Distribution and dynamics of water in the blended pastes unraveled by thermoporometry and dielectric properties
Journal article, 2023

Water distribution in hardened paste and its dynamics determine many properties related to durability. Moisture distribution was determined by thermoporometry combined with vacuum drying. Dynamics of confined water were measured by broadband dielectric spectroscopy. Water in pores <2.4 nm cannot form tetrahedral ice structure due to geometrical constraints. The volume of unfrozen water (in interlayer and gel pores) decreases after the drying at all relative humidity levels. An evident coarsening of gel pores occurs with drying between 75 % and 55 % RH. 35 % fly ash and slag have limited effects on relaxation processes of silanol hydroxyl groups and interlayer water. However, they slow down the dynamics of water in small gel pores, thereby enhancing interactions between water and the solid interface. This study clarifies the microstructural changes during the drying and reveals the sensitivity of water dynamics to the chemical environment in C-S-H of blended pastes.

C-S-H

Water dynamics

Moisture distribution

SCMs

Dielectric relaxation

Author

Liming Huang

Tongji University

Chalmers, Architecture and Civil Engineering, Building Technology

Helen Jansson

Chalmers, Architecture and Civil Engineering, Building Technology

Jan Swenson

Chalmers, Physics, Nano and Biophysics

Luping Tang

Chalmers, Architecture and Civil Engineering, Building Technology

Zhenghong Yang

Tongji University

Cement and Concrete Research

0008-8846 (ISSN)

Vol. 174 107333

Water in "Green" Cementitious Materials

Cementa (173015), 2020-11-02 -- 2022-04-30.

Thomas Concrete Group, 2019-01-01 -- 2022-04-30.

Formas (2018-01430), 2019-01-02 -- 2022-04-30.

Development Fund of the Swedish Construction Industry (SBUF), 2019-01-01 -- 2022-04-30.

Subject Categories

Physical Chemistry

DOI

10.1016/j.cemconres.2023.107333

More information

Latest update

9/26/2023