{"title":"Effect of modifiers on the properties of bamboo scraps/magnesium oxychloride composites under dry-wet cycling environments","authors":"Shanshan Wu , Qiang Fang , Huagang Zhang , Jiaojiao Yang , Zhengrong Zhou","doi":"10.1016/j.cscm.2024.e03504","DOIUrl":null,"url":null,"abstract":"<div><p>Bamboo scraps/magnesium oxychloride composites (BS/MOC) is a new low-carbon and eco-friendly building material, which is composed of magnesium oxychloride cement (MOC) as the matrix and bamboo scraps as the reinforcing materials. However, the poor strength and durability of BS/MOC under special environmental conditions seriously restrict its application range. To solve the above problems, citric acid (CA), D-gluconic acid sodium salt (GS), and styrene-acrylate emulsion (SAE) were used as modifiers to improve BS/MOC properties. The effect of modifier addition on the mechanical strength and durability of BS/MOC was investigated under dry-wet cycling environments. The phase composition, microstructure, pore structure, and Clˉ concentration of BS/MOC were characterized by XRD, TGA, SEM, MIP, and ICS-600. The results showed that CA and GS improved the interface adhesion between bamboo scraps and MOC matrix, and both inhibited the hydration reaction of the residual MgO and the hydrolysis of phase 5 crystals, resulting in good mechanical properties and microstructural stability of BS/MOC under dry-wet cycles. GS outperformed CA in refining pore structure, improving mechanical properties and durability of BS/MOC under identical dry-wet cycles. Conversely, the addition of SAE increased initial defects and interfacial transition zones in the BS/MOC matrix, and increased the total porosity and the harmful pores content, which negatively affected the mechanical properties and durability of BS/MOC.</p></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":null,"pages":null},"PeriodicalIF":6.5000,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2214509524006557/pdfft?md5=5bdb36bd8eae1ae08a846d2cc4660b8f&pid=1-s2.0-S2214509524006557-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Case Studies in Construction Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214509524006557","RegionNum":2,"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
Bamboo scraps/magnesium oxychloride composites (BS/MOC) is a new low-carbon and eco-friendly building material, which is composed of magnesium oxychloride cement (MOC) as the matrix and bamboo scraps as the reinforcing materials. However, the poor strength and durability of BS/MOC under special environmental conditions seriously restrict its application range. To solve the above problems, citric acid (CA), D-gluconic acid sodium salt (GS), and styrene-acrylate emulsion (SAE) were used as modifiers to improve BS/MOC properties. The effect of modifier addition on the mechanical strength and durability of BS/MOC was investigated under dry-wet cycling environments. The phase composition, microstructure, pore structure, and Clˉ concentration of BS/MOC were characterized by XRD, TGA, SEM, MIP, and ICS-600. The results showed that CA and GS improved the interface adhesion between bamboo scraps and MOC matrix, and both inhibited the hydration reaction of the residual MgO and the hydrolysis of phase 5 crystals, resulting in good mechanical properties and microstructural stability of BS/MOC under dry-wet cycles. GS outperformed CA in refining pore structure, improving mechanical properties and durability of BS/MOC under identical dry-wet cycles. Conversely, the addition of SAE increased initial defects and interfacial transition zones in the BS/MOC matrix, and increased the total porosity and the harmful pores content, which negatively affected the mechanical properties and durability of BS/MOC.
期刊介绍:
Case Studies in Construction Materials provides a forum for the rapid publication of short, structured Case Studies on construction materials. In addition, the journal also publishes related Short Communications, Full length research article and Comprehensive review papers (by invitation).
The journal will provide an essential compendium of case studies for practicing engineers, designers, researchers and other practitioners who are interested in all aspects construction materials. The journal will publish new and novel case studies, but will also provide a forum for the publication of high quality descriptions of classic construction material problems and solutions.