THE EFFECT OF WEATHER CONDITIONS ON EARLY STRAIN IN CONCRETE SLABS

CRACK SURVEYS OF CONCRETE ROADS HAVE SHOWN THAT WEATHER CONDITIONS AT THE TIME OF PLACING THE CONCRETE CAN HAVE A CONSIDERABLE INFLUENCE ON THE AMOUNT OF TRANSVERSE CRACKING OBSERVED AFTER A FEW YEARS. AN EXPERIMENT TO MEASURE THE EARLY STRAINS IN PILOT-SCALE SLABS IN ORDER TO DETERMINE WHICH OF THE ENVIRONMENTAL CONDITIONS AT THE TIME OF CONSTRUCTION WAS MOST CLOSELY RELATED TO THE POTENTIAL PERFORMANCE OF THE SLABS IS DESCRIBED. FOR AN INDIVIDUAL SLAB, THE ENVIRONMENTAL PARAMETER FOUND TO BE MOST SIGNIFICANTLY CORRELATED WITH SLAB STRAIN WAS THE TEMPERATURE GRADIENT IN THE CONCRETE. IT WAS FOUND THAT CRACKING WAS LIKELY TO BE INITIATED WHEN THE TEMPERATURE GRADIENT IN A SLAB CHANGED BY MORE 0.07 C/MM FROM THE TIME OF SET, A CONDITION WHICH WAS REACHED IN THESE EXPERIMENTS WHEN THE MAXIMUM SLAB TEMPERATURE WAS GREATER THAN 28 C AND THE MAXIMUM AIR TEMPERATURE WAS GREATER THAN 24 C. WHEN HIGH AIR TEMPERATURES PREVAIL DURING CONSTRUCTION, PRECAUTIONS SHOULD THEREFORE BE TAKEN TO ENSURE THAT CHANGES OF TEMPERATURE GRADIENT WITHIN THE CONCRETE ARE KEPT BELOW 0.07 C/MM FOR THE FIRST TWO OR THREE BY SUITABLE CURING TECHNIQUES. /AUTHOR/

  • Supplemental Notes:
    • Rrp Rept Lr 266, 6 PP, 6 FIG, 11 TAB
  • Corporate Authors:

    Road Research Laboratory /UK

    ,    
  • Authors:
    • Franklin, R E
  • Publication Date: 1969

Subject/Index Terms

Filing Info

  • Accession Number: 00213430
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 16 1970 12:00AM