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Basic Research on Frost Resistance of LPC-FA Concrete Placed in Chloride Environment

S. Kawamorita and K. Niwase
National Institute of Technology Hachinohe College, Hachinohe Aomori, Japan

Abstract—In cold regions in the world, the deterioration of a concrete such as scaling and pop-out is caused by freezing and thawing action. Furthermore, the compounding with salt damage, carbonation and the like has a major influence on the durability and the appearance of the concrete structure. Deterioration resistance generally improves with densification. In this study, we evaluated the frost damage resistance of concrete using low heat portland cement and fly ash (LPC-FA concrete). In the compounding in which the strength property and the air voids structure change with the material age, it conducted various tests. As a result of compressive strength, it was confirmed that it had sufficient strength regardless of W/B and air. Although the exposed specimens were subjected to more than 300 freeze-thaw cycles, high strength was confirmed. For this reason, it is exposed that the influence of the freeze-thaw action under the actual environment is small. In the early material ages, the scaling amount was higher as W/B was larger and air was smaller, similar to the general tendency. On the other hand, with the material age, the resistance was greatly improved, and at 365 days curing, it became 0.25 g/cm2 or less in all the mix proportions, and no correlation by air was observed. Therefore, it is expected that the influence of the expansion pressure is small and influence of the osmotic pressure due to chloride ions or the like is large. In conclusion, LPC-FA concrete is considered to have sufficient practicality.

Index Terms—frost damage, low heat portland cement, fly ash, air voids structure, compressive strength

Cite: S. Kawamorita and K. Niwase, "Basic Research on Frost Resistance of LPC-FA Concrete Placed in Chloride Environment," International Journal of Structural and Civil Engineering Research, Vol. 9, No. 3, pp. 264-268, August 2020. doi: 10.18178/ijscer.9.3.264-268