Method for the construction of a data center

Abstract

A method for the construction of a data center, includes (a) providing a fresh concrete composition including a paste that includes a hydraulic binder, a mineral addition and water, the paste being present in a mixture with sand and aggregates, whereby the paste is present in the concrete composition in a volume of <320 L/m.sup.3 and/or the solid volume fraction of said paste is >50 vol.-% and (b) placing the fresh concrete composition so as to build walls, a floor and/or a ceiling of the data center, which are intended to surround the individual components of computer systems, which are housed in the data center.

Claims

1. A method for the construction of a data center, comprising (a) providing a fresh concrete composition comprising a paste that comprises a hydraulic binder, a mineral addition other than sand and aggregates, and water, said paste being in a mixture with sand and aggregates, whereby the paste is present in the fresh concrete composition in a volume of <320 L/m.sup.3 and/or the solid volume fraction of said paste is >50 vol.-%, and (b) placing said fresh concrete composition so as to build walls, a floor and/or a ceiling of the data center, which are intended to surround individual components of computer systems, which are housed in the data center, wherein said sand and aggregates comprise magnetite sand and/or magnetite aggregate.

2. The method according to claim 1, wherein the paste is present in the fresh concrete composition in a volume of <300 L/m.sup.3.

3. The method according to claim 1, wherein the solid volume fraction of said paste is >55 vol.-%.

4. The method according to claim 1, wherein water is present in the fresh concrete composition in a volume of <170 L/m.sup.3.

5. The method according to claim 1, wherein the fresh concrete composition comprises 1.5 to 12 kg per m.sup.3 of the fresh concrete composition of a water reducer, a plasticizer or a superplasticizer.

6. The method according to claim 1, wherein Portland cement is used as said hydraulic binder.

7. The method according to claim 1, wherein the hydraulic binder is present in the fresh concrete composition in an amount of 150-500 kg/m.sup.3.

8. The method according to claim 1, wherein a limestone filler or a siliceous filler or a mixture of limestone filler and a siliceous filler is used as said mineral addition.

9. The method according to claim 8, wherein the mineral addition has a particle size distribution that is characterised by a D50 of ≤10 μm and/or a D98 of ≤100 μm.

10. The method according to claim 1, wherein a hematite filler is used as said mineral addition.

11. The method according to claim 1, wherein the skeleton packing density of the aggregate is selected to be >0.69.

12. The method according to claim 1, wherein the fresh concrete composition comprises a super-plasticiser.

13. The method according to claim 1, wherein the fresh concrete, after having been placed, is allowed to harden and dry, wherein the thermal resistivity of the concrete once hardened and dried is <0.7 m.Math.K/W.

14. The method according to claim 13, wherein the 28d compressive strength of the concrete is >20 MPa.

15. The method according to claim 1, wherein the concrete composition is free from a material having a thermal conductivity of >10 W/m.Math.K.

16. The method according to claim 15, wherein the concrete composition is free from a material having a thermal conductivity of >20 W/m.Math.K.

17. The method according to claim 8, wherein said mineral addition includes fine quartz and/or silica flour.

18. A method for the construction of a data center, comprising (a) providing a fresh concrete composition comprising a paste that comprises a hydraulic binder, a mineral addition other than sand and aggregates, and water, said paste being in a mixture with sand and aggregates, whereby the paste is present in the fresh concrete composition in a volume of <300 L/m.sup.3 and the solid volume fraction of said paste is >45 vol.-%, and (b) placing said fresh concrete composition so as to build walls, a floor and/or a ceiling of the data center, which are intended to surround individual components of computer systems, which are housed in the data center, wherein said sand and aggregates comprise magnetite sand and/or magnetite aggregate.

Description

DETAILED DESCRIPTION

(1) The invention will now be described in more detail with reference to the following examples.

(2) In the examples fresh concrete compositions were mixed according to the following process. The fresh concrete mixes were obtained by means of a ZYCLOS type mixer. The whole operation has been carried out at 20° C. The method of preparation comprises the following steps: At T=0 seconds: charging the cement and the sand in a bowl mixer and mixing during 7 minutes (15 rpm); At T=7 minutes: adding water and half of the weight of additive (superplasticizer) and mix for 1 minute (15 rpm); At T=8 minutes: adding the rest of the additive (superplasticizer) and mix for 1 minute (15 rpm); At T=9 minutes: mixing for 8 minutes (50 rpm); and At T=17 minutes: mixing for 1 minute (15 rpm); At T=18 minutes: pouring the concrete on the level into a mould.

(3) The performance of the fresh concrete mixes was measured according to the following process. Concrete slump and strength measurements were carried out as described in the standard NF EN 206 published in November 2016. Strength was measured on 10 cm×10 cm×10 cm cubes. The thermal resistivity, including definition of the dry state, was measured using a Decagon device (KD2 pro with probe RK-1) according to the standard IEEE 442, on concrete cubes (10 cm×10 cm×10 cm) dried at 105° C. until constant mass and cooled in desiccator to room temperature.

(4) In the examples below, the thermal resistivity is measured when the material is dry as described above. If the material still contains some free water, the thermal resistivity would decrease.

Example 1

(5) Fresh compositions for concrete with the mix designs indicated in Table 1 have been prepared and allowed to harden and dry. The performance parameters of the concrete compositions have been determined and are listed in Table 2.

(6) An analysis of the examples allows to draw the following conclusions.

(7) Mix design C02 is a prior art mix design with limestone as a mineral filler material.

(8) In the mix design C03, limestone filler was replaced by fly ash, wherein the performance measurements show that the thermal resistivity did not decrease, but increased.

(9) A comparison of the mix designs C04 and C05 with C02 shows that reducing the water content of the fresh concrete composition results in a reduction of the thermal resistivity, and also increases the compressive strength.

(10) A comparison of the mix designs C12 and C14 reveals that reducing the paste volume (i.e. the volume of water, binder and limestone filler) decreases the thermal resistivity.

(11) A comparison of the mix designs C13 and C13B shows the effect of the type of gravel, wherein using a siliceous type gravel (sourced from La Gerbaudière) results in a reduced thermal resistivity when compared to a siliceous-lime gravel (sourced from Saint Bonnet).

(12) A comparison of the mix designs C23 and C23B shows the effect of the type of sand on the thermal resistivity, wherein natural rounded sand results in a reduced thermal resistivity when compared to manufactured and washed sand.

(13) The mix design C41 was identified as the reference mix design having a very low thermal resistivity of 0.47 (m.Math.K)/W.

(14) With the mix design C41 Sflour, the limestone filler was partly replaced by silica flour, in order to further decrease thermal resistivity.

(15) The mix design C41 MAGN shows that the use of Fe.sub.3O.sub.4 sands and gravel further decreases the thermal resistivity.

(16) With the mix design C41 Hema, the limestone filler was partly replaced by a Fe.sub.2O.sub.3 filler, which further decreases the thermal resistivity.

(17) A comparison of the mix designs C11 and C41 shows that the use of carbon can be avoided by mix design optimization, the specific concrete mix design is more important than the conductive additives.

(18) TABLE-US-00001 TABLE 1 Unit C02 C03 C04 C05 C11 C12 C14 C13 C13B CEM I - CEM I 52.5 N Saint Pierre kg/m.sup.3 40 40 40 40 25 41 36 39 39 La Cour Limestone filler St beat Omya kg/m.sup.3 360 0 0 0 0 0 0 0 0 Limestone filler Cat. A - BL200 kg/m.sup.3 0 0 405 460 360 373 322 351 351 (Omya) Fly ash Cordemais kg/m.sup.3 0 360 0 0 0 0 0 0 0 Silica flour (siliceous fine filler) kg/m.sup.3 0 0 0 0 0 0 0 0 0 Hematite filler kg/m.sup.3 0 0 0 0 0 0 0 0 0 Synthetic graphite kg/m.sup.3 0 0 0 0 100 0 0 0 0 Micro sand Sibelco Be01 kg/m.sup.3 182 167 184 184 184 179 192 193 193 Crushed and washed sand 0/4 kg/m.sup.3 0 0 0 0 0 0 0 779 779 (Petit Craz) Natural sand 0/5 (Saint Bonnet) kg/m.sup.3 734 674 742 742 756 720 773 0 0 Aggregates 5/10 (Saint Bonnet) kg/m.sup.3 788 723 797 797 815 773 831 837 0 Aggregates 4/10 (La Gerbaudière) kg/m.sup.3 0 0 0 0 0 0 0 0 985 F.sub.3O.sub.4 sand 0/2 (Garrot-Chaillac) kg/m.sup.3 0 0 0 0 0 0 0 0 0 F.sub.3O.sub.4 sand 0/6 (Garrot-Chaillac) kg/m.sup.3 0 0 0 0 0 0 0 0 0 F.sub.3O.sub.4 sand 4/16 (Garrot-Chaillac) kg/m.sup.3 0 0 0 0 0 0 0 0 0 Superplasticizer Chryso Optima kg/m.sup.3 4 0 1.78 2.00 1.54 1.24 1.43 5.60 5.60 203 Kelcocrete (viscosity modifying kg/m.sup.3 0 0 0 0 0 0 0 0 0 agent) Superplasticizer Chryso Optima kg/m.sup.3 0 5.5 0 0 0 0 0 0 0 206 Total effective water L/m.sup.3 175 204 154 134 115 183 155 138 138 Air L/m.sup.3 20 20 20 20 20 20 20 20 20 C41 C41 C41 Unit C41 C23 C23B Hema Slfour MAGN CEM I - CEM I 52.5 N Saint Pierre kg/m.sup.3 15 36 36 15 15 15 La Cour Limestone filler St beat Omya kg/m.sup.3 0 0 0 0 0 0 Limestone filler Cat. A - BL200 kg/m.sup.3 370 415 415 248 248 370 (Omya) Fly ash Cordemais kg/m.sup.3 0 0 0 0 0 0 Silica flour (siliceous fine filler) kg/m.sup.3 0 0 0 0 116 0 Hematite filler kg/m.sup.3 0 0 0 196 0 0 Synthetic graphite kg/m.sup.3 0 0 0 0 0 0 Micro sand Sibelco Be01 kg/m.sup.3 79 192 192 79 79 0 Crushed and washed sand 0/4 kg/m.sup.3 681 0 773 681 681 0 (Petit Craz) Natural sand 0/5 (Saint Bonnet) kg/m.sup.3 0 773 0 0 0 0 Aggregates 5/10 (Saint Bonnet) kg/m.sup.3 1175 831 831 1175 1175 0 Aggregates 4/10 (La Gerbaudière) kg/m.sup.3 0 0 0 0 0 0 F.sub.3O.sub.4 sand 0/2 (Garrot-Chaillac) kg/m.sup.3 0 0 0 0 0 1033 F.sub.3O.sub.4 sand 0/6 (Garrot-Chaillac) kg/m.sup.3 0 0 0 0 0 1590 F.sub.3O.sub.4 sand 4/16 (Garrot-Chaillac) kg/m.sup.3 0 0 0 0 0 1056 Superplasticizer Chryso Optima kg/m.sup.3 7.70 1.43 1.43 7.70 7.70 7.70 203 Kelcocrete (viscosity modifying kg/m.sup.3 0.0015 0.0036 0.0036 0.0015 0.0015 0.0015 agent) Superplasticizer Chryso Optima kg/m.sup.3 0 0 0 0 0 0 206 Total effective water L/m.sup.3 90 121 121 90 90 90 Air L/m.sup.3 20 20 20 20 20 20

(19) TABLE-US-00002 TABLE 2 Paste Solid Thermal Compressive volume volume resistivity strength at without fraction at dry state Slump 28 days air of paste Unit (m .Math. K)/W cm MPa L/m.sup.3 % C02 0.81 >20 2.0 320 45.3 C03 0.90 >20 2.0 358 43.0 C04 0.62 >20 2.7 316 51.2 C05 0.56 >20 4.9 316 57.6 C11 0.52 >20 1.9 301 61.8 C12 0.84 >20 1.1 333 45.1 C14 0.66 >20 1.5 285 45.6 C13 0.69 >20 2.0 280 50.6 C13B 0.63 >20 2.0 280 50.6 C41 0.47 >20 2.0 231 61.0 C23 0.54 >20 1.9 285 57.5 C23B 0.65 >20 4.9 285 57.5 C41 0.44 >20 1.9 228 60.5 Hema C41 0.45 >20 2.0 229 60.7 Sfour C41 0.46 >20 1.7 231 61.0 MAGN

Examples 2

(20) Fresh compositions for concrete with the mix designs indicated in tables 3 to 6 have been prepared and allowed to harden and dry. The performance parameters of the concrete compositions have been determined and are also listed in tables 3 to 6.

(21) TABLE-US-00003 TABLE 3 Material Dosage, kg/m.sup.3 Cement (CEM I) 220 Limestone filler BL 200 281 Orgon silica fume 22 Washed sand 0/4 682 Natural round gravel (5/10) 1051 Superplasticizer (Chryso 11 Optima 100) Effective water 129 Paste volume 310 L/m.sup.3 Paste solid volume fraction 0.59 (without air) Aggregate packing density 0.68 Slump 25 cm Thermal resistivity at dry state 0.35 m .Math. K/W compressive strength at 28 day 60 MPa

(22) TABLE-US-00004 TABLE 4 Material Dosage, kg/m.sup.3 Cement (CEM I) 159 limestone filler saint Beat 220 silica fume 55.9 ultrafine limestone filler 73.1 omyacoat 850 fine sand la sabliére 132.3 CCSH washed sand 0/4 682 natural round gravel (5/20) 1080 superplasticizer (Chryso 11 Optima 100) effective water 127 Paste volume 309 L/m.sup.3 paste solid volume fraction 0.59 (without air) slump >25 cm aggregate packing density 0.71 thermal resistivity at dry state 0.31 m .Math. K/W compressive strength at 28 day 70 MPa

(23) TABLE-US-00005 TABLE 5 Material Dosage, kg/m.sup.3 Cement (CEM I) 207 Fine limestone filler 297 Betoflow D SL silica fume 39 washed sand 0/4 687 natural round gravel (5/10) 1066 superplasticizer (Chryso 5.4 Optima 203) effective water 105 Paste volume 298 L/m.sup.3 paste solid volume fraction 0.64 (without air) slump >25 cm aggregate packing density 0.68 thermal resistivity at dry state 0.33 m .Math. K/W compressive strength at 28 day 76 MPa

(24) TABLE-US-00006 TABLE 6 Material Dosage, kg/m.sup.3 Cement (CEM I) 462 silica fume 30 washed sand 0/4 687 natural round gravel (5/10) 1066 superplasticizer (Chryso 4.9 Optima 203) effective water 138 Paste volume 298 L/m.sup.3 paste solid volume fraction 0.54 (without air) slump >25 cm aggregate packing density 0.68 thermal resistivity at dry state 0.4 m .Math. K/W compressive strength at 28 day 92 MPa