Fiber reinforced cement

Patent metadata

Field	Value
Publication number	US-11325863-B2
Application number	US-201816634160-A
Country	US
Kind code	B2
Filing date	Jul 30, 2018
Priority date	Jul 28, 2017
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

Provided herein are fiber reinforced cementitious materials and mixtures with increased crack resistance. The cementitious materials and mixtures include a cement and at least one carbon fiber. Also provide is a fiber reinforced cementitious mortar that includes the fiber reinforced cementitious material to which at least one of water, an aggregate material or a chemical admixture is added.

First claim

What is claimed is:

1. A fiber reinforced cementitious material with increased crack resistance, consisting of:
a premixture of a microfine cement and carbon nanofibers or carbon microfibers or a combination thereof; and
water.

2. The fiber reinforced cementitious material of claim 1 , wherein the microfine cement is a microfine Portland cement.

3. The fiber reinforced cementitious material of claim 1 , wherein the carbon microfibers are milled carbon microfiber or chopped carbon microfibers or a combination thereof.

4. The fiber reinforced cementitious material of claim 3 , wherein the carbon nanofibers are each about 5 nanometers to about 150 nanometers in diameter and about 5 micrometers to about 200 micrometers in length.

5. The fiber reinforced cementitious material of claim 3 , wherein the carbon microfibers are each about 3 micrometers to 15 micrometers in diameter and ranges from less than 1 millimeter to greater than 15 millimeters in length.

6. The fiber reinforced cementitious material of claim 1 , wherein the carbon nanofibers or the carbon microfibers are 15% or less by weight of the microfine cement.

7. The fiber reinforced cementitious material of claim 1 , wherein the cementitious material has an increased resistance to cracking due to restrained drying shrinkage, bridges microcracks and delays formation of macro cracks, and has a high flexure strength, an increased compressive strength and an increased impact toughness.

8. The fiber reinforced cementitious material of claim 7 , wherein the cementitious material has an increased cracking resistance of at least 5,200% without loss to flexure strength, compressive strength or impact toughness.

9. A fiber reinforced mortar, consisting of:
the premixture of claim 1 ;
an aggregate material;
a chemical admixture; and
water.

10. The fiber reinforced mortar of claim 9 , wherein the aggregate material is sand, gravel or crushed stone or a combination thereof.

11. The fiber reinforced mortar of claim 9 , wherein the chemical admixture comprises a polycarboxylate high-range water reducer (HRWR) or a sucrose-based retarder or a combination thereof.

12. The fiber reinforced mortar of claim 11 , wherein the chemical admixture is 4% or less by weight of the microfine cement.

13. A fiber reinforced cementitious mixture with an increased resistance to cracking, consisting of:
a premixture of carbon nanofibers and a microfine cement at 15% or less by weight of the cement per the carbon nanofibers; and
at least one of water, an aggregate material or a chemical admixture.

14. The fiber reinforced cementitious mixture of claim 13 , wherein the microfine cement is a microfine Portland cement.

15. The fiber reinforced cementitious mixture of claim 14 , wherein the carbon nanofibers are each about 5 nanometers to about 150 nanometers in diameter and about 5 micrometer to about 200 micrometers in length.

16. The fiber reinforced cementitious mixture of claim 13 , wherein the cementitious mixture has an increased resistance to cracking of at least 5,200% without loss to flexure strength, compressive strength or impact toughness.

17. The fiber reinforced cementitious mixture of claim 13 , wherein the aggregate material is sand, gravel or crushed stone or a combination thereof.

18. The fiber reinforced cementitious mixture of claim 13 , wherein the chemical admixture comprises a polycarboxylate high-range water reducer (HRWR) or a sucrose-based retarder or a combination thereof.

19. The fiber reinforced cementitious mixture of claim 18 , wherein the chemical admixture is 4% or less by weight of the microfine cement.

Assignees

• Hogancamp Joshua
• Grasley Zachary
• Texas A & M Univ Sys

Inventors

• Hogancamp Joshua
• Grasley Zachary

Classifications

• C04B2111/34

  Non-shrinking or non-cracking materials · CPC title

• C04B28/04 Primary

  Portland cements · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C04B14/386

  Carbon (carbon nanotubes C04B14/026) · CPC title

• C04B20/1037

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title