MRS11. Sprayed Bituminous Surfacing (Excluding Emulsion) Narelle Dobson Rob Pollock. #21 Spray Seals Narelle Dobson & Rob Pollock 1

Transcription

1 MRS11 Sprayed Bituminous Surfacing (Excluding Emulsion) Narelle Dobson Rob Pollock #21 Spray Seals Narelle Dobson & Rob Pollock 1

2 Specifications and Technical Standards MRS11, MRTS 11 and Annexure MRTS11.1 MRS 11 - Measurement and pay items, reduced level of service, Principal s materials MRTS 11 - Technical Standards including specific material and construction requirements. Annexure MRTS allows for higher standard, and special project and local regional requirements. #21 Spray Seals Narelle Dobson & Rob Pollock 2

3 Method of Review Review of other SRA specs and Austroads BSARG docs Discussions with ARRB and other SRAs Consultative working group with Users - MR regions and AAPA Broad brush consultation with all MR regions and Major Projects #21 Spray Seals Narelle Dobson & Rob Pollock 3

4 Overview MRS11.11 has been reviewed to address the Requirement for better quality sealing design and construction to reduce the number of seal failures. Update of the specification to include new treatments eg. Crumb Rubber. Aimed to reduce reliance on visual and descriptive terms in favor of test methods eg Measurement of Loose Aggregate. #21 Spray Seals Narelle Dobson & Rob Pollock 4

5 Work Items Work Item Description Unit 5103 Seal, class [class], spray rate [spray rate], [including excluding] supply of binder, [location] Reseal, class [class], spray rate [spray rate], [including excluding] supply of binder, [location] Enrichment, grade [grade], spray rate [spray rate], [including excluding] supply of binder, [including excluding] supply of additives, [location]. litre litre litre 5106 SAMI seal, class [class], spray rate [spray rate], litre [including excluding] supply of binder, [location]. 5107P Supply and addition of adhesion agent. litre 5108P Supply and addition of cutter oil. litre #21 Spray Seals Narelle Dobson & Rob Pollock 5

6 Cl Quantities Additives The quantities of cutter oil and/or adhesion agent, recorded in litres, shall be determined from the tally of actual quantities incorporated into the binder used on the Works as recorded on the spray sheet. Table 2.4 details where additional cutter oil and/or adhesion agent shall be quantified for payment. #21 Spray Seals Narelle Dobson & Rob Pollock 6

7 Table 2.4 Quantities Additives Binder/Application Quantification for Payment (yes/no) Quantification for Payment (yes/no) Quantification for Payment (yes/no) Cutter Oil Adhesion Agent Comments Prime No No not used Cutter oil incorporated into the binder no additional payment Primerseal No Yes Cutter oil incorporated into the binder no additional payment Seal and Reseal Yes Yes SAMI Yes Annexure provision Yes Enrichment No not used No not used #21 Spray Seals Narelle Dobson & Rob Pollock 7

8 Table 3.3-A Reduction in Value, Actual Spray Rate % Difference from % Reduction in Value Adjusted Designed Spray Rate plus or minus 6 4 plus or minus 7 8 plus or minus 8 12 plus or minus 9 16 plus or minus #21 Spray Seals Narelle Dobson & Rob Pollock 8

9 Table 3.3-B Reduction in Value, Actual Cover Aggregate Spread Rate % Difference from Adjusted Designed Spread Rate Lighter Spread Heavier Spread 11 to to to to to to % Reduction in Value for Range #21 Spray Seals Narelle Dobson & Rob Pollock 9

10 Definition of Terms New definitions - eg for SAM, SAMI, double/double seal, homogenous section Seal Designer Seal Designer's Delegate A competent, trained designer who shall complete the seal design and shall determine the Designed Spray Rate and the Designed Spread Rate. The Seal Designer shall have successfully attained the Australian Asphalt Pavement Association (AAPA) Statement of Attainment (prior to 2008 called Certificate of Attainment) for the course titled Sprayed Sealing Selection and Design. A competent, trained nominee of the seal designer who may modify, on behalf of the Seal Designer, the Designed Spray Rate and/or the Designed Spread Rate as follows determine the Adjusted Designed Spray Rate; determine the Adjusted Designed Spread Rate; and determine the parts of cutter oil to add prior to spraying. The Seal Designer's Delegate shall have successfully attained the Australian Asphalt Pavement Association (AAPA) Certificate of Attendance at the course titled Sprayed Sealing Selection and Design. #21 Spray Seals Narelle Dobson & Rob Pollock 10

11 Test Methods Property to be Tested Field spread rate of cover aggregate Average Least Dimension Ball Penetration Aggregate Flakiness Index Bitumen Stripping Value Modified Plate Degree Aggregate Precoating Modified Surface Texture Depth (Pestle Method) ( sand patch ) Measurement of loose aggregate on sprayed seals Particle Size Distribution Sampling of polymer modified binders, polymers including crumb rubber at point of discharge to project Sampling of residual bitumen at point of discharge to project Method Number Q711A Q202 AGPT/T251 Q201B Q212B Q216 AGPT/T250 AGPT/T452 Q103B AGPT/T101 AS 2008 Appendix B #21 Spray Seals Narelle Dobson & Rob Pollock 11

12 Table 5.1 Hold Points, Witness Points New Hold Points: Excessive Ball Penetration test results. Loose aggregate/ signage requirements prior to opening to traffic. New Witness Points: Care of cover aggregate Binder storage temperature measured and recorded at delivery to site. Current Queensland Sprayer Certificate to be sighted and nozzles to be appropriate. Loading of cover aggregate into aggregate spreader #21 Spray Seals Narelle Dobson & Rob Pollock 12

13 Cl 5.2 Crumb Scrap Rubber Contractor construction practices required for Manufacture, storage, handling and spraying of field blended or plant blended crumb rubber where this binder is to be sprayed. The construction procedure shall address at least The method for achieving a homogeneous product that can be sprayed at a uniform application of binder across the pavement, free of streaking; The management of crumb rubber blending, digestion, and storage times and temperatures; The maximum time/temperature conditions that field produced/plant blended product can be stored and/or transported without loss of properties as indicated by the Australian Asphalt Pavement Association Code of Practice: Manufacture, Storage and Handling of Polymer Modified Binders; The maximum distance that the product can be transported from a blending site without loss of properties as indicated by the Australian Asphalt Pavement Association Code of Practice: Manufacture, Storage and Handling of Polymer Modified Binders; Circulation of the product during transportation; and Requirements for spraying plant and spraying practices including adjustments to nozzles if required. #21 Spray Seals Narelle Dobson & Rob Pollock 13

14 Cl Seal Design Method Seal designs shall be determined in accordance with the requirements of Austroads Technical Report AP-T68/06 Update of the Austroads Sprayed Seal Design Method. #21 Spray Seals Narelle Dobson & Rob Pollock 14

15 Cl 6 Testing Seal Design Inputs Property to be Tested Test Location(s) Minimum Test Frequency Particle Size Distribution Aggregate Flakiness Index Average Least Dimension The test samples shall be sourced from the stockpiles to be directly used for the works. Modified Surface Texture Depth Ball Penetration In and between the wheelpaths that is, 3 tests at each test chainage. In the inner and outer wheelpaths- that is, 2 tests at each test chainage. Testing is required only for a) pavements in accordance with Clause ; b) primed or primersealed surfaces; and c) asphalt or slurry surfacings less than 6 months old. Test frequency shall be one test for each aggregate type; and repeat tests at every 2500 tonnes. Test frequency shall be the greater of 1 every 400 m; or 2 3 test chainages per homogeneous section where the test sites selected are representative of the homogeneous section. Test frequency shall be 5 test chainages per homogeneous section where the test sites selected are representative of the homogeneous section. Testing shall be completed between 24 to 48 hours prior to spraying. #21 Spray Seals Narelle Dobson & Rob Pollock 15

16 Cl Contractor Seal Design Report The seal design report to detail test results, assumptions, inputs, the design method and calculations that were used to determine the Designed Spray Rate and the Designed Spread Rate; seal design binder types, aggregate types, reference and location Designed Spray Rate of bituminous material and the Designed Spread Rate of cover aggregate, For double/double seals, the minimum period between bituminous treatments as required in the seal design method; nomination of the Seal Designer s Delegate #21 Spray Seals Narelle Dobson & Rob Pollock 16

17 Cl Selection of Additives/Cutter For each lot or homogeneous section, at the time before spraying commences, the Seal Designer s Delegate shall determine the adjustments to be made to arrive at the Adjusted Designed Spray Rates and any addition of additives including cutter and the Adjusted Designed Spread Rates. The Seal Designer's Delegate shall record these adjustments and modifications on the Contractor's spray sheet. (Witness Point) #21 Spray Seals Narelle Dobson & Rob Pollock 17

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19 Cl 7.1 Payment of Binder Contractor-supplied bitumen, multigrade bitumen and polymer modified binder shall be sampled, tested and comply with requirements detailed in Table 7.1 [parent spec]. For payment for supply of these binders, the additional requirements of Clause 4.2 of Annexure MRTS11.1 apply, where either Payment shall be made for complying binder sampled at the point of release by the manufacturer in accordance with the requirements of either MRTS17 or MRTS18 as applicable; or Payment shall be made for complying binder sampled at the point of delivery to Site in accordance with the requirements of either MRTS17 or MRTS18 as applicable. #21 Spray Seals Narelle Dobson & Rob Pollock 19

20 Cl 8.2 Protection of Cover Aggregate Unless otherwise stated in Clause 4.3 of Annexure MRTS11.1, cover aggregate, except for prime cover material, shall be protected with a light plastic or similar material to prevent the ingress of moisture and other contaminants. The protective material shall be sufficiently anchored to ensure the optimal fixture that can be achieved consistent with the protective material properties. #21 Spray Seals Narelle Dobson & Rob Pollock 20

21 Cl Storage of Bitumen Bituminous materials shall be stored and transported in purpose-built containers in such a way that any change to material properties are within the limits specified in the respective bituminous material Standard. If a property change outside the specified limits is suspected, the Administrator may order testing to be carried out in accordance with relevant Standards to check for contamination Binder that has been held in storage shall not be used (either mixed or unmixed) unless records are kept, made available to and acceptable to the Administrator. #21 Spray Seals Narelle Dobson & Rob Pollock 21

22 Cl Incorporation of Additive Where additive is used the additive shall be dissolved in hot binder; and the hot binder and additive shall be circulated, after the addition of the last component, at a rate of at least 1000 litres per minute for a period until the sprayer contents have been circulated twice. Where adhesion agent is to be used, the binder shall then be sprayed as promptly as field circumstances allow and within three hours. If the binder and adhesion agent has not been sprayed within three hours, additional adhesion agent may be added to the remaining binder at a dosage concentration then equivalent to one third of the original adhesion agent dosage. #21 Spray Seals Narelle Dobson & Rob Pollock 22

23 Cl 9 Plant Update to modernise to current practices/equipment for example, drag brooming, accommodate new variable sprayers Cl 14.4 On each day of spreading, each spreader shall be tested in accordance with the Field Spread Rate of Cover Aggregate test (Q711A) and shall comply with the spread rate tolerance requirements of Clause The test frequency shall be one test per spreader per day. #21 Spray Seals Narelle Dobson & Rob Pollock 23

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25 Cl Ball Penetration test on new granular pavements For initial seals on new granular pavement layers, Ball Penetration testing shall be completed in accordance with the requirements of Table 6.2 on the following surfaces after priming; or before primer sealing. Where a Ball Penetration test result exceeds 4.0 mm, the surface shall not be sprayed until approved by the Administrator. Hold Point 5 #21 Spray Seals Narelle Dobson & Rob Pollock 25

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27 Cl 11.2 Pavement Surface Temperature Spraying shall not commence until the temperature of the pavement surface shall be rising or stable and is above the temperature given in Clause 6.2 of Annexure MRTS11.1 or, if not so given, the pavement surface temperature shall be rising or stable and above Witness Point 10 C for primes; 15 C for primer seals; or 20 C for bitumen and polymer modified binders. With the approval of the Administrator, and where the Contractor undertakes sufficient construction practices to ensure adhesion of the binder to the underlying pavement substrate and to the cover aggregate, this limit may not apply to seals that are overlayed with a final asphalt surfacing prior to trafficking. #21 Spray Seals Narelle Dobson & Rob Pollock 27

28 Cl 11.4 Time Periods Between Seals Unless stated in Clause 6.3 of Annexure MRTS11.1 A prime shall not be covered with another bituminous treatment until both of the following conditions are satisfied The prime shall be completely dry and only trafficked by light construction traffic (< 20 vehicles per day); and The prime has been placed for a minimum period of 3days. All traffic shall be kept off the primed surface unless prime cover material has been applied; Between cutback primerseal or a bituminous treatment containing cutter oil and subsequent bituminous treatment (including seal and asphalt) at the same location, the minimum period is 3 months in warm weather (minimum nightly temperatures > 10ºC); and at least 6 months in cooler conditions (minimum nightly temperatures 10ºC), #21 Spray Seals Narelle Dobson & Rob Pollock 28

29 Cl 11.4 Time Periods Between Seals Prior to asphalt overlay, SAMI seals shall not be left exposed for more than 2 days when subject to traffic other than construction vehicles. Where SAMI seals are trafficked by only construction traffic, aggregate removed from the SAMI binder by construction traffic shall be replaced prior to asphalt overlay; and For single/single seals with a locking coat, the locking coat aggregate shall be applied on the same day. For double/double seals, the time periods between bituminous treatments shall comply with: For seal designs completed by the Principal, as stated in Clause 6.4 of Annexure MRTS11.1; and For seal design s completed by the Contractor, as stated in the Contractor s seal design report. #21 Spray Seals Narelle Dobson & Rob Pollock 29

30 Cl 12.7 Cutting Back PMBs Table 12.7-B Cutting Practice for PMBs Pavement Temperature ( o C) (Note 3) 20 to to to to 45 Traffic Volume (vehicles per lane per day) (Note 2) < < < < Cutter Proportion (Note 1) for PMB Class S0.25S S0.7S S0.3B S1.8R (Note 4) Minimum 2 Minimum S15RF S18RF - - > 45 All traffic Minimum 2 Minimum Minimum Notes to Table 12.7-B 1. Parts of cutter oil to 100 parts of bitumen by volume at 15ºC. 2. Based on AADT. 3. Pavement temperatures used to determine the amount of cutter oil shall be based on the worst conditions i.e. shaded areas of pavement. 4. Pre-blended crumb rubber (R classes) may contain process oil used in their manufacture. This oil shall most likely reduce the viscosity compared to field blended rubber (RF classes), and may allow a small reduction, i.e. 2 parts, in added cutter oil #21 Spray Seals Narelle Dobson & Rob Pollock 30

31 Cl 12.7 Time Limit for Spreading Cover Aggregate The spreading of cover aggregate shall commence as soon as possible after the spraying of the binder. Under no circumstances shall any portion of the binder be left without cover aggregate after spraying for longer than the following for primerseals: 15 minutes; for C170, M500/170 and C320 seals: 10 minutes; or for polymer modified binders including crumbed rubber binder: 5 minutes. #21 Spray Seals Narelle Dobson & Rob Pollock 31

32 Cl Rolling Speed The initial passes shall be done at a low speed (5 10 km/h) to achieve the aim of pressing the aggregate into the binder. After that, the rolling speed shall be increased to between km/h to move and reorientate the aggregate particles to their correct position. #21 Spray Seals Narelle Dobson & Rob Pollock 32

33 Cl Roller Coverage Table Area that can be effectively rolled per hour with each self propelled multi-wheeled roller for bitumen and multigrade binders Aggregate size (mm) Traffic Volume (vehicles per lane per day) < > 1200 Area m 2 per roller hour (Note 1) 7 or smaller Table Note 1 'roller hours' is defined as the product of the number of specified rollers by hours of application #21 Spray Seals Narelle Dobson & Rob Pollock 33

34 Cl Number of Roller Passes The minimum number of rubber-tyred roller passes shall be as stated in Clause 7.3 of Annexure MRTS11.1, or if not so stated For bitumen and multigrade binders, the greater of six passes; and the number of passes required to achieve the minimum amount of rolling that satisfies the requirements of Table as a continuous operation with successive spray runs, For polymer modified binders that are not SAMI seals, the greater of nine passes; and the number of passes plus 50 % more than are required for the minimum amount of rolling that satisfies the requirements of Table as a continuous operation with successive spray runs, For polymer modified binders that are SAMI seals, the greater of twelve passes; and the minimum number of passes plus 100 % more than are required for the minimum amount of rolling that satisfies the requirements of Table as a continuous operation with successive spray runs. #21 Spray Seals Narelle Dobson & Rob Pollock 34

35 Cl 14.6 Loose Aggregate Determined in accordance with Austroads test method AGPT/T452: Measurement of Loose Aggregate on Sprayed Seals Location Urban Area Other medium to high traffic (greater than or equal to 250 vehicles/lane/day) Low traffic (less than 250 vehicles/lane/day) Maximum Allowable Loose Aggregate Particles 20 particles/m2 30 particles/m2 40 particles/m2 #21 Spray Seals Narelle Dobson & Rob Pollock 35

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37 Cl 14.7 Protection Fresh Seals The Contractor shall take precautions to protect the work from damage until such time as the prime or seal (including primerseals, new seals, reseals and SAMI seals) has developed sufficient strength to carry normal traffic without dislodgement of the cover aggregate or cover material, as applicable. Special attention is required at intersections. #21 Spray Seals Narelle Dobson & Rob Pollock 37

38 Cl 14.8 Early Trafficking Unless otherwise stated in Clause 8 of Annexure MRTS11.1, the Contractor shall complete the following early trafficking minimum requirements in order to address both loose stone considerations in accordance with Clause 14.6 and the protection of the fresh seal from traffic in accordance with the requirements of Clause 14.7 In areas where the posted speed limit is equal to or less than 60 km/h and which are opened to traffic prior to final sweeping, the Contractor shall install temporary 'loose stones' and 'slippery' warning signs and temporary 40 km/h speed signs until the maximum allowable loose aggregate requirements of Clause 14.6 are met; etc #21 Spray Seals Narelle Dobson & Rob Pollock 38

39 Cl 16 Construction Compliance Compliance of Materials and Construction The Contractor and Administrator shall jointly investigate and provide the Principal with a written report on the causes where any of the following occurs on more than 10% of any wheel path length of any run at any time to the end of the Defects Liability Period Stripping which is defined as areas where more than 10% cover aggregate has been lost from the seal s aggregate matrix; Flushing which is defined as where surface texture depth is < 0.5 mm when tested by AGPT/T250; and/ or Debonding which is defined as separation of the seal from the underlying layer. #21 Spray Seals Narelle Dobson & Rob Pollock 39

40 Cl 16.2 Surface Texture Except for SAMI seals, where the seal is the final surfacing or shall be opened to public traffic, surface texture shall be tested, recorded and reported to the Administrator Sand patch method Range of test frequencies #21 Spray Seals Narelle Dobson & Rob Pollock 40

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43 Underlying pavement type Regional Variations Variable spray rate Geotextiles Traffic Count Heavy Vehicles #21 Sprayed Seals 2

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45 Cl 4 Requirements for Materials 1 REQUIREMENTS FOR MATERIALS 1.1 Cover Aggregate Adhesion Agent (Table 7.1) Adhesion agent shall conform to the following requirements. 1.2 Compliance and Payment of Binder (Clause 7.1) Contractor-supplied bitumen, multigrade bitumen and polymer modified binder shall comply with MRTS17 or MRTS18 requirements, as applicable, at the following locations: Binder Type/Class/Grade Compliance Point for Payment of Binder Point of Release from the Point of Delivery Manufacturer #21 Sprayed Seals 4

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