Renan Rocha Ribeiro
@uminho.pt
Doctoral student at the Department of Civil Engineering
University of Minho
RESEARCH, TEACHING, or OTHER INTERESTS
Civil and Structural Engineering, Engineering
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Thomas Russo, Renan Rocha Ribeiro, Amir Araghi, Rodrigo de Melo Lameiras, José Granja, and Miguel Azenha
MDPI AG
The Elastic Modulus Measurement through Ambient Response Method (EMM-ARM) is designed to continuously monitor the elastic modulus of hardening construction materials such as concrete, cement paste, mortars, stabilized soils, and epoxy resin. In practice, a composite beam, made of the tested material in its mould, is induced to vibration by means of environmental or controlled excitation, and its resonant frequency is identified. The material’s elastic modulus can then be calculated based on the vibration equation of structural systems. The traditional system to conduct EMM-ARM experiments is based on specialized equipment and on proprietary licensed software, which results in a considerable cost, as well as limited options for customization. The paper hereby presented proposes a delve into the development and validation of a cost-effective and open-source system that is able to conduct EMM-ARM experiments. By using a Raspberry Pi for the computing device and cost-effective electronic components, the cost of the system was one-twentieth of the traditional one, without compromising the measurement reliability. The composite beam’s excitation is generated, while the vibration response is recorded by the proposed system simultaneously, since the Raspberry Pi supports multiprocessing programming techniques. The flexibility earned by the exclusive use of open-source and cost-effective resources creates countless application possibilities for the proposed system.
José Granja, Renan Rocha Ribeiro, Thomas Russo, Rodrigo Lameiras, and Miguel Azenha
Japan Concrete Institute
Renan Rocha Ribeiro, Rafael de Almeida Sobral, I. B. Cavalcante, Luís Augusto Conte Mendes Veloso and Rodrigo de Melo Lameiras
Structural health monitoring (SHM) has gained importance because many structures are approaching the end of their design life and demanding maintenance and monitoring. Low-cost solutions may push forward a widespread implementation of SHM on infrastructures but further investigation is still required to assess the performance of technically accessible, simple, and scalable low-cost systems. This work presents the development and validation of a low-cost vibration-based SHM multinode wireless system, based on the Arduino platform, for identification of modal parameters in civil infrastructures. Full details about the hardware and source code of the system are disclosed in an open repository, allowing its reproduction even by non-specialists in electronics. The sampling frequency stability of the system is experimentally characterized, and interpolation postprocessing algorithms are proposed to solve inherent limitations. The system is validated, and its performance is investigated in impulse and ambient vibration tests performed in a real-scale slab and a high-grade system. The data obtained from the proposed system in impulse tests allowed estimation of natural frequencies within 2%, and MAC values around 0.3 to 0.9, in relation to those estimated with the high-grade system. However, the low-cost system was unable to produce usable data in ambient vibration tests.
Mohamad El Sibaii, Renan Rocha Ribeiro, Ricardo Dias, José Rui Pinto, José Granja, and Miguel Azenha
Springer Nature Switzerland
Renan Rocha Ribeiro, Matheus Ian Castro Sousa, João Henrique da Silva Rêgo, and Rodrigo de Melo Lameiras
Springer Science and Business Media LLC
R. Rocha Ribeiro, L. A. C. M. Veloso, and R. M. Lameiras
Springer International Publishing
Renan Rocha Ribeiro, Elton Bauer, and Rodrigo Lameiras
MDPI AG
Low-cost electronics developed on easy-to-use prototyping platforms, such as Arduino, are becoming increasingly popular in various fields of science. This article presents an open-source and low-cost eight-channel data-logging system for temperature and humidity monitoring based on DHT22 (AM2302) sensors, named HIGROTERM. The system was designed to solve real needs of the Laboratory of Material Testing of the Department of Civil and Environmental Engineering at the University of Brasília. The system design, functionalities, hardware components, source code, bill of materials, assemblage and enclosure are thoroughly described to enable complete reproduction by the interested reader. The terminologies and instructions presented were simplified as much as possible to make it accessible to the greatest extent to researchers from different areas, especially those without electronics background. The data-acquisition system has an estimated total cost of USD 96.00, or USD 136.00 if eight sensor nodes are included, with a considerable margin for cost reduction. The authors expect that the HIGROTERM system may both be a valuable low-cost and customizable tool for the readers, as well a source of innovation and interest in low-cost electronics for real problem-solving in various fields of science.
John Kennedy Fonsêca Silva, Renan Rocha Ribeiro, and Rodrigo de Melo Lameiras
FapUNIFESP (SciELO)
abstract: Insulated pre-cast concrete wall panels, also called sandwich panels, consist in two external concrete layers, in which an internal layer of thermal insulation material is inserted between, aiming better acoustic and thermal performance. One of the main concerns regarding the performance of these panels refers to the elimination of thermal bridges caused by metallic connectors, which jeopardize the panels’ thermal efficiency. One of the proposals to solve this problem consists in the use of PERFOFRP connectors, which are plane plates with perforated holes through its thickness, which are embedded into the concrete plates, creating anchorage pins that enhance the shear strength and the layers’ debonding resistance. This research had the objective of evaluating the production quality of this type of connector, produced with a low-cost and easy-to-use vacuum assisted resin infusion system; considering the effects of: (a) resin plate homogeneity, by taking samples from various locations on the plate; (b) fabrication repeatability; and (c) raw production materials’ origin; on the results of: (I) ultimate tensile stress, (II) modulus of elasticity, and (III) volume fraction of fibre. Also, 18 specimens in the form of representative models of the shear connector in insulated pre-cast concrete wall panels, with six different hole configurations achieved by varying the holes’ diameter and spacing, were subjected to push-out tests, to assess the holes’ diameter and spacing effects on the mechanical performance of the connection in terms of ultimate load capacity and stiffness. The results indicated a production quality with a satisfactory level of characteristics variation, considering: the variability in different parts of a single composite plate, the variability between composite plates from different infusion process, and the variability between different production batches. Furthermore, the push-out tests demonstrated that the perforated connectors presented, when compared to non-perforated connectors: a gain in shear strength from 8% to 25%, lower relative displacements, and higher levels of stiffness. It was also observed that connectors with 25.40 mm diameter holes presented better performance than connectors with 31.75 mm diameter holes; and that the reducing the hole spacing from 2.00 to 1.75, for the 25.40 mm diameter specimens, caused a decrease in the load capacity of the connector. Thus, it was verified that variations on the hole’s diameter and spacing influenced the load carrying capacity of the connection.
Renan Rocha Ribeiro and Rodrigo de Melo Lameiras
FapUNIFESP (SciELO)
Sensing techniques based on accelerometers for modal parameters identification are among the most studied and applied in Structural Health Monitoring of civil structures. The advent of low-cost MEMS accelerometers and open-source electronic platforms, such as Arduino, have facilitated the design of low-cost systems suitable for modal identification, although there is still a lack of studies regarding practical application and comparison of commercially available low-cost accelerometers under SHM conditions. This work presents an experimental performance evaluation of six low-cost MEMS accelerometers for the identification of natural frequencies and damping ratios of a three-storey frame model and a reinforced concrete slab, as well as their noise characteristics. A low-cost Arduino-based data acquisition system was used. The results showed an overall good performance of the MEMS accelerometers, with identified natural frequencies errors within 1.02% and 7.76% of reference values, for the three-storey frame and concrete slab, respectively, and a noise density as low as 108 g/√Hz.
Renan Rocha Ribeiro, Fernando Gussão Bellon, Rita de Cássia Silva Sant’Ana Alvarenga, Ana Augusta Passos Rezende, José Maria Franco de Carvalho, and Rodrigo Felipe Santos
Trans Tech Publications, Ltd.
Aligned with the world’s tendency of searching for sustainable technologies, the waste addition into materials of the civil construction is an interesting option for wastes that do not have proper destination. This work has the objective of studying the feasibility of incorporating paint waste from furniture painting booth, which currently does not have any correct ecological destination, into covering mortars and investigate if this addition brings any improvement in performance. For this purpose, it was prepared six compositions of covering mortars, with a cement-sand volume proportion of 1:6 and a Flow-table consistency of 260 mm +- 10mm, varying the waste percentage added among the proportions of 0%, 2%, 4%, 6%, 8% and 10% on the cement weight. It was determined, for each composition, the specific gravity and the air-entrained content in the fresh stage. For physical tests, it was moulded nine prismatic samples and one mortar substrate for the bond tensile strength test per mortar composition. It was determined the flexural and compressive strength in the hardened stage, the specific gravity, the water absorption coefficient due to capillary action and the bond tensile strength. Leaching tests were performed for environmental analysis of the mortars produced with waste addition. It was observed that all the mortars with waste received a similar classification to the mortar without waste, according to NBR 13281 [], and the leaching tests showed that mortars with waste were not ecologically dangerous, demonstrating the feasibility of the incorporation. In addition, mortars produced with waste presented an increase in the entrained air percentage, which might be a beneficial action of the paint waste.