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Non-destructive techniques such as the contact sponge method (CSM) and the Karsten tube have been developed to assess the water absorption properties of building materials during field measurements. In contrast, laboratory investigations typically rely on capillary rise tests (CR) on centimetric specimens imposing a one-dimensional water flow. Although the results obtained from these methods are qualitatively comparable, a robust quantitative correlation is still lacking. An analytical expression has previously been proposed to estimate the sorptivity from measurements with non-destructive techniques, based on the assumption that the water penetration depth equals the lateral spreading of water on the material surface. In this study, we investigate the water absorption processes induced by the contact sponge method, by combining neutron radiography, which allows direct visualization of water penetration, with conventional capillary rise tests based on gravimetric measurements. Sandstones and limestones with porosities ranging from 10
This integrative review critically examines portable dynamic low-impact surface hardness (LISH) testing, also known as Leeb hardness. Since its adaptation for mineral materials in 1993, LISH has been increasingly adopted across geoscience, engineering, and heritage conservation as a portable, minimally invasive alternative or complementary method to traditional methods, such as the Schmidt Hammer. Despite this increased use, methodological knowledge remains fragmented across disciplines, with operational limitations and data interpretation challenges frequently under-reported. To address this, the review combined a semi-systematic literature review (n = 181 publications) with a cross-and interdisciplinary user survey (n = 50) to identify key strengths, including utility, versatility, and suitability for weathering and conservation assessments, while critically addressing challenges related to surface heterogeneity and porosity, as well as calibration and standardisation, thereby providing a novel integrative framework that captures both published evidence and practitioner-derived insights. Furthermore, this review identifies opportunities to extend the use of LISH to heterogeneous and layered materials, surface–biological interactions, and more systematic integration within existing monitoring frameworks. The review encourages transparent reporting of protocols, integration within multi-analytical frameworks, and the development of standardised procedures to enhance cross-study comparability and support informed adoption across research and practice.
Our study reveals multiple signals of Palaeolithic occupation in the Flemish Valley, a large depression in coastal northwestern Europe with an extremely sparse Pleistocene archaeological record until now. We show that mechanical coring can reveal archaeological evidence of hominin presence from deep palaeolandscapes that are inaccessible for standard survey techniques. At nine out of 41 coring sites, we encountered a total number of 56 lithic artefacts at depths up to 8 m below the surface. We conclude that this unexpected success rate indicates a widespread archaeological record. We believe that this survey method has the potential to increase the number of Palaeolithic sites in northwestern Europe by an order of magnitude, leading to a very different image of Pleistocene hominin settlement in this vast European lowland.
