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Superpave Implementation Across Canada (1994-2001). Results from the 2001 Canadian Superpave Implementation Tracking Study (C-SITS) Steve Goodman C-SHRP Program Manager. Overview. C-SHRP and Superpave Past C-SHRP Implementation Surveys 2001 Survey Methodology Results Summary
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Superpave Implementation Across Canada (1994-2001) Results from the 2001 Canadian Superpave Implementation Tracking Study (C-SITS) Steve Goodman C-SHRP Program Manager
Overview • C-SHRP and Superpave • Past C-SHRP Implementation Surveys • 2001 Survey Methodology • Results • Summary • Some Current SP Research • The Future of C-SHRP and Superpave
C-SHRP and Superpave • Considerable attention from C-SHRP as major product of SHRP • Equipment purchase assistance • Test roads at Lamont, Hearst and Sherbrooke (low temp. cracking) • 1998 Briefing Tour • Canadian Directory of Resources • Technical briefs, technical briefs and more technical briefs • Implementation surveys
Past Implementation Surveys • 1998 Provincial Agency Survey • Conducted by C-SHRP and Golder Associates • 3 Parts • Superpave testing capability • Implementation Plans • Supply and Construction • Main conclusions • Implementation much slower than US • Some concerns with technology • Some agencies to implement by 2000/01
Past Implementation Surveys • 1999 University Curriculum Study • Survey sent to all Canadian university Civil Engineering Depts. and some technical colleges • 13 of 30 responses • All 13 offered some form of Superpave instruction • Some specific courses, mostly added to existing courses • All provinces covered except BC
2001 C-SITS Survey • Expanded distribution • Provincial and territorial transportation agencies • Numerous municipalities • 2 Parts • Part 1 – Total tonnages by year • Full Superpave • PG Binders with Marshall Design • Part 2 – Detailed Project level data
2001 C-SITS Survey • Part 1 Questions • Tonnages placed 1994-2001 • Full Superpave (as per AI/AASHTO) • PG Binder with Marshall Design • Has your Agency adopted SP? If not, why? • Construction Concerns? • Tenderness, Compaction, Segregation, Pickup, Stripping • Average % increase in cost for SP asphalt • Is cost justified?
2001 C-SITS Survey • Responses • 41 responses (20%) • 10 provinces, 1 federal, 30 municipalities • 19 agencies have experimented with Superpave mix design • All 10 provinces, federal, 8 municipalities • Many of the large municipalities responded • Expected that unresponsive agencies do not have experience
How Much Down? 4.13 million tonnes
4.13 million tonnes Full Superpave • 28.3 million tonnes PG Binder with Marshall design
Why Not? • Limited experience with mix design and testing. • Performance still under evaluation. Mixed results to date. • Used only for high traffic areas. • Scarcity of acceptable aggregates (costs related to aggregate production). • Want to gain experience with PG binders first. • Want to ensure that Superpave does not exclude materials that have provided good performance in the past.
Why Not? • Technical issues • FAA test • Restricted Zone • Software • Absence of performance related test. • Concern with industry’s testing and mix design ability and capacity. • Waiting for acceptance/adoption by Province. • High cost of testing equipment
Why Not? • Low Benefit:Cost Ratio. Current mixes perform well against rutting. Only low temp cracking a concern (PG binders have improved situation) • Will eventually replace Marshall, but gradually.
Concerns Remedied with Experience? • Mostly “Yes” • Comments • Insufficient experience • Handwork difficult • Increased pickup with modified binders (one agency removed rubber tired roller from job) • Some increased segregation with >25mm NMAS mixes
Survey Summary • 2.6 million more tonnes of SP since 1998 • Much faster implementation rate • Municipalities are experimenting with and using Superpave • Only one agency has adopted SP mix design • Many agencies have adopted PG binder spec • West has good crude, use CAN-CGSB specs • Experience has reduced construction problems
Survey Summary • Canadian agencies will likely adopt Superpave • Some outstanding technical issues • Concerns about performance of test sections • Waiting for performance test • Need industry experience and capacity
Some SP Related Work • New RAP Guidelines for SP (NCHRP Research Results 253) • NCAT report on Restricted Zone • Should be a “Caution Zone” or Eliminated Entirely • Simple Performance Test soon (NCHRP 9-19 and 9-29) • Dynamic Modulus (E*)??? • NCHRP Report on Modified Binders (NCHRP 459) • Testing and Inspection Levels for HMAC (NCHRP 447) • Ndesign Table Literature Review (NCHRP Web Doc) • Many online through TRB at and NCAT
The Future of C-SHRP and Superpave • Continue collecting survey information • Look at Part II information with time • Technical Briefs • Superpave vs. SMA? • Results of MTQ/LCPC/Heritage Research Experiment • Any other new technologies/procedures from NCHRP projects • Second Superpave Briefing Tour? • May tie in with AASHTO 2002