**5. Conclusions and Suggestions for Future Works**

Regardless of the differences in waste material used in geopolymerization, the selection of raw materials depends on the desired application. Waste material-based geopolymer rich in silicon, aluminium, and calcium are easy and highly accessible. This facilitates

their disposal waste management rather than building a landfill full of them. This is the main reason behind the low cost of manufacturing geopolymeric composites-based waste material in civil and military application. The utilization of waste materials through geopolymerization should be carried out in future works to mitigate the disposal and environmental issues. Numerous studies have been conducted involving the use of wastebased geopolymers with promising properties for heavy-duty applications such as military, civil-engineering, and road applications.

Based on the identified gaps in this work, future recommendations on waste-material based geopolymer in heavy duty application are listed below:


**Author Contributions:** Conceptualization, original draft preparation, writing, review and editing, I.H.A. and M.K.; validation, project administration, supervision, visualization and resources, M.M.A.B.A.; methodology and validation, M.A. and R.A.R. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research work was funded by Institutional Fund Projects under Grant No. (IFPIP: 434-829-1442). Therefore, the authors gratefully acknowledge technical and financial support from the Ministry of Education and King Abdulaziz University, DSR Jeddah, Saudi Arabia.

**Institutional Review Board Statement:** Not Applicable.

**Informed Consent Statement:** Not Applicable.

**Data Availability Statement:** Not Applicable.

**Acknowledgments:** The authors gratefully acknowledge the Centre of Excellence Geopolymer and Green Technology (CEGeoGTech) and the Faculty of Chemical Engineering Technology, UniMAP for their expertise and support and the Dean of Scientific Research in King Abdulaziz University, Jeddah, Saudi Arabia.

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

#### **References**

