Pavement Warranties Yield Innovation, Quality
Faced with staff and budget shrinkages and the need to
increase pavement quality and life-cycle performance, some State highway
agencies are finding that pavement warranties offer an alternative way
to assure performance. These warranties guarantee the integrity of the
product and the contractor's responsibility to repair or replace defects
for a defined period.
The Indiana Department of Transportation (INDOT) started
using warranties on asphalt pavements 7 years ago. The agency's goal
was to encourage contractor innovation and at the same time compensate
for a decrease in manpower for inspection and oversight. "We wanted
to be able to do more with fewer people," says Dave Andrewski of
INDOT. Indiana awards about two or three warrantied projects a year,
with the warranties good for 5 years. The warranties are placed on very
high traffic volume projects in conjunction with time incentives. This
is done to ensure that the fast pace of construction that time incentives
encourage still produces a high quality project for INDOT. The effort
started with asphalt pavements but expanded last year to concrete with
the construction of a warrantied pavement on I-65 in the southern part
of the State. The warranty specifications were developed in concert
with industry. Indiana is pleased with the results to date. "The
projects are built faster and we get quality work and very smooth pavements,"
says Andrewski.
At the end of the 5-year warranty period, threshold values
for International Roughness Index, surface deformation (rutting for
asphalt pavements/scaling for concrete pavements), transverse cracking,
longitudinal cracking, friction number, and joint sealant condition
(for concrete pavement only) are measured. If the pavement meets those
values at the 5-year mark, then INDOT is confident based on historical
data that the pavement will be serviceable through its design life.
To date, two asphalt pavement contracts have reached the 5-year mark
and both have been accepted.
The Michigan Department of Transportation (DOT) started
using warranties in 1996. While the agency started with materials and
workmanship warranties, it has since expanded the warranty program to
include performance warranties also. Performance warranties allow the
contractor more flexibility in terms of materials selection, workmanship
methods, and design decisions. "We started exploring warranties
as a way to reduce oversight but still ensure that contractors are delivering
the high quality product we need. It's also about getting contractors
to take a long-term interest in pavement performance," says Steve
Bower of Michigan DOT. "We're trying to get the contractors to
have a high level of self awareness with regard to construction quality.
It raises awareness about how workmanship and materials decisions can
affect long-term pavement performance." From 1996-2002, the State
let 473 preventive maintenance projects that had warranties and 131
rehabilitation projects. More than 90 percent of projects in the agency's
2002 Capital Preventive Maintenance (CPM) Program were warrantied, while
more than 50 percent of 2002 reconstruction and rehabilitation projects
included a pavement warranty.
CPM pavement warranties are for a 3-year duration and
include treatments such as thin asphalt overlays, concrete patching,
chip seals, and microsurfacing. Rehabilitation and reconstruction warranties
are for a 5-year duration and include fixes such as new concrete and
asphalt construction, hot-mix asphalt (HMA) overlays on repaired pavement,
and HMA overlays on rubblized concrete pavement.
In December 2002, the DOT began work on a 19.3-km (12-mi)
project on the M-6 Freeway Bypass in Grand Rapids that will have a 7-year
performance warranty. "The contractor will have additional flexibility
with the mix design, more than would usually be given under the standard
QC/QA approach," says Bower. Two more performance warranty projects
will be let in March 2003, using the same specifications.
Michigan reports that its construction oversight costs
have dropped since it started using warranties. The DOT has not yet
seen a longer service life for pavements but it has observed more innovation
on the part of contractors. Lessons learned have included the need to
have a good pavement management system (PMS) in place. A good PMS is
necessary in order to have the comprehensive pavement performance data
that is needed for developing pavement performance measures and thresholds.
Bower notes that the agency picked thresholds and performance levels
that are attainable based on pavement management data from past projects.
"It is imperative that you manage the risk for contractors or it
will translate into higher bid prices," says Bower.
For more information on Indiana's warranty use, contact
Dave Andrewski at INDOT, 317-610-7251, x. 212 (email: dandrewski@indot.state.in.us).
For more information on Michigan's warranty program, contact Steve Bower
at Michigan DOT, 517-322-5198 (email: bowers@michigan.gov).
To learn more about pavement warranties in general, contact John D'Angelo
at FHWA, 202-366-0121 (fax: 202-493-2070; email: john.d'angelo@fhwa.dot.gov).
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Articles in this issue:
Pavement Warranties Yield Innovation, Quality
Pavement Warranties: Learning from the European Experience
Meet the New Mobile Asphalt Lab
Keeping Up with Context Sensitive Design
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