Infrastructures

16 pages, 3324 KiB

Open AccessArticle

Mechanical Properties of Pervious Recycled Aggregate Concrete Reinforced with Sackcloth Fibers (SF)

by Arissaman Sangthongtong, Noppawan Semvimol, Thitima Rungratanaubon, Kittichai Duangmal and Panuwat Joyklad

Infrastructures 2023, 8(2), 38; https://doi.org/10.3390/infrastructures8020038 - 18 Feb 2023

Cited by 7 | Viewed by 1414

Abstract

The excessive production of construction waste is a significant concern as it requires proper disposal and may become economically unfeasible. Reusing construction waste in producing new concrete can substantially reduce the disposal requirements of construction waste. In addition, this results in a sustainable [...] Read more.

The excessive production of construction waste is a significant concern as it requires proper disposal and may become economically unfeasible. Reusing construction waste in producing new concrete can substantially reduce the disposal requirements of construction waste. In addition, this results in a sustainable solution for the rapidly depleting natural resources of concrete. Pervious concrete may contain up to 80% coarse aggregates and could be an exceptional host for reusing construction waste. This study aimed to investigate the mechanical properties of pervious concrete constructed with natural and recycled aggregates. The substandard properties of recycled aggregates were improved by adding natural fibers from sackcloth. This study presents an experimental program on 45 samples of pervious concrete with air void ratios and the size of coarse aggregates as the parameters of interest. The compressive strength of the pervious concrete decreased by increasing the air void ratio regardless of the size of the aggregates. The type of aggregates did not influence the permeability of pervious concrete, and the maximum temperature in pervious concrete increased as the quantity of air void ratios increased. The decrease in compressive strength was 40–60% as the void ratio was increased from 10–30% for all types of concrete mixes, such as natural and recycled aggregates. The permeability of small-size aggregates with 10% designed air void ratios for natural and recycled aggregates with sackcloth was 0.705 cm/s. Full article

(This article belongs to the Special Issue Innovative Solutions for Concrete Applications)

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25 pages, 13854 KiB

Open AccessArticle

Operational Modal Analysis of Historical Buildings and Finite Element Model Updating Using α Laser Scanning Vibrometer

by Costas P. Providakis, Maria G. Mousteraki and Georgia C. Providaki

Infrastructures 2023, 8(2), 37; https://doi.org/10.3390/infrastructures8020037 - 18 Feb 2023

Cited by 2 | Viewed by 1952

Abstract

Without affecting the integrity or stability of the heritage monuments, vibration-based techniques provide useful solutions for acquiring global information about them. By studying the dynamic response to suitable excitation sources, it is feasible to define the mechanical characteristics of structures and identify and [...] Read more.

Without affecting the integrity or stability of the heritage monuments, vibration-based techniques provide useful solutions for acquiring global information about them. By studying the dynamic response to suitable excitation sources, it is feasible to define the mechanical characteristics of structures and identify and locate defects in their global behaviour. Laser Doppler vibrometry (LDV), which enables non-contact measurements of the vibration velocity of moving surfaces using a focused laser beam, is a highly desirable technique for qualitative dynamic characterisation and damage assessment. LDV is a simple and non-intrusive approach. It permits remote measurements and has a high degree of sensitivity and frequency adaptation. In addition, the system is entirely computer controlled, providing simple data storage, processing, and analysis. LDV has been originally researched and developed for structural and modal shape analysis of physical prototypes, in-service devices (e.g., machinery components), medical imaging applications, and damage detection and analysis relevant to small-scale non-destructive testing (NDT), and evaluation of micro to meso-targets (e.g., fracture detection and mapping in composites, modal shape and vibration analysis of objects, etc.). In spite of several successful applications in the case of bridges and thin structures, ambient vibration testing in an integrated form that includes dynamic identification, sensitivity analysis, and numerical modelling update employing modern sensor non-contact technologies is still uncommon. In this paper, the authors intend to explore further the possibility of combining ambient vibrations and OMA in combination with the non-contact LDV sensing technique in order to remotely acquire mechanical waves travelling in historical structures, track the actual behaviour of such structures, and calibrate their finite element numerical models. Full article

(This article belongs to the Special Issue Advances in Structural Dynamics and Earthquake Engineering)

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23 pages, 3026 KiB

Open AccessArticle

Stochastic Multiphasic Multivariate State-Based Degradation and Maintenance Meta-Models for RC Structures Subject to Chloride Ingress

by Boutros El Hajj, Bruno Castanier, Franck Schoefs and Emilio Bastidas-Arteaga

Infrastructures 2023, 8(2), 36; https://doi.org/10.3390/infrastructures8020036 - 16 Feb 2023

Cited by 3 | Viewed by 1389

Abstract

The objective of this paper is to propose tools for the lifecycle management of infrastructure by showing the slow degradation processes for which inspection data are accessible, especially the data obtained from non-destructive testing (NDT) and structural health monitoring (SHM). One major characteristic [...] Read more.

The objective of this paper is to propose tools for the lifecycle management of infrastructure by showing the slow degradation processes for which inspection data are accessible, especially the data obtained from non-destructive testing (NDT) and structural health monitoring (SHM). One major characteristic of these degradation processes is their multiphasic nature; consequently, they can be discretised into different phases with specific physical kinematics where specific maintenance actions and measurement techniques can be performed. Within this framework, we propose implementing a degradation meta-modelling approach fed with measurements (NDT, SHM). This approach is based on state-dependent stochastic processes for modelling the degradation and maintenance of reinforced concrete structures that are subjected to chloride-induced deterioration. The benefit of using multiphasic degradation meta-models in the lifecycle management of infrastructure is illustrated through numerical examples that include single and multi-action management policies. Full article

(This article belongs to the Special Issue Critical Infrastructure Resilience Facing Extreme Weather Events)

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23 pages, 5242 KiB

Open AccessArticle

Incorporating the Benefits of Geosynthetic into MEPDG

by Murad Abu-Farsakh, Mehdi Zadehmohamad and George Z. Voyiadjis

Infrastructures 2023, 8(2), 35; https://doi.org/10.3390/infrastructures8020035 - 16 Feb 2023

Cited by 3 | Viewed by 1744

Abstract

One of the most effective ways to increase the longevity of pavement structures is through the integration of geosynthetic reinforcement. Geosynthetics are synthetic materials such as geotextiles, geogrids, or geocomposites that are added to the interface between the subgrade and the base layer [...] Read more.

One of the most effective ways to increase the longevity of pavement structures is through the integration of geosynthetic reinforcement. Geosynthetics are synthetic materials such as geotextiles, geogrids, or geocomposites that are added to the interface between the subgrade and the base layer of a pavement structure. To evaluate the effect of various parameters on the structural benefits of geosynthetic reinforcement on the pavement structure of low-volume traffic flexible pavements, a finite element (FE) study was performed using the ABAQUS program. These parameters included the geosynthetic type, geosynthetic tensile stiffness, subgrade stiffness, and base thickness. The FE rutting curves for the 100 cycles were calibrated using the mechanistic–empirical (M-E) transfer functions, which were then used to calculate the long-term rutting curves. The traffic benefit ratio (TBR) was initially calculated based on the calibrated rutting curves for each pavement layer. The calculated TBRs were then used as an input in AASHTOWare to compute the base effective resilient modulus (M_R-eff) and the factor of base course reduction (BCR). The results showed that adding one layer of geosynthetics enhanced the rutting performance of pavement structures significantly (up to 8.9 in TBR, 322% in M_R-eff, and 64% in BCR). Geogrids showed higher benefits than geotextiles due to the interlocking between base aggregates and geogrid aperture. The values of TBR, M_R-eff, and BCR increase with the increasing tensile stiffness of the geosynthetics and the rutting target and with the decreasing subgrade stiffness. The results also demonstrated peak values of TBR, M_R-eff, and BCR for a base thickness of 25.4 cm. Full article

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16 pages, 266 KiB

Open AccessArticle

A Background to a Methodology for Transport Mobile Applications Designing with a Focus on EU Interoperability

by Pavla Šmídová and Stanislav Machalík

Infrastructures 2023, 8(2), 34; https://doi.org/10.3390/infrastructures8020034 - 15 Feb 2023

Cited by 2 | Viewed by 1360

Abstract

European rail transport policy aims to create a single railway area. European Union (EU) issues, for this purpose, sets of regulations and directives. Individual countries are involved in its implementation according to their capabilities. The aim of this article is to examine the [...] Read more.

European rail transport policy aims to create a single railway area. European Union (EU) issues, for this purpose, sets of regulations and directives. Individual countries are involved in its implementation according to their capabilities. The aim of this article is to examine the current state of interoperability in the EU, especially in the Czech Republic, and to compare selected mobile applications regarding the possibility of unifying their design of mobile applications. A systematic literature research review methodology was used. The sources of information were mainly the scientific database Web of Science and the database of EU documents EUR-Lex. When examining one of the main parameters—the use of mobile networks—it was found that all of the selected applications use public mobile networks, none of them uses the Global System for Mobile Communications–Railway (GSM–R) network. This finding confirmed the theoretical assumption that this network is not currently ready for more or less massive operation of mobile applications. The possibility of using the next generation railway mobile network is open for discussion as one of the next steps to ensure interoperability in telematics applications. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

26 pages, 36720 KiB

Open AccessArticle

Investigation of “Open” Superstructure Tramway Tracks in Budapest

by Vivien Jóvér, Zoltán Major, Attila Németh, Dmytro Kurhan, Mykola Sysyn and Szabolcs Fischer

Infrastructures 2023, 8(2), 33; https://doi.org/10.3390/infrastructures8020033 - 15 Feb 2023

Cited by 5 | Viewed by 1492

Abstract

The most important thing nowadays is to use available resources to develop infrastructure as efficiently as possible. In this regard, evaluating the deterioration of tramway tracks is critical from both a technical and an economic viewpoint. In Hungary, seven types of superstructure systems [...] Read more.

The most important thing nowadays is to use available resources to develop infrastructure as efficiently as possible. In this regard, evaluating the deterioration of tramway tracks is critical from both a technical and an economic viewpoint. In Hungary, seven types of superstructure systems are currently differentiated in the case of tramway transport, but the geometrical deterioration, lifecycle, and lifecycle cost of the tramway tracks are not accurately known. The current study aimed to evaluate and compare the results of track geometry measurements of two different “open” tramway superstructure systems depending on their traffic load and age. The geometry measurements we re executed by TrackScan 4.01 instrument, developed and maintained by a Hungarian developer company called Metalelektro Méréstechnika Ltd. The evaluation of the measurements showed a clear relationship between the traffic load, age, and track deterioration. Based on the results, it can be generally stated, concerning “open” superstructure systems, that regardless of the “open” superstructure system or the level of traffic load, the average value of alignment is decreasing; however, the average value of the longitudinal level is increasing. Furthermore, the deterioration of an older ballasted track with lower traffic is similar to that of a younger ballasted track that has a higher traffic load. Another significant result was that the deterioration of the track gauge parameter in the case of concrete slab tracks is clearly described as the broadening of the track gauge. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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14 pages, 3291 KiB

Open AccessArticle

Testing of Lubricants for DIC Tests to Measure the Forming Limit Diagrams of Aluminum Thin Sheet Materials

by Szabolcs Szalai, Hanna Csótár, Dmytro Kurhan, Attila Németh, Mykola Sysyn and Szabolcs Fischer

Infrastructures 2023, 8(2), 32; https://doi.org/10.3390/infrastructures8020032 - 14 Feb 2023

Cited by 5 | Viewed by 1425

Abstract

We investigated lubricants and thin teflon foils that can be applied in the formability testing of the thin aluminum sheets used in the electronics and automotive industries. For the tests, thirteen different industrial lubricants (oils and greases) (i.e., L1–L13) and two Teflon films [...] Read more.

We investigated lubricants and thin teflon foils that can be applied in the formability testing of the thin aluminum sheets used in the electronics and automotive industries. For the tests, thirteen different industrial lubricants (oils and greases) (i.e., L1–L13) and two Teflon films (i.e., 0.08 and 0.22 mm thick) were applied. The authors conducted an Erichsen test, and the thickness reduction of the discs was measured first. In forming-limit curve (FLC) tests, it is crucial that the stresses are localized in the central area of the specimen during forming and that biaxial deformation is maintained throughout, if possible. We aimed to achieve and fulfill this task. To perform this measurement, the GOM ARAMIS measuring system was utilized. It is an optical measuring system based on the digital image correlation (DIC) principle, capable of measuring both stresses and displacements in real time. A specific validation method was also developed to qualify the DIC system. We concluded that there was a 5% difference in Erichsen indentation (IE) number diagrams between the best (L12) and worst (L4) cases for the lubricants and oils tested, which is a significant difference for thin plates. We found that this value could be increased and improved by using Teflon discs. Furthermore, the localization of stress maxima, i.e., the centering of cracks in the specimen, could be achieved by combining Teflon discs and L12 lubricant (with appropriate layer order), which significantly aids in the recording of standard FLC diagrams. Using foils is also advantageous because they are readily available, have no expiry date, and are of less environmental concern. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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15 pages, 14595 KiB

Open AccessArticle

Vibration Diagnostic Methods of Automatic Transmission Service Requirement Prediction

by Péter Őri, Szabolcs Kocsis Szürke, Dmytro Kurhan, Mykola Sysyn, István Lakatos and Szabolcs Fischer

Infrastructures 2023, 8(2), 31; https://doi.org/10.3390/infrastructures8020031 - 10 Feb 2023

Cited by 2 | Viewed by 1966

Abstract

Automatic transmission is a key factor for autonomous driving. The transmission condition is highly affected by the quality and quantity of transmission oil in the system. However, the oil condition is not monitored in the system, and the oil change interval and method [...] Read more.

Automatic transmission is a key factor for autonomous driving. The transmission condition is highly affected by the quality and quantity of transmission oil in the system. However, the oil condition is not monitored in the system, and the oil change interval and method are still a subject of discussion. This paper analyzes the effects of oil changes in automatic transmissions. The measurements were carried out before and after the oil change with the same external conditions. With the vibration measurement method, data can be collected without disassembling the parts and during operational conditions. Furthermore, time- and frequency-based analyses were conducted to compare different transmissions’ operations. The results have shown that the effect of oil degradation is measurable on the amplitude of the signals and, therefore, predictable with vibration diagnostics. During the evaluation, the maximum values were compared on measurements with at least a 2-s length. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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21 pages, 6551 KiB

Open AccessArticle

Optimizing Road Safety Inspections on Rural Roads

by Giuseppe Cantisani, Chiara Caterina Borrelli, Giulia Del Serrone and Paolo Peluso

Infrastructures 2023, 8(2), 30; https://doi.org/10.3390/infrastructures8020030 - 08 Feb 2023

Cited by 6 | Viewed by 1943

Abstract

Road safety depends on a complex balance between all the factors that compose the road system: user, vehicle, environment, and infrastructure. Directive 2008/96/EC introduces procedures to improve the European Transport Network (TEN-T) safety, recognizing an important role for safety inspections, but focusing them [...] Read more.

Road safety depends on a complex balance between all the factors that compose the road system: user, vehicle, environment, and infrastructure. Directive 2008/96/EC introduces procedures to improve the European Transport Network (TEN-T) safety, recognizing an important role for safety inspections, but focusing them on freeways and highways. This paper proposed methods and criteria useful to optimize current inspection procedures and adapt them also to secondary and local rural roads. It is often complex to determine the severity and weight of the different risk factors in this context, since deficiencies and faults can be found both in the road infrastructure and in the other components of the system. The proposed survey method was applied to a stretch of the SS7 Appia state road (Lazio, Italy). Producing video capture and using GPS sensors to geolocalize the data proved to be very useful for the compilation of the survey forms. The results showed a good consistency between the safety assessments obtained from the scoring of the inspection forms and the historical accident rate. Therefore, the proposed methodology can be a valuable aid in understanding safety concerns and in defining the improvement actions. Full article

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13 pages, 2787 KiB

Open AccessArticle

Predictive Stress Modeling of Resilient Modulus in Sandy Subgrade Soils

by Tadas Tamošiūnas and Šarūnas Skuodis

Infrastructures 2023, 8(2), 29; https://doi.org/10.3390/infrastructures8020029 - 08 Feb 2023

Cited by 2 | Viewed by 1360

Abstract

The mechanical properties of pavement materials are crucial to the design and performance of flexible pavements. One of the most commonly used measures of these properties is the resilient modulus (E_r). Many different models were developed to predict the resilient modulus [...] Read more.

The mechanical properties of pavement materials are crucial to the design and performance of flexible pavements. One of the most commonly used measures of these properties is the resilient modulus (E_r). Many different models were developed to predict the resilient modulus of coarse soils, which are based on the states of stresses and the physical and mechanical properties of the soil. The unconsolidated unsaturated drained cyclic triaxial tests were performed for three variously graded and three well-graded sand specimens to determine the resilient modulus, and to perform predictive modeling using the K-θ, Rahim and George, Uzan, and Universal Witczak models. Obtained E_r values directly depended on the confining pressure and deviatoric stress values used during the test. The Octahedral Shear Stress (OSS) model, proposed by the authors of the paper, predicts the resilient modulus with a coefficient of determination (R²) ranging from 0.85 to 0.99. The advantage of the model is the use of small-scale data tables, meaning fixed K₁ and K₂ regression coefficients, and it can be assigned to a specific specimen type without the need to determine them using the specific deviatoric and confining stresses. Full article

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26 pages, 5808 KiB

Open AccessArticle

Optimization of Surface Preparation and Painting Processes for Railway and Automotive Steel Sheets

by Szabolcs Szalai, Brigitta Fruzsina Szívós, Dmytro Kurhan, Attila Németh, Mykola Sysyn and Szabolcs Fischer

Infrastructures 2023, 8(2), 28; https://doi.org/10.3390/infrastructures8020028 - 08 Feb 2023

Cited by 11 | Viewed by 1966

Abstract

The article deals with DIC (Digital Image Correlation) tests on steel plates used in the automotive and railway industries, as well as in the construction industry. The most critical part of DIC tests is the quality of proper surface preparation, painting, and random [...] Read more.

The article deals with DIC (Digital Image Correlation) tests on steel plates used in the automotive and railway industries, as well as in the construction industry. The most critical part of DIC tests is the quality of proper surface preparation, painting, and random patterns. The paint mediates the deformation of the optical systems, and its quality is paramount. The authors’ goal in this research is to determine the optimal dye–cleaning–drying time parameters for DIC studies. Commercially available surface preparation and cleaning agents were tested alongside commercially available spray paints. Standard and specific qualification procedures were applied for the measurements. Once the appropriate parameters were determined, the results were validated and qualified by GOM ARAMIS tests. Based on the results, DIC measurements can be performed with higher accuracy and safety in laboratorial and industrial conditions, compared to the traditional deformation measurements executed by dial gauges or linear variable differential transformers. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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18 pages, 6923 KiB

Open AccessArticle

Optimization of Surface Cleaning and Painting Methods for DIC Measurements on Automotive and Railway Aluminum Materials

by Szabolcs Szalai, Viktória Fehér, Dmytro Kurhan, Attila Németh, Mykola Sysyn and Szabolcs Fischer

Infrastructures 2023, 8(2), 27; https://doi.org/10.3390/infrastructures8020027 - 06 Feb 2023

Cited by 9 | Viewed by 1863

Abstract

The preparatory operations of DIC (Digital Image Correlation) tests were investigated in this study, with special emphasis on specimen cleaning and painting operations. As it is well known, DIC tests are non-contact and applied in materials research, the analysis of complex structures, and, [...] Read more.

The preparatory operations of DIC (Digital Image Correlation) tests were investigated in this study, with special emphasis on specimen cleaning and painting operations. As it is well known, DIC tests are non-contact and applied in materials research, the analysis of complex structures, and, nowadays, the construction industry. The use of DIC technologies has seen a dynamic increase in all scientific fields. In our study, aluminum body panels for automotive and railway applications were tested using this technique. There are many articles on proper patterning in the literature but fewer on preparation and priming. These are critical for a successful DIC measurement. This paper looks at different surface cleaners and primers with different grading procedures and will also determine the time window within which the paint should be applied. Finally, the GOM ARAMIS system was applied to measure and characterize the painted surface and visible deformation defects resulting from inadequate painting. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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21 pages, 5688 KiB

Open AccessArticle

Investigation of Track Gauge and Alignment Parameters of Ballasted Railway Tracks Based on Real Measurements Using Signal Processing Techniques

by Szabolcs Fischer, Nándor Liegner, Péter Bocz, Ákos Vinkó and György Terdik

Infrastructures 2023, 8(2), 26; https://doi.org/10.3390/infrastructures8020026 - 06 Feb 2023

Cited by 5 | Viewed by 1648

Abstract

This paper deals with the time-frequency characteristic analysis for track geometry irregularities using field data recorded by a comprehensive track inspection train. The parameters of the track gauge and the left and right rail alignment are considered to identify their characteristic wavelengths and [...] Read more.

This paper deals with the time-frequency characteristic analysis for track geometry irregularities using field data recorded by a comprehensive track inspection train. The parameters of the track gauge and the left and right rail alignment are considered to identify their characteristic wavelengths and the locations of their waveforms. In addition to the conventional time and frequency domain analysis, auto-adaptive signal decomposition techniques are used on four pre-selected track sections. During the time series analysis of the track gauge, the cumulative difference from the mean value is calculated, which makes it possible to distinguish the track section constructed with non-standard initial track gauges. The sensitive wavelengths of the track irregularities are obtained from the proper allocation of wavelength ranges in the Fourier Amplitude Spectrum of the original signal and the Fourier transform of the components detected by the Variational Mode Decomposition. This analysis can elucidate the wavelengths and positions of track irregularities that affect vehicle responses. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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14 pages, 4905 KiB

Open AccessTechnical Note

Methodologic Recommendations to Implement Pavement Management Systems and Eco-Sustainable Solutions for Local Road Administrations

by Andrea Grilli and Alex Balzi

Infrastructures 2023, 8(2), 25; https://doi.org/10.3390/infrastructures8020025 - 05 Feb 2023

Cited by 4 | Viewed by 2045

Abstract

Local Road Administrations (LRA) manage wide and fragmented road networks with constrained financial and human resources. Though LRA manage the most road networks and the relative development and maintenance have a huge impact on environment and society, frequently, LRA cannot implement new technologies [...] Read more.

Local Road Administrations (LRA) manage wide and fragmented road networks with constrained financial and human resources. Though LRA manage the most road networks and the relative development and maintenance have a huge impact on environment and society, frequently, LRA cannot implement new technologies and methodological advancements because innovations are generally fitted to different kinds of users. For these reasons, the adoption of a customised pavement management system (PMS) for LRA is strongly recommended to define workflows, make investments, and find long-lasting and cost-effective solutions. Considering the goal of a sustainable development, new complex aspects must be also considered in the PMS matching policies, investment strategies and engineered solutions. Eco-sustainable techniques for the maintenance of road pavements and utility trenches must be gradually introduced in PMS involving stakeholders to preserve natural resources, to reduce atmospheric pollutions and to stimulate the local economic growth. The definition of a PMS guideline for LRA considering new concepts of a circular economy is a contemporary and open challenge. This paper shows a new PMS approach for LRA, including the strategy and requirements for environmentally friendly road materials that can be progressively adopted by each LRA to lessen the negative effects of maintenance activities on the environment. Full article

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17 pages, 4105 KiB

Open AccessArticle

Operational Modal Analysis as a Support for the Development of Digital Twin Models of Bridges

by Vanni Nicoletti, Riccardo Martini, Sandro Carbonari and Fabrizio Gara

Infrastructures 2023, 8(2), 24; https://doi.org/10.3390/infrastructures8020024 - 05 Feb 2023

Cited by 21 | Viewed by 2539

Abstract

Many transportation infrastructures all around the world are facing new challenges in terms of ageing and loss of performance. The infrastructural asset managers are required to perform scrupulous control of the health condition of the infrastructures over time and to execute the required [...] Read more.

Many transportation infrastructures all around the world are facing new challenges in terms of ageing and loss of performance. The infrastructural asset managers are required to perform scrupulous control of the health condition of the infrastructures over time and to execute the required maintenance works. In this context, digital twin models of the infrastructures should have a key role to simplify and speed up the procedures for proper maintenance. This paper discusses the advantages of developing digital twin models for the management of infrastructures, with a focus on bridges. In particular, the role of dynamic tests performed on bridges for the development of digital twin models is addressed, paying attention to test procedures and requirements. Issues such as the quality of instrumentation, the numerosity, and layout of sensors, and the acquisition and post-processing procedures are addressed through applications to two real bridge case studies. Both infrastructures are multi-span pre-stressed RC bridges that were dynamically tested after the restoration and seismic upgrading works. Results of ambient vibration tests and operational modal analyses are described, providing an idea of dynamic test requirements, as well as their use within the framework of the digital twin model creation. Full article

(This article belongs to the Topic Development of Monitoring, Analysis and Maintenance Technics of Infrastructures)

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14 pages, 7674 KiB

Open AccessArticle

Examination of Concrete Canvas under Quasi-Realistic Loading by Computed Tomography

by Balázs Eller, Majid Movahedi Rad, Imre Fekete, Szabolcs Szalai, Dániel Harrach, Gusztáv Baranyai, Dmytro Kurhan, Mykola Sysyn and Szabolcs Fischer

Infrastructures 2023, 8(2), 23; https://doi.org/10.3390/infrastructures8020023 - 05 Feb 2023

Cited by 5 | Viewed by 1690

Abstract

The current paper concerns the investigation of CC (Concrete Canvas), a unique building material from the GCCM (geosynthetic cementitious composite mat) product group. The material is suitable for trench lining, trench paving, or even military construction activities, while the authors’ purpose is to [...] Read more.

The current paper concerns the investigation of CC (Concrete Canvas), a unique building material from the GCCM (geosynthetic cementitious composite mat) product group. The material is suitable for trench lining, trench paving, or even military construction activities, while the authors’ purpose is to investigate the application of the material to road and railway substructure improvement. This research was carried out to verify the material’s suitability for transport infrastructure and its beneficial effects. The authors’ previous study reported that the primary measurements were puncture, compression, and the parameters evaluated in four-point bending (laboratory) tests. However, based on the results, finite element modeling was not feasible because the testing of the composite material in a single layer did not provide an accurate indication. For this reason, the material characteristics required for modeling were investigated. A unique, novel testing procedure and assembly were performed, wherein the material was loaded under quasi-realistic conditions with a crushed stone ballast sample and other continuous particle size distribution samples in a closed polyethylene tube. In addition, the deformation of the material following deformed bonding was measured by computed tomography scanning, and the results were evaluated. Full article

(This article belongs to the Special Issue Land Transport, Vehicle and Railway Engineering)

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18 pages, 2895 KiB

Open AccessArticle

A Novel Framework on Security and Energy Enhancement Based on Internet of Medical Things for Healthcare 5.0

by Rajesh Natarajan, Gururaj Harinahallo Lokesh, Francesco Flammini, Anitha Premkumar, Vinoth Kumar Venkatesan and Shashi Kant Gupta

Infrastructures 2023, 8(2), 22; https://doi.org/10.3390/infrastructures8020022 - 02 Feb 2023

Cited by 18 | Viewed by 2665

Abstract

Background: The Internet of Medical Things, often known as IoMT, is a revolutionary method of connecting medical equipment and the software that operates on it to the computer networks that are used in healthcare 5.0. The rapid development of smart medical devices on [...] Read more.

Background: The Internet of Medical Things, often known as IoMT, is a revolutionary method of connecting medical equipment and the software that operates on it to the computer networks that are used in healthcare 5.0. The rapid development of smart medical devices on IoMT platforms has led to the adoption of major technologies in the modernization of healthcare procedures, the administration of diseases, and the improvement in patient treatment standards. The IoMT offers a variety of cloud-based applications, including data exchange, data screening, patient surveillance, information collection and analysis, and hygienic hospital attention. Wireless sensor networks (WSNs) are responsible for both the gathering and delivery of data. Method: The safety of patients and their right to privacy are the top priorities in the healthcare sector. Anyone may see and modify the patient’s health information because the data from these smart gadgets are sent wirelessly through the airways. Hence, we developed a unique elliptic curve cryptography-based energy-efficient routing protocol (ECC-EERP) to provide a high level of security and energy efficient system for healthcare 5.0. Data can be encrypted using the key-based method ECC-EERP. It employs pairs of public and private keys to decrypt and encrypts web traffic and reducse the amount of energy needed by a WSN in aggregate. Result and Discussion: The efficiency of the suggested method was evaluated in comparison with that of a variety of existing methods. The suggested method was evaluated with the use of many parameters such as security, encryption throughput, energy efficiency, network lifetime, communication overload, computation time, and implementation cost. The results showed that the proposed technique provides enhanced security and energy efficiency. Full article

(This article belongs to the Special Issue Data Infrastructures)

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13 pages, 2302 KiB

Open AccessArticle

Machine Learning Modelling for Compressive Strength Prediction of Superplasticizer-Based Concrete

by Seyed-Ali Sadegh-Zadeh, Arman Dastmard, Leili Montazeri Kafshgarkolaei, Sajad Movahedi, Saeed Shiry Ghidary, Amirreza Najafi and Mozafar Saadat

Infrastructures 2023, 8(2), 21; https://doi.org/10.3390/infrastructures8020021 - 02 Feb 2023

Cited by 3 | Viewed by 1532

Abstract

Superplasticizers (SPs), also known as naturally high-water reducers, are substances used to create high-strength concrete. Due to the system’s complexity, predicting concrete’s compressive strength can be difficult. In this study, a prediction model for the compressive strength with SP was developed to handle [...] Read more.

Superplasticizers (SPs), also known as naturally high-water reducers, are substances used to create high-strength concrete. Due to the system’s complexity, predicting concrete’s compressive strength can be difficult. In this study, a prediction model for the compressive strength with SP was developed to handle the high-dimensional complex non-linear relationship between the mixing design of SP and the compressive strength of concrete. After performing a statistical analysis of the dataset, a correlation analysis was performed and then 16 supervised machine learning regression techniques were used. Finally, by using the Extra Trees method and creating the SP variable values, it was shown that the compressive strength values of concrete increased with the addition of SP in the optimal dose. The results indicate that superplasticizers can often reduce the water content of concrete by 25 to 35 per cent and consequently resistivity increased by 50 to 75 per cent and the optimum amount of superplasticizers was up to 12 kg per cubic meter as well. From one point, the increase in superplasticizers does not lead to a rise in the concrete compressive strength, and it remains constant. According to the findings, SP additive has the most impact on concrete’s compressive strength after cement. Given the scant information now available on concrete-including superplasticizer, it is prudent to design a concrete mixing plan for future studies. It is also conceivable to investigate how concrete’s compressive strength is impacted by water reduction. Full article

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19 pages, 8766 KiB

Open AccessArticle

Deep Learning-Based Real-Time Traffic Sign Recognition System for Urban Environments

by Chang-il Kim, Jinuk Park, Yongju Park, Woojin Jung and Yong-seok Lim

Infrastructures 2023, 8(2), 20; https://doi.org/10.3390/infrastructures8020020 - 31 Jan 2023

Cited by 5 | Viewed by 5685

Abstract

A traffic sign recognition system is crucial for safely operating an autonomous driving car and efficiently managing road facilities. Recent studies on traffic sign recognition tasks show significant advances in terms of accuracy on several benchmarks. However, they lack performance evaluation in driving [...] Read more.

A traffic sign recognition system is crucial for safely operating an autonomous driving car and efficiently managing road facilities. Recent studies on traffic sign recognition tasks show significant advances in terms of accuracy on several benchmarks. However, they lack performance evaluation in driving cars in diverse road environments. In this study, we develop a traffic sign recognition framework for a vehicle to evaluate and compare deep learning-based object detection and tracking models for practical validation. We collect a large-scale highway image set using a camera-installed vehicle for training models, and evaluate the model inference during a test drive in terms of accuracy and processing time. In addition, we propose a novel categorization method for urban road scenes with possible scenarios. The experimental results show that the YOLOv5 detector and strongSORT tracking model result in better performance than other models in terms of accuracy and processing time. Furthermore, we provide an extensive discussion on possible obstacles in traffic sign recognition tasks to facilitate future research through numerous experiments for each road condition. Full article

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17 pages, 6429 KiB

Open AccessArticle

Development of an Engineered Slurry-Infiltrated Fibrous Concrete: Experimental and Modelling Approaches

by Mohammed H. Yas, Mohammed M. Kadhum and Watheq G. B. Al-Dhufairi

Infrastructures 2023, 8(2), 19; https://doi.org/10.3390/infrastructures8020019 - 31 Jan 2023

Cited by 3 | Viewed by 1640

Abstract

Concrete is the central pile for the infrastructure that maintains civilisation and human life. The concrete industry faces many challenges, including improving mechanical properties, eco-friendliness, and durability. In this context, the present study focuses on evaluating and modelling themechanical properties of engineered concrete, [...] Read more.

Concrete is the central pile for the infrastructure that maintains civilisation and human life. The concrete industry faces many challenges, including improving mechanical properties, eco-friendliness, and durability. In this context, the present study focuses on evaluating and modelling themechanical properties of engineered concrete, namely slurry-infiltrated fibrous concrete (SIFCON). The main experiments will be devoted to measuring and modelling the failures of slabs made from SIFCON under two loading systems, namely static and impact loading systems. The model was developed using a non-linear finite element analysis. The experiments considered the influence of the geometry of the reinforcement steel fibres (hook-end fibres, microfibres, and combined hook-end and microfibres), sizes of fibres, and slab dimensions. The outcomes of this investigation showed that increasing the slab’s thickness enhances the load-bearing capacity of the SIFCON slab, and the microfibres and combined hook-end and microfibres improved the load-bearing capacity of the slab compared to the hook-end fibre. Generally, it was noticed that the outcomes of the experiments agreed with the modelling outcomes. Nevertheless, it was noticed that experimentally measured axial deformation was more significant than the predicted axial deformation. In summary, the difference between experimental and modelling outcomes was 1.1–10.2%, with a standard deviation of 0.0264. Based on the excellent ability of SIFCON to resist impacts and dynamic loads, it is recommended to be used in pavements, military structures, nuclear reactor walls, and in areas subjected to high bending moments, such as corner connections subjected to opening bending moments. Full article

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23 pages, 23043 KiB

Open AccessArticle

Seismic Analysis of Historical Urban Walls: Application to the Volterra Case Study

by Giovanna Concu, Mariangela Deligia and Mauro Sassu

Infrastructures 2023, 8(2), 18; https://doi.org/10.3390/infrastructures8020018 - 30 Jan 2023

Cited by 1 | Viewed by 1602

Abstract

Several Italian cities are characterized by the presence of centuries-old historic walls, which have a cultural heritage value and, due to their structural role as a retaining wall, often influence the safety of adjacent buildings and infrastructure. Ancient urban walls are increasingly subject [...] Read more.

Several Italian cities are characterized by the presence of centuries-old historic walls, which have a cultural heritage value and, due to their structural role as a retaining wall, often influence the safety of adjacent buildings and infrastructure. Ancient urban walls are increasingly subject to instability and collapse phenomena, because the greater frequency of extreme meteoric events aggravates the static condition of the walls and of the wall–soil system. Since the seismic risk in the contexts in which the historical urban walls are located is often medium-high, it is advisable to evaluate the influence of soil moisture on the seismic response of the soil–structure system. In this paper, the seismic vulnerability of historical urban walls was examined through considering scenarios of both dry and wet soil, in order to evaluate the seismic response of the structure as a function of soil imbibition. Seismic vulnerability analyses were carried out on the case study of the historical urban masonry walls of Volterra (Italy), which have been affected by two major collapses in the last ten years. Seismic vulnerability was assessed by means of the limit equilibrium method and the finite element method, and through adopting proper soil imbibition models. The results highlight which sections of the walls are at greater seismic risk due to the presence of soil moisture, as well as the influence of soil imbibition on the structural safety and failure mechanism. Full article

(This article belongs to the Section Sustainable Infrastructures)

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13 pages, 1376 KiB

Open AccessArticle

Development of Mathematical Models for Trucks and Cargo

by Larisa Makhova, Mark Haykin, Irina Glazkova and Olga Domnina

Infrastructures 2023, 8(2), 17; https://doi.org/10.3390/infrastructures8020017 - 28 Jan 2023

Cited by 1 | Viewed by 1423

Abstract

International trade allows countries to expand their markets and access goods and services that otherwise may not have been domestically available. As a result of international trade, the market is more competitive. This ultimately results in more competitive pricing and brings a cheaper [...] Read more.

International trade allows countries to expand their markets and access goods and services that otherwise may not have been domestically available. As a result of international trade, the market is more competitive. This ultimately results in more competitive pricing and brings a cheaper product home to the consumer. The development of mathematical models to optimize the delivery of goods using a limited number of trucks is an urgent task for researchers around the world. The research goal was to use a developed mathematical model that allows one to optimize the performance of transportation tasks based on the selected parameters, both in terms of a particular truck and a fleet of trucks in the Russian region. The parameters (function, condition, cost, time, and quality) were set and an algorithm for the process of matching a specific truck and cargo was developed as part of the unit transportation task. A mathematical model has been developed for performing multiple freight tasks and operating a fleet of trucks, which considering such factors as cost, time, quality, and reputation, allows one to find an acceptable solution for a specific transportation task. A mathematical model was developed that considers such factors as cost, time, quality, and reputation, allowing one to find an acceptable solution for a particular transportation task. The simulation was performed in MATLAB 2018. The parameters of the simulations were a population size of 300, a maximum number of iterations of 2000, and a probability of selection of 0.85. From the 30 runs, the optional value was chosen as the best solution. The developed mathematical models have been tested for solving single and multiple transport problems under truck fleet simulation conditions. The results of the work can be used to optimize the operation of truck fleets in the Russian Federation and other countries. Full article

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19 pages, 625 KiB

Open AccessArticle

Patterns of Learning: A Systemic Analysis of Emergency Response Operations in the North Sea through the Lens of Resilience Engineering

by Riana Steen, Geir Haakonsen and Trygve Jakobsen Steiro

Infrastructures 2023, 8(2), 16; https://doi.org/10.3390/infrastructures8020016 - 21 Jan 2023

Cited by 7 | Viewed by 1990

Abstract

Crisis-induced learning (CIL), as a concept, has an ancient history. Although the academic literature offers a range of sophisticated approaches to address CIL, it is still not quite clear how we learn, how we know we have learned, and what challenges and opportunities [...] Read more.

Crisis-induced learning (CIL), as a concept, has an ancient history. Although the academic literature offers a range of sophisticated approaches to address CIL, it is still not quite clear how we learn, how we know we have learned, and what challenges and opportunities are involved in the CIL process. To address these questions and navigate ways forward, we need to use a specific real-world subject to capture contextual issues involved in a crisis cycle, which affects the learning process. In this paper, we uncover patterns of learning by exploring contextual issues involved with “actual scenarios” related to three COVID-19 episodes (emergencies) between August and December 2020. To analyze the study’s findings, we use three different themes from the DARWIN Generic Resilience Management Guidelines: (1) supporting the coordination and synchronization of emergency-response operation activities, (2) managing adaptive capacity, and (3) developing and revising procedures and checklists. Looking into these “real scenarios” seems fruitful for understanding patterns of learning, and it results in several learning recommendations. Among others, this study reveals how the uncertainty involved in emergency-response operations creates cognitive demands for emergent problem-solving. Full article

(This article belongs to the Special Issue Infrastructure Resilience in Emergency Situations)

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