Shotcrete composition

Patent metadata

Field	Value
Publication number	US-12534405-B2
Application number	US-202017604501-A
Country	US
Kind code	B2
Filing date	Apr 17, 2020
Priority date	Apr 18, 2019
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A shotcrete composition comprising a) a cementitious binder; b) an ettringite formation controller comprising (i) a glyoxylic acid condensate and/or a glyoxylic acid adduct; and c) an alkali-free, aluminum-based shotcrete accelerator. The invention further relates to a process comprising providing a cementitious composition comprising a) a cementitious binder, and b) an ettringite formation controller comprising (i) a glyoxylic acid condensate and/or a glyoxylic acid adduct; admixing an alkali-free, aluminum-based shotcrete accelerator to the cementitious composition to obtain a shotcrete composition; and applying the shotcrete composition onto a surface to obtain a shotcrete structure and allowing the shotcrete structure to harden. The invention also relates to a hardened shotcrete structure obtained by this process.

First claim

The invention claimed is:

1 . A shotcrete composition comprising:
a) a cementitious binder; b) an ettringite formation controller comprising (i) an amine-glyoxylic acid condensate; and c) an alkali-free, aluminum-based shotcrete accelerator selected from aluminum salts, aluminum complexes, aluminum hydroxides, and mixtures thereof; wherein the shotcrete composition has a strength as measured by a penetration resistance force at 6 minutes to 6 hours.

2 . The composition according to claim 1 , wherein the amine-glyoxylic acid condensate is at least one of a melamine-glyoxylic acid condensate, a urea-glyoxylic acid condensate, a melamine-urea-glyoxylic acid condensate, or a polyacrylamide-glyoxylic acid condensate.

3 . The composition according to claim 1 , wherein the ettringite formation controller additionally comprises (ii) a carbonate source.

4 . The composition according to claim 3 , wherein the carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 gL −1 or more, organic carbonates, and mixtures thereof.

5 . The composition according to claim 4 , wherein the inorganic carbonate is selected from the group consisting of sodium carbonate, lithium carbonate and magnesium carbonate; and the organic carbonate is selected from the group consisting of ethylene carbonate and propylene carbonate.

6 . The composition according to claim 1 , wherein the ettringite formation controller additionally comprises (iii) a component selected from
polycarboxylic acids or salts thereof whose milliequivalent number of carboxyl groups is 5.00 meq/g or higher; and α-hydroxy carboxylic acids or salts thereof.

7 . The composition according to claim 6 , wherein the polycarboxylic acid is selected from phosphonoalkyl carboxylic acids, amino carboxylic acids, and polymeric carboxylic acids.

8 . The composition according to claim 6 , wherein the component is selected from:
polycarboxylic acids or salts thereof whose milliequivalent number of carboxyl groups is 5.00 to 15.00 meq/g; and α-hydroxy carboxylic acids or salts thereof.

9 . The composition according to claim 1 , wherein the cementitious binder is selected from Portland cement, calcium aluminate cement, sulfoaluminate cement, or combinations thereof.

10 . The composition according to claim 1 , wherein the composition additionally comprises a latent hydraulic binder or a pozzolanic binder, or mixtures thereof.

11 . The composition according to claim 1 , additionally comprising a dispersant.

12 . The composition according to claim 11 , wherein the dispersant is selected from the group of
comb polymers having a carbon-containing backbone to which are attached pendant cement-anchoring groups and polyether side chains, non-ionic comb polymers having a carbon-containing backbone to which are attached pendant hydrolysable groups and polyether side chains, the hydrolysable groups upon hydrolysis releasing cement-anchoring groups, sulfonated melamine-formaldehyde condensates, lignosulfonates, sulfonated ketone-formaldehyde condensates, sulfonated naphthalene-formaldehyde condensates, phosphonate containing dispersants, phosphate containing dispersants, and mixtures thereof.

13 . The composition according to claim 1 , wherein the composition exhibits superior early strength, as compared to the composition without b) ettringite formation controller comprising (i) an amine-glyoxylic acid condensate.

14 . A process comprising:
providing a cementitious composition comprising a) a cementitious binder, and b) an ettringite formation controller comprising (i) an amine-glyoxylic acid condensate; admixing an alkali-free, aluminum-based shotcrete accelerator selected from aluminum salts, aluminum complexes, aluminum hydroxides, and mixtures thereof to the cementitious composition to obtain a shotcrete composition; and applying the shotcrete composition onto a surface to obtain a shotcrete structure and allowing the shotcrete structure to harden.

15 . A hardened shotcrete structure obtained by the process according to claim 14 .

Assignees

• Construction Research & Technology Gmbh

Inventors

• Mitkina Tatiana
• Dengler Joachim

Classifications

• C04B2103/10

  Accelerators; Activators · CPC title

• C04B24/126

  Urea · CPC title

• C04B24/04

  Carboxylic acids; Salts, anhydrides or esters thereof · CPC title

• C04B28/04 Primary

  Portland cements · CPC title

• C04B24/2647

  containing polyether side chains · CPC title