AU769470B2 - Unsealed or a sealed base, methods of producing the base and base compositions - Google Patents

Description

WO 00/49229 PCT/AU00/00092 1 UNSEALED OR A SEALED BASE, METHODS OF PRODUCING THE BASE AND BASE COMPOSITIONS Technical Field i The present invention relates to an unsealed or a sealed base for a road, pathway, pavement, floor or the like. The present invention also relates to methods of producing the base and base compositions. In particular, the present invention relates to an unsealed or a sealed base, a base composition or method of producing the base and base compositions comprising lignin or lignosulphonate containing materials.

Background Of The Invention Asphalt and/or bitumen/bituminous emulsion compositions are typically utilised in the formation of roads. The formation of the road or pathway comprises firstly the formation of a road or pathway base which is substantially based on soil and various other components. The road or pathway base may be graded and then sprinkled with water before the road or pathway base is compacted by suitable means such as road rollers and the like. The means for compaction such as road rollers act to compact or compress the particles of soil together so as to provide a base, which is usually but not always substantially flat, before the asphalt and/or bitumen/bituminous emulsion compositions are then applied to an upper surface of the road or pathway base.

The formation of an unsealed surface such as a road or a pathway comprises firstly the formation of a road or pathway base which is substantially based on soil and various other components. The road or pathway base may be graded and then sprinkled with water before the road or pathway base is compacted by suitable means such as road rollers and the like. The means for compaction such as road rollers act to compact or compress the particles of soil together so as to provide a base, which is usually but not always substantially flat, to form an unsealed surface of the road or pathway base.

The use of various agents such as for use as binders and/or dispersants in the base act to strengthen the bonding of particles of soil in the road or pathway base composition.

The increased resistance in wear and tear of a road is to some extent dependent upon the compaction and bonding of the soil particles in the base.

However, based on the inventor's observations in practice, the compositions for road or pathway bases do not seem to be sufficient in bonding or compacting the particles of soil of the base composition. In the case of an unsealed road base, the resulting upper surface of the unsealed road base subsequently tends to break down more readily thereby resulting in the roads and paths having a tendency to form more potholes and cracks especially on those roads with high traffic loads. In the case of a sealed road base, the resulting asphalt and/or bitumen/bituminous emulsion compositions which are applied to the upper surface of the road base subsequently tend to break down more readily thereby Substitute Sheet (Rule 26) RO/AU resulting in the roads and paths having a tendency to form more potholes and cracks especially on those sealed roads with high traffic loads.

The increased tendency for sealed and unsealed roads to break down and form cracks, potholes, etc results in decreased life of new roads which consequently leads to eventual problems with repairing and maintaining roads especially in roads with heavy traffic usage.

The present invention seeks to ameliorate the problems of the known base compositions and compositions for roads, pathways, pavements and the like by providing, at least, an unsealed or sealed base, an alternative composition for roads and bases and a method of stabilising such road bases for sealed and unsealed roads.

Summary of the Invention Disclosed herein is a method of producing a base comprising the following steps: mixing at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and (iii) soil; to form a base composition, and compacting the base composition to form a base.

Base as used throughout the specification and claims includes within its scope one or more layers selected from the group consisting of the base layer, the sub base layer the subgrade layer and other formation layers. Thus for example the base of a road may have 2" three or more layers the base layer, the sub base layer the subgrade layer and other 25 formation layers and one or more of these layers may be a base formed in accordance with the process of the invention. Each layer may be independently formed with different relative amounts and with different types of materials. At least the base layer is prepared according to the method of the invention however, this will be dependent on the particular requirements. For example, the sub base may be the only layer formed in accordance 30 with the method of the invention. Usually the base is flexible under load and is resilient.

"Advantages of a base of the invention are that it has improved strength, flexibility and resilience as compared to bases not made in accordance with the method of the invention.

In the method step may further comprise the step of mixing: (iv) water; [R:\libz]41681.doc:SAK with (ii) and (iii).

In the method of the invention step may further comprise the step of mixing: (iv) water in an amount where the base composition is substantially at or about an optimum moisture content that enables substantially maximum compaction of the base composition.

In the method step may further comprise the step of mixing: a filler: with (ii) and (iii) or with (iii) and (iv).

In one particular form of the method step comprises: mixing in an amount of O.lwt%-15wt% at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) in an amount of O.lwt%-15wt% at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and 70wt%-99.8wt% soil.

In another particular form of the method step comprises: mixing in an amount of O.lwt%-15wt% at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) in an amount of 0.lwt%-15wt% at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; (iii) 70wt%-99.8wt% soil; and (iv) Owt%-25wt% water.

Typically the amount of water is such that the base composition is at or about the optimum moisture content for maximum compaction.

25 In a further particular method step comprises: mixing in an amount of O.lwt%-15wt% at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) in an amount of O.lwt%-15wt% at least one additive selected from the group 30 consisting of cement, lime, flyash, calcium sulphate and slag; (iii) 70wt%-99.7wt% soil; and O.lwt%-15wt% of a filler.

In another particular method step comprises: mixing [R:\libz]41681.doc:SAK in an amount of 0.1wt%-15wt% at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) in an amount of 0. 1wt%-15wt% at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; (iii) 70wt%-99.7wt% soil; (iv) Owt%-25wt% water; and 0.lwt%-15wt% of a filler.

In another form of the method step comprises: mixing 0t in an amount of 0.1wt%-15wt% at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) in an amount of 0.1wt%-15wt% at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; (iii) 70wt%-99.7wt% soil; (iv) Owt%-25wt% of water; and 0.lwt%-15wt% of a filler.

Advantageously in the method step comprises: (iv) 1-15wt% water.

The method may further comprise: sealing the base with a sealant.

Also disclosed herein is a base composition comprising: at least one binder selected from the group consisting of lignin and lignosulphonate; and (ii) at least one additive selected from the group consisting of cement, lime, 25 flyash, calcium sulphate and slag.

The base composition may further comprise at least one component selected from the group consisting of (iii) soil; a filler; and (iv) water.

Also disclosed is a method of producing a base composition comprising the following steps: mixing at least one binder selected from the group consisting of lignin and lignosulphonate; and (ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and (iii) soil; [R:\libz]41681 .doc:SAK to form the base composition.

Also disclosed is a method of producing a base composition comprising the following steps: mixing at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and (iii) soil; water; to form the base composition.

The method may comprise the step of mixing: (iv) water in an amount where the base composition is substantially at or about an optimum moisture content that enables substantially maximum compaction of the base composition.

The step of mixing may further comprise the step of mixing: a filler; with (ii) and (iii), and where appropriate (iv).

Also disclosed is a method of producing a base composition comprising the following steps: mixing at least one binder selected from the group consisting of lignin and lignosulphonate; (ii) at least one additive selected from the group consisting of cement, lime, 25 flyash, calcium sulphate and slag; and (iv) a filler; to form the base composition.

In the method the step of mixing may further comprise the step of mixing: (iii) soil; with (ii) and In the method the step of mixing may further comprise the step of mixing: (iii) soil; (iv) water; with (ii) and In the method the step of mixing may further comprise the step of mixing: [R:\libz]41681.doc:SAK (iii) soil having more than 10%-25% sieve analysis at a sizing of-0.075mm; (iv) water in an amount where the base composition is substantially at or about an optimum moisture content that enables substantially maximum compaction of the base composition, with (ii) and The invention provides A base composition produced by a method of the invention; (II) A sealed base produced by a method of the invention; (III) A base produced by a method of the invention.

Also disclosed herein is a base composition comprising: i) at least one binder selected from the group consisting of lignin and lignosulphonate; and ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag.

Also disclosed is a base composition comprising: i) at least one binder selected from the group consisting of lignin and lignosulphonate; ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and iii) soil.

Also disclosed is a base composition comprising: i) at least one binder selected from the group consisting of lignin and lignosulphonate; ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and 25 iii) soil; and (iv) water in an amount up to a point where the composition is substantially at or about an optimum moisture content that enables substantially maximum compaction of the base composition.

Also disclosed herein is a base composition comprising: i) at least one binder selected from the group consisting of lignin and lignosulphonate; ii) at least one additive selected from the group consisting of cement, lime, flyash, calcium sulphate and slag; and iii) soil; and [R:\libz]41681.doc:SAK 1 WO 00/49229 PCT/AUOO/00092 7 iv) water in an amount that enables compaction of the base composition so as to torm a base.

Typically the slag comprises blast furnace slag.

Typically, the amount of water is added to components i) to iii) either before, at the same time or after the mixture of components i) to iii). The water is still typically added so as to not exceed the at or about optimum moisture content of the base composition although if more water is added suitable materials such as cement and/or lime and/or tlvash and/or calcium sulphate and/or blast furnace slag may be added to absorb excess water so as to provide the at or about optimum moisture content. Further, the base composition may be dried or evaporated by suitable means so to provide the at or about optimum moisture content of the base composition.

The optimum moisture content will vary and be dependent on the types and the relative amounts of the components in the base composition as described for the embodiment of the present invention. The optimum moisture content will typically decrease when more of component i) is present since lignin or lignosulphonates act as dispersants whilst the optimum moisture content will typically increase when more of component ii) is present since the component ii) acts as an absorbent material. The optimum moisture content will further depend on the modifiers added to the composition of the third embodiment of the present invention.

Throughout this specification, the term "optimum moisture" for the base composition is defined as the moisture content whereby maximum compaction of the composition occurs. The compositions of the invention may be such as to be about the optimum moisture content for maximum compaction of the composition of the invention (this refers to compositions of the invention that include soil) e.g. in the range optimum moisture content 5wt%, optimum moisture content 4wt%, optimum moisture content 3wt%. optimum moisture content 2wt%, or optimum moisture content lwt%.

Water is added as required to bring such compositions to the optimum moisture content or about the optimum moisture content.

Lignosulphonate PLUS Additive PLUS Fillers Always used- Usually at least two of Not always used one or more of the Cement, Quick Lime one or more of types listed herein Hydrated Lime, Slag Bentonite usually at least two or three Fly ash, Fire Clay Silt Typically. compaction tests are used to determine the optimum moisture content of the base composition of the present invention comprising a particular soil as component iii> which has to be compacted optionally together with other components in order to attain the maximum dry density. Still typically, the laboratory compactive effort is Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AUOO/00092 8 standardised upon the premise that it duplicates field compaction and thus the material is compacted at various moisture contents using a fresh portion of base composition for each moisture content applied. As the moisture content increases, dry density increases to a certain maximum but then decreases. The plotting of dry densities against moisture contents provides a moisture content density curve corresponding to a given compaction cflort for the base composition. This obviously shows that for each base composition there is a given maximum compaction that can be achieved for each moisture content.

However. other compaction tests used in the field may also be utilised to provide an approximate moisture content of the base composition. For example. a hand test may be used to provide an approximate optimum moisture content.

The range of weight ratios of soil or soil having an optimum moisture content to the total weight ratio of other components in the mixture in those forms of the invention that concern soil are shown below in Table C by reading the "'Third Component" as the \\eight ratio summation of the components other than soil.

The sealed surface is typically a sealing layer which seals the base of the invention to which it is overlayed. adhered or bonded, such as sealed with paving blocks, a concrete surtace. a road, pathway, pavement or floor having sealed surface such as concrete, bitumen and/or asphalt, or a road, pathway, pavement, floor and the like sealed with another suitable sealing agent. The sealed surface is further typically a road, pathway or pavement and still further typically the sealed surface is a road. The road is typically made from a composition comprising asphalt and/or bitumen/bituminous emulsion compositions which is designed to carry high volumes of traffic. Still typically, crushed stone and gravel are added to the bitumen/bituminous emulsion composition designed to carry high volumes of traffic.The sealed surface may also be a sealed railway track bed below the ballast. The base of the invention may be effectively sealed when it is a base helow concrete, a base below concrete foundations, a base below paving blocks or a shock absorbent base below a building structure, for example.

In a particular form of the invention the base composition is in a powdered form which may be then blended with soil in an appropriate ratio and a suitable amount of water added, if necessary, to bring the moisture content of the mix at or about the optimumn moisture content for optimum compaction. In an alternative form, a suitable amount of water may be added to form a paste or slurry or moist mixture so as to provide an amount of moisture for the base composition which may or may not be at optimum but is an amount whereby the composition is suitable for compaction as a road base or a hase for some other purpose such as a footpath, pathway, parking area, etc. Usually the amount of water added is such so as to provide optimum moisture. for the base composition. Throughout this specification, the term "optimum moisture" for the base composition is defined as the moisture content whereby maximum compaction of the Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AUOO/00092 9 composition can be effected by standard compaction techniques. Yet still typically, the amount of water added to the base composition is I to 20 weight The water may be added either before, at the same time or after mixing components a) and ii) and optionally iii) above. The amount of water added to the base composition to provide optimum moisture will vary dependent upon the amounts of components ii) and iii) above and also the type of soils used for component iii) above. The component i) above will typically act as a dispersant thereby generally reducing the amount of water required for the base composition whilst the component ii) above will typically act as an absorbent material for water present in the base composition.

to In one form of the invention the base composition is used as an unsealed surface having components i) and ii) above with iii) soil where component ii) is cement and/or lime and/or flyash. The unsealed surface is typically a road, pathway, floor, railroad track bed below the ballasts, or pavement or the like and still further typically the unsealed surface is a road.

The lignin or lignosulphonate is typically a salt of lignosulphonic acid including alkali metal salts thereof, alkaline earth metal salts thereof. transition metal salts thereof, ammonium salts thereof, ammonium polymerised salts thereof, chromium salts thereof, and other water soluble salts thereof.

The alkali metal salts of lignosulphonic acid typically comprise lithium lignosulphonate, sodium lignosulphonate, potassium lignosulphonate.

The alkaline earth metal salts of lignosulphonic acid typically comprise calcium lignosulphonate. magnesium lignosulphonate. barium lignosulphonate.

The transition metal salts of lignosulphonic acid typically comprise ferrous lignosulphonate.

The ammonium salt comprises ammonium lignosulphonate and a polymerised salt of lignosulphonic acid typically a polymerised alkylene napthalene lignosulphonic acids and the ammonium salt thereof.

The lignin or lignosulphonate in the present invention may be either used individually as a single component or as a mixture of more than one component. The lignin or lignosulphonate most typically used is ammonium lignosulphonate, calcium lignosulphonate or sodium lignosulphonate which may be used either individually or as a mixture. The selection of the lignin or lignosulphonate is typically dependent upon the soil which is used in the said base composition.

The lignin or lignosulphonate may also be admixed with alkali metal salts, alkaline earth metal salts and ammonium polymerised salts of sulphonic acid to form a mixture of the lignin or lignosulphonates together with the aforesaid sulphonates.

The cement is typically selected from hydraulic cements or non-hydraulic cements.

The hydraulic cements include cements which are hydraulically active and may include Substitute Sheet (Rule 26YRO/AU "1 WO 00/49229 PCT/AU00/00092 materials such as hydraulic cement, slag and blends of hydraulic cement thereof. The term "hydraulic cements" refers to any inorganic cement which hardens or sets due to hydration. The term "hydraulically active" refers to properties of a cementitous material that allows the material to set in a manner like hydraulic cement. either with or without additional activation. Hydraulically active cementitous materials may also contain minor amounts of fillers or extenders such as bentonite. gilsonite. and cementitous materials used either without any appreciable sand or aggregate material or admixed with a granular filling material such as sand. ground limestone and the like. Strength enhancers such as silica powder or silica flour may be employed as well.

1o Hydraulic cements typically comprise Portland cements, aluminous cements, pozzalan cements, fly ash cements, and the like. Thus. for example, any of the oilwell type cements of the class and as listed in the API Spec 10, (1st Edition), are suitable and fall within the definition of hydraulic cements.

The typical cements which are utilised in the base composition are hydraulic cements with Portland Cement being the most preferred cement. The Portland Cement may be Class G Portland Cement. ordinary Portland Cement and rapid hardening Portland Cement. The Portland cement may also be admixed with other cements such as aluminous cements, pozzalan cements, fly ash cements and the like.

Typically, Portland cement is admixed with high alumina cement, anhydrous calcium sulphate and a lithium salt which is used as an accelerator for setting of-the cement. A strong base may also be added to the lithium salt in order to assist in the acceleration of the setting of the cement. Typically, the anhydrous calcium sulphate is in the form of an alpha-anhydrite calcium sulphate, beta-anhydrite calcium sulphate or a mixture thereof. Typically, the strong base is sodium hydroxide, potassium hydroxide or sodium aluminate. Typically the lithium salt is lithium carbonate, lithium hydroxide.

The calcium sulfate may also be present in the form of a calcium sulphate di hydrate. calcium sulphate hemi hydrate and as a calcium sulphate hemi hydrate of gypsum. The calcium sulfate may also be used by itself in the base composition of the lirst and second embodiments of the present invention as a component.

The lime typically used in the present invention is selected from the group of lquicklime. hydrated or slaked lime, high calcium lime. limestone, gypsum, non magnesian and magnesian limes, etc. The lime used in the base composition is most typically hydrated or slaked lime. Hydrated lime is typically made by the reaction of quicklime (calcium oxide) with water to form slaked or hydrated lime. The hydrated lime is typically selected from magnesian lime, high calcium lime and non magnesian lime.

Sodium metasilicate may also be added to the composition instead of or additionally with lime.

Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AUOO/00092 11 The lignosulphonates typically act as retarders. However a set retarder may also be added to the composition to prevent the setting of the slurry. The characteristics of these set retarders are diverse and important. An effective amount of set retarder allows the storage of the slurries with minimal changes in the characteristics of both the stored and activated slurry. It is equally important that this effect is reversible after adding an effective amount or low concentration of activator in the slurry.

Typical set retarders comprise glucoheptanoates such as sodium glucoheptanoate; calcium glucoheptanoate and magnesium glucoheptanoate: lignosulphonates such as sodium lignosulphonate. calcium sodium lignosulphonates: low molecular weight io hydroxy polycarboxylic acid and salts thereof including sodium, potassium and lithium salts thereof: alkaline hexametaphosphate, calcium chloride and/or a condensation product of mononapthalene sulphonic acid and formaldehyde: lithium, sodium and potassium salts of citric acid and tartaric acid.

The lignosulphonates typically act as a dispersant. However a dispersant may also is he added to the composition and typical dispersants may be selected from the group of sodium di hydrogen phosphate buffer, ferrous sulphate, tannic acid or a mixture thereof.

A surfactant may also be added to the composition and typical surfactants may be selected from the group of anionic, cationic or non-ionic surfactants comprising polyethoxylated alcohols especially polyethoxylated alkylphenol or polyethoxylated methanol, ethanol and propanol surfactants.

The flyash typically used in the present invention comprises flyash alone or in combination with blast furnace slag. The blast furnace slag may also be used as another optional component with the base composition of the first or second embodiment of the present invention.

The soils of the present invention include crushed rock based soils, soft soils, sand based soils. gravel based soils, shale based soils, soils of volcanic origin, peat based soils, crushed rock, soil containing crushed rock, other stone based soils, shell based soils, coral based soils, volcanic soils, organic based soils, other particulate based soils, clay based. silt based soils or a mixture of any one or more of the aforesaid soils. The soils are still typically swamp clay soils, silt, volcanic silt or puggy black soil or any mixture thereof. The term soil also encompasses within its scope, mining waste materials, and mineral process plant waste materials including colliery waste materials and refuse. The soils may also contain additional particulate material such as required for use in sealed surtaces such as typically roads, pathways, pavements or the like. Typically, any soil that has particles which achieve more than 10% sieve analysis at a sizing of -0.075mm and liurther typically at more than 20% sieve analysis at a sizing of -0.075mm is suitable for lhe present invention. However. soil with particles less than 10% sieve analysis may be Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 12 used by blending soil with other fillers, such as fire clay, volcanic silts. bentonite, and the like.

The typical percentage ratio of component i) lignin or lignosulphonate in respect of the combination of components i) and ii) is: typically 1 to 99 percent by weight, further typically 25 to 95 percent by weight.

still further typically 30 to 95 percent by weight, still further typically 35 to 95 percent by weight still further typically 40 to 95 percent by weight.

o1 still further typically 45 to 95 percent by weight.

still further typically 50 to 95 percent by weight.

The typical percentage ranges of component ii) cement and/or hydrated lime and/or calcium sulphate and/or blast furnace slag. and/or flyash in respect of components i) and ii) is typically I to 99 percent by weight. further typically 25 to 95 percent by weight. still lurther typically 30 to 95 percent by weight, still further typically 35 to 95 percent by weight. still further typically 40 to 95 percent by weight, still further typically 45 to percent by weight. still further typically 50 to 95 percent by weight, The typical range for the cement in component ii) is typically 0 to 100 percent by weight. further typically 0 to 90 percent by weight, still further typically 0 to 80 percent by weight. still further typically 0 to 70 percent by weight, still further typically 0 to percent by weight, still further typically 0 to 50 percent by weight, still further typically 0 to 40 percent by weight. still further typically 0 to 35 percent by weight.

The preferred range for the lime in component ii) is typically 0 to 100 percent by weight. further typically 0 to 90 percent by weight, still further typically 0 to 80 percent by weight, still further typically 0 to 70 percent by weight, still further typically 0 to percent by weight, still further typically 0 to 50 percent by weight, still further typically 0 to 40 percent by weight. still further typically 0 to 35 percent by weight.

The preferred range for the flyash in component ii) is typically 0 to 100 percent by weight. further typically 0 to 90 percent by weight, still further typically 0 to 80 percent by weight, still further typically 0 to 70 percent by weight. still further typically 0 to 60 percent by weight, still further typically 0 to percent by weight, still further typically 0 to 40 percent by weight, still further typically 0 to 35 percent by weight: subject to the proviso that at least one of cement, lime or flyash is present in component ii) in an amount of at least 1 weight percent.

The typical percentage ranges of component iii) soil in respect of the total composition is typically 75 to 99.7 percent by weight, still further typically 80 to 95.0.

percent by weight. and still further typically 90 to 95.0 percent by weight.

Substitute Sheet (Rule 26) RO/AU The typical percentage range of component iv) water is typically 0 to 25 percent by weight, typically 1 to 15 percent by weight, further typically 1 to 10 percent by weight, and still further typically 1 to 5 percent by weight and is still typically dependent upon soil conditions and the soil. Typically water is added to the soil in an amount of 3- 18wt%, 5-15wt%, 8-12wt% or 10-12wt%. The optimum typical percentage range of water in the base composition is the point of achieving optimum moisture in soil as previously defined.

Further, the soil may comprise a composition of or include residual cement, residual concrete bitumen or asphalt, or residual broken paving blocks.

In a first aspect of the invention there is provided a base composition for use in preparing a base for a road, pavement or the like, comprising: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; from 20 wt% 50 wt% of an additive selected from the group consisting of lime and hydrated lime; and from 20 wt% 60 wt% of cement.

with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

In another aspect of the invention there is provided a base composition for use in preparing a base for a road, pavement or the like, comprising: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; and 25 from 40 wt% 80 wt% of a combination of cement and an additive selected from the group consisting of lime and hydrated lime, wherein the cement in said combination is present in an amount up to 90 wt% of the combination, with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

30 In yet another aspect of the invention there is provided a base composition for use as a base for a road, pavement or the like, comprising: from 0.8 wt% to 2 wt% of a compound selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; [R:\libz]41681.doc:SAK

S(

14 from 0.25 wt% to 2.5 wt% of an additive selected from the group consisting of lime and hydrated lime; from 0.5% wt to 5.0% wt% of cement; and from 75 wt% to 99.7 wt% soil, with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

In still another aspect of the invention there is provided a base composition for use as a base for a road, pavement or the like, comprising: a binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; a combination of cement and an additive selected from the group consisting of lime and hydrated lime, wherein the cement in said combination is present in an amount of up to 90 wt% of the combination; and soil, wherein the binder is present in an amount between 20 and 60 wt% of the total amount of the compound and the combination and the soil is present in amount between 75% and 99.7 wt% of the total amount of the composition, with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and length.

In a further aspect of the invention there is provided a process for producing a base G* a for a road, pavement or the like, comprising mixing: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium 25 lignosulphonate and mixtures thereof; from 20 wt% to 50 wt% of an additive selected from the group consisting of lime and hydrated lime; and from 20 wt% to 60 wt% of cement.

with the proviso that the process does not comprise adding more than 0.2 wt% mineral or S 30 vegetable fibres of between 5 and 20mm length.

In yet a further aspect of the invention there is provided a process for producing a base for a road, pavement or the like, comprising mixing: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; and [R:\libz]41681.doc:SAK "I 1 S from 40 wt% 80 wt% of a combination of cement and an additive selected from the group consisting of lime and hydrated lime, wherein the cement in said combination is present in an amount up to 90 wt% of the combination, with the proviso that the process does not comprise adding more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

In still a further aspect of the invention there is provided a process for producing a base for a road, pavement or the like, comprising mixing a composition according to the invention with soil.

The invention also encompasses a base composition when made by a process of the invention.

Accordingly, in another embodiment, the present invention provides a composition comprising: i) at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; ii) at least one additive selected from the group consisting of cement, hydrated lime, lime, flyash, calcium sulphate and blast furnace slag; iii) soil; and d) a sealant.

Typically, the sealant is selected from asphalt, bitumen, bituminous emulsions or a combination thereof, concrete, cement, or other sealing compounds or admixtures. The composition is still typically asphalt and/or bitumen or bituminous emulsion o e *compositions. The asphalt and/or bitumen or bituminous emulsion compositions provide o o a strong bonding strength with the components ii) and iii) when admixed such that the durability of the sealed surface is increased.

25 Accordingly in a further embodiment, the present invention also provides a sealed surface composition comprising: i) at least one binder from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; ii) at least one additive selected from the group consisting of cement, hydrated lime, lime, flyash, calcium sulphate and blast furnace slag; Siii) soil; iv) water in an amount up to a point where the base composition is substantially at or about an optimum moisture content that results in maximum compaction of the base composition; and [R:\libz]41681 .doc:SAK

V

e) one or more materials selected from the group consisting of asphalt, bitumen and bituminous emulsion compositions.

The sealed surface is further typically a road, pathway or pavement and still further typically the sealed surface is a road. The sealed surface is typically made from a composition comprising asphalt and/or bitumen/bituminous emulsion compositions which is designed to carry significant traffic.

The typical percentage ratio of component i) lignin or lignosulphonate in respect of the total composition is typically 0. 1 to 1 5 percent by weight. further typically 0.5 to percent by weight. and still further typically 0.75 to 5 percent by weight.

The typical percentage ratio of component i) lignin or lignosulphonate in respect of The typical percentage ranges of component ii) cement and/or hydrated lime and/or in respect of the total composition is typically 0 to 5 percent by weight, further 0.5 to 3 percent by weight.

The typical range for the cement in component ii) is typically 0 to 5 percent by weight, further typically 0.5 to 3 percent by weight.

The typical range for the lime in component ii) is typically 0 to 5 percent by weight, further typically 0.5 to 3 percent by weight.

subject to the proviso that at least one of cement, lime or flyash is present in component in an amount of at least 0. 1 weight percent.

The typical percentage ranges of component iii) soil in respect of the total e g.

composition is typically 70 to 99.7 percent by weight, still further typically 30 to 95 percent by weight.

still further typically 85 to 95 percent by weight, still further typically 90 to 95 percent by S 25 weight.

0 0.

The percentage range of component iv) water is typically 0 to 25 percent by weight, further typically 1 to 15 percent by weight, further typically I to 10 percent by weight, arid still further typically 1 to 5 percent by weight and is yet still typically dependent upon soil conditions. The optimum typical percentage range of water in the base composition is the point of achieving optimum moisture content in soil as previously defined.

The typical percentage range of component e) asphalt and/or bitumen/bituminous o emulsion composition is typically 5 to 95 percent by weight, further typically 10 to percent by weight, typically 15 to 80 percent by weight, typically 20 to 70 percent by [R:\libz]41681 .doc:SAK In Vl weight: further typically 25 to 60 percent by weight. still further typically 30 to 50 percent by weight, still further typically 35 to 40 percent by weight.

Also herein is disclosed a method producing a base of aI sealed surface comprising the following steps: a) treating the soil with a mixture of: i) lignin or lignosulphonate; and ii) cement and/or lime and/or flyash and/or calcium sulphate and/or blast furnace slag; iii) adding water in an amount up to a point where the base composition is lo substantially at or about an optimum moisture content that results in maximum compaction of the base composition.

b) compacting the resulting composition by suitable means to form a base.

Also disclosed is a method for producing a base comprising the following steps: a) treating the soil with a mixture of: i) lignin or lignosulphonate; and ii) cement and/or lime and/or flyash and/or calcium sulphate and/or blast furnace slag; compacting the resulting composition by suitable means to form base.

Also disclosed is a method for producing a base having an unsealed surface comprising the following steps: a) treating the soil with a mixture of: i) lignin or lignosulphonate; and cement and/or lime and/or flyash and/or calcium sulphate and/or blast furnace slag; and water in an amount up to a point where the base composition is substantially at or about S 25 an optimum moisture content; b) compacting the resulting composition to form a base having an unsealed surface.

In a typical embodiment, the method further comprises c) adding a sealant to the base composition to form a sealed surface. Typically c) comprises forming a sealing layer 30 of a sealant over the base. Thus a sealant may be spread over the base and hot rolled so as to form a sealing layer of sealant over the base.

Accordingly, in yet another aspect of the invention there is disclosed a process for ,o making a composition, a road, pathway or pavement comprising the steps of: treating soil with a composition according to the first aspect of the invention; compacting the composition to form a base having an unsealed surface; and [R:\libz]41681 .doc:SAK I adding a sealing layer of sealant comprising one or more materials selected from the group consisting of asphalt, bitumen and bituminous emulsion compositions over the base.

The invention also encompasses a composition or a road, pathway or pavement when made by the process of this aspect.

The sealed surface comprises or is typically paving blocks, a concrete surface, road, pathway, pavement, floor and the like. The sealed surface is further typically a road, pathway or pavement and still further typically the sealed surface is a road. The sealed surface is typically made from a composition comprising asphalt and bitumen which is designed to carry significant traffic.

Typically the step a) above may be carried out by adding either component i) lignin or olignosulphonate first, after or together with component ii) cement and /or lime and/or flyash with soil. However, the mixture of component i) lignin or lignosulphonate and component ii) cement and/or lime and/or flyash may also be added before the introduction with soil.

Usually components and (ii) or (ii) and are premixed in the required relative proportions to form a premix. The premix is then mixed in the desired proportion with the soil prior to adding water. Water is then added and mixed in as required, the water added usually in being an amount to achieve optimum compaction or to achieve about a *oo o* oo ooo* o o [R:\libz]41681 .doc:SAK WO 00/49229 PCT/AUOO/00092 16 optimum compaction (typically 5% of optimum compaction, more typically 5% of optimum compaction.

Typically. step b) is carried out after the treatment of soil with the mixture of component i) lignin or lignosulphonate: and ii) cement and /or lime and/or flyash. Typically, the step c) is carried out after steps a) and b) have been completed and is typically achieved by use of road rollers. However, the addition of water is usually made in situ after preparing a base composition of soil. component i) lignin or lignosulphonate and ii) cement and /or lime and/or flyash and/or calcium sulphate and/or blast furnace slag, and if required.

S1 Typically. the method also additionally comprises step d) which is the introduction of a sealant typically a bitumen/bituminous emulsion composition and/or asphalt which is provided as a layer over the top of the base and formed into a sealed surface by suitable means, so as to form a road. pavement, pathway, floor and the like. The introduction of said asphalt and/or bitumen/bituminous emulsion compositions firstly typically 1s comprises the addition of bitumen/bituminous emulsion composition before the addition of asphalt when both of these materials are used as a sealant.

TIypically the base composition is added in an amount in the range 20 100kg per cubic metre of soil (typically 20. 30. 40, 50, 60. 70. 80. 90 or 100kg per cubic metre). Where a depth of 100mm is required the base composition is typically added in an amount of 2 o2 12. typically 4 10 kg per square metre, for 150 mm 4 18. typically 6 15kg per square metre. and for 200 mm 6 24, typically 8 20 kg per square metre. In one form of the invention, steps a) and b) are carried out such that a slurry of components i) lignin or lignosulphonate: and ii). in water, are formed, subject to the condition that the amount of water added is to provide an optimum moisture content as previously defined.

Typically. step a) above may be also carried out by firstly adding a powdered form ol the mixture of cement and/or lime and/or flyash with water so as to provide optimum moisture content as previously defined. The lignin or lignosulphonate may also be added to the powdered mixture together with any desired additives such as dispersants, binders and the like.

Typically, the lignin or lignosulphonate may be a salt of lignosulphonic acid including alkali metal salts thereof, alkaline earth metal salts thereof, ammonium, ammonium polymerised, chromium, and other water soluble lignosulphonates either used individually or as a mixture. The lignosulphonate preferably used is ammonium, calcium or sodium lignosulphonate either individually or as a mixture.

The cement is typically selected from hydraulic cements or non-hydraulic cements.

The hydraulic cements include cements which are' hydraulically active and may include materials such as hydraulic cement, slag and blends of hydraulic cement thereof. The term "hydraulic cements" refers to any inorganic cement which hardens or sets due to Substitute Sheet (Rule 26)RO/AU WO 00/49229 PCT/AUOO/00092 17 hydration. The term "hydraulically active" refers to properties of a cementitous material that allows the material to set in a mamner like hydraulic cement. either with or without additional activation. Hydraulically active cementitous materials may also contain minor amounts of extenders such as bentonite, gilsonite. and cementitous materials used either without any appreciable sand or aggregate material or admixed with a granular filling material such as sand. ground limestone and the like. Strength enhancers such as silica powder or silica flour may be employed as well.

Hydraulic cements typically comprise Portland cements. aluminous cements, pozzalan cements, fly ash cements, and the like. Thus. for example, any of the oilwell type cements of the class and as listed in the API Spec 10, (1st Edition), are suitable and fall within the definition of hydraulic cements.

Hydraulic cements are most typically used in the method and Portland Cement is the preferred cement used in the method of producing a base for a sealed surface.

The lime typically used in the present invention is selected from the group of hydrated lime. lime etc.

The flyash typically used in the present invention comprises flyash. alone or in combination with blast furnace slag. The blast furnace slag may also be used as another optional component with the base composition of the first or second embodiment of the present invention.

The soils of the present invention are typically selected from the group of crushed rock based soils, sand based soils, gravel based soils, other stone or other particulate based soils, clay based. silt based soils or a mixture thereof. The soils are still typically swamp clay. silt. volcanic silt silt surrounding Auckland Harbour) and puggy black soil. The soils may also contain additional particulate material such as required for particulate roads. pathways, pavements or the like. Typically. any soil that has particles which achieve more than 10% sieve analysis at a sizing of -0.075mm and further typically at more than 15% or 20% is suitable for the present invention. A soil that achieves a sieve analysis in the range 10 100%, 10 90%, 10 80%. 10 70%. 10 10 50%. 15 100%, 15 90%. 15 80%. 15 70%, 15 60%, 15 50%, 15 40%. 15 30%. 10 25%. 12-25%, 12-20%. 15-25%, 15-20%. 15-23% at a sizing of- 0.075mm is particularly suitable. Where the sieve analysis of the soil falls outside these ranges it is desirable to blend additional particulate material (such as a filler e.g.

hentonite. fire clay. silt. other fines. etc) to the soil to bring it into one of these ranges.

Typically 15 25% fines at a sizing of -0.075mm is preferred.

The following Table A provides a typical blend proportion of component i) lignin or lignosulphonate and ii) Portland Cement and/or hydrated Lime and/or Flyash and/or Blast Furnace Slag and/or Calcium Sulphate when admixed together. Table A illustrates I'or entries numbered 1-24 the blend proportion a:b (parts by weight) where a is selected Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 18 fromn the group of a value presented in the column headed in Table A below at one of entries 1-24. and b is selected from the group of the values presented in the column headed adjacent the corresponding entry. The lignin or lignosulphonate proportion is shown under the column headed whilst the Portland Cement and/or hydrated lime and/or flyash and/or blast furnace slag and/or calcium sulphate proportion is shown under the column headed Table A Entry a b 1 10 0.5. 1.0. 1.25, 1.5, 1.75. 2.0, 2.25. 2.5, 2.75. 3.0, 3.25, 3.75, 4.0, 4.25. 4.5. 4.75. 5.0. 5.25. 5.5, 5.75. 6.25. 6.5. 6.75, 7.0, 7.25, 7.5. 7.75. 8.0. 8.25, 8.75. 9.0. 9.25. 9.5, 9.75. 10.0. 2 9.80 0.5. 1.0. 1.25, 1.5. 1.75. 2.0. 2.25. 2.5. 2.75. 3.0. 3.25, 3.75, 4.0. 4.25, 4.5, 4.75, 5.0. 5.25, 5.5, 5.75, 6.25, 6.5, 6.75, 7.0. 7.25. 7.5, 7.75. 8.0. 8.25, 8.75. 9.0. 9.25. 9.5. 9.75. 10.0. 39.75 0.5, 1.0. 1.25, 1.5. 1.75, 2.0. 2.25. 2.5, 2.75, 3.0, 3.25, 3.75. 4.0. 4.25. 4.5. 4.75. 5.0. 5.25. 5.5, 5.75, 6.25, 6.5. 6.75. 7.0. 7.25, 7.5. 7.75. 8.0. 8.25, 8.75. 9.0. 9.25. 9.5. 9.75. 10.0. 4 9.50 0.5. 1.0, 1.25, 1.5, 1.75. 2.0, 2.25. 2.5, 2.75, 3.0, 3.25, 3.75, 4.0, 4.25, 4.5. 4.75. 5.0. 5.25. 5.5. 5.75, 6.25. 6.5, 6.75, 7.0. 7.25. 7.5. 7.75, 8.0. 8.25. 8.75. 9.0. 9.25, 9.5. 9.75. 10.0. 9.25 0.5. 1.0, 1.25, 1.5. 1.75. 2.0. 2.25. 2.5, 2.75. 3.0. 3.25, 3.75. 4.0, 4.25, 4.5. 4.75. 5.0. 5.25. 5.5, 5.75, 6.25. 6.5. 6.75, 7.0. 7.25. 7.5. 7.75, 8.0, 8.25, 8.75. 9.0. 9.25, 9.5. 9.75. 10.0. 6 9.0 0.5. 1.0, 1.25, 1.5. 1.75. 2.0, 2.25, 2.5, 2.75, 3.0, 3.25, 3.75, 4.0, 4.25. 4.5. 4.75, 5.0. 5.25, 5.5, 5.75, 6.25. 6.5. 6.75. 7.0, 7.25. 7.5. 7.75. 8.0. 8.25. S8.75. 9.0. 9.25. 9.5. 9.75. 10.0. 7 8.75 0.5. 1.0. 1.25, 1.5. 1.75. 2.0. 2.25. 2.5. 2.75. 3.0, 3.25, 3.75, 4.0. 4.25, 4.5. 4.75. 5.0. 5.25. 5.5. 5.75. 6.25, 6.5, 6.75, 7.0, 7.25. 7.5, 7.75, 8.0. 8.25, 8.75. 9.0, 9.25, 9.5, 9.75. 10.0. Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AUOO/00092 8 8.50 0.5, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25. 2.5. 2.75, 3.0. 3.25, 3.75, 4.0. 4.25. 4.5, 4.75. 5.0. 5.25. 5.5. 5.75, 6.25. 6.5. 6.75, 7.0. 7.25, 7.5, 7.75. 8.0. 8.25, 8.75. 9.0, 9.25. 9.5. 9.75. 10.0. 9 8.25 0.5. 1.0. 1.25, 1.5, 1.75, 2.0. 2.25, 2.5. 2.75, 3.0, 3.25, 3.75. 4.0. 4.25. 4.5. 4.75. 5.0. 5.25. 5.5, 5.75, 6.25. 6.5. 6.75. 7.0. 7.25. 7.5. 7.75. 8.0, 8.25, 8.75, 9.0. 9.25, 9.5. 9.75, 10.0, 8.00 0.5. 1.0, 1.25. 1.5. 1.75. 2.0. 2.25. 2.5. 2.75, 3.0. 3.25, 3.75. 4.0, 4.25. 4.5, 4.75. 5.0. 5.25. 5.5. 5.75, 6.25, 6.5, 6.75. 7.0, 7.25. 7.5. 7.75. 8.0. 8.25. 8.75. 9.0. 9.25. 9.5, 9.75, 10.0, 1 1 7.75 0.5. 1.0, 1.25. 1.5, 1.75. 2.0. 2.25. 2.5. 2.75. 3.0, 3.25, 3.75, 4.0. 4.25. 4.5. 4.75, 5.0. 5.25. 5.5. 5.75, 6.25. 6.5, 6.75, 7.0. 7.25. 7.5, 7.75. 8.0. 8.25. 8.75. 9.0. 9.25. 9.5. 9.75. 10.0. 12 7.50 0.5, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25. 2.5. 2.75, 3.0, 3.25, 3.75, 4.0, 4.25, 4.5, 4.75, 5.0, 5.25, 5.5, 5.75, 6.25, 6.5, 6.75, 7.0. 7.25, 7.5, 7.75, 8.0, 8.25, 8.75, 9.0. 9.25. 9.5. 9.75. 10.0, 13 7.25 0.5, 1.0. 1.25. 1.5. 1.75, 2.0, 2.25. 2.5.2.75. 3.0, 3.25, 3.75. 4.0. 4.25. 4.5, 4.75. 5.0. 5.25. 5.5, 5.75, 6.25. 6.5. 6.75, 7.0. 7.25, 7.5, 7.75. 8.0, 8.25. 8.75. 9.0. 9.25. 9.5. 9.75. 10.0, 14 7.00 0.5. 1.0. 1.25. 1.5. 1.75. 2.0. 2.25. 2.5. 2.75. 3.0, 3.25, 3.75, 4.0, 4.25. 4.5. 4.75. 5.0, 5.25. 5.5, 5.75, 6.25, 6.5. 6.75. 7.0, 7.25. 7.5, 7.75. 8.0. 8.25. 8.75. 9.0. 9.25. 9.5, 9.75. 10.0. 16 6.75 0.5. 1.0. 1.25, 1.5. 1.75. 2.0. 2.25. 2.5. 2.75, 3.0, 3.25, 3.75. 4.0. 4.25. 4.5, 4.75. 5.0. 5.25. 5.5. 5.75. 6.25. 6.5, 6.75. 7.0. 7.25. 7.5. 7.75, 8.0. 8.25, 8.75. 9.0. 9.25. 9.5. 9.75. 10.0, 17 6.50 0.5, 1.0. 1.25, 1.5. 1.75, 2.0, 2.25, 2.5, 2.75, 3.0, 3.25, 3.75, 4.0. 4.25. 4.5. 4.75. 5.0. 5.25. 5.5. 5.75, 6.25, 6.5, 6.75. 7.0, 7.25. 7.5. 7.75. 8.0. 8.25. 8.75. 9.0. 9.25. 9.5. 9.75. 10.0. Substitute Sheet (Rule 26) RO/AU 1. -11 .11 WO 00/49229 PCT/AU00/00092 18 6 0.5, 1.0. 1.25. 1.5, 1.75. 2.0. 2.25. 2.5. 2.75. 3.0, 3.25, 3.75, 4.0, 4.25. 4.5. 4.75. 5.0. 5.25. 5.5. 5.75, 6.25. 6.5. 6.75, 7.0. 7.25. 7.5. 7.75. 8.0. 8.25, 8.75, 9.0. 9.25. 9.5. 9.75. 10.0. 19 5.5 0.5, 1.0, 1.25. 1.5. 1.75.2.0. 2.25. 2.5. 2.75. 3.0, 3.25, 3.75. 4.0. 4.25. 4.5. 4.75. 5.0. 5.25. 5.5, 5.75, 6.25. 6.5, 6.75, 7.0, 7.25. 7.5. 7.75, 8.0, 8.25, 8.75. 9.0. 9.25. 9.5, 9.75. 10.0. 5 0.5, 1.0, 1.25, 1.5, 1.75. 2.0. 2.25. 2.5. 2.75. 3.0, 3.25, 3.75, 4.0. 4.25. 4.5. 4.75. 5.0. 5.25. 5.5. 5.75, 6.25, 6.5. 6.75, 7.0, 7.25. 7.5, 7.75. 8.0, 8.25, 8.75. 9.0. 9.25. 9.5. 9.75. 10.0. 21 4 0.5, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25. 2.5, 2.75. 3.0, 3.25, 3.75. 4.0. 4.25, 4.5. 4.75. 5.0. 5.25. 5.5, 5.75, 6.25. 6.5. 6.75, 7.0. 7.25. 7.5. 7.75, 8.0, 8.25, 8.75. 9.0. 9.25, 9.5. 9.75. 10.0. 22 3 0.5, 1.0, 1.25. 1.5, 1.75, 2.0, 2.25. 2.5. 2.75. 3.0, 3.25, 3.75, 4.0, 4.25, 4.5, 4.75. 5.0, 5.25. 5.5, 5.75, 6.25. 6.5, 6.75, 7.0. 7.25. 7.5. 7.75, 8.0, 8.25, 8.75, 9.0, 9.25. 9.5, 9.75. 10.0. 23 2 0.5, 1.0, 1.25. 1.5, 1.75, 2.0, 2.25. 2.5 2.75, 3.0, 3.25, 3.75, 4.0, 4.25. 4.5, 4.75. 5.0. 5.25. 5.5, 5.75, 6.25. 6.5. 6.75, 7.0. 7.25. 7.5. 7.75. 8.0. 8.25, 8.75. 9.0. 9.25. 9.5. 9.75. 10.0. 24 1 0.5, 1.0, 1.25. 1.5, 1.75. 2.0. 2.25. 2.5, 2.75. 3.0. 3.25, 3.75. 4.0. 4.25, 4.5. 4.75, 5.0. 5.25, 5.5, 5.75, 6.25, 6.5, 6.75, 7.0. 7.25. 7.5. 7.75. 8.0, 8.25, 8.75, 9.0. 9.25, 9.5, 9.75. 10.0. Typically. the concentration and presence of either calcium lignosulphonate, sodium lignosulphonate and ammonium lignosulphonate further depends on the type of soils used in the present invention, especially for use in sealed surfaces.

Description Of The Preferred Embodiment(s) And Example(s) Of The Invention The following description of the preferred embodiment serves only to further illustrate the present invention and should not be construed as limiting the generality of the above description.

The present invention will now be described, by way of example only, with reference to the accompanying schematic flow diagram: in which: Substitute Sheet (Rule 26) RO/AU I WO 00/49229 PCT/AUOO/00092 21 Figure 1 is a schematic flow diagram illustrating the method of producing a base composition and a sealed surface thereof according to the present invention.

In Figure 1 of the accompanying drawings there is shown a schematic flow diagram of a process according to the present invention. A lignosulphonate composition (10) of calcium lignosulphonate. sodium lignosulphonate and ammonium lignosulphonate is premixed and added to a soil composition (12) either in a container (14) or on a ground surface (not shown).

The lignosulphonate composition (10) and soil composition (12) is mixed by suitable means (16) such as a rotary mixer and water is added to the resulting mixture to orm a road base composition (18) according to the present invention substantially at or about the optimum moisture content for maximum compaction as previously defined.

The road base composition (18) is then compacted to form a compacted road base composition by suitable means (20) such as a road roller which compacts and bonds the particles of the soil together with the assistance of the lignosulphonate composition (12).

The road or base may be profiled so as to drain excess water from its surface or layers.

Typically, after the compacted road base composition is formed after sufficient time in rolling, watering and is of sufficient compaction, and after drying, a sealing composition comprising an asphalt and/or bitumen/bituminous emulsion composition (22) is applied to an upper surface of the compacted road base composition. A bitumen, bituminous emulsion and/or an asphalt composition (24) is then added which forms the sealing road composition according to the present invention. Some asphalt needs hitumen or a bituminous emulsion first before being applied whilst other asphalts and bitumen/bituminous emulsions are able to be applied alone. The surface sealing layer is then formed over the compacted road base composition in the usual manner known to the skilled addressee such as by hot and/or cold rolling.

Further. in another example. concrete is able to be applied over the base composition of the present invention to form a road, pathway, floor and the like surface.

The following examples serve only to further illustrate the present invention and should not be construed as limiting the generality of the above description.

Examples A lignosulphonate compound or a mixture of lignosulphonate compounds defining a first composition comprises the following: A. Calcium lignosulphonate.

B. Sodium lignosulphonate, and C. Ammonium lignosulphonate.

The said first composition includes a mixture of A. B and/or C. with the proviso that there must be at least one of A. B or C present as a single component or in the composition.

Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 22 A second component or mixture of components defining a second composition comprises the following compounds: D. Portland Cement.

E. Hydrated Lime, F. Flyash.

G. calcium Sulphate, and H. Blast Furnace Slag The said second composition includes a mixture of D. E. F. G and/or H with the proviso that there must be at least one of D. E. F. G and/or H present as a single component or in the composition.

The said first and second compositions are blended into a two part product in the ranges as set out below in Table B, according to the requirements of the particular use, whereby for each entry numbered 1 to 24 there is provided a value indicating the proportion (parts by weight) of the First Composition B C) and the Second Composition E. F. G H) which is also indicated by parts by weight.

IS

TABLE B Entry First Second Composition Composition 1 10 0.5. 1, 1.25. 1.50, 1.75. 2.00, 2.25, 2.50, 2.75, 3.00, 3.25. 3.50. 3.75. 4.00. 4.25. 4.50. 4.75. 5.00, 5.25, 5.50. 5.75, 6.00. 6.25. 6.50. 6.75. 7.00, 7.25, 7.50. 8.00. 8.25. 8.50. 8.75, 9.00, 9.25, 9.50, 9.75, 10.0. 2 9.5 0.5. 1. 1.25, 1.50. 1.75, 2.00, 2.25. 2.50, 2.75, 3.00. 3.25, 3.50. 3.75, 4.00, 4.25, 4.50, 4.75, 5.00, 5.25. 5.50. 5.75, 6.00. 6.25, 6.50, 6.75, 7.00, 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00, 9.25, 9.50, 9.75, 10.0. 3 9.0 0.5. 1. 1.25. 1.50, 1.75. 2.00. 2.25. 2.50, 2.75, 3.00. 3.25. 3.50. 3.75. 4.00. 4.25. 4.50. 4.75. 5.00, 5.25. 5.50. 5.75. 6.00. 6.25. 6.50, 6.75, 7.00. 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00. 9.25. 9.50, 9.75, 10.0, Substitute Sheet (Rule 26) RO/AU WO 00/49229 WO 0049229PCT/AUOO/00092 4 8.5 0.5, 1. 1.25, 1.50. 1.75, 2.00. 2.25, 2.50. 2.75, 3.00. 3.25. 3.50. 3.75. 4.00. 4.25, 4.50. 4.75. 5.00, 5.25, 5.50, 5.75. 6.00. 6.25. 6.50, 6.75. 7.00, 7.25, 7.50, 8.00. 8.25. 8.50. 8.75, 9.00. 9.25. 9.50. 9.75, 10.0. 8.0 0.5. 1. 1.25. 1.50, 1.75, 2.00. 2.25, 2.50, 2.75, 3.00. 3.25. 3.50, 3.75. 4.00. 4.25, 4.50, 4.75, 5.00, 5.25. 5.50. 5.75. 6.00. 6.25. 6.50. 6.75. 7.00. 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00. 9.25, 9.50, 9.75, 10.0. 6 7.5 0.5, 1. 1.25. 1.50. 1.75, 2.00, 2.25, 2.50. 2,75, 3.00, 3.25. 3.50. 3.75. 4.00. 4.25 .0 .5 .0 5.25. 5.50. 5.75. 6.00. 6.25. 6.50. 6.75. 7.00. 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00. 9.25, 9.50, 9.75, 10.0. 7 7.0 0.5. 1. 1.25. 1.50. 1.75, 2.00. 2.25, 2.50, 2.75, 3.00. 3.25. 3.50, 3.75. 4.00. 4.25, 4.50, 4.75. 5.00, 5.25. 5.50. 5.75, 6.00. 6.25. 6.50. 6.75, 7.00, 7.25, 7.50, 8.00, 8.25, 8.50. 8.75. 9.00. 9.25, 9.50. 9.75, 8 6.5 0.5. 1, 1.25. 1.50. 1.75, 2.00. 2.25, 2.50, 2.75, .3.00. 3.25. 3.50. 3.75. 4.00. 4.25. 4.50, 4.75. 5.00, 5.25. 5.50. 5.75. 6.00. 6.25. 6.50. 6.75, 7.00. 7.25, 7.50. 8.00. 8.25, 8.50. 8.75. 9.00. 9.25, 9.50. 9.75, 10.0. 9 6.0 0.5. 1, 1.25, 1.50. 1.75, 2.00, 2.25, 2.50, 2.75, 3.00 3.25. 3.50. 3.75. 4.00. 4.25. 4.50. 4.75, 5.00, 5.25. 5.50. 5.75, 6.00. 6.25. 6.50, 6.75, 7.00 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00. 9.25, 9.50. 9.75, 10.0. 5.5 0.5. 1. 1.25. 1.50, 1.75. 2.00, 2.25, 2.50, 2.75, 3.00. 3.25, 3.50. 3.75, 4.00, 4.25. 4.50, 4.75, 5.00, 5.25. 5.50, 5.75, 6.00. 6.25. 6.50. 6.75. 7.00, 7.25, 7.50. 8.00. 8.25, 8.50. 8.75. 9.00. 9.25, 9.50, 9.75, 10.0. Substitate Sheet (Rule 26) 110/AU WO 00/49229 PCT/AU00/00092 11 5.0 0.5, 1. 1.25, 1.50. 1.75. 2.00. 2.25, 2.50, 2.75, 3.00. 3.25. 3.50. 3.75. 4.00. 4.25, 4.50, 4.75, 5.00, 5.25. 5.50. 5.75, 6.00. 6.25. 6.50. 6.75. 7.00, 7.25, 7.50. 8.00, 8.25. 8.50. 8.75, 9.00, 9.25, 9.50, 9.75, 10.0. 12 4.5 0.5. 1. 1.25, 1.50, 1.75, 2.00. 2.25. 2.50. 2.75, 3.00. 3.25. 3.50. 3.75. 4.00. 4.25. 4.50. 4.75. 5.00, 5.25. 5.50. 5.75. 6.00. 6.25. 6.50. 6.75. 7.00. 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00. 9.25. 9.50. 9.75, 10.0. 13 4.0 0.5, 1. 1.25, 1.50, 1.75. 2.00. 2.25, 2.50, 2.75, 3.00. 3.25, 3.50, 3.75, 4.00, 4.25. 4.50, 4.75, 5.00, 5.25. 5.50. 5.75, 6.00. 6.25. 6.50. 6.75, 7.00, 7.25, 7.50. 8.00. 8.25. 8.50. 8.75, 9.00. 9.25. 9.50. 9.75, 10.0. 14 3.5 0.5. 1. 1.25. 1.50. 1.75. 2.00. 2.25. 2.50, 2.75, 3.00. 3.25. 3.50, 3.75. 4.00, 4.25, 4.50, 4.75, 5.00, 5.25. 5.50. 5.75, 6.00. 6.25. 6.50, 6.75, 7.00, 7.25, 7.50, 8.00, 8.25, 8.50, 8.75, 9.00, 9.25, 9.50, 9.75, 10.0. 3.0 0.5, 1. 1.25, 1.50, 1.75. 2.00, 2.25, 2.50, 2.75, 3.00. 3.25. 3.50, 3.75. 4.00. 4.25. 4.50. 4.75, 5.00, 5.25. 5.50. 5.75. 6.00. 6.25. 6.50. 6.75. 7.00, 7.25, 7.50. 8.00. 8.25. 8.50. 8.75. 9.00. 9.25. 9.50. 9.75, 10.0. 16 2.5 0.5. 1. 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, 2.75, 3.00. 3.25, 3.50, 3.75, 4.00. 4.25. 4.50, 4.75, 5.00, 5.25. 5.50, 5.75, 6.00. 6.25, 6.50. 6.75. 7.00, 7.25, 7.50. 8.00, 8.25, 8.50. 8.75. 9.00. 9.25, 9.50, 9.75, 10.0.50.

17 2.0 0.5. 1. 1.25, 1.50, 1.75. 2.00, 2.25, 2.50, 2.75, 3.00. 3.25. 3.50, 3.75, 4.00, 4.25. 4.50, 4.75, 5.00, 5.25. 5.50. 5.75, 6.00. 6.25. 6.50. 6.75. 7.00, 7.25, 7.50, 8.00. 8.25, 8.50. 8.75. 9.00. 9.25, 9.50. 9.75, 10.0, Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 18 1.5 0.5. 1, 1.25. 1.50. 1.75. 2.00, 2.25. 2.50, 2.75, 3.00, 3.25. 3.50. 3.75. 4.00, 4.25, 4.50, 4.75, 5.00, 5.25, 5.50. 5.75, 6.00, 6.25. 6.50, 6.75. 7.00. 7.25, 7.50. 8.00, 8.25, 8.50. 8.75. 9.00, 9.25. 9.50. 9.75, 10.0.50.

19 1.25 0.5. 1. 1.25. 1.50, 1.75. 2.00, 2.25. 2.50, 2.75, 3.00. 3.25. 3.50. 3.75. 4.00, 4.25, 4.50, 4.75, 5.00, 5.25. 5.50. 5.75. 6.00. 6.25, 6.50, 6.75, 7.00, 7.25, 7.50, 8.00, 8.25, 8.50. 8.75, 9.00, 9.25, 9.50, 9.75, 10.0..50.

1.0 0.5, 1. 1.25. 1.50, 1.75. 2.00. 2.25. 2.50. 2.75, 3.00, 3.25. 3.50, 3.75. 4.00. 4.25. 4.50. 4.75, 5.00, 5.25, 5.50. 5.75. 6.00. 6.25, 6.50, 6.75, 7.00, 7.25, 7.50. 8.00. 8.25, 8.50. 8.75. 9.00, 9.25, 9.50, 9.75, 10.0, The two part product which is blended together as shown in Table B above defines a third composition which is then admixed with soil, for example, crushed rock based soil. sand based soil, gravel based soil, other stone or other particulate based soil, clay based. silt based soil or a mixture thereof.

The blends of the Third Composition with Soil is shown as follows in Table C: Table C Soil (weight percent) Third Composition (weight percent) 99.8 0.2 99.7 0.3 99.5 99.4 0.6 99.3 0.7 99.2 0.8 99.1 0.9 99.0 98.9 1.1 98.8 1.2 98.7 1.3 98.6 1.4 98.5 98.4 1.6 Substitute Sheet (Rule 26) RO/AU l-11-1.

WO 00/49229 PTAO/09 PCT/AUOO/00092 98.3 1.7 98.2 1.8 98.1 1.9 98.0 97.9 2.1 97.8 1) 97.7 2.3 97.6 2.4 97.5 97.4 2.6 97.3 2.7 97.2 2.8 97.1 2.9 97.0 96.9 3.1 96.83.

96.7

J

96.6 3.4 96.5 96.4 3.6 96.3 3. 7 96.2 3.8 96.1 3.9 96.0 95.9 4. 1 95.8 4.2 95.7 4.3 95.6 4.4 95.5 95.4 4.6 95.3 4.7 95.2 4.8 95.1 4.9 95.0 94.9 5.1 94.8 5.2 94.7 5. 3 Substitute Sheet (Rule 26) RO/AU WO 00/49229 WO 0049229PCT/AUOO/00092 94.6 5.4 94.5 94.4 5.6 94.3 5.7 94.2 5.8 94.1 5.9 94.0 93.9 6. 1 93.86.

9 3. 76.) 93.6 4 93.56.

93.46.

93.3 6.7 9 3. 2 6.8 93.1 6.9 93.0 92.9 7.1 92.8 7.2 92.7 7.3" 92.6 7.4 92.5 92.4 7.6 9 2. 3 7.7 92.2 7.8 92.1 7.9 92.0 91.9 8.1 91.8 8.2 91.783 91.6 8.4 91.5 91.4 8.6 91.3 8.7 91.2 8.8 91.1 8.9 91.0 Substitute sheet (Rule 26) RQ/AU WO 00/49229 PCT/AU00/00092 28 90.9 9.1 90.8 9.2 90.7 9.3 90.6 9.4 90.5 90.4 9.6 90.3 9.7 90.2 9.8 90.1 9.9 90.0 10.0 As already mentioned water is added as required to bring the moisture content to or about the optimum moisture content for compaction. If too much water is accidently added, the composition can be left to dry out for a time sufficient for the moisture content to drop to at or about the optimum moisture content for maximum compaction. Compaction of the base is then carried out. The details of determining optimum moisture content of the mixture are described below.

Example of determination of dry density/moisture content relationship of base composition The following example demonstrates a method of measuring moisture content o1 which in turn allows the prediction of maximum compaction of the base composition at various moisture contents. The collation of this data will assist in determining the optimum moisture content of the base composition.

In this example a 2.5kg rammer falling through a height of 300mm is used to compact the base composition in three layers into a one litre mould.

1s The base composition is firstly weighed in a prepared sample.

S The mould is weighed with a baseplate attached to Ig, this value being, and the internal dimensions are measured to within 0.1mm.

The extension to the mould is attached and the mould assembly is placed on a base.

by weight. of water is added to the prepared base composition and mixed thoroughly by hand.

A quantity of moist soil is inserted in mould body such that when compacted it occupies a little over one-third of the height of the mould body.

Twenty seven blows from the rammer is dropped from a height of 300 mm above the base composition. distribute the blows evenly over the surface and ensure that the rammer always falls freely and is not obstructed by soil in a guide member formed in the mould body.

Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 29 S The blows are repeated twice so that the amount of base composition used is sufficient to fill the mould body, with the surface not more than 6mm proud of the upper edge of the mould and it is important to ensure that no more than 6mm stands proud.

S The extension is removed and the excess soil is removed and the surface of the compacted soil is levelled carefully to the top of the mould body using a straight edge.

Any coarse particles removed in the levelling process and replaced by finer material from the sample, and well pressed in, the base composition and mould is weighed and with the baseplate to within Ig this value is X 2 S The remainder of the soil is broken up, and mixed with the remainder of the prepared sample. A suitable increment of water (2wt%) is added and mixed thoroughly into the soil, the water added for each stage of the test should be such that a range of moisture contents is obtained which includes the optimum moisture content.

S Typically additions of 1 2wt% are suitable for sandy' gravelly soils and 2 to for cohesive soils, to increase the accuracy of the test it is often advisable to reduce the increments of water in the region of the optimum moisture content.

Typically the above procedure is repeated to give a total of five determinations.

The moisture content of each determination is such that the optimum moisture content is that which the maximum dry density occurs near the middle of the range.

The internal volume V in cm 3 of the mould is calculate as follows.

The bulk density p in Mg/m 3 of each compacted specimen is obtained from the equation X,

X,

p=

V

where X, is the mass of mould and baseplate (in g); where X 2 is the mass of mould, baseplate and compacted soil (in g).

Calculate the dry density Pa in Mg/m' of each compacted specimen from the equation 100, 100 w where w is the moisture content of the soil (in wt%).

The dry densities obtained from a series of determinations are plotted as ordinates against the corresponding moisture contents. A curve of best fit is drawn to the plotted points and the position of the maximum of this curve is identified. The values of dry density are read off to.

On the same graph the curves are plotted corresponding to and 10% air voids, calculated from the equation.

I

1-^ 100 l w p, 100p,,.

Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 Where Pa is the dry density in Mg/m' Where Ps is the particle density in Mg/m 3 assumed equal to 2.65 or 2.70 Where Pw is the density of water in Mg/nrm assumed equal to 1 Where Va is the volume of air voids in the soil. expressed as a percentage of the total volume of the soil (equal to 10% for the purpose of this example).

Where w is the moisture content in wt% An example of optimum moisture content measured and evaluated by the procedures above are as follows.

Soil Sample: ridge grave, brown ex Lemon Tree Passage Quarry Stabilised with a blend containing Lignosulphonate 1 part Cement 2 parts Hydrated Lime 1 part at 80kg per compacted cubic metre Maximum dry density 2.00 tonne per cubic metre Optimum moisture content 11.Owt% However, it should be appreciated that in the field, the optimum moisture content is approximately determined by a hand test where the base composition is compacted in the palm and suitable increments of water are added until the approximate point of maximum compaction is achieved.

The blended compositions of the Third composition and the soil in Table C above ;rc spread on to a ground surface where it is desired to form a base for an unsealed or sealed surface such as a road. pathway, pavement, floor and the like.

A rotary hoe together with a water cart adds water to the composition to achieve optimum moisture content which results in a substantially dust free base since the soil particles are cohesively bonded together.

Alternatively. the Third composition and the soil are also mixed with water in a pug mill mixer which is located alongside, adjacent or at a location remote from the proposed location of the road base.

Further. the Third composition and soil are also mixed are also blade mixed by a grader with the addition of water. The Third composition can also be formed into a slurry to obtain substantially optimum moisture content as previously defined so as to provide maximum compaction to the base composition.

The optimum moisture content for a particular soil or soil composition of the present invention is determined by suitable compaction tests. The compaction tests are used to determine the optimum moisture content at which a particular soil or soil composition has to be compacted in order to attain the maximum dry density. The Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AUOO/00092 31 compaction tests are used to determine the optimum moisture content at which a given soil has to compacted in order to attain the maximum dry density. The laboratory compactive effort is standardized and it is assumed that it duplicates field compaction effort and vice versa. The material is compacted at various moisture contents using a fresh portion of soil for each moisture content applied. As the moisture content increases. dry density increases to a certain maximum but then decreases. Plotting dry densities against moisture contents gives a moisture content density curve corresponding to a given compaction effort. This obviously shows that for each soil there is a given maximum compaction that can be achieved for each moisture content.

to Thereafter suitable compaction and binding by the lignosulphonate composition allows the bitumen and/or asphalt composition to be applied in the case of a sealed base.

The composition of the present example potentially achieves this result up to the range of approximately 50 to 70 percent reduction in costs due to a lesser amount of material being required to form the substantially dust free and cohesively bonded state when compared to the prior art.

After the base for the sealed surface has been formed, a bitumen/bituminous emulsion and /or asphalt is layed over the base to form a sealed surface.

The bond strength between the base composition of the present invention and the asphalt and/or bitumen/bituminous emulsion composition is observed to be increased

EXAMPLES

The objective is to create an impervious, bound, flexible, resilient pavement with the high resilient modulus that will achieve a relatively high "soaked California Bearing Ratio". an improved unconfined compressive strength, and, in the case of sealed surfaces, a high strength bond to bitumen, asphalt, and to the sub grade materials.

Under standard pavement "Atterburg Limits" testing, various mixes will provide high strength. reliable pavements where plasticity indices range 0 to 40, or greater.

Because there is almost an infinite range of soil types in the above classification range, a wide selection of blend variations between the lignosulphonates and some or all of the other materials nominated is required to achieve the high strengths and good to optimal performance and efficiency at the lowest possible costs.

To achieve an efficient and effective, flexible, resilient bound pavement, a dry sieve analysis of the soils to be stabilised is desirable. Ideally the soil has a 15% minimum, and preferably 20% or more sieve fraction less than 0.075mm -0.075mm). If this is not available in the soil then the "other" material selected in the PP product blend is proportionally adjusted to achieve the objective. Lignosulphonates should not be considered as part of the additional fines required.

The most commonly used lignosulphonates are ammonium, sodium and calcium, usually in combinations of two or three. They are required for four purposes Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 32 1. to act as a flexible, high strength, resilient binder 2. to react with the soil, cement, and lime and the other material to provide chemical stability, and therefore soil stability 3. With the other materials, they bind the soil to form an impervious mass with a very high level of water resistance 4. The blended impervious mass forms its own carbonaceous "primer" to bond strongly to bitumen or asphalt Soil stabilisation procedures are basically the same as when lime, cement, slay, flyash, etc are mixed in individually, or in combination blends into soil. Moisture is controlled to to modified optimum and the pavement is compacted to the maximum practical level.

Good compaction is critical to the process, and it is not difficult to achieve high density and compaction levels in excess of 100%. Other advantages are the ease of compaction and the ability to achieve very high densities.

Commonly, lignin percentages for most road materials are 0.5% to 2wt%. However, soil tests may reveal the need to go outside this range.

Stabilisation depths for public roads (sealed or unsealed) are commonly in 100mm to 200mm range, more typically 150mm to 200mm, but sometimes greater e.g. 200- 350mm or 200 -250mm, or 200 -300mm.

Summarising design of the blend as per PP is achieved by taking into account the following factors and blending and laboratory testing to achieve the most economic best hind performance.

The factors Traffic loading and type Climate Soil type Sub grade of pavement Type of surface finish or seal 1. Highway blend designed for in excess of 1000 heavy vehicles per day and assuming area subject to periodic flooding: Base soil high clay content plasticity index 15 to 20 average soaked CBR 13.5 (98wt% soil+water in an amount where the base composition is substantially at or about an optimum moisture content that enables substantially maximum compaction of the base composition).

Sub grade soil high clay content plasticity index 20 to 40 average soaked CBR Rehabilitation of 1km of 11 m wide road with a blend to a depth of 200mm in base Blend lwt% (50/50) ammonium lignosulphonate and sodium lignosulphonate, 1% general purpose cement, lwt% hydrated lime 2. Designed for public highway heavy traffic Substitute Sheet (Rule 26) RO/AU WO 00/49229 PCT/AU00/00092 33 Base soil medium clay content with plasticity index 8 to 15 (98wt% soil+water in an amount where the base composition is substantially at or about an optimum moisture content that enables substantially maximum compaction of the base composition) to depth 200mm.

Blend lwt% (one third each ammonium, sodium, calcium lignosulphonates), general purpose cement and 0.5wt% hydrated lime.

3. Designed for public highway, heavy traffic Base soil gravel with very low plasticity index (98wt% soil+water in an amount where the base composition is substantially at or about an optimum moisture content to that enables substantially maximum compaction of the base composition) Construction/rehabilitation depth -150mm.

(50/50 ammonium sodium lignosulphonate) bentonite general purpose cement 0.5wt% hydrated lime 4. Architectural Pavement High strength hard wearing decorative image pavement.

Base soil decomposed granite with very limited fines and zero plasticity index Stabilisation to high strength hard wearing pavement using a blend of lwt% (50/50 ammonium lignosulphonate/sodium lignosulphonate), lwt% bentonite, lwt% hydrated lime, 2 wt general purpose cement.

The advantages of the compositions and methods of the present invention are potentially as follows: -environmentally friendly compositions with a very low LD 50 which are substantially non-toxic and non-carcinogenic: -in the case of a sealed base. useful in a wide variety of sealed surfaces from pavers, pathways. roads, floors and the like; -in the case of an unsealed base, useful in a wide variety of unsealed surfaces from pavers. pathways, roads, floors and the like: -a stronger base with a strength of potentially up to 35mPa which is useful for sealed and unsealed surfaces: -useful for a wide variety of soils including but not limited to clay based and silt based soils: IThe processes and compositions of the present invention typically leads to the lollowing advantages compared with known compositions and methods.

Potentially increased wear of asphalt/bitumen/bituminous emulsion composition fbr sealed surfaces especially roads: and Substitute Sheet (Rule 26) RO/AU I WO 00/49229 PCT/AU00/00092 34 a stronger base for sealed surfaces which produces a highly resilient, shock absorbent surface with increased strength to withstand dynamic stresses imported to said sealed surfaces.

increased speed of laying down road base.

potentially 50 to 70 percent cost reduction in the amount of binding composition required for unsealed surfaces such as loose dirt. gravel and clay based road bases: increased wear of unsealed roads: and a stronger base for unsealed surfaces which produces a highly resilient, shock absorbent surface with increased strength to withstand dynamic stresses imported to said io surtaces.

increases speed of laying down base for unsealed surfaces.

Modifications and variations such as would be apparent to a skilled addressee are deemed to be within the scope of the present invention. It is also to be understood that the present invention should not be restricted to the particular embodiment(s) or example(s) illustrated under the description of the preferred embodiment of the invention.

Throughout the specification, unless the context clearly indicates otherwise, the word. "comprise", "comprises", "comprising" or other variations thereof shall be understood as meaning that the stated integer is included and does not exclude other integers from being present even though those other integers are not explicitly stated.

Substitute Sheet (Rule 26) RO/AU

Claims (5)

1. A base composition for use in preparing a base for a road, pavement or the like, comprising: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; from 20 wt% to 50 wt% of an additive selected from the group consisting of lime and hydrated lime; and from 20 wt% to 60 wt% of cement, with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

2. A base composition for use in preparing a base for a road, pavement or the like, comprising: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; and from 40 wt% to 80 wt% of a combination of cement and an additive selected from the group consisting of lime and hydrated lime, wherein the cement in said combination is present in an amount up to 90 wt% of the combination, with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

3. A base composition for use as a base for a road, pavement or the like, comprising: from 0.8 wt% to 2 wt% of a compound selected from the group consisting of 25 lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; from 0.25 wt% to 2.5 wt% of an additive selected from the group consisting of lime and hydrated lime; from 0.5 wt to 5.0% wt% of cement; and 30 from 75 wt% to 99.7 wt% of soil, with the proviso that the composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length.

4. A base composition for use as a base for a road, pavement or the like, comprising: [R:\libz]41681.doc:SAK i; a binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; a combination of cement and an additive selected from the group consisting of lime and hydrated lime, wherein the cement in said combination is present in an amount up to 90 wt% of the combination; and soil, wherein the binder is present in an amount between 20 and 60 wt% of the total amount of the compound and the combination and the soil is present in amount between 75% and

99.7% of the total amount of the composition, with the proviso that the base composition does not comprise more than 0.2 wt% mineral or vegetable fibres of between 5 and length. A base composition according to any one of claims 1 to 4 wherein the cement is Portland cement. 6. A base composition according to claim 3 or claim 4 wherein the soil has a plasticity index in the range of 0 to 7. A base composition substantially as hereinbefore described with reference to any one of the Examples. 8. A composition comprising: a composition according to any one of claims 1 to 7 which comprises soil, and a sealant. 9. A composition according to claim 8 wherein said sealant comprises one or more materials selected from the group consisting of asphalt, bitumen and bituminous emulsion compositions. 210 A road, pathway or pavement comprising a composition according to claim 8 25 or claim 9. 11. A process for producing a base for a road, pavement or the like, comprising mixing: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium 30 lignosulphonate and mixtures thereof; from 20 wt% to 50 wt% of an additive selected from the group consisting of lime and hydrated lime; and from 20 wt% to 60 wt% of cement with the proviso that the process does not comprise adding more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length. [R:\libz]41681 .doc:SAK 37 12. A process for producing a base for a road, pavement or the like, comprising mixing: from 20 wt% to 60 wt% of at least one binder selected from the group consisting of lignin, ammonium lignosulphonate, sodium lignosulphonate, calcium lignosulphonate and mixtures thereof; and from 40 wt% to 80 wt% of a combination of cement and an additive selected from the group consisting of lime and hydrated lime, wherein the cement in said combination is present in an amount up to 90 wt% of the combination, with the proviso that the process does not comprise adding more than 0.2 wt% mineral or vegetable fibres of between 5 and 20mm length. 13. A process for producing a base for a road, pavement or the like, comprising mixing a base composition according to claim 1 or claim 2 with soil wherein soil comprises between 75 and 99.7 wt% of the total amount of soil and said base composition. 14. A process according to any one of claims 11 to claim 13 wherein the cement is Portland cement. A process according to claim 13 wherein the soil has a plasticity index in the range of 0 to 16. A process for producing a base for a road, pavement or the like according to any one of claims 13 to 15, wherein the base composition additionally comprises sufficient bentonite to raise the fines level of the soil to at least 10%, said fines not 0000 including the binder. 17. A process for producing a base for a road, pavement or the like, substantially S. as hereinbefore described with reference to any one of the Examples. 25 18. A process for making a composition or a road, pathway or pavement comprising the steps of: treating soil with a composition according to claim 1 or claim 2; compacting the composition to form a base having an unsealed surface; and adding a sealing layer of sealant comprising one or more materials selected from the 30 group consisting of asphalt, bitumen and bituminous emulsion compositions over the base. 19. A base composition when made by the process of any one of claims 11 to 17. 20. A composition or a road, pathway or pavement when made by the process of S.oo claim 18. [R:\libz]4168 21. A composition according to any one of claims 1Ito 10 when used for making a road, pavement or the like. Dated 10 November, 2003 Wesco Technologies Pty Ltd Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON 0 0 0 0 0 0 to**: R:\Iibz]41681 .doc:SAK