Sprayable strain hardening brittle matrix composites with fire-resistance and high ductility

Patent metadata

Field	Value
Publication number	US-9260347-B2
Application number	US-201514667821-A
Country	US
Kind code	B2
Filing date	Mar 25, 2015
Priority date	Mar 25, 2014
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A formulation of a spray applied fire-resistive engineered cementitious composite (SFR-ECC) which is made by addition of polymeric fibers, vermiculite, bonding agent and lightweight aggregates to cement and water. The SFR-ECC formulation is made in wet cement and can be spray-applied. The durable SFR-ECC exhibits thermal conductivities sufficient for fire resistance with increased tensile ductility and impact resistance.

First claim

What is claimed is:

1. A fiber reinforced cement-based composite comprising:
a cement material;
a water having a water to cement weight ratio greater than one thereby forming a cement matrix;
an air void structure system having air pores in the range of 0.2-0.7 mm formed due to air entrainment within said cement matrix;
a lightweight aggregate each having a diameter less than 200 μm, said lightweight aggregate having air or inert gas disposed within said aggregate, a density of said aggregate ranging from 200-900 kg/m 3 , a volume of said aggregate ranging from 15% to 50% of the total volume of the composite;
short randomly distributed fibers having a volume fraction of less than 4% by volume fraction, said fibers having a diameter between 10 and 50 μm and a length between 6 and 12 mm;
super fine grade vermiculite with particle size less than 1.5 mm, a vermiculite to cement weight ratio being 20 to 40% of cement;
a bonding agent having a bonding agent to cement weight ratio lower than 10%; and
a superplasticizer and viscosity modifying agent for rheology control.

2. The composite according to claim 1 wherein said composite having dry density of 352-1280 kg/m 3 .

3. The composite according to claim 2 wherein said composite having dry density of 400-800 kg/m 3 .

4. The composite according to claim 1 wherein said composite having tensile strength of 0.5-3 MPa.

5. The composite according to claim 1 wherein said composite having tensile strain capacity of at least 0.75%.

6. The composite according to claim 1 wherein said composite is sprayable.

7. The composite according to claim 1 wherein said composite is castable.

8. The composite according to claim 1 wherein said composite is hand trowelable.

9. The composite according to claim 1 wherein said composite can be shaped using a tile-saw.

10. The composite according to claim 1 wherein said composite can be shaped using a hand saw.

11. The composite according to claim 1 wherein said composite can be shaped using a craft knife.

12. The composite according to claim 1 wherein said fibers comprise polyvinyl alcohol fibers.

13. The composite according to claim 1 wherein said fibers comprise high tenacity polypropylene fibers.

14. The composite according to claim 1 wherein said bonding agent comprises acrylic latex polymer.

15. The composite according to claim 1 wherein said lightweight aggregate comprises inert hollow microspheres.

Assignees

• Univ Michigan

Inventors

• Li Victor C
• Zhang Qian

Classifications

• C04B28/02 Primary

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B28/28 Primary

  containing organic polyacids, e.g. polycarboxylate cements {, i.e. ionomeric systems} · CPC title

• C04B2111/00146

  Sprayable or pumpable mixtures · CPC title

• C04B2111/00068

  Mortar or concrete mixtures with an unusual water/cement ratio · CPC title

• Y02A30/30

  in transportation, e.g. on roads, waterways or railways · CPC title