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Matched Legal Cases: ['art226', 'art 226', 'ART 226', 'art 226', 'art 225', 'art 275', 'art 215', 'art 215', 'art 226', 'art 120', 'art 226', 'art 221', 'art 150', 'art 226', 'art 226', 'art 285', 'art 275', 'art 225', 'art 215', 'art 226', 'art 140', 'art 215', 'art 215', 'art 215', 'art 215', 'art 215', 'art 215', 'art 275', 'art 275', 'art 275', 'art 275', 'art 275', 'art 275', 'art 226', 'art 225', 'art 225', 'art 226', 'art 226', 'art 226', 'art.\n4', 'art226']

Part226 Guidelines by VzPbbBK9
122698118
VzPbbBK9
Edition: March 2009                                                                                                                                                           Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
TECHNICAL COMMENTARY ON PART 226
APPLICATION OF SPRAYED BITUMINOUS SURFACING
SPECIFICATION                                                                                                                             COMMENTARY
1.        General
2.        Quality Requirements
3.        Materials
4.        Constraints to Work
5.        Protection of Road Fixtures
6.        Cleaning of Pavement
7.        Operation of Sprayer
8.        Application of Prime and Primerseal
9.        Application of Binder
10.       Application of Strain Alleviating Membrane Interlayer
11.       Application of Aggregate
12.       Removal of Loose Aggregate after Rolling
13.       Paving Fabric
14.       Surplus and Waste Material
15.       Records of Work
16.       Application Tolerances
17.       Test Procedures
18.       Hold Points
19.       Verification Requirements and Records
20.       Measurement and Payment
Appendix 1         Volume Conversion Table - Bitumen Emulsion
Appendix 2         Volume Conversion Table - Hot Bituminous Based Binders
Appendix 3         Approved Bitumen Adhesion Additives
Appendix 4         Seal Coat Treatment - Daily Record Sheet
Appendix 5         Guidelines for Addition of Cutter
This Part specifies the requirements for the application of sprayed bituminous surfacing or resurfacing (sprayed seal coat treatment).
Documents referenced in this Part are listed below:
AS 1141            Methods for Sampling and Testing Aggregates
AS 1289            Methods of Testing Soils for Engineering Purposes
AS 2008            Residual Bitumen for Pavements
AS 3706            Geotextiles – Methods of Test
The Contractor shall prepare and implement a Quality Plan that includes detailed procedures and documentation for:
Primer, Primer Binder, Binder and Overspray
(a) Achievement of flux and/or cutter proportions.
(b) Achievement of a homogeneous mixture (including the elimination of tank contamination).
Adherence to (c) should be audited
(c) Transportation of Polymer Modified Binder in accordance with &quot;Code of Practice: Manufacture, Storage and Handling of
Polymer Modified Binders, First Edition&quot;, Australian Asphalt Pavement Association, June 2004, Clause 4.2.1 and Clause 4.2.6.
Edition: March 2009                                                                                                                                                              Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
(d) Control of temperature.
(f) Details of spray bars proposed and methods to avoid blockage of nozzles and valves (refer Clause 226.7 &quot;Operation of Sprayer&quot;).
(g) Ensuring adequate cure of the primer/overspray.
(h) Field sampling of binder.
In addition to the above, for Emulsions, Polymer Modified Binders and Crumb Rubber
Want crumb rubber to be well blended, not segregated. Crumb rubber and High Bitumen Content Emulsions should actually be sprayed
(a) Management of curing process for emulsion, including traffic management for emulsions (refer Clause 226.4.1”Constraints to          using B6 nozzles
Work”)                                                                                                                              Management of storage times and temperatures is important for emulsions, PMBs &amp; Crumb Rubber
(b) The manufacturer&#39;s recommendations regarding: handling instructions including temperature range, maximum storage time for
particular temperatures, maximum heating temperature, and any other relevant information
(c) For crumb rubber binder and high bitumen content emulsions the achievement of a homogeneous product that can be sprayed as a
uniform application of binder across the pavement, free of streaking. Details that shall be included as a minimum are
recommended spray nozzle sizes, maximum width of spray runs, and management of storage times &amp; temperatures.
(d) Materials Technical Data sheets for each product.
(a) Controlling loading to avoid contamination and wastage
(b) Removal of dust and dirt
(c) Application of precoat
(d) Application of aggregate
(e) Rolling of aggregate.
If not part of the Post Tender Submission, the procedures shall be submitted at least 28 days prior to the commencement of site work.
Provision of the procedures listed in this Clause shall constitute a hold point.
3.1       Quality of Materials
Binder (including Prime, Primer Binder, C170, C320, PMB, Crumb Rubber, Multigrade and Emulsion), Flux and Cutter shall comply with
Part 225 &quot;Supply of Bituminous Materials&quot;.
Paving Fabric shall comply with Part 275 &quot;Supply of Geotextiles&quot;.
Aggregate shall comply with Part 215 &quot;Supply of Pavement Materials&quot;.
Where aggregate is supplied by the Contractor:
Prior to the use of sealing aggregates, a HOLD POINT shall apply for the purpose of ensuring that test certificates have prepared   ALD test results must be provided. A moisture content test certificate may be requested if doubts about the dryness of the aggregate can
and that the moisture content is in accordance with Clause 4.3 &quot;Aggregate&quot;.                                                         not be resolved by the supervisors on site
Prior to the commencement of sprayed bituminous surfacing, the Contractor shall demonstrate (by the submission of positive test     This should be enforced before the sprayer arrives at any particular job. We are finding now that requirements for adhesion agents for
results) the precoating system required to ensure compliance with the aggregate stripping requirements as determined by TP 705      stone from particular quarries are varying from face to face and from time to time; TSD is also using different binders to the past..
for the proposed aggregates.
At least 7 days prior to the commencement of sprayed bituminous surfacing, the Contractor shall supply a NATA endorsed test         Average least dimension (ALD) and traffic (AADT) are the two most important inputs to a successful seal design. Where the contractor
certificate for the Average Least Dimension of all sealing aggregates. Aggregates used in the determination of the Average Least    supplies aggregate, but the bitumen application rate is provided by DPTI, then this application rate is based on a complete guess. In order
Dimension shall be sampled in accordance with TP 226 and the Average Least Dimension shall be determined in accordance with         to reduce stripping and bleeding of new work, it is important that the nominal design is replaced with an actual design, which requires
Part 215 “Pavement Materials”                                                                                                       actual ALD. This is particularly critical in designs under high traffic, such as overtaking lanes.
Edition: March 2009                                                                                                                                                            Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
Where aggregate is supplied by the Principal:
Prior to the use of sealing aggregates a HOLD POINT shall apply for the purpose of ensuring that the quantity of stockpiled        A moisture content test certificate may be requested if doubts about the dryness of the aggregate can not be resolved by the supervisors on
material is agreed and that the moisture content is in accordance with Clause 4.3 &quot;Aggregate&quot;.                                     site
At least 7 days prior to the commencement of sprayed bituminous surfacing, the Contractor may, upon request be supplied with
test results for the Average Least Dimension of all sealing aggregates.
3.2      Measurement of Materials
Unless otherwise stated all rates and quantities under this Specification relating to Prime, Primer Binder, C170, C320, PMB, Crumb
Rubber, Multigrade, Emulsion and cutter shall refer to measurement by volume at 15oC.
Where the volume of such materials is measured at a higher temperature, the Volume Conversion Formulae shall be used for converting
the volume to equivalent volume at 15oC. The Volume Conversion Tables are included as Appendix 1 and Appendix 2. For the purpose
of sprayed bituminous surfacing, rates and quantities relating to volume of aggregate shall refer to loose volume.
4.       CONSTRAINTS TO WORK
4.1      Binder and Traffic
The Contractor shall comply with the constraints regarding binder listed in Table 4.1 Refer to Part 120 &quot;Provision for Traffic&quot; for other
constraints relating to traffic control.
Treatment                                                     Constraint
The word “traffic” here refers to construction light-vehicles only. Public and commercial traffic let loose on a prime will damage the
Prime                    Traffic shall not be permitted on the surface within 24 hours of spraying or until the prime                      surface within hours.
has dried sufficiently so as not to be damaged by vehicles.                                                       Cutback primes contain a large amount of volatiles. If these become trapped under a new seal, the seal could be expected to bleed during
the next bout of warm weather. The “72 hours” is a consensus between industry and DPTI. Obviously, the longer this is left, the better the
A binder shall not be applied over a cutback prime within 72 hours of spraying of the prime,                      long term outcome.
or in cold weather until the solvent cutters have substantially evaporated.
Cutback primer binders also contain a large amount of volatiles. If these become trapped under a new seal, the seal could be expected to
Primer binder            A binder shall not be applied over a cutback Primerseal within 6 months of spraying of the                        bleed during the next bout of warm weather. Previous specifications required “14 days” however experience demonstrated this was not
Primerseal.                                                                                                       sufficient. “28 days” is a consensus between industry and DPTI. Obviously, the longer this is left, the better the long term outcome
Crumb Rubber             Crumb Rubber shall not be stored longer than 12 hours unless sufficient evidence is                               South Australian experience with crumb rubber is still quite young. Until work practices and results provide evidence to the contrary,
provided that demonstrates the ability of the storage/blending vessel to maintain the                             DPTI want blending on site. The definition of “site” is the site where the stockpiles or the bulkers are.
consistency of the binder. In that case, an additional 12 hours of storage will be allowed
provided that the temperature of the binder is held between 140oC and 150oC.
Plant blended crumb rubber may only be transported for one hour from the point of
manufacture, and both plant blended and field blended crumb rubber must be sprayed within
four hours from the transfer into the sprayer.
Base binder shall consist of C170 bitumen complying with AS 2008
Once rubber has been added to the base binder the contents shall be circulated for the
minimum period indicated in the quality plan to provide a homogenous product of consistent
Emulsion                 In addition to the protective measures specified in the Quality Plan, the Contractor may be                       Emulsion seals are very tender during their early life, and are easily damaged by high-speed traffic. If a still “cheesy” resurfaced lane
required to provide pilot vehicles to control traffic speeds to 25 km/h for at least 2 hours or                   must be opened to traffic to allow work on an adjoining lane to commence, then stop-go traffic control to permit traffic from one direction
until the binder has cured sufficiently to retain the screenings.                                                 at a time will also need to be accompanied by a pilot vehicle to lead the platoons through at controlled, slow, speeds.
This clause also means that the last emulsion run of the day may need to be completed early enough to allow at least two hours of daylight
All two-coat seals       Both courses of a double seal shall be laid on the same day.                                                      and active on-site traffic control to continue.
Edition: March 2009                                                                                                                                                                 Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
The application rate of the first coat of a two coat seal is much lower than a single seal design for the same size stone. Thus if the first coat
The top seal shall overlap each finished edge of the bottom seal by 50 mm.
of a two coat seal was left open to traffic overnight, it could be expected to severely strip.
4.2      Aggregate
The traditional rule of thumb used to be: ‘Pick up a handful of damp aggregate in one hand, toss the aggregate back, wipe the palm of the
Hot binders shall not be sprayed if the moisture content of the screenings exceeds 0.8% for non-PMB’s or 0.1% for PMB&#39;s as determined          damp hand over the back of your other hand. If the back of your other hand also becomes damp, then the aggregate is too wet to use’.
in accordance with AS 1289.2.1.1 and AS 1289.2.1.4.                                                                                            This test was then tempered with accumulated local knowledge of how aggregates from different quarries behaved when spread damp. All
of this became too hard to word in a specification, so the resulting clause was an attempt to scientifically come to a similar conclusion.
4.3      Temperature, Wind and Weather
Common sense on site usually means agreement can be made on site without laboratory moisture testing, however this clause would be
The acceptable limits for temperature, wind and pavement condition prior to sealing are detailed in Table 4.3.                                 enforced should site resolution not occur.
Pavement temperatures shall be measured in the shade.
Wind speed shall be measured using a wind speed gauge.
Always measure pavement temperatures in the shade, as it is the weakest link, and where stripping will always first commence.
With modern infra red thermometers, the pavement temperature is simply measured where the pavement is in the shade. If there is no
Minimum                Maximum              Maximum                                                               natural shade over the job, measure the pavement temperature in your shadow. This ensures that the infrared thermometer measures the
Product            Air/Pavement           Air/Pavement          Wind Speed                Pavement                                    heat of the pavement and not reflected heat from the sun.
Temperatures (oC)      Temperatures (oC)         (KPH)
These maximum wind speeds are DPTI’s current best guess, and further observation and comment on this is needed. A maximum wind
Prime                    10/10                  None                   20                Dry
speed is basically to allow for the wind chill factor, but in addition if it is too windy the fan of bitumen from each jet will be distorted,
Primer Binder            10/10                  None                   30                No free water present                                resulting in an uneven application rate. This then leads to patchy stripping and bleeding.
C170                     15/15                  None                   30                Dry                                                  A sprayer run shall not commence if it appears likely that either temperature will fall below 15 oC before completion of all work for that
C320                     20/20                  None                   30                Dry                                                  run, including rolling time.
PMB (SBS based)          20/20                  None                   30                Dry                                                  This is particularly important in spring and autumn. When there is not enough residual heat in the pavement, the binder becomes brittle
PMB (PBD based)          15/15                  None                   30                Dry                                                  before the aggregate has finished reorientating, and aggregate snaps off resulting in brittle-failure stripping.
Crumb Rubber             17/20                  None                   30                Dry                                                  The Pavement may be damp, but not wet enough to allow runoff of the emulsion into the side drains. Similarly, emulsions should not be
Multigrade               15/15                  None                   30                Dry                                                  sprayed when rainfall sufficient to cause runoff is expected that afternoon or overnight.
Emulsion                 5/5                    40/70                  30                No free water present                                A cutback overspray is sprayed at a higher temperature than a cutback reseal. The binder needs extra viscosity so it can flow down around
Note 1: 15/15 can be applied for SAMI in non-trafficked areas                                                                                  the shoulders of the “hungry” aggregate beneath it, and fulfil its purpose of sticking the hungry aggregate in place to prevent stripping
Air temperatures shall be measured using a thermocouple based temperature device taken 1 metre from the pavement surface. The
temperature device shall be positioned:
(a) away from any heat source;
(b) shaded from the sun; and
(c) not protected from the wind.
Until notified otherwise, the only Polymer Modified Binders (PMB) that are PolyButaDiene (PBD) based are Mobil and BP formulations
of S35E.
5.       PROTECTION OF ROAD FIXTURES
The Contractor shall prevent primer, binder, aggregate or other material used on the work from entering or adhering to gratings, hydrants      Generally achieved in practice by careful placement of heavy duty paper and/or shovel loads of aggregate.
or valve boxes, inspection pit covers, kerbs and other road fixtures. Damage to roadside furniture to be recorded on the daily record sheets
to enable costs to be recovered.
6.       CLEANING OF PAVEMENT
When priming a base course it is also accepted practice to slightly dampen the surface, with a very quick pass of a water truck. This
The pavement shall be cleaned free of loose material so that primer will be absorbed into the base, or binder adhere to the existing seal,      prevents the prime from prilling around surface dust particles, when it should be soaking into the top few millimetres of basecourse.
without prilling or being absorbed onto loose material.
The method of cleaning shall ensure that damage to the existing surface is prevented. Steel brooms shall not be used on unsealed base.          Steel bristle brooms can be used for cleaning an existing seal prior to a reseal, but not for cleaning bare basecourse.
The Contractor shall remove all raised pavement markers and pavement bars prior to sealing and undertake any necessary repair to the existing   Removed pavement markers are not to be disposed of within the road reserve.
seal. Additional payment will not be made for this activity.
7.       OPERATION OF SPRAYER
The application of primer, primer binder, overspray and binder shall be by means of sprayer(s) currently certified as complying with            A copy of the current Sprayer certification certificate for each sprayer should be kept in the sprayer cabin and sighted prior to the first run
Austroads Sprayer Calibration Procedures series AGPT/T530 to AGPT/T535. Hand spraying will only be permitted when the use of a                  of every contract, and again for every replacement sprayer. DPTI no longer issues sprayer certificates, they are issued by an independent
mechanical sprayer is not practicable. All sections of road 8 m or less in width and with the same application rate shall be sprayed in one     but NATA Certified service provider. A list of currently Certified sprayers in Australia is maintained on the AAPA web site
pass. Where the width of the run is greater than the maximum width that the sprayer is calibrated to spray, the Contractor shall include        http:/www.aapa.asn.au
details of how a uniform application of binder across the joint will be achieved in the Quality Plan.                                           Hand spraying is notoriously un-accurate, usually resulting in far too-heavy an application rate. Its use should be minimised to where
wheel paths will not generally travel, such as painted islands and safety-bar layouts.
Bitumen impregnated paper shall be used at the start and end of each run to produce a straight line with not gaps or overlap between            When a road is sprayed in two half widths, a cold joint occurs at the middle, and this is prone to stripping.
adjacent runs.                                                                                                                                  On steep grades where we specify different application rates for uphill and downhill, and the road must be sprayed in two half widths, to
prevent wheel path bleeding and stripping. The trade off here is that we then accept that stripping along the cold joint could occur. The
use of an end jet would reduce the fanning out of resultant cold bitumen on the pavement.
Where binder application rates below0.7 litres per square metre are specified, A3 nozzles or S2 (Austroads AN9) nozzles shall be used.          The minimum of 0.8 L/m2 was reduced to 0.7 L/m2 in 2005 to reflect achievable field practice.
The most commonly used nozzle size is A4 (Austroads AN 18) To spray an application rate lower than 0.7 L/m2, the forward speed
required is faster than the sprayer can travel. This problem is overcome by fitting small nozzles with half the rated output (L/min).
Check beforehand that the sprayer has been calibrated for A3 or S2 nozzles, in addition to A4. This will be detailed on the Sprayers
calibration certificate, carried in the sprayers Cabin.
Information on the change-over of Sprayer Nozzles from the Copley numbering system to the Austroads Designation is found at APRG
Pavement Work tip No.33 “Sprayed Seals – Selection of Spraying nozzles” issued June 2002, which can be downloaded for free at
http://www.aapa.asn.au/docs/publications_worktips.html
8.       APPLICATION OF PRIME AND PRIMERSEAL                                                                                                    Note that precoating of aggregate for primerseals, is not required. There are already sufficient precoating type agents in the primerbinder.
Prior to the application of the prime or primerseal, a HOLD POINT shall apply. Release of the hold point will occur when it has been            Before placing primes and primerseals, don’t forget moisture content and the ball penetration test. Refer to Part 221
(a) the surface to be primed or primersealed is suitable,
(b) marked guide lines have been set out correctly; and
(c) the Contractor is properly prepared to proceed.
This refers to the top 20mm of base course, whereas the 70% OMC referred to above refers to the full basecourse depth.
For unstabilised granular pavements, priming and/or primer sealing shall not be commenced until the moisture content of the top 20 mm of
the base is less than 60% of OMC.
Where slow absorption of the prime causes interference with traffic or the application of binder, or at an intersection where traffic must
This clause is based on private cars entering their residential addresses. Approved cover material may be crusher dust or washed
cross the new prime, the Contractor shall apply approved cover material evenly over the primed surface.
concreting sand. The 1983 spec advised that any such cover shall not be applied until two hours after the application of the primer
The Contractor shall maintain the surface in a satisfactory condition until the seal coat is applied.
9.       APPLICATION OF BINDER
Prior to the application of binder a HOLD POINT shall apply. Release of the hold point will occur once it has been verified that the            Check there are enough aggregate truckloads to continuously cover the binder before it cools, and there are enough roadworthy rollers
pavement surface is suitable for the application of binder and that the Contractor is properly prepared to proceed.                             ready to cover the full width in one pass.
A list of approved bitumen adhesion additives is included as Appendix 3. The adhesion agent will only be considered to be active for a          Appendix 3 is updated from time to time at the request and cost of the adhesion agent suppliers. We believe the active ingredient in most
period of 10 hours after inclusion into the binder.                                                                                             adhesion additives only remains active for about 10 hours after it has been added to bitumen
Class 170 bitumen in a sprayer shall be deemed to be 100:0:0 and a tolerance of + 0.5 parts of cutter shall be allowed for the effect of        “100:0:0” describes the ratios, per 100 parts bitumen, for
minor quantities in previous loads, cleaning and the like.                                                                                      C170 bitumen : Flux (Industrial Diesel Fuel) : Cutter (Power Kerosene)
This format is traditional, but Flux is never called for by DPTI
Where cutter and/or additives are required to be included in the binder, these shall be added at the site of the works. Cutter shall be added   “100:0:0:0” describes the ratios, per 100 parts bitumen, for
in accordance with Appendix 5. Flux shall not be used unless approved otherwise.                                                                C170: Flux (IDF) : Cutter (PK) : Approved Adhesion Agent
There is no guarantee that cutter or Adhesion Agent added at Adelaide, are still active or present within the binder by the time it reaches a
rural site.
Carry over of cutter and adhesion additive content, for spray load calculations, shall not be permitted after overnight storage.                Overnight storage at warm storage temperatures may drive off the volatile cutter, and neutralise the Adhesion Agent. Their effectiveness
by the next day can be ignored.
The application temperatures for primes, primerbinder and binders shall comply with Table 9.
Minimum Spraying          Max Re-heating         Minimum Spraying           Max Re-heating                             Refer AAPA Advisory Note 7 “Guide to heating and storage of binders for sprayed sealing and hotmix asphalt”. This advisory note was
Product              Temp (oC)               Temp (oC)                Temp (oC)                Temp (oC)                                updated in August 2003, and is now included as a centre spread in the June 2004 first edition AAPA document “Code of Practice:
Un-cut                  Un-cut                    Cut                       Cut                                   Manufacture, storage and Handling of Polymer Modified binders”, which can be downloaded as a free .pdf from www.aapa.asn.au
Light Prime                      15                       30                       na                      na
Medium Prime                     40                       60                       na                      na
Primer Binder                    95                      120                       na                      na
C170                             175                     185                   Resultant                   185                                 185oC max. for C170 has been specified for at least the last 20 years, and is still specified by most Australian Jurisdictions and by AAPA.
C320                             175                     185                   Resultant                   185
PMBs are generally more viscous (thicker) and need to be heated to a higher temperature to enable them to thin and fan properly out of the
PMB                              190                     200                      185                      190                                 sprayers nozzles. We specify 195oC max. AAPA advisory note 7, Note 1, says that PMB temperatures at point of spraying must not
exceed 200oC. If they can’t exceed this for the short time they are in the sprayer, then I consider they cant exceed this for the longer times
Crumb Rubber                     190                     200                      190                      200                                 that they are in the Bulker and in storage.
Multigrade                       175                     185                   Resultant                   185
It is acknowledged world wide that SBS binders double their degradation rate for every 10 oC rise in temperature. Therefore, any PMB
Emulsion                   Manufacturers                  90                       na                      na                                  bulker arriving on site at above 195oC should be rejected.
If the job is rained out and binder must be stored for a day or more, then lower temperatures, for medium term storage, are quoted in
*For cut C170, C320 and Multigrade the binder shall be heated to 185oC, additive and/or cutter added and then sprayed at the resultant          AAPA advisory note 7. Theses should be adhered to.
temperature.                                                                                                                                    C170(PMB) is regarded as the most widely used bituminous binder for sprayed sealing in South Australia for those works other that
shoulder sealing where C170 predominates
The use of alternative products to those nominated in the Quality Plan for binder and precoat shall be subject to approval and the
Contractor demonstrating the suitability and compatibility of the products.
This explains what “resultant” means in Table 9
10.      APPLICATION OF STRAIN ALLEVIATING MEMBRANE INTERLAYER
A SAMI seal shall be left exposed for at least 1 day but no more than 7 days, prior to the application of the asphalt overlay. If the SAMI      SAMIs are left exposed to the air to let any volatiles in them evaporate, rather than soften-up the asphalt that will be placed over them.
seal is subject to traffic, other than construction vehicles, then an alternative time for the application of the asphalt overlay may be
directed.                                                                                                                                       SAMIs are designed for max membrane thickness, rather than carrying heavy traffic loads (which is what the asphalt is for), so that they
need to be covered before the traffic has orientated the aggregate to the point were the SAMIs start to bleed.
If the weather is hot, amount of volatiles are low, and traffic is heavy, the Superintendent may elect to relax the one-day minimum.
Where the temperature of the pavement surface on which the SAMI is to be placed is below 20 oC, the following additional requirements           Often asphalt work occurs outside the spray-sealing season, and minimum temperatures cannot be met.
If the SAMI is not to be trafficked until after the AC has been placed, the Superintendent could relax the minimum temperature, as the
(a) The use of an emulsion binder, or
potential for stripping, with its associated public safety hazards, does not exist.
(b) The use of hot application of binder with hot sealing aggregate.
SAMI binders may be purchased in Emulsion equivalents (currently sourced from interstate), in which case the minimum pavement &amp; air
temps come down to 50C (Table 4.3). However, when trafficking be aware of Constraints to Work (clause 4.1).
Another solution may be to heat the aggregate through an asphalt plant and deliver to site, spread and roll whilst still hot. This will reduce
the potential for stripping, and has been successfully done.
11.      APPLICATION OF AGGREGATE
11.1     Precoating
Precoat may be applied at the quarry or at the stack site. Precoat shall be applied such that at least 80% of each stone’s surface is coated.   Check that the precoater is distributing precoat evenly across the width of the conveyor belt.
A vibrating screen aggregate loader shall be used where aggregate is precoated at the stack site.                                               A vibrating screen aggregate loader (shaker deck) is specified because it removes both fines (dust) and oversize (stockpile floor rubble) in
addition to giving better precoating coverage.
Precoat shall consist of not less than 30 parts of bitumen to 100 parts of IDF and 1.5 parts approved adhesion agent.
Precoated aggregate may be stockpiled, provided that the Contractor implements approved measures to ensure that contamination does not
Aggregate shall be used within 1 month of precoating.
The methods to eliminate contamination from deleterious material and deterioration of the pre-coated aggregate shall be included in the         If precoating-in-advance is allowed, ask for this Quality Plan and read it
The Contractor’s methods to monitor, manage, mitigate or eliminate pollution or environmental impacts of pre-coated aggregate sites will
be included in the Contractor’s Environment Management Implementation Plan outlined in Part 150 &quot;Environmental Management
Requirements&quot;.
11.2     Aggregate Spreading and Rolling
Minimum                                                                               In 1990 the basic “T” formula was empirically modified by the then Asphalt Engineer to allow for PMBs by introducing a 1.5T and 2T
Product                                      Passes over Full                    Rolling Time                                        factor. The addition of cutter to PMBs was not allowed at that time, due to the PMBs then available
Primerseal                               5                    4            T
C170                                     5                    4            T
pave temps &lt; 25oC: 2T
C320                                     3                    6
25oC &lt; pave temps &lt; 30oC: 1.5T
Edition: March 2009                                                                                                                                                                   Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
pave temps &gt; 30oC: T
PMB (SBS based)                          3                     6           25oC &lt; pave temps &lt; 30oC: 1.5T
PMB (PDB based)                          5                     4           T
Crumb Rubber                             3                     6           25oC &lt; pave temps &lt; 30oC: 1.5T
Multigrade                               5                     4           T
Manufacturer’s                           T
Emulsion                                                       4
The binder shall be covered with aggregate as soon as practicable. In no case shall this exceed the times given in Table 11.2.                    The most effective time to apply the aggregate is while the binder is still hot, and “aggregate wetting” of the binder occurs. It takes only a
couple of minutes for the hot binder to revert to the temperature of the pavement beneath it. As PMBs are more viscous (thicker), they
need a higher temperature to soften them up and for aggregate wetting to occur - hence they need to be covered in a quicker time. Some
PMBs also form a surface “skin” on cooling, which the aggregate does not penetrate – again, they need to be covered quickly before this
The aggregate covered surface shall be rolled with a minimum contact pressure of 690 kPa over the whole surface.                                  Again, the most effective time to apply the aggregate is while the binder is still hot, and “aggregate wetting” of the binder occur
Rolling shall commence immediately after aggregate spreading has commenced.
Notwithstanding the requirements of this Clause, the minimum number of passes over the full width treated shall be made as per                    The unmodified component was specified in 1983, the modified component circa the 1990/91 season. The importance of these minimum
Table 11.2 for all pavement temperatures. Rolling shall continue without interruption until the aggregate is firmly embedded in the binder.       passes were confirmed in some 1996 R&amp;D published as: Neaylon, KL, “The Measurement of Aggregate Reorientation in Sprayed Seals
using Stereoscopic Microphotogrametery”, Roads 96: Joint 18 th ARRB Transport Research Conference and Transit New Zealand
Transport Symposium, Christchurch, NZ, September 1996.
For all binders there shall be sufficient rollers to cover the full width to be sealed with one pass. Roller speeds shall not exceed 5 km/h for   This requirement was added, initially for PMBs only, circa ‘90/91 season. Subsequent R&amp;D work in 1996 (quoted above) saw this
the first 2 passes and 15 km/h thereafter.                                                                                                        extended to all binders.
The rolling time shall be calculated in accordance with Table 11.2 and the requirement below.                                                     This is the original Highways Department of SA rolling formula that has grown over time from proven practice. The original rule of
thumb was 90 minutes of rolling per sprayer run (about 1,000 gallons) per each 11 tyred 11-ton roller. On one particular job, due to a
A base rolling time per 4 000 litres of binder sprayed shall be calculated by the formula:                                                        mechanical breakdown a 7-ton roller was pressed into service and a site agreement reached to factor up rolling time by 11/7 accordingly.
This was later formalised into a rolling formula that could cater any size rollers. The basic formula devised was further soft converted to
metric, and is currently specified as T=216/W.
W                                                                                                                         In 1996 rolling practices in SA, Vic, NSW, Qld, and NZ were all different. In an attempt to harmonize practices, the Austroads Pavement
Reference Group in 2000 published Pavement Work tip No. 24 “Sprayed sealing – Rolling of Cover Aggregate”, which can be
Where T is the time in minutes and W is the total width covered by the rollers in metres.                                                         downloaded for free from http://www.aapa.asn.au/docs/publications_worktips.html . DPTI trialled this new method, but concluded that
although we had confidence in the reduced rolling that this afforded in warm temperatures, concerns still existed over lowering the amount
of rolling in cooler temperatures and in lower traffic levels. Austroads Work Tip 24 method was adopted briefly in this specification only
for Pavement temperatures of 300C and over. It has since been removed due to lack of DPTI &amp; Industry interest/use. It could be
reconsidered upon specific company request
Edition: March 2009                                                                                                                                                               Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
12.      REMOVAL OF LOOSE AGGREGATE AFTER ROLLING
When the binder has hardened to a stage at which no more aggregate can be pushed into it by rolling, or by traffic moving at slow speeds,
all loose aggregate shall be removed 900 mm clear of the edge of the seal. Loose aggregate only shall be removed, and without
disturbance of the embedded aggregate.
The above shall apply to all seals, including the first coat of a double seal.
Where the pavement has kerb and gutter, the loose aggregate shall be picked up and removed from the site. Removal of loose aggregate
shall commence within 12 hours of the completion of rolling.
Prior to removal of loose aggregate after rolling, a HOLD POINT shall apply for the purpose of ensuring the binder has properly adhered
to the aggregate and pavement. Release of the hold point will occur once it has been verified that the removal of loose aggregate will not
damage or have the potential to damage the new seal through the loss of aggregate and loose aggregate does not present a traffic hazard.
13.      PAVING FABRIC
Where the use of paving fabric is specified, it shall comply with Part 285 &quot;Supply of Geotextiles&quot; and shall be placed in accordance with     Important practical guidelines that will be of assistance to field personnel are: Materials Technology Section Technical Note No. 22
the manufacturer&#39;s instructions and the following:                                                                                            “Geotextile Reinforced Sprayed Seals”, issued Dec 2000, available from the Supervising Surfacings Engineer; and APRG Pavement
Worktip No 25 “Geotextile Reinforced Sprayed Seals”, April 2001, available for free download from
(a) Public traffic shall not be permitted to travel on the paving fabric until the first layer of the specified seal has been applied;
Never use wet or damp Geofabric, as it will not absorb bitumen to the required amount.
Paving fabric in South Australia is laid from a framework attached to either a Tractor or Front-End-Loader (Not a Multi tyred roller as is
the case in some Eastern States.) Particularly if the FEL has hydraulic steering, the placement of the roll often varies laterally by a large
amount. In order to ensure that full width crack retention and waterproofing is achieved, a minimum overlap was specified. The intent is
to ensure that at the worst 5% of the join, at least a but joint is achieved. The specified overlap was reduced in 2002/03 to reflect
improving work practices.
It is common for Geofabric seals to strip over the overlap, especially where the contractor has no procedure to allow for the doubling of
binder absorption into fabric at these locations. It is therefore important that the overlap does not occur in a wheel path. It would be better
if the contractor had a procedure to allow for the doubling of binder absorption into fabric at these locations.
The extra 100mm width, gives the laying front-end-loader a bit of room to wander without affecting the reseal integrity. If end-jets are not
(b) Overlap of the paving fabric shall be between 100 and 150 mm;                                                                             used, the overlap must be 250mm
(c) Paving fabric shall be placed so that the transverse joint between adjacent rolls shall overlap in the direction of traffic;
(d) Longitudinal overlap of the fabric shall be placed within 200 mm of the centreline or lane line;                                          This is now believed to be more temperature related than equipment related, but when too much tack coat works to the surface, the fabric
sticks to the tyres of passing equipment that then lifts the fabric and tries to tear or stretch it.
(e) The fabric shall be bonded to the pavement with a tack coat sprayed 100 mm wider than the fabric. Appropriate end jets shall be           This clause is based on experience that has been found to work.
used to ensure the specified tack coat rate is applied across the entire width of fabric;
(f) Equipment used to place fabric shall not cause undue migration of the underlying tack coat into the fabric; and
(g) Upon completion of placing of fabric and prior to application of binder, the fabric shall be rolled with 4 passes of a pneumatic multi-
wheel roller.
A certificate of compliance for the paving fabric shall be included with the respective AE Lot data.                                          Refer Table 19. In general, the Certificate must be to Australian Standards and issued by a NATA endorsed laboratory. Refer Clause 6
Test Procedures of Part 275 “Supply of Geotextiles”
Seal dimensions specified do not allow for additional binder or fabric required for overlap.
14.      SURPLUS AND WASTE MATERIALS
Waste, including unused contractor supplied aggregate, bitumen, empty containers or other materials remaining after completion of the         Includes removed Raised Pavement Markers
work shall be removed from the site by the Contractor and the work site shall be left in a neat and tidy condition. Disposal shall be in
accordance with the Environment Protection Act.
All work shall be conducted in accordance with the DPTI Environmental Code of Practice.
15.      RECORDS OF WORK
The Contractor shall complete the form DPTI 397 &quot;Seal Coat Treatment - Daily Record Sheet&quot;, included as Appendix 4, or an approved
equivalent, which shall then be certified correct by the Contractor and forwarded by the start of the next working day. Details of all
materials applied shall be recorded immediately after each spraying &quot;run&quot;.
The Contractor may submit an alternative recording form for acceptance provided that all details required in form DPTI 397 are included.
Note that the Contractor is required to submit documentation in accordance with Part 225 &quot;Supply of Bituminous Materials&quot; and Part 215
&quot;Supply of Pavement Materials&quot; to demonstrate compliance with the Specification.
The Contractor shall complete the form DPTI 397 &quot;Seal Coat Treatment - Daily Record Sheet&quot;, included as Appendix 4, or an approved            There is a problem Nationally with the introduction of point-of-delivery specifications for PMBs, as there is a scarcity of data. DPTI and
equivalent, which shall then be certified correct by the Contractor and forwarded by the start of the next working day. Details of all        SA Industry wish to move to a situation where the customer can be reasonably sure of receiving at site the product that was asked for. To
materials applied shall be recorded immediately after each spraying &quot;run&quot;.                                                                    work towards this, the following clause was included in the 02/03 season, and will be actively enforced in the successive seasons.
16.      APPLICATION TOLERANCES
Materials shall be applied, or added to, within the following tolerances of the specified rate:
(a) Cutter proportions - &#177; 1.0 parts per 100 parts of bitumen, except that for overspray when cutback is specified the tolerance shall be -
&#177; 1.5 parts per 100 parts of bitumen.
(b) Application of primer, primer binder, binder and overspray shall be within &#177; 5% of the specified rate. For short bar runs and hand
spray work the tolerance shall be &#177; 20%.
(c) Spreading of aggregate shall be within &#177; 5% of the specified rate.
(d) The proportion of adhesion additive used in precoat (specified per 100 parts IDF: 30 parts C170: 1.5 parts approved additive) shall
be within -0.5 to +1.0 parts.
The longitudinal line followed shall be within 50 mm of that specified for straight runs and 100 mm on curved alignments.
17.      TEST PROCEDURES
The Contractor shall use the following test procedures to verify conformance with the Specification:
Laboratory testing of aggregate moisture content is not practical on site and is likely to be only called for to resolve site supervisors
TEST                                                 TEST PROCEDURE                                   differences of opinion.
Oven Drying Method                                   AS 1289.2.1.1
Microwave Method                                     AS 1289.2.1.4
Sampling of Soil, Aggregates and Rocks                                                            TP 226
Determination of Aggregate Stripping Value - One Day Plate Stripping Test                         TP 705
Edition: March 2009                                                                                                                                                  Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
18.      HOLD POINTS
The following is a summary of Hold Points, vide Part 140 &quot;Quality System Requirements&quot;, referenced in this Part:                      These are maximum response times
CLAUSE                                                                                             RESPONSE
REF                                                                                                TIME
2             Submission of Procedures and documentation(if not in Post Tender Submission)         7 days
3.1           Prior to use of sealing aggregates                                                   2 working days
8             Prior to application of prime or primerseal                                          3 hours
9             Prior to application of binder                                                       3 hours
10            Prior to removal of loose aggregate after rolling                                    3 hours
19.      VERIFICATION REQUIREMENTS AND RECORDS
19.1     Test Records
The Contractor shall undertake the testing specified in this Clause and supply written evidence of compliance with the lot package.
CLAUSE                                                  TEST                TEST               ACCEPTANCE
SUBJECT            PROPERTY
REF.                                                PROCEDURE           FREQUENCY               LIMITS
Annually /
3&amp;             Precoat and                                                                       Wet: Max 15%
Stripping             TP 705                 Source of
Part 215       Aggregate*                                                                        Dry: Max 5%
3&amp;             Aggregate                              AS1141.20.1 or
ALD                                          One test per lot    Report Value
Part 215       Properties*                            AS 1141.20.2
3&amp;             Aggregate                                                                         Refer Part 215.
Grading               AS 1141.11             One test per lot
Part 215       Properties*                                                                       Appendix 1
Flakiness             TP 241                 One test per lot
3&amp;             Aggregate        Misshapen                                                        Refer Part 215.
AS 1141.14             One test per lot
Part 215       Properties*      Particles                                                        Appendix 1
Aggregate                              AS 1289.2.1.1                              Non-PMB:
3 &amp; 4.2                         Moisture Content                             On request
Properties                             AS 1289.2.1.4                              0.8%PMB: 0.01%
Paving Fabric    Mass per unit area    AS 3706.1              One per lot         Refer Part 275
13 &amp;                            Wide Strip tensile                           One per lot
Paving Fabric                          AS 3706.2                                  Refer Part 275
Part 275                        strength
13 &amp;                            Maximum                                      One per lot
Part 275                        elongation
13 &amp;                            Binder retention                             One per lot
Paving Fabric                          ASTM D6140-00                              Refer Part 275
Part 275                        rate
Binder and                             As recorded on                             Refer Clause 15
15                              Application Rate                             Per Run
Aggregate                              Daily Record Sheet                         &quot;Tolerances&quot;
Edition: March 2009                                                                                                                             Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
8, 9 &amp;            Supply of
Refer Part 225
Part 225          Bitumen
* Not applicable for aggregate supplied by the Principal.
19.2       Other Records
The Contractor shall supply the following records:
SUBJECT                                RECORD TO BE PROVIDED
15         Records of Work              DPTI 397 &quot;Seal Coat Treatment - Daily Record Sheet&quot;,
20.        MEASUREMENT AND PAYMENT
20.1       Measurement
Measurement of Quantities will be based on DPTI 397 &quot;Seal Coat Treatment – Daily Record Sheet&quot; or an approved equivalent.
For two coat seals, measurement will be determined from the area of the first coat.
Measurement of Cutter will be based on the amount used as recorded in the daily record sheets.
Measurement of Paving Fabric will be based on the final surface area covered, with no allowance for the specified overlaps.
20.2       Payment by Schedule of Rates
This sub-clause applies if payment for sprayed bituminous surfacing will be made by Schedule of Rates.
On an individual sprayer run basis, payment will be made at the rates in the Schedule of Rates for the actual quantities of primer, primer
binder, overspray and binder prepared and sprayed on the road under this Specification at rates of application specified or ordered and
within the tolerances specified.
For individual jobs in this Contract, the unit rates shall apply where the approved proportions and rates are within the ranges set out below
for individual jobs. This does not invalidate the total Contract quantities or the limits of accuracy detailed in the Schedule of Rates.
Proportions of components of primer                     &#177; 25%
Proportions of flux, cutter in binder                   &#177; 100%
Proportion of additive in binder                        &#177; 100%
Application rate for primer                             &#177; 50%
Application rate for overspray                          &#177; 25%
Application rate for binder                             &#177; 15%
Application rate for precoating of aggregate            &#177; 50%
Application rate for aggregate spreading                &#177; 10%
20.3       Payment by Lump Sum
This sub-clause applies if payment for sprayed bituminous surfacing will be made by Lump Sum or part thereof.
Where a direction has been issued to adjust the proportions or application rates, the amount paid will be adjusted by an amount determined
from the applicable rate in the Schedule of Rates for Variations.
Edition: March 2009                                                                                Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
APPLICATION OF SPRAYED BITUMINOUS SURFACING:       APPENDIX 1
VOLUME CONVERSION TABLE - BITUMEN EMULSION
HOT LITRES x A = COLD LITRES (15oC) COLD LITRES x B = HOT LITRES (T oC)
60% BITUMEN EMULSION          70% BITUMEN EMULSION         80% BITUMEN EMULSION
TEMP                          TEMP                           TEMP
A                   B         A                  B         A                 B
(ToC)                         (ToC)                         (ToC)
1.0000      15      1.0000    1.0000      15     1.0000    1.0000       15   1.0000
.9998      16      1.0002     .9977      20     1.0023     .9974       20   1.0026
.9989      18      1.0011     .9951      25     1.0049     .9948       25   1.0052
.9980      20      1.0020     .9924      30     1.0076     .9921       30   1.0079
.9971      22      1.0029     .9899      35     1.0102     .9895       35   1.0106
.9962      24      1.0038     .9872      40     1.0129     .9868       40   1.0134
.9953      26      1.0047     .9840      46     1.0162     .9837       46   1.0166
.9944      28      1.0056     .9830      48     1.0172     .9826       48   1.0177
.9935      30      1.0065     .9819      50     1.0184     .9816       50   1.0187
.9926      32      1.0074     .9809      52     1.0194     .9805       52   1.0199
.9917      34      1.0083     .9798      54     1.0206     .9794       54   1.0210
.9908      36      1.0092     .9788      56     1.0216     .9783       56   1.0222
.9899      38      1.0102     .9777      58     1.0228     .9773       58   1.0232
.9890      40      1.0111     .9767      60     1.0238     .9762       60   1.0244
.9881      42      1.0120     .9752      62     1.0254     .9751       62   1.0255
.9872      44      1.0129     .9746      64     1.0260     .9740       64   1.0267
.9863      46      1.0138     .9736      66     1.0271     .9730       66   1.0277
.9854      18      1.0148     .9725      68     1.0282     .9719       68   1.0289
.9845      50      1.0157     .9715      70     1.0293     .9709       70   1.0300
.9836      52      1.0166     .9704      72     1.0305     .9698       72   1.0311
.9827      54      1.0176     .9693      74     1.0316     .9687       74   1.0323
.9818      56      1.0185     .9683      76     1.0327     .9677       76   1.0334
.9809      58      1.0194     .9672      78     1.0339     .9667       78   1.0344
.9800      60      1.0204     .9662      80     1.0349     .9656       80   1.0356
.9791      62      1.0213     .9651      82     1.0361     .9643       82   1.0370
.9782      64      1.0222     .9640      84     1.0373     .9630       84   1.0384
.9773      66      1.0232     .9630      86     1.0384     .9616       86   1.0399
.9764      68      1.0241     .9619      88     1.0396     .9603       88   1.0413
.9755      70      1.0251     .9608      90     1.0407     .9590       90   1.0427
Edition: March 2009                                                                               Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
APPLICATION OF SPRAYED BITUMINOUS SURFACING:         APPENDIX 2
VOLUME CONVERSION TABLE – HOT BITUMEN-BASED BINDERS
MULTIPLY BY &quot;A&quot; TO REDUCE VOLUME AT T o TO VOLUME AT 15o
MULTIPLY BY &quot;B&quot; TO INCREASE VOLUME AT 15oC TO VOLUME AT To
Multiplier   Temp. oC     Multiplier    Multiplier   Temp. oC       Multiplier
A             T             B            A            T              B
.9856          38          1.0146        .9356         120          1.0688
.9844          40          1.0158        .9344         122          1.0702
.9831          42          1.0172        .9332         124          1.0716
.9819          44          1.0184        .9320         126          1.0730
.9806          46          1.0198        .9308         128          1.0743
.9794          48          1.0210        .9296         130          1.0757
.9782          50          1.0223        .9284         132          1.0771
.9769          52          1.0236        .9272         134          1.0785
.9757          54          1.0249        .9260         136          1.0799
.9745          56          1.0262        .9249         138          1.0812
.9732          58          1.0275        .9237         140          1.0826
.9720          60          1.0288        .9225         142          1.0840
.9708          62          1.0301        .9213         144          1.0854
.9695          64          1.0315        .9201         146          1.0868
.9683          66          1.0327        .9189         148          1.0883
.9671          68          1.0340        .9178         150          1.0896
.9659          70          1.0353        .9166         152          1.0910
.9646          72          1.0367        .9154         154          1.0924
.9634          74          1.0380        .9142         156          1.0939
.9622          76          1.0393        .9130         158          1.0953
.9610          78          1.0406        .9119         160          1.0966
.9597          80          1.0420        .9107         162          1.0981
.9585          82          1.0433        .9095         164          1.0995
.9573          84          1.0446        .9084         166          1.1009
.9561          86          1.0459        .9072         168          1.1023
.9549          88          1.0472        .9060         170          1.1038
.9537          90          1.0486        .9049         172          1.1051
.9524          92          1.0500        .9037         174          1.1066
.9512          94          1.0513        .9025         176          1.1080
.9500          96          1.0526        .9014         178          1.1094
.9488          98          1.0540        .9002         180          1.1109
.9476          100         1.0553        .8990         182          1.1123
.9464          102         1.0566        .8979         184          1.1137
.9452          104         1.0580        .8967         186          1.1152
.9440          106         1.0593        .8956         188          1.1166
.9428          108         1.0607        .8944         190          1.1181
.9416          110         1.0620        .8933         192          1.1195
.9404          112         1.0634        .8921         194          1.1209
.9392          114         1.0647        .8909         196          1.1224
.9380          116         1.0661        .8898         198          1.1239
.9368          118         1.0675        .8886         200          1.1253
APPLICATION OF SPRAYED BITUMINOUS SURFACING:         APPENDIX 3
APPROVED BITUMEN ADHESION ADDITIVES
Megamine NV
Aggr Grip 520LT
Edition: March 2009                                                                                                                                                                                Technical Commentary on Specification: Part 226 Application of Sprayed Bituminous Surfacing
APPLICATION OF SPRAYED BITUMINOUS SURFACING:                                                               APPENDIX 4
DAILY RECORD SHEET – SEAL COAT TREATMENT                                                                       A.E. No.              /
Road Name                                                                                                                                                Date         /        /
Type of Work (e.g. prime, seal, reseal, etc)                                                                                                             Sprayed No.
Location of Work (on this sheet ) From                                                                                                -Wards (insert directions)
Reference to km Post,
Junctions, chainages, etc
Run No.                                           1          2            3             4             5             6            7             8             9             0         Totals
Surface Temp oC
Binder Mix 100/                                   /          /             /             /            /             /             /             /            /             /
Bitumen hot
Flux cold
Cutter cold
Dipstick                   Start
Reading                    Finish
Litres Sprayed
Resid Binder*
Distance                   Start of run
Starting                   End of run
Length of spray …….m
Width of spray ………m
Area sprayed m2
Specified appl. rate *                                                                                                                                                                    l/m2
Specified litres *
Tolerance ……………..*
Difference …………….*
Actual appl. Rate …….*
Spec. coverage                                                                                                                                              m2/m3
Act. Coverage
Precoat (l)
Remarks (alterations to specifications – weather, etc.)                                             No. of Rollers used ............Swept after rolling? Yes/No
DPTI Representative ................................................................. Contractor’s Representative .......................................
APPLICATION OF SPRAYED BITUMINOUS SURFACING:                               APPENDIX 5
GUIDELINES FOR ADDITION OF CUTTER
Cutter is used to reduce the viscosity of the binder, and enhance the initial wetting of the aggregate.
Following the addition of cutter to the binder, the load should be circulated for at least 15 minutes to ensure a uniform mixture
The amount of cutter required will vary with the pavement temperature and the temperature and traffic conditions in the next few days
after application. The Tables show typical cutter addition rates in parts per hundred parts of bitumen
Product                                               PAVEMENT TEMPERATURES (&#186;C)
100:0:y Parts Cutter        15 – 20      20 – 25      25 - 30 30 - 35 35 – 40 40 -50                     50-60   Over 60                       The cutting requirements of PMBs are quite different than that of straight C170. Check to see the requirements for the particular grade
PMB that you are using! Don’t forget to read points 1 – 6!
C170                           6            5            4       3       2      0                          0
C320                           7            6            5       4       3      2                          0        0                          This cutting chart is based on work that was undertaken in 1997, and published as: Maccarrone, Neaylon, Clark &amp; Gnanaseelan “The
Multigrade                     6            5            4       3       2      1                          0        0                          effect of Cutter on the performance of Polymer Modified Sealing Binders”, 10 th AAPA International Flexible Pavements Conference,
S10E                          na            6            5       4       3      2                          0        0                          Perth, November 1997
S15E                          na            7            6       5       4      3                          2        0
S20E                          na            8            7       6       5      4                          3        0                          Another PMB cutting chart worth trialling - in consultation with the Supervising Surfacings Engineer - is APRG Pavement Work Tip No
S35E (SBS based)              na            6            5       4       3      2                          0        0                          27, “Sprayed Sealing – Cutting Back of Polymer Modified Binders”, published April 2001 and available for free download from
S35E (PBD based)               4            3            2       1       0      0                          0        0
S15RF                         na            9            8       7       6      4                          4        4
S18RF                         na           10            8       9       7      5                          5        4
S45R                          na            9            8       7       6      4                          4        4
The only S35E’s that are PolyButaDiene (PBD) based are Mobil and BP formulations, until notified otherwise.
Further changes to the cutter rates may be made on-site to account for:
1.       Weather changes prior to completion of rolling: Treat as for likely conditions.
2.       Time lapse between temperature measurement and actual spray run: Try to anticipate the actual temperature, and cut accordingly.
3.       Age of prime or primer binder (if applicable): If these still contain significant amounts of cutter, the cutting rate may be reduced
by 1 part.
4.       Two-coat crumb rubber seals require a minimum of 4 parts of cutter in the bottom coat. For all other binders no more than two
parts of cutter in the bottom coat is generally required.
5.       Traffic conditions: High traffic volumes and masses require less cutter to achieve wetting. Cutter can be reduced by up to 2 parts
for roads carrying high volumes and percentages of commercial vehicles (e.g. National Highways), particularly in spray runs
completed in the morning, and which will be under traffic control for most of the day. Larger aggregates may require 1 part more
cutter to assist wetting where traffic volume is low.
6.       Pre-blended crumb rubber grades may contain process oil. This oil will most likely reduce the viscosity of the binder compared
to field blended grades; this may allow a reduction of 1-2 parts in the cutting rate.
Wind speed at the time of spraying can affect the rate at which the binder cools. This should be considered when determining the amount
of cutter required.
"Part226 Guidelines"
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