High durability engineered cementitious composites

Patent metadata

Field	Value
Publication number	US-2024132770-A1
Application number	US-202218046259-A
Country	US
Kind code	A1
Filing date	Oct 13, 2022
Priority date	Oct 13, 2022
Publication date	Apr 25, 2024
Grant date	—

Abstract

An engineered cementitious composite (ECC) has a tensile strain capacity ranging from 8.6 to 12.5% and includes a cement precursor, unprocessed desert sand, and polymer fibers. The polymer fibers may be ultra-high molecular weight polyethylene fibers, polypropylene fibers, or a combination thereof. A method of preparing an ECC structure includes providing a cementitious precursor mixture including a cement precursor and unprocessed desert sand, introducing water into the cementitious precursor mixture to form a cement slurry, and adding polymer fibers to the cement slurry. The polymer fibers may be ultra-high molecular weight polyethylene fibers, polypropylene fibers, or a combination thereof. Then, the method includes forming a structure with the cement slurry and curing the cement slurry.

First claim

1 . An engineered cementitious composite (ECC) comprising:
a cement precursor; unprocessed desert sand having an average particle size ranging from 200 to 600 micrometers (μm); and polymer fibers selected from the group consisting of ultra-high molecular weight polyethylene fibers, polypropylene fibers, and a combination thereof, wherein the ECC has a tensile strain capacity ranging from 8.6 to 12.5%.

2 . The ECC of claim 1 , wherein the cement precursor is included in an amount ranging from 14 to 40 wt %, based on a total weight of the ECC.

3 . The ECC of claim 1 , wherein the unprocessed desert sand is included in an amount ranging from 20 to 45 wt %, based on a total weight of the ECC.

4 . The ECC of claim 1 , wherein the polymer fibers comprise ultra-high molecular weight polyethylene fibers that are included in an amount ranging from 0.2 to 10 wt %, based on a total weight of the ECC.

5 . The ECC of claim 1 , wherein the cement precursor comprises calcium sulphoaluminate cement.

6 . The ECC of claim 1 , wherein the polymer fibers comprise ultra-high molecular weight polyethylene fibers and wherein the ultra-high molecular weight polyethylene fibers have an average diameter of about 16 to 30 μm and an average length of about 4 to about 20 mm.

7 . The ECC of claim 1 , wherein the polymer fibers are polypropylene fibers and are included in an amount ranging from 0.1 to 0.5 wt %, based on the total weight of the ECC.

8 . The ECC of claim 1 , wherein the polymer fibers are polypropylene fibers and wherein the polypropylene fibers have an average diameter of about 8 to 20 m and an average length of about 5 to about 15 mm.

9 . The ECC of claim 1 , further comprising crumb rubber in an amount of 0.1 to 2.0 wt %, based on a total weight of the ECC.

10 . The ECC of claim 9 , wherein the crumb rubber is superfine crumb rubber having an average particle size ranging from 75 to 150 microns.

11 . The ECC of claim 9 , wherein the crumb rubber is ultrafine crumb rubber having an average particle size of less than 75 microns.

12 . The ECC of claim 1 , further comprising volcanic ash in an amount ranging from 20 to 40 wt %, based on a total weight of the ECC.

13 . The ECC of claim 12 , wherein the volcanic ash comprises an average particle size ranging from 50 to 120 μm.

14 . The ECC of claim 12 , further comprising silica fume in an amount ranging from 3.0 to 6.0 wt %, based on a total weight of the ECC.

15 . The ECC of claim 1 , wherein the ECC has a tensile strength ranging from 6 to 9 MPa.

16 . A method of preparing an ECC structure comprising:
providing a cementitious precursor mixture comprising a cement precursor and unprocessed desert sand; introducing water into the cementitious precursor mixture to form a cement slurry; adding polymer fibers to the cement slurry, wherein the polymer fibers are selected from the group consisting of ultra-high molecular weight polyethylene fibers, polypropylene fibers, and a combination thereof; forming a structure with the cement slurry; and curing the cement slurry.

17 . The method according to claim 16 , wherein the cementitious precursor mixture further comprises one or more of fly ash, volcanic ash, silica fume, a crystalline capillary admixture, and crumb rubber.

18 . The method of claim 16 , wherein the ECC structure has a tensile strain capacity ranging from 8.6 to 12.5%.

19 . The method of claim 16 , wherein the cementitious precursor mixture includes the cement precursor in an amount ranging from 14 to 40 wt % and the unprocessed desert sand in an amount ranging from 20 to 45 wt %.

20 . A method of cementing a wellbore comprising:
forming a cement slurry comprising a cement precursor, unprocessed desert sand, polymer fibers, and water, wherein the polymer fibers are selected from the group consisting of ultra-high molecular weight polyethylene fibers, polypropylene fibers and a combination thereof; pumping the cement slurry to a location within the wellbore; and curing the cement slurry at the location to provide an engineered cementitious composite (ECC) structure, wherein the ECC has a tensile strain capacity ranging from 8.6 to 12.5%.

Assignees

• Saudi Arabian Oil Co
• Univ Michigan

Inventors

• Al Mehthel Mohammed
• Li Victor
• Zhu He
• Villette Thibault
• Nasser Waleed
• Vidal Oscar Salazar

Classifications

• C09K8/467 Primary

  containing additives for specific purposes · CPC title

• C04B7/323

  Calcium aluminosulfate cements, e.g. cements hydrating into ettringite · CPC title

• C04B14/068

  Specific natural sands, e.g. sea -, beach -, dune - or desert sand · CPC title

• C04B16/0633

  Polypropylene · CPC title

• C04B18/146

  Silica fume · CPC title