Search results
(1 - 15 of 15)
- Title
- Evaluation of soil resources for sustained vegetative cover of cut-slopes along I-70 near Straight Creek
- Abstract
- A report that evaluates the stability of re-vegetation of high elevation, decomposed, granite cut-slopes by using repeated applications of soil amendments.
- Date
- 2013
- dc.title
- Evaluation of soil resources for sustained vegetative cover of cut-slopes along I-70 near Straight Creek
- Title
- Developing criteria for performance-based concrete specifications
- Abstract
- A report that explains testing of standard mix designs to determine minimum-required performance levels for developing performance-based concrete mix design criteria.
- Date
- 2013
- dc.title
- Developing criteria for performance-based concrete specifications
- Title
- Long-term monitoring of mechanical properties of FRP repair materials
- Abstract
- Over the years, Fiber Reinforced Polymer (FRP) composites have gained popularity in transportation infrastructure as a material able to restore and increase the capacity of existing concrete elements. Properties such as a high strength to weight ratio, non-corrosive nature, durability, and high malleability make FRP materials an appealing alternative in the reinforcement of these structural elements. However, there are still concerns regarding the long-term performance of these repairs. Numerous studies have been completed by means of accelerated aging in the lab. However, behavior of these materials under realistic field conditions has yet to be thoroughly researched. As a result, this project was created to assess the durability of an FRP repair in the Castlewood Canyon Bridge in Colorado. In addition, a laboratory study was conducted to determine the long-term behavior of concrete reinforced with FRP when exposed to various environmental conditions. The specific tasks in this project include data collection and testing plans for field assessment, on-site testing and sample collection, laboratory testing and data analysis, and testing program with a focus on the effects of deicers on FRP. A literature review was developed to consider other concerns that the Colorado Department of Transportation (CDOT) engineers may have on the subject.
- Date
- 2013
- dc.title
- Long-term monitoring of mechanical properties of FRP repair materials, Long term monitoring of mechanical properties of Fiber Reinforced Polymer repair materials, Long-term monitoring of mechanical properties of FRP repair materials (Online)
- Title
- Optimum use of CDOT French and Hamburg data (French and Hamburg tests)
- Abstract
- The Colorado Department of Transportation (CDOT) has been collecting data from the Hamburg Rutter and the French Rutter for over 20 years. No specifications have been written in that time for either the Hamburg Rutter or the French Rutter. This is largely due to the need for a companion test to be developed so dry asphalt mixes would not be designed specifically for passing the Hamburg Rutter test. This report looks at the state of practice within other states that own similar equipment. Cracking tests that could be run with the Hamburg Rutter are examined from a review of literature to determine if there is a suitable companion test for the Hamburg Rutter that would work to keep asphalt levels in the mix high enough to prevent cracking and fatigue.
- Date
- 2013
- dc.title
- Optimum use of CDOT French and Hamburg data (French and Hamburg tests)
- Title
- Implementation of the AASHTO mechanistic-empirical pavement design guide for Colorado
- Abstract
- The objective of this project was to integrate the American Association of State Highway and Transportation Officials (AASHTO) Mechanistic-Empirical Pavement Design Guide, Interim Edition: A Manual of Practice and its accompanying software into the daily pavement design, evaluation, rehabilitation, management, and forensic analysis practices and operations of the Colorado Department of Transportation (CDOT).
- Date
- 2013
- dc.title
- Implementation of the AASHTO mechanistic-empirical pavement design guide for Colorado
- Title
- Evaluation of seismic testing for quality assurance of lime-stabilized soil
- Abstract
- This study sought to determine the technical feasibility of using seismic techniques to measure the laboratory and field seismic modulus of lime-stabilized soils (LSS), and to compare/correlate test results from bench-top (free-free resonance) seismic testing on LSS cylinders to in-situ (surface seismic) testing performed on field-constructed LSS. In addition, this research sought to develop a pilot specification for quality assurance (QA) of LSS using seismic test methods.
- Date
- 2013
- dc.title
- Evaluation of seismic testing for quality assurance of lime-stabilized soil
- Title
- Safety performance functions for freeway merge zones
- Abstract
- This report documents the results of a research project to support CDOT in the area of Safety Performance Function (SPF) development. The project involved collecting data and developing SPFs for ramp-freeway merge zones categorized as isolated, non-isolated and weave. For each of these three categories, data for the period 2007 to 2011 were collected at sites selected to ensure statewide geographical representation and coverage of the range of traffic volume and other variables in each category. Separate SPFs were developed for Total, fatal+injury (FI) and Property Damage Only (PDO) crashes.
- Date
- 2013
- dc.title
- Safety performance functions for freeway merge zones
- Title
- Sustainable stabilization of sulfate-bearing soils with expansive soil-rubber technology
- Abstract
- Pavement construction and maintenance problems due to the presence of sulfates in limestabilized subgrade soils have been widely reported in many transportation projects. In Colorado, problems associated with sulfate-induced distresses have been observed at the Denver International Airport and, more recently, at the U. S. Highway 287 Berthoud By-pass project. It would be desirable if CDOT engineers could count on alternative soil stabilization techniques that are not affected by the potential presence of sulfates.
- Date
- 2013
- dc.title
- Sustainable stabilization of sulfate-bearing soils with expansive soil-rubber technology
- Title
- Colorado mileage-based user fee study
- Abstract
- Colorado could pursue fees based on actual travel as an alternative to the fuel tax. Revenues from mileage-based user fees (MBUF) would not vary based on fleet fuel consumption and would instead return revenue in proportion to use of the roadway network. Too many operational and technological questions remain unanswered, and must be tested and evaluated before the state would be ready to commit to a statewide implementation of this strategy.
- Date
- 2013
- dc.title
- Colorado mileage-based user fee study
- Title
- Development of estimation methodology for bicycle and pedestrian volumes based on existing counts
- Abstract
- This research project enables CDOT to answer the question of whether or not pedestrians and bicyclists are being adequately accommodated by establishing Colorado-specific methodologies for estimating bicycle and pedestrian volumes via a limited sample of existing counts.
- Date
- 2013
- dc.title
- Development of estimation methodology for bicycle and pedestrian volumes based on existing counts
- Title
- Construction cost forecast model : model documentation and technical notes
- Abstract
- This report contains the documentation and supporting technical notes for a statistical model that estimates changes in the price components of the Colorado Construction Cost Index. The model contains two specifications. In the first, the composite construction index is a function of the producer prices of inputs: oil, concrete, steel, labor and equipment. In the second, the composite construction index is a function of the price of oil, wages and nationwide demand for construction services. Implementation The model has been transferred to Colorado Department of Transportation (CDOT)'s economist, who will maintain and operate it to forecast price inflation in construction costs over a thirty-year period, in support of statewide planning and programming.
- Date
- 2013
- dc.title
- Construction cost forecast model : model documentation and technical notes
- Title
- Investigation into effective traffic noise abatement design solutions for mountain corridors
- Abstract
- Traffic noise abatement in mountain corridors can be difficult because traditional roadside barriers may be ineffective due to topography or may not fit the setting. This study examined current best practices from around the world to gather concepts for mitigating traffic noise in mountain corridors in Colorado. A literature review of prospective noise abatement actions found that noise barriers are the most effective direct noise abatement measure, although quieter pavements could have an important supporting role.
- Date
- 2013
- dc.title
- Investigation into effective traffic noise abatement design solutions for mountain corridors
- Title
- Recycled tires as coarse aggregate in concrete pavement mixtures
- Abstract
- The reuse potential of tire chips as coarse aggregates in pavement concrete was examined in this research by investigating the effects of low- and high-volume tire chips on fresh and hardened concrete properties. One concrete control mixture was designed, which well exceeds CDOT Class P concrete requirements.
- Date
- 2013
- dc.title
- Recycled tires as coarse aggregate in concrete pavement mixtures
- Title
- Performance of chip seals using local and minimally processed low traffic volume roadways
- Abstract
- Chip seals are used extensively by CDOT for extending pavement life. Chip seals utilizing locally available and minimally processed aggregates should be a more economical pavement preservation treatment than chip seals constructed with higher quality, more expensive aggregates. Low traffic roadways may not demand such materials to perform acceptably. After four winters and three summers service both experimental chip seals are performing well. It appears that locally available, minimally processed aggregates can be successfully applied as chip seal aggregate on low volume roadways.
- Date
- 2013
- dc.title
- Performance of chip seals using local and minimally processed low traffic volume roadways