Details:

Creators:
Scholz, Todd V. ; Samoo, Faisal
Scholz, Todd V. ; Samoo, Faisal Less -
Corporate Creators:
Kiewit Center for Infrastructure and Transportation
Subject/TRT Terms:
[+]
Asphalt Emulsion Mixtures Asphalt Mixtures Binders Binders (Materials) Calibration Hot Mix Asphalt Ignition Nuclear Density Gages Pavements, Asphalt--Recycling Quality Assurance Quality Control 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
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
Download URL:
https://rosap.ntl.bts.gov/view/dot/25722/dot_25722_DS1.pdf
File Type:

Supporting Files

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