Integrally waterproof fiber cement composite material

Patent metadata

Field	Value
Publication number	US-2021371338-A1
Application number	US-201917290648-A
Country	US
Kind code	A1
Filing date	Nov 6, 2019
Priority date	Nov 7, 2018
Publication date	Dec 2, 2021
Grant date	—

Abstract

Integrally waterproof fiber cement composite materials including interior and exterior fiber cement articles for building structures are disclosed. Fiber cement formulations include small percentages of silica fume and silanol. Formulations may additionally include a cementitious binder, silica, and a density modifier such as calcium silicate or perlite. Advantageously, the addition of preselected small percentages of silica fume and silanol has been discovered to yield waterproofness at substantially lower concentrations of silica fume and silanol than would be required to yield waterproofness when using either silica fume or silanol alone.

First claim

What is claimed is:

1 . An integrally waterproof fiber cement composite material, comprising:
between 25% and 29% by weight of a cementitious binder; between 50% and 60% by weight of silica; between 6.5% and 7.5% by weight of cellulose fibers, wherein the fibers have surfaces that are treated with silanol in a pre-dispersed solution, the silanol having a dry weight less than 1% of the dry weight of the cellulose fibers; between 2.5% and 3.5% by weight of alumina; between 5% and 6% by weight of a density modifier comprising at least one of calcium silicate and perlite; and between 0.25% and 1% by weight of silica fume having a particle size smaller than 150 μm.

2 . The integrally waterproof fiber cement composite material of claim 1 , wherein the silanol in the pre-dispersed solution have a dry weight equal to approximately 0.5% of the dry weight of the cellulose fibers.

3 . The integrally waterproof fiber cement composite material of claim 1 , wherein the integrally waterproof fiber cement composite material includes approximately 0.5% by weight of silica fume.

4 . The integrally waterproof fiber cement composite material of claim 1 , wherein the integrally waterproof fiber cement composite material is an interior board.

5 . The integrally waterproof fiber cement composite material of claim 1 , wherein the integrally waterproof fiber cement composite material is an exterior cladding.

6 . The integrally waterproof fiber cement composite material of claim 1 , wherein the integrally waterproof fiber cement composite material is sufficiently waterproof to prevent droplet formation when exposed to hydrostatic pressure from a 2″ wide×20″ tall column of water for 48 hours.

7 . A waterproof fiber cement composite material formulation comprising:
a cementitious hydraulic binder; silica; a pozzolanic material, wherein the pozzolanic material comprises between 0.25% and 2% of the dry weight of the material formulation; and cellulose fibers, at least some of the cellulose fibers having surfaces that are at least partially treated with a sizing agent to make the surfaces hydrophobic, wherein the dry weight of the sizing agent is between 0.25% and 2% of the weight of the cellulose fibers.

8 . The formulation of claim 7 , wherein the pozzolanic material comprises silica fume.

9 . The formulation of claim 7 , wherein the pozzolanic material comprises approximately 0.5% of the dry weight of the material formulation.

10 . The formulation of claim 7 , wherein the sizing agent comprises a silanol solution.

11 . The formulation of claim 10 , wherein the silanol solution comprises a dispersant.

12 . The formulation of claim 7 , wherein the dry weight of the sizing agent is approximately 0.5% of the weight of the cellulose fibers.

13 . The formulation of claim 7 , further comprising a density modifier.

14 . The formulation of claim 13 , wherein the density modifier comprises at least one of perlite and calcium silicate.

15 . The formulation of claim 7 , wherein the formulation, when used to form a fiber cement composite material, is sufficiently waterproof to prevent droplet formation when exposed to hydrostatic pressure from a 2″ wide×20″ tall column of water for 48 hours

16 . A method of manufacturing a waterproof fiber cement composite material, the method comprising:
mixing cellulose fibers with a silanol solution, wherein the silanol solution comprises an amount of silanol between 0.25% and 2% of the dry weight of the cellulose fibers; preparing a formulation comprising a cementitious hydraulic binder and silica; adding to the formulation the mixed cellulose fibers and silanol solution; adding to the formulation a quantity of silica fume, wherein the silica fume comprises between 0.25% and 2% of the dry weight of the formulation; and curing the formulation for a time sufficient to cause the material to set.

17 . The method of claim 16 , wherein the cellulose fibers are mixed with the silanol solution for between 1 and 10 minutes before being added to the formulation.

18 . The method of claim 16 , wherein the silanol solution comprises a dispersant.

19 . The method of claim 16 , wherein the formulation further comprises a density modifier comprising at least one of perlite and calcium silicate.

20 . The method of claim 16 , further comprising, prior to curing the formulation, forming the formulation into one or more substantially planar articles using a Hatschek process.

21 . The method of claim 20 , wherein the one or more substantially planar articles comprise an interior board.

22 . The method of claim 20 , wherein the one or more substantially planar articles comprise an exterior cladding.

23 . The method of claim 16 , wherein the cured formulation is sufficiently waterproof to prevent droplet formation when exposed to hydrostatic pressure from a 2″ wide×20″ tall column of water for 48 hours.

24 . An integrally waterproof fiber cement composite material, comprising:
between 35% and 39% by weight of a cementitious binder; between 40% and 50% by weight of silica; between 7.75% and 8.75% by weight of cellulose fibers, wherein the fibers have surfaces that are treated with silanol in a pre-dispersed solution, the silanol molecules having a dry weight less than 1% of the dry weight of the cellulose fibers; between 2.5% and 3.5% by weight of alumina; between 5% and 6% by weight of a density modifier comprising at least one of calcium silicate and perlite; and between 0.25% and 1% by weight of silica fume having a particle size smaller than 150 μm.

25 . The integrally waterproof fiber cement composite material of claim 24 , wherein the silanol in the pre-dispersed solution has a dry weight equal to approximately 0.5% of the dry weight of the cellulose fibers.

26 . The integrally waterproof fiber cement composite material of claim 24 , wherein the integrally waterproof fiber cement composite material includes approximately 0.5% by weight of silica fume.

27 . The integrally waterproof fiber cement composite material of claim 24 , wherein the integrally waterproof fiber cement composite material is an interior board.

28 . The integrally waterproof fiber cement composite material of claim 24 , wherein the integrally waterproof fiber cement composite material is an exterior cladding.

29 . The integrally waterproof fiber cement composite material of claim 24 , wherein the integrally waterproof fiber cement composite material is sufficiently waterproof to prevent droplet formation when exposed to hydrostatic pressure from a 2″ wide×20″ tall column of water for 48 hours.

30 . A fiber cement article comprising:
a first major face; a second major face opposite the first major face; and an intermediate portion disposed between the first major face and the second major face, the intermediate portion comprising:
a plurality of laminated layers of fiber cement; and
one or more pigmented layers disposed between adjacent layers of the plurality of laminated layers, the one or more pigmented layers having a different color relative to the plurality of laminated layers.

31 . The fiber cement article of claim 30 , wherein the one or more pigmented layers comprise particles of a pigment having an average particle size smaller than approximately

Assignees

• Hardie James Technology Ltd

Inventors

• Dones Noel
• Naji Basil
• Luo Caidian

Classifications

• Y02W30/91

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

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title

• E04F13/14

  stone or stone-like materials, e.g. ceramics {concrete,}; of glass {or with an outer layer of stone or stone-like materials or glass (E04F13/0864 takes precedence; producing shaped elements from concrete, ceramic compositions or other stone-like materials B28B; prefabricated panels in general E04C2/00)} · CPC title

• C04B40/0046

  characterised by their processing, e.g. sequence of mixing the ingredients when preparing the premixtures · CPC title

• C04B20/1051 Primary

  Organo-metallic compounds; Organo-silicon compounds, e.g. bentone · CPC title