Plant-mixed lightly bound pavements specification: Proposed MRTSXX

Transcription

1 Plant-mixed lightly bound pavements specification: Proposed MRTSXX Information session Stephen Hulme - A/Principal Engineer (Pavements and Materials Development) 1

2 2 Our values, our diversity

3 Queensland Government s objectives for the community Advance Queensland 3

4 Our strategic plan 4 Plant-mixed Lightly Bound Pavements

5 About us Creating a single integrated transport network accessible to everyone As at 30 June 2016 we manage: As at 30 June 2016: As at 30 June 2016 there were: 33,343km state-controlled roads 3.5m drivers licensed 5m vehicles registered 3,260 taxis licensed 180m in SEQ 12.1m outside SEQ trips taken annually on bus, rail, ferry and light rail 3,029 bridges 256,151 recreational vessel registrations 997,289 boat licenses 20 ports 3.63m customers served face-to-face at 59 Customer Service Centres Our customers conducted 6.68m online services 2.5m go cards in use Over 490,000 passengers travel on the south-east Queensland network on average each day 5 Plant-mixed Lightly Bound Pavements

6 Specification overview Unbound Pavements Plant-Mixed Lightly Bound Pavements Plant-Mixed Cement Stabilised Pavements Lightly Bound Base (Previously ET05C) Lightly Bound Improved Layer (Previously PSTS103) MRTS05 and MRTS35 MRTSXX (2017) MRTS08 and MRTS35 6

7 What are lightly bound pavements? Lightly bound base Previously known as cement modified base or CMB UCS days Max Design Modulus 500 MPa (Sublayered) Plant-mixed Lightly bound improved layer UCS days Max Design Modulus 210 MPa Plant-mixed UCS = unconfined compressive strength Surfacing Lightly Bound Base Unbound Granular Subbase Subgrade Surfacing Asphalt Base Lightly Bound Improved Layer Subgrade 7 Plant-mixed Lightly Bound Pavements

8 Contractor s mix design Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Contractor nominates Mixing Plant Variability Contractor undertakes mix design UCS testing Contractor determines acceptable range for Target Content of stabilising agent Contractor nominates Target Content of stabilising agent Contractor documents and submits Mix Design Report Mix Design report is reviewed and accepted by the Administrator - MILESTONE AND HOLD POINT The Administrator does not specify or direct the % of stabilising agent. Likewise a separate work item is not scheduled for supply of stabilising agent 8

9 Mixing Plant Variability (MPV) An estimate of the likely variability in modifying agent that can be expected during production. MPV Z * σ (where historic results are available) MPV 0.5 (where no historic results are available) 9 Not a measure of how good your pug mill is Plants with higher MPV s can be used with the right binders The MPV requirement is a MINIMUM only the Contractor can select a value higher than this

10 Mix design example 10 Contractors nominated MPV : 0.25% Acceptable range of target content = 1.0% 1.5% Contractor nominates a target content between % (eg.1.2%) Tolerance on actual stabilising agent content limits: nominated target content ± MPV (eg. 0.95%~1.45%)

11 Unbound materials Lightly bound base Default Specified, unless otherwise varied by the Annexure Permissible Material Grading Envelope Specification Subtype 2.1 Grading C MRTS05 Min. Plasticity Index (PI) = 2 or Min. Linear Shrinkage (LS) = 1.5% Lightly bound improved layer Nominated by the Contractor, unless otherwise nominated in the Annexure Contractor can choose from: Permissible Material Subtype 2.1, Subtype 2.2 or Subtype 2.3 RM001, RM002 or RM003 Specification MRTS05 MRTS35 11

12 Binders and additives Stabilising agent: Nominated by the Contractor, as: Cement (GP) Blended Cement (GB), or a Cementitious Blend Selection of binder is performance based, however slower setting binders are typically preferred Admixtures: Nominated by the Contractor as required Most likely set-retarder (Q136 results to support an increase in working time). 12

13 Allowable working time The lesser of: working time determined by Q136, and 4 hours. The Administrator may approve increasing the working time to > 4 hours only where significant constraints exist, such as: Night works in urban areas when pug mill is unable to operate (for example, due to noise restrictions) no suppliers available locally, and requires extended travel times (In these circumstances, allowable working time may be approved up to the working time determined by Q136) 13

14 Conformance requirements UCS UCS Conformance assessed on 7 days test results The contractor determines the relationship between 7 and 28 day UCS values 14

15 Conformance requirements Product tests for bound materials are taken ex. Plant Field conformance is controlled through working time testing Therefore: working time = 3.8 hours 15

16 General construction requirements Proof rolling RMS Test Method T198 adopted NATA accreditation not required Acceptable plant: Pneumatic-tyred static roller (4.5t per tyre) commonly called a multi, or 10,000L loaded water truck. 16

17 General construction requirements Ball penetration Additional requirements to MRTS11 Maximum 3.0mm (average value) Individual values to be assessed for variability within the lot Type 1 ball penetrometer (Photo: Austroads AGPT-T251-10) Type 2 ball penetrometer (Photo: Austroads AGPT-T251-10) 17 Plant-mixed Lightly Bound Pavements

18 General construction requirements Surface finish Detailed finished surface requirements added/clarified Construction joints Longitudinal joint Minimum 150mm offset between layers Final layer - within 300mm of traffic lane marking Transverse joint Minimum 2.0m offset between layers Cracking is more likely to occur if joints are not offset (Photo: Austroads AGAM05E-06) 18 Plant-mixed Lightly Bound Pavements

19 General construction requirements Preparation between layers: Hard Cutting Cement slurry 19

20 General construction requirements Water curing 20

21 General construction requirements Layer thicknesses: mm (previously ) Lightly bound base to be paver placed (Improved layer exempt) 21

22 Default testing frequencies Added as Appendix A of MRTSXX Promote consistency across projects Provide sufficient, but not excessive testing for most projects May be adjusted in Annexure MRTSXX.1 to suit project specific requirements. Maximum Lot Sizes Specified in Table A1 22

23 Default testing frequencies Unbound Material Testing Refer MRTS05/MRTS35 (or other) Product Testing Specified in Table A2. 23

24 Default testing frequencies Construction Testing Specified in Table A3 24

25 Default testing frequencies Geometrics Testing Specified in Table A4 25

26 Thank you and stay connected LinkedIn Blog Department of Transport and Main Roads blog.tmr.qld.gov.au 26