Experimental assessment of the variability of concrete air permeability: repeatability, reproducibility and spatial variability

N. Issaadi (1) , A.A. A Hamami (1) , Rafik Belarbi (1) , A. Aït-Mokhtar (1)

1 LaSIE - Laboratoire des Sciences de l'Ingénieur pour l'Environnement - UMR 7356

To study the effect of spatial variability of some influential parameters on the durability of the building envelopes, some important information are required: the mean, the standard deviation and the spatial correlation of the studied fields defined by the correlation lengths. In this paper, the characterization of the concrete spatial variability was performed which included a significant number of test allowing the characterization of concrete air permeability. For this a concrete wall of 2 m of height, 1.20 m of width and 15 cm of thickness was manufactured in laboratory in which concrete specimens were periodically taken and tested. Firstly, results repeatability was performed. For these purpose, three tests per sample was carried out in order to assess the repeatability of the measurements. Secondly, the reproducibility of the measurements was carried out by testing two samples for each cored specimen. Good repeatability of the intrinsic permeability measurements on each tested sample is recorded. Indeed, the standard deviation does not exceed 0.67x10–17 m². Also, the concrete intrinsic permeability depends on the spatial location of the studied sample. It was found to be ranging between 2.38x10-17 and 5.91x10-17 m2 with an average value equal to 3.66x10-17 m2. The obtained results enable to quantify the spatial variability of concrete air permeability, particularly in terms of mean value and standard deviation. Also, it allowed highlighting the spatial correlation length of the studied fields and for probabilistic approaches regarding the prediction of the concrete durability.

Mots clés: air permeability; correlation length; Climate change; Concrete; Forecast; statistical function; Heat demand; spatial variability

Domaines: Matériaux composites et construction; Construction durable; Thermique [physics.class-ph]

N. Issaadi, A.A. A Hamami, Rafik Belarbi, A. Aït-Mokhtar. Experimental assessment of the variability of concrete air permeability: repeatability, reproducibility and spatial variability. Energy Procedia, 2017, 139, pp.537-543. ⟨10.1016/j.egypro.2017.11.250⟩. ⟨hal-02076072⟩