Polymer irradiation in cement paste formation

Patent metadata

Field	Value
Publication number	US-10947158-B2
Application number	US-201816011831-A
Country	US
Kind code	B2
Filing date	Jun 19, 2018
Priority date	Jun 19, 2018
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

Devices, systems, and methods of the present disclosure are generally directed to building material including particles of a polymer in an irradiated form, a cement including calcium oxide, and at least one additive including silicon dioxide. In cement paste formed from a mixture of these components, the polymer in the irradiated form may decrease porosity as compared to porosity of cement paste formed without the polymer, and a combination of the silicon dioxide and the calcium oxide may form high-density phases in the cement paste. With these characteristics, such cement paste may exhibit at least the same compressive strength as cement paste formed from the cement by itself. Thus, in certain instances, the particles of the polymer may displace a portion of the cement in a manner that maintains compressive strength while facilitating reduction of greenhouse gas emissions associated with cement paste formation.

First claim

What is claimed is:

1. A method of forming a building material, the method comprising:
receiving particles of a polymer in a non-irradiated form, the polymer having a semi-crystalline structure;
irradiating the particles of the polymer from the non-irradiated form to an irradiated form with a dose of gamma radiation increasing crystallinity and crosslinking of the polymer from the non-irradiated form to the irradiated form; and
combining the particles of the polymer in the irradiated form with at least a cement, and at least one additive to form a mixture, the cement including calcium oxide, and the at least one additive including silicon dioxide.

2. The method of claim 1 , wherein the dose of gamma radiation is greater than about 100 kGy and less than about 150 kGy.

3. The method of claim 1 , wherein irradiating the particles of the polymer includes introducing the dose of the gamma radiation to the particles of the polymer at a rate of 58 Gy/min.

4. The method of claim 1 , wherein the at least one additive further includes alumina.

5. The method of claim 1 , wherein the at least one additive includes silica fume, fly ash, or a combination thereof.

6. The method of claim 1 , wherein the cement is ordinary Portland cement.

7. The method of claim 1 , wherein the polymer is polyethylene terephthalate.

8. The method of claim 1 , wherein the particles of the polymer are greater than about 1 percent of a total mass of the mixture in an anhydrous form and less than about 2 percent of the total mass of the mixture in the anhydrous form.

9. The method of claim 1 , wherein receiving the particles of the polymer includes receiving a stock material and mechanically separating the particles of the polymer from other components in a stream of stock material.

10. The method of claim 1 , wherein receiving the particles of the polymer includes mechanically reducing an average particle size of the particles of the polymer.

11. The method of claim 1 , further comprising hydrating the mixture to form a cement paste.

12. The method of claim 11 , wherein hydrating the mixture to form the cement paste includes adding water to the mixture in a predetermined volumetric ratio with the cement.

13. The method of claim 11 , further comprising maintaining substantially constant moisture content in the cement paste during a curing period following formation of the cement paste.

14. The method of claim 11 , further comprising exposing the cement paste to a polar solvent following a predetermined curing period.

15. A building material comprising:
a cement including calcium oxide;
at least one additive including silicon dioxide; and
particles of a polymer, the particles of the polymer in a non-irradiated form having a semi-crystalline structure, the particles of the polymer configured for irradiation from the non-irradiated form to an irradiated form with a dose of gamma radiation, the particles of the polymer in the irradiated form having crystallinity and crosslinking greater than respective crystallinity and crosslinking of the polymer in the non-irradiated form, wherein the at least one additive and the particles of the polymer in the irradiated form are dispersed in the cement in a mixture, wherein the crystallinity of the irradiated form of the polymer is at least about 15 percent greater than the crystallinity of the polymer in the non-irradiated form.

16. The build material of claim 15 , wherein the cement is ordinary Portland cement.

17. The build material of claim 15 , wherein the at least one additive further includes alumina.

18. The build material of claim 15 , wherein the at least one additive includes silica fume, fly ash, or a combination thereof.

Assignees

• Massachusetts Inst Technology

Inventors

• Buyukozturk Oral
• Short Michael Philip
• Schaefer Carolyn E
• Ortega Michael
• White Anne E
• Kupwade-Patil Kunal

Classifications

• C04B28/04

  Portland cements · CPC title

• C04B24/283

  Polyesters · CPC title

• Y02W30/91

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

• C08G63/88

  Post-polymerisation treatment · CPC title

• C04B7/02

  Portland cement · CPC title