AUTOMATION OF SHRINKAGE TESTING
PRESENT SHRINKAGE TEST PROCEDURES ARE TIME-AND-LABOR CONSUMING. AN AUTOMATIC SYSTEM OF MEASURING AND RECORDING A LARGE NUMBER OF CONCRETE SAMPLES OVER A LONG PERIOD IS DESCRIBED. INDUCTION STRAIN GAUGES ARE SUFFICIENTLY ACCURATE TO RECORD SLOW MOVEMENTS OVER SEVERAL MONTHS. A DESCRIPTION IS GIVEN OF THE DEVICE WHICH RECORDS THE SIGNALS OF 96 STRAIN GAUGES. THE SIGNALS ARE MEASURED BY MEANS OF A POTENTIOMETRIC MILLIVOLTMETER AND THE NUMERICAL VALUE IS RECORDED ON A PUNCHED TAPE AT REGULAR INTERVALS PER HOUR OR PER DAY. THE EXPERIMENTAL OUTPUT OF THE SYSTEM WAS EVALUATED WITH REGARD TO ITS PRECISION AND ACCURACY. AFTER SIX MONTHS OF DRYING AT 20 DEGREES C (RELATIVE HUMIDITY 65 PER CENT), THE EFFECT ON SHRINKAGE OF MINOR FACTORS SUCH AS CASTING, CURING AND NUMBER OF SAMPLES IN A GROUP WAS INVESTIGATED IN ORDER TO STANDARDIZE THOSE FACTORS FOR LATER STUDIES. MEASURES TAKEN FOR REDUCING RESULT VARIABILITY ARE OUTLINED, AND SUGGESTIONS MADE FOR IMPROVING PROCEDURES AND EQUIPMENT. WORK CONTINUES ON THE EFFECT ON SHRINKAGE OF REDUCTION IN SAMPLE SIZES. /LCPC(A)/RRL/
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Supplemental Notes:
- Vol 1, No 1-E, 22 PP, 4 FIG, 2 PHOT, 5 REF
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Authors:
- Mears, A R
- Publication Date: 1968-3
Media Info
Subject/Index Terms
- TRT Terms: Automation; Concrete; Measurement; Potentiometers; Recording instruments; Shrinkage; Statistical sampling; Voltmeters
- Uncontrolled Terms: Sample size
- Old TRIS Terms: Recorders; Shrinkage tests
- Subject Areas: Data and Information Technology; Highways; Materials;
Filing Info
- Accession Number: 00213045
- Record Type: Publication
- Source Agency: Road Research Laboratory /UK
- Files: TRIS
- Created Date: May 16 1971 12:00AM