Phosphogypsum Binder for Transport Construction

Phosphogypsum (PG) is a large-tonnage by-product of phosphate raw material processing in the manufacture of mineral fertilisers. This article examines two modifications of purified phosphogypsum binder with a predominant content of the α- and β-hemihydrate forms of calcium sulphate.
The accumulation of phosphogypsum in stockpiles poses a serious environmental threat. At the same time, transport construction, encompassing the building of roads, bridges, and tunnels, requires readily available and effective materials.
The objective of the work is to assess the potential of phosphogypsum as a binder for structural layers of road pavements, subbase courses, and low-criticality elements of transport structures by investigating the long-term kinetics of strength gain.
Experimental tests were conducted on 40×40×160 mm beam specimens made from β-PG, α-PG, α-PG with polypropylene fibres, and commercial gypsum (CG) as a reference material. Specimens were cured under standard conditions. Changes in average density, compressive strength, and flexural strength were measured at ages ranging from 2 hours to 90 days.
It was established that the most intensive evaporation of free water occurs within the first 7 days. The β-PG (a low-grade binder, G-2) exhibits a two-stage strength gain over 60 days, with a total compressive strength increase of 384% relative to the grade strength. The α-PG (binder G-10) also demonstrates a two-stage strength gain, but over 90 days, with a compressive strength increase of 99%. The addition of fibres does not increase grade strength but affects the kinetics of water evaporation. No strength reduction was observed during the monitoring period.

1. Ferronskaya A. V. (ed.) Gipsovye materialy i izdeliya (proizvodstvo i primenenie) [Gypsum materials and products (production and application)]. — Moscow: ASV Publ., 2004.— 488 p. (In Russ.)

2. Bilal E., Bellefqih H., Bourgier V. et al. Phosphogypsum circular economy considerations: a critical review from more than 65 storage sites worldwide // Journal of Cleaner Production.— 2023.—Vol. 414.—Art. 137561.

3. Maina L., Kiegiel K., Zakrzewska-Koltuniewicz G. Challenges and strategies for the sustainable environmental management of phosphogypsum // Sustainability. — 2025.— Vol. 17.—Art. 3473.

4. Okhinko V. A., Milovanov V. V. Aktualnye problemy ekologii i ekologicheskoj bezopasnosti i vozmozhnye puti ikh resheniya [Current problems of ecology and environmental safety and possible solutions] // Inzhenerno-stroitelnyj vestnik Prikaspiya [Engineering and Construction Bulletin of the Caspian Region]. — 2015. — No. 3 (13). — P. 37–38. (In Russ.)

5. Akfas F., Elghali A., Aboulaich A. et al. Exploring the potential reuse of phosphogypsum: A waste or a resource? // Science of the Total Environment.— 2024.— Vol. 908.—Art. 168196.

6. Sobol Yu. B., Abramov A. M., Polumiev E. V. Novye tekhnologicheskie podkhody v proizvodstve iskusstvennogo gipsovogo kamnya iz fosfogipsa [New technological approaches in the production of synthetic gypsum stone from phosphogypsum] // Stroitelnye materialy [Construction Materials]. — 2022.— No. 8.— P. 31–35. (In Russ.)

7. Bellefqih H., Bourgier V., Bilal E. et al. Effect of HPO4²⁻ and brushite on gypsum reactivity and implications for utilization of phosphogypsum in plaster production // Journal of Cleaner Production.— 2024.— Vol. 451.—Art. 142013.

8. Zhang J., Cui K., Chang J., Wang L. Phosphogypsum-based building materials: Resource utilization, development, and limitation // Journal of Building Engineering.— 2024.— Vol. 91.—Art. 109734.

9. Tararushkin E. V., Shchelokova T. N., Kudryavtseva V. D. A study of strength fluctuations of Portland cement by FTIR spectroscopy // IOP Conference Series: Materials Science and Engineering. — 2020. — Vol. 919. — Art. 022017. — DOI: 10.1088/1757–899X/919/2/022017.

10. Tararushkin E. V., Shchelokova T. N. Daily strength testing of the Portland cement mortars // IOP Conference Series: Materials Science and Engineering.— 2020.— Vol. 862.—Art. 022031.

11. Wei C., Gu J. Application of the industrial byproduct gypsum in building materials: A review // Materials. — 2024.— Vol. 17.—Art. 1837.

12. Yang J., Dong S., Ma L. et al. Review on high-value utilization of phosphogypsum: Utilization of calcium and oxygen resources present in phosphogypsum // Separation and Purification Technology. — 2024.— Vol. 344.—Art. 127246.

13. Wei Z., Deng Z. Research hotspots and trends of comprehensive utilization of phosphogypsum: Bibliometric analysis // Journal of Environmental Radioactivity.— 2022.—Vol. 242.—Art. 106778.

14. Bumanis G., Zorica J., Bajare D., Korjakins A. Technological properties of phosphogypsum binder obtained from fertilizer production waste // Energy Procedia. — 2018. — Vol. 147. — P. 301–308.

15. Alfimova N. I., Levitskaya K. M., Buryanov A. F. Ispolzovanie fosfogipsa kak syrya dlya proizvodstva mnogokomponentnykh vyazhushchikh i sulfoaluminatnykh tsementov [Use of phosphogypsum as raw material for multicomponent binders and sulfoaluminate cements] // Regionalnaya arkhitektura i stroitelstvo [Regional Architecture and Construction].— 2024.— No. 2 (59). — P. 30–46. (In Russ.)

16. Murakami K., Tanaka H., Sato K. Procedures for the chemical analysis of impurities of phosphogypsum // Gypsum & Lime.— 1967.— Vol. 91.— P. 249–255.

17. Provootorov A.A., Tararushkin E. V. Issledovanie kinetiki nabora prochnosti fosfogipsa [Study of phosphogypsum strength development kinetics] // Materialovedenie, formoobrazuyushchie tekhnologii i oborudovanie 2025 (ICMSSTE2025): Proceedings. — Simferopol: V. I. Vernadsky Crimean Federal University Publ., 2025.— P. 93–97. (In Russ.)

18. Lyashkevich I. M., Danko G., Raptunovich G. S. Structure and properties of pressed gypsum and gypsum-cement materials // Cement and Concrete Research.— 1990.—Vol. 20.— P. 357–368.

19. Nasirov R., Kopasheva A. A., Kuspanova B. K. Anion-radikaly organicheskikh soedinenij [Anion radicals of organic compounds] // Inzhenerno-stroitelnyj vestnik Prikaspiya. — 2012.— No. 2 (3). — P. 45–48. (In Russ.)

20. Sokolova Yu. A., Moreva I. V. Effektivnye kompozitsionnye materialy na osnove nizkomarochnogo stroitelnogo gipsa [Effective composite materials based on low-grade gypsum].— Moscow: Rusajns Publ., 2024.— 332 p. (In Russ.)

21. Kupchikova N. V., Antipova A. D. Analiz regionalnykh osobennostej proizvodstva energoeffektivnykh stroitelnykh materialov na osnove penostekla [Analysis of regional features of energy- efficient building materials based on foam glass] // Investitsii, stroitelstvo, nedvizhimost kak materialnyj bazis modernizatsii i innovatsionnogo razvitiya ekonomiki: Proceedings.— Tomsk: TSUAB Publ., 2016.— P. 444–448. (In Russ.)

22. Kupchikova N. V., Shayakhmedov R. I., Antipova A. D. Sposob polucheniya stroitelnykh izdelij iz shlakositalla [Method for producing construction products from slag sitall]. — Patent RF No. 2669020 C1, IPC C03B32/00. — Filed 31.07.2017; publ. 05.10.2018. —Applicant: Astrakhan State University of Architecture and Civil Engineering. (In Russ.)