Fibrous plaster (FP) is a fabric-reinforced composite (FRC) comprising plaster of Paris (POP) and woven jute fabric (‘hessian’), historically used in decorative ceilings across the UK since the late 19th century. Despite its architectural significance, FP remains under-researched, limiting the development of reliable structural assessment methods. Recent ceiling failures have been linked to the tensile failure of the supporting component known as the ‘wad’. Acoustic emission (AE) provides a non-destructive means of remotely sensing and locating such failures from the underside of ceilings, yet its potential for extracting detailed information on FP wad failure processes remains unexplored. This study comprises two parts. First, an AE-based failure classification model was developed using unsupervised spherical k-means clustering to distinguish matrix cracking and fabric-matrix debonding based on the RA-AF method. Second, the first in-situ direct tensile tests on FP wad-analogue specimens conducted under synchrotron X-ray imaging were conducted at the I12 beamline of Diamond Light Source (DLS), UK, integrating AE monitoring with digital image correlation (DIC) and synchrotron X-ray computed tomography (sCT). This multi-modal dataset enabled examination of the AE model and internal failure analysis through digital volume correlation (DVC), while complementary crack analysis and the Kabsch algorithm provided new insight into the failure mechanisms of FP wads and revealed the reinforcement-bridging role of the hessian during progressive fracture. By linking remote AE monitoring with multi-scale observations, this study advances understanding of FP failure processes, offering a pathway for assessing historic ceilings and informing the design of more resilient FP components. • A non-destructive acoustic emission (AE) model classifies matrix cracking and fabric-matrix debonding in fibrous plaster (FP), using spherical k-means clustering on RA-AF features. • FP wad tests at the I12 beamline of Diamond Light Source integrate AE, digital image correlation (DIC), and synchrotron X-ray computed tomography (sCT). • The unique combination of digital image and volume correlation (DIC, DVC) provides complementary surface and volumetric measurements of failures. • Data reveal FP failure mechanisms in detail and clarify the reinforcement bridging role of hessian during progressive fracture. • Linking AE monitoring with multi-scale imaging advances understanding of FP damage, supporting an AE monitoring framework for assessing historic ceilings and informing the design of more resilient wad elements.
Zuo et al. (Sun,) studied this question.