In this paper a system is presented to monitor in-situ the curing process of sprayed concrete. This system consists of an instrumented trough based on wireless sensor networks for monitoring temperature/relative humidity and ultrasounds. The trough has been designed using a trapezoidal cast with several encapsulated transducers and an electronic system for generation, acquisition and processing of ultrasonic signals. A methodology for the measurement of ultrasonic velocity has also been proposed. This system has been proven to be a very good solution for in-situ monitoring of the curing process of sprayed concrete, being able to detect problems or defects in the material fabrication. ; This work was supported by Ministerio de Economía y Competitividad of Spain in the Call Retos- Colaboración 2015 [RTC-2015-3185-4 (MAPMIT)] and in the Call Retos Investigación [BIA2016-77992-R (AEI/FEDER, UE)]. Both projects were co-funded by the European Union through FEDER funds under the objective of promoting the technological development, innovation and high quality research. ; Peer Reviewed ; Postprint (author's final draft)
10 páginas; 12 figuras ; GPR is a non-destructive technique that consists in the emission of high frequency electromagnetic waves through a medium. Different electromagnetic properties and discontinuities within the medium produce reflections that allow to characterize its internal structure. In particular, pulses of radar energy are generated from a dipole transmitting antenna, placed on, or near, the surface of the medium under investigation: from soil layering, to masonry wall, up to frescoes (Leucci 2019; Masini et al. 2007; Masini et al. 2017) Focusing on architectural heritage applications, the measure of the time elapsed between transmission, reflection off a discontinuity and reception back at a surface radar antenna along with suitable data processing procedures, allow to identify and locate reflectors that, suitably post processed and visualized in 3D, enable to provide important information on the masonry, such as presence of cracks and fractures, the internal composition, the connection characteristics between stone blocks (Leucci et al. .2011) Such approach has been applied for the characterization of the columns of the Convento do Carmo church, in Lisbon. Figure 1 shows the used GPR apparatus and its general block diagram. The interface module enables the user to enter the system parameters and displays and records the data. The control unit generates the timing signals so that all the components operate in unison. This unit also does some preliminary data processing. The pulse travel paths in order of arrival are direct air wave, direct ground wave, and reflections. ; This publication shows the results of the Heritage Within (HWITHIN) European Research Project (Project Reference: 614719-CREA-1- 2019-1-PT-CROSS-SECT-INNOVLAB), co-funded by the Creative Europe Programme of the European Union, under the Cross-sectorial subprogramme, Bridging culture and audiovisual content through digital action.
11 páginas; 12 figuras ; The Heritage Within (HWITHIN) European Research Project aimed to develop an innovative approach to present buildings and archaeological ruins. The project proposed to implement state-of-the-art technologies to produce an innovative visualization of the cultural heritage by showing what is hidden to our naked eye and the unknown, nonvisible features of our buildings and archaeological assets. The final 3D model has been implemented into a virtual reality tour platform with augmented reality content to offer a unique visualization of the ruins of the church of the old Convent of Carmo, the project case study, on-site and remotely. The HWITHIN research project has been a great opportunity to explore how the integration of several tools can help to obtain a better understanding of our heritage and, at the same time, provide the public with specific technical content that is not commonly accessible. The project aims to make the public more aware of the essential role of professionals in the field of conservation (from art historians and archaeologists to engineers and architects), showing the importance of surveying, diagnostic and analysis activities for the preservation of our built heritage. This pilot experience can hopefully open new paths of investigation and be replicated and extended in other sites in the future. ; This publication shows the results of the Heritage Within (HWITHIN) European Research Project (Project Reference: 614719-CREA-1- 2019-1-PT-CROSS-SECT-INNOVLAB), co-funded by the Creative Europe Programme of the European Union, under the Cross-sectorial subprogramme, Bridging culture and audiovisual content through digital action.
11 páginas; 8 figuras ; The main objective of the Heritage Within (HWITHIN) research project is to investigate what is hidden to our naked eye. One of the core actions of the project was to explore the use of Ground Penetrating Radar (GPR) and ultrasonic acoustic tomography to document and reconstruct precisely the interior of the constructive elements, almost on a stone-by-stone basis. However, precisely because it is not visible, the results obtained and the conclusions drawn cannot be verified with the reality. In the case of the Carmo Convent, the structural elements under investigations are the neogothic compound piers of the main nave, reconstructed after the 1755 earthquake. There is insufficient information on the layout of the interior morphology of the pillar's cross-section. Additionally, finding relatable examples to compare to the compound pillars at the Carmo Convent are quite minimal, making it complicated for even initial assumptions to be established. Therefore, the team decided to construct 1:1 stone replicas of parts of the neogothic stone masonry pillars (the shaft and the pedestal). The specimens were used to assess the feasibility and efficiency of the non-destructive tests applied (GPR and acoustic tomography) to determine the layout of their internal morphology. Since the cross- section of the real pillars of the Carmo Convent is unknown, the replica only precisely depicts the exterior layout of the columns. The shapes of the stones were established on initial guesses based on literature review. Once the limestones were cut, several cross-sectional set-ups were prepared, mainly accounting for a wide range of possible interior core materials (from fully empty core to a solid limestone block filling). Acoustic tomography was carried out for each assembly so that accurate comparisons between the tomographic maps could be made. Moreover, given the known inner composition of the laboratory specimens, the results can help to understand the potential of the tomographic techniques by comparing the results with the expected visible interior. The present chapter shows some of the results obtained during the laboratory investigations, which were essential to interpret the ultrasonic tomography performed on-site at the old convent. The results confirm the potential of acoustic tomography techniques to convey an accurate idea of the cross-sectional elements within the pillar. The tomographic maps may not provide enough precision to determine exact dimensions of the materials and elements within the cross-section, but they can be complemented with GPR investigations and is always useful in a qualitative way, as it can provide information about the structural integrity of the materials and their arrangement. ; This publication shows the results of the Heritage Within (HWITHIN) European Research Project (Project Reference: 614719-CREA-1- 2019-1-PT-CROSS-SECT-INNOVLAB), co-funded by the Creative Europe Programme of the European Union, under the Cross-sectorial subprogramme, Bridging culture and audiovisual content through digital action.
