Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results (2021) / Chapter Skim
Currently Skimming:
Pages 60-76
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 60... ...
60 Research Approach Overview Alternatives to loose mixture aging to obtain inputs for the PAM were investigated; these alternatives include aging binders in both an RTFO and PAV before testing as well as using the PG to derive approximations. Obtaining material-specific kinetics parameters [i.e., log |G*
|
From page 61... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 61 40-hour PAV aging. The kinetics of the loose mixture aging of each mixture were compared against the kinetics obtained from RTFO and PAV aging.
|
From page 62... ...
62 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results Microextraction and Recovery Microextraction and recovery of the asphalt binder from the asphalt mixtures and field cores were undertaken following the procedure proposed by Farrar et al.
|
From page 63... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 63 the second was to establish an empirical relationship between the binder PG and the materialspecific parameters. The method presented here to equate loose mixture kinetics and binder kinetics obtained from RTFO and PAV tests is empirical in nature.
|
From page 64... ...
64 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results (loose mixture aging) conditions and log |G*
|
From page 65... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 65 The log |G* | beyond 6 days of aging was observed to be proportional to log |G*
|
From page 66... ...
66 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results Similarly, 40-hour PAV |G* | can be considered equivalent to 6-day loose mixture aging |G*
|
From page 67... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 67 provide an adequate estimation of the material-specific kinetics parameters that yields longterm aged log |G* | values close to those measured from field cores.
|
From page 68... ...
68 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results Estimation of the Pavement Aging Model Parameters for RAP Mixtures Using Virgin Binder Properties For the mixtures that contain RAP, obtaining the material-specific kinetics parameters becomes more complex because of the presence of both virgin and RAP binder and the degree of blending between the two. The blending of the virgin and RAP binders is intricate and is governed by the RAP content, RAP properties, virgin binder properties, mixture volumetrics, and other factors.
|
From page 69... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 69 The RAP kinetics parameters can then be combined with the virgin kinetics parameters to estimate the RAP-containing mixture kinetics parameters. Estimation of the Material-Specific Parameters of RAP-Containing Mixtures Given Individual Virgin and RAP Parameters For virgin binder, the material-specific parameters, log |G*
|
From page 70... ...
70 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results weighted average of the virgin binder's reactive material and 100% RAP-extracted binder's reactive material, as shown in Equation (32)
|
From page 71... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 71 HPG reported in the literature (shown in Table 13 and Figure 48)
|
From page 72... ...
72 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results 2 Sources: PG 82, PG 88 3 Sources: PG 70, PG 76, PG 88 4 Sources: PG 82 2 Sources: PG 94, PG 100 20 Sources: AVG PG 90 28 Sources: 1 : PG 82 10 : PG 88 11 : PG 94 6 : PG >100 AVG: PG 94 2 Sources: PG 86, PG 90 3 Sources: PG 82, PG 88 5 Sources: PG 112 - PG 130 1 Source: PG 88 1 Source: PG 82 3 Sources: PG 82, PG 76 1 Source: PG 702 Sources: PG 82, PG 88 Figure 48. Distribution of RAP sources from literature with their HPG across the map of the United States.
|
From page 73... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 73 Virgin Binder HPG 58 (b) Virgin Binder HPG 64 (c)
|
From page 74... ...
74 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results Virgin Binder HPG 70 (d) Virgin Binder HPG 76 (e)
|
From page 75... ...
Development of Procedures to Estimate the PAM Inputs Using Standard Binder Aging Methods and PG 75 A user would thus refer to Figure 49 to determine the estimated HPG of the RAP, knowing the virgin binder HPG that is commonly used in the area of interest. To be conservative, the HPG of the RAP should be rounded up to the higher end of the scale shown in the legends presented in Figure 49 or even bumped up another grade depending on individual local experience in handling RAP in the different states.
|
From page 76... ...
76 Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction: Phase III Results Summary The PAM requires two primary material inputs, log |G* | at short-term aging and M, and the pavement temperature history.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.