NZ543573A - Translucent paving system - Google Patents

Abstract

A construction material is disclosed that includes a composite matrix (1) formed from a light-transmitting aggregate, such as glass fragments, bound in a light-transmitting binder resin. The binder resin is flexible once cured so that the composite matrix is flexible. A lighting system (5) that includes a building element (8) formed from the construction material with a light source (9) on one side and transmitting light through the building element is also disclosed.

Description

PATENTS FORM NO. 5 Fee No 4: $250.00 James & Wells ref: 44261/57 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 543573 Dated: 15 November 2005 Light-transmitting Construction Material I, Michael Ian Olsen, a New Zealand citizen of Conroy's Road, RD 1, Alexandra, New Zealand do hereby declare this invention to be described in the following statement: Intellectual Property Office of N.Z.

FEB 2007 RE C EIV E D Light-transmitting Construction Material Technical Field The present invention relates generally to construction materials.

In particular, the present invention relates to a light-transmitting construction material.

Background Art Various construction materials have been devised for paving, flooring, walls, and other building elements depending on the structural and aesthetic features required. For example, some materials offer good insulation, rigidity, strength, or flexibility while others may have particular aesthetic qualities.

The environmental and cost concerns arising from wastage of household materials has led to the increasing use of recycled materials in such building elements. This use helps to reduce waste while also offering new and unique features. For example, much research has been undertaken to explore various options for recycling the substantial quantity of waste glass produced by many modern societies.

One particular use of such recycled glass has been as an aggregate for use in paving, as is disclosed by Hyodo in Japanese Patent Application No 05239775. Hyodo describes a crushed glass aggregate embedded in epoxy resin to provide a construction material for paving or the like. The epoxy resin and glass aggregate is laid in a form to shape the paving, and the resin hardened by curing. The surface is sanded to remove any sharp edges of the glass. Hyodo thus describes a colourful, paving system that utilises waste glass and is sufficiently rigid (by virtue of the epoxy resin) to ensure structural strength. 2 A similar material is described by Roddis in United States Patent No. 6,887,922 and also involves the use of a waste glass aggregate bound in a resin matrix. Roddis describes a specific glass granule size range which provides the necessary structural rigidity and strength.

The utilisation of other recycled materials for aggregate is also well known. For example, Hesterman et al in United States Patent No. 5,693,413 describe the use of rubber and glass waste bound in a resin to provide a flexible material for use in various applications i.e. as a "...resilient block material for curbs, road markers, patio blocks, barriers and weights...".

The materials described by Hyodo, Hesterman et al and Roddis provide sufficient strength and rigidity while recycling waste materials though they are not designed to transmit light.

One material specifically intended to transmit light to provide transparent walls is described by Losonczi in PCT publication No. WO 03/097954. Losonczi describes a 15 building block constructed from optical fibres embedded in a cast material, e.g. concrete. The fibres extend from one side of the block to the other to transmit light through the block. The block is designed as a load carrying material for wall construction. However, while the Losonczi device may provide a transparent block it can be very expensive due to the structural integrity requirement and the use of 20 carefully positioned embedded optical fibres rather than inexpensive, irregular waste glass. Moreover, the Losonczi device must be pre-constructed before use and, due to the fibre alignment requirement, cannot be used as a flowable medium to fill a form.

It would thus be advantageous to provide a construction material having one or more of the following attributes: 3 - Simple construction, - Inexpensive constituent components, - Flowable and/or mouldable before curing, - Translucent or transparent, - Flexible.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency 10 of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be 15 attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is 20 used in relation to one or more steps in a method or process.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from 4 the ensuing description which is given by way of example only. Disclosure of Invention According to one aspect of the present invention there is provided a construction material including a composite matrix formed from a light-transmitting aggregate 5 bound in a light-transmitting binder resin.

Preferably the aggregate includes glass fragments though it will be appreciated that in some applications, non-opaque plastics, fibreglass or other fragments may be used. However, to avoid prolixity, reference herein will be made to the aggregate containing glass fragments though this should not be seen to be limiting.

Binder Resin Reference to a "binder resin" herein will be understood by one skilled in the art to be any flowable binder resin that solidifies when 'cured'. It will be appreciated that the binder resin may be 'cured' by heat, air exposure and/or evaporation, electrically or magnetically or electromagnetically though is preferably cured chemically by 15 combining with a curing agent.

According to one embodiment, the binder resin is flexible once cured such that the glass composite matrix is substantially flexible. A flexible material offers advantages for many applications. For example, the material may be pre-cast off-site for paving applications and then placed within framing or edging on-site, the flexible nature 20 permitting placement even with a certain degree of variation in size between the framing and pre-cast paving. Furthermore, a flexible material provides a greater degree of resilience to impact which can be beneficial for paving, flooring and the like.

Preferably the binder resin is substantially translucent.

In an alternative embodiment the binder resin may be substantially transparent.

As used herein the term "translucenC will be referred to as including both substantially transparent and substantially translucent and hereinafter should be considered accordingly.

Thus, by providing a glass composite matrix with translucent binder resin, light may be 5 transmitted therethrough.

In one embodiment the refractive indices of the aggregate and binder are substantially the same to minimise refractive effects of light when passing from the resin into the glass aggregate.

In one embodiment the binder resin may be a room temperature vulcanizing silicone 10 or polysiloxane.

Preferably the binder matrix is polydimethylsiloxane. Polydimethylsiloxane is a particularly useful binder that provides sufficient glass bonding properties as well as flexibility and durability.

In an alternative embodiment the binder resin may include one or more of: flexible 15 thermoplastic, natural or synthetic rubber elastomers, polyurethane or acrylic foam, flexible plastics, or any other light transmitting binder.

In some applications it may be necessary to dilute the binder resin to improve flowability and/or alter the matrix properties. Therefore in one embodiment the resin may be mixed with a diluent. It will be appreciated by one skilled in the art that typical 20 resin diluents may include mineral turpentine, ethanol or other organic solvents though these are exemplary only and should not be seen to be limiting.

Typical resins as aforementioned can be expensive and thus in one embodiment the resin may be mixed with a suitable bulking agent, e.g. a fine translucent powder, to reduce the volume of resin required to construct said matrix. 6 It will be appreciated that translucent epoxy acrylic resins may be used as a binder resin though they are typically undesirable as they are much more rigid than silicone-based resins.

Adhesion Preferably the binder resin used provides a high level of adhesion with the glass aggregate to inhibit movement of the glass fragments when bound in the resin. It will be appreciated that the level of adhesion may be promoted by treating the glass with various agents. For example, the glass may be washed in glacial acetic acid to encourage resin adhesion.

Glass Aggregate It will be appreciated that the glass aggregate may include fragments in a range of sizes or combinations of sizes. Such variation in fragment size may provide consequential variations in the aggregate properties. For example, a larger size may provide increased rigidity and/or alter the light transmissibility. A larger size fragment may increase the separation between bound fragments and thus offer a matrix with a higher degree of porosity.

As used herein, the 'size' of a fragment refers to the longest cross-sectional dimension of the fragment.

Preferably the aggregate includes fragments within the size range of 5-15mm which 20 has been found to be particularly useful in providing an impermeable matrix with sufficient flexibility for various applications.

In a further preferred embodiment said fragments are within the size range of 8-12mm.

In an alternative embodiment the construction material may be substantially water 7 permeable, the aggregate fragment size being between 15 - 30mm though preferably 20mm.

In one embodiment a second aggregate including small glass fragments of less than 1 mm may be mixed with the resin before mixing with the larger fragment aggregate. 5 The inclusion of fine glass fragments ('frit') to the resin may provide an increased light scattering effect.

Preferably the glass fragments are provided from 'waste' glass. As will be appreciated by one skilled in that art, large quantities of 'waste' glass may be sourced from recycled household waste or container glass. The glass may preferably be of the 10 soda-lime variety though any silica glass may be suitable.

Aggregate Preparation Preferably the aggregate may be formed by passing waste glass into a crusher and then passed through a sizing screen. Preferably any particles too large to pass to the screen are re-processed by the crusher.

In a further embodiment the waste glass may be passed through a 'tumbler' to smooth the fragments.

Preferably the waste glass is first separated by colour and optionally washed to remove any labelling, detritus or other non-glass material.

Aggregate to Resin ratio It will be appreciated that the ratio (by volume) of aggregate to resin may be varied depending on the application and desired characteristics of the material. For example, a higher ratio (more glass) may provide a material with a relatively higher porosity.

Thus, according to one embodiment of the present invention there is provided a 8 substantially water impermeable glass composite matrix formed from a glass aggregate bound in a light-transmitting binder resin of a ratio of glass to resin of approximately 1:1 by volume. It will be appreciated that other ratios may provide sufficient impermeability depending on the resin viscosity, hardening properties and 5 glass fragment size.

In an alternative embodiment there is provided a substantially water permeable glass composite matrix formed from a glass aggregate bound in a light-transmitting binder resin of a ratio of glass to resin by volume of approximately 5:1. It will be appreciated that other ratios may provide sufficient permeability depending on the resin viscosity, 10 hardening properties, and/or glass fragment size, though large ratios (approximately greater than 10:1 for typical silicon resins) have been found to be too weak for most applications.

In one embodiment the composite matrix may be aerated to introduce air pockets. It will be appreciated that carbon dioxide, oxygen or any other suitable gas may be use 15 in the aeration process. An aerated matrix may provide a unique visual effect and/or provide a certain degree of water buoyancy.

Preferably the ratio of glass aggregate to resin is substantially between 1:1 and 5:1 by volume.

Building Element According to another aspect of the present invention there is provided a building element constructed from the construction material as aforementioned.

According to a further aspect there is provided a method of constructing a building element as aforementioned characterised by the steps of: - mixing said aggregate with said binder resin to form a composite matrix, 9 - laying said matrix over a substrate, said matrix curing to provide said building element.

In a further embodiment there is provided a method of constructing a building element as aforementioned characterised by the further step of: - providing a 'form' to constrain the matrix therein, the form containing said substrate.

The 'form' may include a frame, boxing, edging, mould or the like.

In a yet further embodiment there is provided a method of constructing a building element as aforementioned characterised by including the step of: - applying a separation layer on said substrate to inhibit adhesion of the matrix thereto.

It will be appreciated that the separation layer may include any one, or combination of: a membrane of plastic or polythene, a gel-type release agent such as a water or hydrocarbon based grease or emulsion, a release powder such as talc or sand, glass 15 frit, a surfactant foam.

Lighting According to another aspect of the present invention there is provided a lighting system including a building element as aforementioned, said lighting system including at least one light source positioned on a first side of the building element to transmit 20 light therethrough.

Preferably said building element is paving.

In a further embodiment the or each light source may be provided in recesses provided on the first side of the paving to emit light through the paving to a substantially opposing second side.

Preferably said paving is movable to provide access to the or each light source.

In one embodiment a said light source may be powered by one or more photoelectric cells. The use of photoelectric cells (i.e. solar panels) to power the light permits charging of the light during daylight hours for subsequent discharge at night. Photo-diode/resistor switches may be provided to turn the light on when light levels received by the photo-diode/resistor are below a predetermined level. The use of solar panels may alleviate drain from conventional electricity sources and may minimise wiring requirements.

Brief Description of Drawings Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings which are not to scale and in which: Figure 1a shows a plan view of a construction material according to a first aspect of the present invention; Figure 1b shows a plan view of an alternative embodiment of the construction material; Figure 1c shows a plan view of a further alternative embodiment; Figures 2a-b respectively show side views of the construction material of figure 1 b before and after smoothing an upper surface thereof; Figure 3 Shows a side section view of a lighting system according to another aspect of the present invention.

Best Modes for Carrying out the Invention 11 Referring to figures 1-3 there is provided a composite matrix (1) formed from an aggregate of glass fragments (2) bound in a light-transmitting binder resin (3) such as a room temperature vulcanizing silicone or polysiloxane though is preferably translucent polydimethylsiloxane.

The matrix (1) may be poured into a mould or onto a substrate before curing to produce any shaped building element. For example, paving slabs in a wide range of shapes and colours, for laying in lawns, paths, planter boxes or the like. In some applications the matrix (1) may be shaped to place around trees and shrubs or other features.

The cured matrix (1) provides a solid material that due to its flexibility can be used for high impact building elements such as paving, flooring and the like.

It will be appreciated that the matrix (1) may be formed 'on-site' or pre-cast depending on the particular application.

The translucent resin (3) and glass fragments (2) permit light to pass through the 15 matrix (1) which thus allows for lighting systems such as the under-lit paving system (5) shown in figure 3.

Figure 1 shows building elements in the form of bricks (4a-c) constructed from a composite matrix (1) according to a first aspect. The glass fragments (2) are embedded in the translucent binder resin (3) to provide rigidity, strength and aesthetic 20 qualities.

The brick (4a) of figure 1a contains a relatively higher ratio of glass (2) to resin (3) than the bricks (4b, c) respectively shown in figures 1b and 1c, thus providing a brick (4a) with a relatively high level of rigidity and strength and a different visual pattern. It will be appreciated that various different coloured glass fragments (2) may also be 25 used to vary the visual effect. 12 The fragments (2) are preferably provided from recycled 'waste' glass. The glass fragments (2) may be prepared by crushing bottles, container glass or the like.

Typical waste glass may also contain detritus, paper labelling or other foreign objects which may not adhere to the resin effectively or could create an undesirable visual 5 effect and thus may be removed from the glass aggregate.

In some applications the glass fragments (2) may be passed through a 'tumbler' to smooth the fragments (2) before mixing with the binder resin (3).

The brick (4b) shows a smaller ratio of glass (2) to resin (3) than brick (4a) to provide a relatively more flexible brick (4b) that may be used in applications which require 10 more resilience or flexibility. A more flexible material may also permit easier application of pre-cast bricks (4) into confined boundaries, which a relatively rigid brick (4) would not be able to flex into and would thus require re-sizing or modification Figure 1 c shows a brick (4c) with a similar ratio of glass to that of figure 1 b and includes a second aggregate of glass fragments (6) or 'frit' which are preferably <1mm 15 in size. The 'frit' (6) is added to the binder resin (3) before mixing with the larger glass fragments (2) and provides an increased light scattering effect.

It will be appreciated that direct light-transmissibility may not be desirable in some applications as the intensity of the light transmitted may be concentrated opposite the light source and thus provide an 'uneven' light distribution. Thus, to ensure even 20 distribution of light, complex placements of light sources may be required. Therefore it may advantageous to provide a building element (4c) with a high light-scattering effect to diffuse light transmitted therethrough.

The glass fragments (2) shown in figures 1b, 1c are also smaller than the fragments (2) shown in figure 1 a to provide more flexibility and a different visual effect. The glass 25 fragments (2) may be sized by passing through one or more sizing screens and any 13 fragments too large may be crushed again or, if too small, rejected.

It will be appreciated that the ratio of glass (2) to resin (3) may be varied depending on the application and desired characteristics of the material. For example, a higher ratio (more glass (2)) may provide a material with a relatively higher porosity.

As shown in Figure 2a, portions of glass fragments (2') in the composite matrix (1) may protrude from the surface (7) when initially laid into a mould or 'form'. It will be appreciated that in some applications, e.g. paving, it may be advantageous to provide a 'rough' surface to the matrix (1) to improve grip. The surface (7) of the matrix (1) may be levelled with a trowel moistened with soapy water or with a solvent such as 10 mineral turpentine and the matrix (1) left to cure. Thus, the level of irregularity of the surface (7) may be adjusted by the level of smoothing. Alternatively, in the embodiment shown in figure 2b, the surface (7) may be sanded to smooth the protruding glass fragments (2a) to create a smooth regular surface (7').

Figure 3 shows a paving and lighting system (5) including paving (8) constructed from 15 the composite matrix (1) overlaying lights (9) provided in recesses (10) in a concrete form (11). The lights (9) may be battery or mains powered, though for economy they are preferably powered by solar panels (not shown). The solar panels may be either directly attached to the lights or provided remote and the power wired to the lights (9).

The paving (8) constructed from the composite matrix (1) is flexible and thus the lights 20 (9) may be easily accessed by lifting the paving (8) from the form (11). Recesses (12) (with removable coverings (13)) may be provided to insert hooks under the paving (8) to assist lifting.

It will be appreciated that the paving (8) may be provided as a continuous length as shown in figure 3 or as a plurality of distinct portions. The only constraint on the shape 25 or size of any building element (4) is the shape and size of the mould or 'form' into 14 which it is laid.

To make the paving (3) shown in figure 3 the composite matrix (1) is formed by mixing the glass fragments (2) with the binder resin (3) and laying the flowable matrix over a transparent membrane (not shown) on the form (11) and leaving to cure. The membrane is provided to prevent the matrix (1) from adhering to the form (11) though it will be appreciated that some applications may require adherence of the matrix (1).

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

Claims (37)

CLAIMS:

1. A construction material including a composite matrix formed from a light-transmitting aggregate bound in a light-transmitting binder resin wherein said binder resin is flexible once cured such that the composite matrix is substantially flexible.

2. The material as claimed in claim 1 wherein said aggregate includes glass fragments.

3. The material as claimed in claim 1 or claim 2 wherein the refractive index of the aggregate and the binder resin are substantially the same.

4. The material as claimed in any one of the previous claims wherein the binder resin is substantially translucent.

5. The material as claimed in any one of the previous claims wherein the binder resin is substantially transparent.

6. The material as claimed in claim 4 or claim 5 wherein the binder resin is a room temperature vulcanizing silicone

7. The material as claimed in claim 4 or claim 5 wherein the binder resin is a polysiloxane.

8. The material as claimed in claim 7 wherein the binder matrix is polydimethylsiloxane.

9. The material as claimed in claim 4 or claim 5 wherein the binder resin includes 16 1 5 JUN 2007 one or more of: flexible thermoplastic, natural or synthetic rubber elastomers, polyurethane or acrylic foam.

10. The material as claimed in any one of the previous claims wherein the binder resin is diluted by mixing with a diluent.

11. The material as claimed in any one of the previous claims wherein the resin is mixed with a bulking agent.

12. The material as claimed in any one of the previous claims wherein the aggregate includes fragments within the size range of 5-15mm.

13. The material as claimed in claim 12 wherein the fragments are within the size range of 8-12mm.

14. The material as claimed in any one of claims 1-11 wherein said composite matrix is substantially permeable to water.

15. The material as claimed in any one of claims 1-11 wherein the aggregate fragment size is between 15 - 30mm.

16. The material as claimed in claim 15 wherein the aggregate fragment size is approximately 20mm.

17. The material as claimed in any one of the previous claims wherein said composite matrix includes a second aggregate including fragments of less than 1 mm in size.

18. The material as claimed in any of the previous claims wherein a said aggregate includes waste glass fragments. 17

19. The material as claimed in claim 18 wherein the aggregate is formed by passing waste glass into a crusher and then passed through a sizing screen.

20. The material as claimed in claim 18 or claim 19 wherein the waste glass is passed through a 'tumbler' to smooth the glass fragments.

21. The material as claimed in any one of claims 18-20 wherein the waste glass is first separated by colour.

22. The material as claimed in any one of the previous claims wherein the ratio of aggregate to resin is substantially between 1:1 and 5:1 by volume.

23. A substantially water impermeable construction material including a glass composite matrix formed from a glass aggregate bound in a light-transmitting binder resin with a ratio of aggregate to resin of approximately 1:1 by volume.

24. A substantially water permeable construction material including a glass composite matrix formed from a glass aggregate bound in a light-transmitting binder resin with a ratio of glass to resin of approximately 5:1 by volume.

25. A building element constructed from the construction material as claimed in any one of claims 1-24.

26. The building element of claim 25 wherein said building element is paving.

27. A method of constructing a building element as claimed in claim 25 or claim 26 characterised by the steps of: - mixing said aggregate with said binder resin to form a composite matrix, 18 - laying said composite matrix over a substrate, said composite matrix curing to provide said building element.

28. The method as claimed in claim 27 further including the step of: - providing a 'form' to constrain the matrix therein, the 'form' containing said

29. The method as claimed in claim 28 wherein the 'form' includes one or more of a frame, boxing, edging or mould.

30. The method as claimed in claim 28 or claim 29 further including the step of: - applying a separation layer on said form to inhibit adhesion of the matrix to said form and/or substrate.

31. A lighting system including a building element as claimed in claim 25 or claim 26, said lighting system including at least one light source positioned on a first side of the building element to transmit light therethrough.

32. The lighting system of claim 31 when dependant on claim 26 wherein the or each light source is provided in recesses provided on said first side to emit light through the paving to a substantially opposing second side.

33. The lighting system of claim 32 wherein said paving is movable to provide access to the or each light source.

34. The lighting system as claimed in any one of claims 31-33 wherein a said light source may be powered by one or more photoelectric cells. substrate. 19

35. Paving substantially as hereinbefore described with reference to, and as shown in figure 3.

36. A composite matrix substantially as hereinbefore described with reference to, and as shown in the drawings.

37. A lighting system substantially as hereinbefore described with reference to, and as shown in figure 3. Michael Ian Olsen by his authorised agents JAMES & WELLS Intellectual Property Office of N.Z, 1 5 JUN 2007 8 E C E IV F