Portland-cement concrete rheology and workability : final report.

8233061292011final report; Oct. 1996-May 1999.Forster, StephenPDFTech ReportFHWA-RD-00-025;ERDC-TR-S-XX-00DTFH61-96-Y-30076Portland cement concreteRheological propertiesRheologyVibratory equipmentWorkabilityShear rateConcreteRheologyWorkabilityMississippiTurner-Fairbank Highway Research CenterWong, G. SamAlexander, A. MichelHaskins, RichardPoole, Toy S.Malone, Phillip G.Wakeley, LillianEngineer Research and Development Center (U.S.). Structures LaboratoryUnited States. Federal Highway Administration. Office of Infrastructure Research and DevelopmentNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceFederal Highway AdministrationMethods for determining the workability of freshly mixed Portland-cement concrete withslumps less than 5 1 mm (2 in) were investigated. Four potential methods to determine theworkability of concrete were proposed for evaluation and development. The methods includedtwo moving-object methods, one free-orifice method, and a vibrating-slope method. Thereport outlines modifications to these existing techniques and equipment to permit themeasurement of rheological properties at two or more shear rates. The vibrating-slopeapparatus (VSA) was selected for further development. (Questions about this report should beaddressed to Dr. Paul F. Mlakar, Sr., Chief, Concrete and Materials Division, or Mr. G. SamWong, Research Geologist, ERDC, Structures Laboratory.