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From page 31... ... 31 Mixture Volumetrics Appendix E provides detailed volumetric properties by field project with a comparison of mixture types for each field project and a separate comparison of specimen types for each field project. Volumetrics provided include total AV for each group of specimens in terms of the average and range, theoretical maximum mixture specific gravity (Gmm) Read the entire page →
From page 32... ... 32 This same conditioning protocol of 2 h at Tc provided the best agreement between MR stiffnesses for LMLC specimens and corresponding PMFC cores for the WMA mixtures from both the Iowa and Texas field projects with only lower MR stiffnesses for the LMLC specimens for WMA Evotherm® 3G with RAP from Iowa and the least difference between these specimen types for WMA foaming from Texas. The conditioning protocols at longer times or higher temperatures resulted in LMLC specimens of more mixtures per field project with MR values that were statistically higher than PMFC cores at construction. Read the entire page →
From page 33... ... 33 For all Texas mixtures, onsite PMLC specimens exhibited equivalent MR stiffnesses to those for PMFC cores at construction. For the Iowa mixtures, this same equivalence was only valid for Iowa WMA Evotherm® 3G with RAP, but the least difference as compared to PMFC cores at construction was shown for onsite PMLC specimens for the other two Iowa mixtures. Read the entire page →
From page 34... ... 34 trends observed for the different performance parameters measured in laboratory tests. The comparisons in test results shown in these summary tables are based on the following for each test parameter: • Wet IDT strength: ANOVA and Tukey's HSD statistical analysis at a 5% significance level. Read the entire page →
From page 35... ... Location Specimen Type Wet IDT TSR Evotherm Sasobit Foaming Evotherm Sasobit Foaming Iowa Cores at construction Fail N/A N/A Cores after winter Fail Cores after summer Onsite PMLC Pass Pass Offsite PMLC Fail LMLC Fail Montana Cores at construction Cores after winter Onsite PMLC Fail Fail Fail Fail Fail Fail Offsite PMLC Pass Pass Pass Texas Cores at construction Fail N/A Fail Fail N/A Cores after summer Onsite PMLC Fail Fail Offsite PMLC Pass Fail Fail LMLC New Mexico Cores at construction Pass N/A N/A Onsite PMLC Offsite PMLC LMLC Fail Fail Fail Key WMA HMA WMA < HMA Table 3-3. Summary trends for IDT strength results. Read the entire page →
From page 36... ... 36 ing mixtures (to 275°F [135°C] Read the entire page →
From page 37... ... 37 decreased performance as compared to the design mixture, yellow shading indicates equivalent performance as compared to the design mixture, and green shading indicates improved performance as compared to the design mixture. For this experiment, LMLC specimens were produced for the Iowa and Texas field projects to evaluate the effect of adding hydrated lime or LAS in terms of wet IDT strength and TSR and wet MR stiffness and MR-ratio. Read the entire page →
From page 38... ... 38 generally able to represent early-life field performance (PMFC cores at construction and after winter at 6 months in service for WMA Evotherm® 3G) ; for two WMAs, the onsite PMLC specimens exhibited lower wet IDT strengths. Read the entire page →
From page 39... ... 39 onsite and offsite PMLC specimens for this parameter. For stripping slope, only one WMA in the Texas field project and both WMAs in the New Mexico field project showed agreement in terms of LMLC specimens representing early-life field performance (PMFC cores at construction) Read the entire page →
From page 40... ... 40 ceptibility evaluated on the basis of wet IDT strength, TSR, wet MR stiffness, MR-ratio, HWTT SIP, and stripping slope after LTOA of compacted specimens at different time periods. Appendix C provides detailed results for the evolution of dry MR stiffness and moisture susceptibility parameters measured in laboratory tests due to field and laboratory aging of age to reach a dry MR stiffness equivalent to that of an HMA control mixture. Read the entire page →
From page 41... ... 41 In addition, onsite PMLC specimens from the Texas field project conditioned 1–2 h at Tc as compared to those conditioned 0–1 h at the same temperature exhibited equivalent dry MR stiffnesses. Equivalent stiffnesses were also shown for onsite PMLC specimens and PMFC cores at construction for the Texas field project, indicating the same level of mixture aging as expected. Read the entire page →
From page 42... ... 42 5 days at 185°F (85°C) by AASHTO R 30 was selected as the third protocol. Read the entire page →
From page 43... ... 43 • HWTT stripping slope: numerical comparison with an allowable difference of 0.2 mm/cycle. Effect of Aging on Mixture Performance Table 3-12 summarizes the comparison of Iowa and Texas mixture performance in IDT strength, MR, and HWTT tests for PMFC cores after field aging in the summer and winter versus those at construction. Read the entire page →
From page 44... ... 44 cantly better performance in the HWTT test. For the two WMAs, PMFC cores after summer at 8 months in service had increased SIP values and decreased stripping slopes as compared to those at construction, indicating improved resistance to moisture susceptibility. Read the entire page →
From page 45... ... 45 (mixtures and LTOA protocols) , LMLC specimens with laboratory LTOA protocols had higher SIP and lower stripping slope than those without LTOA. Read the entire page →
From page 46... ... 46 these comparisons, and red shading indicates that LMLC specimens exhibited increased performance for the same comparisons. For the Iowa field project with limited data available, LTOA protocol of 16 weeks at 140°F (60°C) Read the entire page →
From page 47... ... 47 Comparison of WMA vs. HMA Table 3-18 summarizes the comparison of WMA and HMA with different field aging times and laboratory LTOA protocols in the Iowa and Texas field projects. Read the entire page →
From page 48... ... 48 lent performance was exhibited by LMLC specimens of both WMAs in terms of wet and dry IDT strength, SIP, and stripping slope. Mixed results in terms of improved WMA performance were shown for these two longer laboratory LTOA protocols for wet and dry MR stiffness, MR-ratio, and TSR. Read the entire page →
From page 49... ... 49 In general, the initial performance of HMA PMFC cores and LMLC specimens without field and laboratory aging was better than the performance of the WMA mixtures. However, the dif- ference was reduced with field aging and laboratory LTOA. Read the entire page →
From page 50... ... 50 LMLC LTOA 16 weeks @ 60°C IDT Dry IDT Strength N/A N/A Wet IDT Strength E S TSR E F MR Dry MR Wet MR MR-ratio HWTT SIP N/A Stripping Slope LMLC LTOA 5 days @ 85°C IDT Dry IDT Strength N/A Wet IDT Strength TSR MR Dry MR Wet MR MR-ratio E F E F HWTT SIP Stripping Slope Key Decreased Performance Equivalent or Increased Performance Note: E: Iowa WMA Evotherm® 3G with RAP or Texas WMA Evotherm DAT™ or New Mexico WMA Evotherm® 3G with RAP; S: Iowa WMA Sasobit® with RAP; F: Texas WMA foaming or New Mexico WMA foaming with RAP. Aging Stage Test Parameters Iowa WMA vs. Read the entire page →

From page 31...

... 31 Mixture Volumetrics Appendix E provides detailed volumetric properties by field project with a comparison of mixture types for each field project and a separate comparison of specimen types for each field project. Volumetrics provided include total AV for each group of specimens in terms of the average and range, theoretical maximum mixture specific gravity (Gmm)