NOVEL CEMENT COMPOSITION FOR 3D PRINTING AND METHOD OF USE

Abstract

A novel cement composition for 3D printing including has 90% to 99.5% by weight of one or more cements selected from a Portland cement, an aluminous cement, a sulphoaluminous cement and a prompt natural cement; and has 0.5% to 10% by weight of a silicoaluminous filler having a specific surface area of at least 5 m.sup.2/g, as well as a method for implementing the composition.

Claims

1. A cement composition for 3D printing comprising: from 90% to 99.5% by weight of one or more cements selected from a Portland cement, an aluminous cement, a sulphoaluminous cement and a prompt natural cement; and from 0.5% to 10% by weight of a silicoaluminous filler having a specific surface area of at least 5 m.sup.2/g.

2. The cement composition according to claim 1, wherein it contains from 95% to 99.5% by weight of cement.

3. The cement composition according to claim 1, wherein it contains from 10% to 95% by weight relative to the total weight of cement of a Portland cement.

4. The cement composition according to claim 1, wherein it contains from 5% to 95% by weight relative to the total weight of cement of an aluminous cement, of a sulphoaluminous cement and/or a prompt natural cement.

5. The cement composition according to claim 1, wherein it contains a Portland cement and a sulfoaluminous cement.

6. The cement composition according to claim 1, wherein it contains from 0.5% to 5% by weight of silicoaluminous filler having a specific surface area of at least 5 m.sup.2/g.

7. The cement composition according to claim 1, wherein the silicoaluminous filler is selected from natural pozzolans, calcined clays and silica fume.

8. The cement composition according to claim 1, wherein it further contains a limestone filler and/or a setting retarder.

9. A 3D printing method comprising the following steps: contacting the cement composition according to claim 1 with water optionally added with superplasticizer and mixing of the whole; pumping of the composition thus obtained to the print head and possible addition of a setting trigger; printing.

10. A useful kit for the preparation of a cement composition for 3D printing according to claim 1, said kit comprising: on the one hand a Portland cement and optionally a limestone filler and/or a setting retarder; and on the other hand an aluminous, sulphoaluminous and/or prompt natural cement and optionally a limestone filler and/or a setting retarder; the silicoaluminous filler having a specific surface area of at least 5 m.sup.2/g which may be present in the element of the kit containing the Portland cement and/or in the element of the kit containing the aluminous, sulphoaluminous and/or prompt natural cement.

11. A 3D printing method implementing the kit according to claim 10 comprising the following steps: contacting the composition containing Portland cement optionally added with superplasticizer with water and mixing the whole and, separately, bringing the composition containing the aluminous, sulphoaluminous and/or natural prompt cement into contact with water optionally added with superplasticizer and mixing of the whole; pumping each of the compositions thus obtained to the print head, bringing them into contact, optionally in the presence of a setting trigger; printing.

Description

EXAMPLE 1—CEMENT INK CONTAINING A SINGLE CEMENT

[0106] 1.1—Composition

[0107] An ink for 3D printing (E-1) whose characteristics are reported in Table 1 below was prepared from a «one-component» cement ink.

TABLE-US-00001 TABLE 1 Ink E-1 for 3D printing Con- Weight/ mass stituent Type Volume % Premix Portland CEM I 52.5 R 562 g 28.1 Cement limestone Omya Btocarb 663 g 33.2 filler HP Metakaolin Argical 1000 10 g 0.5 Silica sand Sibelco HN31 765 g 38.3 Liquid Super- Chryso Optima 9 ml 1.6 adjuvan- plasticizer 145 (% tation binder) Setting Chryso Jet 1000 Adjustable trigger volume Water Premix 2000 g W/C = 0.48 Water  270 g

[0108] 1.2—Preparation and Monitoring of Rheology

[0109] The ink E-1 was prepared in the laboratory in a mixer according to the following procedure: [0110] dry mixing for 45s of all the dry constituents to homogenize the mixture; [0111] addition of water and superplasticizer in 15 s (=T.sub.0); [0112] mixing the whole for 3 minutes at low speed.

[0113] The rheology of the obtained composition (without adding a setting accelerator) was monitored at T.sub.0+3 min, T.sub.0+20 min and T.sub.0+30 min and T.sub.0+60 min by spreading on an ASTM cone (without shaking table). The results are reported in Table 2 below.

TABLE-US-00002 TABLE 2 Ink E-1 rheology monitoring Time Spreading (mm) T.sub.0 + 3 minutes  175 T.sub.0 + 20 minutes 180 T.sub.0 + 30 minutes 180 T.sub.0 + 60 minutes 180

[0114] There is no significant change in the rheology of the ink during the first 60 minutes and before setting triggering. The obtained rheology enables the pumping and use of the ink E-1 in a 3D print head.

[0115] 1.3—Strengths after Triggering

[0116] The properties of the ink in terms of compressive strength with or without the addition of a setting accelerator (addition at T.sub.0+10 min using a syringe) were evaluated according to the following protocol: [0117] preparation of the cement ink according to the mixing protocol described in Example 2.2; [0118] at t.sub.0+10 min, adding 5 ml of setting trigger; [0119] mixing at low speed for 15 seconds; [0120] placing in 4×4×16 molds in a single pass (i.e. the mold is filled then undergoes 60 shocks in one minute).

[0121] The results obtained in terms of compressive strength (CS) are reported in Table 3 below.

TABLE-US-00003 TABLE 3 Ink E-1 compressive strength Volume of setting accelerator added (in ml) at T.sub.0 + 10 min 5 CS (MPa) 24 h 42.9 7 days 81.2 28 days 92.1

[0122] The observed strengths are compatible with the use of the ink E-1 in 3D printing.

EXAMPLE 2—ONE-COMPONENT CEMENT INK

[0123] 2.1—Composition

[0124] An ink for 3D printing (E-2) whose characteristics are reported in Table 4 below was prepared from a «one-component» cement ink.

TABLE-US-00004 TABLE 4 Ink E-2 for 3D printing Weight/ Constituent Type Volume mass % Premix Portland CEM I 52.5 N 350 g 17.5 Cement Sulpho- Alpenat R.sup.2 150 g 7.5 aluminous cement Limestone Omya Btocarb 400 g 20.0 filler HP Metakaolin Argical 1000 100 g 5.0 Silica sand Sibelco HN31 1000 g 50.0 Solid Retarder Citric acid 2.5 g 0.5 adjuvan- (% binder) tation Setting trigger Lithium 2.0 g 0.4 carbonate (% binder) Liquid Super- Chryso Optima 7.5 ml 1.5 adjuvan- plasticizer 145 (% binder tation Setting trigger Chryso Jet 1000 Adjustable volume Water Premix 2005.5 g W/C = 0.55 Water   276 g

[0125] 2.2—Preparation and Monitoring of Rheology

[0126] The ink E-2 was prepared in the laboratory in a mixer according to the following procedure: [0127] dry mixing for 45s of all the dry constituents to homogenize the mixture; [0128] addition of water and superplasticizer in 15 s (=T.sub.0); [0129] mixing the whole for 3 minutes at low speed.

[0130] The rheology of the obtained composition (without adding setting accelerator) was monitored at T.sub.0+3 min, T.sub.0+15 min and T.sub.0+30 min by flow of 15 cm at the ASTM cone (without shaking table). The results are reported in Table 5 below.

TABLE-US-00005 TABLE 5 Ink E-2 rheology monitoring Time Spreading (mm) T.sub.0 + 3 minutes  152.5 T.sub.0 + 15 minutes 165 T.sub.0 + 30 minutes 150

[0131] There is no significant change in the rheology of the ink during the first 30 minutes and before setting triggering. The obtained rheology enables the pumping and use of the ink E-1 in a 3D print head.

[0132] 2.3—Strengths after Triggering

[0133] The properties of the ink in terms of compressive strength with or without the addition of a setting accelerator (addition at T.sub.0+10 min using a syringe) were evaluated according to the following protocol: [0134] preparation of the cement ink according to the mixing protocol described in Example 2.2; [0135] at t0+10 min, add 0 to 15 ml of setting trigger; [0136] mixing at low speed for 15 seconds; [0137] placing in 4×4×16 molds in a single pass (i.e. the mold is filled then undergoes 60 shocks in one minute).

[0138] The results obtained in terms of compressive strength (CS) are reported in Table 6 below.

TABLE-US-00006 TABLE 6 Ink E-2 compressive strength Volume of setting accelerator added (in ml) at T.sub.0 + 10 min 0 5 10 15 CS (MPa) 24 h 15.4 14.2 13.7 12.9 7 days 51.6 49.4 44.5 42.3 28 days 93.3 86.2 80.7 77.7

[0139] The observed strengths are compatible with the use of the ink E-2 in 3D printing, regardless of the expiration date and or the added amount of setting accelerator. The decrease in CS due to the addition of the setting trigger was expected. However, it remains moderate.

EXAMPLE 3—ONE-COMPONENT CEMENT INKS

[0140] 3.1—Compositions

[0141] Two inks for 3D printing (E-3 and E-4) whose characteristics are reported in Tables 7 and 8 below were prepared from a «one-component» cement ink.

TABLE-US-00007 TABLE 7 Ink E-3 for 3D printing Weight/ Constituent Type Volume mass % Premix Portland CEM I 52.5 N 427.13 g 21.3 Cement Sulpho- Alpenat R.sup.2 75.38 g 3.8 aluminous cement Limestone Omya Betocarb 402 g 20.0 filler HP Metakaolin Argical 1000 100.5 g 5.0 Silica sand Sibelco HN31 1000.5 g 49.9 Solid Retarder Citric acid 3.52 g 0.7 adjuvan- (% binder) tation Hardener Lithium 2.01 g 0.4 carbonate (% binder) Liquid Super- Chryso Optima 9.5 ml 1.9 adjuvan- plasticizer 145 (% binder) tation Setting Chryso Jet Adjustable trigger 1000 volume Water Premix 2010.0 g W/C = 0.54 Water   269 g

TABLE-US-00008 TABLE 8 Ink E-4 for 3D printing Weight/ Constituent Type Volume mass % Premix Portland CEM I 52.5 N 412.25 g 21.3 Cement Sulpho- Alpenat R.sup.2 72.75 g 3.8 aluminous cement Limestone Omya 630.5 g 32.5 filler Betocarb HP Metakaolin Argical 1000 97 g 5.0 Silica sand Sibelco HN31 727.5 g 37.5 Solid Retarder Citric acid 4.85 g 1.0 adjuvan- (% binder) tation Hardener Lithium 1.94 g 0.4 carbonate (% binder) Liquid Super- Chryso 9.5 ml 2.0 adjuvan- plasticizer Optima 145 (% binder) tation Setting Chryso Jet Adjustable trigger 1000 volume Water Premix 1940 g W/C = 0.58 Water  285 g

[0142] 3.2—Preparation and Monitoring of Rheology

[0143] The inks E-3 and E-4 were prepared in the laboratory in a mixer according to the following procedure: [0144] dry mixing for 45s of all the dry constituents to homogenize the mixture; [0145] addition of water and superplasticizer in 15 s (=T.sub.0); [0146] mixing the whole for 3 minutes at low speed.

[0147] The rheology of the obtained composition (without adding setting accelerator) was monitored at different times between T.sub.0+3 min and T.sub.0+135 min by flow of 15 cm at the ASTM cone (without shaking table). The results are reported in Table 9 below.

TABLE-US-00009 TABLE 9 Inks E-3 and E-4 rheology monitoring Spreading (mm) Time E-3 E-4 T.sub.0 + 3 minutes  190 170 T.sub.0 + 15 minutes 225 215 T.sub.0 + 30 minutes 280 230 T.sub.0 + 55 minutes 285 232 T.sub.0 + 75 minutes 292 225 T.sub.0 + 95 minutes 290 222  T.sub.0 + 115 minutes 285 205  T.sub.0 + 135 minutes 272 195

[0148] There is no significant change in the rheology of the inks during the first 30 minutes and before the setting triggering. An increase in spreading is observed initially and then a gradual decrease («bell effect») characteristic of highly adjuvanted materials. However, after more than two hours, the spread is still greater than 200 mm, which allows for any risk of setting in the print head. The obtained rheology therefore allows the use of inks E-3 and E-4 in a 3D print head.

EXAMPLE 4—TWO-COMPONENT CEMENT INK

[0149] A two-component cement ink (E-5) whose characteristics are reported in Table 10 below was prepared.

TABLE-US-00010 TABLE 10 Ink E-5 for 3D printing Comp- Comp- Constituent Type onent A onent B Premix Portland CEM I — 50 g Cement 52.5 N Sulpho- Alpenat R.sup.2 33 g — aluminous cement Limestone Omya — 17 g filler Betocarb HP Solid Retarder Citric acid 0.1 g 0.07 g adjuvan- Setting Lithium — 0.17 g tation trigger carbonate Water 17.5 g 17.5 g

[0150] In the example presented above, lithium carbonate has a very moderate effect on the increase in strength of Portland cement considered alone and it does not or very little disrupt its rheology. After mixing, the formed binder consists of Alpenat R.sup.2 and Portland cement CEM I in proportions of 60/40, formula setting in a few seconds, and the lithium carbonate then accelerates the increase in strength of the mixture. This «cross-adjuvantation» allows the introduction of adjuvants having a powerful effect on one component (A) via the other component (B), their effect only being triggered when the two components meet.

[0151] Each component of the ink has been prepared separately. The dry materials were mixed for 45 seconds at low speed then water was added for 15 seconds. The cement paste is then mixed for one minute at low speed.

[0152] The two components were then introduced into syringes connected to a static mixer in which they are brought into contact.

[0153] At the output of this mixer, the mixture of the two components has set and the material has passed from the liquid state to that of thick paste in a few seconds without it being necessary to add liquid adjuvants such as a superplasticizer or a setting trigger.

EXAMPLE 5—COMPARATIVE TESTS

[0154] 5.1—Tested Compositions

[0155] The inks for 3D printing (E-6 to E-9) whose characteristics are reported in Tables 11 to 14 below, were prepared from a «one-component» cement inks.

TABLE-US-00011 TABLE 11 Ink E-6 for 3D printing Weight/ Constituent Type Volume Premix Portland CEM I 52.5 N 425 g Cement Sulpho- Alpenat R.sup.2 75 g aluminous cement Limestone Omya 650 g filler Betocarb HP Metakaolin Argical 1000 100 g Silica sand Sibelco HN31 750 g Solid Retarder Citric acid 5 g adjuvan- Hardener Lithium 2 g tation carbonate Liquid Super- Chryso Optima 9.8 ml adjuvan- plasticizer 145 tation Setting trigger Chryso Jet 1000 10 ml Water Premix 2000 g W/C = 0.59 Water 293.8 ml

TABLE-US-00012 TABLE 12 Ink E-7 for 3D printing Weight/ Constituent Type Volume Premix Portland CEM I 52.5 N 425 g Cement Sulpho- Alpenat R.sup.2 75 g aluminous cement Limestone Omya 750 g filler Betocarb HP Metakaolin Argical 1000 — Silica sand Sibelco HN31 750 g Solid Retarder Citric acid 5 g adjuvan- Hardener Lithium 2 g tation carbonate Liquid Super- Chryso Optima 9.8 ml adjuvan- plasticizer 145 tation Setting trigger Chryso Jet 10 ml 1000 Water Premix 2000 g W/C = 0.59 Water 293.8 ml

TABLE-US-00013 TABLE 13 Ink E-8 for 3D printing Poids/ Constituent Type Volume Premix Portland CEM I 52.5 N 561.3 g Cement Sulpho- Alpenat R.sup.2 — aluminous cement Limestone Omya 663.3 g filler Betocarb HP Metakaolin Argical 1000 10 g Silica sand Sibelco HN31 765.4 g Solid Retarder Citric acid — adjuvan- Hardener Lithium — tation carbonate Liquid Super- Chryso Optima 9 ml adjuvan- plasticizer 145 tation Setting Chryso Jet 1000 10 ml trigger Water Premix 2000 g W/C = 0.48 Water 270 ml

TABLE-US-00014 TABLE 14 Ink E-9 for 3D printing Poids/ Constituent Type Volume Premix Portland CEM I 52.5 N 561.3 g Cement Sulpho- Alpenat R.sup.2 — aluminous cement Limestone Omya Betocarb 673.3 g filler HP Metakaolin Argical 1000 — Silica sand Sibelco HN31 765.4 g Solid Retarder Citric acid — adjuvan- Hardener Lithium — tation carbonate Liquid Super- Chryso Optima 9 ml adjuvan- plasticizer 145 tation Setting trigger Chryso Jet 10 ml 1000 Water Premix 2000 g W/C = 0.48 Water 270 ml

[0156] 5.2—Preparation and Monitoring of Rheology

[0157] Inks E-6 to E-9 were prepared in the laboratory in a mixer according to the following procedure: [0158] dry mixing for 45s of all the dry constituents to homogenize the mixture; [0159] addition of water and superplasticizer in 15 s (=T.sub.0); [0160] mixing the whole for 3 minutes at low speed.

[0161] The indicated amount of setting trigger (Chryso Jet 1000 AF) is then added and the ink is mixed again for 30 seconds.

[0162] Layers of material are then stacked successively in order to validate the «buildability» criterion or the ability of the ink to support its own weight and that of successive layers.

[0163] For this experiment, a cylindrical die of 40 mm diameter and 30 mm high is used. Successive layers are added at a rate of 1 layer every 30 seconds.

[0164] This test makes it possible to study the behavior of the first deposited layer when the load applied to it increases.

[0165] It is observed that for inks E-7 and E-9 (which do not contain silicoaluminous filler), the threshold generated after triggering of the setting is too low. The bottom layer begins to sag as soon as the second layer is deposited and it gives out completely after a few more layers (3 for E-7 ink and 5 for E-9 ink).

[0166] On the contrary, the E-6 and E-8 inks (which contain a silicoaluminous filler) allow a stacking of layers up to at least 20 successive layers without observing deformation or sagging of the lower layer.