Sustained Load Deflection of High Strength Concrete Beams
{'Code': '07030000', 'Directorate': {'LongName': 'Directorate For Engineering'}, 'Division': {'LongName': 'Div Of Civil, Mechanical, & Manufact Inn'}}
{'SignBlockName': 'William Hakala'}
Rapid growth interest in use of high strength concrete (compressive             strength to about 12,000 psi) has caused concern that current design            methods and codified procedures for design may not be appropriate.  Many        design equations found in the 1983 Building Code of the American                Concrete Institute, governing most US practice, are based on tests of           members using concrete strength not greater than 6000 psi.  A nine-year         program of research on high strength concrete at Cornell had three              objectives:  (a) to provide an understanding of the basic differences in        behavior of the material, (b) to establish the engineering properties of        the material, and (c) to study the behavior of reinforced concrete              members made using the material.  One of the more significant                   observations is that the creep coefficient for high strength concrete.          Present Code procedures for design do not account for this.  The point          is of particular importance, because short- and long-term deflections           may prove to be a governing aspect of design for slender members made           using the material.  This project is for further  testing of beams under        sustained loading, to study immediate and time-dependent deflections,           crack growth, and internal force redistributions.  Important variables          include time, compressive strength, age at first loading, and the amount        of tensile and compressive reinforcing steel.                                                                                                                   Results of the proposed research should help improve the implementation         and increased use of high strength concrete in structures such as               buildings and bridges.
{'FirstName': 'Arthur', 'LastName': 'Nilson', 'EmailAddress': None, 'StartDate': '02/15/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Cornell University', 'CityName': 'Ithaca', 'ZipCode': '148502820', 'PhoneNumber': '6072555014', 'StreetAddress': '373 Pine Tree Road', 'CountryName': 'United States', 'StateName': 'New York', 'StateCode': 'NY'}
{'Code': '1442', 'Text': 'CONSTRUCTION AND INFRASTRUCTUR'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1986&All=true', 'xml': '8614220.xml'}