%0 Journal Article
%T COMPARATIVE ANALYSIS OF DESORPTIVE METHODS USED FOR MASS DIFFUSIVITY ESTIMATION
%A Halina GarbaliĆska
%J Acta Sci. Pol., Architectura%V 5
%N 2
%P 5
%D 2006
%U https://www.architectura.actapol.net/volume5/issue2/_2_2006.pdf
%Z 1644-0692
%K mass diffusivity, desorption, non-stationary measurements
%X The paper provides a comparative analysis of three methods used to determine Dm diffusivity, which were tested for non-stationary desorption process and referred to various stages of its course. These are: the √t-type method – linked to the initial phase; the logarithmic procedure – for the advanced phase of the process, and the half-time method – referring to the point of time when 50% of mass has been exchanges. The article presents results of desorption process research carried out in the temperature of 20°C and encompassed three mortars characterized by the following water-cement ratios w/c = 0.50, 0.65 and 0.80. Samples of these mortars were conditioned for several months under air relative humidity φ= 97% until the time of reaching moisture equilibrium, and then they were placed in humidity conditions of φ≈ 0%. The values Dm(√t), Dm(ln), Dm(t0.5), obtained through the analyzed desorption process (T = 20°C, φ= 97% → 0%), presented a good conformity of all the three tested methods in the case of all the mortars – from the fully identical results: Dm(t0,5)/Dm(ln) = 1.00 with w/c = 0.80 to the most diversied ones: Dm(t0,5)/Dm(√t) = 1.23 with w/c = 0.65.