Using water vapour and N2 isotherms to unveil effects of SCMs on nanopores and evaluate hydration degree
Journal article, 2023

Nanopores are critical for the durability of cement-based materials, but the refinement of these pores by SCMs is yet to have a clear understanding. This paper studied effects of the water–binder ratio, SCMs and the drying on the distribution of nanopores using water vapour and N2 sorption isotherms. Results show that data of water vapour sorption can be used for a practical evaluation of the hydration degree of SCMs with thermodynamic simulation. Fly ash increases the volume of large gel and capillary pores. It lowers the difference between the sorption of water vapour and N2. Slag evidently refines the nanopores by increasing the volume of ink-bottle gel pores with an interlayer-size neck. A higher w/b produces more large pores to reduce the effect of drying. Removal of water induces contraction of interlayer and reduces gel pores volume, which causes large difference between sorption of water vapour and N2.


Water vapour sorption

Pore structure

Supplementary cementitious materials

Hydration degree


Liming Huang

Chalmers, Architecture and Civil Engineering, Building Technology

Luping Tang

Chalmers, Architecture and Civil Engineering, Building Technology

Lars Wadsö

Lund University

Ingemar Löfgren

Chalmers, Architecture and Civil Engineering, Structural Engineering

Nilla Olsson

NCC Building Sweden

Zhenghong Yang

Tongji University

Cement and Concrete Research

0008-8846 (ISSN)

Vol. 164 February 2023 107042

Water in "Green" Cementitious Materials

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

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

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

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

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Sustainable development

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Construction Management

Other Materials Engineering

Theoretical Chemistry


Basic sciences

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Materials Science



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