Characterization of Unmodified and SBR Latex-Modified Evotherm(tm) Warm Mix Binder

The Evotherm(r) warm mix process developed by MeadWestvaco is the direct substitution of asphalt binder with a cationic asphalt emulsion. Field trials by McAsphalt in Canada have demonstrated a 30 deg C and 60 deg C reduction in the mixing and compaction temperatures, respectively, when compared to conventional hot mix using the same aggregate and asphalt. A procedure to recover the representative emulsion residue for the Evotherm(r) warm mix system was developed. Here, approximately 80g of Evotherm emulsion is poured into a Thin-Film Oven Test (TFOT) pan and dried in a forced air oven at 80 deg C for 20 hours. Results of conventional and Superpave binder characterization testing demonstrate that the recovery procedure developed here closely simulates the heat history that the Evotherm emulsion is exposed to during mixing and paving in the field and further indicate that pavement constructed using unmodified Evotherm warm mix binder after 10-15 years of in-service life would be as flexible as freshly-placed conventional hot mix pavement. The polymer network formed in the SBR latex-modified Evotherm residue does not prevent oxidation of the asphalt binder, but rather reduces the net effect of undesired changes in rheological properties of the asphalt binder upon age or oxidative hardening. Thus, modification with SBR latex polymer is expected to further prolong the service life of the Evotherm warm mix asphalt pavement. (A) For the covering abstract of this conference see ITRD number E220283.

• Authors:
  • DAVIDSON, J K
  • LUBBERS, C
  • TAKAMURA, K
• Publication Date: 2007

Language

• English

Media Info

• Pagination: 297-324
• Serial:
  • PROCEEDINGS OF THE FIFTY-SECOND ANNUAL CONFERENCE OF THE CANADIAN TECHNICAL ASPHALT ASSOCIATION (CTAA): NIAGARA FALLS, ONTARIO, NOVEMBER 2007
  • Publisher: POLYSCIENCE PUBLICATIONS INC

Subject/Index Terms

• TRT Terms: Admixtures; Bitumen; Bituminous mixtures; Conferences; Durability; Emulsions; Evaluation; Field tests; Foamed materials; Polymers; Temperature
• Geographic Terms: Canada
• ITRD Terms: 4736: Admixture; 4993: Bitumen emulsion; 4967: Bituminous mixture; 8018: Canada; 8525: Conference; 5910: Durability; 9020: Evaluation (assessment); 6226: Field (test); 4974: Foamed bitumen; 7482: Polymer; 6722: Temperature
• Subject Areas: Data and Information Technology; I31: Bituminous Binders and Materials; I33: Other Materials used in Pavement Layers;

Filing Info

• Accession Number: 01220207
• Record Type: Publication
• Source Agency: TRL
• Files: ITRD
• Created Date: Oct 27 2010 10:03AM