Naslov
3D modeling of transport properties of cementitious materials

Autori
Ukrainczyk, Neven

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
63rd Microlab Colloquium

Mjesto i datum
Delft, Nizozemska, 31.01.2013

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Cementitious materials; durability; 3D modeling; multi*scale modeling; effective diffusion; hydration reactions; microstructure;

Sažetak
Results of the project sponsored by Marie Curie Actions EU grant FP7-PEOPLE-2010-IEF-272653-DICEM: 'Diffusion of Ions in Cementitious Materials' are presented. Transport processes in cementitious materials play a crucial role in both the degradation process of building materials as well as in the containment of hazardous wastes. Replacement of cement by pozzolanic waste materials, being a by-product from industrial processes, has been widely recognized as the most promising route towards sustainable construction materials. In order to contribute to a such development, this post-doc research at Microlab is focused on: 1) hydration of blended cements, and 2)modelling of transport properties of cementitious materials, needed to assess the durability performance of this class of sustainable cementitious materials. A novel multi-component model for blended cement hydration reactions implemented within Hymostruc model is presented. As part of this, the simultaneous reaction kinetics of four principal clinker minerals and pozzolans, were coupled to the microstructural development. A multi-scale nature of cementitious materials possesses a great challenge to the modelling of their properties. A 3D finite difference module was developed to estimate the effective transport properties. The influence of the initial particle size distribution, the hydration evolution and the numerical resolution was investigated, resulting in 300 sets of numerical assessments for the effective diffusivity. The connectivity of the capillary pores was evaluated with the 3D flood fill algorithm. Within the project a novel image based numerical method to obtain a pore size distribution of cementitious materials from 3D digital images is proposed. Moreover, an innovative multi-scale approach has been developed to mitigate the resolution problems in numerical methods necessary to calculate the effective transport properties of porous materials using 3D digital images. The new approach significantly reduces computational efforts and improves the accuracy of the transport property estimation. Numerical results are compared with experimental observations, demonstrating the potential of implemented models to simulate hydration reactions and corresponding microstructural changes in so-called blended cement systems.

Izvorni jezik
Engleski

Znanstvena područja
Građevinarstvo, Kemijsko inženjerstvo, Temeljne tehničke znanosti

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