Project 0-4681
Further Development of Binder Quality Assurance Program
Abstract
The current TxDOT binder QC/QA system uses two asphalt binder supplier categories;
suppliers who have an approved quality control plan (QCP) on file with TxDOT and those
who do not. Suppliers who maintain a current QCP can obtain approval to supply binders
either on a monthly- or a quantity-basis, while for others, each load of asphalt must
be tested for specification compliance. Recently, a few binder supplier-grade combinations
have experienced higher failure rates than in the past. Many TxDOT practitioners indicate
an approved binder source does not always provide acceptable quality binders, and
that a more robust QC/QA system is needed to ensure the supply of binders that both
meet specifications and maintain a consistent level of quality. This research project
was launched to develop a quality management system that utilizes the latest QC/QA
principles by sharing the quality management burden between the supplier and the client
(TxDOT). First, TechMRT researchers undertook a constructability review of binder
quality for TxDOT operations. TxDOT districts, along with binder suppliers, and several
contractors were interviewed to solicit their viewpoints on the existing binder quality
management program, binder usage, quality problems and possible solutions. The Researchers
also performed a comprehensive statistical analysis of binder test data. Three years
of TxDOT test results (QA data) and several years of supplier (QC) data were analyzed
using several statistical quality control methodologies. A sound binder supply quality
management scheme requires the cooperation between binder suppliers and TxDOT. The
burden of producing an asphalt binder that both meets specifications and
maintains a consistent level of quality lies primarily with the supplier. TxDOT has
the responsibility to provide clear and specific guidelines for suppliers to follow,
and to conduct random quality assurance tests. Based on this premise, the research
product titled A Framework for TxDOT Binder Quality Management has been developed.
Project PI: Sanjaya P. Senadheera, Ph.D.
Center for Multidisciplinary Research in Transportation (TechMRT)
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Address
Texas Tech University, Box 41023, Lubbock, TX 79409-1023 -
Phone
806.742.3523 -
Email
techmrt.outreach@ttu.edu