Micro-Fabric, Pore-Size Distribution and Water Absorption of Consolidated Porous Limestone

Abstract

Miocene porous limestone from Soskut (Hungary) is one of the most common building stone in Hungarian monuments. This porous limestone has wide variety in fabric, porosity and pore-size distribution. These properties also influence the behaviour of limestones and control their durability against environmental hazards. Our study shows that pore structure has a primary role in weathering susceptibility, and it also influences the compatibility with different consolidants and the efficiency of consolidation. Fine-, medium- and coarse-grained porous limestones were tested under laboratory conditions. Cylindrical samples were consolidated by immersion under atmospheric pressure until full saturation was reached. In the tests three consolidants were applied: one type of silicic acid ester, an aliphatic urethane resin and Paraloid B72. Physical parameters such as density, ultrasonic pulse velocity, total porosity, pore-size distribution by mercury intrusion porosimetry and water absorption were measured on natural and consolidated samples. Our analyses have shown that the tested consolidants have different penetration depth which depends on fabric and pore-structure of limestone types.