Pore-structure and water transport properties of surfacetreated building stones

Abstract

This paper describes the details of a laboratory investigation aimed at ascertaining the effect of penetrating surface treatments on the micro-porosity and water transport properties of three building stones used in the construction of historic buildings and monuments within Europe. The pore-structure and morphology of treated and untreated stone specimens were assessed using a combination of helium autopycnometry, mercury intrusion porosimetry and scanning electron microscopy techniques. Water repeUence and transport properties were evaluated using the Karsten tube and magnetic resonance imaging techniques respectively.It was found that surface penetrating treatments have a pore-refining effect on the stone matrix, the extent of internal alteration being dependent on the initial porestructure. A treatment efficiency index has been established for evaluating the performance of treated surfaces.

The role of rock surface hardness and internal moisture in tafoni development in sandstone

“…By measuring the decrease in water level with the tube over a set period of time the water absorption per square centimetre can be calculated. In this study, the tube was attached to the horizontal rock face, usually on the floor of the tafoni, with Blue‐tack to seal any openings and then left for 90 minutes to ensure full absorption was reached (Nwaubani et al , ). Measurements were taken every 10 minutes for the duration of the 90 minute infiltration time.…”

Non-destructive testing of concrete treated with penetrating surface sealant using a Karsten-tube

“…The consequence of this is that recently, it has become mandatory in many countries for Highway concrete bridges. Other practical methods, for evaluation and assessment of the efficacy of treated concrete and stone surfaces has been suggested [14,15,16], but more needs to be done for this to be widely accepted. Thus, this paper presents the results of a study carried out on concrete surfaces, with and without penetrating sealers, using simple, and mostly non-destructive in-situ test methods to evaluate moisture absorption.…”

Pore Characterization of Volcanic Tuffs Used as Building Stone in Afyonkarahisar (Turkey)

“…Its applications have varied from the study of pore structure and fluid distributions by Pickell et al [32], studied by Klavetter and Peters [33] regarding hydrologic properties of volcanic tuff [34]. Many investigators have reported pore size and its distribution with using mercury intrusion of the rocks [34,35,36,37,38,39,40,41] they also describe general concepts of mercury porosimetry measurements and determination pore size distribution and its characterization. Vacchiano et al, [42] measured the pore-size distribution by mercury porosimetry of yellow and grey tuff stones of the historic buildings in Salerno (Italy).…”