Evaluating Applications of Field Spectroscopy Devices to Fingerprint Commonly Used Construction Materials (2013) / Chapter Skim
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10 Review of Spectroscopic Applications to Construction Materials This chapter presents the major findings from the literature search on the state-of-the-art theory and practice for fingerprinting the most common materials used in highway construction. The full literature review of the principles of several spectroscopic techniques and a discussion on their applicability to testing highway construction materials is provided in Appendix E
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11 Chromatographic methods physically separate the components of a mixture and distribute them between two phases. One phase remains stationary (a solid, a gel, or a liquid solvent)
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12 of NMR equipment. Another important observation from the literature review is that researchers have been more successful in the qualitative rather than the quantitative analysis of chemicals compounds, because the quantification of components in construction materials requires the development of calibration curves using pure compounds.
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13 properties of both asphaltic materials and portland cement. XRD has been traditionally used to investigate the portland cement composition rather than for the analysis of asphalt components.
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14 lists the spectroscopic devices chosen for the proof-of-concept experiments in Phase 2. Both portable and stationary equipment were included in the experimental protocol to compare detection limits, accuracy, and precision.
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15 field tests. The overall scores varied from 1.0 (Texas)
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16 signature spectra of individual material components (Parts A and B) were obtained (see Appendix I)
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17 Waterborne Paints Waterborne traffic paints typically have several components: polymer binder, pigment, filler, water, organic solvent, and other minor additives. Pigments often consist of transition metal elements, such as Ti, Cr, and Fe.
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18 as described in the section on field verification of laboratory results. Polymer Additives to Asphalt Polymer additives have been increasingly used to improve asphalt durability and resistance to rutting.
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19 (most likely because of their extremely low concentration in the mixtures)
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20 the IR absorption peaks at 1,662, 1,608, and 1,580 cm-1. Figure 3.7 tracks changes in the ATR FTIR spectrum of Ultrabond 1100 adhesive after 10-min curing.
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21 samples are compared in Figure 3.8. The waterborne vinyl acrylate structure of a liquid sample from a tank can be easily identified by the medium-wide water-associated (~3,400, ~3,250, and ~1,640 cm-1)
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22 1,455, and 1,374 cm-1) associated with hydrocarbon resin and aliphatic naphtha components of TAMMSCURE (see MSDS)
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23 0.7 wt% of the batch weight for ADVA 190 and Accelguard 80, respectively) as compared with AIR 200 and Eucon Retarder 75 with 0.07 and 0.13 wt%, respectively (see Table 3.5)
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24 Polymers in Asphalt Products The major objective for spectroscopic evaluation of polymermodified asphalt products was identification of polymer type and, if possible, determination of polymer content in asphalt binders, emulsions, and HMA mixtures. Two SBbased polymers -- Kraton SBS and BASF's Butonal NX1138 -- were used in this study to produce polymer-modified binders in the laboratory.
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25 ing vibrations of aliphatic hydrocarbons in asphalt binder. Last, one can notice that spectra of both stirred emulsion and its binder-segregated portion show highly intensive absorbance at ~1,740 and ~1,250 cm-1, which indicates presence of carboxylate emulsifier in the polymer-modified emulsions.
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26 summarizes the asphalt binders and the modifiers used for aging experiments. The PG of asphalt binders ranged from PG 52-34 to PG 64-28.
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27 extinction coefficients (or coefficient of absorptivity, e) for polystyrene and polybutadiene were determined as a ratio of IR absorbance value, A, at ~965 and ~700 cm-1, correspondingly, over the polymer content, c, multiplied by the IR light path length, l, as shown in Equation 3.1.
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28 and A700 peaks be interchangeably used for quantification of SB polymers in PMBs. When the team studied the effect of oxidative hardening on PMBs, no noticeable change in polymer content resulting from oxidation was found for PMBs with the SB content up to 3.5 wt% (see Figure K.5 in Appendix K)
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29 presence of SBS. It should be noted that polybutadiene peak at 967 cm-1 is likely to be obscured by the strong and wide band centered around 1,000 cm-1 that is associated with the silicate component of the aggregates.
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30 was probed by pipetting two to three drops on the ATR sampling plate. The ATR FTIR spectra of the sample were collected twice: immediately and within 1 to 2 min from the moment of placement.
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31 binder and (2) loose HMA samples modified by up to 80 wt% RAP.
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32 shown in Figure 3.23. The individual integrated areas of the oxidized functionalities were then normalized to the sum of all band areas to calculate individual oxidation indices (1)
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34 repeatability concerned the variation in measurements taken by a single operator or instrument on the same item and under the same conditions. The reproducibility of test results was judged by the level of variability in the results measured by independent operators on the same equipment.
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35 signal intensity. This observation was reflected in developing a test procedure for pavement markings by recommending of the use of pressure applicator with solid samples as a general rule for ATR testing.
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36 bands for a given material at the same wavelength (see Figures P.1 and P.2 in Appendix P)
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37 Table 3.9. Summary of Portable Equipment Evaluation Featurea Target Value FTIR Raman XRF XRD Accuracy Minimum 1% <0.5% <2% <1% <1% Goal <0.5% Duration of measurement Maximum 1 h ∼1 min ∼1 min 6–12 min 15 min Goal ∼5 min Effort involved Maximum 1 person 1 person 1 person 1 person 1 person Goal 1 person Amount of prior training Maximum 1 day 1 h 1 h 1 h 1 h Goal 0.5 day Reliability Minimum Depends on material (90%)
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38 of first evaluating those contributions and determining the appropriate background removal techniques to yield spectra consistent with those of controlled laboratory conditions. Summary of Field Results A summary of the field results follows.
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