Practical Considerations Pertaining to the Microscopical Determination of Air Void Characteristics of Hardened Concrete (ASTM C 457 Standard)
1990; ASM International; Volume: 12; Issue: 1 Linguagem: Inglês
10.1520/cca10383j
ISSN1945-7561
AutoresRichard Pleau, Pierre Plante, R. Gagné, M. Pigeon,
Tópico(s)Fire effects on concrete materials
ResumoAbstract Many parameters affecting the quality of the air void characteristics measurement are reviewed and discussed. The difficulties more frequently encountered during the measurement process are described, and some simple rules are proposed in order to increase, as much as possible, the accuracy and reproducibility of the test. The influence of the sampling size is studied, and the variability of air content, specific surface, and spacing factor is estimated from a statistical analysis of about 600 different concrete mixtures. The influence of the operator's subjectivity is also investigated, and the effect produced by large air voids on the computation of the spacing factor is discussed.
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