Asphalt Mix Basics - Florida Department of Transportation
Transcript Asphalt Mix Basics - Florida Department of Transportation
95% in excellent to good condition.
FDOT: 12,088 centerline miles, 42,633 lane
Statewide: 121,446 centerline miles, 267,793
FDOT: 10% centerline miles, 16% lane miles.
FDOT carries 54% of all traffic in state.
Deficient Pavements (%)
Section 334.046 of Florida Statutes: “Ensuring that 80% of
the pavement on the SHS meets Department Standards”
% of SHS Deficient
334 Superpave Asphalt Concrete
Variable Thickness Overbuild
SP 9.5 minimum thickness = 3/8 inch
SP 12.5 minimum thickness = 3/4 inch
Roadway Sampling and Testing
Allows engineer to move core location for safety reasons
Individual Test Tolerance for QC Testing
ONE average sublot density MPR failure terminates the
LOT – course or fine.
Removal of mandatory requirement to remove material
if delineation occurs.
300 Prime and Tack Coats
Minimum tack rate for newly constructed asphalt
layers = 0.03 gal/sy
330 Construction Requirements
Straightedge Exceptions – clarification of intersection
Friction Course - Address all deficiencies in either
wheel path that exceed 3/16 inch.
338 Value Added pavements
Bleeding area description clarified to an “area 10 sf.”
Replacement of RA binders with PG binders.
300 Prime and Tack Coats
NTSS-1hm now allowed for use as prime coat.
Tack all asphalt layers prior to constructing next
330 General Construction
Clarification to Table 330-1 – Ambient Air
Deleted requirement for RSE QC testing on friction course
on jobs w/ laser acceptance
Clarified straightedge deficiency corrections
Changed minimum overbuild thickness for
SP-12.5 to ½”
Deleted RA Grades and references to
Replaced Pavement Composition Reports
with Pavement Coring Reports
No more gradation and binder content
Do not perform density testing in areas less
than 50 tons within a sublot
Change in density tonnage for pay factor
Deleted Ninitial mix design requirement
New RAP Binder Table
0 - 15
16 - 30
Concept: Focus on performance rather than
prescriptive construction requirements
Eliminate all specification requirements for
tacking (materials, application rates,
methods of control, etc.) for all dense graded
Eliminate all FDOT pre-testing of tack coat
Require Contractor to identify in QC Plan the
methods to be used for bonding pavements
Provision for bond strength testing if
determined necessary by the Engineer
Based on visual inspection
Informational bond strength testing available
Contact Sungho Kim
352-955-6314 / [email protected]
Will be used on trial project:
SR-26 Alachua County
Multiple test sections:
SR-2 Baker County
US-90 Gadsden County
ARMI = Poorest performance for rutting and
cracking on test sections
UF Study = Bad
Will be removed as a standard design alternative
Current research being done to find appropriate
replacement for ARMI
Maintain use of current quantity of GTR.
Minimum of 7% GTR
Optional addition of SBS polymer.
Replace ARB-5 and ARB-12 with PG 76-22R.
Meet the criteria of a performance graded
Separation and Workability
July 2013 Specification Changes
Planned test section on US-98 in Gulf County (2012) to
1/2” and 3/4” HMA overlays with FC-4.75 mix.
1” HMA overlay with FC-9.5 mm mix.
Bonded friction course.
Mill and resurface 1” FC-9.5.
Mill and resurface 1.5” FC-12.5.
Located in Auburn, AL.
(2 ea x 200’)
RAP versus RAS
PG 76-22 (SBS)
versus PG 76-22R
1.7 mile total length of track
Thick polymer modified tack coats.
Two types (emulsified - spray paver) or non-emulsified.
Surface of Mix
Direction of Paving
Loads at 8 mph.
Can change wheel type (single or dual).
Purchased in S. Africa.
Current Round of
PG 76-22R Sections
4.75 mm mix
Prime vs. no prime vs.
Effects of increased
RAP in dense graded
friction courses (UF)
FC-5 durability study
Sampling at the Paver
Data Analysis (NCAT)
CPF Analysis (FDOT)
End of Project CPF
QC Adjusted Lot CPF
F & t Statistical
New LIMS system