NZ569158A

NZ569158A - Building panels and cementitious mixtures for building panels comprising vermiculite

Info

Publication number: NZ569158A
Application number: NZ569158A
Authority: NZ
Inventors: Michael Albert Anderson
Original assignee: Michael Albert Anderson
Priority date: 2005-11-15
Filing date: 2006-11-15
Publication date: 2010-04-30
Also published as: AU2006315076A1; WO2007056805A1

Abstract

Disclosed is a cementitious mixture including, in volume for volume proportions: cement 9.5% to 20%; fly ash 2% to 10%; bonding agent 1% to 2%; water proofing 0% to 2%; vermiculite 78% to 40%; and the balance being water 9.5% to 26%.

Description

New Zealand Paient Spedficaiion for Paient Number 569158 wo 2007/056805 pct/au2006/001710 Building Panels and Cementitious Mixtures for Building Panels FIELD OF INVENTION THIS INVENTION relates to building panels and to cementitious mixtures for building panels.

The invention has particular application to building panels which have a high fire, acoustic or thermal insulation rating and/or are relatively light-weight. However, the invention is not limited to this field of use.

In the art, the terms "cement" and "concrete" are sometimes used interchangeably. In this specification, unless the context requires otherwise, the term "cement" is used to refer to the 10 powdered constituents when mixed together prior to being activated to form concrete, and the term "concrete" is used to refer to cement after the addition of water to make it set as well as the material once it has set.

BACKGROUND ART Cementitious mixtures are known using ingredients which increase the fire, sound and/or 15 insulation ratings in product made from such mixtures. It is normally difficult to increase ratings for all three parameters of fire, sound and insulation together.

The present invention aims to provide building panels and cementitious mixtures for building panels alleviate at least one of the problems of the prior art, or at least provide a cost effective alternative to existing panels and mixtures for panels. Other aims and advantages of the 20 invention may become apparent from the following description.

DISCLOSURE OF THE INVENTION With the foregoing in view, the present invention in one aspect resides broadly in a cementitious mixture including the constituents in volume for volume proportions: cement 9.5% to 20%; fly ash 2% to 10%; bonding agent 1% to 2% water proofing 0% to 2% vermiculite 78% to 40% and WO 2007/056805 PCT/AU2006/001710 the balance being water 9.5% to 26%.

More preferably, the cementitious mixture includes the constituents in volume for volume proportions: cement 10% to 20%; fly ash 2% to 10%; bonding agent 1 % to 2% water proofing 0% to 2% vermiculite 59% to 40% and the balance being water 28% to 26%.

It can be seen that for increased proportions of cement, fly ash, bonding agent and water proofing, the proportion of vermiculate decreases in the formulation. Preferably, the cementitious mixture includes the constituent's in volume for volume proportions: cement 9.5% to 13%; fly ash 4.75% to 6.5%; bonding agent 1.1% to 1.7% waterproofing 1.1% to 1.7% vermiculite 57% to 53% and the balance being water 26.55% to 24.1%.

Preferably, particularly where the lower proportions of vermiculite are used, sand is included up to 6.5%. Additionally, a fibrous reinforcing material may be added if desired.

More preferably, the cementitious mixture includes the constituents in volume for volume proportions: cement 11% to 12%; fly ash 5% to 6%; 569158 bonding agent 1.3% to 1.5% waterproofing 1.3% to 1.5% vermiculite 56% to 54% and the balance being water 25.4% to 25%.

The bonding agent is preferably selected from polyvinyl acetate resins sometimes used in cementitious mixtures. The water proofing is preferably selected from admixtures known to provide "internal" or "integral" waterproofing agents for cementitious mixtures, such as alkali metal salts of long chain fatty acids. However, it will be appreciated that alternative forms of waterproofing agent may be substituted for such forms.

In another aspect, the present invention resides broadly in a product formed from a cementitious mixture as herein described. In a preferred form, the product is a panel formed to a size commensurate with panel sizes used in building construction.

BRIEF DESCRIPTION OF THE EXAMPLES In order that the invention may be more readily understood and put into practical effect, reference will now be made to two examples which illustrate the invention in two preferred forms. There were two types of cementitious mixtures designated the terra "mid-weight" and "light-weight". However, it will be appreciated that such terms are for convenience of reference only and are not to be taken as necessarily describing such qualities of the mixtures or the products formed from such mixtures.

DETAILED DESCRIPTION OF THE EXAMPLES EXAMPLE 1 - Mid-Weight Cementitious Mixture A first example was formulated using the following constituents: 3.5 litres water; 8 litres vermiculite; 2 litres cement; 1 litre fly ash; WO 2007/056805 PCT/AU2006/001710 1 litre sand; 250 millilitres bonding agent; and 250 millilitres water proofing.

The bonding agent was a polyvinyl acetate "white glue" admixture for cementitious mixtures and the waterproofing agent was "Duxatite Clear" from Davco Construction Materials Pty Ltd, believed to be an amnioniacal solution of one or more long chain fatty acid sodium salts. The mixture was blended until substantially homogeneous and poured into a panel mould to form a panel approximately 35 millimetres thick and allowed to set.

EXAMPLE 2 - Light-Weight Cementitious Mixture A second example was formulated using the following constituents: 4.5 litres water; 12 litres vermiculite; 2 litres cement; 1 litre fly ash; 500 millilitres bonding agent; and 500 millilitres water proofing.

The bonding agent and waterproofing were the same materials used in Example 1. The mixture was blended until substantially homogeneous and poured into a panel mould to form a panel approximately 35 millimetres thick and allowed to set.

EXAMPLE 3 — Heavy-Weight Cementitious Mixture A third example was formulated using the following constituents: 1 litres water; 6 litres vermiculite; 3 litres cement; 1.5 litre fly ash;

Claims

WO 2007/056805 569158 PCT/AU2006/001710 -5- 200 millilitres bonding agent; and 200 millilitres water proofing. The bonding agent and waterproofing were the same materials used in Examples 1 and 2. The mixture was blended until substantially homogeneous and poured into a panel mould 5 to form a panel approximately 35 millimetres thick and allowed to set. The building panels formed in accordance with the invention as described in Examples 1, 2 and 3 were found to be structurally sound, dimensionally stable and lighter than concrete panels of the same volume. The panel from Example 2 was lighter than the panel of Example 1. The panel from Example 3 was heavier than the panels of Examples 1 and 2. It is believed that 10 cementitious mixtures according to the invention may include other additives or admixtures known in the art to take advantage of their respective functional qualities. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in other forms and combinations thereof within the broad scope and ambit of the invention as defined by the 15 following claims. WO 2007/056805 PCT/AU2006/001710 -6-CLAIMS

1. A cementitious mixture including the constituents in volume for volume proportions: cement 9.5% to 20%; fly ash 2% to 10%; bonding agent 1% to 2% water proofing 0% to 2% vermiculite 78% to 40% and the balance being water 9.5% to 26%.

2. The cementitious mixture according to constituents in volume for volume proportions: cement 10% to 20%; fly ash 2% to 10%; bonding agent 1% to 2% water proofing 0% to 2% vermiculite 59% to 40% and the balance being water 28% to 26%. Claim 1, wherein said mixture includes the

3. The cementitious mixture according to Claim 1 or Claim 2, wherein said mixture includes the constituents in volume for volume proportions: cement 9.5% to 13%; fly ash 4.75% to 6.5%; bonding agent 1.1% to 1.7%

WO 2007/056805 PCT/AU2006/001710 -7- waterproofing 1.1% to 1.7% vermiculite 57% to 53% and the balance being water 26.55% to 24.1%. 5 4. A cementitious mixture according to any one of the preceding claims, wherein sand is included up to 6.5%.

5. The cementitious mixture according to any one of the preceding claims, wherein the mixture includes the constituents in volume for volume proportions: 10 cement 11 % to 12%; fly ash 5% to 6%; bonding agent 1.3% to 1.5% waterproofing 1.3% to 1.5% vermiculite 56% to 54% and 15 the balance being water 25.4% to 25%. Dated this 15th day of November 2006. MICHAEL ALBERT ANDERSON 20 By his Patent Attorneys AHEARNFOX