CONCRETE STRENGTH DURING CONSTRUCTION
The early strength gain characteristics of a concrete at various temperatures was investigated in this study. In addition, the applicability of two widely known nondestructive evaluation methods were examined for the purpose of determining the compressive strength of concrete at early ages. For destructive evaluation, standard cylinder compression tests, splitting tensile tests and pull-out tests were made on specimens cured at 73F, 55F and 35F. For non-destructive evaluation, both probe penetration and rebound hammer tests were performed on slabs. Tests were carried out at the age of 1, 2, 3, 5, 7, 14, 28 and 42 days after casting the concrete. The results show that when related to maturity, the rate of increase in the splitting tensile strength is about the same as that of the compressive strength, whereas the rate of increase in the pull-out strength and the modulus are slightly greater than that of the compressive strength. The results of non-destructive evaluations revealed that the compressive strength could not be estimated correctly by the probe method using the manufacturer's conversion charts. Because of lower rebound readings, the rebound hammer could not be used to estimate the compressive strength at early ages.
National Bureau of StandardsCenter for Building Technology
Gaithersburg, MD United States 20760
- Lew, H S
- Reichard, T W
- Clifton, J R
- Publication Date: 1976-12
- Pagination: 60 p.
- TRT Terms: Building; Compression tests; Compressive strength; Concrete placing; Concrete structures; Construction; Mechanical properties; Mechanical tests; Modulus; Modulus of elasticity; Nondestructive tests; Performance tests; Probes (Measuring devices); Pull out test; Rebound; Temperature; Tensile properties; Tension tests
- Uncontrolled Terms: Destructive testing
- Old TRIS Terms: Hammering; Probing; Tensile test
- Subject Areas: Construction; Highways; Materials;
- Accession Number: 00151592
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: NBS-TN-932 Intrm Rpt.
- Files: TRIS
- Created Date: Apr 13 1977 12:00AM