| Abstract XIII |
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| Concrete Cylinder 1987 |
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Concrete Cylinder Mold Investigation
In 1985, Oregon State Highway Division (OSHD) began using single use plastic cylinder molds in the field and in pre-stress yards for acceptance testing. Before this time, field inspectors had been using steel, paper, and tin molds, while the pre-stress yards had been using re-usable steel cylinder molds. A major reason for changing to plastic molds was that the tin and steel molds were producing cylinders that were out of round and not in compliance with specifications.
By the end of the 1985 construction season, one of the pre-stress yards challenged the compressive strength test results of the cylinders cast in plastic molds. The pre-stress yard felt that the plastic molds produced lower compressive strengths than the steel molds. In December 1985, the OSHD Materials Section began a research study to determine the cause for the observed differences in strengths of cylinders cast by the pre-stress yard vs. cylinders cast by OSHD inspectors. Several factors affecting strength were considered, including types of molds, method of curing, method of transporting, flexibility of molds, and thermal conductivity of molds. The major emphasis of the research was to be on the difference in the compressive strengths between cylinders cast in the plastic molds and steel molds.
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| Concrete Cylinder Mold 1986 |
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Concrete Cylinder Mold Investigation 1986
Oregon State Highway Department began using plastic single-use concrete cylinder molds as early as 1983 for trial mixes at OSHD using plastic molds for acceptance testing in the summer of 1984, and two additional plants switched to plastic molds in August of 1985.
In December of 1985, OSHD Material Laboratory began an investigation into the compressive strength difference between cylinders cast in steel molds versus plastic molds.
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| Table-1 and Table-2 Asphalt |
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Comparison of Oregon State Highway Division Table-1 and Table-1 Asphalt
The objective of this study was to compare the effect of using the Oregon State Highway Division (OSHD) modified Table-1 asphalts and the OSHD modified Table-2 asphalts in asphalt concrete; the primary factors for comparison were reflected and thermal cracking. Crack information obtained prior to paving was compared to crack information obtained two years after paving.
In 1989, an overlay project was constructed in Southern Oregon. The project consisted of one control section and one test section. Witco AC-15 asphalt cement, representing Table-1, was used in the control section. Chevron AC-20 and Idaho AC-20 asphalt cements, representing Table-2, were used in the test section. After two years of service. The control section showed significantly more reflective cracking than the test section. This indicates the Table-2 asphalt was more effective than Table-1 asphalt in reducing reflective cracking. However, the effect of cold temperatures on the development of cracking in both the control and test sections was not clear. It may be expected that Table-2 asphalts would have better thermal resistance than Table-1 asphalt because Table-2 asphalts are less temperature susceptible than Table-1 asphalts. The study conclusions were based on limited information. Further verification, if necessary, should be conducted in a wider scale.
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| Cold Recycle Pavement |
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Cold Recycle Pavement Using Urea Urethane Dispersion Agent and Rubber
This research study was a joint venture of the Oregon Department of Transportation (ODOT), Evans, Loosley, Inc., and Roseburg Paving Company, to evaluate the use of Urea Urethane Dispersion (UUD) agent, with finely ground tire rubber, high float emulsion, and recycled asphalt pavement (RAP). A conventional mix design procedure was not acceptable for the control and test mixes due to the variables associated with the fine, dense RAP gradation, and the compatibility of the high float emulsion with the UUD and rubber. The mixture blend that was used for a control section included: RAP with 2% HFE-150 plus 0.5% added mixing water. The test section included RAP with 1.5% HFE-150 plus 0.5 UUD, 1.8% fine ground tire rubber plus 1% added water.
Approximately 280 tons of control mix and 280 tons of test mix were placed as an overlay. Several hours after being layed, the mixtures could not be compacted without hairline cracking. The mixtures were blanket rolled, dusted with #10-0 material and opened to traffic. After two days under traffic, it was determined that the control section was only partially successful and the test section had not set up. Shortly thereafter, the entire pavement overlay was removed.
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| Fuels and Asphalts |
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Characterization of Fuels and Asphalts
This report describes a study of thirteen samples of fuel oil, original asphalt, and recovered asphalt received in 1983 May. Some additional work on a set of three samples received in 1982 October was also done.
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| Brugg Cable Mesh Final |
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Brugg Cable Mesh Rockfall Fence Final Report
In 1991 a Brugg Cable Mesh Rockfall Fence was installed along Interstate 84 (I-84) 52 miles (84km) east of Portland to prevent large boulders, that roll down the 1500-foot (460 m) long talus slope of Shellrock Mountain, from entering the travel lanes. This was one of the first major installations of this fence on an Interstate Highway and was an FHWA experimental features project.
The Brugg Cable Mesh Rockfall Fence was selected for this site because it was the most cost effective and visually acceptable option that could be built on top of the existing bin wall. Also, because it could efficiently stop the large boulders that entered the travel lanes approximately every three years with the incorporation of a friction brake energy dissipater. During design, the standard tie-back anchors were eliminated to prevent damaging the talus slope and the Historic Columbia River Highway.
This was the first instillation of the fence both for ODOT and the contractor. Both considered construction very simple except for difficulties spray painting the fence on site due to the high winds. It was found that during design it is critical to have an accurate ground profile along the fence line to prevent changes during construction.
On August 8, 1992 a 1.7-ton (1.5-metric ton) boulder impacted a 6.5-foot (2.0 m) high mesh section three feet (0.9m) from a post. The fence stopped the boulder, however, the post and foundation rotated 20 degrees due to the foundations inability to resist the impact moment without the tie-backs. The velocity of the rock at impact was estimated to be 33 feet/second (10 m/sec) and the kinetic energy was approximately 66,000 foot-ponds (89,000 joules). The damage to the fence from this event was minor and has been repaired.
In the winter of 1993-1994, a 750-pound (340 kg) boulder impacted the second from the last mesh section, one foot (0.3 m) from the top. It resulted in only superficial damage not requiring repair.
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| Brugg Cable Mesh Constr |
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Brugg Cable Mesh Rockfall Fence Construction Report
The Brugg Cable Mesh Rockfall Fence was installed in 1991 along I-84 from MP 52.1 to 52.7 to prevent large (.3 foot diameter) rocks from entering the travel lanes. This was one of the first major instillations of the Brugg Cable Mesh Rockfall Fence in the United States and it was a FHWA experimental features project. The fence is a patented proprietary item and consists of cable mesh attached to H-beam posts that incorporate a friction brake. The fence was installed in the Columbia Rive Gorge Scenic Area; to minimize its visual impact, it was painted a dark earth tone.
The bid price of installing the fence was $27.00 per square foot face. Even though this was the contractor’s first instillation, both the contractor and the Oregon Department of Transportation (ODOT) inspector considered the constructability very easy.
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| Effect of Aging |
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Effect of Moisture and Aging on Asphalt Pavement Life Part 2
This report presents the results of a study to evaluate the effect of oxidative aging on asphalt mixtures. The results of tests on field core samples from 8 projects representing different regions in Oregon were compared with those from laboratory mixture samples for selected projects subjected to accelerated aging tests. The study also involved laboratory tests on asphalt used in those projects selected for the laboratory aging process for mixtures.
The procedure selected for aging laboratory mixtures involved using a Pressure Oxygen Bomb (POB), a sealed container in which mixture and/or asphalt samples were subjected to pure oxygen at 100 psi pressure at 140ºF (60ºC), for periods of up to five days. The asphalt samples were ages on a Fraass plaque to achieve minimum disturbance of the sample, and the degree aging assed by change in the Fraass breaking temperature.
The results of this study showed that the POB was an effective means of producing measurable changes in both mixtures and asphalt samples. However, the mixture properties were substantially different to those measured for the field core samples, while the asphalt properties were similar. The study also indicated that aging rate is a function of the air voids in the mixture, and the amount of asphalt and its properties. The study therefore confirms the well established principle that low air voids and thick asphalt films are required to produce durable asphalt mixtures.
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| Effect of Moisture |
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Effect of Moisture on Asphalt Pavement Life
Considerable research has been carried out on the effect of water on asphalt mixtures, and test methods to investigate the effect of water have been developed. However, most of this work has been related to stripping and the effect of additives, where external water enters or affects the pavement following construction. There is little published research directly concerned with the problems of mixing moisture in hot mixed asphalt concrete and long-term durability related to mixing moisture.
This report presents the results of a study to investigate the effects of mixing moisture on mechanical properties of asphalt mixtures. The potential benefits of lime and Pavebond Special were also investigated. The repeated load diametral test device was used to measure the resilient modulus, fatigue, and permanent deformation characteristics of laboratory specimens prepared with and without moisture (0, 1, and 3%) and with and without lime (0, 1%) and Pavebond Special (0, 0.5%). Mixtures were prepared which were representative of two projects for which considerable field data were available. One project utilized marginal aggregate and the other good quality aggregate. To evaluate the long-term durability of mixtures, they were tested before and after conditioning using the Lottman approach.
The test results showed that inferior performance occurred for mixtures with 3% moisture, but was most pronounced in mixtures with high void contents. However, the mixtures with marginal aggregate showed improved performance at 1% moisture content, associated with their lower void contents, which may be due to absorbed moisture preventing asphalt absorption and the higher asphalt content of these mixtures. The addition of lime resulted in distinct improvement of performance for moist samples from the project which had good quality aggregate, but high air void contents. However, neither additive showed substantial benefit for moist mixtures from the project with marginal aggregate and low air void contents.
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| Low-Flow Stream Flow |
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Estimating Flow-Duration and Low-Flow Frequency Statistics for Unregulated Streams in Oregon
Flow statistical datasets, basin-characteristic datasets, and regression equations were developed to provide decision makers with surface-water information needed for activities such as water-quality regulation, water-rights adjudication, biological habitat assessment, infrastructure design, and water-supply planning and management. The flow statistics, which included annual and monthly period of record flow durations (5th, 10th, 25th, 50th, and 95th percent exceedances) and annual and monthly 7-day, 10-year (7Q10) and 7-day, 2-year (7Q2) low flows, were computed at 466 streamflow-gaging stations at sites with unregulated flow conditions throughout Oregon and adjacent areas of neighboring States. Regression equations, created from the flow statistics and basin characteristics of the stations, can be used to estimate flow statistics at ungaged stream sites in Oregon. The study area was divided into 10 regression modeling regions based on ecological, topographic, geologic, hydrologic, and climatic criteria. In total, 910 annual and monthly regression equations were created to predict the 7 flow statistics in the 10 regions. Equations to predict the five flow-duration exceedance percentages and the two low-flow frequency statistics were created with Ordinary Least Squares and Generalized Least Squares regression, respectively. The standard errors of estimate of the equations created to predict the 5th and 95th percent exceedances had medians of 42.4 and 64.4 percent, respectively. The standard errors of prediction of the equations created to predict the 7Q2 and 7Q10 low-flow statistics had medians of 51.7 and 61.2 percent, respectively. Standard errors for regression equations for sites in western Oregon were smaller than those in eastern Oregon partly because of a greater density of available streamflow-gaging stations in western Oregon than eastern Oregon. High-flow regression equations (such as the 5th and 10th percent exceedances) also generally were more accurate than the low-flow regression equations (such as the 95th percent exceedance and 7Q10 low-flow statistic).The regression equations predict unregulated flow conditions in Oregon. Flow estimates need to be adjusted if they are used at ungaged sites that are regulated by reservoirs or affected by water-supply and agricultural withdrawals if actual flow conditions are of interest. The regression equations are installed in the USGS StreamStats Web-based tool (http://water.usgs.gov/osw/streamstats/index.html, accessed July 16, 2008). StreamStats provides users with a set of annual and monthly flow-duration and low-flow frequency estimates for ungaged sites in Oregon in addition to the basin characteristics for the sites. Prediction intervals at the 90-percent confidence level also are automatically computed.
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| Ice Alert |
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Evaluation of Ice Alert
One of the goals of road and highway agencies has been to reliably warn motorists of hazardous conditions, particularly the presence of ice on the road. ODOT set out to evaluate a product called Ice Alert® designed for that purpose.
The product was principally tested to determine its degree of reflectivity and sensitivity to temperature changes. The product was evaluated through laboratory and field tests to develop cost data, document maintenance problems, evaluate sitting criteria and determine driver reactions to the device.
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| Older Driver in Oregon |
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The Older Driver in Oregon: A Survey of Driving Behavior and Cessation
Although there are several instances where older drivers have had their licenses taken away, no state-wide study of either the reasons for driving cessation or the need for transportation after driving cessation have been conducted. Using a sample of Oregon drivers and former drivers this project completed surveys by mail, and phone. Questions focused on the factors influencing driving cessation, physical and emotional barriers delaying driving cessation, modes of alternative transportation, and warning signs that caused a driver to stop driving.
The study found that changes in driving patterns, occurred gradually and late, mostly for respondents in their late 70’s or early 80’s. Those most likely to have chosen to stop driving were older, depressed females in poorer health who were living in senior housing, using alternative transportation when available, making fewer trips, and seeing fewer limitations associated with using alternative transportation. Relocation to improve access to transportation alternatives was not seen by most respondents as a viable option. These and other findings are thoroughly discussed in this report.
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| Rainfall Analysis |
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Regional Precipitation-Frequency Analysis and Spatial Mapping of 24-Hour Precipition for Oregon
For this study regional frequency analyses were conducted for precipitation annual maxima in the state of Oregon for the 24-hour duration. A total of 693 precipitation gages in Oregon, southern Washington, western Idaho, northern California and northern Nevada were included in the study, representing 34,062 station-years of record. A regional analysis methodology was utilized that pooled data from climatologically similar areas to increase the dataset and improve the reliability of precipitation-frequency estimates. The regional analysis methodology included L-moment statistics, and an index-flood type approach for scaling the annual maxima data. L-moment statistics were used to: characterize the variability, skewness and kurtosis of the data; measure heterogeneity in proposed homogeneous sub-regions; and assist in identification of an appropriate regional probability distribution.
Spatial mapping techniques were employed for mapping of the precipitation-frequency information. This included spatial mapping of at-site means, L-moment ratio values of L-Cv and L-Skewness, and mapping of precipitation for selected recurrence intervals. Procedures were employed to minimize differences between mapped values and observed station values in a manner that was consistent with the regional behavior of the data and also recognized uncertainties due to natural sampling variability.
Color-shaded isopluvial maps were developed for the 6-month, 2-year, 10-year, 25-year, 50-year, 100-year, 500-year, and 1000-year precipitation recurrence intervals. Electronic gridded datasets are available for use in creation of GIS applications that utilize precipitation-frequency information.
A catalog of extreme storms was assembled that lists precipitation events that exceeded a 20-year return period for the various climatic regions. The information from the storm catalog was also used to conduct seasonality analyses identified the occurence frequency of extreme storms by month. In particular, the seasonality analyses identified those months that were the most likely and least likely for an extreme event to occur. This information is useful in rainfall-runoff modeling and can be used in conducting hydrologic analyses throughout the Oregon study area.
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| Advisory Curve Speeds |
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Methodologies for Estimating Advisory Curve Speeds on Oregon Highways
This report reviews an Oregon research effort to evaluate the identification and marking of advisory speeds on Oregon highways. In particular, this research effort focused on the implications of modified advisory speed thresholds and identification procedures following the most recent and the upcoming MUTCD and the Traffic Control Devices (TCD) Handbook recommendations. The primary objectives of this research effort were to help identify the basis for the current and proposed advisory speed posting procedures (with specific attention to the horizontal curve location on rural roads and passenger vehicle condition), to evaluate Oregon placement strategies at a variety of locations, and to identify potential criteria for establishing advisory speeds for these curved sections on Oregon highways. Included with this evaluation is an assessment of associated costs for implementation of a modified advisory speed policy in Oregon. Through the use of both manual and digital ball-bank devices, the report identifies compliance of current and future advisory speed thresholds for both State- and county-maintained roads, expected costs for upgrading State-maintained facilities, evaluation of alternative computational methods, and an assessment of the differences observed between the two different ball-bank devices.
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| Weigh-in-Motion Data |
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Development of Truck Axle Spectra From OR Weigh-in-Motion Data for Use in Pavement Design and Analys
Four weigh-in-motion (WIM) sites in Oregon, representing high, moderate, and low average daily truck traffic (ADTT) volumes, were selected to characterize axle weight and spacing spectra on Oregon state highways. Seasonal variations were considered by investigating data occurring over the four seasons: winter, spring, summer, and fall. WIM data were cleaned and filtered, and analyzed. Axle data, including group and individual axle weights as well as axle spacings, were evaluated. Hourly truck volumes were also examined. Results were summarized and statistics were developed for the characteristic data. The characterized Oregon WIM axle data were incorporated into the Mechanistic Empirical Pavement Design Guide (MEPDG) software program to permit State and ADTT volume-specific axle weight spectra, average axle group spacing, and hourly volume data to be used in the pavement analysis/design. In order to implement the Oregon WIM data, a "virtual" truck classification was created in the MEPDG program. The Oregon-specific date that were required for input into the MEPDG were hourly truck volume distribution, site-specific axle weight data, average number of axles per truck, and average axle spacing. Implementation of the Oregon WIM data will improve the pavement design process in the State by designing to more realistic local loading conditions.
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| Solar-Powered Markers |
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Evaluation of Solar-Powered Raised Pavement Markers
An evaluation of a limited number of solar-powered raised pavement markers (SRPMs) was conducted to determine if this type of marker would be more visible than retroreflective markers in some situations on Oregon highways. SRPMs typically use Light Emitting Diodes (LEDs) that are powered by solar cells. Some markers have retroreflective surfaces as well. The Oregon Department of Transportation, Research Unit, performed preliminary tests which included environmental tests (extreme temperatures, immersion), optical performance tests, and observation tests. Selected markers were sent to the Federal Highway Administration's Photometric and Visibility Laboratory (PVL) at the Turner-Fairbank Highway Research Center in McLean, Virginia for additional evaluation. A series of tests was performed to measure both the LED signal and the retroreflected light. It was found that each type of marker had significant shortcomings, so the project was terminated prior to field trials being performed.
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| ODOT Project Delivery |
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Evaluation of Oregon Department of Transportation Project Delivery
This report summarized analysis of Oregon Department of Transportation (ODOT) methods of insourced and outsourced project delivery using the data obtained from ODOT reporting systems, ratings of project effectiveness by ODOT Area Managers and by construction contractors, and interviews with ODOT Area Managers and managers from engineering consulting firms that ODOT uses for outsourced design-bid-build projects. Results of a literature review and DOT survey were published in an interim report in December 2003. Guidelines, including a decision tree, are provided for assignment of projects for insourced design-bid-build, outsourced design-bid-build, or design-build delivery.
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| 2007 Needs and Issues |
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2007 Transportation Needs and Issues Survey
The Transportation Needs and Issues Survey was condected in October and November of 2006 by the Survey Research Center at Oregon State University. The survey used a random digit dialing telephone survey method and completed a total of 1,013 interviews. The random sample was stratified by ODOT Region and contained at least 200 completed interviews per region. The statewide data was weighted to reflect the different population sizes within each region, household non-response by region, the variable number of landlines within a household, the number of adults in the household, and population characteristics of gender, age, and race/ethnicity.
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