Healing agent for self-healing cementious material
The invention provides a process for the production of a cementious material. The process comprises mixing cement starting materials and a particulate healing agent to provide the cementious material. The healing agent comprises coated particles, wherein the coated particles comprise bacterial material and additive. The bacterial material is selected from the group consisting of a bacterium, a lyophilized bacterium and a bacterial spore of a bacterium. The present invention solves these problems, as (substantially leakage-proof) tablets containing the actual healing agent may neither interfere with either the workability of the liquid mixture (“cementious material”) nor negatively affect properties of either mixture or final material (hardened concrete), even when applied in large quantities. During crack formation in cementious based constructions, the particles also crack, and healing agent is released.
1. A process for the production of a cementious material, comprising mixing cement starting materials and a particulate healing agent to provide the cementious material, wherein the healing agent comprises coated particles, wherein the coated particles have a coating thickness in the range 5 μm-2 mm, wherein the coated particles comprise bacterial material and additive, and wherein the bacterial material is selected from the group consisting of a bacterium, a lyophilized bacterium and a bacterial spore of a bacterium.
2. The process according to claim 1 , wherein the bacterium is selected from the group consisting of aerobic bacteria.
3. The process according to claim 1 , wherein the bacterium is selected from the group consisting of anaerobic bacteria.
4. The process according to claim 1 , wherein the bacterium is selected from the group consisting of bacteria that can form a phosphate or a carbonate precipitate in an alkaline medium.
5. The process according to claim 1 , wherein the bacterium is selected from the group of genera consisting of Planococcus, Bacillus and Sporosarcina.
6. The process according to claim 1 , wherein the additive comprises a calcium compound.
7. The process according to claim 6 , wherein the additive comprises one or more compounds selected from the group consisting of calcium formate, calcium acetate, calcium lactate, and calcium gluconate.
8. The process according to claim 1 , wherein the additive comprises one or more compounds selected from the group consisting of an organic compound and a phosphor compound.
9. The process according to claim 8 , wherein the additive comprises one or more compounds selected from the group consisting of a yeast extract, a peptone, a carbohydrate, a fatty acid, an amino acid, a lactate, a glutamate, an aspartate, a maleate, a formate, a pyruvate, a sugar and a phytate.
10. The process according to claim 1 , wherein the additive comprises trace elements.
11. The process according to claim 1 , wherein the additive comprises (1) one or more compounds selected from the group consisting of calcium formate, calcium acetate, calcium lactate, calcium gluconate, a carbohydrate, a fatty acid, a amino acid, a lactate, a maleate, a formate, a sugar, a pyruvate and a phytate and (2) a bacterial growth factor selected from the group consisting of a yeast extract, a peptone, an aspartate, a glutamate and trace elements.
12. The process according to claim 1 , where the additive comprises (a) a calcium compound, (b) one or more of an organic compound and a phosphor compound, (c) trace elements and (d) one or more of a yeast extract, a peptone, an aspartate, and a glutamate.
13. The process according to claim 1 , wherein the weight ratio bacterial material:additive of the particulate healing agent is in the range of 1:10,000-1:1,000,000.
14. The process according to claim 1 , wherein the coated particles comprise at least 50 wt. % bacterial material and additive, relative to the total weight of the coated particles.
15. The process according to claim 1 , wherein the coated particles have mean dimensions in the range of 0.2-4 mm.
16. The process according to claim 1 , wherein the coating comprises a (co)polymer based coating based on one or more monomer types selected from the group comprising glycolide, lactide, ε-caprolactone, δ-valerolactone, N-vinylcaprolactam, 3,6-dimethyl-1,4-dioxane-2,5-dione, glycosyloxyethyl methacrylate, 1,6-bis(p-acetoxycarbonylphenoxy)hexane and (3S)-cis-3,6-dimethyl-1,4-dioxane-2,5-dione.
17. The process according to claim 1 , wherein the coating comprises an epoxy based (co)polymer.
18. The process according to claim 1 , wherein the coated particles have a mean particle hardness in the range of 3-9 according to Mohs scale.
19. The process according to claim 1 , wherein the weight ratio of the cement starting materials to the particulate healing agent is in the range of 2,000:1-20:1.
20. The process according to claim 1 , wherein the weight ratio of the cement starting materials to the bacterium is in the range of 1.10 6 :1-1.10 8 :1.
21. A process for the production of a cementious material, comprising mixing cement starting materials and a particulate healing agent to provide the cementious material, wherein the healing agent comprises coated particles, wherein the coated particles comprises a (co)polymer-based coating, wherein the coated particles comprise bacterial material and additive, and wherein the bacterial material is selected from the group consisting of a bacterium, a lyophilized bacterium and a bacterial spore of a bacterium.
22. The process according to claim 21 , wherein the (co)polymer-based coating is based on one or more monomer types selected from the group consisting of glycolide, lactide, ε-caprolactone, δ-valerolactone, N-vinylcaprolactam, 3,6-dimethyl-1,4-dioxane-2,5-dione, glycosyloxyethyl methacrylate, 1,6-bis(p-acetoxycarbonylphenoxy)hexane, and (3S)-cis-3,6-dimethyl-1,4-dioxane-2,5-dione.
23. The process according to claim 21 , wherein the bacterium is selected from the group consisting of aerobic bacteria.
24. The process according to claim 21 , wherein the bacterium is selected from the group consisting of anaerobic bacteria.
25. The process according to claim 21 , wherein the bacterium is selected from the group consisting of bacteria that can form a phosphate or a carbonate precipitate in an alkaline medium.
26. The process according to claim 21 , wherein the bacterium is selected from the group of genera consisting of Planococcus, Bacillus and Sporosarcina.
27. The process according to claim 21 , wherein the additive comprises a calcium compound.
28. The process according to claim 27 , wherein the additive comprises one or more compounds selected from the group consisting of calcium formate, calcium acetate, calcium lactate, and calcium gluconate.
29. The process according to claim 21 , wherein the additive comprises one or more compounds selected from the group consisting of an organic compound and a phosphor compound.
30. The process according to claim 29 , wherein the additive comprises one or more compounds selected from the group consisting of a yeast extract, a peptone, a carbohydrate, a fatty acid, an amino acid, a lactate, a glutamate, an aspartate, a maleate, a formate, a pyruvate, a sugar and a phytate.
31. The process according to claim 21 , wherein the additive comprises trace elements.
32. The process according to claim 21 , wherein the additive comprises (1) one or more compounds selected from the group consisting of calcium formate, calcium acetate, calcium lactate, calcium gluconate, a carbohydrate, a fatty acid, a amino acid, a lactate, a maleate, a formate, a sugar, a pyruvate and a phytate and (2) a bacterial growth factor selected from the group consisting of a yeast extract, a peptone, an aspartate, a glutamate and trace elements.
33. The process according to claim 21 , where the additive comprises (a) a calcium compound, (b) one or more of an organic compound and a phosphor compound, (c) trace elements and (d) one or more of a yeast extract, a peptone, an aspartate, and a glutamate.
34. The process according to claim 21 , wherein the weight ratio bacterial material:additive of the particulate healing agent is in the range of 1:10,000-1:1,000,000.
35. The process according to claim 21 , wherein the coated particles comprise at least 50 wt. % bacterial material and additive, relative to the total weight of the coated particles.
36. The process according to claim 21 , wherein the coated particles have mean dimensions in the range of 0.2-4 mm.
37. The process according to claim 21 , wherein the coated particles have a coating thickness in the range 5 μm-2 mm.
38. The process according to claim 21 , wherein the coating comprises an epoxy based (co)polymer.
39. The process according to claim 21 , wherein the coated particles have a mean particle hardness in the range of 3-9 according to Mohs scale.
40. The process according to claim 21 , wherein the weight ratio of the cement starting materials to the particulate healing agent is in the range of 2,000:1-20:1.
41. The process according to claim 21 , wherein the weight ratio of the cement starting materials to the bacterium is in the range of 1.10 6 :1-1.10 8 :1.