Author: Mohamad Nagi Publisher: Transportation Research Board ISBN: 0309098890 Category : Air-entrained concrete Languages : en Pages : 60
Book Description
"This report presents a recommended procedure for evaluating air-entraining admixtures used in highway concrete. The procedure involves the testing of non-air-entrained concrete and concrete containing the air-entraining admixture under simulated field conditions. Criteria are proposed for acceptance of admixtures for use in either highway pavements or structures. The recommended procedure and acceptance criteria will guide materials engineers in evaluating and selecting air-entraining admixtures that should contribute to appropriate freeze-thaw durability and thus to good performance and long service life. The content of the report will be of immediate interest to materials engineers, researchers, and others concerned with the design of concrete mixtures for use in highway pavements and structures."--taken from Foreword, page [v].
Author: Lawrence L. Sutter Publisher: Transportation Research Board ISBN: 0309283558 Category : Political Science Languages : en Pages : 91
Book Description
"TRB's National Cooperative Highway Research Program (NCHRP) 749: Methods for Evaluating Fly Ash for Use in Highway Concrete presents suggested changes to coal fly ash specifications and test protocols contained in American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Transportation Materials and Methods of Sampling and Testing (AASHTO M 295). The changes suggested include modifications to the test methods currently specified for evaluating acceptability of fly ash for use in highway concrete as well as the introduction of new test methods for enhancing such evaluations. Attachment C: Details of the Research into Methods for Evaluating Fly Ash Use in Highway Concrete is only available online."--Publisher description.
Author: Publisher: ISBN: Category : Concrete Languages : en Pages : 230
Book Description
This study evaluated the impacts of construction on the air content and air-void system structure of Portland cement concrete pavements. The primary intent was to quantify the air content of fresh concrete before and after it has gone through the slipform paver. The air-void system parameters of hardened concrete were then assessed using cast and extracted core specimens. The results of the air content testing on fresh concrete and the concrete cylinder specimens cast in the field suggested that there is some loss of air as the concrete passes through the paver. Laboratory testing performed on cores extracted from the pavement did not provide any conclusive evidence that entrained air is lost during the slipform paving process. In fact, many of the extracted cores had measured air content values that were much higher than the specification requirement. If excessive, this could result in increased permeability and low-strength related issues. Although a rigorous statistical analysis was not performed, the results suggest that the air content testing on fresh concrete is not capturing the true air content of the concrete placed with a slipform paver. The fresh concrete air content is generally lower than the air content measured in the cores.
Author: Mohamad Nagi
Author: Construction Technology Laboratories (Portland Cement Association)
Author: Construction Technology Laboratories (Portland Cement Association)
Author: United States. Central Concrete Laboratory, Mount Vernon, N.Y.
Author: Lawrence L. Sutter
Author: 
Author: National Research Council (U.S.). Highway Research Board
Author: 
Author: C. H. Best
Author: