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Variability in Bituminous Concrete Pavement Construction
Knowledge
of the variability in acceptable bituminous concrete pavement materials
and construction in Oklahoma is a prerequisite for the development of
successful quality assurance specifications. The objectives of this
study are: 1) to determine the relative magnitudes of variation in the
measured quality characteristics of asphalt pavements due to materials,
sampling, and testing, 2) validate the Oklahoma DOT QA specifications,
particularly the allowable tolerances and pay factors used for product
acceptance, and 3) evaluate the nuclear gauges for asphalt cement and
roadway density determinations.
Sponsors:
Oklahoma Department of Transportation and the Federal Highway Administration
Quality Assurance of HMA Highway Construction
As
part of the the Oklahoma DOT quality initiative, the department has accelerated
the use of statistically-based quality assurance specifications in their
highway construction projects. Nevertheless, the current QA specifications
are not based on sound statistical methods and do not conform to the latest
AASHTO and FHWA requirements.
Sponsors:
Oklahoma Department of Transportation and the Federal Highway Administration
Instrumentation and Evaluation of Bridge Approach Embankments - U.S. 177 Bridges Over Salt Fork River
A problem shared by all state transportation departments involves the "bump at the end of the bridge." Specifically, the problem involves localized settlement of approach embankments whether caused by settlement of the approach embankment itself, settlement of the foundation soils, or a combination of both. The research project involves evaluation of different approach embankment construction procedures. Five of the six approach embankments for the three new bridges on US 177 have been constructed using different procedures. The procedures used include: geotextile reinforced wall, controlled low strength backfill, dynamically compacted granular backfill, flooded and vibrated granular backfill, and a control section using conventional compaction of unclassified borrow. Evaluation of the performance of the different approach embankments will be based on measured stress and deformation values taken from instrumentation installed under and in the backfill materials. Instrumentation used includes total pressure cells in the back of the abutment wall, settlement gages beneath the backfill, inclinometers through the backfill, and piezometers. Surface movement points were installed following paving to further monitor overall settlement. To date, all approach embankments have been constructed and all instrumentation, except surface movement points, have been installed and are being monitored.
Sponsors:
Oklahoma Department of Transportation and the Federal Highway Administration
Hydraulic and Scour Modeling of Bridges on Black Bear and Spunky Creeks
Approximately eighty-six percent of the 577,000 bridges listed in the National Bridge Inventory are constructed over waterways. Statistically, hundreds of these bridges are expected to experience floods in the magnitude of a 100-year flood or greater. Because it is not economically feasible to construct all bridges to resist all conceivable floods or to install scour countermeasures to ensure absolute invulnerability from scour damage at all existing bridges, some risks of failure from future floods may have to be accepted. Every bridge over a stream, whether existing or under design, should be assessed as to its vulnerability to flood in order to determine the prudent measures to be taken. The added cost of making a bridge less vulnerable to scour is small when compared to the total cost of a failure which can easily be two to ten times the cost of the bridge itself. Moreover, the need to ensure public safety and minimize the adverse effects resulting from bridge closure requires our best efforts to improve the practice for designing and maintaining bridge foundations that resist the effects of scour. Because all turnpikes in Oklahoma are part of the national interstate system, the Federal Highway Administration regulations apply to these turnpikes. The OTA has about 1,200 structures on the turnpike system. The purpose of this research is to assist the OTA in evaluating the vulnerability of some of the structures on stream crossings so that a maintenance program can be developed to reduce the risk of failure of structures on turnpikes in Oklahoma. This research investigation determines the scour depths at different bridge piers and evaluates if a bridge is safe for 100- and 500-year floods.
Sponsors:
Benham Group/Oklahoma Turnpike Authority
Carbon Fiber Reinforced Concrete Mix Design Development
Numerous fibers have been considered to reinforce portland cement mortar and concrete. Although carbon fiber has excellent strength and durability, the high cost of the fiber has restricted research in the area of structural concrete. This project will investigate the techniques required to incorporate fibers into concrete and the resulting influence on material properties. Attention will be given to applications where a high performance concrete containing carbon fibers will permit a reduction or elimination of conventional steel reinforcement.
Sponsor:
Dupont
Transverse Cracking of Asphalt Pavements
The
purpose of this research is to assess the influence of the design, construction,
materials, maintenance, and climate factors on the occurrence and distribution
of depressed transverse cracks in asphalt pavements. The research
program involves literature review, and the collection and analysis of
field data to evaluate the effects of the above factors.
Sponsors:
Oklahoma Department of Transportation and the Federal Highway Administration
Determination of the Engineering Properties of Flowable Fill
Flowable
fill is a high-slump mixture of cement, flyash, sand and water.
This material may be used in lieu of traditional granular backfill for
utility trenches, pavement repairs, etc. The
Sponsors:
Oklahoma Ready Mixed Concrete Council
Determination of the Engineering Properties of "Blended" Asphalts
Asphalt cement is composed of various fractions which may be separated be mechanical or chemical processes. Certain components have been shown to be detrimental to the performance of in-service asphalt cement. The relative effect of each of four fractions of the engineering properties of AC-20 will be determined in this study.
Sponsors:
Oklahoma Department of Transportation
Effect of Xerox Toner on the Properties of Asphalt Cement
This study investigates the use of waste Xerox toner as an extender/filler of asphalt cement. The modified asphalt cement is then evaluated in terms of its performance in asphalt concrete.
Sponsors:
Xerox Corporation
Determination of the AASHTO Layer Coefficients for Bituminous Mixes
The AASHTO pavement design procedure requires the estimation of various "layer coefficients." These coefficients translate into the relative strength contribution of each pavement support layer. This project is based on determining the layer coefficients for all types of bituminous mixes currently used by ODOT.
Sponsors:
Oklahoma Department of Transportation
Review and Assessment of Continuous Reinforced Concrete Pavement in Oklahoma
The construction of CRCP uses continuous longitudinal steel to minimize
transverse joints. The joints only occur at the end of a construction
period or at intervening structures such as bridges. Minimizing the number
of joints provides a smoother riding surface. Cracking of the pavement
must occur to relieve stresses resulting from shrinkage of the concrete
and temperature changes. Proper design of CRCP will result in cracking
that occurs with regular spacing and small individual crack widths. It
is imperative that the crack width remain small to prevent corrosion of
the reinforcement. The amount of longitudinal steel, concrete properties,
subgrade, subbase, construction season, curing temperature, joint design,
and environmental factors such as temperature and humidity all affect
the performance of CRCP. These factors must be taken into account during
the design, specification, and construction phases to insure the CRCP
performs adequately. The Oklahoma Department of Transportation (ODOT)
has employed CRCP for many highway projects around the state and expects
to use CRCP in the future. To insure the success of future CRCP projects,
ODOT must review its current design process, compare current practices
with those nationwide, and assess the performance of past CRCP projects
to identify problems that occurred. In addition, to insure the future
performance of existing CRCPs, effective methods of repair must be identified.
This research will respond to these issues and help to provide ODOT with
the tools needed to successfully address future needs.
Sponsor:
Oklahoma Department of Transportation
The Development of D45 Wire in Concrete
The objective of this research is to determine the development of D45 deformed wire compared with that of deformed #6 bars. To answer this question, a series of 16 splice tests be conducted on D45 wire and #6 bars to compare the development performance. The splice tests will use a setup similar to that used on the effect of epoxy coating on the development of welded wire fabric. This test setup combines ease of construction of both the test frame and test specimen with accurate modeling of performance of actual reinforced concrete members.
Sponsor:
Ivy Steel & Wire
Fatigue Assessment of Bridge Members Based on In-Service Stresses
Structural designs are necessarily based on conservative assumptions regarding
support conditions, loads, and load distributions. Typically, these same
assumptions are used to calculate stresses in existing structures, resulting
in calculated stresses higher than the true stresses in the structure.
The first objective of this project is to develop a data acquisition system
that the Oklahoma Department of Transportation (ODOT) can use to measure
the stresses in a functioning highway bridge. The second objective is
to develop an analytical procedure allowing ODOT to use the acquired data
to more accurately assess the structural status of the bridge. This more
accurate assessment will both improve safety and help direct maintenance
funds to locations where they are most needed.
Sponsors:
Oklahoma Department of Transportation and Federal Highway Administration.
Durability of Concrete Made with Marginal Aggregate
The influence of mix parameters on the freeze-thaw resistance of concrete will be investigated. The goal is to improve the durability of concrete made with aggregate which can produce D-cracking.
Sponsor: Oklahoma Department of Transportation.
Concrete Pavement Construction Joints
Simulated traffic loads will be imposed on pavement joints to determine the relationship between mix parameters and durability of construction joints.
Sponsor: Oklahoma Department of Transportation.
Improving Accuracy of Early Estimates
For any capital investment venture an early estimate is prepared to enable the business unit to make reliable decisions regarding the economic feasibility to justify pursuing the project. An early estimate is prepared based on limited scope definition and little information regarding the specific parameters that will be needed in the completed facility. The purpose of this research is to provide a methodology to improve the accuracy of early project estimates to allow the business unit to make better decisions. The scope of the research involves identification of estimating indices for projects in the oil and gas industry and to correlate the indices with the accuracy of estimates. A computer model will be developed to identify the accuracy range of an early estimate based on the estimating index. This research will also develop a best practices guide to improve the accuracy of early estimates.
Sponsor: Construction Industry Institute.
Macro Trend Analysis of Project Changes
Data from numerous competed projects will be collected and analyzed to identify and quantify factors that are common among projects that are indicators of change. A trend analysis will be performed to evaluate the full impact of project changes including the ripple effect.
Sponsor: Construction Industry Institute.
ODOT Rural Bridge Deck Replacement Program
This project evaluates the inventory of rural county bridges and develops a bridge deck replacement system utilizing a series of precast concrete panels. Criteria for the system include HS20 heavy highway loading, utilization of readily available equipment, and county work forces.
Sponsor: Oklahoma Department of Transportation.