{"title":"1H LF-NMR study on water migration behavior of fresh cement paste with limestone powder","authors":"Jing Qiao , Chunsheng Zhou , Jingjing Feng , Miao Miao , Yanliang Ji , Linan Gu","doi":"10.1016/j.cemconres.2025.107802","DOIUrl":null,"url":null,"abstract":"<div><div>Limestone powder (LS) with large particle sizes is widely used, but its effect on water migration behavior remains unclear. This study investigates the influence of LS and viscosity-enhancing admixtures (VEAs) on the water migration behavior and water distribution in fresh cement paste using <sup>1</sup>H low-field nuclear magnetic resonance (LF-NMR). Results indicate that LS increases the size of water migration channels, accelerates the water migration rate, and raises the bleeding ratio, while VEAs substantially mitigate the effects of LS. Compared to polyacrylamide, cellulose ether significantly slows down the water migration rate before 40 min, thereby reducing the bleeding ratio. Additionally, relaxation times were found to decrease during bleeding and can reflect the sedimentation process. It is confirmed that the pore structure of fresh paste exhibits fractal characteristics, with the fractal dimension closely correlating with water migration rates. The underlying mechanisms and their implications on material behavior are thoroughly analyzed and discussed.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"191 ","pages":"Article 107802"},"PeriodicalIF":10.9000,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement and Concrete Research","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0008884625000213","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
Limestone powder (LS) with large particle sizes is widely used, but its effect on water migration behavior remains unclear. This study investigates the influence of LS and viscosity-enhancing admixtures (VEAs) on the water migration behavior and water distribution in fresh cement paste using 1H low-field nuclear magnetic resonance (LF-NMR). Results indicate that LS increases the size of water migration channels, accelerates the water migration rate, and raises the bleeding ratio, while VEAs substantially mitigate the effects of LS. Compared to polyacrylamide, cellulose ether significantly slows down the water migration rate before 40 min, thereby reducing the bleeding ratio. Additionally, relaxation times were found to decrease during bleeding and can reflect the sedimentation process. It is confirmed that the pore structure of fresh paste exhibits fractal characteristics, with the fractal dimension closely correlating with water migration rates. The underlying mechanisms and their implications on material behavior are thoroughly analyzed and discussed.
期刊介绍:
Cement and Concrete Research is dedicated to publishing top-notch research on the materials science and engineering of cement, cement composites, mortars, concrete, and related materials incorporating cement or other mineral binders. The journal prioritizes reporting significant findings in research on the properties and performance of cementitious materials. It also covers novel experimental techniques, the latest analytical and modeling methods, examination and diagnosis of actual cement and concrete structures, and the exploration of potential improvements in materials.