Examining the possibility to estimate the influence of admixtures on pore structure of self-compacting concrete using the air void analyzer

摘要

The relationships between pressure methods of measuring air content in fresh concrete and measurements of air-void system parameters using the Air Void Analyzer (AVA) for fresh self-compacting concrete (SCC) and high performance self-compacting concrete (HPSCC) made with two different superplasticizer (SP) type, air-entraining admixture (AEA), viscosity modifying admixture (VMA) and anti-foaming admixture (AFA) is examined in the paper. The air content, size distribution, specific surface, and spacing factor of concrete mixtures were tested. The results indicated that the admixtures significantly affect the porosity of SCC and HPSCC. The correlation between the AVA tests and the porosity of hardened SCC and HPSCC tests (EN 480-11) was investigated also. The research results showed that fluidity of fresh concrete mixture significantly affect the reliability of the measurement using AVA.