Proposed AASHTO Practice and Tests for Process Control and Product Acceptance of Asphalt-Treated Cold Recycled Pavements (2021) / Chapter Skim
Currently Skimming:
Chapter 2 - Research Approach
Chapter 2 - Research Approach
Pages 7-24
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 7... ...
conducted with test slabs of recycled materials fabricated in the laboratory using materials sampled from recycling proj- 2.1.1 Specification Review ects in the United States and Canada. Phase III, a field-based experiment, was conducted where the most representative The standard specifications and special provisions for tests identified in Phase II were used to assess the early-age asphalt-based CIR, CCPR, or FDR from U.S.
|
From page 8... ...
tics by practitioners (e.g., time taken to perform the test, equipment required) , 2.2 Phase II -- Laboratory Testing • Potential field projects that could be used in Phase III of the study for evaluating the testing procedures developed Using the information collected during the literature in Phase II, and review and stakeholder survey, the research team developed • Recommended improvements to existing tests from a laboratory experiment conducted in Phase II of this study.
|
From page 9... ...
Industry and tests that could be conducted easily, quickly, and inexpenagency partners assisted the research team with identifying sively in a field setting and could quantify material property relevant projects, obtaining the mix designs, and shipping differences resulting from changes in curing time, type of approximately 500 lb to 600 lb of loose materials from each stabilizing/recycling agent, and presence of active filler. project.
|
From page 10... ...
64-22 binder already stiffness of a recycled material, rather than each possible com- available in the laboratory was included. To help develop bination of recycling process, stabilizing/recycling agents, a more complete matrix of material types, 24 and 48 5-gal chemical additives/active fillers, geographic location, and RAP buckets of loose material were sampled from two ongoing type being tested, an experimental design could be developed research studies in California and Virginia, respectively.
|
From page 11... ...
The slab specimens were prepared using an IPC Global/ 4. Calculate water to reach an optimum moisture content of Controls Group Advanced Asphalt Slab Roller Compactor.
|
From page 12... ...
These tests, listed in Table 2.2, were grouped into the following material property catego ries: density, stiffness, penetration resistance, deformation Table 2.2. List of properties and tests for Phase II testing. Property Suggested Test or Device Density Mass of dry material divided by slab volume Stiffness Soil stiffness gauge Lightweight deflectometer Penetration resistance Dynamic cone penetrometer Deformation resistance Marshall hammer Shear resistance Long-pin shear test*
|
From page 13... ...
However, the purpose of the Phase II laboratory testing was to assess the Figure 2.5. LWD test conducted at the center of response of the various test methods with respect to changes a test slab. in material properties in the laboratory.
|
From page 14... ...
Testing was conducted at 2 and 72 hours after compaction using the same slabs used during stiffness testing, and again at 1 and 24 hours after compaction for the same test slabs used during raveling testing (discussed in the following sections)
|
From page 15... ...
shear test in that the upper assembly of a DCP was used to The raveling resistance of the recycled materials was drive the raveling test fixture into the test slab, as shown in assessed using a modified version of the shear test fixture. Figure 2.12.
|
From page 16... ...
These tests included penetration resistance tests using a rapid compaction control device, a stiffness test using a Clegg hammer, stiffness assessment using an ultrasonic pulse velocity and portable seismic pavement analyzer, a raveling/abrasion test using the Wet Track Abrasion Test and cohesion testing (ASTM D3910) , and a cohesion test with a field-portable pneumatic cohesion tester (based on the ASTM D3910 cohesion test)
|
From page 17... ...
shear test slabs. One or two replicate slabs were prepared Stiffness and shear resistance tests were conducted on the from each source project.
|
From page 18... ...
2.4 Repeatability and Reproducibility of Field Raveling and Shear Tests 2.3.2 Field Project Summary A preliminary evaluation of repeatability and repro Table 2.3 shows a summary of the Phase III field projects. ducibility of the raveling and shear tests developed in this All testing was done during the 2019 construction season.
|
From page 19... ...
Figure 2.17. Project locations for Phase III. Table 2.3. Phase III project summary.
|
From page 20... ...
Total number of sections 14 Total number of test blocks 51 Total number of unique process/material combinations 8 Notes: F-C = foam plus cement; F-N = foam, no cement; E-C = emulsion Table 2.4. Phase III project testing details. plus cement; E-N = emulsion, no cement.
|
From page 21... ...
Tip Angle, ° Angular Rate, °/sec Tip Dullness Outer Pin Diameter, in. Specimen 1 +1 +1 +1 −1 −1 Specimen 2 −1 +1 +1 +1 +1 Specimen 3 −1 −1 +1 +1 −1 Specimen 4 +1 −1 −1 +1 +1 Specimen 5 −1 +1 −1 −1 +1 Specimen 6 +1 −1 +1 −1 +1 Specimen 7 +1 +1 −1 +1 −1 Specimen 8 −1 −1 −1 −1 −1 Table 2.9. Shear test experimental design for ruggedness evaluation.
|
From page 22... ...
× 3.5 in. Test slabs for raveling tests were method (e.g., from a ruggedness study)
|
From page 23... ...
Table 2.11. Actual ILS test sections. Test Section Direction 1 2 3 4 5 6 7 8 Westbound – – – – – – CCPR F-C – Eastbound FDR E-C – CIR F-C CIR E-N CCPR E-N – CCPR F-C – Notes: CIR E-N = cold in-place recycling, emulsion, no cement; CIR F-C = cold in-place recycling, foam plus cement; CCPR F-C = cold central-plant recycling, foam plus cement; CCPR E-N = cold central-plant recycling, emulsion, no cement; FDR E-C = full-depth reclamation, emulsion plus cement.
|
From page 24... ...
Three replicate considered it a sixth material type. LWD, SSG, DCP, shear, and raveling tests were performed The research team established three adjacent test blocks in each test block as soon as the test section was available in a random location along the length of the test section following compaction.
|
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.