Thermodynamical analysis of the impact of chloride-rich environment on the paste mineralogy of magnesium phosphate cement

IF 10.8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites Pub Date : 2025-03-22 DOI:10.1016/j.cemconcomp.2025.106061

Weiwei Han , Huisu Chen , Shaomin Song

{"title":"Thermodynamical analysis of the impact of chloride-rich environment on the paste mineralogy of magnesium phosphate cement","authors":"Weiwei Han , Huisu Chen , Shaomin Song","doi":"10.1016/j.cemconcomp.2025.106061","DOIUrl":null,"url":null,"abstract":"<div><div>Magnesium phosphate cement (MPC) is commonly used as rapid repair materials for damaged pavements. MPC together with pavements usually undergoes de-icing salts exposure in winter. However, the deterioration mechanism of MPC under chloride attack remains unclear. A thermodynamic simulation approach was employed to investigate the deterioration mechanism of MPC. The results revealed that compressive strength loss decreases with the increase of the concentration of the NaCl solution. Basic magnesium chlorides cannot be formed in MPC immersed in NaCl solutions. The formed MgNH4PO4·6H2O, MgKPO4·6H2O and part of the residual magnesia can dissolve in NaCl solution, facilitating the precipitation of NH4NaMg2(PO4)2·14H2O, KNaMg2(PO4)2·14H2O and brucite in MPC. Due to the precipitation of NH4NaMg2(PO4)2·14H2O and KNaMg2(PO4)2·14H2O, the volume of solid phases increases slightly and then decreases under chloride attack. NH4NaMg2(PO4)2·14H2O and KNaMg2(PO4)2·14H2O are more soluble in concentrated NaCl solution, leading to the solid volume decrease of the hardened binder phases of MPC.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106061"},"PeriodicalIF":10.8000,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement & concrete composites","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S095894652500143X","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Magnesium phosphate cement (MPC) is commonly used as rapid repair materials for damaged pavements. MPC together with pavements usually undergoes de-icing salts exposure in winter. However, the deterioration mechanism of MPC under chloride attack remains unclear. A thermodynamic simulation approach was employed to investigate the deterioration mechanism of MPC. The results revealed that compressive strength loss decreases with the increase of the concentration of the NaCl solution. Basic magnesium chlorides cannot be formed in MPC immersed in NaCl solutions. The formed MgNH₄PO₄·6H₂O, MgKPO₄·6H₂O and part of the residual magnesia can dissolve in NaCl solution, facilitating the precipitation of NH₄NaMg₂(PO₄)₂·14H₂O, KNaMg₂(PO₄)₂·14H₂O and brucite in MPC. Due to the precipitation of NH₄NaMg₂(PO₄)₂·14H₂O and KNaMg₂(PO₄)₂·14H₂O, the volume of solid phases increases slightly and then decreases under chloride attack. NH₄NaMg₂(PO₄)₂·14H₂O and KNaMg₂(PO₄)₂·14H₂O are more soluble in concentrated NaCl solution, leading to the solid volume decrease of the hardened binder phases of MPC.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Cement & concrete composites 工程技术-材料科学：复合

CiteScore

18.70

自引率

11.40%

发文量

459

审稿时长

65 days

期刊介绍： Cement & concrete composites focuses on advancements in cement-concrete composite technology and the production, use, and performance of cement-based construction materials. It covers a wide range of materials, including fiber-reinforced composites, polymer composites, ferrocement, and those incorporating special aggregates or waste materials. Major themes include microstructure, material properties, testing, durability, mechanics, modeling, design, fabrication, and practical applications. The journal welcomes papers on structural behavior, field studies, repair and maintenance, serviceability, and sustainability. It aims to enhance understanding, provide a platform for unconventional materials, promote low-cost energy-saving materials, and bridge the gap between materials science, engineering, and construction. Special issues on emerging topics are also published to encourage collaboration between materials scientists, engineers, designers, and fabricators.