Roberto Carneiro, Pedro Conceiçã and Artur Viana Fernandes
For countries and regions all over the world, the Digital Economy brings threats as well as opportunities, fast timeframes and narrow windows of opportunity. Nowhere are these…
Abstract
For countries and regions all over the world, the Digital Economy brings threats as well as opportunities, fast timeframes and narrow windows of opportunity. Nowhere are these factors more concentrated than in Macau, whose independence comes in the aftermath of regional economic turmoil and the accession of China to the WTO. Small in size and economically dependent on its mighty neighbours, Macau must diversify if it is to survive. The Digital Economy is its chance to recapture the role of intermediary between East and West. This study of the territory’s digital landscape and infrastructure yields an integrated set of policies and actions that could help create a sustainable digital cluster in Macau.
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Janaina Salustio, Sando Torres, António Azevedo, Fernando Artur Nogueira Silva and J.M.P.Q. Delgado
Prismatic specimens were fabricated, consisting of two ceramic tiles bonded by an intermediate adhesive mortar layer. To simulate pre-existing defects, an acetate film was…
Abstract
Purpose
Prismatic specimens were fabricated, consisting of two ceramic tiles bonded by an intermediate adhesive mortar layer. To simulate pre-existing defects, an acetate film was strategically inserted into one of the mortar-ceramic interfaces, creating controlled cracks of varying sizes. The specimens were subjected to low-amplitude cyclic loading, inducing simultaneous tensile and shear stresses within the system. The vibrational responses of the samples were recorded, and their frequency-domain amplitudes were analyzed.
Design/methodology/approach
Ceramic tile detachment remains a significant issue in contemporary construction, despite advancements in technology and updates to regulatory standards. The majority of these failures occur at the adhesive mortar-ceramic tile interface due to the combined effects of tensile and shear stresses. While this phenomenon is well-documented, experimental studies assessing the adhesion integrity of façade cladding systems are limited. This study aims to evaluate the adhesion performance of adhesive mortars using a non-destructive vibrational analysis technique.
Findings
The results enabled the characterization of the dynamic behavior of the specimens, identification of frequency regions corresponding to individual components, and formulation of diagnostic criteria for damage detection. Analysis of the resonance spectra also made it possible to identify a peak that can be related to the behavior of the mortar-substrate interface. Additionally, the elastic and dissipated energy metrics were calculated to quantify the system’s mechanical behavior. The study further investigated the impact of crack size, curing time and adhesive mortar type on the overall structural integrity.
Originality/value
This work aims to evaluate the adhesion performance of adhesive mortars using a non-destructive vibrational analysis technique. Resonance frequency measurements have also been used in research to analyze the propagation paths of cracks in metallic samples from aircraft engines. However, despite the widespread use of non-destructive techniques based on resonance frequencies for damage assessment, their application in the field of coating systems seems to be virtually unexplored. Therefore, this research attempts to address this gap by investigating the bond integrity of adhesive mortar joints, focusing on the analysis of the material’s resonance frequencies and their associated peak parameters.