Pore Structure and Water Transfer in Pietra d’Aspra Limestone: A Neutronographic Study

Abstract

Neutron radiography (NR) was here applied to study the effects of two different commercially available consolidants on the water absorption properties in a particular type of limestone (biocalcarenite), known as Pietra d’Aspra stone, which is one of the most extensively used lithotypes in Sicilian Baroque buildings. Our attention was mainly focused on the evaluation, using a fast and nondestructive visualization of water motion through capillarity, of the effectiveness of such layers as consolidating agents in view of preserving and maintaining both old and modern structures. The biocalcarenite was treated with nanosilica (Nano Estel®) and nanolime (CaLoSil®) by brushing it until full saturation, and then artificially weathered by salt crystallization and temperature/relative humidity jumps. Liquid distribution and height of the water front were monitored as a function of time. Significant differences in the water suction behavior among all the investigated samples were highlighted, which allowed us to gain insight into the coating/substrate interaction mechanisms which regulate the fluid mobility inside the porous network of the limestone.

Geopolymer Composite Coatings Based on Moroccan Clay and Sands for Restoration Application

“…For the other substrates, no changes were detected. This fact can be explained by the higher sensitivity of limestone to humidity weakening the bond between the substrate and the coating (Ciantia et al, 2014;Randazzo et al, 2020). Similar results were obtained for outside condition storage with a higher decrease of the adhesive strength in the case of limestone (about 3 and 4 MPa for the three coatings on white and blue limestones, respectively).…”

How Science Can Contribute to the Remedial Conservation of Cultural Heritage

“…The artifacts are typically analyzed to study degradation processes or gain anthropological, historical and artistic information. [4] Current challenges involve the development of newer non-invasive techniques [5] with high spatial resolution, [6] and portable instruments to allow feasible analysis of precious works. [7] Analytical tools can gain great support from modeling and theoretical chemistry, which can be employed to construct mechanisms for the degradative reactivity of art materials.…”

New Chemical Systems for the Removal of Calcareous Encrustations on Monumental Fountains: A Case Study of the Nymphaeum of Cerriglio

“…This chemical balance is affected by temperature, pressure, and other factors and can be easily found in nature (it is responsible for the formation of stalactites, encrustations, etc.) [5]. The abiotic formation of carbonates consists of four key factors: (i) an increase in the calcium concentration, (ii) the presence of high inorganic carbon concentration, (iii) the "alkalinity engine", which is activated with an increase in the water/seawater pH values, and (iv) the availability of nucleation sites [6,7].…”