Marble decay: towards a measure of marble degradation based on ultrasonic wave velocities and thermal expansion data

Abstract

Marble as ornamental and dimensional stones as well as in their natural environments show complex weathering phenomena. Physical, chemical, and biological weathering of marble are well documented. The impact of climate change on monuments and historic buildings in terms of modeling and predicting future scenarios requires new approaches to forecast the ongoing decay in the near and far future. Ultrasonic wave velocities are a powerful and sensitive tool for the damage assessment of marble. For a maximum porosity of up to 1%, ultrasonic wave velocities (P-wave velocities) are ranging between 1 km/s and over 6 km/s. Water saturation has an important influence on the magnitude and directional dependence of ultrasonic wave velocities together with the mineralogical composition and the rock fabrics. Ongoing experimental alteration approaches were used to document the state of deterioration using Vp-systematics. In addition, thermal expansion and the residual strain values after applying thermal impacts were used to introduce a new quantitative measure based on experimental length changes and volume changes. To quantify such volume changes, a so-called decay index was proposed. Marbles are sensitive to weathering and have different volume changes under exposure depending on fabric parameters. The volume extension index of marble, based on thermal expansion measurements under dry and water-saturated conditions, is proposed as a decay index for quantifying sample stability and for defining the directions of maximum and minimal dilatation. Such decay index was implemented to different marble types and it was turned out that marbles with the larger decay indexes are more prone to weathering than with smaller ones. The effect of changing climate and, in consequence, different weathering actions can help to calculate or forecast risk numbers based on the Vp data in combination with the proposed decay index especially for marbles.

Thermal-Induced Microstructure Deterioration of Egyptian Granodiorite and Associated Physico-Mechanical Responses

“…Physical parameters such as porosity, mass loss, attenuation of ultrasonic waves, and the appearance measured following thermal treatments are beneficial indicators of the degree of deterioration generated in the rock specimens [ 50 ]. As a result, all samples’ original properties (weight, volume, P-wave, hue, etc.)…”

“…The greater heating rate degrades the rock's microstructure, modifying its physical, morphological, and mineralogical properties. Consequently, a low heating rate of 5 °C/min has been adopted to avoid any possible thermal shock within the specimens [50]. At four different target temperatures, 200, 400, 600, and 800 °C, thermic effects on granodiorite were studied.…”

Decay Detection in an Ancient Column with Combined Close-Range Photogrammetry (CRP) and Ultrasonic Tomography

“…The integrated use of different non-invasive techniques, such as CRP digital photogrammetry and 3D ultrasonic tomography, corroborated by the analysis of the petrographic characteristics of the investigated materials is of paramount importance in assessing the state of conservation of the shallow and deep zones of the marble making up the investigated structure. Knowledge of the stone material conditions and its decay processes, as well as the mechanisms governing them depend on the intrinsic properties of the investigated material, such as mineral composition, texture, nature, and distribution of porosity, as well as their interrelationship with the environmental exposure [50].…”

Numerical investigation on origin and evolution of polygonal cracks on rock surfaces

“…The effect of regional expansion and contraction has been investigated by many researchers (Jonhson, 1927;Rice, 1976;Smith, 1977;Williams and Robinson, 1989;Hall and André, 2003;Gómez-Heras et al, 2008;Riley et al, 2012;García-Rodríguez et al, 2015a). Siegesmund et al (2000Siegesmund et al ( , 2021 carried out the pioneering work on marble cracking caused by thermal expansion. Meanwhile, the thermal processes at environmental temperatures differ from those at higher temperatures because different temperature variations lead to diverse stress distributions due to mineral thermal expansion/contraction (Vázquez et al, 2015).…”