Performance-related Specifications for Highway Construction and Rehabilitation
Performance-related Specifications for Highway Construction and Rehabilitation

Author: William P. Chamberlin

Publisher: Transportation Research Board

Published: 1995

Total Pages: 60

ISBN-13: 9780309056731

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This synthesis will be of interest to administrators, including contract and specifications administrators; research, construction, materials, specification, and design engineers; agency project managers and staff; and highway construction contractors. It describes the state of the practice with respect to the development and present status of performance-related specifications (PRS) for highway materials and construction. This report of the Transportation Research Board summarizes the historical events that have prompted U.S. interest in PRS development and describes the underlying concepts. In addition, it describes current practice with regard to PRS implementation and refers to the principal PRS literature with emphasis on performance and cost models. It emphasizes the utility of PRS in providing objective/ rational measures that can be used for special contract conditions, such as incentive or disincentive adjustments.

Improved Specifications for Hydraulic Cement Concrete
Improved Specifications for Hydraulic Cement Concrete

Author: Woodrow J. Halstead

Publisher:

Published: 1983

Total Pages: 128

ISBN-13:

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This is the final report of a study of the application of statistical concepts to specifications for hydraulic cement concrete as used in highway facilities. It reviews the general problems associated with the application of statistical techniques to hydraulic cement concrete, and discusses the potential advantages and disadvantages to applying such techniques to concrete used in the construction of transportation facilities. During the course of the research reported here, it was found that for the Virginia Department of Highways and Transportation, contracts for concrete structures generally involved small volumes of concrete, and that the usual frequency of sampling and testing did not provide sufficient test results for establishing specifications based on usually recommended risks to both the contractor and the state. Increases in the frequency of testing to provide the recommended risks would result in excessive increases in costs. Accordingly, procedures for acceptance of concrete on the basis of small-to-medium sample sizes at increased statistical risks, but based on sound engineering judgment, were developed and are included in the report. Also included are complete recommendations for a revised specification for hydraulic cement concrete and a discussion of the statistical significance of the recommended changes. Recommended revisions to the Virginia Test Manual and the Instructions to concrete inspectors that would be needed should the revised specification be accepted are included in the appendices. Also included as an appendix is a resume of practices and requirements in other states using statistical concepts in their specifications for hydraulic cement concrete.

End-result Specifications for Hydraulic Cement Concrete
End-result Specifications for Hydraulic Cement Concrete

Author: Hamdi Celik Ozyildirim

Publisher:

Published: 2011

Total Pages: 34

ISBN-13:

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A study was undertaken to develop an end-result specification (ERS) for hydraulic cement concrete to be used by the Virginia Department of Transportation (VDOT) in transportation structures to obtain a uniform, consistent, quality product. The study was done in two phases. In the Phase I study, an ERS special provision was developed and applied to two pilot bridge projects, one each in two of VDOT's nine districts. In the current Phase II study, the ERS special provision developed in Phase I was updated and applied to more projects: of VDOT's nine districts, eight provided strength and permeability data for Class A3 concrete, eight provided strength data for Class A4 concrete, and seven provided permeability data for Class A4 concretes for bridge structures. Two paving projects were also included. The study addressed sampling, testing, quality characteristics, specification limits, bridge and paving concretes, and pay factors. VDOT's current specifications were applied for acceptance and rejection of all pilot projects, and pay adjustments were not applied. VDOT's ERS has three parts. The first part covers process control measures. The contractor is responsible for the concrete design and is required to provide a quality control plan. The plan addresses all elements that affect quality, including mixture designs, aggregate sources, ingredients, tests and testing frequency, fresh and hardened concrete properties, and control charts. The second part covers the mixture design approval by VDOT. The third part covers project acceptance, which includes pay adjustments depending on the results of tests conducted under the first part. In the current study, the first two parts of the ERS were well received and enabled innovations, minimized waste of materials, and provided green initiatives by reducing cement consumption. The third part dealing with pay adjustments had strong opposition from the industry and needs further evaluation. Thus, the study recommends that the first two parts of the ERS be implemented for use with bridge structures and the third part be deferred until more projects are evaluated. In addition, pilot projects for pavements should be initiated as was done for bridges. A new, single class of concrete for both decks and substructures is planned for bridges that will provide the same highquality concrete throughout the structure. This new class of concrete will enable more samples for ERS testing since there will not be more than one type of concrete in the structure. Projects with this new type of concrete should be included in further pilot tests of VDO's ERS.

Performance Based Specifications Final Report
Performance Based Specifications Final Report

Author: James K. Cable

Publisher:

Published: 1998

Total Pages: 32

ISBN-13:

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The goal in highway construction and operation has shifted from method based specifications to specifications relating desired performance attributes to materials, mix designs, and construction methods. Shifting from method specifications to performance based specifications can work as an incentive or disincentive for the contractor to improve performance or extend pavement life. This literature search was directed at a review of existing portland cement concrete performance specification development, and the criteria that can effectively measure pavement performance. The criteria identified in the literature include concrete strength, slab thickness, air content, initial smoothness, water-cement ratio, unit weight, and slump. A description of each criterion, along with the advantages, disadvantages, and test methods for each are identified. Also included are the results from a survey that was sent out to various state, federal, and trade agencies. The responses indicated that 53% currently use or are developing a performance based specification program. Of the 47% of agencies that do not use a performance based specification program, over 34% indicated that they would consider a similar program. The most commonly measured characteristics include thickness, strength, smoothness, and air content. Lastly recommendations and conclusions are made regarding other factors that affect pavement performance and a proposed second phase of the research is suggested. The research team suggests that a regional expert task group be formed to identify performance levels and criteria. The results of that effort will guide the research team in the development of new or revised specifications.