Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6717681 | Construction and Building Materials | 2018 | 8 Pages |
Abstract
This paper aims to study the influence of polycarboxylate superplasticizer on chloride binding in cement paste. The equilibrium isotherms, kinetics and thermodynamics of chloride ions binding in cement with different contents of polycarboxylate superplasticizer were thoroughly examined. It has been found that all of the equilibrium isotherms data can be well fitted by the Langmuir isotherm and Freundlich isotherm. However, the amount of chloride equilibrium binding is decreased with the increase of polycarboxylate superplasticizer content. The kinetic data in the initial 24â¯h is well described by pseudo-first-order kinetic model and pseudo-second-order model is well suitable to describe the long-period adsorption kinetics data. The rate of chloride binding within 24â¯h is decreased with the increase of polycarboxylate superplasticizer content. The negative value of free energy, enthalpy and entropy of chloride binding are increased with the content of polycarboxylate superplasticizer, and the process of chloride binding in cement paste is spontaneous and exothermic. Based on the above results, the 'electrical double layer' model is used to describe the influence of polycarboxylate superplasticizer on chloride binding in cement paste.
Related Topics
Physical Sciences and Engineering
Engineering
Civil and Structural Engineering
Authors
Wei Feng, Jinxia Xu, Ping Chen, Linhua Jiang, Yingbin Song, Yalong Cao,