Influence of aggregate granulometry on air content in concrete mixture and freezing-thawing resistance of concrete

摘要

Concrete frost resistance is one of the main factors that effects its durability. This is particularly important in the harsh climate regions where the water in concrete pores gets multiple freeze-thaw cycles. Concrete frost resistance can be increased by changing the coarse aggregate content by volume in the concrete mixture, as it is changing aad concrete porosity. It was found that coarse aggregate volume concentration increase has a negative effect on predicted freezing-thawing resistance of concrete. It was found the correlation between a closed porosity of concrete, coarse aggregate volumetric concentration, air content in the concrete mixture and the predicted frost resistance of concrete. After statistical processing of test results it was found significant dependencies between coarse aggregate volumetric concentration in concrete, its closed porosity and predicted concrete freezing — thawing resistance and durability of concrete.