High Performance Fire Resistant Concrete Containing Hybrid Fibers and Nano Particles

Patent metadata

Field	Value
Publication number	US-2018237338-A1
Application number	US-201815899376-A
Country	US
Kind code	A1
Filing date	Feb 20, 2018
Priority date	Feb 22, 2017
Publication date	Aug 23, 2018
Grant date	—

Abstract

A high-workability, fire-resistant, anti-spalling concrete composition is provided. The concrete composition has a slump value of at least approximately 150 mm, a fire-resistant period of at least 4 hours, a compressive strength of at least 120 MPa at room temperature, and a compressive strength of at least 20 MPa at 700° C. The composition includes cement, fly ash, silica fume, aggregate particles having a particle size D90 of approximately 20 mm or less and superplasticizer. The composition includes fiber additives including steel fibers in an amount ranging between approximately 0.1% and approximately 0.4% by volume of the concrete composition and polypropylene fibers having a melting point of approximately 200° C. or less in an amount ranging between approximately 0.05% and 0.3% by volume of the concrete composition. Carbon nanotubes are also present in an amount ranging between approximately 0.1% and approximately 0.3% by volume of the concrete composition.

First claim

1 . A high-workability, fire-resistant, anti-spalling concrete composition having a slump value of at least approximately 150 mm, a fire-resistant period of at least 4 hours, a compressive strength of at least 120 MPa at room temperature, and a compressive strength of at least 20 MPa at 700° C., the composition comprising:
cement;
fly ash;
silica fume;
aggregate particles having a particle size D 90 of approximately 20 mm or less; and
superplasticizer;

the composition including fiber additives comprising steel fibers in an amount ranging between approximately 0.1% and approximately 0.4% by volume of the concrete composition and polypropylene fibers having a melting point of approximately 200° C. or less in an amount ranging between approximately 0.05% and 0.3% by volume of the concrete composition and further comprising carbon nanoparticles in an amount ranging between approximately 0.1% and 0.3% by volume of the concrete composition.

2 . The concrete composition of claim 1 , wherein the compressive strength at 700° C. is at least 28 MPa.

3 . The concrete composition of claim 1 , wherein steel fiber is coated with copper.

4 . The concrete composition of claim 1 wherein the water contact angle of the polypropylene fiber is less than 90 degrees.

5 . The concrete composition of claim 1 , wherein the carbon nanoparticles are carbon nanotube.

6 . The concrete composition of claim 1 , wherein the carbon nanoparticles are dispersed in a slurry.

7 . The concrete composition of claim 1 , wherein the polypropylene fibers have an average length greater than approximately 6 mm.

8 . The concrete composition of claim 1 , wherein the polypropylene fibers have a diameter less than approximately 42 microns.

9 . The concrete composition of claim 1 , wherein the steel fibers have an average length greater than approximately 13 mm.

10 . The concrete composition of claim 1 , wherein the steel fibers have a diameter of at least approximately 160 microns.

11 . The concrete composition of claim 1 , wherein the superplasticizer is a polycarboxylate-based superplasticizer.

Assignees

• Nano & Advanced Materials Inst Ltd

Inventors

• Fang Shuai
• Zhu Honggang
• Lam Yue Kee
• Sham Man Lung
• Poon Chi Sun
• Li Feng
• Ng Pui Lam

Classifications

• C04B24/283

  Polyesters · CPC title

• C04B20/1062

  Metals · CPC title

• C04B14/026 Primary

  of particular shape, e.g. nanotubes · CPC title

• C04B2201/52

  High compression strength concretes, i.e. with a compression strength higher than about 55 N/mm2, e.g. reactive powder concrete [RPC] · CPC title

• C04B14/48

  Metal · CPC title