Infrastructures

13 pages, 240 KiB

Open AccessReview

Strategies to Foster Competition for the Market in the Urban Bus Sector in Developing Countries

by Gabriel Stumpf Duarte de Carvalho and Rui Cunha Marques

Infrastructures 2020, 5(12), 115; https://doi.org/10.3390/infrastructures5120115 - 17 Dec 2020

Cited by 4 | Viewed by 2139

Different mechanisms have been adopted by developed and developing countries over the last decades to provide urban bus services. Although competitive tendering has been considered the standard method to procure urban bus services, it cannot be treated as a ready-made solution. Contracts are [...] Read more.

Different mechanisms have been adopted by developed and developing countries over the last decades to provide urban bus services. Although competitive tendering has been considered the standard method to procure urban bus services, it cannot be treated as a ready-made solution. Contracts are incomplete by nature and, after the tender, to avoid ex-post opportunism they must be properly monitored. Additionally, developing countries, in general, have weak regulatory bodies and limited capacity to oversee public contracts. This paper aims to review the literature to gather actions that can increase the competition in public tenders and improve service quality during the life of the contract in developing countries. Full article

13 pages, 1986 KiB

Open AccessArticle

Design Corrections in Spanish Office Buildings to Improve Energy Efficiency in the Face of Climate Change

by José A. Orosa, Diego Vergara, Feliciano Fraguela and Pablo Fernández-Arias

Infrastructures 2020, 5(12), 114; https://doi.org/10.3390/infrastructures5120114 - 13 Dec 2020

Viewed by 2209

Abstract

The majority of buildings in Europe are at present naturally ventilated and do not use heating or cooling equipment throughout the summer. However, this idea is changing and as a result heating ventilation air conditioning (HVAC) related energy consumption has been rising in [...] Read more.

The majority of buildings in Europe are at present naturally ventilated and do not use heating or cooling equipment throughout the summer. However, this idea is changing and as a result heating ventilation air conditioning (HVAC) related energy consumption has been rising in the recent years. On the other hand, predictions published by the intergovernmental Panel on Climate Change (IPCC) indicate an annual warming rate ranging between 0.1 and 0.4 °C. In the present study, the ISO 13790:2011 standard has been employed to analyze the effect of building design corrections over the energy saving of a real building during its mean life and under climatic change predictions. In this sense, the effect of climate change, ventilation rate and its energetic and carbon dioxide emissions implications are obtained for the next 15 years. The results obtained indicate that an increment in the air changes by natural ventilation will be more effective than changing the wall structure and, in consequence, the thermal inertia. In particular, it was obtained that an increase of natural ventilation will always reduce the energy consumption and that this consumption will be lower with time due to an increment of an average outdoor air temperature. This modification will allow reduced cooling energy peak demands during the summer season and improve indoor ambiences in mild regions and the energy efficiency. Full article

► Show Figures

Graphical abstract

20 pages, 8118 KiB

Open AccessArticle

Modelling the Complex Relationship between Interventions, Interventions Costs and the Service Provided When Evaluating Intervention Programs on Railway Infrastructure Networks

by Marcel Burkhalter and Bryan T. Adey

Infrastructures 2020, 5(12), 113; https://doi.org/10.3390/infrastructures5120113 - 10 Dec 2020

Cited by 7 | Viewed by 2586

Abstract

Determining the interventions, e.g., maintenance, renewal, improvement and extension, to be included in an infrastructure program requires the consideration of the asset, intervention, traffic, and network characteristics. This, in turn, requires the development of an appropriate system model enabling the construction of straightforward [...] Read more.

Determining the interventions, e.g., maintenance, renewal, improvement and extension, to be included in an infrastructure program requires the consideration of the asset, intervention, traffic, and network characteristics. This, in turn, requires the development of an appropriate system model enabling the construction of straightforward optimisation models. Although there are already a considerable number of such system models in the literature, improved modelling of the complex relationships between interventions, intervention costs and the service provided by the infrastructure network is possible—especially in the trade-off between the accuracy of considering the complex relationships and the simplicity of the mathematical formulation. This paper explains how to build system models for railway infrastructure networks that capture the complex relationships in a system model that can then be used to construct mixed integer linear optimisation models. The proposed type of system model includes how both intervention costs and impacts on service vary as a function of the type, time and location of the interventions included in intervention programs. The system models of this type consist of a graph that is used to model the relationship between the interventions and intervention costs on the asset level, and the relationship between the interventions and the service provided on the network level. The algorithm uses systematic intervention classification and a hierarchical network state structure to build the system model. For illustration purposes, a system model for a railway network consisting of five track segments, seven switches, a bridge, a tunnel and the power supply system is developed using the algorithm. Full article

(This article belongs to the Section Infrastructures Inspection and Maintenance)

► Show Figures

Graphical abstract

13 pages, 1392 KiB

Open AccessArticle

Maturity Improvements in Flood Protection Asset Management across the North Sea Region

by Berry Gersonius, Bart Vonk, Richard M. Ashley, Frank den Heijer, Wouter Jan Klerk, Natasa Manojlovic, Jeroen Rijke, Paul Sayers and Assela Pathirana

Infrastructures 2020, 5(12), 112; https://doi.org/10.3390/infrastructures5120112 - 10 Dec 2020

Cited by 6 | Viewed by 2609

Abstract

North Sea Region countries depend heavily on flood protection infrastructure, such as dikes, dams, sluices and flood gates. Knowledge on where, when and how much to invest to ensure functioning is of crucial importance for asset owners and operators. This requires asset management [...] Read more.

North Sea Region countries depend heavily on flood protection infrastructure, such as dikes, dams, sluices and flood gates. Knowledge on where, when and how much to invest to ensure functioning is of crucial importance for asset owners and operators. This requires asset management approaches that are adaptable, respond to feedback and function within various contexts. The FAIR (Flood defense infrastructure Asset management & Investment in Renovation, adaptation, optimisation and maintenance) project has developed a unique framework to ensure that asset management processes are adaptive, comprehensive and make effective connections across strategic, tactical and operational contexts. The framework has for the first time informed an assessment of maturity of five flood protection asset management organisations in the North Sea Region, using a seven-factor maturity assessment model. This paper describes the self-assessment process and the self-reported maturity changes during the project. Maturity assessments were undertaken on two occasions, at the start of the project, and again toward the end. This has revealed how the baseline level of maturity for each organisation developed over the course of the three-year project. The observed maturity changes indicate that adopting the FAIR framework has added value in improving current approaches to asset management. Full article

(This article belongs to the Special Issue Water Infrastructure Asset Management)

► Show Figures

Figure 1

15 pages, 4353 KiB

Open AccessArticle

Hourly Capacity of a Two Crossing Runway Airport

by Paola Di Mascio and Laura Moretti

Infrastructures 2020, 5(12), 111; https://doi.org/10.3390/infrastructures5120111 - 4 Dec 2020

Cited by 4 | Viewed by 2978

Abstract

At the international level, the interest in airport capacity is growing in the last years because its maximization ensures the best performances of the infrastructure. However, infrastructure, procedure, human factor constraints should be considered to ensure a safe and regular flow to the [...] Read more.

At the international level, the interest in airport capacity is growing in the last years because its maximization ensures the best performances of the infrastructure. However, infrastructure, procedure, human factor constraints should be considered to ensure a safe and regular flow to the flights. This paper analyzed the airport capacity of an airport with two crossing runways. The fast time simulation allowed modeling the baseline scenario (current traffic volume and composition) and six operative scenarios; for each scenario, the traffic was increased until double the current volume. The obtained results in terms of average delay and throughput were analyzed to identify the best performing and operative layout and the most suitable to manage increasing hourly movements within the threshold delay of 10 min. The obtained results refer to the specific examined layout, and all input data were provided by the airport management body: the results are reliable, and the pursued approach could be implemented to different airports. Full article

► Show Figures

Graphical abstract

23 pages, 9662 KiB

Open AccessArticle

Ecological Restoration Plasters and Mineral Pigments Designed with Raw Material from the Island of Gavdos

by Afroditi Fotiou, Claire Oiry, Kali Kapetanaki, Vassilis Perdikatsis, Nikolaos Kallithrakas-Kontos and Pagona-Noni Maravelaki

Infrastructures 2020, 5(12), 110; https://doi.org/10.3390/infrastructures5120110 - 3 Dec 2020

Cited by 1 | Viewed by 2940

Abstract

Gavdos is an island of ca. 34 km² located to the south of Crete, Greece, with a local landscape rich in clay material of remarkable diversity in colour and quality. The limited natural and human-made resources are persistently recycled, forming the built [...] Read more.

Gavdos is an island of ca. 34 km² located to the south of Crete, Greece, with a local landscape rich in clay material of remarkable diversity in colour and quality. The limited natural and human-made resources are persistently recycled, forming the built structures of the island and determining the island’s sustainable local tradition. In the framework of this research, areas with clay soil were identified through a geological survey and testimonies of local inhabitants. The studied clay samples were characterized with mineralogical and physicochemical analyses. Two out of ten samples with a clay content higher than 50%, after low-temperature thermal treatment (600 °C and 700 °C), functioned as pozzolanic additives enhancing the performance in resistance to salt decay and plasticity of lime mortars. Seven raw clay samples were used as pigments in lime-based colours and their performance and durability, as assessed with the appropriate laboratory analyses, revealed the existence of stable mineral pigments under UV and visible light irradiation. There is great potential in the exploitation of local raw material from the island of Gavdos for the restoration of the traditional building stock on the island in terms of resource efficiency, environmental impact and preservation of the local identity. Full article

(This article belongs to the Special Issue Selected Papers from the REHABEND 2020 Congress)

► Show Figures

Graphical abstract

16 pages, 2293 KiB

Open AccessArticle

Adaptive Asset Management for Flood Protection: The FAIR Framework in Action

by Bart Vonk, Wouter Jan Klerk, Peter Fröhle, Berry Gersonius, Frank den Heijer, Philipp Jordan, Ulf Radu Ciocan, Jeroen Rijke, Paul Sayers and Richard Ashley

Infrastructures 2020, 5(12), 109; https://doi.org/10.3390/infrastructures5120109 - 3 Dec 2020

Cited by 10 | Viewed by 4197

Abstract

Uncertainties about climate change consequences, changing societal requirements and system complexity require flood protection asset managers to continuously evaluate their asset management policies and practice to manage risk and improve the resilience of their assets. However, there are many challenges in doing this, [...] Read more.

Uncertainties about climate change consequences, changing societal requirements and system complexity require flood protection asset managers to continuously evaluate their asset management policies and practice to manage risk and improve the resilience of their assets. However, there are many challenges in doing this, with asset operators often facing conflicting interests and major uncertainties about the future needs for asset performance. In the EU Interreg IV FAIR project, flood protection asset owners and operators, with scientific partners from the North Sea Region of Europe collaborated to develop practical guidance for adaptive asset management of flood protection infrastructure. The central component of this guidance is the FAIR framework, presented here. The framework combines insights and principles from ISO 55000 on asset management and ISO 14090 on climate adaptation with asset operator experiences to provide a practical guide for integration of asset management considerations within both strategic and operational contexts via a tactical handshake. This is a means to avoid the common lack of connection between strategic plans and operational practice. The applicability of the framework is illustrated with examples from Pilot Cases within the FAIR project, in which its value in terms of improved asset management and reduced costs has been demonstrated. Full article

(This article belongs to the Special Issue Water Infrastructure Asset Management)

► Show Figures

Figure 1

12 pages, 4480 KiB

Open AccessArticle

The Strengthening of Masonry Walls in Seismic-Prone Areas with the CAM System: Experimental and Numerical Results

by Antonino Recupero and Nino Spinella

Infrastructures 2020, 5(12), 108; https://doi.org/10.3390/infrastructures5120108 - 3 Dec 2020

Cited by 3 | Viewed by 2661

Abstract

In this paper, experimental and numerical results of a research project about the structural behavior of strengthened masonry are presented and discussed. The aim of the research is to study the in-plane shear behavior of an old masonry wall with an opening in [...] Read more.

In this paper, experimental and numerical results of a research project about the structural behavior of strengthened masonry are presented and discussed. The aim of the research is to study the in-plane shear behavior of an old masonry wall with an opening in the arch form, reinforced with a pioneering system of 3D pre-tensioned stainless steel ties. The masonry wall was in-plane loaded until first cracking appeared, then it was reinforced and re-loaded until failure. The experimental results have highlighted the benefits of the reinforcing method adopted, especially to provide an increasing in terms of both strength and ductility. Numerical modeling of the masonry wall behavior was accomplished by using non-linear finite-element methods generally adopted for reinforced concrete elements. Full article

(This article belongs to the Special Issue Selected Papers from the REHABEND 2020 Congress)

► Show Figures

Figure 1

12 pages, 4098 KiB

Open AccessArticle

Smart Roads: An Overview of What Future Mobility Will Look Like

by Salvatore Trubia, Alessandro Severino, Salvatore Curto, Fabio Arena and Giovanni Pau

Infrastructures 2020, 5(12), 107; https://doi.org/10.3390/infrastructures5120107 - 1 Dec 2020

Cited by 57 | Viewed by 9414

Abstract

Transport engineering has recently undergone several significant changes and innovations, one of which is the appearance and spread of autonomous vehicles; with this technology becoming more common and ordinary by the day, it is now necessary to implement some systems and contexts to [...] Read more.

Transport engineering has recently undergone several significant changes and innovations, one of which is the appearance and spread of autonomous vehicles; with this technology becoming more common and ordinary by the day, it is now necessary to implement some systems and contexts to facilitate autonomous vehicle operations. Consequently, a different perspective is now arising when dealing with road infrastructures, aiming to simplify and improve efficiency and maintenance of the existing roads, increase the life cycle of newly built ones, and minimize the economic and financial impact at the same time. Roadway pavements are one of the primary factors affecting vehicle operations; over time, this distinctive aspect has gone through various mechanical and physical changes due to the adoption of new materials or design methods. Consequently, to the spread of autonomous vehicles, scientific research has begun to study and develop systems to make road pavements and platforms not exclusively aimed at bearing loads, but rather at considering them as a means of communication and information exchange, if not even as a source of energy. This new approach introduces the so-called “Smart Roads,” i.e., road infrastructures capable of communicating with vehicles and self-monitoring fundamental perspectives concerning driverless vehicles and the roadway platform life cycle. This paper examines the characteristics of Smart Roads, considering their broad field of application and their potential advantages and drawbacks. This paper also pursues the objective of describing the global vision, the possible future direction of these innovations concerning the automotive and transport industries, and a particular focus on infrastructures and roadways. Full article

(This article belongs to the Special Issue Resilient and Smart Transport Infrastructure for Connected and Autonomous Vehicles)

► Show Figures

Figure 1

14 pages, 7753 KiB

Open AccessArticle

Investigation Strategy for Structural Assessment of Historic Towers

by Antonella Saisi and Carmelo Gentile

Infrastructures 2020, 5(12), 106; https://doi.org/10.3390/infrastructures5120106 - 1 Dec 2020

Cited by 9 | Viewed by 2895

Abstract

Historical masonry towers are relevant architectural heritage often in a strategic position within city centres. Their height and position require specific controls in order to define the state of preservation. The paper describes the investigation procedures developed by the authors in selected case [...] Read more.

Historical masonry towers are relevant architectural heritage often in a strategic position within city centres. Their height and position require specific controls in order to define the state of preservation. The paper describes the investigation procedures developed by the authors in selected case studies. According to the timing and to the complexity of the structure, the approach requires preliminary visual inspections, geometric, crack pattern survey supplemented by historical research and stratigraphic survey. Operational modal testing evaluates the overall structural behaviour, indicating eventual local (or global) problems to study in depth by monitoring or further local tests. Emergency operations, such as controls after earthquakes, could require prompt procedures. In this case, the combination of visual inspection, geometric and damage survey with dynamic testing is a reliable procedure for structural assessment. Additional investigation increases the knowledge of local problems or gives information for further activity such as structural modelling. For instance, relevant data are the evaluation of the masonry quality or the control of the local state of stress to estimate through non-destructive or minor destructive testing in selected positions. Nevertheless, such activities require accurate projects of the investigation too, planning and localising several tests in order to solve the problems detected in the preliminary steps of the diagnosis process. Full article

(This article belongs to the Special Issue Selected Papers from the REHABEND 2020 Congress)

► Show Figures

Figure 1

11 pages, 2169 KiB

Open AccessArticle

Seismic Resistant Bridge Columns with NiTi Shape Memory Alloy and Ultra-High-Performance Concrete

by Hadi Aryan

Infrastructures 2020, 5(12), 105; https://doi.org/10.3390/infrastructures5120105 - 30 Nov 2020

Cited by 9 | Viewed by 3185

Abstract

Reinforced concrete bridge columns often endure significant damages during earthquakes due to the inherent deficiencies of conventional materials. Superior properties of the new materials such as shape memory alloy (SMA) and ultra-high-performance concrete (UHPC), compared to the reinforcing steel and the normal concrete, [...] Read more.

Reinforced concrete bridge columns often endure significant damages during earthquakes due to the inherent deficiencies of conventional materials. Superior properties of the new materials such as shape memory alloy (SMA) and ultra-high-performance concrete (UHPC), compared to the reinforcing steel and the normal concrete, respectively, are needed to build a new generation of seismic resistant columns. Application of SMA or UHPC in columns has been separately studied, but this paper aims to combine the superelastic behavior of NiTi SMA and the high strength of UHPC, in order to produce a column design with minimum permanent deformation and high load tolerance subjected to strong ground motions. Additionally, the excellent corrosion resistance of NiTi SMA and the dense and impermeable microstructure of UHPC ensure the long-term durability of the proposed earthquake resistant column design. The seismic performance of four columns, defined as steel reinforced concrete (S-C), SMA reinforced concrete (SMA-C), SMA reinforced UHPC (SMA-UHPC), and reduced SMA reinforced UHPC (R-SMA-UHPC) is analyzed through a loading protocol with up to 4% drift cycles. The use of NiTi SMA bars for the SMA reinforced columns is limited to the plastic hinge region where permanent deformations happen. All the columns have 2.0% reinforcement ratio, except the R-SMA-UHPC column that has a 1.33% reinforcement ratio to optimize the use of SMA bars. Unlike the S-C column that showed up to 68% residual deformation compared to peak displacement during the last loading cycle the SMA reinforced columns did not experience permanent deformation. The SMA-C and R-SMA-UHPC columns showed similar strengths to the S-C column, but with about 5.0- and 6.5-times larger ductility, respectively. The SMA-UHPC column showed 30% higher strength and 7.5 times larger ductility compared to the S-C column. Full article

► Show Figures

Figure 1

Journal Menu

Journal Browser

Infrastructures, Volume 5, Issue 12 (December 2020) – 11 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI