Real-time monitoring the electrical properties of pastes to map the hydration induced microstructure change in cement-based materials
Journal article, 2022

The effect of the supplementary materials (SCMs) on the moisture content and ion diffusivity at different hydration time is important for the service life modelling of modern concrete. This study designed a simple but valid method to monitor the microstructure change in pastes during hydration. A procedure easy to implement was proposed to detect the water content in pastes. The electrical conductivity of pore solution was evaluated by the evaporable water content in pastes and chemical composition in the binders. Results show that the electrical properties of pastes (conductivity, formation factor and its growth rate) can effectively indicate the hydration reactivity of binder, pore connectivity and volume of pore solution in the hardened pastes. The effect of waterbinder ratio and SCMs on the structure of pastes are effectively indexed by the formation factor which is the conductivity of pore solution divided by that of paste. The inflection point of average growth rate of formation factor is a good index for the final setting of pastes. The relation between volume of evaporable water and formation factor is well demonstrated by the extended percolation theory. The real-time monitored electrical conductivity and formation factor of pastes can be used to calculate the chloride migration coefficient in hardened cement pastes.

Electrical conductivity SCMs Formation factor Setting Percolation theory Chloride migration

Author

Liming Huang

Chalmers, Architecture and Civil Engineering, Building Technology

Tongji University

Luping Tang

Chalmers, Architecture and Civil Engineering, Building Technology

Ingemar Löfgren

Thomas Concrete Group

Chalmers, Architecture and Civil Engineering, Structural Engineering

Nilla Olsson

NCC Building Sweden

Zhenghong Yang

Tongji University

Cement and Concrete Composites

0958-9465 (ISSN)

Vol. 132 104639

Water in "Green" Cementitious Materials

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.

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

Driving Forces

Sustainable development

Subject Categories

Construction Management

Other Materials Engineering

Theoretical Chemistry

Roots

Basic sciences

Areas of Advance

Materials Science

DOI

10.1016/j.cemconcomp.2022.104639

More information

Latest update

8/29/2022