Details:

Creators:
Scholz, Todd V. ; Samoo, Faisal ;
Scholz, Todd V. ; Samoo, Faisal ; Less -
Corporate Creators:
Kiewit Center for Infrastructure and Transportation ;
Subject/TRT Terms:
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Asphalt Emulsion Mixtures
Binders (Materials)
Calibration
Pavements, Asphalt--Recycling
Quality Assurance
Quality Control
Asphalt Mixtures
Binders
Hot Mix Paving Mixtures
Ignition
Nuclear Density Gages
Recycled Materials

Publication/ Report Number:
FHWA-OR-RD-13-05 ;
Resource Type:
Tech Report ;
Geographical Coverage:
Oregon ;
Edition:
Final report.
Corporate Publisher:
Oregon. Dept. of Transportation. Research Section ;
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and Performance
Abstract:
This study investigated several characteristics of laboratory-fabricated and plant-produced hot-mix asphalt mixtures containing various proportions of RAP and RAS with the principal objectives of developing a procedure for selecting the virgin binder grade used in such mixtures as well as a procedure for determining ignition oven calibration factors for mixtures containing these materials. Other objectives included developing recommendations for procedures to effectively and efficiently recover asphalt binder from RAS, batch and mix reclaimed materials with virgin materials, and for quality control and quality assurance testing. The blending chart analysis procedure described in AASHTO PP 53 for selecting a virgin binder grade was selected as a starting point for evaluation purposes, but the attempt to validate the procedure was unsuccessful. Consequently, an alternate approach was recommended for further investigation. ODOT’s current method for determining ignition oven calibration factors (TM 323) was evaluated using both laboratoryprepared and plant-produced mixtures. Findings from this evaluation provided strong evidence to suggest procedural changes to the current method are unnecessary. Further, modification of ODOT’s current independent assurance parameter for asphalt binder content is not justified at this time. However, changes to the language in the test method to include RAS are needed and recommendations for these are provided. Selection of procedures for extracting and recovering binder from RAS was accomplished through a literature search. Selection of procedures for QC and QA was accomplished in the same manner. However, detailed procedures for fabricating laboratory specimens containing RAS were not found. Consequently, taking into consideration existing procedures, new procedures were developed for batching and mixing specimens containing RAP, RAS, or combinations of RAP and RAS. The applicability of using of nuclear density gauges to determine in-place density of mixtures containing RAS was also evaluated. Assessment was based on variability of density measurements obtained from nuclear gauges and from pavement cores. Findings indicated no difference in the quality of measurements made on mixtures containing RAP and RAS versus those containing only RAP.
Format:
PDF ;
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:454b86578ea67ff231539e7b0e27f0613ca6df665608f34d646d2d91bd0be0de
File Type:

Supporting Files

• No Additional Files

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