Polarity-enhanced ductile polymer fibers for concrete micro-reinforcement

Patent metadata

Field	Value
Publication number	US-2017190616-A1
Application number	US-201514983771-A
Country	US
Kind code	A1
Filing date	Dec 30, 2015
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

Provided are cementitious mixtures and processes for reinforcing a cementitious matrix. In one form of the process for reinforcing a cementitious matrix includes the steps of mixing a mineral cement and one or more populations of synthetic, low-crystallinity copolymer microfibers.

First claim

What is claimed is:

1 . A cementitious mixture, comprising:
a mineral cement; and synthetic, low-crystallinity copolymer microfibers.

2 . The cementitious mixture of claim 1 , which is a wet or a dry mixture.

3 . The cementitious mixture of claim 1 , which is a cured concrete.

4 . The cementitious mixture of claim 1 , wherein the synthetic, low-crystallinity copolymer of the microfibers has a crystallinity of from about 1% to about 60%.

5 . The cementitious mixture of claim 1 , wherein the synthetic, low-crystallinity copolymer microfibers have a ductility greater than about 50%, as measured by strain to failure.

6 . The cementitious mixture of claim 1 , wherein the synthetic, low-crystallinity copolymer is a random or non-random ethylene or propylene copolymer comprising from about 0.5 mol % to about 25 mol % of one of ethylene or propylene monomeric units, and from about 75 mol % to about 99.5 mol % of the other.

7 . The cementitious mixture of claim 1 , wherein the microfibers have exposed polar groups having chemical affinity with minerals present in curing or cured cementitious mixtures.

8 . The cementitious mixture of claim 7 , wherein the low-crystallinity copolymer comprises repeating units of at least two different monomer compounds, at least one of which monomer compounds having said polar groups.

9 . The cementitious mixture of claim 8 , wherein the monomer compounds having said polar groups are derived from alpha, beta-unsaturated carboxylic acids or anhydrides, or unsaturated organic sulfonic acids, or their salts or ester derivatives.

10 . The cementitious mixture of claim 7 , wherein the copolymer is an ionomer.

11 . The cementitious mixture of claim 1 , in which the copolymer of the microfibers is lightly cross-linked after formation of the microfibers.

12 . The cementitious mixture of claim 1 , wherein said microfibers have diameters of less than about 1 mm and aspect ratios from about 5:1 to about 50:1.

13 . The cementitious mixture of claim 1 , further comprising one or more of sand, fly ash, fine and/or coarse aggregates, blast furnace slag, pozzolans, fumed silica, wetting agents, air entrainers, air detrainers, corrosion inhibitors, set accelerators or set retarders.

14 . The cementitious mixture of claim 1 , wherein the synthetic, low-crystallinity copolymer microfibers comprise a first population of microfibers formed from a first synthetic, low-crystallinity copolymer and a second population of microfibers formed from a second synthetic, low-crystallinity copolymer, different from said first copolymer.

15 . A cementitious mixture, comprising:
a mineral cement; and microfibers which comprise a first population of microfibers formed from at least a first synthetic, low-crystallinity copolymer and a second population of microfibers formed from a second synthetic, low-crystallinity copolymer, different from said first copolymer, wherein monomers forming said different copolymers are selected to provide different physical characteristics to each of said different synthetic, low-crystallinity copolymers.

16 . The cementitious mixture of claim 15 , wherein the different synthetic, low-crystallinity copolymers have different thermal characteristics.

17 . The cementitious mixture of claim 15 , wherein the different synthetic, low-crystallinity copolymers have different softening temperatures.

18 . The cementitious mixture of claim 17 , wherein the first synthetic, low-crystallinity copolymer and the second synthetic, low-crystallinity copolymer have softening temperatures which differ by at least about 10° C.

19 . The cementitious mixture of claim 15 , wherein the different synthetic, low-crystallinity copolymers have different ductilities, as measured by strain to failure.

20 . The cementitious mixture of claim 15 , which is a wet or a dry mixture.

21 . The cementitious mixture of claim 15 , which is a cured concrete.

22 . The cementitious mixture of claim 15 , wherein the synthetic, low-crystallinity copolymers of the microfibers each have a crystallinity of from about 1% to about 60%.

23 . The cementitious mixture of claim 15 , wherein the synthetic, low-crystallinity copolymer microfibers have differing ductilities, each greater than about 50%, as measured by strain to failure.

24 . The cementitious mixture of claim 15 , wherein the synthetic, low-crystallinity copolymers are different random or non-random ethylene or propylene copolymer comprising from about 0.5 mol % to about 25 mol % of one of ethylene or propylene monomeric units, and from about 75 mol % to about 99.5 mol % of the other.

25 . The cementitious mixture of claim 15 , wherein the microfibers have exposed polar groups having chemical affinity with minerals present in curing or cured cementitious mixtures.

26 . The cementitious mixture of claim 25 , wherein the low-crystallinity copolymers comprises repeating units of at least two different monomer compounds, at least one of which monomer compounds having said polar groups.

27 . The cementitious mixture of claim 26 , wherein the monomer compounds having said polar groups are derived from alpha, beta-unsaturated carboxylic acids or anhydrides, or unsaturated organic sulfonic acids, or their salts or ester derivatives.

28 . The cementitious mixture of claim 26 , wherein at least one copolymer is an ionomer.

29 . The cementitious mixture of claim 15 , in which at least one of the copolymers of the microfibers is lightly cross-linked after formation of the microfibers.

30 . The cementitious mixture of claim 15 , wherein said microfibers have diameters of less than about 1 mm and aspect ratios from about 5:1 to about 50:1.

31 . The cementitious mixture of claim 15 , further comprising one or more of sand, fly ash, fine and/or coarse aggregates, blast furnace slag, pozzolans, fumed silica, wetting agents, air entrainers, air detrainers, corrosion inhibitors, set accelerators or set retarders.

32 . A process for reinforcing a cementitious matrix, comprising adding polymeric microfibers comprising one or more synthetic, low-crystallinity copolymers to a cementitious premixture containing a mineral cement.

33 . The process of claim 32 , wherein the polymeric microfibers comprise at least a first population of microfibers formed from a first synthetic, low-crystallinity copolymer and a second population of microfibers formed from a second synthetic, low-crystallinity copolymer, different from said first copolymer, the monomers of each different copolymer being selected to provide different physical characteristics to each of said different synthetic, low-crystallinity copolymers.

34 . The process of claim 33 , wherein the different synthetic, low-crystallinity copolymers have different thermal characteristics.

35 . The process of claim 33 , wherein the different synthetic, low-crystallinity copolymers have different softening temperatures.

36 . The process of claim 35 , wherein the first synthetic, low-crystallinity copolymer and the second synthetic, low-crystallinity copolymer have softening temperatures which differ by at least about 10° C.

37 . The process of claim 33 , wherein the di

Assignees

• Furmanski Jevan
• Exxonmobil Res & Eng Co

Inventors

• Furmanski Jevan

Classifications

• C04B16/0616

  from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C04B16/0633 Primary

  Polypropylene · CPC title

• C04B16/0625

  Polyalkenes, e.g. polyethylene · CPC title

• C04B28/02 Primary

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B20/006

  Microfibres; Nanofibres · CPC title