STUDIES OF THE ACCELERATED AIRING OF CONCRETE TEST SPECIMENS
CONCRETE IS NORMALLY SPECIFIED IN TERMS OF ITS 28-DAY STRENGTH, BUT IT WOULD BE AN ADVANTAGE TO PREDICT, WITHIN A SHORT TIME OF ITS BEING MIXED, ITS LIKELIHOOD TO REACH THE SPECIFIED STRENGTH AT 28 DAYS. SUCH KNOWLEDGE WOULD ALLOW ANY DEFECTIVE CONCRETE TO BE CUT OUT WHILE IT IS STILL WEAK OR BEFORE IT IS COVERED BY SUBSEQUENT CONSTRUCTION. IT WOULD THEN BE POSSIBLE TO OBTAIN BETTER CONTROL OF THE CONCRETE PRODUCTION AND HENCE A MORE ECONOMICAL CONCRETE. AN ACCELERATED CURING METHOD HAS BEEN PROPOSED AND DISCUSSED BY THE INSTITUTION OF CIVIL ENGINEERS AND IS GENERALLY ACCEPTED BUT THERE ARE SOME DOUBTS AS TO WHETHER THE RIGID TIME LIMITS SPECIFIED WOULD BE OPERABLE UNDER VARIOUS CONDITIONS ON CONSTRUCTION SITES. THIS TEST THEREFORE IS STUDIED IN DETAIL TO MODIFY THE TIME-SCALE OF THE CURING REGIME SO THAT IT IS ACCEPTABLE UNDER ALL SITE CONDITIONS. PROPOSALS ARE MADE FOR ALLOWING THE SPECIMENS TO STAND FOR 1 - 3 HOURS BEFORE COMMENCING THE ACCELERATED CURING CYCLE, AND AFTERWARDS TO COOL IN WATER FOR 1 - 2 HOURS BEFORE TESTING. THE CURING PERIOD IS REDUCED TO 20 HOURS TO ACCOMMODATE THESE PRE-CURING AND POST-CURING PERIODS WITHIN A CYCLE OF NOMINALLY 24 HOURS. IT IS SHOWN THAT, FOR A WIDE RANGE OF AGGREGATES AND ORDINARY PORTLAND CEMENTS, THE DIFFERENCE IN CONCRETE STRENGTHS CAUSED BY USING THE EXTREMES OF THE TIME TOLERANCES BEFORE AND AFTER ACCELERATED CURING IS LESS THAN THAT OBTAINED FOR THE EXTREMES OF THE TIME TOLERANCES OF THE ICE TEST. /RRL(A)/
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Supplemental Notes:
- Rrl Rept Lr 364, 21 PP, 5 FIG, 6 TAB, 1 PHOT, 14 REF
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Authors:
- CORNELIUS, D F
- Franklin, R E
- Publication Date: 1970
Media Info
Subject/Index Terms
- TRT Terms: Accelerating agents; Atmospheric circulation; Concrete; Concrete curing; Concrete tests; Strength of materials; Time
- Old TRIS Terms: Accelerating (Process); Time effects
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 00213130
- Record Type: Publication
- Source Agency: Road Research Laboratory /UK
- Files: TRIS
- Created Date: Jun 1 1971 12:00AM