Modelling the diffusivity of mortar and concrete using a three-dimensional mesostructure with several aggregate shapes
By S. D. Abyaneh, H. Wong, N. Buenfeld. 2013
181 citations recorded by the source corpus.
Abstract This paper presents a numerical investigation into the effect of ITZ and aggregate shape on the diffusivity of mortar and concrete using a three-dimensional model. Concrete is treated as a three-phase composite consisting of aggregate particles, bulk cement paste and aggregate–paste interface, i.e. the ‘interfacial transition zone’ (ITZ). The model is set up in two stages. First, a three-dimensional representative volume element of the concrete mesostructure is generated. Then, a finite difference method is used to simulate molecular diffusion through the mesostructure. The transport properties of the conductive phases (bulk cement paste and ITZ) are determined based on the water/cement ratio, degree of hydration and porosity gradients away from aggregate particles. The model is validated against available experimental data and compared with analytical relationships for ideal cases. The model is then used to study the effect of aggregate shape on diffusivity, which has not been attempted before in three-dimensions. The model is also applied to assess the effects of water/cement ratio, degree of hydration, aggregate size, volume fraction, shape and orientation, ITZ width and percolation on diffusivity. Some of these effects are impractical to quantify from laboratory experimentation alone. It was found that the shape and orientation of aggregate particles have a significant effect on diffusivity. Diffusivity decreased when spherical aggregate particles are replaced with ellipsoidal particles due to the consequent increase in tortuosity of the cement paste.
Subfields: Civil and Structural Engineering, Pollution
View Paper: https://www.semanticscholar.org/paper/74e58b0d3da0f3ba989fc3312b98b8554384a9ef
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Civil and Structural Engineering
In Pollution
- Jian Yang
- Qing-feng Liu
- H. Wong
- N. Buenfeld
- Long-yuan Li
- Guang Ye
- Dave Easterbrook
- Klaas van Breugel
Citations in the corpus
- Ionic transport features in concrete composites containing various shaped aggregates: a numerical study (2018, methodology): “The previous studies on the effect of aggregate shape [39,47] did not discuss or show the details of chloride transport in concrete, such as the time-dependent concentration distribution and penetration depth (which are the key information for predicting the depassivation process or chloride diffusi”
- Diffusivity of saturated ordinary Portland cement-based materials: A critical review of experimental and analytical modelling approaches (2016, background): “Similarly, diffusivity of mortar and concrete has been determined explicitly from the meso-structure [34,35].”
- Aggregate shape effect on the diffusivity of mortar (2014, methodology): “Simulations in literature [45,53] indicated that the predicted transport property increases when smaller voxels are used, because the aggregate shape and the connectivity between the ITZ voxels are better represented.”
- Transport properties of concrete after drying-wetting regimes to elucidate the effects of moisture content, hysteresis and microcracking (2017, result): “This shows that the effects of dilution (decrease in total porosity) and increase in cement paste tortuosity outweighs that of the porous ITZ, consistent with earlier studies [33, 34].”
- A three-phase, multi-component ionic transport model for simulation of chloride penetration in concrete (2015, methodology): “developed a 3-D, 3-phase FEA model to investigate the effects of aggregates including the aspect-ratio and orientation of ellipse shape aggregates and ITZs on the diffusion coefficient of chlorides in concrete [44].”