Warm Mix Technology The Canadian Perspective J.Keith Davidson P.Eng. McAsphalt Industries Limited Toronto Ontario Canada CUPGA – 2007 – Niagara Falls

Agenda Background Introduction Processes Environmental Data Other Benefits The Future

Background Kyoto Accord Energy prices increasing Stricter environmental rules Emission reductions

Introduction 6 main processes –Aspha-min –Sasobit –Wam Foam –Low Energy asphalt –Astec Process –Evotherm

Aspha-min Process –Eurovia of Germany –Synthetic zeolite (Sodium Aluminum Silicate) –21% water/ white powder –Added to mix at same time as binder –Water spray created slowly which foams binder –Gives increased workability and allows coating at lower temperature –Typically 0.3% added to mix –Temperature drops up to ° C

Sasobit Process –Sasol of South Africa –Paraffin wax made from Fischer-Tropsch process –Different cystalline structure compared to conventional waxes –Melts into binder at 110 ° C –Reduces viscosity of binder –Temperature reductions of 10 to 40 ° C –Typically 1 - 2% added to binder –Improves rutting resistance

Wam Foam Process –Shell has operates the process –2 binder component system –Soft binder and a foamed harder bitumen –Soft binder mixed at 110 ° C– full coating –Hard binder foamed into soft binder coated particles –Blend of hard and soft binder critical to process

Low Energy Asphalt Process Coarse aggregate heated and coated Fine aggregate added at ambient temperature Additives added to AC Foaming action creates lower temperatures Maintains workability and compaction 100°C laydown temperatures typical

Astec Process Foaming kit on double barrel drum plant 10 nozzle system (individually controlled) Up to 500 tph (50 tph/nozzle) 550 US gal water system (skid mounted) Reduction in energy usage Mixing temperature reductions of 30 ° C

Astec Process

Evotherm Process –Non-proprietary technology based on a chemical package –Additives to improve coating, workability, adhesion and emulsification –Two methods of production A high residue emulsion (67-69% PGAC) DAT Concentrate (Dispersed Asphalt Technology) –Injection system

Process Trials 5 Processes in Canada being evaluated Aspha-min Sasobit Wam Foam Astec Process Evotherm

Aspha-min Trials placed in 2005 & 2006 Construction DJL has been the contractor Working with Eurovia Various PG grades used

MTQ Project – 2006 (PG 64-34)

Sasobit In its infancy here Bitumar (AC Supplier) Working with Sasobit Consultant 2 trials –City of Toronto – 300t –City of Ottawa – 3000t

Wam Foam 1 trial in City of Calgary – 2005 LaFarge retrofitted a plant to produce Placed in August in new subdivision –Covered with surface mix –Performed well Mixing and compaction temperatures lowered significantly

ASTEC Process 5 trials this year New plant (double barrel green) Can retrofit existing drum plants Energy reductions (10-15%) Emissions reduction Compaction temperatures 100°C range

Evotherm 3 trials in 2005 – 1700 tonnes 1 Trial in 2006 – 1250 tonnes 7 Trials in 2007 – 9200 tonnes Various PG grades used

Evotherm Emulsion Warm Mix Hot Mix

Evotherm DAT Process Concentrated solution of Evotherm Pumped, metered & injection system Injected into pugmill as AC is added Chemical into AC Creates foaming and disperses chemical

Evotherm DAT Process

Environmental Data – Warm Mix Definite reductions in Greenhouse gases – reductions up to 60% Reductions in fuel usage –10 – 50% reduction Reduction in fumes at paver –Up to 50%

Other Benefits of Warm Mix No mix design issues (Marshall or SuperPave or Hveem) Physical properties equivalent to HMA Performance properties equivalent to HMA Reduced age hardening through plant Longer haul distances Excellent compaction

The Future Tendering of projects Continued expansion of usage of warm mix High RAP mixes Way of the future in our industry

Thank You Questions?