Development of phosphogypsum-based full-solid-waste cementitious materials: Mechanical properties, hydration mechanisms, and pollutant stabilization mechanisms

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F25%3A00383780" target="_blank" >RIV/68407700:21110/25:00383780 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1016/j.jobe.2025.113100" target="_blank" >https://doi.org/10.1016/j.jobe.2025.113100</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jobe.2025.113100" target="_blank" >10.1016/j.jobe.2025.113100</a>

Result language

angličtina

Original language name

Development of phosphogypsum-based full-solid-waste cementitious materials: Mechanical properties, hydration mechanisms, and pollutant stabilization mechanisms

Original language description

Phosphogypsum (PG), a byproduct of phosphate fertilizer production, contains multiple pollutants, and its improper disposal poses significant environmental and health risks. To mitigate these risks, this study leverages the sulfate-rich nature of PG by combining it with granulated blast furnace slag (GBFS), fly ash (FA), steel slag (SS), and carbide slag (CS) to develop fully solid-waste-based cementitious materials. Three PG-based formulations (PG+GBFS+CS, PG+FA+CS, and PG+SS+CS) were designed, and their mechanical performance, hydration behavior, and pollutant stabilization mechanisms were systematically investigated. The results reveal that CaSO4.2H2O in PG reacts effectively with the active SiO2 and Al2O3 in GBFS and the Ca(OH)2 in CS, generating substantial amounts of AFt and C-(A)-S-H gels, leading to a compact microstructure and reduced porosity. Consequently, the PG+GBFS+CS system exhibited the highest compressive strength, achieving 50.8 MPa at 28 days with an optimal mix of 55% PG, 44% GBFS, and 1% CS. In contrast, the lower reactivity and CaO content of FA and SS resulted in weaker interactions with PG, producing fewer hydration products, a looser microstructure, and lower strength in the PG+FA+CS and PG+SS+CS systems. Although the raw PG contained excessive levels of F, P, and As, the concentrations of all pollutants in the hardened PG-based materials complied with regulatory standards. The self-stabilization of pollutants was attributed to the hydration reactions of CS, GBFS, FA, and SS, which released OH- ions promoting the formation of insoluble hydroxide precipitates. Additionally, Ca2+ ions released during hydration facilitated the transformation of soluble pollutants into stable forms. The hydration products, including AFt, C-(A)-S-H, and AFm, further contributed to pollutant immobilization through ion exchange, adsorption, and encapsulation, ensuring that the leaching toxicity levels met the GB8978-1996 standard.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20101 - Civil engineering

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Building Engineering

ISSN

2352-7102

e-ISSN

2352-7102

Volume of the periodical

110

Issue of the periodical within the volume

113100

Country of publishing house

GB - UNITED KINGDOM

Number of pages

20

Pages from-to

—

UT code for WoS article

001507275800008

EID of the result in the Scopus database

2-s2.0-105007343954