Development of Apparent Viscosity Test for Hot-Poured Crack Sealants

Current crack sealant specifications focus on utilizing simple empirical tests such as penetration, resilience, flow, and bonding to cement concrete briquettes (ASTM D3405) to measure the ability of the material to resist cohesive and adhesion failures. There is, however, no indication of the pertinence of these standard tests to predict the success of field installation and sealant performance. In an effort to bridge the gap between sealant fundamental properties and field performance, performance-based guidelines for selection of hot-poured crack sealants are currently being developed. This report focuses on the development of the apparent viscosity test method. This test uses a modified version of the Brookfield rotational viscometer. Based on the results of this study, the measured apparent viscosity of hot-poured crack sealant using SC4-27 spindle at 60rpm (20.4s-1) at the recommended installation temperature was determined to be reasonably representative of sealant viscosity at shear rates resembling field application. To ensure measurement consistency and stability, a 20min melting time and a 30-s waiting time prior to data collection are recommended. To establish precision and bias for the test, a round robin testing was conducted among seven laboratories. Average coefficient of variation within and between laboratories was found to be 2% and 6%, respectively. Using the data from the round robin testing, and based on ASTM precision and bias standard (ASTM practices C802 and C670), maximum permissible differences within a laboratory and between laboratories were found to be 4.6% and 16.9%. Considering the high polymer or crumb rubber content in crack sealants and sealant temperature sensitivity, the repeatability and reproducibility of the developed test is within an acceptable range. These values are comparable to those of asphalt binder: 3.5% and 14.5% based on ASTM D4402-02 and 3.5% and 12.1% based on AASHTO 2006 T316.


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  • Accession Number: 01142046
  • Record Type: Publication
  • Report/Paper Numbers: ICT-08-027, UILU-ENG-2008-2015
  • Contract Numbers: VTRC Project # 67775 TPF-5(045)
  • Created Date: Oct 6 2009 11:45AM