Search results
(1 - 20 of 151)
Pages
- Title
- Internal curing of high performance concrete using lightweight aggregates and other techniques
- Abstract
- Internally cured concrete has been rapidly emerging over the last decade as an effective way to improve the performance of concrete. Internal curing (IC) holds promise for producing concrete with an increased resistance to early-age cracking and enhanced durability. It is a simple and effective way to cure concrete.
- Date
- 2014
- dc.title
- Internal curing of high performance concrete using lightweight aggregates and other techniques
- 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
- Full closure strategic analysis
- Abstract
- The full closure strategic analysis was conducted to create a decision process whereby full roadway closures for construction and maintenance activities can be evaluated and approved or denied by CDOT Traffic personnel. The study reviewed current full closure practices in Colorado and throughout the country, gathered stakeholder input, and employed an iterative development process to reach a systematic decision tool that can be applied to judging the merits of full closure scenarios. A number of case studies were created to more fully understand the methodology and adjust the tool to best match real-world scenarios. Project deliverables include a technical report and a series of electronic forms that can be used by CDOT to work through the process.
- Date
- 2014
- dc.title
- Full closure strategic analysis, CDOT full closure strategic analysis
- Title
- Evaluation of the FHWA traffic noise model, TNM, for highway traffic noise prediction in the state of Colorado
- Abstract
- In 2002, CDOT undertook this study in an effort to better understand the complexities of the Federal Highway Administration's new Traffic Noise Model (TNM). The research involved three analysis.
- Date
- 2006
- dc.title
- Evaluation of the FHWA traffic noise model, TNM, for highway traffic noise prediction in the state of Colorado
- Title
- Design of mechanically stabilized earth wall connections and end of walls subjected to seismic loads
- Abstract
- A report that examines the impact that new AASHTO design requirements may have on connection details in mechanically stabilized earth walls.
- Date
- 2014
- dc.title
- Design of mechanically stabilized earth wall connections and end of walls subjected to seismic loads
- Title
- CDOT rapid debris removal research project
- Abstract
- Highway debris represents a traffic safety problem that requires a prompt response from state or local transportation agencies. The most common practice for debris removal currently is for agency personnel to leave their vehicles and remove the debris by hand in the case of large debris (tires, lumber, freight loss, rock fall) or to sweep traveled lanes shoulders, or intersections in the case of crashes, mechanical failure, or embankment erosion. This exposes agency workers to safety risks, especially on high-speed and/or high-volume roadways. Currently, the Colorado Department of Transportation (CDOT) has no widely distributed formal guidelines for safely and effectively removing debris from the roadway.
- Date
- 2014
- dc.title
- CDOT rapid debris removal research project
- Title
- Improving the performance of roadside vegetation
- Abstract
- The purpose of this study was to determine the impact of a magnesium chloride-based deicer, a sodium chloride-based deicer, and the major salts contained in these deicers on seed germination and seedling growth and development of fifteen species of grasses and forbs native to Colorado. Seven of the fifteen species performed well at the low and medium concentrations of the salts and solutions; these are plants that can likely germinate in roadside areas.
- Date
- 2011
- dc.title
- , , ,
- 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
- A comparison of freeway and parallel major arterial corridors : a study of safety patterns in the Denver Metropolitan area
- Abstract
- This research project observes and analyzes traffic and accident history on Colorado State Highways and parallel arterial roads within a major southeast section of the Denver Metropolitan Area. The project focuses on the freeway section of C-470 between S. Santa Fe Drive and I-25 and comparisons with I-25 and the corresponding parallel east-west regional arterial corridors.
- Date
- 2015
- dc.title
- A comparison of freeway and parallel major arterial corridors : a study of safety patterns in the Denver Metropolitan area
- Title
- Monitoring wildlife-vehicle collisions : analysis and cost-benefit of escape ramps for deer and elk on U.S. Highway 550
- Abstract
- Wildlife fencing along highways can lower wildlife-vehicle collision rates by excluding animals from the road right-of-way. Still, animals can breach fencing and end up trapped within the fencing along the highway right-of-way, exposing wildlife and motorists to the risk of collision. Wildlife escape ramps are designed to allow animals safe passage out of the right-of-way. Few recommendations exist on effective design of escape ramps and monitoring data are limited.
- Date
- 2015
- dc.title
- Monitoring wildlife-vehicle collisions : analysis and cost-benefit of escape ramps for deer and elk on U.S. Highway 550
- 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
- Performance of thin bonded epoxy overlays on asphalt and concrete bridge deck surfaces
- Abstract
- This study is the evaluation of two thin bonded epoxy overlays. These two products were compared on the basis of physical properties, including mean texture depth, surface friction, bond strength, ability to stop chloride intrusion, and anti-icing properties, as well as traffic safety and cost. Both overlays worked as intended when they were initially applied on the bridge decks. Mean texture depth and friction testing have shown that they both provide a durable wearing surface with good traction.
- Date
- 2014
- dc.title
- Performance of thin bonded epoxy overlays on asphalt and concrete bridge deck surfaces
- Title
- Evaluation of guardrail embedded lighting system in Trinidad, Colorado
- Abstract
- This report provides information on the design considerations of the embedded highway lighting design on Interstate-25 in Trinidad, Colorado, in terms of visibility. The information is based on visibility characterizations of small targets using luminance, illuminance, and contrast calculations as well as participant input on the detectability of small targets.
- Date
- 2014
- dc.title
- Evaluation of guardrail embedded lighting system in Trinidad, Colorado
- Title
- Use of waste tires, crumb rubber, on Colorado highways
- Abstract
- The goal of this research project is to evaluate the performance of the crumb rubber test sections compared with the conventional control section and depending on performance, develop Colorado-specific materials and construction specifications for ground tire modified asphalt pavements. Also, the research project aims to develop guidelines and best management practices for the construction of ground tire modified asphalt pavements. Transverse cracking began in the rubber modified sections after 22 months of service and longitudinal cracking began after 29 months. The control sections have no transverse cracking to date with longitudinal cracking beginning to appear after 56 months.
- Date
- 2014
- dc.title
- Use of waste tires, crumb rubber, on Colorado highways
- 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
- Assessment and placement of living snow fences to reduce highway maintenance costs and improve safety (living snow fences) study no: 047-10
- Abstract
- Living snow fences (LSF) are designed plantings of trees and/or shrubs and native grasses along highways, roads and ditches that create a vegetative buffer that traps and controls blowing and drifting snow. These strategically placed fences have been shown to be cost effective in reducing highway maintenance associated with blowing and drifting snow conditions.
- Date
- 2015
- dc.title
- Assessment and placement of living snow fences to reduce highway maintenance costs and improve safety (living snow fences) study no: 047-10
- Title
- Benefit-cost analysis of CDOT fixed automated spray technology (FAST) systems
- Abstract
- The study found that FAST systems have demonstrated the potential to reduce the number of crashes and reduce the cost of winter maintenance activities, if sited at appropriate locations (e.g., high-traffic-volume ice-prone ramps). However, improved installation techniques and involvement of maintenance crews during FAST installation are necessary to further increase the cost-effectiveness of a FAST system deployment. Extra effort will be made in sharing the information gained from this research study by focusing on CDOT personnel involved in planning, design, construction, operation and maintenance of FAST systems.
- Date
- 2014
- dc.title
- Benefit-cost analysis of CDOT fixed automated spray technology (FAST) systems
- 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