Determination of the distribution of consolidants and interpretation of mercury porosimetry data in a sandstone porous network using LSCM

Abstract

Knowing the 3D distribution of a consolidant within the porous network of a rock is essential for understanding the porosity quantitative data obtained by mercury porosimetry and for observing the effect of consolidants on pore interconnection. In this work, we show for the first time that the distribution of consolidant in the porous network can be determined using laser scanner confocal microscopy (LSCM). Results indicate that consolidants are concentrated in pore throats of less than 40 microm in diameter, affecting both the porous interconnection and the circulation of fluids. LSCM allowed demonstration of the fact that the increase in microporosity detected by mercury porosimetry is due to the development of fissures within the consolidants. No consolidant that produces this kind of fissure can be used in the consolidation of building stones, since it would increase microporosity and, in consequence, vulnerability to weathering agents.

The building stone of the Roman city of Dougga (Tunisia): Provenance, petrophysical characterisation and durability

“…A mineralogy almost exclusively made of calcite, in turn, is the main reason for the very low resistance to abrasion observed in the studied samples (Table SM3). Several authors demonstrated the relationship between material characteristics such as degree of cementation, grain size distribution (Zoghlami and Gó mez-Gras, 2004), rock fabric (Siegesmund, 1996), and porosity, on the one hand, and the mechanical properties of the material, on the other hand. Ruedrich and Siegesmund (2007) demonstrated that porosity controls the mechanical and elastic properties of the rock.…”

Petrophysical behaviour and durability of the Miocene sandstones used in the architectural heritage of Tunisia (Roman aqueduct of Oued Miliane and Uthina Roman site)

“…As mercury porosimetry only measures pore access, real pore size was measured using LSCM (Zoghlami et al, 2004b). The results…”