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5C h a p t e r 1 renewal Focus area The U.S. highway system is aging and must be rebuilt while we are driving on it and living next to it. Research in the SHRP 2 Renewal focus area addresses the need to develop a consistent, systematic approach to completing highway projects quickly, with minimal disruption to the community, and producing facilities that are long lasting. Identifying new technologies for locating underground utilities; developing procedures to speed the evaluation of designs and the inspection of construction; and applying new methods and materials for preserving, reha- bilitating, and reconstructing roadways and bridges are among the goals for this focus area. Alternative strategies for contract- ing, financing, and managing projects as well as for mitigating institutional barriers also are part of the emphasis on rapid renewal. The renewal scope applies to all classes of roads. problem Statement Several state departments of transportation have reported qual- ity control issues with many of the materials routinely used in highway construction. Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and Raman spectroscopy are material analysis techniques that have recently been used for transportation materials on a limited basis. They have been employed mostly for âfingerprintingâ or identifying the pres- ence of mixture components, such as deicing compounds or antistripping agents, and occasionally for quantitative analyses, such as polymer content in asphalt and sulfate content of soils. The potential exists for much broader use of these technologies in quality assurance/quality control (QA/QC), for example, in testing cements, paints, thermoplastics, epoxies, asphalt emul- sions, and possibly many others. Using these new technologies, rather than traditional chemical tests, for such applications may allow for faster and accurate QA/QC procedures. Relatively low-cost ($20,000 to $40,000) portable devices have become available for several of these technologies (FTIR, XRF, Raman, and others) that can be employed in the field to test the chemical composition of the delivered materials. These are point-and-shoot applications that could poten- tially be used by field technicians with accuracy similar to that obtained by using traditional stationary laboratory equip- ment. The development of user-friendly software for material analysis and interpretation of results has decreased the need for skilled personnel to use the portable equipment. There- fore, the potential use of portable spectroscopy devices for a wider range of applications has become more practical. research Objectives The primary objective of this project was to identify the most practical applications of portable spectroscopic equipment to a range of materials commonly used in transportation infra- structure. The candidate spectroscopic methods were identi- fied on the basis of a comprehensive review of the related scientific literature and the state-of-practice in spectroscopic equipment. The range of construction materials and desired testing and equipment parameters was identified from a sur- vey of state highway agencies (SHAs). An additional objective was to develop relatively simple spectroscopic testing procedures and protocols that inspec- tors and frontline personnel could use in the field to ensure quality construction. Two potential outcomes for spectro- scopic testing were identified. They were (1) verification of the chemical composition (if provided by the manufacturer) or determination of the signature spectrum for pure materi- als and compounds and their components as supplied by manufacturers, and (2) detection, and, if possible, quantifica- tion of additives and contaminants in a material. Background
