State University System of Florida
Florida Center for Solid and Hazardous Waste Management
QUARTERLY PROGRESS REPORT
September 28, 2005
PROJECT TITLE: Developing Re-Use Applications and Improving the Economic
Benefits of Florida’s Waste Materials
PRINCIPAL INVESTIGATOR: Paul J. Cosentino, Ph.D., P.E.
AFFILIATION:
Florida Institute of Technology, Department of Civil Engineering
COMPLETION DATE: December 31, 2005 based on requested no cost extension 1
________________________________________________________________________
The objective of this 12-month research project is to identify Florida’s candidate waste
materials and to improve their engineering performance and subsequent re-use by adding
commonly used fill materials such as sand. During the project the best candidate
materials will be selected and subjected to fundamental geotechnical testing. RAP and
concrete rubble, which are known to pose minimal environmental concerns, will be the
focus of the group. At the completion of the project, specifications describing how the
waste materials could be used will be compiled.
Work Completed to Date
A project web site was developed at: http://www.civil.fit.edu/cosentino_project.html
Task 1-(100%)
Identification of Candidate Waste Materials
Materials being evaluated include recycled asphalt pavement (RAP) and recycled
concrete aggregate (RCA) from construction and demolition debris. RAP has been
classified as “milled RAP” and “crushed RAP”, based on the sample stockpile and
source. A survey of waste material generators was developed and will be posted on the
web site.
Task 2 - (75%)
Sampling of Candidate Waste Materials
Multiple RAP samples and two samples of RCA from the sources within Brevard and
Volusia Counties have been collected.
Task 3 - (60%)
Fundamental Geotechnical Testing of Candidate Waste Materials
Fundamental geotechnical testing, including dry-rodded unit weight, particle size
distribution, moisture-density and bearing strength has been conducted on all RAP
samples and one RCA sample collected thus far.
1 Due to internal budgetary delays associated with Hurricanes Frances and Jeanne a 3-month no cost
extension has been requested.
Task 4 - (50%)
Analysis of Fundamental Geotechnical Testing Results
Test data from the sample tested has been reduced and analyzed to develop base-line
strength-deformation comparison to mixing results. Appendix 1 has comparisons of
particle sizes distribution data and Appendix 2 has a summary of moisture-density,
asphalt-content for RAP and grain size data.
The Appendix 1 figure shows grain size distribution ranges for milled and crushed RAP,
along with RCA plus a comparison to the FDOT specification limits for MSE wall
backfill. Screening of the larger-size particles in the crushed RAP produces the difference
in the initial portions of the two bands. There is also a significant difference between the
bands in the zone from the #10 to the #200 sieves indicating a larger percentage of
smaller particles in the crushed RAP. The fines content is slightly higher in the crushed
RAP.
According to the American Association for State Highway and Transportation Officials
(AASHTO) and Unified Soil Classification System (USCS), the two materials classify
differently. The crushed RAP classified as an A-1-b soil as per AASHTO and SP
according to USCS, while the milled RAP classified as A-1-a and GW respectively.
When mixed with A-3 sand, the crushed RAP mixes maintained their classification, while
the milled RAP sample shifted to become A-1-b and SP.
RCA is a courser grained product than either RAP products. According to the USCS it is
a gravel (G) that ranges from well graded (W) on the finer edge of the range to a poorly
graded (P) product on the coarser edge of the range. According to the AASHTO
classification system it is an A-1-a.
The Appendix 2 Table indicates that RCA has a much higher optimum moisture content
that either RAP products. The maximum density however, matches that of the crushed
RAP. RCA has lass than 1 percent passing the number 200 as do both RAP products,
while the D10 which is used in evaluation of permeability is similar to the RAP products.
Task 5 - (50%)
Waste-Soil Mixing Program
Mixing of RAP with various fill materials, including AASHTO A-2-4 and A-3 sands has
been conducted. In addition to 100% RAP and 100% RCA, mixtures with 80% RAP,
60% RAP, and 70% RCA have been identified for geotechnical testing.
Task 6 - (40%)
Waste-Soil Fundamental Geotechnical Testing Program
Geotechnical testing of mixes with 80% and 60% RAP has been conducted in parallel
with control samples of 100% A-3 and 100% A-2-4 sands.
Task 7 - (50%)
Analysis of Mixing Results
Geotechnical testing results have been analyzed for the samples tested, including the
100%, 80%, and 60% RAP as well as control materials. RAP, RCA, and RAP-Soil
mixtures have desirable engineering characteristics for use as fill in nonstructural areas
within the highway. It is expected that RCA-Soil mixtures will also have desirable
engineering characteristics.
Task 8 - (25%)
Economic Impact of Re-Usable Materials
Benefit/Cost analysis of the chosen waste materials has begun. The survey developed and
distributed to facilities processing RAP and RCA includes questions specifically
concerned with costs. Survey data was collected via phone-calls, e-mails, and site visits.
Data is being based on stockpiled quantities, material supply, and local regulations.
Task 9 – (50%)
Reporting, TAG Meetings and Specification Development
The Second Quarterly Report has been submitted and most of the TAG members have
been contacted either through meetings or over the phone.
Time Spent by PI
During the past five months of the project, the PI spent 20 hours on project-related tasks.
Work to be Completed Next Quarter
Task 1
Identification of Candidate Waste Materials
Task 1 is complete.
Task 2
Sampling of Candidate Waste Materials
Several sources of candidate waste materials from throughout Florida are currently being
explored for sampling and testing.
Task 3
Fundamental Geotechnical Testing of Candidate Waste Materials
Additional RAP as well as RCA samples will be tested.
Task 4
Analysis of Fundamental Geotechnical Testing Results
Further testing of RAP as well as RCA samples will be conducted and analyzed.
Task 5
Waste-Soil Mixing Program
Further mixing analysis of RAP and RCA with other fill materials must be identified for
additional testing.
Task 6
Waste-Soil Fundamental Geotechnical Testing Program
Further testing of 70% RCA samples will be conducted.
Task 7
Analysis of Mixing Results
Analysis and comparison between mixes and various waste materials must be completed
parallel to further geotechnical testing. Creep or long term deformation of RAP is a
engineering concern that must be carefully documented.
Task 8
Economic Impact of Re-Usable Materials
Additional survey responses will be collected and analyzed. Data will be analyzed to
identify economical reuse applications, based on stockpiled quantities, various processes
used to size these waste materials, material supply and local regulations.
Task 9
Reporting, TAG Meetings and Specification Development
The second TAG Meeting was conducted on August 11, and the third TAG Meeting will
be scheduled for within the next month. Specification development will follow final
analysis of the mixing and geotechnical testing program.
#325
#270
#140
#200
#100
#60
#40
#30
#20
#16
#8
#4
.375"
.75"
1.5"
Appendix 1: Grain Size Distribution Ranges for Recycled Materials
100%
90%
Crushed
RAP
Percent Finer (%)
80%
70%
MSE Wall
Upper Limit
Crushed
RCA
60%
50%
MSE Wall
Lower Limit
40%
30%
20%
Milled
RAP
10%
0%
100
10
1
0.1
Sieve Opening (mm)
Appendix 2: Preliminary Material Properties
Properties
Max Unit Weight
Optimum Moisture Content
Asphalt Content
Passing #200
D10
Crushed RCA
~ 118 pcf
12 - 13%
N/A
0.5% ±0.3%
0.31 ±0.5 mm
Crushed RAP
~ 118 pcf
6–8%
5.0 - 5.2 %
0.8% ±0.3%
0.28 ±0.03 mm
Milled RAP
~ 115 pcf
5.5 %
5.5 - 5.9
0.6% ±0.3%
0.72 ±0.3 mm
0.01