Information Booklet 18-7

Driveways, Tennis Courts · & Coloured Asphalt

Driveways, Tennis Courts & Coloured Asphalt

CONTENTS

Introduction . .. . ............ ...... ... ...... ..... .... .. . ... .. . .. . .. . .. . .. ...... 1 Asphalt Driveways .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 3 Asphalt Tennis Courts ........................ .. ...................... . 6 Colour photographs ......... .................... .... .. .. .... ........ 8, 9 Coloured Asphalt ...... ... ........ .. ......... ...... ...... .... ..... ... ...... 10 Sample specification for small asphalt works .. .. .... .. ..... 13

Introduction

Although asphalt is predominantly black, and is predomi­nantly used in the construction and maintenance of roads, this most versatile of all paving materials can also be produced and laid in attractive colours , and can be used in a number of domestic applications.

This booklet provides an introduction to the use of asphalt in residential driveways and tennis courts, and discusses the benefits of coloured asphalt surfaces for both public and private applications. It also contains a sample specification for calling for tenders for small asphalt works.

Other booklets in this series cover the manufacture of asphalt, the placing of asphalt in a pavement, recycling of asphalt materials and the use of sprayed seals.

DISCLAIMER Mhough the information contained in this guide is believed to be fundamentally correct the Austral ian Asphalt Pavement Associa­tion does not accept any contractual tortious or other form of liability for its contents or for any consequences arising from its use. 1

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An attractive driveway entrance to your home or office is an asset. Each year hundreds of asphalt paved driveways are constructed to lend charm and utility to any homesite at a reasonable cost.

This booklet has been prepared by the Australian Asphalt Pavement Association to assist you in obtaining a quality hot-mix asphalt driveway.

Asphalt provides a smooth, quality , long-lasting surface which may be black or coloured to your requirements , The surface is resilient underfoot, has no joints like concrete , does not reflect glare, provides a hard surface and is easily kept clean by sweeping and hosing down. Small areas which may be damaged can be readily patched and should it be necessary to dig up part of the driveway for alterations the driveway can be quickly and economically repaired and successfully blended in with the existing surface.

TYPICAL RESIDENTIAL DRIVEWAY

Your driveway needs good design and quality construction to provide adequate strength and drainage to carry the traffic loadings. The heavier the loadings and the more repetitions of the traffic , the thicker, or stronger, the pave­ment required . A typical residential driveway is shown in

Fig. 1 for car traffic.

DESIGN AND CONSTRUCTION CONSIDERA­TIONS

For the successful design and construction of a driveway the following points should be considered :

minimum 25 mm compacted thickness

minimum 100 mm compacted thickness. More for weak ground or heavier traffic

Figure 1: Design for typical residential pavement

Asphalt Driveways

1. Pavement depth

The ground on which the driveway is to be laid will dictate the thickness of the base course required . Provided the subgrade is a well -drained, firm clay a 1 OOmm compacted thickness of crushed rock or good quality natural gravel with a 25mm minimum asphalt surfacing will suffice . Avoid the use of granular pavement materials which have high pro­portions of plastic or clay substances.

If the subgrade is a heavy clay or is likely to be used by truck traffic then thicker pavements are required , e.g . minimum 150mm crushed rock or good quality natural gravel with 30mm minimum asphalt surfacing. Thicknesses of 30-40mm will provide a more durable surfacing. Commercial or industrial driveways should be designed by a person experienced in pavement design. Typical asphalt pave­ment requirements for well-drained (CBR 5) residential applications are given in the following table .

Typical asphalt and basecourse Full depth

Traffic pavement asphalt

Foot and bicycle 25mm AC5 75mm AC5 only 100mm base

Light 30mm AC7 or 10 100mm AC 150mm base 10/14

Medium 35mm AC10 125mm AC 200mm base

ASPHALT SURFACING- placed hot and compacted immediately to provide smooth, waterproof running surface

10/14

CRUSHED ROCK OR NATURAL GRAVEL ROAD BASE to provide strength and spread wheel loads

NATURAL OR SELECTED GROUND SUBGRADE shaped to free draining slope and compacted prior to laying base material

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Asphalt Driveways

2. Drainage

The major problems with driveways are caused by water infiltration due to poor surface or subsurface drainage. Subgrade should be sloped (1 in 60 desirable minimum slope) to allow free drainage of pavement layers with no depressions which may trap water and soften subgrade.

(a) Subsurface drainage

In poorly drained area~ which have clay or other moisture susceptible subgrades, subsurface drainage may be re­quired.

(b) Surface drainage

The driveway should be sloped to provide for fast removal of surface water. To avoid pools of water on the driveway the surface should slope at least 1 in 60 (or 50mm in 3 metres).

3. Weed Growth

Some weeds or natural grasses, such as nut grass, kikuyu, couch grass, buffalo grass and bracken ferns, or seeds from trees such as Southern Hackberry, Celtis (Celtis Australis), will grow through hot-mix asphalt unless totally killed be­forehand . An appropriate soil steriliser may be required to prevent this and should be applied uniformly to the subgrade before the pavement is constructed.

4. Width

Should be at least 2114 metres. Where the drive is used as a combination driveway and entrance, a width of 3 metres is recommended.

5. Edging

Concrete masonry or timber should be used or the surface may crack and crumble at the edges. Where edging is not provided the seal must be supported by a pavement shoul­der of at least 300mm on each side to support the asphalt and prevent pavement movement with resultant edge cracking.

6. Tree Roots

Some trees have large, aggressive root systems which can spread under the pavement and edging and remove mois­ture from the underlying soil causing the pavement and edging to move and crack. Your local plant nursery may be able to assist in selecting suitable species of trees, or advising whether existing trees are likely to be a problem to your proposed asphalt driveway.

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7. Hot-Mix Asphalt

The hot-mix asphalt for the surface course must be manu­factured to exact proportions using quality aggregates and spread and compacted while hot by an experienced con­tractor to achieve a good job. The asphalt work should not be done in cold, windy or wet conditions as thin layers of asphalt (30mm or less) cool rapidly in these situations and will not be compacted adequately, thereby being porous, lose strength and have a reduced life.

An asphalt mix of small nominal size (AC5 or AC7) with a relatively high bitumen content (6-6.5% by weight) is preferable and suitable for light traffic. For heavier traffic an AC10 asphalt mix may be used with 30-40mm minimum compacted depth.

8. Cold-Mix Asphalt

Cold-mix asphalt is normally used for filling potholes and patching, and unless specifically designed and handled correctly, is not really suitable for driveway construction. It may be suitable for paths around the house or minor patching of existing driveways.

QUOTATIONS AND PRICE

Remember that a quotation means nothing unless you know exactly what has been provided for in terms of adequate base, surface drainage, etc. You should insist on a written quotation with complete details, such as thickness, material types, quantities, areas and any special require­ments. You get what you pay for- the cheapest price may not produce the best job.

Before accepting a quotation you should establish that the contractor is an experienced, reputable firm that can do a good job and give any necessary after-sales service. Some ways of establishing this are to investigate the following:

• Is the firm listed in the Yellow Pages under "Paving -asphalt and/or bitumen'?

• Are they prepared to let you speak with other custom­ers of theirs and let you look at their workmanship?

• Are they recommended by friends? • Are they prepared to sign and conform to a simple

specification and contract like the one in this booklet? • Are they prepared to give you a guarantee on the

materials and workmanship?

CONSTRUCTION SEQUENCE

Ensure the contractor or his competent supervisor is on site during the progress of the job. The normal sequence is as follows :

• Clear topsoil • Install drains, as necessary

• •

• •

•

•

Check influence of tree roots

Excavate to requ ired depth, remove and replace soft spots

Apply weedkiller/steriliser, if required

Compact subgrade to a smooth , free draining, even slope

Form edges of driveway with a concrete , masonry or timber edging

Place and compact roadbase material to provide an even and well-compacted surface of the correct thickness

• Spray tack coat of bitumen emulsion

Place hot-mix asphalt on the road pavement. pref­erablywith a small paver, if access allows, to obtain a smooth surface. For irregular areas, or where a paver cannot be used, the hot asphalt should be raked to the required depth (usually 29-30mm loose depth for a 25mm minimum compacted depth) and compacted immediately (within 10 min­utes) with a suitable roller. Avoid doing asphalt work on cold, windy, wet days. After rolling and cooling the asphalt surface can be driven on imme­diately, though it may be relatively soft for some days, particularly in hot weather.

PROTECT YOUR ASPHALT DRIVEWAY

Following the satisfactory completion of the work there are a few steps that you , as the owner, can take to make sure that your driveway remains unblemished.

Over the first one or two summers the asphalt surface will , in hot weather, be a little prone to marking or indentation if you leave heavy objects with high point loads on the surface (i.e. sharp objects , rims of drums, chair legs, stilletto heels). Avoid placing sharp objects on the new asphalt in hot weather

Hot car tyres may cause indentations and power steering will sometimes scuff the surface if the stationary tyre is turned on the spot.

A little "good housekeeping" will alleviate these problems. For instance, if you are having a lot of cars to a party , prior to the guests' arrival, hose down the driveway to cool it. Normally this condition , called mix tenderness , disappears after the first or second summer as the mix stiffens up with time.

If mix tenderness persists, even in cool weather, it may be an indication of inadequate compaction and you should seek advice from the contractor who did the work.

Asphalt Driveways

Oil and petrol spills must be avoided because they will tend to dissolve the bitumen in the asphalt mix and lead to the stone particles becoming loose. If accidental spillage does occur then dust with lime or flush gently with a bucket of water to dilute the spill.

MAINTENANCE

A quality hot-mix asphalt driveway built according to proper specifications by a reliable contractor will last for many years . After about 15- 20 years it may require a thin re­surfacingwhichwill completely renew the surface and make it like new again .

RESURFACING EXISTING DRIVEWAYS

Renewal of the surface when necessary may be accom­plished rapidly and economically with minimum interfer­ence to traffic. There are several questions which need to be considered before resurfacing:

1 . What is the condition of the existing surface?

2. Is the base as good as the specification for a new driveway? If not it may need strengthening.

3. Are there any potholes, damage etc? Areas which have a tendency to become soft or spongy must be removed all the way down to the clay and repaired with appropriate base materials which are well compacted to avoid future settlement problems.

4. Drainage deficiencies in existing pavement and surfacing,

5.

6.

Are there any weeds or grass growing through the driveway? If so , chemicals must be applied to make sure that they will not sprout through the new surface.

Damage to existing pavement and surfacing due to trees and subgrade movement. Is crack repair or cold milling of the existing surface required first?

Resurfacing with hot-mix asphalt is carried out by applying a tack coat of bitumen emulsion to the prepared surface and laying and compacting the asphalt while hot.

ACHIEVING A PERFECT JOB

To achieve a quality, long-lasting , attractive driveway which is an asset to your property it is essential to spend time to adequately specify the material requirements for the site , and to have the work done by competent contractors using high quality materials and construction practices, keeping in mind the points raised in this booklet.

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Asphalt Tennis Courts

Asphalt is the ideal surface for today's tennis courts.

Whether you're a champion or strictly a social player, you'll appreciate the smooth surface, true bounce and long­lasting good looks of your all-new, all-weather, low mainte­nance asphalt tennis court .

This brochure describes the recommended steps in the preparation and construction of an asphalt tennis court, and is designed to help you achieve the best possible result and years of enjoyable, trouble-free play. Where the court is to be finished with a synthetic coloured finish , this should be according to the manufacturer's specification (see details below).

Layout & Dimensions

The paved area of a tennis court is usually about 33.5 metres by 16.5 metres (championship courts are usually 36.6 metres by 18.3 metres), giving ample room outside the lines of a doubles court, which has linemarked dimensions of 23.8 metres by 11 metres.

The entire surface of each court should be in one plane. The slope of the final surface should be 1 in 100 to 1 in 120 to allow for drainage of the surface.

Preparation

The subgrade should be excavated, trimmed and rolled to final subgrade levels and, after removal of all roots, etc., compacted to a minimum of 95% Proctor density. If weeds

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have been growing on the site, or there is the possibility of seed falling on the exposed foundation, an appropriate weed killer should be applied to the surface of the prepared subgrade at a rate recommended by the manufacturer.

Attention should also be paid to:

(i) The provision of adequate base and subsoil drain­age. Where the subgrade contains clay or plastic fines the drainage must be such that the subgrade is maintained at a constant moisture content.

(ii) The provision of vehicular access to enable materi­als to be delivered direct to the site and to permit the use of appropriate placing and compaction equip­ment.

(iii) Ensuring that the subgrade material is free of exces­sive salts, in particular in areas where soil salination is a known problem. Measures should also be taken to ensure that any imported base material is also salt free, as the presence of salt will, in time, have a detrimental effect on the adequacy of the finished pavement.

Kerbing

The perimeter of the area should be protected by a durable timber or concrete edging. Minimum size of timber shouid be 1 OOmm x 50mm with 50mm x 13mm pegs at 1 .5 metre intervals. Flush concrete edging should be approximately 150mm x 150mm.

36.6m

23.77m J I

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5.5m J -I

6.4m I L ....

I I I I I I

Playing surface construction

Asphalt tennis courts can be constructed using one of the two techniques detailed below. Option A is a less costly alternative and normally does not result in as precise a finished surface as Option B.

Option A: Base Course

The prepared subgrade is overlaid with a mm1mum of 1 OOmm compacted depth of Fine Crushed Rock or other gravel conforming to the requirements of an A 1 pavement material. Surface tolerance should be plus or minus 10mm from design levels with no variations greater than 1 Omm under a 3 metre straight edge.

Option B: Base and Levelling Course

(a) Granular Base Layer The prepared subgrade is overlaid with a minimum of 75mm compacted depth of Fine Crushed Rock or other gravel conforming to the requirements of an A 1 pavement mate­rial. Surface tolerance should be plus or minus 14mm from design levels with no variations of greater than 14mm under a 3 metre straight edge.

(b) Asphalt Levelling Course Over the base course a 25mm thick binder course of hotmix asphalt is laid to the required slope and grade with no variations greater than 1 Omm under a3 metre straight edge. Maximum size of aggregate should be IOmm.

Surface Course

A final wearing surface course of fine hotmix asphalt is laid, with compaction of the surface continuing until all roller marks and ridges are eliminated. The asphalt is to conform to Australian Asphalt Pavement Association Handbook No. 1. Aggregate should not exceed 1 Omm maximum size and course thickness should be a minimum of 25mm. Net sleeves to be installed at this stage.

When Option A is selected, surface tolerance should be within plus or minus 8mm of design levels, with no variation greater than 8mm along a 3 metre straight edge laid in any direction.

100 X 50 TIMBER EDGING

150 X 150 CONCRETE KERB

Asphalt Tennis Courts

For Option B, surface tolerance should be within plus or minus Smm along a 3 metre straight edge laid in any direction.

Synthetic Colour Finish

Synthetic coloured finish should be applied in accordance with the manufacturer's specification . The following is a general guide on the application of the final colour surface.

Firstly , it is important that the new asphalt surface be left to cure , preferably for 14-28 days. Prior to the application of the colour surfacing the entire court should be flooded . Any areas holding water greater than 3mm deep should be filled with a manufacturer-approved surface restorer. When dried , these areas should be scraped and blown clean. Two applications of filler should be squeegee-applied in accord­ance with your colour requirements. Each coat should be scraped and blown clean . Finally , one application of sealer should be squeegee-applied.

Lines

Lines conforming to the Lawn Tennis Association of Aus­tralia standards should be laid out with appropriate line paint.

General

Upon completion, the contractor should remove all contain­ers , surplus materials and debris associated with the con­tractor's activities, and leave the site in a clean and tidy condition.

PERIMETER KER 8

COLOURED SYNTHETIC SURFACING

SUB GRADE

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Coloured Asphalt

Why use a coloured surface?

Coloured pavements can fulfil several functions:

• Alert traffic to special situations (crossings, cycle paths, bus stops, one-way traffic entrance, danger­ous factory exits) and different pavement functions, (parking areas, bus lanes) ;

• Improve the effect of illumination by the use of light coloured surfaces (tunnels, flyovers) ;

• Increase attractiveness and status of recreational pavements (tennis courts, playgrounds, park lanes, drives, sports fields- both indoors and outdoors) ;

• Diminish or enhance the contrast of asphalt with the surrounjing soil or vegetation by blending it into the landscape.

Coloured surfacings

The appearance of traditional bituminous surfacings, espe­cially when finished with the normal contrasting white lines, is generally very pleasing to the eye. However, there are some locations where a specific colour is desired and there is a number of ways that this can be achieved:

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•

•

•

Application of suitably coloured aggregates to the surfacing during spray sealing ;

Application of a coloured surface treatment after laying conventional asphalt e.g. coloured slurry surfacing;

Using a conventional bitumen with a coloured aggre­gate and/or coloured pigments in hotmix asphalt;

Using a suitably coloured aggregate and/or coloured pigments with a translucent binder in hotmix asphalt.

Selection of Surfacing/Pavement Type

The type of surfacing or pavement selected depends on the traffic type , available materials, and economic considera­tions.

Spray sealing using coloured aggregates is the most eco­nomical coloured surface treatment for lightly trafficked roads and car parks, whilst conventional and translucent binder coloured asphalt provide surfaces more suitable for higher speeds and heavier traffic loads.

Slurry seals can provide a smooth but skid resistant finish

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over existing pavements and should be considered where there is a requirement for a surface free of loose stone and/ or a need to fill minor surface depressions. It is best used for lighter trafficked situations such as housing estate roads , footways , bicycle paths and car parks.

Asphalt surfaces can generally resist scuffing by slow moving turning traffic better than spray sealed surfaces. Coloured asphalt surfaces can be laid in any standard mix design for pavements or driveways. However the consist­ent texture provided by asphalt of nominal size 5-7mm or open-graded mixes will give a surface appearance least affected by reflected light.

Coloured mixes are manufactured either by using coloured aggregates or by adding pigment, usually iron oxide, during the mixing process. Appropriately coloured aggregates should always be used where available to ensure that, when aggregate is exposed after trafficking, the overall appear­ance of the material is maintained. The main drawbacks to colouring mixes using conventional bitumens are:

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•

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•

•

•

•

•

The range of serviceable colours that can be achieved is normally limited to red or brown ;

The quantity of iron oxide required to achieve an acceptable red is high, increasing the cost of the mix substantially.

The aggregate is also important. Coloured aggre­gates to match the oxide will help to maintain consist­ent colour as the pavement wears.

Oxides used must be heat stable at the mixing temperature. Iron oxides in red and yellow are the most stable oxides but care needs to be taken with these oxides as well. Iron oxide yellow is a ferrous hydroxide which is converted into iron oxide red, and drives off vapour at above 180°C. Once 180°C is exceeded reddish discolorations are observed. Iron oxide brown is a mixture of iron oxide black, red and yellow and is likewise temperature susceptible above 180°C.

Titanium dioxide can be used to enhance and lighten any colours but the grade used should be made from the rutile grade not anatase grade. '

The quantity of oxide used is dependent on colour intensity and the aggregate used.

The use of coloured aggregate in combination with a translucent binder and without (added) pigment is often sufficient to produce coloured asphalt.

With translucent binders it is in the interest of economy to make the mat as thin as possible whilst maintain­ing the engineering integrity of the mix.

• Nominal 20mm thick layers of coloured asphalt on 25mm thick black asphaltic concrete can be used as can a 25mm thick coloured layer direct onto the road base. Because of the thin layers, the work should be carried out in good weather and immediately com­pacted while hot.

Repairs

By using a cutback or an emulsion that is compatible with the pigment, and by incorporating the resultant coloured binder with aggregate in a small concrete type mixer, a material suitable for pavement repairs can be made. The proportion of dye or oxide in any mixes made should be filed away for such a requirement.

If trenches are being cut across a coloured pavement the asphalt should be carefully cut out and patched with match­ing material after the work is finished.

The joints should then be sealed by applying an emulsion mix such as that described above, and pouring them into the joint.

Protection of the pavement

During the early life of the pavement , avoid placing sharp objects on the surface, making tight turns with power steering during hot weather, or tracking clay onto the surface.

There are a number of proprietary products on the market to protect surfaces from oil spills or other substances and there is also a range of anti-graffiti fin ishes. The investment would be money well spent for locations subject to oil and fuel spillage.

Life Cycle

The pigmentable bitumen and conventional black bitumen with the oxides will last as long as standard hot-mix asphalt.

General Note

Intending users of coloured asphalt/surfacings should seek advice from manufacturers/suppliers on the type and appli­cation of their products.

Coloured Asphalt

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SPECIFICATION FOR SMALL ASPHALT WORKS

1. This specification is for the construction of:

.... ... ...... ................ .. ............ ... ... .... .. ..... .. .. .. ...... ... ............. .... ..... ....... ............. .. .. ... ..... (driveway, pathway, others?)

2. The owner is : ......... ............. .... .... .... ....... .... .... .. ... ..................... ... .... .................................... ..... ... . ....................... .

Address of works: .......................................................... ...... ..... ............... ...... .... ... ... ... ....... .

Telephone number: ............................ ......................... ...... .. ... ...... ..... ... ....... ...... .... ... ... ... .. ..

3. The contractor is : ............. ............................................. ... .... ... ......................... ... ......... ..... .. ... .. .. ...... ............. ..... ..

Address : .. ....... .... ........ ..... ..... ........................................... .... .... ....... ............. ... ......... ........ ............. .. ............ ......... .

Telephone number: ... .. ..... ...... .. ............. .. ............................. ... .. .. .. ..... .................................. ....... .. .................... .

4. Levels and Grade:

The contractor will provide pegs to establish the finished level of the pavement as dictated by the owner and to provide a basis for the accurate finishing of all the pavement layers, to level , thickness and location. The finished surface should be free draining .

5. Pavement Thickness:

On the prepared subgrade a crushed rock base course shall be placed , spread and compacted to a minimum thick-ness of ............. mm (100mm minimum).

On the prepared crushed rock base the asphalt surfacing shall be placed , spread and compacted to a minimum thickness of ..... .. .... .. mm (e.g. 25mm minimum).

6. Equipment, Materials and Labour:

The contractor shall provide all the necessary equipment, tools, materials and labour to complete the works in accordance with this specification .

7. Smoothness:

Surface smoothness may be measured by placing a 3-metre straight edge on the finished surface and measuring irregularities at the centre of the straight edge. The following irregularities are tolerable on sections of uniform grade or slope.

(a) machine laid work : 7mm (b) hand laid work: 10mm

8. Materials and Manufacture:

The materials used in the construction of this pavement shall comply to the following Australian Standard Specifica­tions guides in their present revised form :

AS 2008 Residual bitumen for pavements AS 2150 Asphalt (hot mixed) Crushed Stone Association : A Guide to Quarry Products

9. Preparation of Subgrade:

The subgrade shall be graded to provide a free draining slope without depressions which may trap water and compacted to a minimum of 95% of maximum dry density (95% MOD) by AS test 1289 (standard compaction). Any soft spots shall be brought to the attention of the owner and shall be excavated and replaced with the best avai lable spoil from on-site. If this proves to be inadequate, su1table material may be imported under conditions negotiated with the owner.

10. Subgrade Drainage:

In poorly drained areas which have clay or other moisture-susceptible subgrades, subsurface drainage may be required . The level of the subsurface drain should be a minimum 300mm below the subgrade level and provided with a free outlet to a stormwater drain or channel.

The subsurface drain may be either 80mm earthenware pipes with gaps suitably covered or 50mm slotted PVC pipe or other approved products on the market. The trench shall be a minimum 150mm wide and shall be backfilled with one size screenings of nominal size between 14mm and 20mm to the top of the crushed rock base course.

11 . Subgrade Sterilisation:

The subgrade soil shall be sterilised if specified by the owner. Steriliser shall be applied at a rate specified by the manufacturer by a method which will ensure a total and uniform coverage of the spec1f1ed area.

12. Preparation of Crushed Rock Base Course:

The crushed rock base course shall be supplied, spread, graded to level and compacted. Care shall be taken to ensure that the surface level is sufficiently accurate to ensure that the finishing asphalt surface is of the specified minimum thickness.

The minimum compacted density on the crushed rock base shall be 95% MOD by AS test 1289 (modified compaction) .

13. Asphalt Surfacing:

To be carried out in accordance with the recommendation of AS 2734 "Asphalt (Hot-Mixed) - Guide to Good Practice:·

Mix selection will be as suggested in AS 2734, generally a mix with a small nominal size and high bitumen content is preferable (AC5 or AC7), and suitable for light traffic. If AC10 is used the minimum compacted depth should be 30mm.

The compacted asphalt shall have a mean density of 94% of the laboratory compacted density (50 blow).

14. Schedule and Terms of Payment:

This contract is for a fixed price, lump sum. The following schedule is to be completed by either the owner or the contractor as agreed. Then unit rates shall only apply if a variation to the work is found to be necessary and is agreed by the owner and contractor, preferably before the work is carried out.

(a) Preparation and compaction of a free draining, even subgrade as specified and remove spoil

(b) Sterilisation of subgrade

(c) Subsurface drainage: excavate trench, supply and lay pipe as specified and backfill with screenings

(d) Crushed rock base course: supply grade and compact ........... .... mm compacted thickness as specified

(e) Asphalt surtacing: supply, place and compact ............... mm compacted thickness as specified

(f) Miscellaneous (to be detailed, e.g. edging)

15. Guarantee:

Quantity Rate Amount

The contractor guarantees the works under this contract for a period of ............ years. The guarantee covers the remedy of failures due to deficiencies in materials or workmanship provided as part of this contract.

The guarantee does not cover damage arising from excessive use by heavy vehicles, deep seated soil movements, damage resulting from saturation of the base/subgrade (unless subsurface drains were installed as part of the contract), fuel spills and other factors for which the driveway and surfacing was not designed.

Signed:

Owner: ... .. ............. .... ............... .. .. .......... .. ..... . Contractor: ... ......... ...................................................... .

Date: ....... .... ............. ... ... ...... .. ..... ........ ............ ... ......... ..... ....... ......... .... ............ ..... ... ................. .................. ........ .

DISCLAIMER:

Although the information contained in this guide is believed to be fundamentally correct the Australian Asphalt Pavement Association does not accept any contractual tortious or other form of liability for its contents or for any consequences arising from its use.

SPECIFICATION FOR SMALL ASPHALT WORKS

1. This specification is for the construction of:

.................................... .................. . (driveway, pathway, others?)

2. The owner is: ............ .............................. .

Address of works: ....................................... .. ........................... ........... .... .. ....... ...... ....... .. ......... ............ .. .. ....... ... .. .

Telephone number: .............. ....... ........................... .

3. The contractor is: ...................................... .

Address: ...... .

Telephone number: ............... ................ .. ..... ............... ... .. ............ ...... .......... ..... ... ............................... .......... .

4. Levels and Grade:

The contractor will provide pegs to establish the finished level of the pavement as dictated by the owner and to provide a basis for the accurate finishing of all the pavement layers, to level, thickness and location. The finished surface should be free drain ing.

5. Pavement Thickness:

On the prepared subgrade a crushed rock base course shall be placed, spread and compacted to a minimum thick-ness of ............. mm (100mm minimum).

On the prepared crushed rock base the asphalt surfacing shall be placed , spread and compacted to a minimum thickness of ... ........ .. mm (e.g. 25mm minimum).

6. Equipment, Materials and Labour:

The contractor shall provide all the necessary equipment, tools, materials and labour to complete the works in accordance with this specification.

7. Smoothness:

Surface smoothness may be measured by placing a 3-metre straight edge on the finished surface and measuring irregu larities at the centre of the straight edge. The following irregularities are tolerable on sections of uniform grade or slope.

(a) machine laid work: 7mm (b) hand laid work: 10mm

8. Materials and Manufacture:

The materials used in the construction of this pavement shall comply to the following Australian Standard Specifica­tions guides in their present revised form:

AS 2008 Residual bitumen for pavements AS 2150 Asphalt (hot mixed) Crushed Stone Association : A Guide to Quarry Products

9. Preparation of Subgrade:

The subgrade shall be graded to provide a free draining slope without depressions which may trap water and compacted to a minimum of 95% of maximum dry density (95% MOD) by AS test 1289 (standard compaction). Any soft spots shall be brought to the attention of the owner and shall be excavated and replaced with the best available spoil from on-site. If this proves to be inadequate, suitable material may be imported under conditions negotiated with the owner.

10. Subgrade Drainage:

In poorly drained areas which have clay or other moisture-susceptible subgrades, subsurface drainage may be required. The level of the subsurface drain should be a minimum 300mm below the subgrade level and provided with a free outlet to a stormwater drain or channel.

The subsurface drain may be either 80mm earthenware pipes with gaps suitably covered or 50mm slotted PVC pipe or other approved products on the market The trench shall be a minimum 150mm wide and shall be backfilled with one size screenings of nominal size between 14mm and 20mm to the top of the crushed rock base course.

11. Subgrade Sterilisation:

The subgrade soil shall be ster ilised if specified by the owner. Steril iser shall be applied at a rate specified by the manufacturer by a method which will ensure a total and uniform coverage of the specified area.

12. Preparation of Crushed Rock Base Course:

The crushed rock base course shall be supplied , spread, graded to level and compacted . Care shall be taken to ensure that the surface level is sufficiently accurate to ensure that the finishing asphalt surface is of the specified minimum thickness.

The minimum compacted density on the crushed rock base shall be 95% MOD by AS test 1289 (modified compaction) .

13. Asphalt Surfacing:

To be carried out in accordance with the recommendation of AS 2734 "Asphalt (Hot-Mixed)- Guide to Good Practice:·

Mix selection will be as suggested in AS 2734, generally a mix with a small nominal size and high bitumen content is preferable (AC5 or AC7) , and suitable for light traffic. If AC10 is used the minimum compacted depth should be 30mm.

The compacted asphalt shall have a mean density of 94% of the laboratory compacted density (50 blow).

14. Schedule and Terms of Payment:

This contract is for a fixed price, lump sum . The following schedule is to be completed by either the owner or the contractor as agreed. Then unit rates shall only apply if a variation to the work is found to be necessary and is agreed by the owner and contractor, preferably before the work is carried out.

(a) Preparation and compaction of a free draining, even subgrade as specified and remove spoil

(b) Sterilisation of subgrade

(c) Subsurface drainage: excavate trench , supply and lay pipe as specified and backfill with screenings

(d) Crushed rock base course: supply grade and compact ............... mm compacted thickness as specified

(e) Asphalt surfacing : supply, place and compact ............... mm compacted thickness as specified

(f) Miscellaneous (to be detailed , e.g. edging)

15. Guarantee:

Quantity Rate Amount

The contractor guarantees the works under this contract for a period of .. ..... .... . years. The guarantee covers the remedy of failures due to deficiencies in materials or workmanship provided as part of this contract.

The guarantee does not cover damage arising from excessive use by heavy vehicles, deep seated soil movements, damage resulting from saturation of the base/subgrade (unless subsurface drains were installed as part of the contract) , fuel spills and other factors for which the driveway and surfacing was not designed .

Signed:

Owner: .. .......... ....... .... ... .... ...... .. ... .. .... ..... .. ... .. .... . . Contractor: .... ............ ..

Date: .. ... .. ..... ... ........... .... .. ... .. .. ... ... .... .... .. ..... .. .. ........ .... ...... .. .. ......... ......... .. .. .. ... .

DISCLAIMER:

Although the information contained in this guide is believed to be fundamentally correct the Australian Asphalt Pavement Association does not accept any contractual tortious or other form of liability for its contents or for any consequences arising from its use.

The Information Booklet series is an ongoing one, providing infor­mation on various aspects of asphalt, such as its applications, terminology, constituent materials, manufacture, placing and sub­sequent recovery, recycling, domestic uses and spray sealing.

To date the following Information Booklets have been produced and are available from AAPA.

IB-1 ASPHALT BASICS IB-2 RECOMMENDED TERMS FOR THE AUSTRALIAN

ASPHALT INDUSTRY IB-3 ASPHALT APPLICATIONS IB-4 ASPHALT CONSTITUENTS IB-5 ASPHALT PRODUCTION AND PLACING IB-6 ASPHALT RECYCLING IB-7 ASPHALT DRIVEWAYS, TENNIS COURTS &

COLOURED ASPHALT IB-8 SPRAYED SEAL BASICS

The Australian Asphalt Pavement Association was formed in 1969 as a non-profit organisation to promote the economic use of asphalt based on sound technical and commercial grounds.

Throughout its history, AAPA has maintained as its major objective the dissemination of technical knowledge aimed at constant updating and improvement in asphalt technology.

AAPA Members include manufacturers of asphalt and other bitumen bound products, State Road Authorities, Local Government, paving consultants, material suppliers, plant and machinery manufacturers, paving and sealing contractors and individuals interested in asphalt technology.

ISSN 0817-9832 ISBN 0 646 18841 0

australian asphalt pavement association

Head Office:

First Floor 21 Burwood Road Hawthorn Victoria 3122

Tel : (03) 819 4999 Fax : (03) 819 5278

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