1. Introduction

Mine tailings collect in tailings ponds and mine waste dumps, and proper disposal of these wastes is becoming more important [1, 2]. This is owing to the rising output volumes of the metallurgical and mining sectors, as well as the absence of an acceptable way of disposing of the waste generated by these businesses, on the one hand. On the other side, it may be explained by the rising stringency of environmental legislation in the majority of affluent nations worldwide. Lead and mercury, radioactive elements, and other mining tails-related pollutants are actively released into the environment as a consequence of the building of tails, biota, contaminating soils, air, and water, and causing cancer in people. Pollutants from food production and feed waste wreak havoc on valuable farms and natural habitats. The operation of tailing dams increases the chance of man-made disasters happening [3, 4]. ‎

Furthermore, mine tailings should be seen as a mineral supply that has been removed from the earth's subsurface, transported, and misused from the perspective of rational natural resource management. The tailings may include trace quantities of target material as well as previously unclaimed components that can be reclaimed using more efficient mining processes‎[5-10], which is one reason for this viewpoint. The chemical composition of mine tailings, on the other hand, is primarily composed of silicon, aluminum, and calcium oxides, with a percentage ranging from 60 to 90% [1-4, 11, 12]. As a consequence, tailings have the potential to act as an alternate source for addressing a variety of building and industrial needs [12-14].

A promising trend in the use of mine tailings seems to be the use of mine tailings as geopolymers and precursors of alkali-activated materials or aggregates [15-17]. Geopolymers are materials that are largely made of amorphous sodium aluminum silicate hydrate.[18]. They are mostly solids that result from the interaction of an aluminosilicate powder and an alkali solution.[19]. According to van Deventer, et al [18], the geopolymer network is composed of AlO₄ and SiO₄ tetrahedra connected by oxygen atoms [19]; Positively charged ions (e.g., Ca₂⁺, Na⁺, K⁺, and Li⁺) present in the cavity framework balance the negative charge. It is possible that using mine tailings as a geopolymer approach will not only slow down the accumulation of mine tailings and reduce the level of ecological contamination, but it will also combine the benefits of geopolymer technology associated with a reduction in carbon dioxide release into the environment, the possibility of utilizing other forms of aluminosilicate waste, and the versatility of geopolymer characteristics [20-24]. There has recently been a significant gain in knowledge across a varied set of professionals in the management of tails in common approaches. Over a dozen studies have been published documenting the efforts done to improve our knowledge of the geopolymerization processes of tails in order to manage the characteristics of geopolymers for applications such as pollution removal [25-27], sustainable building [28-32], and another particular usage [13-17].

The mine tailings are inhomogeneous and have a complex mineral, aggregate, and chemical composition [11, 33-39]. Furthermore, although having relatively low quantities of valuable components, mine tailings contain hazardous and toxic compounds connected with waste products or mining activities [40-44]. All of these aspects make it more difficult to directly manage mine tailings in order to create geopolymers that fulfill environmental safety regulations in terms of impurity content while also obtaining the needed complicated functional qualities for the manufactured product. [45, 46].

As a consequence, addressing the challenges connected with the usage of mine tailings-geopolymer composites is particularly beneficial, both in terms of reducing the negative environmental effect and the promise of expanding the resource base of manufactured mineral raw materials. It is very advantageous to tackle the challenges associated with the usage of mine tailings-geopolymer composites. This review starts with a discussion of some of the physicochemical and environmental challenges surrounding the use of mine tailings-geopolymer composites. This study discusses mine tailings-geopolymer composites in depth, which is both a generalization and a detailed research of the relationship between their structural, mechanical, and thermal capacities, as well as their durability and other significant elements. Aside from the helpful properties of the development of the characteristics of mine tailings-geopolymer composites, we thoroughly address the well-known examples of their exploitation in prospective applications.

2. Durability properties

Only a few researchers have examined the long-term durability of mine tailings-geopolymer composites. With the help of Caballero, et al [47], the gold mine tailings-geopolymer was exposed to sulfate and acid solutions as well as high temperatures. According to its findings, as compared to a reference cementitious composite, the rate of loss in compressive strength with immersion time in sulfuric and nitric acid solutions is pretty equal in gold mine tailings-geopolymer composites. Similar results have been seen in magnesium and sodium sulfate solutions, as well as when the solutions are exposed to high temperatures. Ahmari and Zhang [48] discovered that copper mine tailings-geopolymer composites submerged for 120 days in aqueous solutions with pH values ranging between 4 and 7 had a substantial drop (by 58–79% compared to reference specimens) in their plain compressive strength. The high initial Si/Al proportion and partial geopolymerization of the mine tailings, according to the scientists, were responsible for this result. Water absorption and weight loss, on the other hand, were quite minor and had lower values in comparison to the OPC-based binding agent. Another study by Ahmari and Zhang [49] showed that introducing cement kiln dust can improve durability and unconfined compressive strength. The beneficial impact of cement kiln dust was connected to improved aluminosilicate dissolving, production of calcium carbonate, and calcium incorporation into the geopolymer system. Falayi [50] demonstrated that activating with potassium aluminate results in a better resistance of geopolymers to alternate wetting and drying than potassium silicate. In every case, the UCS values dropped more than threefold after 10 wet and dry cycles [51-56]. This makes it difficult to use these composites in places where there is a lot of wet and dry time, and it also makes it important to look into ways to mitigate this.

The utilization of tailings to substitute natural aggregates (gravel or sand) in geopolymer concretes, either partially or completely, might lead to an upsurge in the water absorption and porosity of the latter [45, 46, 57-60]. In turn, this can make these substances more vulnerable to chemical assault, which can have a detrimental impact on their overall durability. Further investigation in this field is needed because of a lack of understanding about these and other characteristics of the durability of mine tailings-geopolymer composites, which suggests a need for future research in this area.

3. Microstructure properties

The microstructure of geopolymerization products; the content, structure, and proportion of the produced amorphous and crystalline phases; as well as the existence, distribution, and size of pores, are all useful factors in determining the attributes of mine tailings-geopolymer composites.

Falah, et al [61] found that rising the sodium silicate content of a copper mine tailings-geopolymer composite by up to 30% densifies the microstructure of the material. It was also discovered that, at such a concentration of sodium silicate, almost the whole geopolymer is changed into fused rectangular prisms, which indicates a full transition to high alkaline conditions. Manjarrez, et al [62] have discovered that when copper slag is put into its geopolymer, the density of the geopolymer rises as assessed by SEM image analysis. Its results show that copper slag increased the breadth of the amorphous peak in the XRD of copper mine tailings-geopolymer composites, whereas the crystalline peak in the copper mine tailings remained the same after geopolymerization, which is compatible with the SEM findings [63-67].

The XRD examination findings of its 28-day-cured geopolymer also reveal a lowering in the ferocity of crystalline peaks, suggesting that the dissolution of the Al and Si components in the geopolymerization process has progressed farther than previously thought. SEM pictures of copper mine tailings-geopolymer composites obtained in the work by Ren, et al [68] show that raised aluminum sludge levels lead to the development of more geopolymer gels. In addition, they verified that there were no unreacted particles at an aluminum sludge concentration of 21% in their experiment. According to Ahmari and Zhang [49] investigation, as shown in Fig. 1, the enhanced microstructure of copper mine tailings-geopolymer composites is due to the incorporation of cement kiln dust, which leads to the creation of more geopolymer gels, as seen by an increased Si/Al ratio [69-74].

Due to the incorporation of iron mine tailings into fly ash-geopolymer composites, Duan et al. demonstrated that the geopolymer became denser by producing more C–S–H [75, 76]. They also analyzed the microstructure of their geopolymer after it had been subjected to elevated temperatures and discovered that it had suffered no considerable damage to its microstructure after seven heating cycles at 200 ºC. Increased numbers of pores and fractures were found after 800 ºC exposure in fly ash-geopolymer composites that did not include iron mine tailings, but this was not the case in fly ash-geopolymer composites that included iron mine tailings after the same exposure.

4. Conclusions

The key annotations for this paper review are as follows:

1. According to the investigation, geopolymers seem to be attractive options for recovering mine waste and generating sustainable building and construction materials, mine paste backfills, and stabilizing materials for hazardous element This strategy not only provides for a reduction in the carbon footprint associated with typical cementitious materials but also avoids the substantial ecological contamination produced by mine waste buildup.
2. Mine tailings are often composed of a highly crystalline matrix, which results in minimal interaction throughout geopolymerization and, consequently, a product with low mechanical Incorporating extra elements with increased interaction into mine tailings-geopolymer composites may efficiently tune and enhance the characteristics of the geopolymers. Furthermore, since the majority of the additives utilized for this function are industrial by-products, their usage has the additional benefit of reducing the amount of waste produced.
3. When compared to low-Ca-comprising additions, high-Ca-comprising elements have a more favorable impact on the geopolymer's overall strength and This is induced by the production of extra CSH gels, which strengthen the matrix as a result of its co-existence with NASH, which improves the matrix density.

References

[1] S. Qaidi, "Behaviour of Concrete Made of Recycled Waste PET and Confined with CFRP Fabrics," M.Sc., University of Duhok, Duhok, 2021.

[2] J. Ahmad et al., "A Comprehensive Review on the Ground Granulated Blast Furnace Slag (GGBS) in Concrete Production," Sustainability, vol. 14, no. 14, p. 8783, 2022 [Online]. Available: https://www.mdpi.com/2071-1050/14/14/8783.

[3] H. U. Ahmed, A. S. Mohammed, S. M. Qaidi, R. H. Faraj, N. Hamah Sor, and A. A. Mohammed, "Compressive strength of geopolymer concrete composites: a systematic comprehensive review, analysis and modeling," European Journal of Environmental and Civil Engineering, pp. 1-46, 2022.

[4] H. U. Ahmed, A. S. Mohammed, R. H. Faraj, S. M. Qaidi, and A. A. Mohammed, "Compressive strength of geopolymer concrete modified with nano-silica: Experimental and modeling investigations," Case Studies in Construction Materials, vol. 16, p. e01036, 2022.

[5] M. Rico, G. Benito, A. Salgueiro, A. Díez-Herrero, and H. Pereira, "Reported tailings dam failures: a review of the European incidents in the worldwide context," Journal of hazardous materials, vol. 152, no. 2, pp. 846-852, 2008.

[6] C. Zhang, X. Wang, Z. Hu, Q. Wu, H. Zhu, and J. Lu, "Long-term performance of silane coupling agent/metakaolin based geopolymer," Journal of Building Engineering, vol. 36, p. 102091, 2021/04/01/ 2021, doi: https://doi.org/10.1016/j.jobe.2020.102091.

[7] C. Rodrigue Kaze et al., "Synergetic effect of rice husk ash and quartz sand on microstructural and physical properties of laterite clay based geopolymer," Journal of Building Engineering, vol. 43, p. 103229, 2021/11/01/ 2021, doi: https://doi.org/10.1016/j.jobe.2021.103229.

[8] K. M. Klima, K. Schollbach, H. J. H. Brouwers, and Q. Yu, "Enhancing the thermal performance of Class F fly ash-based geopolymer by sodalite," Construction and Building Materials, vol. 314, p. 125574, 2022/01/03/ 2022, doi: https://doi.org/10.1016/j.conbuildmat.2021.125574.

[9] K. V. S. Gopala Krishna Sastry, P. Sahitya, and A. Ravitheja, "Influence of nano TiO2 on strength and durability properties of geopolymer concrete," Materials Today: Proceedings, vol. 45, pp. 1017-1025, 2021/01/01/ 2021, doi: https://doi.org/10.1016/j.matpr.2020.03.139.

[10] M. Catauro, F. Barrino, S. Pacifico, S. Piccolella, I. Lancellotti, and C. Leonelli, "Synthesis of WEEE-based geopolymers and their cytotoxicity," Materials Today: Proceedings, vol. 34, pp. 121-124, 2021/01/01/ 2021, doi: https://doi.org/10.1016/j.matpr.2020.01.408.

[11] G. Lazorenko, A. Kasprzhitskii, F. Shaikh, R. Krishna, and J. Mishra, "Utilization potential of mine tailings in geopolymers: Part 1. Physicochemical and environmental aspects," Process Safety and Environmental Protection, 2021.

[12] H. U. Ahmed et al., "Compressive Strength of Sustainable Geopolymer Concrete Composites: A State-of-the-Art Review," Sustainability, vol. 13, no. 24, p. 13502, 2021 [Online]. Available: https://www.mdpi.com/2071-1050/13/24/13502.

[13] F. A. Jawad Ahmad, Rebeca Martinez‑Garcia, Jesús de‑Prado‑Gil, Shaker M. A. Qaidi, Ameni Brahmia, "Effects of waste glass and waste marble on mechanical and durability performance of concrete," Scientific Reports, vol. 11, no. 1, p. 21525, 2021.

[14] F. Aslam et al., "Evaluating the influence of fly ash and waste glass on the characteristics of coconut fibers reinforced concrete," Structural Concrete, vol. n/a, no. n/a, doi: https://doi.org/10.1002/suco.202200183.

[15] M. M. Al-Tayeb, Y. I. A. Aisheh, S. M. A. Qaidi, and B. A. Tayeh, "Experimental and simulation study on the impact resistance of concrete to replace high amounts of fine aggregate with plastic waste," Case Studies in Construction Materials, p. e01324, 2022/07/19/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e01324.

[16] H. Unis Ahmed et al., "Geopolymer concrete as a cleaner construction material: An overview on materials and structural performances," Cleaner Materials, vol. 5, p. 100111, 2022/09/01/ 2022, doi: https://doi.org/10.1016/j.clema.2022.100111.

[17] A. Mansi, N. H. Sor, N. Hilal, and S. M. Qaidi, "The impact of nano clay on normal and high-performance concrete characteristics: a review," in IOP Conference Series: Earth and Environmental Science, 2022, vol. 961, no. 1: IOP Publishing, p. 012085.

[18] J. S. van Deventer, J. L. Provis, P. Duxson, and D. G. Brice, "Chemical research and climate change as drivers in the commercial adoption of alkali activated materials," Waste and Biomass Valorization, vol. 1, no. 1, pp. 145-155, 2010.

[19] J. L. Provis and J. S. J. Van Deventer, Geopolymers: structures, processing, properties and industrial applications. Elsevier, 2009.

[20] G. Lazorenko et al., "Effect of pre-treatment of flax tows on mechanical properties and microstructure of natural fiber reinforced geopolymer composites," Environmental Technology & Innovation, vol. 20, p. 101105, 2020.

[21] G. Lazorenko, A. Kasprzhitskii, A. Kruglikov, V. Mischinenko, and V. Yavna, "Sustainable geopolymer composites reinforced with flax tows," Ceramics International, vol. 46, no. 8, pp. 12870-12875, 2020.

[22] A. Hassan, M. Arif, and M. Shariq, "Use of geopolymer concrete for a cleaner and sustainable environment–A review of mechanical properties and microstructure," Journal of cleaner production, vol. 223, pp. 704-728, 2019.

[23] M. Chau-Khun, A. A. Zawawi, and O. Wahid, "Structural and material performance of geopolymer concrete 2018," ed: ELSEVIER, 2018.

[24] S. T, K. R. P.R, S. M, S. A, and J. R, "A state-of-the-art on development of geopolymer concrete and its field applications," Case Studies in Construction Materials, vol. 16, p. e00812, 2022/06/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2021.e00812.

[25] F. Demir and E. Moroydor Derun, "Usage of gold mine tailings based geopolymer on Cu 2+ adsorption from water," Main Group Chemistry, vol. 18, no. 4, pp. 467-476, 2019.

[26] F. Demir and E. M. Derun, "Modelling and optimization of gold mine tailings based geopolymer by using response surface method and its application in Pb2+ removal," Journal of Cleaner Production, vol. 237, p. 117766, 2019.

[27] A. A. Siyal et al., "A review on geopolymers as emerging materials for the adsorption of heavy metals and dyes," Journal of Environmental Management, vol. 224, pp. 327-339, 2018/10/15/ 2018, doi: https://doi.org/10.1016/j.jenvman.2018.07.046.

[28] S. Moukannaa, A. Nazari, A. Bagheri, M. Loutou, J. Sanjayan, and R. Hakkou, "Alkaline fused phosphate mine tailings for geopolymer mortar synthesis: Thermal stability, mechanical and microstructural properties," Journal of Non-Crystalline Solids, vol. 511, pp. 76-85, 2019.

[29] N. Zhang, A. Hedayat, H. G. Bolaños Sosa, N. Tupa, I. Yanqui Morales, and R. S. Canahua Loza, "Crack evolution in the Brazilian disks of the mine tailings-based geopolymers measured from digital image correlations: An experimental investigation considering the effects of class F fly ash additions," Ceramics International, vol. 47, no. 22, pp. 32382-32396, 2021/11/15/ 2021, doi: https://doi.org/10.1016/j.ceramint.2021.08.138.

[30] N. Zhang et al., "On the incorporation of class F fly-ash to enhance the geopolymerization effects and splitting tensile strength of the gold mine tailings-based geopolymer," Construction and Building Materials, vol. 308, p. 125112, 2021/11/15/ 2021, doi: https://doi.org/10.1016/j.conbuildmat.2021.125112.

[31] N. Zhang, A. Hedayat, H. G. Bolaños Sosa, J. J. González Cárdenas, G. E. Salas Álvarez, and V. B. Ascuña Rivera, "Specimen size effects on the mechanical behaviors and failure patterns of the mine tailings-based geopolymer under uniaxial compression," Construction and Building Materials, vol. 281, p. 122525, 2021/04/26/ 2021, doi: https://doi.org/10.1016/j.conbuildmat.2021.122525.

[32] A. R. de Azevedo et al., "Circular economy and durability in geopolymers ceramics pieces obtained from glass polishing waste," International Journal of Applied Ceramic Technology, 2021.

[33] S. M. A. Qaidi, "Ultra-high-performance fiber-reinforced concrete: Mixture design," University of Duhok, Duhok, 2022.

[34] S. M. A. Qaidi, "Ultra-high-performance fiber-reinforced concrete: Principles and raw materials," University of Duhok, Duhok, 2022.

[35] M. H. Akeed et al., "Ultra-high-performance fiber-reinforced concrete. Part I: Developments, principles, raw materials," Case Studies in Construction Materials, vol. 17, p. e01290, 2022/12/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e01290.

[36] M. H. Akeed et al., "Ultra-high-performance fiber-reinforced concrete. Part II: Hydration and microstructure," Case Studies in Construction Materials, vol. 17, p. e01289, 2022/12/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e01289.

[37] M. H. Akeed et al., "Ultra-high-performance fiber-reinforced concrete. Part III: Fresh and hardened properties," Case Studies in Construction Materials, vol. 17, p. e01265, 2022/12/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e01265.

[38] M. H. Akeed et al., "Ultra-high-performance fiber-reinforced concrete. Part IV: Durability properties, cost assessment, applications, and challenges," Case Studies in Construction Materials, vol. 17, p. e01271, 2022/12/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e01271.

[39] S. M. A. Qaidi et al., "Ultra-high-performance geopolymer concrete: A review," Construction and Building Materials, vol. 346, p. 128495, 2022/09/05/ 2022, doi: https://doi.org/10.1016/j.conbuildmat.2022.128495.

[40] C. Anning, J. Wang, P. Chen, I. Batmunkh, and X. Lyu, "Determination and detoxification of cyanide in gold mine tailings: A review," Waste Management & Research, vol. 37, no. 11, pp. 1117-1126, 2019.

[41] I. Park et al., "A review of recent strategies for acid mine drainage prevention and mine tailings recycling," Chemosphere, vol. 219, pp. 588-606, 2019.

[42] E. M. Opiso, C. B. Tabelin, C. V. Maestre, J. P. J. Aseniero, I. Park, and M. Villacorte-Tabelin, "Synthesis and characterization of coal fly ash and palm oil fuel ash modified artisanal and small-scale gold mine (ASGM) tailings based geopolymer using sugar mill lime sludge as Ca-based activator," Heliyon, vol. 7, no. 4, p. e06654, 2021/04/01/ 2021, doi: https://doi.org/10.1016/j.heliyon.2021.e06654.

[43] G. Lazorenko, A. Kasprzhitskii, F. Shaikh, R. S. Krishna, and J. Mishra, "Utilization potential of mine tailings in geopolymers: Physicochemical and environmental aspects," Process Safety and Environmental Protection, vol. 147, pp. 559-577, 2021/03/01/ 2021, doi: https://doi.org/10.1016/j.psep.2020.12.028.

[44] E. Arioz, O. Arioz, and O. M. Kockar, "Leaching of F-type fly Ash Based Geopolymers," Procedia Engineering, vol. 42, pp. 1114-1120, 2012/01/01/ 2012, doi: https://doi.org/10.1016/j.proeng.2012.07.503.

[45] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 1: Manufacture approaches," University of Duhok, Duhok, 41, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:maZDTaKrznsC

[46] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 2: Applications," University of Duhok, Duhok, 42, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:M3NEmzRMIkIC

[47] E. Caballero, W. Sánchez, and C. A. Ríos, "Synthesis of geopolymers from alkaline activation of gold mining wastes," Ingeniería y competitividad, vol. 16, no. 1, pp. 317-330, 2014.

[48] S. Ahmari and L. Zhang, "Durability and leaching behavior of mine tailings-based geopolymer bricks," Construction and building materials, vol. 44, pp. 743-750, 2013.

[49] S. Ahmari and L. Zhang, "Utilization of cement kiln dust (CKD) to enhance mine tailings-based geopolymer bricks," Construction and Building Materials, vol. 40, pp. 1002-1011, 2013.

[50] T. Falayi, "Effect of potassium silicate and aluminate on the stabilisation of gold mine tailings," in Proceedings of the Institution of Civil Engineers-Waste and Resource Management, 2019, vol. 172, no. 2: Thomas Telford Ltd, pp. 56-63.

[51] Y. I. A. Aisheh, D. S. Atrushi, M. H. Akeed, S. Qaidi, and B. A. Tayeh, "Influence of polypropylene and steel fibers on the mechanical properties of ultra-high-performance fiber-reinforced geopolymer concrete," Case Studies in Construction Materials, vol. 17, p. e01234, 2022.

[52] Y. I. A. Aisheh, D. S. Atrushi, M. H. Akeed, S. Qaidi, and B. A. Tayeh, "Influence of steel fibers and microsilica on the mechanical properties of ultra-high-performance geopolymer concrete (UHP-GPC)," Case Studies in Construction Materials, vol. 17, p. e01245, 2022/12/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e01245.

[53] I. Almeshal, M. M. Al-Tayeb, S. M. A. Qaidi, B. H. Abu Bakar, and B. A. Tayeh, "Mechanical properties of eco-friendly cements-based glass powder in aggressive medium," Materials Today: Proceedings, vol. 58, pp. 1582-1587, 2022/01/01/ 2022, doi: https://doi.org/10.1016/j.matpr.2022.03.613.

[54] X. He et al., "Mine tailings-based geopolymers: A comprehensive review," Ceramics International, vol. 48, no. 17, pp. 24192-24212, 2022/09/01/ 2022, doi: https://doi.org/10.1016/j.ceramint.2022.05.345.

[55] R. H. Faraj, H. U. Ahmed, S. Rafiq, N. H. Sor, D. F. Ibrahim, and S. M. A. Qaidi, "Performance of Self-Compacting Mortars Modified with Nanoparticles: A Systematic Review and Modeling," Cleaner Materials, no. 2772-3976, p. 100086, 2022.

[56] S. M. A. Qaidi, "PET-Concrete," University of Duhok, Duhok, 2021.

[57] P. H. Ribeiro Borges, F. C. Resende Ramos, T. Rodrigues Caetano, T. Hallak Panzerra, and H. Santos, "Reuse of iron ore tailings in the production of geopolymer mortars," Rem: Revista Escola de Minas, vol. 72, no. 4, 2019.

[58] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 3: Environmental parameters," University of Duhok, Duhok, 43, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:JV2RwH3_ST0C

[59] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 4: Mix design methods ‎," University of Duhok, Duhok, 44, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:blknAaTinKkC

[60] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 5: Fresh properties," University of Duhok, Duhok, 45, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:hMod-77fHWUC

[61] M. Falah, R. Obenaus-Emler, P. Kinnunen, and M. Illikainen, "Effects of activator properties and curing conditions on alkali-activation of low-alumina mine tailings," Waste and Biomass Valorization, pp. 1-13, 2019.

[62] L. Manjarrez, A. Nikvar-Hassani, R. Shadnia, and L. Zhang, "Experimental study of geopolymer binder synthesized with copper mine tailings and low-calcium copper slag," Journal of Materials in Civil Engineering, vol. 31, no. 8, p. 04019156, 2019.

[63] S. M. A. Qaidi, "PET-concrete confinement with CFRP," University of Duhok, Duhok, 2021.

[64] S. M. Qaidi, B. A. Tayeh, A. M. Zeyad, A. R. de Azevedo, H. U. Ahmed, and W. Emad, "Recycling of mine tailings for the geopolymers production: A systematic review," Case Studies in Construction Materials, p. e00933, 2022.

[65] S. M. A. Qaidi et al., "Rubberized geopolymer composites: A comprehensive review," Ceramics International, vol. 48, no. 17, pp. 24234-24259, 2022/09/01/ 2022, doi: https://doi.org/10.1016/j.ceramint.2022.06.123.

[66] A. M. Jawad Ahmad, Ahmed Babeker Elhag, Ahmed Farouk Deifalla, Mahfooz Soomro, Haytham F. Isleem, Shaker Qaidi, "A Step towards Sustainable Concrete with Substitution of Plastic Waste in Concrete: Overview on Mechanical, Durability and Microstructure Analysis," Crystals, vol. 12, no. 7, p. 944, 2022.

[67] A. M. Maglad et al., "A Study on the Properties of Geopolymer Concrete Modified with Nano Graphene Oxide," Buildings, vol. 12, no. 8, p. 1066, 2022 [Online]. Available: https://www.mdpi.com/2075-5309/12/8/1066.

[68] X. Ren, L. Zhang, D. Ramey, B. Waterman, and S. Ormsby, "Utilization of aluminum sludge (AS) to enhance mine tailings-based geopolymer," Journal of materials science, vol. 50, no. 3, pp. 1370-1381, 2015.

[69] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 6: Mechanical properties," University of Duhok, Duhok, 46, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:NMxIlDl6LWMC

[70] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 7: Mechanical performance correlation," University of Duhok, Duhok, 47, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:YFjsv_pBGBYC

[71] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 8: Dynamic behavior," University of Duhok, Duhok, 48, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:BqipwSGYUEgC

[72] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 9: Strain hardening," University of Duhok, Duhok, 49, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:GnPB-g6toBAC

[73] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 10: Durability properties," University of Duhok, Duhok, 50, 2022.

[74] S. Qaidi, "Ultra-high-performance geopolymer concrete. Part 11: Microstructural properties," University of Duhok, Duhok, 51, 2022 [Online]. Available: https://scholar.google.com/citations?view_op=view_citation&hl=en&user=V5wA2xMAAAAJ&cstart=20&pagesize=80&sortby=title&citation_for_view=V5wA2xMAAAAJ:M3NEmzRMIkIC

[75] P. Duan, C. Yan, W. Zhou, and D. Ren, "Development of fly ash and iron ore tailing based porous geopolymer for removal of Cu (II) from wastewater," Ceramics International, vol. 42, no. 12, pp. 13507-13518, 2016.

[76] P. Duan, C. Yan, W. Zhou, and D. Ren, "Fresh properties, compressive strength and microstructure of fly ash geopolymer paste blended with iron ore tailing under thermal cycle," Construction and Building Materials, vol. 118, pp. 76-88, 2016.

[77] G. Liang, H. Zhu, Z. Zhang, and Q. Wu, "Effect of rice husk ash addition on the compressive strength and thermal stability of metakaolin based geopolymer," Construction and Building Materials, vol. 222, pp. 872-881, 2019.

[78] H. Y. Zhang, G. H. Qiu, V. Kodur, and Z. S. Yuan, "Spalling behavior of metakaolin-fly ash based geopolymer concrete under elevated temperature exposure," Cement and Concrete Composites, vol. 106, p. 103483, 2020.

[79] S. M. A. Qaidi, B. A. Tayeh, H. F. Isleem, A. R. G. de Azevedo, H. U. Ahmed, and W. Emad, "Sustainable utilization of red mud waste (bauxite residue) and slag for the production of geopolymer composites: A review," Case Studies in Construction Materials, vol. 16, p. e00994, 2022/06/01/ 2022, doi: https://doi.org/10.1016/j.cscm.2022.e00994.

[80] S. N. Ahmed, N. H. Sor, M. A. Ahmed, and S. M. A. Qaidi, "Thermal conductivity and hardened behavior of eco-friendly concrete incorporating waste polypropylene as fine aggregate," Materials Today: Proceedings, 2022.

[81] S. Qaidi, "Ultra-high-performance fiber-reinforced concrete (UHPFRC): A mini-review of the challenges," ScienceOpen Preprints, doi: 10.14293/S2199-1006.1.SOR-.PPA6YEF.v1.

[82] S. Qaidi, "Ultra-High-Performance Fiber-Reinforced Concrete: Applications," Preprints, 2022, doi: http://dx.doi.org/10.20944/preprints202207.0271.v1.

[83] S. M. A. Qaidi, "Ultra-high-performance fiber-reinforced concrete: Applications," University of Duhok, Duhok, 2022.

[84] S. M. A. Qaidi, "Ultra-high-performance fiber-reinforced concrete: Challenges," University of Duhok, Duhok, 2022.

[85] J. Ye, W. Zhang, and D. Shi, "Effect of elevated temperature on the properties of geopolymer synthesized from calcined ore-dressing tailing of bauxite and ground-granulated blast furnace slag," Construction and Building Materials, vol. 69, pp. 41-48, 2014.