No abstract

In order to explore the frost resistance durability of basalt fiber reinforced concrete (BFRC), the freeze-thaw cycle tests of BFRC with different fiber contents were carried out from the microscopic point of view, and the macro-morphological deterioration characteristics and micro-morphological characteristics of BFRC with different freeze-thaw cycles were analyzed. By testing the hole structure parameters of BFRC with different freeze-thaw cycles, the effects of gas content, average bubble chord length, specific surface area, and bubble spacing coefficient on the frost resistance of BFRC were studied. The results show that: With the increase of fiber content, the damage degree of concrete specimens weakens, and the proportion of harmful pores in the pore size distribution increases significantly; It decreases with the increase of bubble spacing coefficient; The addition of basalt fiber can effectively inhibit the development of cracks and reduce the probability of large pores in the process of concrete freeze-thaw damage, thereby improving the frost resistance of concrete. Therefore, for the northern region, the research on the frost resistance of BFRC is very necessary and of great significance.

In order to explore the frost resistance of high-performance activated cement-based composites(HACC), The freeze-thaw cycle test of HACC with different water-binder ratio and basalt fiber content was carried out, the mass loss rate, relative dynamic elastic modulus and related pore structure parameters of different freeze-thaw cycles were measured, and the influence of different factors on the frost resistance of HACC was studied, and the variation law of pore structure parameters with freeze-thaw cycles was explored. The results show that the mass loss rate of high performance cement-based composites has a small range, the maximum is less than 1% during failure, and the relative dynamic modulus changes significantly, which is the main indicator to evaluate the freeze-thaw failure of HACC; The frost resistance of HACC decreased gradually with the increase of the water-binder ratio, and showed a change rule of first increasing and then decreasing with the increase of basalt fiber content; HACC have good frost resistance when the air content is 3% ~ 4%. The bubble chord length is directly related to the freeze-thaw deterioration characteristics of HACC, and the bubble chord length reflects the frost resistance of HACC to some extent.