Compressive behavior and freeze-thaw durability of concrete after exposure to high temperature

Abstract

In order to research the compressive strength and freeze-thaw durability of recycled aggregate concrete (RAC) under the combined actions of high temperature and freeze thawing recycle, a total of 240 cube specimens with different mix proportions were produced. In this article, two kinds of freeze-thaw tests were carried out: the specimens immersed in water (FTW) and the specimens immersed in salt solution (FTS). The influences of four factors on the freeze-thaw durability of the concrete were analyzed, such as temperatures, recycled aggregate replacement ratios, water-binder ratios and fly ash dosages. The results indicate that the four factors all have significant effects on the compressive strength of the concrete specimens. The recycled concrete contained 30% fly ash has better resistance against to the high temperature and freeze thawing deterioration. In addition, salt-frost specimen has more severe denudation than water-frost specimen, and the compressive strength loss of salt-frost specimen is much larger than that of water-frost specimen. The results can provide the theoretical basis on the durability design of RAC subjected to harsh environmental conditions.

Keywords:

• Recycled aggregate concrete
• freeze-thaw durability
• high temperature
• compressive strength
• water-binder ratio
• fly ash

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research is supported by the National Natural Science Foundation of China (51108371), Opening Funds of State Key Laboratory of Building Safety and Built Environment (BSBE2016-02), Key Laboratory of the Education Department of Shaanxi Province (16JS050).