**4. Conclusions**

**4. Conclusion**  The long-term performance of concrete comprising WPFT fibers and POFA was investigated against sulfate and acid attacks after 365 days. Concrete specimens were exposed to 10% MgSO4 and 5% H2SO4 solutions. The performance of the concrete mixtures The long-term performance of concrete comprising WPFT fibers and POFA was investigated against sulfate and acid attacks after 365 days. Concrete specimens were exposed to 10% MgSO<sup>4</sup> and 5% H2SO<sup>4</sup> solutions. The performance of the concrete mixtures was assessed with the help of visual inspection, mass change, residual strength, and microstructural analysis. In the light of attained outcomes, the following conclusions can be drawn:


positive. The rate of mass change in mixtures comprising WPFT fiber and POFA, on the other hand, was lower than that in the OPC combinations. Adding WPFT fibers to concrete exposed to chemical attacks was a good technique for controlling mass changes. The mass loss of POFA concrete specimens reinforced with 1% fibers after 12 months of exposure in the H2SO<sup>4</sup> solution was recorded as 3.5%, which is comparatively lower than that of the 15.5% recorded for the plain concrete without fibers.


**Author Contributions:** All authors contributed to the paper evenly. Conceptualization, H.M. and R.A.; methodology, H.M. and R.A.; software H.M., S.P.N. and R.A.; validation, H.M. and R.A.; formal analysis, H.M. and R.A.; investigation, H.M. and R.A.; resources, H.M. and R.A.; data curation, H.M., S.P.N. and R.A.; writing—original draft preparation, H.M., M.M.T. and R.A.; writing—review and editing, H.M. and R.A.; visualization, H.M., S.P.N. and R.A.; supervision, M.M.T.; project administration, R.A. and S.P.N.; funding acquisition, H.M. and R.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by University of Technology Malaysia under Postdoctoral fellowship grants.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the size of the research.

**Acknowledgments:** The authors would like to acknowledge the financial and technical supports received from Universiti Teknologi Malaysia and Prince Sattam Bin Abdulaziz University (Saudi Arabia).

**Conflicts of Interest:** The authors declare no conflict of interest.

### **References**

