MTO Bituminous Section Report - ON Asphalt. MTO Bituminous Se… · Performance testing of HMA...

Pamela Marks, Anne Holt, Seyed Tabib, and Imran Bashir

May 2016

MTO Bituminous Section Report

2016 Partners In Quality Road Tour London, GTA, Ottawa and Sudbury

Materials Engineering and Research Office

Outline Changes in Specifications

• Asphalt Cement (AC)

• Hot Mix Asphalt (HMA) Materials

• Hot Mix Construction

• SMA Gritting

• Smoothness

• Referee Testing

• Emulsion / Liquid Asphalt

• Granular Sealing

DSM Changes for Anti-Stripping

2


Outline Cont’d Initiatives

• Improving Quality of Asphalt Pavements • Joint Warranty Specification

Trials • FHWA SPS-10 Warm Mix Sections • Fibre Trials • MSCR Trial

Research • Chemical Evaluation of PGAC • Research Studies

3


HMA Specifications

2014 2015/2016

Asphalt Cement 1101 SP111F09

1101 SP111F09

SP111F09M ExBBR SP111F09M MSCR Trial

HMA Aggregate SP110S12 SP110S12

Hot Mix Material 1151 SP111F10

SP111F11

Construction of HMA 313

11 SPs SP103F01

SP103F31 (Smoothness) SP399F02 (Temporary HMA)

4


Sample SP111F09 Table 1 for PG64-28

PGAC Grade Property and Attributes Acceptance Criteria Major Borderline Rejectable

All PGAC Grades (except PG52-40 and PG58-40) Ash Content (%)

≤ 0.8 > 0.8 and ≤ 1.0 >1.0

PG52-40 and PG58-40 ≤ 1.0 N/A >1.0

All PGAC Grades (except PG58-28 and PG52-34)

Non-recoverable creep compliance Jnr-3.2 (kPa-1 ) < 4.5 N/A ≥ 4.5

Average percent recovery, R3.2 (%)

On or above the curve N/A Below

the curve

Difference in non-recoverable creep compliance between 0.1 and 3.2 kPa, Jnrdiff (%)

N/A Testing carried out only for information purposes

CTOD, δt (mm) ≥ 10.0 < 6.0 and ≥ 4.0 < 4.0

PG64-28 and PG58-34

Low Temperature Limiting Grade (LTLG) (°C) N/A

Testing carried out only for information purposes Grade Loss (°C)

5

AASHTO T305, Multiple Stress Creep Recovery (MSCR)

LS-299, Double Edge Notched Tension (DENT)

LS-308, Extended Bending Beam Rheometer (ExBBR)


Asphalt Cement Path Forward Contracts will include SP111F09M Entitled “Additional Test Results

(including Extended Bending Beam Rheometer) and Samples for Performance Graded Asphalt Cement (PGAC)”

In 2016, implement ExBBR test criteria on major road works such as:

• new/expansion construction • reconstruction • major rehabilitation projects with a 15 to 20 year design life, and • works on 400 series freeways, Alternative Financing and

Procurements (AFPs), Trans Canada highways and Connecting Links, as appropriate.

In 2017, implement ExBBR test criteria on above project types plus on select rehabilitation projects with a 10 to 15 year design life

6


Sample SP111F09M ExBBR Table 1 for PG64-28

PGAC Grade

Property and Attributes

Acceptance Criteria

Major Borderline Rejectable

PG64-28 and PG58-34

Low Temperature Limiting Grade (LTLG) (°C) ≤ -28 Note 1

Grade Loss (°C) ≤ 6.0 > 6.0 and ≤ 8.0 > 8.0

7

LS-308, Extended Bending Beam Rheometer (ExBBR)

Note 1: For every lot, AC that has a LTLG value that does not meet the acceptance criteria specified in Table 1 shall be categorized using the lot LTLG in place of the actual low temperature performance grade to determine the deviation from the design Low Temperature Performance Grade


SP111F11 Hot Mix Material Changes include:

• SMA aggregates moved to DSM list with FC aggregates

• Removal of Independent Mix Check

• Relaxation of Ninitial requirement by 0.5 %, constructability remains the Contractor’s responsibility

• Maximum discharge temperature at plant 170°C

• Addition of new one point mix check if mix is to be used for more than 14 months

JMF adjustment no longer requires backup or QA data as justification. Opt-in was offered for current SP103F01 contracts

8


SP103F01 Hot Mix Construction Removal of 12°C requirement for SMA and Superpave

12.5FC2

Bridges and multiple stages to be treated as a separate lot

Clarification of basis of acceptance of small quantity lots

Core density calculation changed to use loose mix MRD

Clarification of how changes in combined aggregate density apply

SMA air voids now included, tiered LL of 90.5 for SP 12.5FC2, 19, 25 and 37.5

9


NSSP SMA Gritting Pause on SMA has been lifted

SMA requires coated gritting material for the SMA surface

Contractor must submit the gradation and physical properties of the gritting material five days prior to start

The spread rate must be verified by a demonstration area

Verify contract quantities to see if shoulders included, need to be wide enough to fit a spreader

Lane marking area not gritted

10


SP103F31 Smoothness Smoothness measurements should not be carried out at

sub-zero temperatures, the results may be unreliable

No paving of surface course permitted till the sublot sketch has been finalized

No changes to the sublot sketch allowed after the paving of the surface course mix has started

Starting in 2016, the use of GPS-DMI technology will be added to LS-296

11


Referee Testing Elimination of outliers for QA, contractor can always

request referee testing

Options for referee of loose mix changed to mix properties or compaction or both.

Full lot or up to 2 sublots, all referee elements on one request per lot

Need to specify if core compaction is by core MRD method or loose mix MRD method, use SP.

Testing of all properties for PGAC in Table 1, no single parameters

12


Emulsified/Liquid Asphalt Specifications Proposed VOC Code of Practice

• It is not recommended to sell, offer for sale, use, manufacture or import cutback asphalt, between May 1 and September 30, that exceeds 0.5% of volume of volatile organic compounds (VOCs)

• Cutbacks still restricted during winter months, but to 5%

• Applies to use in paving material, in paving, construction and maintenance operations, of, for example, roads, streets, highways, parking lots or driveways

• Similar restriction for emulsions - cannot exceed 3% of volume of VOCs

13


Emulsified/Liquid Asphalt Specifications

2014 2015/2016

Liquid Asphalt 1102 No Change

Emulsified Asphalt 1103 SP111S05

Tack Coat 308 SP308F02 No Change

Tall Oil Pitch -- 2510

Granular Sealing 305 SP305S02

14


SP111S05 Emulsified Asphalt New version published in October 2015 added:

• Generic category of “Non-Tracking” tack coat emulsion

• Solvent-free emulsified asphalt for granular sealing

• Emulsified asphalt requirements for micro surfacing

Next Step: Supplier/manufacturer apply to have their non-tracking tack coat products evaluated to be listed on DSM

Non-tracking tack coat still requires change proposal at this time

15


SP305S02 Granular Sealing Granular sealer type chosen by designers

The products are classified into three main types and two subtypes based on performance as follows:

16

Type Description Expected Performance (Years)

I-a RC-30/MTO Primers 4

I-b Emulsified Asphalt Primers (EAP) 4

II Solvent-Free Emulsified Asphalts 3

III Tall Oil Pitch (TOP) Emulsions 2


DSM Changes In early 2015 MTO made revisions requiring the use of

the anti-stripping aggregate treatment type and dosage listed on the DSM

• MTO made these changes based on an emerging stripping issue across the province

• Required amount of hydrated lime from initial approval of aggregate source

• MTO has developed protocol for evaluating alternatives to lime

17


New Anti-Stripping Terminology Anti-Stripping Treatment (AST) means a treatment

used to minimize stripping of asphalt cement from HMA aggregates, and can be either AST-AGG or AST-AC.

Asphalt Cement Anti-Stripping Treatment (AST-AC) means an AST added directly to the asphalt cement to be used in the mix, prior to incorporating it into the mixer at the HMA plant.

Aggregate Anti-Stripping Treatment (AST-AGG) means an AST applied directly to the HMA aggregates prior to incorporating them into the mix or dryer at the HMA plant.

18


DSM 3.05.25 Aggregates: Surface Friction Courses Was Aggregates: Coarse for Superpave 12.5 FC1, Superpave 12.5

FC2, HL1, DFC; Fine for Superpave 12.5 FC2, DFC Approved product must be tested with source in lab and have a

field test section before a lime replacement can be listed

19


Compatibility of Paving Materials

20

Materials Engineering and Research Office 21

Improving Quality of Pavements Survey was sent in 2015 to internal MTO staff

Asked what improvements can be made to the: • design, • materials, and • construction

of our asphalt pavements?

Approximately 100 ideas generated!

Many ideas aimed at increasing the AC content of our Superpave mixes

MTO met with Industry twice to discuss how to increase AC content.


Increasing Asphalt Cement Content Make fine graded 12.5 mixes the default, and coarse

mixes the designer option • MTO is concerned with fine mixes being produced outside the

band • Consider switching to a 2.36 mm sieve as the Primary Control

Sieve (PCS) from the current 4.75 mm sieve

Consider changing VMA, air voids, and gyrations

Need to include incentive for more AC to support utilization of design changes to incorporate more AC

Pay AC content based on lot average not JMF to encourage contractors to put more AC in the mix

22


Other Improvements Being Considered Binder replacement ratio method

Pavement permeability requirement

Performance testing of HMA

Recovered asphalt cement testing

New methodology to establish mixing and compaction temperatures

23


Joint Warranty Specification

Surface course joint warranty NSSP updated to reflect current contract documents • Specification was shared with ORBA and comments received • Will see this in a few contracts this year

Requires: • Five (5) year performance warranty on surface joints • Coarse aggregate loss or ravelling shall not be worse than slight

within 150 mm of any joint • No crack > 3 mm at joint or within 150 mm of the joint. Poor

performing cracks shall be rout/sealed or strip repaired • Less than 20% of previously routed and sealed areas detached

24


FHWA SPS-10 WMA Sections Contract 2016-2023, Highway 48 Five sections for long term performance monitoring

25


Fibre Reinforced HMA There will be several contracts with SP103F01M

specifying fibre reinforced HMA requirements • Designer selects the fibre type. Current options are:

− Forta-Fi Fibres (blend of polyolefin and aramid fibres) − Basalt Fibres − PET Fibres − Other

All current trials have specified Forta-Fi Fibres

26

Forta-Fi Basalt PET


Fibre Reinforced HMA Candidates

27


MSCR Trial Multiple Stress Creep Recovery (MSCR) Trial

• The MSCR trial is to try out the proposed new grading system which replaces the high temperature grade bump with an indicator of traffic

• The choices are S, H, V or E, for Standard, High, Very High, and Extreme

• One contract with an SP111F09M Entitled “Additional Test Results and Samples for Performance Graded Asphalt Cement (PGAC) with PGAC Graded using MSCR Test”

• Contract selected, specified a PG 52H-40 (instead of 58-40); later revised by addendum to PG 52H-34

28


MSCR Trial

29


Research - Chemical Evaluation of PGAC Chemical Evaluation of PGAC with XRF and FTIR

• Contract PGACs are being tested with X-Ray Fluorescence (XRF) and Fourier Transform Infrared (FTIR) technology

• Elements currently analyzed by XRF are: Calcium, Copper, Zinc and Molybdenum

• MTO developed an algorithm to estimate REOB content

• FHWA earlier developed a similar equation based on XRF alone

• The samples were chosen from historical MTO contracts to represent varied REOB contents.

• MTO and FHWA have obtained comparable REOB estimates

30


Estimated REOB Content Comparison

31

Sample FTIR Peak at 1229 cm-1

Estimated REOB By MTO, %

Estimated REOB By FHWA, %

A No 0.1 0 B No 1.3 0 C Yes 4.0 4 D Yes 9.8 10 E No 0 0 F No 1.1 0.5 G Yes 11.7 12 H No 0.4 1 K No 0.1 0.5 L Yes 17.3 16.5


Research Studies Under HIIFP, MTO provides funding to Ontario colleges

and universities to encourage applied research in transportation infrastructure in Ontario

• Effect of Warm Mix Additives on Tensile Strength of Compacted Asphalt Mix - University of Waterloo (2014)

• Refinement of Double Edge Notch Tension Test - Queens University (2014)

• Development of In-Situ Permeability Criteria for Hot Mix Asphalt (HMA) Pavements in Ontario (2014) - Carleton University

• Development of High Modulus Asphalt mix design technology for use on Ontario’s Highways (2015) - University of Waterloo

Special Study: Investigation of Ontario AC Initiative Contracts – Queens University (2015)

32


Questions

33

Pamela Marks Head, Bituminous Section [email protected] Anne Holt Senior Bituminous Engineer [email protected] Seyed Tabib Senior Bituminous Engineer [email protected] Imran Bashir Bituminous Engineer [email protected] 145 Sir William Hearst Drive, Room 238 Downsview, Ontario M3M 0B6

Date post:	17-Mar-2021
Category:	Documents
Upload:	others
View:	4 times
Download:	0 times

MTO Bituminous Section Report - ON Asphalt. MTO Bituminous Se… · Performance testing of HMA...

Documents