CREEP RECOVERY AND CREEP OF PRESHRUNK CONCRETE

THIS REPORT PRESENTS THE ANALYSIS OF A LABORATORY INVESTIGATION OF CONCRETE SPECIMENS SUBJECTED TO CREEP TESTS. IT WAS A CONTINUATION STUDY OF A COOPERATIVE RESEARCH PROGRAM, STUDY OF THE EFFECT OF CREEP AND SHRINKAGE ON THE DEFLECTION OF REINFORCED CONCRETE BRIDGES. CHANGES IN CREEP, APPARENT STRAIN, AND MODULAS OF ELASTICITY WERE DETERMINED FOR PRISM SPECIMENS WHICH HAD BEEN UNDER AXIAL COMPRESSIVE LOADS FOR ABOUT THREE YEARS AND WERE THEN UNLODDED AND RELOADED. PRISMS WHICH HAD BEEN DRYING FOR ABOUT THREE YEARS, AND WERE ESSENTIALLY PRESHRUNK, WERE CREEP TESTED. ALSO THE EFFECT OF TIME, CONSTITUENTS, AND ENVIRONMENT ON THE ELASTIC MODULUS AND STRENGTH OF CONCRETE WERE STUDIED. THE CREEP RECOVDRY BEHAVIOR FOR THE SPECIMENS IN THIS STUDY WAS CONSIDERABLE DIFFERENT FROM THAT PREVIOUSLY REPORTED FOR SPECIMENS LOADED FOR A SHORTER PERIOD OF TIME. FROM THIS STUDY IT APPEARS THAT THE MAGNITUDE OF CREEP RECOVERY MAY BE RELATED TO THE LENGTH OF TIME WHICH THE SPECIMENT HAS BEEN UNDER SUSTAINED LOAD. SIMILARLY IT WAS FOUND THAT THE BASIC, OR VISCOUS, CREEP APPEARS TO BE A FUNCTION OF THE AGE AT THE TIME OF LOADING. FINALLY IT WAS FOUND THAT FOR THE SIZE OF SPECIMEN USED, BOTH THE ELASTIC MODULUS AND THE ULTIMATE COMPRESSIVE STRENGTH OF THE CONCRETE GENERALLY DECREASES WITH TIME FROM THE VALUES OBTAINED AT 28 DAYS AFTER CASTING. /BPR/

• Record URL:
  • https://hdl.handle.net/10355/100314
• 
• Supplemental Notes:
  • Bpr-8, Mhd 60-8. The Preliminary Report is available at: [https://spexternal.modot.mo.gov/sites/cm/CORDT/MCHRP67-3A.pdf]
• Corporate Authors:

  University of Missouri, Columbia

  1205 University Avenue
  Columbia, MO  United States  65201

  Missouri State Highway Commission

  State Highway Building
  Jefferson City, MO  United States  65101
• Authors:
  • Hollrah, R L
  • Buettner, D R
• Publication Date: 1966-6

Subject/Index Terms

• TRT Terms: Age; Axial loads; Compression; Concrete; Creep; Laboratory studies; Mechanical relaxation; Mechanical strain; Modulus of elasticity; Shrinkage; Specimens; Testing; Time
• Uncontrolled Terms: Strain rate
• Old TRIS Terms: Preshrunk concrete
• Subject Areas: Bridges and other structures; Highways; Materials;

Filing Info

• Accession Number: 00211998
• Record Type: Publication
• Source Agency: Bureau of Public Roads /US
• Files: TRIS, STATEDOT
• Created Date: Oct 1 1994 12:00AM