Introduction of a new testing method (horizontal sorption) for the in-situ analysis of water absorption by porous stone surfaces and effect of surface treatments

Abstract

The aim of this paper is to introduce the horizontal sorption technique and to demonstrate its applicability for the observation of porous materials and effect of surface treatments. The horizontal sorption testing method is a new technique, which was developed to facilitate the in-situ assessment of water absorption properties of porous materials. This new technique has some advantages compared to the already existing in-situ testing methods (Karsten pipe method, contact sponge method). It is easy to use, requires no supplementary electric devices, and tight attachment of the measuring tool onto the surface is not necessary. Moreover, the absorption of the water can be easily initiated and then documented. In the present paper several different ways of application of the technique are shown. The testing method was proven to be appropriate for the evaluation of the rate of water absorption, for determination of the sedimentary fabric of the rock (layers and orientation of the fabric results from its formation), as well as the effective depth and nature of three different types of surface treatments. These treatments were (i) organic and inorganic molecules activating bacteria in the stone, (ii) a conventional stone consolidant and (iii) a biomineralizing protective treatment. The new testing method provided valuable information about the nature of all the three treatments. Therefore the horizontal sorption method (HSM) seems to be a highly promising tool for the analysis of porous materials.