TRANSPORTATION RESEARCH DIGEST
ARIZONA TRANSPORTATION INSTITUTE
Process for Selecting Innovative Quality Assurance Practices for Materials in Transportation Research Record 1900 by Paul E. Benson (Transportation Research Board, 2101 Constitution Avenue, N.W., Washington, D.C. 20418; ph. 202-334-2934; ) (2004).
Use of this structured, proactive process, under way in California, is one effective way to overcome institutional barriers and implement innovative practices for assuring materials quality.
Recent state legislation empowers the California Department of Transportation (Caltrans) to exclude from public works contracts any parties that willfully conceal. Misrepresent, or alter quality control (QC) findings. To implement this legislation, Caltrans initiated an internal review of its materials quality assurance (QA) program, including an evaluation of the potential for instituting innovative QA practices. This paper documents the review process, the design of a structured procedure for evaluating innovative practices, and the requirements for a materials management system (MMS) needed to implement many of these practices.
The MMS will offer both managers and researchers a wealth of information. For example, information on test scheduling and reporting can be used to generate test efficiency reports, summarizing the effectiveness of individuals and laboratories to meet established turnaround times. Linked with the Caltrans pavement management system, the MMS will allow researchers to study the relationships between initial materials properties and ultimate performance. This will have a direct feedback benefit, allowing performance to be optimized through adjustments to specifications
and construction practices.
Caltrans expends nearly $640 million annually in its capital program on Tier 3 and Tier 4 materials and 800 PY s ($52 million) to test and inspect these materials. Many of the innovative practices would shift a significant portion of this testing and inspection workload to contractors and producers, thus freeing limited in-house resources to focus on the most critical materials. For Caltrans, this is particularly important because its massive toll bridge earthquake retrofit program has created a considerable increase in testing and inspection workload for Tier 1 materials. Adoption of innovative QA practices will allow the department to divert as much as 90% of its Tier 3 and Tier 4 testing and inspection resources to Tier 1 materials. Caltrans could expand its testing and inspection capacity to meet the increased workload posed by the retrofit program by shifting a portion of its Tier 3 and Tier 4 workload to the private sector and paying for these services through increased unit bid costs.
An analysis of AC QC/QA projects bid over the 3-year period ending January 1, 2003, illustrates how this shift is taking place. The Caltrans QC/QA specification requires the contractor to provide the QC test results used for acceptance determination and pay adjustment calculation and requires the state to verify these results by testing independently obtained samples at roughly 10% the normal rate. Approximately