Dry Cement Mixture

Abstract

A dry cement mixture comprises Portland cement and an ultra-fine component consisting of at least one ultra-fine additive, said ultra-fine component being a hydraulic binder, wherein Portland cement is present in an amount of at least 70 wt % of the mixture and the ultra-fine component is present in an amount of at least 5 wt % of the mixture, wherein the ultra-fine component has a particle size distribution characterized by a particle diameter D.sub.10 of between 0.5 m and 2 m and a particle diameter D.sub.90 of between 2 m and 8 m.

Claims

1-13. (canceled)

14. A dry cement mixture comprising (a) Portland cement; and (b) an ultra-fine component consisting of at least one ultra-fine additive, said ultra-fine component being a hydraulic binder, wherein the dry cement mixture comprises at least 70 wt % Portland cement of the dry cement mixture, and at least 5 wt % of the ultra-fine component of the dry cement mixture, the ultra-fine component has a particle size distribution characterized by a particle diameter D.sub.10 of between 0.5 m and 2 m and a particle diameter D.sub.90 between 2 m and 8 m, and the at least one ultra-fine additive comprises slag in an amount of (i) >70 wt % or (ii) >80 wt %.

15. The dry cement mixture according to claim 14, wherein the Portland cement is present in an amount of (i) at least 80 wt % or (ii) at least 85 wt % of the dry cement mixture.

16. The dry cement mixture according to claim 14, wherein Portland cement is present in an amount of 70-79 wt % of the dry cement mixture.

17. The dry cement mixture according to claim 14, wherein the Portland cement is present in an amount of (i) at least 85 wt % or (ii) at least 90 wt % of the dry cement mixture; and the ultra-fine component is present in an amount of (i) at least 7 wt % or (ii) at least 10 wt % of the dry cement mixture.

18. The dry cement mixture according to claim 14, wherein the weight ratio of Portland cement and the ultra-fine hydraulic component is (i) between 85/15 and 95/5 or (ii) about 90/10.

19. The dry cement mixture according to claim 14, wherein the ultra-fine component has a particle size distribution characterized by a particle diameter D.sub.10 of between 0.7 m and 1 m.

20. The dry cement mixture according to claim 14, wherein the ultra-fine component has a particle size distribution characterized by a particle diameter D.sub.90 of between 4 m and 6 m.

21. The dry cement mixture according to claim 14, wherein the ultra-fine component has a particle size distribution characterized by a particle diameter D.sub.100 of (i) 10 m-15 m, or (ii) 12 m.

22. The dry cement mixture according to claim 14, wherein the Portland cement has a particle size distribution characterized by a particle diameter D.sub.10 of (i) between 1 m and 3 m, (ii) between 1.6 m and 2 m, or (iii) 1.8 m; and a particle diameter D.sub.90 of between (i) 30 m and 60 m, (ii) between 35 and 45 m, or (iii) 40 m.

23. The dry cement mixture according to claim 14, wherein the Portland cement is a CEM I cement according to EN 197-1.

24. The dry cement mixture according to claim 14, wherein the slag comprises ground blast furnace slag.

25. The dry cement according to claim 14, wherein the ultra-fine component has a particle size distribution characterized by a particle diameter D.sub.10 of between 0.7 m and 1 m, a particle diameter D.sub.90 of between 4 m and 12 m, and a particle size distribution characterized by a particle diameter D.sub.100 of (i) 10 m-15 m, or (ii) 12 m; the Portland cement has a particle size distribution characterized by a particle diameter D.sub.10 of (i) between 1 m and 3 m, (ii) between 1.6 m and 2 m, or (iii) 108 m, and a particle diameter D.sub.90 of between (i) 30 m 60 m, (ii) between 35 and 45 m, or (iii) 40 m; and the weight ratio of Portland cement to the ultra-fine hydraulic component is (i) between 85/15 and 95/5 or (ii) about 90/10.

26. A concrete composition comprising (a) a cement mixture according to claim 14; (b) aggregates; and (c) water.

27. A construction element comprising concrete produced using a concrete composition according to claim 26.

Description

EXAMPLE 1

[0027] A dry cement mixture with the following components was produced. [0028] 90 wt % of Portland cement of the type CEM I 52.5 N [0029] 10 wt % of an ultra-fine blast furnace slag binder.

[0030] Portland cement having the following particle size distribution was used: D.sub.10=1.8 m and D.sub.90=ca. 40 m Ultra-fine blast furnace slag binder having the following particle size distribution was used: D.sub.10=ca. 0.8 m and D.sub.90=ca. 5.5 m

[0031] The resulting mixture had the following composition: [0032] Clinker: 86.06 wt % [0033] Blast furnace slag: 7.8 wt % [0034] Gypsum: 5.6 wt % [0035] Anhydrite: 0.3 wt % [0036] Dust: 0.2 wt % [0037] NaCl: 0.04 wt %

EXAMPLE 2

[0038] Concrete was produced form the dry cement mixture as described in example 1. The following components were mixed in a mixer: [0039] 410 kg of dry cement mixture as described in example 1 [0040] 907 kg of aggregates with a nominal maximum coarse diameter of 12.5 mm [0041] 797 kg of sand with a nominal maximum coarse diameter of 4 mm [0042] 90 kg of limestone filler [0043] Superplasticizer admixture in the amount of 1.2 wt % of the dry cement mixture [0044] 160 l of water

[0045] The wet concrete mass was poured into a form and cured to obtain a concrete block having the following mechanical strength values:

[0046] Compressive strength: [0047] 1 day: 39 MPa [0048] 7 days: 76 MPa [0049] 28 days: 89 MPa

[0050] Flexural strength: [0051] 28 days: 6 MPa

[0052] Young modulus: [0053] 28 days: 44 GPa

EXAMPLE 3

[0054] Concrete was produced form the dry cement mixture as described in example 1. The following components were mixed in a mixer: [0055] 450 kg of dry cement mixture as described in example 1 [0056] 930 kg of aggregates with a nominal maximum coarse diameter of 12.5 mm [0057] 790 kg of sand with a nominal maximum coarse diameter of 4 mm [0058] 80 kg of limestone filler [0059] Superplasticizer admixture in the amount of 2.0 wt % of the dry cement mixture [0060] 148 l of water

[0061] The wet concrete mass was poured into a form and cured to obtain a concrete block having the following mechanical strength values:

[0062] Compressive strength: [0063] 1 day: 49 MPa [0064] 7 days: 81 MPa [0065] 28 days: 94 MPa

[0066] Flexural strength: [0067] 28 days: 6 MPa

[0068] Young modulus: [0069] 28 days: 43 GPa

EXAMPLE 4

[0070] A comparative study was carried out between concretes composed respectively of: [0071] A/ C50/60 with ordinary Portland cement [0072] B/ C50/60 with dry cement mixture with an optimized dosage [0073] C/ C60/75 with ordinary Portland cement and silica fume addition [0074] D/ C60/75 with dry cement mixture

[0075] The denominations C50/60 and C65/70 refer to the strength class according to Eurocode 2 (European Standard EN 1992). For example, C50/60 means that the concrete must have a compressive cylinder strength of 50 N/mm.sup.2 and a cube compressive strength of 60 N/mm.sup.2.

[0076] A/ C50/60 with Ordinary Portland Cement: [0077] 425 kg of ordinary Portland cement [0078] 315 kg of aggregates with a nominal maximum coarse diameter of 12 mm [0079] 670 kg of aggregates with a nominal maximum coarse diameter of 20 mm [0080] 730 kg of sand with a nominal maximum coarse diameter of 4 mm [0081] Superplasticizer admixture in the amount of 1.3 wt % of the dry cement mixture [0082] 175 l of water

[0083] The wet concrete mass was poured into a form and cured to obtain a concrete block having the following mechanical strength values:

[0084] Compressive strength: [0085] 1 day: 12 MPa [0086] 7 days: 47 MPa [0087] 28 days: 56 MPa [0088] 90 days: 57 MPa

[0089] Abrasion resistance coefficient (following the Compagnie Nationale du Rhne protocol): [0090] C=0.5

[0091] Shock resistance (following the Compagnie Nationale du Rhne protocol): [0092] Volume caused by impacts=108 cm.sup.3

[0093] The concrete block showed the following characteristics in terms of durability: [0094] Internal porosity: 12.6% [0095] Gas permeability: 119 E18 m.sup.2

[0096] Chloride diffusion coefficient (migration test in stationary electric field): 6.8 E12 m.sup.2/s

[0097] B/ C50/60 with Dry Cement Mixture with an Optimized Dosage [0098] 390 kg of dry cement mixture as described in example 1 [0099] 315 kg of aggregates with a nominal maximum coarse diameter of 12 mm [0100] 670 kg of aggregates with a nominal maximum coarse diameter of 20 mm [0101] 765 kg of sand with a nominal maximum coarse diameter of 4 mm [0102] Superplasticizer admixture in the amount of 1.2 wt % of the dry cement mixture [0103] 180 l of water

[0104] The wet concrete mass was poured into a form and cured to obtain a concrete block having the following mechanical strength values:

[0105] Compressive strength: [0106] 1 day: 9 MPa [0107] 7 days: 44 MPa [0108] 28 days: 53 MPa [0109] 90 days: 57 MPa

[0110] Abrasion resistance coefficient (following the Compagnie Nationale du Rhne protocol): [0111] C=0.5

[0112] Shock resistance (following the Compagnie Nationale du Rhne protocol): [0113] Volume caused by impacts=118 cm.sup.3

[0114] The concrete block showed the following characteristics in terms of durability: [0115] Internal porosity: 13% [0116] Gas permeability: 76 E18 m.sup.2 [0117] Chloride diffusion coefficient (migration test in stationary electric field): 8.0 E12 m.sup.2/s

[0118] C/ C60/75 with Ordinary Portland Cement+Silica Fume Addition: [0119] 415 kg of ordinary Portland cement [0120] 270 kg of aggregates with a nominal maximum coarse diameter of 12 mm [0121] 700 kg of aggregates with a nominal maximum coarse diameter of 20 mm [0122] 800 kg of sand with a nominal maximum coarse diameter of 4 mm [0123] 25 kg of silica fume addition [0124] Superplasticizer admixture in the amount of 1.8 wt % of the dry cement mixture [0125] 161 l of water

[0126] The wet concrete mass was poured into a form and cured to obtain a concrete block having the following mechanical strength values:

[0127] Compressive strength: [0128] 1 day: 22 MPa [0129] 7 days: 56 MPa [0130] 28 days: 70 MPa [0131] 90 days: 75 MPa

[0132] Abrasion resistance coefficient (following the Compagnie Nationale du Rhne protocol): [0133] C=0.3

[0134] Shock resistance (following the Compagnie Nationale du Rhne protocol): [0135] Volume caused by impacts=103 cm.sup.3

[0136] The concrete block showed the following characteristics in terms of durability: [0137] Internal porosity: 11.8 % [0138] Gas permeability: 40 E18 m.sup.2

[0139] Chloride diffusion coefficient (migration test in stationary electric field): 0.4 E12 m.sup.2/s

[0140] D/ C60/75 with Dry Cement Mixture: [0141] 440 kg of dry cement mixture as described in example 1 [0142] 270 kg of aggregates with a nominal maximum coarse diameter of 12 mm [0143] 700 kg of aggregates with a nominal maximum coarse diameter of 20 mm [0144] 800 kg of sand with a nominal maximum coarse diameter of 4 mm [0145] Superplasticizer admixture in the amount of 1.8 wt % of the dry cement mixture [0146] 147 l of water

[0147] The wet concrete mass was poured into a form and cured to obtain a concrete block having the following mechanical strength values:

[0148] Compressive strength: [0149] 1 day: 15 MPa [0150] 7 days: 63 MPa [0151] 28 days: 74 MPa [0152] 90 days: 75 MPa

[0153] Abrasion resistance coefficient (following the Compagnie Nationale du Rhne protocol): [0154] C=0.3

[0155] Shock resistance (following the Compagnie Nationale du Rhne protocol): [0156] Volume caused by impacts=91 cm.sup.3

[0157] The concrete block showed the following characteristics in terms of durability: [0158] Internal porosity: 8.9% [0159] Gas permeability: 72 E18 m.sup.2 [0160] Chloride diffusion coefficient (migration test in stationary electric field): 2.2 E12 m.sup.2/s

[0161] This study shows that the performance of the dry cement mixture of the invention enables to decrease the amount of binder in concrete without affecting its mechanical strength development and its durability. It also performs as well as mixtures composed of ordinary Portland cement and ultrafine high performance costly additions such as silica fume, from both a mechanical and a durability point of view. The dry cement mixture of the invention allows the production of high performance concrete in an easy way, and at an optimized cost.