{"title":"水压对混凝土中孔隙结构演变和氯离子迁移的影响","authors":"Jie Chen, Jin Xia, Renjie Wu, Yu Peng","doi":"10.1680/jmacr.23.00283","DOIUrl":null,"url":null,"abstract":"To study the influence of hydraulic pressure on pore structure evolution and chloride transport behavior in concrete, the mass transport depth, chloride concentration, and pore characteristics of specimens with different water-cement ratios were investigated using silver nitrate spraying, potentiometric titration, the mercury intrusion porosimetry (MIP) method, N2 adsorption method, and laser confocal microscopy. The results showed that chloride concentration increases as the hydraulic pressure and the water-cement ratio increase. As this hydraulic pressure increases, the difference between water and chloride ion transport distinctive characteristics becomes conspicuously pronounced, extending from 5.2 mm to 25.4 mm in distance. The hydraulic pressure changes the pore structure of the concrete, leading to a surge in the specific surface area, larger porosity, and average pore diameters. Notably, ink-bottle-type pores emerge prominently and the proportion of fine mesopores and capillary pores markedly rises after the application of hydraulic pressure. Furthermore, a relationship between chloride diffusion coefficient and hydraulic pressure is suggested. A relationship between the modified permeability coefficient and hydraulic pressure is constructed based on the mesoporous contribution β to express the hysteresis effect of chloride.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Influence of hydraulic pressure on pore structure evolution and chloride transport in concrete\",\"authors\":\"Jie Chen, Jin Xia, Renjie Wu, Yu Peng\",\"doi\":\"10.1680/jmacr.23.00283\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"To study the influence of hydraulic pressure on pore structure evolution and chloride transport behavior in concrete, the mass transport depth, chloride concentration, and pore characteristics of specimens with different water-cement ratios were investigated using silver nitrate spraying, potentiometric titration, the mercury intrusion porosimetry (MIP) method, N2 adsorption method, and laser confocal microscopy. The results showed that chloride concentration increases as the hydraulic pressure and the water-cement ratio increase. As this hydraulic pressure increases, the difference between water and chloride ion transport distinctive characteristics becomes conspicuously pronounced, extending from 5.2 mm to 25.4 mm in distance. The hydraulic pressure changes the pore structure of the concrete, leading to a surge in the specific surface area, larger porosity, and average pore diameters. Notably, ink-bottle-type pores emerge prominently and the proportion of fine mesopores and capillary pores markedly rises after the application of hydraulic pressure. Furthermore, a relationship between chloride diffusion coefficient and hydraulic pressure is suggested. A relationship between the modified permeability coefficient and hydraulic pressure is constructed based on the mesoporous contribution β to express the hysteresis effect of chloride.\",\"PeriodicalId\":18113,\"journal\":{\"name\":\"Magazine of Concrete Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.8000,\"publicationDate\":\"2024-03-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Magazine of Concrete Research\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://doi.org/10.1680/jmacr.23.00283\",\"RegionNum\":4,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CONSTRUCTION & BUILDING TECHNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Magazine of Concrete Research","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1680/jmacr.23.00283","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
Influence of hydraulic pressure on pore structure evolution and chloride transport in concrete
To study the influence of hydraulic pressure on pore structure evolution and chloride transport behavior in concrete, the mass transport depth, chloride concentration, and pore characteristics of specimens with different water-cement ratios were investigated using silver nitrate spraying, potentiometric titration, the mercury intrusion porosimetry (MIP) method, N2 adsorption method, and laser confocal microscopy. The results showed that chloride concentration increases as the hydraulic pressure and the water-cement ratio increase. As this hydraulic pressure increases, the difference between water and chloride ion transport distinctive characteristics becomes conspicuously pronounced, extending from 5.2 mm to 25.4 mm in distance. The hydraulic pressure changes the pore structure of the concrete, leading to a surge in the specific surface area, larger porosity, and average pore diameters. Notably, ink-bottle-type pores emerge prominently and the proportion of fine mesopores and capillary pores markedly rises after the application of hydraulic pressure. Furthermore, a relationship between chloride diffusion coefficient and hydraulic pressure is suggested. A relationship between the modified permeability coefficient and hydraulic pressure is constructed based on the mesoporous contribution β to express the hysteresis effect of chloride.
期刊介绍:
For concrete and other cementitious derivatives to be developed further, we need to understand the use of alternative hydraulically active materials used in combination with plain Portland Cement, sustainability and durability issues. Both fundamental and best practice issues need to be addressed.
Magazine of Concrete Research covers every aspect of concrete manufacture and behaviour from performance and evaluation of constituent materials to mix design, testing, durability, structural analysis and composite construction.