A critique on characterising interface resistances with maximum moisture flows

Abstract

In February 2018, this journal published the article "Interface influence on moisture transport in buildings". This critique firstly establishes that the reported 'hydric resistance' values overestimate the impacts of the material interfaces for the brick-mortar 'hydraulic contact' samples. It is shown that the actual flows after crossing the brick-mortar interface are 2 to 5 times higher than indicated by the article's 'hydric resistance' values. This critique secondly demonstrates that the article's main idea of characterising material interfaces with a maximal post-interface-flow is not dependable nor generalisable. This flow is not necessarily constant in time, and may depend on the interface's actual location, the surrounding materials' properties and the imposed boundary conditions, hence defying all generalisation. The conclusion of this critique is therefore that the processing methods and results of the disputed article are not reliable.

Does kaolin clay really create a perfect hydraulic interface contact between materials?

“…Does kaolin clay really create a perfect hydraulic interface contact between materials. Construction and Building Materials, Volume 262, 120700. https://doi.org/10.1016/j.conbuildmat.2020.120700 3 multi-layered building elements can differ from the moisture transfer observed for the combination of the separate materials due to interface phenomena such as a mismatch of the pore structure of the materials in contact, compaction pores, mortar particles that penetrate into the material in contact with, micro-cracks as well as a change in (glue) mortar properties [6,7,8,9,10,11,12,13]. This deviation is projected in a deceleration of the moisture transport across the material interface [14,15,16], as if a hydraulic interface resistance is present, and can influence risk assessments.…”