Interlaboratory Comparison of Hygric Properties of Porous Building Materials

Abstract

The precision of methods used for the determination of hygric properties of porous building materials was investigated. The study was performed in the framework of the EU-initiated HAMSTAD-project. Six laboratories measured the selected hygric properties of three porous building materials. While the most measured properties show acceptable agreement, yet, it was found that some of the existing standards or commonly accepted measurement methods need improvement. Most striking were large variations in the results of the vapour transmission tests performed in accordance to the existing European Standard.

Sensitivity analysis of CFD coupled non-isothermal heat and moisture modelling

“…Sensitivity analysis Studies of [16] and [17] showed a large variability of measured material properties, which stresses the importance of a sensitivity analysis. The effect of changes in the material properties on the numerical results will be studied in this section.…”

“…Extensive databases for these material properties can be found in literature [6,15,16]. However, recent studies revealed a large spread of some of these material properties when the same material was measured by different laboratories [16,17]. It is often not clear how this will affect the model outcome.…”

Magnetic resonance imaging studies of spontaneous capillary water imbibition in aerated gypsum

“…This is consistent with the slow increase in water content, observed gravimetrically, after 50 minutes; see figure 4. This behaviour has been attributed previously to dissolution and removal of air [61]. Here, it is clear from the MRI profiles that the leading edge of the wetting front reaches the end of the sample at t = 50 minutes.…”

“…In this case, the correlation coefficient r = 0.998. The slower increase of water content after 50 minutes has been attributed to a dissolution and removal of air that is entrapped within the sample after the wetting front has reached the end of the sample [61].…”

Natural zeolite as environmentally friendly supplementary cementitious material in concrete

“…It took place in a conditioned laboratory at the temperature of 22±1°C and 25-30% relative humidity. [kgm -3 ] were determined by the water vacuum saturation method [9]. Each sample was dried in a drier to remove majority of the physically bound water.…”