Modern approach to surface layer modifications of hydrated cement paste for improving permeability estimates of virtual concrete

Permeability estimates obtained by physical experiments and by simulations differ quite significantly. When biases at the experimental side would be eliminated, the expected modest gap could be bridged by surface layer modifications of the hardened cement paste, discussed herein. This involves the formation of a fractal-like nano-particle...

Cauchy-based modelling in cementitious materials technology

Cauchy paved the way for constructing models in concrete technology, and elsewhere. He determined the (non-flat) surface area in 3D by measuring random total projections. Analogously, he determined the length of a curved line in 2D by way of measuring the total projections. The paper will present the mathematical expressions, because in many...

Systematic research on compucrete can shed light on some controversial issues in concrete technology

Realistically simulating fresh and hardening cementitious materials renders possible understanding controversial issues existing in the field of concrete technology. The experimental studies on the impact of the interfacial transition zone (ITZ) on permeability of concrete reveal two controversial results. The first involves the concept of...

Demonstration and validation by simple examples of a complete analogue porosimetry methodology for virtual cement pastes on micro-level

Details of a complete methodology for porosimetry of virtual concrete have been described in a series of publications. This paper shortly sketches the main characteristics, whereupon it is indicated how a pore network model is designed based on data extracted from the virtual cement paste. This involves smoothing the main trunks as the main pore...

Liquid water permeability of partially saturated cement paste assessed by dem-based methodology

Permeability of virtual cement seems to exceed experimental data by several orders of magnitude. The differences may actually not be that dramatic, since experimental samples are in practice not always fully saturated as generally assumed. This paper demonstrates that this has enormous effects on permeability. A numerical study is conducted on...

Methodolody for porosimetry in virtual cementitious composites to economically and reliably estimate permeability

A novel methodology is described for porosimetry as well as for water transport through the pore system in dynamic DEM-based virtual cementitious materials. The pore network topology, the pore size distribution and the pore connectivity are assessed on the basis of a robotics-inspired pore delineation method and star volume measurements....