METHOD FOR PRODUCING AN INSULATING COMPOSITE BUILDING BLOCK

Abstract

A method for producing an insulating composite block including a mineral foam, includes: providing a block including at least one cell having walls which are either sufficiently humid or consist of a water-repellent material, and b. filling the cell with a mineral foam that does not substantially include any calcium aluminate.

Claims

1. A method for producing a composite insulating mineral block, comprising the following steps: a) providing a mineral masonry block comprising at least one cell with walls having a water absorption rate of less than 5 g/(m.sup.2.Math.s) at 10 minutes, and b) filling said cell with a mineral cement foam substantially not comprising any calcium aluminate cement.

2. The method according to claim 1, wherein the block used at step a) is in a fresh state or sufficiently wet.

3. The method according to claim 1, wherein the mineral cement foam does not substantially comprise any quick-setting cement.

4. The method according to claim 1, wherein the mineral cement foam has a density of less than 600 kg/m.sup.3.

5. The method according to claim 1, wherein the mineral cement foam used at step b) has thermal conductivity ranging from 0.03 to 0.06 W/m.Math.K.

6. The method according to claim 1, wherein said cell is a through cell.

7. The method according to claim 1, wherein the block is a concrete block.

8. The method according to claim 1, wherein a time lapse between steps a) and b) does not exceed 60 minutes.

9. The method according to claim 1, further comprising a step for applying a water repellent compound to the cell walls of the block, a preliminary step before filling step b).

10. The method according claim 1, wherein the block used at step a) comprises a water repellent compound mixed in the bulk of the block.

11. The method according to claim 1, wherein the method is performed without carrying out a drying or oven baking step of the block before steps a) or b).

12. The method according to claim 1, wherein the method is a continuous or semi-continuous method.

13. A composite insulating mineral block obtained by the method according to claim 1.

14. A method comprising utilizing a composite insulating mineral block according to claim 13, for building.

15. The method according to claim 8, wherein the time lapse between steps a) and b) does not exceed 30 minutes.

16. The method according to claim 14, wherein the composite insulating mineral block is utilized for masonry.

Description

[0075] The invention will be better understood on reading the appended examples and Figures which are in no way limiting and in which:

[0076] FIG. 1 illustrates concrete blocks filled with a cement foam according to the invention;

[0077] FIG. 2 illustrates part of the concrete block in FIG. 1 after drying; and

[0078] FIG. 3 is a comparative example of a concrete block when the method of the invention is not applied.

EXAMPLES

Forming of Concrete Blocks with Cells

[0079] A standard concrete was obtained using following formula F33:

Hydraulic Binders:

[0080] 4.952 Kg of cement of type CEM I, or Portland type cement, comprising more than 95% of clinker (conforming to standard NF EN 197-1) sold by Lafarge under the trade name Ciment 52.5R;

[0081] 2.476 Kg of limestone material (slag) sold under the trade name BL200 by Orgon, Omya group.

Aggregate:

[0082] 24.514 Kg of sand from Petite Craz quarry of ground particle size 0/4 mm (as per standard BS EN 13139) sold by Lafarge aggregates under the trade name 0/4C.

[0083] 29.962 Kg of gravel from Petite Craz quarry of ground particle size 4/6.3 mm (as per standard BS EN 13139) sold by Lafarge aggregate under the trade name 4/6.3C.

[0084] The amount of pre-wetting water was 2.179 kg and the amount of mixing water was 0.916 kg.

A waterproofed concrete was obtained using following formula F 34:

Hydraulic Binders:

[0085] 4.943 Kg of cement of CEM I type, or cement of Portland type, comprising more than 95% clinker (conforming to standard NF EN 197-1) sold by Lafarge under the trade name Ciment 52.5R;

[0086] 2.471 Kg of limestone material (slag) sold under the trade name BL200 by Orgon, Omya group.

Aggregates:

[0087] 24.468 Kg of sand from Petite Craz quarry of particle size 0/4 mm (conforming to standard BS EN 13139) sold by Lafarge aggregates under the trade name 0/4C.

[0088] 29.905 Kg of gravel from Petite Craz quarry of particle size 4/6.3 mm (conforming to standard BS EN 13139) sold by Lafarge aggregates under the trade name 4/6.3C.

[0089] 0.099 kg of water repelling agent CHRYSOFUGE C produced by Chryso.

[0090] The amount of pre-wetting water was 2.175 kg and the amount of mixing water 1.038 kg.

[0091] A standard lightweight concrete was obtained using following formula F41:

[0092] Hydraulic Binders: [0093] 4.943 Kg of cement of CEM I type, or cement of Portland type, comprising more than 95% clinker (conforming to standard NF EN 197-1) sold by Lafarge under the trade name Ciment 52.5R.

[0094] Aggregates: [0095] 39.377 Kg of pumice stone sand of particle size 0/6 mm sold by Lafarge aggregates under the trade name Ponce de lava GR3554. [0096] The amount of mixing water was 2.701 kg.

[0097] Concrete Preparation:

[0098] The method to obtain the concrete in the examples below followed a standard protocol as follows: [0099] Loading the aggregates in the mixer. [0100] Homogenisation for 30 s. [0101] Adding pre-wetting water in 30 s (4% by weight of the aggregates). [0102] Mixing for 1 min. [0103] Leaving the mix to stand for 4 min (time needed to reach absorption equilibrium of the aggregates). [0104] Adding the binders. [0105] Mixing for 1 min. [0106] Adding the mixing water in 30 s. [0107] Mixing for 1 min 30 s. [0108] Collection.

[0109] Homogenisation and mixing were performed using a standard mixer having the following technical characteristics: vertical axis mixer with eccentric blades, rotating drum, Zylos brand.

[0110] For lightweight concrete, the preparation method in the example below was performed following a standard protocol as follows: [0111] Loading the aggregates and binders in a mixer. [0112] Mixing for 1 min. [0113] Adding the mixing water in 30 s. [0114] Mixing for 1 min 30 s. [0115] Collection.

[0116] Forming of Blocks

[0117] Once the concrete was prepared, blocks comprising two cells were produced by casting the concrete in moulds and compacting thereof using fixed vibrator presses (vibro-compaction) using known, usual methods. To form the blocks (slab of 4 blocks of 152040 cm) the amount of material used was 15.6 Kg to obtain blocks weighing about 14 Kg.

[0118] Production and Application of the Mineral Foam Using the Method Described in Document WO2013/150148A1

[0119] The cement slurry was produced in a mixer of Rayneri type. The mixing protocol was as follows. The mineral foam was produced from a mixture of a cement slurry and aqueous foam that were continuously homogenised in a static mixer. This mineral foam may be of the same type as those described on pages 23 to 26 of the patent application published under number WO2013/150148A1 filed by the applicant (mineral foams 6 to 8).

[0120] To summarise, a cement slurry was obtained using a solid compound, or premix, comprising one or more hydraulic binders (e.g. Portland cement and/or slag) in a proportion of 50% by weight of the dry mixture. Water was added to the premix to obtain a cement slurry in proportions of about 20%5% by weight.

TABLE-US-00001 Time Speed Action .sup.0 to 10 Slow Dry mixing of binders 10 to 100 Slow Adding solution until formation of thickened portions 100 to 200 Fast Mixing the thickened portions 200 to 300 Slow Adding the remainder of the solution .sup.3 to 530 Semi-fast Mixing

[0121] A Rayneri Turbotest Mixer (MEXP-101) comprising deflocculating blades and speed varying from 1000 rpm to 400 rpm depending on the slurry volume, was used to hold the slurry under continuous agitation in the storage vessel after production thereof and before being pumped for injection into the static mixer.

[0122] The slurry can be pumped using a volumetric pump of Moineau type e.g. an eccentric screw Seepex BN025-12-W pump, commission number 244921.

[0123] The aqueous foam was obtained by foaming a solution of water and foaming agent such as Proprump 26 produced by Propump. Propump 26 is an animal protein having a molecular weight of about 6000 Daltons. The amount of water may vary from 75 to 98% by weight, e.g. in the region of 80%.

[0124] Other additives such as a thickening agent (e.g. Kelco-crete 200 biopolymer), or an accelerator such as calcium chloride can be added but are generally not required.

[0125] The aqueous solution of foaming agent was co-added with pressurised air to the foamer (range of 1 to 6 bars) by means of a T-junction. The aqueous foam was continuously generated. The foamer was formed of a bed of glass beads of SB30 type having a diameter of between 0.8 and 1.4 mm, packed in a tube of length 100 mm and diameter 12 mm.

[0126] The cement slurry was contacted with the aqueous foam already placed in circulation within the circuit and the foamed cement slurry was thus obtained.

[0127] Filling of the cells of the concrete block with the foamed slurry was performed continuously via a hose moved from one cell to another. Although operation was manual in this example, it can be automated, in particular since the cement slurry does not contain any setting accelerator such as calcium aluminate.

Example 1

Filling of a Mineral Masonry Block in the Fresh State

[0128] According to a first variant of the invention, the cells of cement blocks (2) prepared in accordance with the above-described method with the Formula F33 concrete, were filled with cement foam (3) immediately after removal of said block (2) from the press (vibro-compactor) and mould release. The walls of the block cell were saturated with water (the theoretical water absorption value according to standard NF-EN 772-11 would be close to zero at 0.10 min in g/(m.sup.2.Math.s) if cohesion of the block allowed such measurement. After filling with the cement foam, the composite insulating mineral blocks (1) were placed under a Styrodur cover and left in place in situ for 24 hours. The outer appearance of these composite insulating mineral blocks (1) is illustrated in FIGS. 1 and 2.

[0129] This process was repeated with a block of lightweight cement of formula F 41.

Example 2

Filling of a Waterproofed Mineral Masonry Block

[0130] According to a second variant of the invention, cement blocks prepared following the above-described method using concrete of Formula F34 (waterproofed blocks) were placed under a Styrodur cover to reproduce the curing conditions generally observed in manufacturing units of masonry blocks. The temperature was close to 30 C. and humidity close to saturation. After setting and curing (at least 24 hours) the cells of these blocks, having walls with water absorption in accordance with standard NF-EN 772-11 of 0.6 g/(m.sup.2.Math.s) at 10 min, were filled with mineral cement foam. These composite insulating mineral blocks were placed under a Styrodur cover and left in place in situ for 24 hours.

Example 3

Filling of a Mineral Masonry Block in the Rehydrated Dry State

[0131] According to a third variant of the invention, cement blocks prepared according to the method described above using Formula F33 concrete (non-waterproofed blocks) were placed under a Styrodur cover for 48 hours to reproduce the curing and setting conditions generally observed in manufacturing units of masonry blocks. The temperature was close to 30 C. and humidity close to saturation.

[0132] After setting and curing, the block was re-wetted by sprinkling with large quantities of water for 20 seconds. The water absorption of the cell walls of the block (in accordance with standard NF-EN 772-11) was 2 g/(m.sup.2.Math.s) at 10 min.

[0133] The cells of these blocks were then filled with cement foam. These composite blocks were placed under a Styrodur cover and left in place in situ for 24 hours.

Example 4

Comparative Example: Filling of a Commercial Cement Block

[0134] A breeze block in standard cement produced by Fabemi was filled with a cement foam (5). The outer appearance of this composite block (4) after drying is illustrated in FIG. 3. The water absorption of the cell walls of the block (in accordance with standard NF-EN 772-11) was 6 g/(m.sup.2.Math.s) at 10 min.

[0135] Conclusion

[0136] The cement foam of the composite blocks obtained following the above-described method of the invention remained stable after drying. Not only did the foam remain attached to the walls from a visual viewpoint with no apparent shrinkage, but said blocks were able to be turned over to ensure that the foam remained attached to the walls. The foam did not become detached.

[0137] The cement foam inserted in the cells of a standard cement block (comparative Example 4) retracted and became detached from the cell walls.

Example 5

Example: Filling of a Commercial Mineral Masonry Concrete Block

[0138] Standard concrete blocks (breeze blocks produced by Fabemi) were filled with a cement foam. Three blocks were immersed in water for 24 hours and left to drain for 2 hours, 24 hours or 30 minutes. One block was not immersed (comparative block). Water absorption of the cell walls of the blocks, according to standard NF-EN 772-11, was variable as indicated in Table 1. They were then filled with cement foam. The state of the foam is described in Table 1 below.

TABLE-US-00002 TABLE 1 Water Foam absorption at 10 min adhesion Foam Foam in g/(m.sup.2 .Math. s) to block collapse cracking Without 5.9 poor 1.5 cm moderate immersion (comparative example) 24 h draining 4.1 moderate 0.5 cm none 2 h draining 2.1 good 0.4 cm none 30 min draining 1.3 good 0.3 cm none

Example 6

Example: Filling of a Commercial Lightweight Concrete Mineral Masonry Block

[0139] Lightweight concrete blocks containing pumice stone aggregate (sold under the trade name Fabtherm by Fabemi) were filled with a cement foam (5). Three blocks were immersed in water for 24 hours and drained for either 2 hours, 24 hours or 30 minutes. One block was not immersed (comparative block). Water absorption of the cell walls of the blocks, according to standard NF-EN 772-11, were variable as indicated in Table 2. They were then filled with cement foam. The state of the foam is described in Table 2 below.

TABLE-US-00003 Water Foam absorption at 10 min adhesion Foam Foam in g/(m.sup.2 .Math. s) to block collapse cracking Without 11.8 poor 1.1 cm major immersion (comparative example) 24 h draining 4.9 moderate 0.3 cm none 2 h draining 2.5 good 0.1 cm none 30 min draining 1.8 good 0.1 cm none

[0140] The invention is not limited to the embodiments presented, and other embodiments will be clearly apparent to persons skilled in the art. In particular, it is possible to accelerate the setting of the composite blocks once the cement foam has been inserted in the cells, using known methods such as heating.