1997 HBP QC for Pay Pilot Projects with Void Acceptance PDF Download

Author: Bud A. Brakey
Publisher:
ISBN:
Category : Pavements, Bituminous
Languages : en
Pages : 90

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Book Description

Author: Bud A. Brakey
Publisher:
ISBN:
Category : Pavements, Bituminous
Languages : en
Pages : 98

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Book Description
Summaries and analyses of three Void Acceptance (VA) projects are reported and compared with previous VA and quality assurance and quality control (QA & QC) projects. For two of the three projects, the voids filled with asphalt (VFA) averaged 77% (design criteria was 65-75%) and percent air voids (AV) averaged 3.2% (design target was 4.0%). Because compacted bulk specific gravity field tests were higher than lab-mixed design values, for all processes, field AV and voids in mineral aggregate (VMA) averaged 0.4% below design values. VMA was easily met after field targets were adjusted.

Author: Bud A. Brakey
Publisher:
ISBN:
Category : Pavements, Bituminous
Languages : en
Pages : 92

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Book Description
In 1993, the Colorado Department of Transportation (CDOT) recognized that specifying HBP volumetric properties would likely provide superior pavements. A long range goal was set for acceptance to be based on voids properties. Beginning in 1993, a series of void acceptance (VA) pilot projects were let to contract; by the end of 1996, nine had been completed. Six had conventional mix designs. The last three were designed using Superpave technology. The data for the nine VA projects are summarized and compared with data from concurrent CDOT projects under Quality Level Analysis (QLA).

Author: Pui-shum B. Shing
Publisher:
ISBN:
Category : Concrete
Languages : en
Pages : 182

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Book Description
This report summarizes the findings of a study whose primary objectives are to determine the cause of extensive transverse cracking that has been observed in some existing bridge decks, and to identify the change of material specifications and construction practice that is necessary to reduce the severity of deck cracking. To achieve these goals, recent studies on the cause of bridge deck cracking were reviewed, an experimental study was conducted to compare the shrinkage properties of different concrete mixes, and the current material and design specifications and construction practice adopted by the Colorado Department of Transportation (CDOT) were reviewed to identify areas that need improvement. A survey was conducted on seven newly constructed bridges to examine the extent of cracking in concrete decks that were constructed with the different mix designs and curing procedure that were currently used by CDOT.

Author: Sarosh I. Khan
Publisher:
ISBN:
Category : Travel time (Traffic engineering)
Languages : en
Pages : 148

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Book Description
This report represents the findings of a study that demonstrates the feasibility of estimating link travel time and speed in real-time for rural, mountainous sections of interstate freeway in Colorado using vehicles instrumented with global positioning system (GPS) receivers, serving as probes in traffic streams. The system configuration developed includes a cost-effective, portable GPS deployment unit, communication links to a server PC and an integrated prototype system for vehicle tracking and estimating link travel time statistics. This study was carried out in two phases. The objective of the first phase was to identify a cost-effective means of monitoring traffic within a rural, mountainous stretch of the I-70 freeway. An algorithm was developed to estimate average link speed, travel time and the standard error of estimates to provide user information on the reliability of the estimates based on the probe data. The algorithm was tested for different traffic conditions and geometric characteristics of links. In the second phase of the project, a real-time demonstrational prototype was developed to receive, process and estimate link travel time and speed statistics in real-time. The system was tested off-line and on-line based on field data received from the I-70 corridor. In addition, GPS receivers were deployed using a commercial vanpool service and the system was evaluated further.

Author: Ahmad Ardani
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 186

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Book Description
This report presents a 5-year evaluation and construction details of nine test sections with varying textural characteristics. Included in the report is an overview of the methodologies used to texture concrete pavement surfaces and a discussion of frictional attributes of various textures at different speeds and their impact on noise properties. Also included in the report are descriptions of texture-measuring devices and texture-installing equipment, a description of the state-of-the-art equipment used to acquire sound pressure levels, plus a thorough discussion of data acquisition/analysis. Frictional characteristics of the individual test sections were evaluated using the ASTM E 274 skid testing procedure.

Author: Bud A. Brakey
Publisher:
ISBN:
Category : Pavements, Bituminous
Languages : en
Pages : 60

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Author: George Annandale
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 62

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Book Description
This report explains the use of the Erodibility Index Method (also known as Annandale's Method) to calculate bridge pier scour. The method can be used to predict scour in any earth material, including rock and cohesive and noncohesive soils. Earth material properties are represented by a geo-mechanical index that integrates the role of material mass strength, block/particle size, internal shear strength and orientation in quantifying the relative ability of earth material to resist scour. A relationship between the geo-mechanical index and the erosive power of water defines the scour threshold that is used in the scour calculations. By comparing the erosive power that is required to scour an earth material (obtained from the threshold relationship) with the erosive power that is available at the base of a bridge pier, it is possible to calculate scour depth. The report outlines the methods that are used to quantify the geo-mechanical index and those that are used to estimate the erosive power of water flowing around bridge piers, and explains how to calculate scour depth. Application of the method is illustrated with an example.

Author: Yunping Xi
Publisher:
ISBN:
Category : Concrete bridges
Languages : en
Pages : 166

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Book Description
Corrosion of reinforced concrete structures has been a significant problem for many state and transportation agencies since the application of deicing salts was introduced. Much research has been conducted to develop corrosion protection systems that can prolong the life span of reinforced concrete structures. The Colorado Department of Transportation (CDOT) has several routine and experimental measures to prevent corrosion of the rebar including epoxy-coated rebar, calcium nitrite admixture, organic corrosion inhibitors, a thick cover of quality concrete, and a waterproofing membrane covered by an asphalt overlay. An extensive literature review was performed to collect information on various corrosion protection systems that have been used in the U.S. and around the world. Current CDOT practices in terms of corrosion protection measures were reviewed. A draft inspection plan for Colorado's bridge structures was proposed.

Author: Porter K. Wheeler
Publisher:
ISBN:
Category : Public-private sector cooperation
Languages : en
Pages : 130

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Book Description
This report assesses the current Public-Private Initiatives (PPI) program from the perspective of all participants and incorporates best practices from other states. Section 2 summarizes innovative finance. The current PPI program and processes are reviewed in section 3. In section 4 the best practices of selected PPI programs in other states and jurisdictions are examined. In section 5 the recommendations for the Colorado Department of Transportation's considerations are presented in the key areas of policy/legal, process, and management.