Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions

This research examines the impact of sulphate on pore water pressure (PWP) development in cement paste backfill (CPB) containing polycarboxylate ether (PES) superplasticizers under thermal-hydraulic-mechanical-chemical (THMC) conditions that imitate actual field curing scenarios. PWP in CPB-PES, wit...

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Main Authors: Zubaida Al-Moselly, Mamadou Fall
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Journal of Rock Mechanics and Geotechnical Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S1674775525000174
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author Zubaida Al-Moselly
Mamadou Fall
author_facet Zubaida Al-Moselly
Mamadou Fall
author_sort Zubaida Al-Moselly
collection DOAJ
description This research examines the impact of sulphate on pore water pressure (PWP) development in cement paste backfill (CPB) containing polycarboxylate ether (PES) superplasticizers under thermal-hydraulic-mechanical-chemical (THMC) conditions that imitate actual field curing scenarios. PWP in CPB-PES, with and without sulphate, was assessed under non-isothermal field curing temperatures, varied drainage conditions, and curing stresses using a specially experimental setup. Key findings indicate that PWP behavior in CPB with PES under field conditions diverges markedly from standard laboratory conditions due to the significant effects of field curing temperatures, drainage conditions, and backfill self-weight. The study establishes that high sulphate ion concentrations notably increase initial PWP and slow its dissipation by interfering with the cement hydration process. This interference delays hydration, reduces pore water consumption, and lowers capillary pressure. Moreover, the results show that THMC conditions, especially non-isothermal field temperatures and varied drainage scenarios, considerably accelerate cement hydration compared to standard laboratory conditions, resulting in a more rapid decrease in PWP. Furthermore, improved drainage under THMC conditions mitigates the adverse effects of sulphates by facilitating sulphate ion removal, thus supporting more efficient cement hydration and CPB self-desiccation. The insights gained from this research are essential for understanding PWP behavior in sulphate-bearing CPB-PES in the field, developing predictive THMC models for backfill performance assessment, and enhancing the safety and effectiveness of mining backfills.
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spelling doaj-art-f55faf9347444e89891a9b51ab4b4cbd2025-08-20T03:40:41ZengElsevierJournal of Rock Mechanics and Geotechnical Engineering1674-77552025-08-011784673468410.1016/j.jrmge.2024.11.046Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditionsZubaida Al-Moselly0Mamadou Fall1Department of Civil Engineering, University of Ottawa, Ottawa, ON K1N 6N5, CanadaCorresponding author.; Department of Civil Engineering, University of Ottawa, Ottawa, ON K1N 6N5, CanadaThis research examines the impact of sulphate on pore water pressure (PWP) development in cement paste backfill (CPB) containing polycarboxylate ether (PES) superplasticizers under thermal-hydraulic-mechanical-chemical (THMC) conditions that imitate actual field curing scenarios. PWP in CPB-PES, with and without sulphate, was assessed under non-isothermal field curing temperatures, varied drainage conditions, and curing stresses using a specially experimental setup. Key findings indicate that PWP behavior in CPB with PES under field conditions diverges markedly from standard laboratory conditions due to the significant effects of field curing temperatures, drainage conditions, and backfill self-weight. The study establishes that high sulphate ion concentrations notably increase initial PWP and slow its dissipation by interfering with the cement hydration process. This interference delays hydration, reduces pore water consumption, and lowers capillary pressure. Moreover, the results show that THMC conditions, especially non-isothermal field temperatures and varied drainage scenarios, considerably accelerate cement hydration compared to standard laboratory conditions, resulting in a more rapid decrease in PWP. Furthermore, improved drainage under THMC conditions mitigates the adverse effects of sulphates by facilitating sulphate ion removal, thus supporting more efficient cement hydration and CPB self-desiccation. The insights gained from this research are essential for understanding PWP behavior in sulphate-bearing CPB-PES in the field, developing predictive THMC models for backfill performance assessment, and enhancing the safety and effectiveness of mining backfills.http://www.sciencedirect.com/science/article/pii/S1674775525000174Cemented paste backfill (CPB)TailingsMineSulphatePore water pressureThermo-hydro-mechanical-chemical (THMC)
spellingShingle Zubaida Al-Moselly
Mamadou Fall
Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions
Journal of Rock Mechanics and Geotechnical Engineering
Cemented paste backfill (CPB)
Tailings
Mine
Sulphate
Pore water pressure
Thermo-hydro-mechanical-chemical (THMC)
title Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions
title_full Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions
title_fullStr Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions
title_full_unstemmed Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions
title_short Understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo-hydro-mechanical-chemical field conditions
title_sort understanding pore water pressure responses to sulphate in cemented tailings backfill with superplasticizers under thermo hydro mechanical chemical field conditions
topic Cemented paste backfill (CPB)
Tailings
Mine
Sulphate
Pore water pressure
Thermo-hydro-mechanical-chemical (THMC)
url http://www.sciencedirect.com/science/article/pii/S1674775525000174
work_keys_str_mv AT zubaidaalmoselly understandingporewaterpressureresponsestosulphateincementedtailingsbackfillwithsuperplasticizersunderthermohydromechanicalchemicalfieldconditions
AT mamadoufall understandingporewaterpressureresponsestosulphateincementedtailingsbackfillwithsuperplasticizersunderthermohydromechanicalchemicalfieldconditions