A study on the change in frost resistance and pore structure of concrete containing blast furnace slag under the carbonation conditions

In this study, the change in frost resistance and pore structure of concrete containing blast furnace slag with various replacement ratio due to carbonation were investigated. As a result, there is a close relationship between the carbonation speed and 28-day compressive strength in blast furnace slag concrete. The frost resistance, carbonation resistance and scaling resistance of blast furnace slag cement concrete decrease as blast furnace slag replacement ratio increases. Furthermore, due to carbonation, the frost durability of ordinary Portland cement concrete and the concrete with a low replacement ratio of blast furnace slag tends to decrease. However, the concrete with a high replacement ratio of blast furnace slag tends to increase. Under the carbonation conditions, the pore volume decreases due to carbonation of calcium hydroxide, and the pore structure will be coarsened due to carbonation of C-S-H. In addition, it is expected that permeability of concrete is raised and scaling is inhibited due to carbonation, and the surface area with a certain thickness in the carbonated concrete will be scaled due to freeze-thaw.

Automated summary

In this study, the influence of carbonation on the frost resistance and pore structure of blast furnace slag concrete was investigated. The results showed that the carbonation speed is closely related to the 28-day compressive strength of the concrete. The frost resistance, carbonation resistance and scaling resistance of blast furnace slag concrete decrease as the replacement ratio of blast furnace slag increases. Moreover, carbonation affects the pore volume and structure of the concrete.