Evaluating Applications of Field Spectroscopy Devices to Fingerprint Commonly Used Construction Materials (Phase IV–Implementation) (2014) / Chapter Skim
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CHAPTER 3 Findings and Applications Identification of Participating Agencies The pre-implementation phase of this project started with identifying a group of participating DOTs that would be willing to provide their input on the following three draft AASHTO standard practices that were proposed in the earlier phase of the project (Zofka et al., 2013)
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admixture would not serve any additional purpose. Because of this limited interest, the team later had difficulty identifying suitable projects on which to conduct the field testing.
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Revision of Proposed AASHTO Standards The next three subsections provide brief descriptions of the tests, the nature of agencies' comments, and implemented revisions for each draft AASHTO standard separately. A full description of the standards can be found in Appendix A, whereas the background on methods of spectroscopic evaluation of materials can be found elsewhere (Zofka et al.
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of XRF analyzers and related materials was included as an appendix. The quality control sections were updated with specific instructions for instrument calibration and periodic standardization.
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was sufficient to confirm very high repeatability of the method, as shown in Figure 3.1. This way a signature spectrum was determined for each sample listed in Table 3.2, shown in Appendix C
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Figure 3.1. ATR absorbance spectra of the CTDOT chemical admixtures.
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The effect of dilution on the XRF signal of latex paints was determined by testing samples corresponding to different paint-to-water ratios (Figure 3.2)
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0.59 mm and 0.297 mm) was tested from each sieved sample.
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Table 3.5 Summary of Maine DOT RAP Sample Information RAP Stockpile ID Nearby Location Latitude, °N Longitude, °W RAP Classification Passing #200 Standard Deviation in Asphalt Content LAN-HE13-CRQ Hampden, Maine 44.785 –68.8319 Pure aggregate N/A N/A LAN-SM13-II Smyrna, Maine 46.1301 –68.1579 Class II ≤10% ≤0.5 PII-WE13-I Wells, Maine Wells, Maine Wells, Maine Class I ≤8% ≤0.3 PII-HE13-I Hampden, Maine 44.7783 –68.8395 Class I ≤8% ≤0.3 PII-FF13-II Fairfield, Maine 44.5908 –69.6134 Class II ≤10% ≤0.5 LAN-WB13-II Wetsbrook, Maine 43.7321 –70.3527 Class II ≤10% ≤0.5 PII-PNH13-I Portsmouth, N.H. 43.0466 –70.7794 Class I ≤8% ≤0.3 CMP-SC13-III Dayton, Maine 43.5294 –70.5931 Class III >10% N/A PII-WB13-I Wetsbrook, Maine 43.6742 –70.3320 Class I ≤8% ≤0.3 LAN-PI13-II Presque Isle, Maine 46.7359 –67.9614 Class II ≤10% ≤0.5 PII-PO3-I Poland, Maine 44.0165 –70.3491 Class I ≤8% ≤0.3 LAN-WA13-III Washington, Maine 44.2226 –69.3853 Class III >10% N/A To obtain an infrared (IR)
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carbonyl and aromatic groups with storage time. The signal from the water presence at around 3350 cm–1 indicates higher moisture content for the 5-year-old stockpile.
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Figure 3.4. Effect of location on RAP oxidation in Maine.
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XRF of Bridge and Traffic Paints in Maine In situ XRF testing was performed in collaboration with the Maine Department of Transportation. The first field test was conducted on a bridge overpassing I-95 one mi north of Exit 174.
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Collectively, these results show that XRF is effective for field testing the Ti content of bridge paint, in that in situ measurements closely matched lab measurements. The wide variation exhibited by other elements is suggestive of potential for interference effects depending on the substrate.
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for quality control applications. In Connecticut, interest was expressed in linking XRF data to thickness measurements and other techniques for the purposes of enhancing quality control and optimizing the paint application procedure.
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0.46) linear trend of increase in oxidation with pavement age.
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