**4. Conclusions**

In this research, the durability of concrete with added BA was evaluated by immersing specimens in a solution containing 10% sodium sulfate. Then, capillary rise, crystallization rate, and solution absorption tests were performed to investigate the intrusion of concrete by sodium sulfate solution. Moreover, the crucial type of porosity was found with the help of porosity measurements. The following conclusions can be drawn:


Furthermore, due to BA adjusting the strength and durability of the concrete, the optimum range of BA in concrete is from 10% to 15%. In this range, BA can not only improve the durability of concrete but also ensure the strength of concrete to meet design requirements.

The deficiency of this study is that no suitable treatment measures were found to enhance the hydration activity of BA. The objective of future research studies in this area is to improve the activity of BA by wet and high-temperature treatment. On this basis, the effect of BA on the strength and durability of concrete can be studied.

**Author Contributions:** Y.C. proposed the research method for analyzing the intrusion of sodium sulfate solution to reveal the durability of concrete. The experiments were performed and the manuscript was written by J.D., G.Z., C.C. and D.W. Y.D. proposed revision suggestions for this manuscript.

**Funding:** This research was funded by the Construction System Science and Technology Project in Jiangsu, China (Grant No. 2018ZD045), and the Training Program on Entrepreneurship and Innovation for University Students (Grant No. 2019JGYJ003 and 201911049023Y).

**Conflicts of Interest:** The authors declare that there are no conflicts of interest regarding the publication of this paper.
