Spraying uhpfrc for reinforcement and regeneration of pre-existing structures

Patent metadata

Field	Value
Publication number	US-2021380476-A1
Application number	US-201917282458-A
Country	US
Kind code	A1
Filing date	Oct 2, 2019
Priority date	Oct 3, 2018
Publication date	Dec 9, 2021
Grant date	—

Abstract

A method for reinforcing a structure comprising the following steps:preparation of UHPFRC comprising a cement precursor mix, of water, a fluidizing agent and metal fibers,transporting the UHPFRC by pumping to a suitable spray nozzle,spraying the mix onto a surface of the structure by the addition of a compressed air stream in the spray nozzle.

First claim

1 . A method for reinforcing a structure comprising the following steps:
preparing UHPFRC comprising a cement precursor mix, of water, a fluidizing agent and metal fibers comprising at least 2% by volume of concrete, transporting the UHPFRC by pumping to a spray nozzle, spraying the mixture onto a surface of the structure by the addition of a compressed air stream in the spray nozzle.

2 . The method as claimed in claim 1 , wherein the spraying is performed wet at a flow rate of between 2 and 10 m3/h.

3 . The method as claimed in claim 1 , wherein the spraying is performed wet by the addition of compressed air with a compressed air flow rate at the nozzle or gun of between 10 000 and 17 000 l/min.

4 . The method as claimed in claim 1 , wherein the spraying is performed wet by the addition of compressed air with an air pressure of between 5 and 11 bar.

5 . The method as claimed in claim 1 , wherein the metal fibers are made of high-strength steel.

6 . The method as claimed in claim 1 , wherein the UHPFRC has a metal fiber content of between 2 and 3.5% by volume of concrete.

7 . The method as claimed in claim 1 , wherein the cement precursor mix comprises between 700 and 1000 kg of cement per m3 of mix.

8 . The method as claimed in claim 1 , wherein the UHPFRC has a water/cement weight ratio of less than 0.25, preferably less than 0.20.

9 . The method as claimed in claim 1 , wherein the fibers have a greater mean dimension, for example a length, greater than 14 mm.

10 . A structure reinforced, repaired or regenerated according to the method of claim 1 , wherein the structure has at least one wall spray-coated with UHPFRC.

Assignees

• Soletanche Freyssinet

Inventors

• Huynh Tuong Alain
• Petit Bertrand
• Teply François
• Chaux Cédric-Olivier

Classifications

• C04B2111/72

  Repairing or restoring existing buildings or building materials · CPC title

• C04B14/48 Primary

  Metal · CPC title

• B05B7/0483

  with gas and liquid jets intersecting in the mixing chamber · CPC title

• B28C5/408

  by spraying fibres and binding material · CPC title

• C04B28/18

  containing mixtures of the silica-lime type · CPC title