Use of normal propyl bromide solvents for extraction and recovery of asphalt cements

Details

• Creators:
  Nelson, JW ; Stroup-Gardiner, M
• Corporate Creators:
  Auburn University. Department of Civil Engineering
• Subject/TRT Terms:
  Aggregates Asphalt Cement Binder Recovery Binders Hot Mix Paving Mixtures Materials Recovery (Mining) Normal Propyl Bromide Properties Of Materials Resource Extraction Solvents Superpave

  More +
• Publication/ Report Number:
  NCAT Report 00-06
• Resource Type:
  Research Paper
• Corporate Publisher:
  National Center for Asphalt Technology (U.S.)
• Abstract:
  Four normal propyl bromide (nPB) solvents were evaluated for use as chlorinated solvent replacements in typical hot mix asphalt (HMA) extraction and recovery processes. The experimental design included one method of extraction (centrifuge), one method of recovery (Rotavapor), five solvents (TCE and four nPB products), and six combinations of asphalts and aggregates (PG 46-34, PG 64-22, PG 76-22 (polymer modified); limestone, granite aggregates). Superpave binder properties were determined for the original as well as the recovered binders. A full experimental replicate was conducted so that a statistical comparison of means could be used to evaluate the effect of solvents on recovered binder properties. Results show that when recovered binder properties were compared, there were few instances of statistically different values. When recovered binder properties were compared to the original binder properties, the TCE solvent combined with the extraction and recovery processes occasionally produced higher (i.e., stiffer) recovered binders. One nPB product appeared to be incompatible with the polymer modified PG 76-22. This was seen as a distinct stringy, rubber-like residue in the extractor. Data indicate that nPB solvents can be used as direct replacements for the chlorinated solvents historically used for HMA extraction and binder recovery. There are limited differences in binder properties due to the different nPB solvent products. Neither the testing time nor solvent quantity changed significantly when compared to the TCE solvent. Because there may be some nPB product-specific problems with polymer modified asphalts, initial comparisons of results for both a standard chlorinated solvent and a specific nPB product should be made before accepting an nPB product as a chlorinated solvent replacement.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:af7521314ef1e6915179f4ad4de88cef83f1e7269a972e98c46a3e5c85b81fe2
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/14502/dot_14502_DS1.pdf
• File Type:
  [PDF - 282.51 KB ]