Self-healing and durable cement paste, mortars, and concretes

Patent metadata

Field	Value
Publication number	US-2021094879-A1
Application number	US-201917048474-A
Country	US
Kind code	A1
Filing date	Apr 19, 2019
Priority date	Apr 19, 2018
Publication date	Apr 1, 2021
Grant date	—

Abstract

Admixture for cementitious building materials can provide a self-healing mechanism to improve material longevity. In certain embodiments, the admixture can include the combination of both a quicklime-based replacement for fine and coarse aggregates and an SCM replacement for OPC in standard mortar and concrete.

First claim

1 . A composition comprising:
standard mortar including an ordinary Portland cement (OPC), a supplementary cementitious material (SCM), fine aggregate and calcined lime, wherein a portion of the OPC of an original formulation has been replaced with the supplementary cementitious material (SCM) and a portion fine aggregate of the original formulation has been replaced with the calcined lime.

2 . The composition of claim 1 , wherein the standard mortar includes 7-31 wt % of OPC and 69-93 wt % of fine aggregate.

3 . The composition of claim 2 , wherein up to 30% of OPC is replaced with SCM.

4 . The composition of claim 2 , wherein up to 45% of fine aggregate is replaced with calcined lime.

5 . The composition of claims 1 , wherein the SCM includes volcanic ash, fly ash, granulated blast furnace slag, silica fume, metakaolin, rice husk ash, calcined clay, brick, cocciopesto, or other ceramic materials.

6 . A method of making an admixture for cementitious building materials comprising:
making calcined lime by calcining calcium carbonate at temperatures between from 600° C. and 1450° C.; crushing, grounding or milling and sieving the calcined lime; and retaining particles between 150 microns and 4 mm for admixture.

7 . The method of claim 6 , further comprising replacing fine aggregate with calcined lime up to 45% in standard mortar.

8 . The method of claim 6 , further comprising replacing OPC with SCM up to 30% in standard mortar.

9 . The method of claim 7 , wherein the standard mortar includes 7-31 wt % of OPC and 69-93 wt % of fine aggregate.

10 . The method of claim 6 , calcining calcium carbonate at temperatures between 600° C. and 750° C.

11 . The method of claim 6 , further comprising calcining calcium carbonate at temperatures over 1300° C.

12 . The method of claim 6 , wherein fine aggregate includes quartz or sand.

13 . A composition comprising:
concrete including an ordinary Portland cement (OPC), a supplementary cementitious material (SCM), fine aggregate, coarse aggregate and calcined lime, wherein a portion of the OPC of an original formulation has been replaced with the supplementary cementitious material (SCM) and a portion fine aggregate of the original formulation has been replaced with the calcined lime.

14 . The composition of claim 13 , wherein the concrete includes 7-31 wt % of OPC and 69-93 wt % of fine aggregate.

15 . The composition of claim 14 , wherein up to 30% of OPC is replaced with SCM.

16 . The composition of claim 13 , wherein up to 45% of fine aggregate is replaced with calcined lime.

17 . The composition of claim 13 , wherein up to 25% of coarse aggregate is replaced with calcined lime.

18 . The composition of claim 13 , wherein the SCM includes volcanic ash, fly ash, granulated blast furnace slag, silica fume, metakaolin, rice husk ash, calcined clay, brick, cocciopesto, or other ceramic materials.

19 . The method of claim 8 , wherein the standard mortar includes 7-31 wt % of OPC and 69-93 wt % of fine aggregate.

Assignees

• Massachusetts Inst Technology

Inventors

• Masic Admir
• Seymour Linda

Classifications

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• Y02P40/10

  Production of cement, e.g. improving or optimising the production methods; Cement grinding · CPC title

• C04B40/0675

  Mortars activated by rain, percolating or sucked-up water; Self-healing mortars or concrete · CPC title

• C04B28/10

  Lime cements or magnesium oxide cements · CPC title

• C04B28/04

  Portland cements · CPC title