Real-time monitoring the electrical properties of pastes to map the hydration induced microstructure change in cement-based materials
Artikel i vetenskaplig tidskrift, 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

Författare

Liming Huang

Chalmers, Arkitektur och samhällsbyggnadsteknik, Byggnadsteknologi

Tongji University

Luping Tang

Chalmers, Arkitektur och samhällsbyggnadsteknik, Byggnadsteknologi

Ingemar Löfgren

Thomas Concrete Group

Chalmers, Arkitektur och samhällsbyggnadsteknik, Konstruktionsteknik

Nilla Olsson

NCC Building Sweden

Zhenghong Yang

Tongji University

Cement and Concrete Composites

0958-9465 (ISSN)

Vol. 132 104639

Vatten i "gröna" cementmaterial

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

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

Svenska Byggbranschens Utvecklingsfond (SBUF), 2019-01-01 -- 2022-04-30.

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

Drivkrafter

Hållbar utveckling

Ämneskategorier

Byggproduktion

Annan materialteknik

Teoretisk kemi

Fundament

Grundläggande vetenskaper

Styrkeområden

Materialvetenskap

DOI

10.1016/j.cemconcomp.2022.104639

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Senast uppdaterat

2022-08-29