Study on failure mechanism of concrete subjected to freeze-thaw condition in airport deicers

The rapid freeze–thaw test about ordinary Portland cement concrete (PCC) was performed in the deicers of water, 3.5% ethylene glycol, 3.5% NaCl and 3.5% calcium magnesium acetate (CMA). The ice pressure ( I p ) of deicer was tested, and the concept of the ice pressure impulse ( IPI ) was proposed. A crack density model was employed to describe the freeze–thaw damage process of concrete. Results indicated that the freeze–thaw damage of PCC in CMA deicer was the mildest. The I p value of water was the highest but its IPI value was the lowest. The freeze–thaw microcracks inside concrete was induced by the I p of deicer restrained in concrete pores. The freeze–thaw crack density decreased with the relative depth of specimen. The value of superficial critical crack density was 0.85 ∼ 0.88, when the exterior mortar of concrete began spalling. The value of central critical crack density was 0.32 ∼ 0.34, when the interior freeze–thaw failure of concrete occurred.