Assessment of the Density Loss in Anobiid Infested Pine Using X-ray Micro-Computed Tomography

Abstract

The present study aims at evaluating the impact of anobiid damage on pine timber elements. Anobiid attack produces a diffuse damage of the elements with a set of tunnels in random directions and sizes, thus confusing quantification. Therefore, a method was developed based on X-ray micro-computed tomography (μ-XCT) to obtain, for naturally infested timber samples, an empirical correlation between lost material percentage (consumed by beetles) and timber apparent density (original, before degradation—OTD and residual, after degradation—RTD). The quantified density loss can then be used in further assessment of the structure. The results of the tests performed showed high correlation between original apparent density and lost material percentage (r2 = 0.60) and between residual apparent density and lost material percentage (r2 = 0.83), which confirms μ-XCT as a valuable tool to the required quantification. The loss of density results can be further applied on the definition of an assessment method for the evaluation of the residual strength of anobiids infested timber, thus contributing to reducing unnecessary replacement. The optimized procedure of the μ-XCT study for infested Maritime pine (Pinus pinaster) is presented and discussed in this article.

X‐Ray Techniques Dedicated to Materials Characterization in Cultural Heritage

“…[107] Data acquisition is a timeconsuming and complicated task, which contributes to increasing the scan time, reconstruction time, and data size (highresolution images). [105] The XCT method is superior to the XRR method because it reveals specific and subtle details. [108] The XCT machine is a fixed, heavy, and expensive instrumentation that emits high-level radiation and requires high-technical expertise.…”

“…The relative attenuation of X‐rays is dependent on the thickness, density, and chemical composition of the material [104] . The two‐dimensional images (projections) can be visualized as cross‐sectional slices in three planes (axial, coronal, and sagittal), [105] which describe the cumulative attenuation of the X‐ray beam through the object [106] . A computed‐reconstruction algorithm is applied to create a stack of the slices, producing a three‐dimensional image (tomogram) and mapping the spatial distribution of the internal structures of the objects [107] .…”

“…A computed‐reconstruction algorithm is applied to create a stack of the slices, producing a three‐dimensional image (tomogram) and mapping the spatial distribution of the internal structures of the objects [107] . Data acquisition is a time‐consuming and complicated task, which contributes to increasing the scan time, reconstruction time, and data size (high‐resolution images) [105] . The XCT method is superior to the XRR method because it reveals specific and subtle details [108] .…”

Assessment of termite damage in cross-laminated timber sections using micro-computed tomography and vibration analysis

“…The scan data can be further processed to object volume, cross-sectional area, density, and porosity (Brock et al 2022). µ-CT has been used to study potential termite activities in wooden art frames and wood-boring beetles in maritime pine boards (Arbat et al 2021;Parracha et al 2021). The studies showed µ-CT's capabilities as a non-invasive method of identifying damage and providing a timeframe for planned maintenance of items (França et al 2019).…”

Comparison Between Experimental Results and Design Equations of Artificially Degraded Single Step Joints

“…However, the diffuse attack of this insect makes the assessment of damage intensity more difficult [2]. In fact, despite being the most recurrent, this evaluation method presents too many uncertainties, since the number of internal galleries drilled by the insects is greater than the surface exit holes, which can lead to an underestimation of the level of degradation [3,4]. Regarding the reduction of the mechanical capacity caused by the anobiid infestation, in general, it is considered in the structural verification of old structural elements either by the reduction of the cross-section of the element (considering that the degraded zone does not present any strength) or assuming reduced mechanical properties for that element [5,6].…”