Effect of aggregate origin on freeze/thaw resistance of self-compacting concrete with and without a de-icing agent

Abstract

Freezing and thawing cycles, with or without de-icing agents, are the principal causes of concrete structure degradation during the winter. This paper explores the effects of aggregate type on the level of degradation of self-compacting concrete (SCC) due to freeze-thaw (f/t) action. Natural river (NRA) and/or natural crushed (NCA) aggregate, as well as the recycled aggregate of known (RCA-N) and unknown provenance (RCA-A), were employed to produce six different SCC mixtures. The temperature, density, air content, and consistency were determined for fresh concrete, while compressive strength, water absorption by gradual immersion and vacuuming, and frost resistance with and without de-icing salts were tested for hardened concrete. Even though all tested concretes have met the criteria for frost resistance with and without the de-icing salts, it was found that the type of aggregate has a noticeable influence on it. The type of natural aggregate has little effect on SCC frost resistance, but it does influence its behavior when frost and salt are present at the same time. In f/t conditions, RCA-N can be used the same way as natural aggregate, while RCA-A causes the biggest frost resistance reduction. However, both RCAs are not recommended for application in conditions of simultaneous frost and salt impacts.

Keywords

• self-compacting concrete
• natural aggregate
• recycled concrete aggregate
• water absorption
• freeze/thaw resistance
• freeze-thaw resistance with de-icing agent