d >15 14.2 >15 <15 13.0 12.8

TABLE-US-00006 TABLE 6 Test results thixotropic mortar slurry Property Time MS 7 MS 8 MS 9 Efflux time after mixing 42 s 43 s 40 s after 1 h 54 s 44 s 44 s Compressive 24 h 64.2 61.0 56.5 strength 3 d 84.1 76.9 68.8 in N/mm.sup.2 28 d 116.7 107.1 106.1 Bending tensile 24 h 7.1 10.4 7.3 strength 3 d 12.6 10.0 12.7 in N/mm.sup.2 28 d 13.2 13.4 14.1 Retention after 1 h yes yes yes

[0045] It is clear from the measurement results in Tables 5 and 6 that the mortar slurries according to the invention solve the objects. The properties of the mortar slurries correspond to the requirements of the guidelines with respect to the processing properties of fresh mortar and the mechanical properties of hardened mortar.

[0046] As was confirmed by means of sample cross sections, the temperature-stable mortar slurry fills the voids reliably and completely even with 80 C. hot asphalt. In FIG. 1, a cross section is shown for the mortar slurry 1 introduced at 80 C. asphalt temperature. In comparison, FIG. 2 shows the result when using a mortar slurry made from a commercially obtainable dry mortar containing silica fume. It is clear to see that the comparison mortar slurry applied at 80 C. can barely enter the asphalt support structure; useful coatings are therefore not obtained.

[0047] The thixotropic mortar slurry can also fill the voids reliably and completely at 60 C. and lower. It thereby shows a highly reduced flow after just a short time. In FIG. 3, the results of the described, newly developed method for the mortar slurry 1 as reference and mortar slurry 9 are shown. It is good to recognise that the mortar slurry 1 without gelling agent flows out of the support structure over a large area, whereas no flowing out is apparent for the mortar slurry 9 with gelling agent.

[0048] The semi-rigid coatings described are suitable for cover layers on particularly stressed traffic areas such as, for example, support surfaces for heavy goods vehicles, bus traffic areas, areas before signalling systems, industrial spaces such as, for example, container terminals, harbours/docks, airfields and warehouse floors. The system can also be used in the scope of refuelling systems and for storage, filling and handling areas for water-polluting substances. The system is applied to a base made from asphalt or a hydraulically bound support layer. It can be used in new constructions and in renovations or strengthening of buildings. A significant amount of time can thereby be saved during installation. For the thixotropic mortar slurries, there is a higher fault tolerance regarding leaking asphalt support structures and a facilitated and quicker installation for sloped roads. It also seems to be possible to provide roads having a larger slope than before with the semi-rigid coating.