Download or read book Improved Specifications for Hydraulic Cement Concrete written by Woodrow J. Halstead and published by . This book was released on 1983 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Pilot Study of Proposed Revisions to Specifications for Hydraulic Cement Concrete written by Woodrow J. Halstead and published by . This book was released on 1985 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the results of a pilot study of the statistical acceptance procedures proposed for adoption by the Virginia Department of Highways and Transportation. The proposed procedures were recommended in the report titled "Improved Specifications for Hydraulic Cement Concrete" and issued in 1983. This study revealed that practical difficulties would likely be encountered if the initially proposed revisions were adopted. Major problems were noted with the proposed system of random sampling based on a predetermined truckload of material, the definition of the total concrete placed on the contract as a single lot, the initially proposed requirement for average entrained air content, and the present practice of accepting concrete on the basis of its having 85% of the required 28-day strength at 14 days. After study of the findings, a revised proposal has been made for introducing such concepts into the Department's specifications for hydraulic cement concrete. The proposal is that a day's production of hydraulic cement concrete be considered a lot and that three samples per lot normally be taken for judging acceptability. The proper parameters for judging acceptance are based on a computerized statistical program (non-central-t) developed by the New Jersey Department of Transportation. These are discussed in the report and are recommended for adoption by the Virginia Department of Highways and Transportation. Where conditions warrant, a larger number of samples per day may be required with consequent reductions in the risks of accepting poor concrete.
Download or read book End result Specifications for Hydraulic Cement Concrete written by Hamdi Celik Ozyildirim and published by . This book was released on 2011 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Report on Testing Hydraulic Cement written by United States. Army. Corps of Engineers and published by . This book was released on 1901 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book User s Guide to ASTM Specification C94 on Ready Mixed Concrete written by and published by ASTM International. This book was released on with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Treatise on Cement Specifications written by Jerome Cochran and published by . This book was released on 1912 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Specifications for Hydraulic Cement Concrete written by Woodrow J. Halstead and published by . This book was released on 1983 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Engineered Concrete Mix Design and Test Methods written by Irving Kett and published by CRC Press. This book was released on 1999-11-29 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Romans used an early type of concrete made with natural pozzuolanic cement more than 2,000 years ago. Today, Portland Cement Concrete is the most important material of construction. Yet few books, if any, exist that offer an in-depth analysis of the mixing and testing methods of this vital hydraulic cement. Until now that is. Engineered Concrete: Mix Design and Test Methods helps engineers, as well as laboratory technicians, grasp a better understanding of Portland Cement and Portland Cement Concrete. The book is divided into several sections, with the first, Mix Design Procedures, explaining how concrete batches are designed, mixed, and measured for various consistencies. Another section details the tests of the primary component materials of concrete other than water - namely Portland Cement, aggregates, and mortar - while the final section includes some of the fundamental concrete testing procedures for different strength parameters in conformity with the standards of the American Society for Testing Materials. While focusing solely on Portland Cement, the book also includes information on other hydraulic cementitious materials and additives because of their modern applications. Solidly researched and written, Engineered Concrete: Mix Design and Test Methods provides a clear understanding of mix design and testing of Portland Cement Concrete. As every civil engineer knows, it is the most versatile and important material of construction, and will probably remain so as far into the future as we can see.
Download or read book Hydraulic Cement written by Frederick Putnam Spalding and published by . This book was released on 1906 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Quest for Performance related Specifications for Hydraulic Cement Concrete written by Woodrow J. Halstead and published by . This book was released on 1982 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper reviews some of the problems associated with quality assurance for hydraulic cement concrete and the difficulties of relating the results of quality control and acceptance testing to the performance of the concrete facility. The importance of good control procedures and inspection of concrete placement by persons knowledgeable in concrete technology is stressed. Also, it is concluded that acceptance procedures based on statistical probabilities are a first step towards attaining the ultimate goal of specification requirements optimally related to performance. The major problem in this area is identified as one of obtaining sufficient test data to establish an acceptable degree of confidence that the quality of the concrete is as indicated by probability theory. Because of the time and expense of most acceptance tests, particularly strength tests, decisions must be based on limited data. The report summarizes the specifications of other agencies utilizing statistical probabilities and the recommendations of the American Concrete Institute concerning acceptable strengths. Finally, an evaluation is made of the technique most applicable to the Virginia Department of Highways and Transportation, and specific recommendations are made for changes in the Department's specifications. It is recommended that the revised specification be evaluated by simulated applications to several construction projects.
Download or read book Polymer modified Hydraulic cement Mixtures written by Louis A. Kuhlmann and published by ASTM International. This book was released on 1993 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dozen papers from a June 1992 symposium in Louisville, Kentucky review the current use of organic polymers dispersed in water and formulated to add to portland cement. One sets out the status of ASTM's forthcoming specification and test methods. Others discuss such aspects as solid grade acrylic c
Download or read book Concrete Materials written by Sandor Popovics and published by William Andrew. This book was released on 1992-12-31 with total page 675 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an in-depth approach to concrete ingredients and their relationships to concrete by discussing their properties, pertinent test methods, specifications, proper use and selection, and solutions to problems in practice. The approach is practice oriented, and the book assists in the improved application of concrete through a thorough understanding of its ingredients. This is aided by the discussion of certain fundamental aspects and relationships in quantitative forms, and by also presenting the interpretation of research and experience. An extensive bibliography is included. The book is a current, organized summary of knowledge concerning concrete-making materials, which will enable the engineer/user to make the best possible product using these materials.
Download or read book End result Specification for Hydraulic Cement Concrete written by Charles S. Hughes and published by . This book was released on 2005 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research was to develop and implement an end-result specification (ERS) for hydraulic cement concrete for structural and paving use. This report details the development of the specification, in the form of a special provision, including the decisions that went into the choice of quality characteristics to be measured and the selection of items on which pay factors were to be based. It also shows and discusses the results of a simulation effort to determine pay factors under actual construction conditions that used the traditional specification. Finally, it includes data from two pilot bridge projects that used the special provision.. Further evaluation of the ERS is recommended to address outstanding issues on lot size, testing, quality characteristics, selection of limits, and pay factors. The implementation of an ERS would lead to innovations and higher quality concrete in the finished product that, in turn, would result in longer lasting structures with minimal maintenance. If as little as a 5 percent increase in the service life were achieved, the savings would be in the millions of dollars. In addition, in cases of dispute, an ERS is more defensible than is a method specification.
Download or read book General Specifications for Concrete and Reinforced Concrete written by Jerome Cochran and published by . This book was released on 1913 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Standard Performance Specification for Hydraulic Cement written by American Society for Testing Materials. Committee C-1 on Cement and published by . This book was released on 2010 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Related Specifications for Hydraulic Cement Concrete Used in Construction and Rehabilitation of Ground Transportation Facilities written by Woodrow J. Halstead and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the work performed on the subject study from June through September 1982. In accordance with the revised work plan for Task 4 of the project approved May 24, 1982, the new completion date for the project is April 30, 1983.
Download or read book Standard Specification for Expansive Hydraulic Cement written by and published by . This book was released on with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
