MATC Spring 2012 Webinar Series: Inform. Innovate. Impact.
Built to Last:
A Look at Sustainable Pavement Design, Construction, and Maintenance
According to results of the U.S. Congress National Surface Transportation Policy and Revenue Study, the U.S. spends
approximately $68 billion annually to maintain its highways, roads and bridges. Congress estimates that over the course of
the next 50 years, the cost of maintaining our nation’s aging infrastructure will soar to $185 billion per year. Please join us
from 12-1 p.m. CST Thursday, February, 16th for a webinar entitled “Built to Last.” During this presentation, MidAmerica Transportation Center faculty will discuss their research efforts geared toward making America’s roads more
sustainable, as well as cost-efficient. This webinar will focus on thin whitetopping asphalt, extending pavement life, the
benefits of utilizing Warm-Mix Asphalt, and methods of more accurately assessing highway pavement damage.
The presentation will feature Dr. Mustaque Hossain, Professor at Kansas State University; Dr. Hosin “David” Lee, Professor
at the University of Iowa, and Dr. Yong Bai, Associate Professor at the University of Kansas.
Technical abstracts on the featured research:
Extending Asphalt Pavement Life Using Thin Whitetopping: Dr. Mostaque Hossain
Due to budget constraints, many highway agencies are becoming interested in pavement preservation or rehabilitation,
rather than reconstruction, to ensure that pavement is in serviceable condition. Thin whitetopping (TWT) is the process of
rehabilitating distressed asphalt concrete (AC) pavements by using a concrete overlay. The current study was conducted in
order to develop a design catalog for existing AC pavements to be overlaid with TWT. The finite element (FE) analysis was
performed with SolidWorks, the 3-D FE software program used to develop this design catalog. The design considered
different TWT thicknesses, existing AC layer thickness and modulus, the bonding condition between TWT and the existing
AC layer, shoulder conditions, and temperature differentials. Each model was built as a three-layer pavement system,
composed of concrete (TWT), asphalt layer, and subgrade soil. The traffic load was modeled as a constant pressure with a
rectangular area applied at the surface and with intensity equal to a tire inflation pressure of 100 psi. The expected lives of
TWT overlays were estimated using fatigue equations developed by the Portland Cement Association (PCA).
Results obtained from this study show that interface bonding condition is the most important factor affecting the behavior of
TWT. With the increase of TWT thickness or existing AC thickness or AC modulus and the addition of a paved shoulder,
concrete tensile stress decreases. Curling stress increases with the increase of TWT thickness and is not a function of AC
properties. A design catalog was developed in terms of pavement service life. Unlike the unbonded TWT with an unpaved
shoulder that results in catastrophic loss of rehabilitated pavement life, bonded TWT is expected to last 10 years. Thus,
proper bonding must be ensured in order to have extended pavement life.
Performance Measures of Warm Asphalt Mixtures for Safe and Reliable Freight Transportation
Warm mix asphalt (WMA) is an emerging technology that can allow asphalt to flow at a lower temperature for mixing,
placing, and compaction. The advantages of WMA include reduced fuel consumption, decreased carbon dioxide emission,
longer paving season, longer hauling distance, reduced oxidation of asphalt, early opening to traffic, and a better working
environment in the field. In the United States, WMA has become popular in recent years. However, to provide a safe and
reliable highway for heavier truck traffic with high tire pressure, WMA mixtures must meet requirements for strength,
stiffness, rutting, and moisture resistance.
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MATC Spring 2012 Webinar Series: Inform. Innovate. Impact.
WMA mixtures with six commercially available WMA additives including CECABASE RT®, Sasobit®, Asphalt-min®, Advera
WMA, Evotherm J1, and RedisetTM WMX, along with an additive-free control WMA mixture and a control HMA mixture, were
evaluated for their air voids, indirect tensile strengths, and moisture susceptibilities. To evaluate long-term performance
reliability over a wide range of traffic and climatic conditions, dynamic modulus and repeated load tests were conducted on
these mixtures using simple performance testing equipment. Based on limited test results, Sasobit®, Evotherm J1 and
RedisetTM WMX were effective in producing WMA mixtures in the laboratory that are comparable to HMA mixtures.
Estimating Highway Pavement Damage Costs Attributed to Truck Traffic
Kansas is a leading meat producer in the United States. In Kansas’ southwest region, there are more than three hundred
feed yards, and several of the nation’s biggest meat processing plants. Primarily, heavy trucks (e.g., tractor trailers) have
been used for transporting the processed meat, meat byproducts, grain, and other related products coming out of this
region. As these industries continue to grow, there will be an increasing number of heavy trucks on the highways. These
trucks cause noteworthy damage to Kansas highway pavements, which in turn leads to more frequent maintenance actions
and, ultimately, more traffic delays and congestion. The primary objective of the current research was to estimate the
highway damage costs attributable to truck traffic that is associated with southwest Kansas’ processed meat (beef) and
related industries.
The researchers developed a systematic pavement damage estimation procedure that synthesized several existing
methodologies, including Highway Economic Requirements System (HERS) and American Association of State Highway
and Transportation Officials (AASHTO) methods. The highway section of US 50/400 between Dodge City and Garden City,
Kansas was selected for this research, and its pavement data were collected for analysis.
This research will be beneficial for the selection of cost-effective transportation modes for the meat processing and related
industries in southwest Kansas, while also helping government agents to assess highway maintenance needs and set
maintenance priorities. Meanwhile, results of this analysis will be valuable for the determination of reasonable user costs.
Based on the research findings, recommendations on the selection of transportation modes are provided, and promising
future research tasks are suggested.
Deteriorating Bridges:
A Discussion about Risk and Stress Analysis
The U.S. Department of Transportation reported that in 2008, one in three urban bridges were structurally deficient.
Researchers at the Mid-America Transportation Center are working to improve the service life of existing highway and rail
bridges, as well as the design code of future bridges, for increased reliability. Join us from 12- 1 p.m. CST Wednesday,
March 14th for a webinar entitled “Deteriorating Bridges.” This webinar will discuss the load and resistance parameters
for determining the reliability of bridges, as well as techniques for evaluating potential damage caused by stress on bridges.
This presentation will feature world renowned faculty member Dr. Andrzej Nowak, a Professor at the University of
Nebraska-Lincoln, and Kansas State University Professor Dr. Robert Peterman.
Technical abstracts on the featured research:
Risk Mitigation for Highway and Railway Bridges
Performance of the transportation network strongly depends on the performance of bridges. They constitute a vital part of
the transportation infrastructure system, and are vulnerable to extreme events such as natural disasters (e.g., hurricanes,
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MATC Spring 2012 Webinar Series: Inform. Innovate. Impact.
earthquakes, floods, major storms), in addition to hazards stemming from negligence and improper maintenance, collisions
(vessels and vehicles), intentional acts of vandalism, and terrorist attacks. These structures must be protected; however, the
current approach to risk is decidedly irrational. Therefore, this project’s objective is to develop efficient risk analysis
procedures for assessment of the actual safety reserve in highway and railway bridges.
We focus on the approach at the system level, using system reliability methods. Sensitivity analysis will be performed to
relate the reliability of bridges and reliability of the transportation network. The results will then be used to identify the critical
parameters. The target risk will be determined depending on consequences of failure and relative costs. Rational selection
criteria will be developed for the target risk level for bridges (components and systems) as a part of the transportation
network, based on the consequences of failure and relative costs. This will involve the development of efficient system
reliability procedures that will be applied to perform sensitivity analysis relating various parameters and reliability. The
resulting sensitivity functions will provide a rational basis for identification of the most important parameters that affect
network performance. Rational selection criteria for the target risk will find important applications for decision making
processes in regards to operation, maintenance, repair, rehabilitation, and replacement.
Assessing the Damage Potential in Pretensioned Bridges Caused by Increased Truck Loads Due to Freight
Movements
Due to the aging and deterioration of bridges, the evaluation of the existing conditions of their structural elements becomes
vital to engineers and public officials when deciding upon how to repair or replace these structures. The ability to obtain
necessary information on these conditions is often expensive and time consuming, especially in the case of concrete
bridges where the reinforcement is not available for inspection. Employing the surface-strain relief method could allow for
accurate evaluation of aged or damaged prestressed members.
The surface-strain relief method was developed to measure initial or pre-existing strains in a concrete member. It involves
relieving the strain in the member and measuring the change in strain. Two methods were tested in this study—the first
used a linear electrical-resistance strain gage and a three-inch-diameter diamond concrete core bit to cut around the gage,
and the second used a laser-speckle imaging device and a diamond cutting wheel to create notches perpendicular to the
axis of maximum strain. Both methods measured the change in strain and related it to within 10 percent of the actual fse.
The method of cutting notches and the laser-speckle imaging device provided a simpler method to be implemented in the
field, while the coring method achieved a higher level of accuracy and precision. In light of these research findings,
selection of transportation modes are provided and promising future research tasks are suggested.
Truck Crashes:
An Analysis of Truck-Related Incidents in the U.S.
According to the U.S. Department of Transportation, truck-related fatalities rose by 8.7 % in 2010. In the Midwest, high
speed winds have been documented as a major cause of truck crashes. Join us from 12-1 p.m. CST Thursday, April 26th
for a webinar entitled “Truck Crashes.” Learn about the significant factors related to fatal and non-fatal large truck
crashes in the U.S. This presentation will be hosted by MATC faculty member and University of Kansas Professor Dr.
Thomas Mulinazzi, and Associate Professor at Kansas State University Dr. Sunanda Dissanayake.
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MATC Spring 2012 Webinar Series: Inform. Innovate. Impact.
Technical abstracts on the featured research:
Mitigating Wind-Induced Truck Crashes
Dangerous weather, particularly high wind speeds, is a commonly cited factor in truck crashes. High wind speeds have
been documented as a perennial cause of truck crashes in Kansas and other Great Plains states. The possibility of reducing
such crashes, and the installation of dynamic message signs along Interstate 70, created a unique opportunity for research
in this field. To this end, crash data were obtained from the Kansas Department of Transportation’s Accident Records
System for all heavy vehicle crashes on I-70 involving strong winds.
The data were analyzed to determine correlations between the vehicle and freight characteristics, crash occurrences, and
weather conditions. The goal of this analysis was to construct a model that could predict the likelihood of wind induced truck
crashes. Ideally, this model could furnish officials with a framework for preempting such crashes by imposing highway
usage restrictions, thereby increasing safety for truck drivers as well as the traveling public. After regressing the data into a
model, however, wind speed was not a statistically significant factor in predicting truck crashes. This finding coincides with
previous literature, and can be attributed to drivers altering their behavior with changing wind speeds. Through this
research, we identified a dilemma zone of wind speeds at which drivers may not be changing their behavior. Furthermore,
specific corridors in Kansas were identified as potential areas for the implementation of a warning system. It is
recommended that Dynamic Message Signs be tied to weather data stations, and/or lighted wind socks be installed on
selected overpass bridges.
Characteristics and Contributory Causes Related to Large Truck Crashes
In the past five years, one-ninth of all traffic fatalities in the United States have involved large trucks, despite the fact that
large trucks accounted for only 3% of registered vehicles and 7% of vehicle miles travelled during this period. This contrast
indicates that truck crashes, in general, tend to be more severe than other crashes, even though trucks constitute a smaller
portion of vehicles on the road. To study this issue, fatal crash data from the FARS was used to analyze characteristics and
factors contributing to truck-involved crashes. Driver, vehicle, and crash-related contributory causes were identified, and as
an extension, the likelihood of the occurrence of these contributory causes in truck-involved crashes, with respect to nontruck crashes, was evaluated using the Bayesian Statistical approach. Likelihood ratios indicated that factors such as
stopped or unattended vehicles and improper following have a greater probability of occurrence in truck crashes than in
non-truck crashes. Further, Multinomial Logistic Regression was used to model the type of fatal crash (truck vs. non-truck),
in order to compare the relative significance of various factors in truck and non-truck crashes.
Factors such as cellular phone usage, failure to yield right of way, inattentiveness, and failure to obey traffic rules also have
a greater probability of resulting in fatal truck crashes. Among several other factors, inadequate warning signs and poor
shoulder conditions were also found to have greater predominance in contributing to truck crashes than non-truck crashes.
By addressing these factors through the implementation of appropriate remedial measures, the truck safety experience
could be improved, which would eventually help to improve the overall safety of the transportation system.
Diesel-Induced Fires
A Look at Enhancing Safety with Droplet Science
More than 180,000 highway fires were reported in 2010, causing $1 billion in property damage in that year alone, according
to the National Fire Protection Association. Join us from 12-1 p.m. CST Thursday, May 17th for a webinar entitled
“Diesel-Induced Fires.” Most crash-related fires in transportation occur due to the rapid ignition of a fuel mist that forms
as a result of the accident’s intensity. Since it is known that pools of diesel burn relatively slowly, a possible method of
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MATC Spring 2012 Webinar Series: Inform. Innovate. Impact.
mitigating such crash-induced fires is to prevent misting by mixing long chained polymer based additives into diesel. MidAmerica Transportation Center researcher and University of Iowa Professor Albert Ratner will be explaining the history of
highway fires, as well as the latest research that utilizes science to mitigate this problem.
Technical abstract on the featured research:
Improving Freight Fire Safety: Assessment of the Effectiveness of Mist Controlling Additives in Mitigating CrashInduced Diesel Fires
Adding long chained polymers to diesel has been proposed as a method to prevent crash fires by arresting the break-up of
diesel fuel into a fine mist in transportation-related accidents. The effect of such additives on the flow properties of diesel
was investigated by studying the impact of poly-butadiene and diesel blend drops on a solid surface using high speed
imaging. The addition of the polymer imparted shear-thinning behavior to diesel, and the base viscosities increased rapidly
with polymer concentration. Four concentrations of the polymer were tested at three different impact speeds under
atmospheric pressure. Maximum spread factors and spreading velocities of the drops were found to decrease with
increasing polymer concentration. This suggests that polymer addition decreases the tendency of diesel to break into
smaller droplets. A numerical model of a drop impact process is being developed using FLUENT 12, and will be used to
study the non-Newtonian effects in the flow of diesel blended with polymers. Results of these experiments and numerical
modeling can facilitate the development of polymers with specific properties to affect the flow of diesel in the desired range
of strain rates.
In the Work Zone:
A Look at Safety of Speed Limits and Work Zone Devices under MASH Testing
Speed-related crashes cost Americans over $40 billion per year, according to the National Highway Traffic Safety
Administration. Please join us from 12-1 p.m. CST Thursday, June 7th for a webinar entitled “In the Work Zone.” MidAmerica Transportation Center researchers Dr. Ronald Faller and Dr. Ghulam Bham will feature their research, and
elucidate lessons learned about work zone sign crash standards and driver behavior. Faller is a Research Professor at the
University of Nebraska-Lincoln, and will be presenting with Research Associate Engineer Karla Lechtenberg. Bham is a
professor at Missouri S&T University.
Technical abstracts on the featured research:
Safety Investigation and Guidance for Work-Zone Devices in Freight Transportation Systems Subjected to
Passenger Car and Truck Impacts with New Crash Standards
The guidelines established in NCHRP Report 350 and MASH for the evaluation of the safety performance of work zone
devices were discussed. Work zone sign supports previously tested with NCHRP Report 350 were evaluated and analyzed
to determine whether they would be acceptable under the MASH safety performance criteria. Eight full-scale tests were
conducted on previously FHWA-accepted work zone sign supports. The test results were then compared to predicted
behavior and, when necessary, the predictions were revised. Recommendations were then made that will help
manufacturers to design, and highway engineers to select, work-zone sign support systems that are likely to provide safe
impact performance for a wide range of passenger vehicles.
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MATC Spring 2012 Webinar Series: Inform. Innovate. Impact.
Safer Work Zones for Heavy and Light Weight Vehicles: Speed Limit Up or Speed Limit Down?
Truck-related crashes constitute a major safety concern for government agencies, the construction industry, and the
traveling public. Due to rising highway maintenance and construction needs, the number of work zones is increasing
throughout the United States; simultaneously, freight movement using trucks is also increasing nationwide. Developing
effective safety countermeasures to reduce truck-related crashes is a major challenge facing government agencies and the
construction industry. The main objectives of this research project are to discover truck-related crash characteristics and to
model truck speeds in the upstream of one-lane, two-way rural highway work zones.
Work zones on two-lane highways are particularly hazardous for trucks due to the disruption of regular traffic flow and
restrictive geometry. The developed models can be utilized to discover possible associations between work zone design
variables and truck speeds, with the purpose of reducing truck-related crash risks. As a result, government agencies and
the construction industry can apply the findings of this research endeavor to improve work zone design and mitigate the
crash risks in work zones.
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