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Infrastructures, Volume 4, Issue 2 (June 2019) – 25 articles

Cover Story (view full-size image): Concrete with good bond and high shear strength as well as excellent flowability is necessary to fill bridge deck closure joints in accelerated bridge construction (ABC). We suggest that polymer concrete (PC) produced using poly methyl methacrylate and standard aggregate is an excellent alternative material for deck closure joints in ABC. Experimental test results of PC were compared to ultra-high-performance concrete (UHPC) and showed that PC has a development length of about 50% that required for UHPC. Furthermore, PC showed a shorter splice length than that necessary for UHPC and shear strength that is twice that of UHPC. It is evident that using PC in bridge deck closure joints in ABC can improve constructability, reduce joint size, eliminate reinforcing bar congestion, and provide considerable cost savings. View this paper.
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Article
Eco-Efficient Fiber-Reinforced Preplaced Recycled Aggregate Concrete under Impact Loading
Infrastructures 2019, 4(2), 37; https://doi.org/10.3390/infrastructures4020037 - 21 Jun 2019
Cited by 5 | Viewed by 3170
Abstract
This study explores highly eco-efficient preplaced aggregate concrete mixtures having superior tensile characteristics and impact resistance developed for pavement and infrastructure applications. A fully recycled granular skeleton consisting of recycled concrete aggregate and recycled tire rubber granules, and steel wire fibers from scrap [...] Read more.
This study explores highly eco-efficient preplaced aggregate concrete mixtures having superior tensile characteristics and impact resistance developed for pavement and infrastructure applications. A fully recycled granular skeleton consisting of recycled concrete aggregate and recycled tire rubber granules, and steel wire fibers from scrap tires are first placed in the formwork, then injected with a flowable grout. Considering its very high recycled content and limited mixing and placement energy (only the grout is mixed, and no mechanical vibration is needed), this material has exceptional sustainability features and offers superior time and cost savings. Moreover, typical problems of rapid loss of workability due to the high-water absorption of recycled aggregates and the floating of lightweight tire rubber granules are prevented since the aggregates are preplaced in the formwork. The much higher granular content and its denser skeleton reduce the cementitious dosage substantially and provide high volume stability against shrinkage and thermal strains. The behavior under impact loading of this sustainable preplaced recycled aggregate concrete, incorporating randomly dispersed steel wire fibers retrieved from scrap tires, was investigated using a drop weight impact test. The results show that recycled tire steel wire fibers significantly enhanced the tensile and impact properties. A two-parameter Weibull distribution provided an accurate prediction of the impact failure strength of the preplaced recycled aggregate concrete mixtures, allowing to avert additional costly laboratory experiments. Full article
(This article belongs to the Special Issue Durability and Sustainability of Concrete Mixtures)
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Review
Fiber Optics Sensors in Asphalt Pavement: State-of-the-Art Review
Infrastructures 2019, 4(2), 36; https://doi.org/10.3390/infrastructures4020036 - 20 Jun 2019
Cited by 11 | Viewed by 4178
Abstract
Pavement design is essentially and usually a structural long-term evaluation process which is needed to ensure that traffic loads are efficiently distributed at all levels of the total road structure. Furthermore, to get a complete analysis of its durability behavior, long-term monitoring should [...] Read more.
Pavement design is essentially and usually a structural long-term evaluation process which is needed to ensure that traffic loads are efficiently distributed at all levels of the total road structure. Furthermore, to get a complete analysis of its durability behavior, long-term monitoring should be facilitated, not only from the top by falling weight deflectometer (FWD) or core drilling but preferably from inside the structure and at exactly the same positions during a long-time interval. Considering that it is very hard to devise an efficient method to determine realistic in-situ mechanical properties of pavements, the determination of strain at the bottom of asphalt pavement layers through non-destructive tests is of a great interest. As it is known, fiber Bragg grating (FBG) sensors are the most promising candidates to effectively replace conventional strain gauges for a long-term monitoring application in a harsh environment. The main goals of this paper are to compile an overview of the recent developments worldwide in the application of fiber optics sensors (FOS) in asphalt pavement monitoring systems; to find out if those systems provide repeatable and suitable results for a long-term monitoring; if there are certain solutions to validate an inverse modelling approach based on the results of FWD and FOS. Full article
(This article belongs to the Special Issue Recent Advances and Future Trends in Pavement Engineering)
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Article
Urban Drainage Networks Rehabilitation Using Multi-Objective Model and Search Space Reduction Methodology
Infrastructures 2019, 4(2), 35; https://doi.org/10.3390/infrastructures4020035 - 08 Jun 2019
Cited by 4 | Viewed by 3283
Abstract
The drainage network always needs to adapt to environmental and climatic conditions to provide best quality services. Rehabilitation combining pipes substitution and storm tanks installation appears to be a good solution to overcome this problem. Unfortunately, the calculation time of such a rehabilitation [...] Read more.
The drainage network always needs to adapt to environmental and climatic conditions to provide best quality services. Rehabilitation combining pipes substitution and storm tanks installation appears to be a good solution to overcome this problem. Unfortunately, the calculation time of such a rehabilitation scenario is too elevated for single-objective and multi-objective optimization. In this study, a methodology composed by search space reduction methodology whose purpose is to decrease the number of decision variables of the problem to solve and a multi-objective optimization whose purpose is to optimize the rehabilitation process and represent Pareto fronts as the result of urban drainage networks optimization is proposed. A comparison between different model results for multi-objective optimization is made. To obtain these results, Storm Water Management Model (SWMM) is first connected to a Pseudo Genetic Algorithm (PGA) for the search space reduction and then to a Non-Dominated Sorting Genetic Algorithm II (NSGA-II) for multi-objective optimization. Pareto fronts are designed for investment costs instead of flood damage costs. The methodology is applied to a real network in the city of Medellin in Colombia. The results show that search space reduction methodology provides models with a considerably reduced number of decision variables. The multi-objective optimization shows that the models’ results used after the search space reduction obtain better outcomes than in the complete model in terms of calculation time and optimality of the solutions. Full article
(This article belongs to the Special Issue Water Infrastructure Asset Management)
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Article
Sensitivity of the Flow Number to Mix Factors of Hot-Mix Asphalt
Infrastructures 2019, 4(2), 34; https://doi.org/10.3390/infrastructures4020034 - 07 Jun 2019
Cited by 6 | Viewed by 3152
Abstract
In the design of pavement infrastructure, the flow number is used to determine the suitability of a hot-mix asphalt mixture (HMA) to resist permanent deformation when used in flexible pavement. This study investigates the sensitivity of the flow numbers to the mix factors [...] Read more.
In the design of pavement infrastructure, the flow number is used to determine the suitability of a hot-mix asphalt mixture (HMA) to resist permanent deformation when used in flexible pavement. This study investigates the sensitivity of the flow numbers to the mix factors of eleven categories of HMAs used in flexible pavements. A total of 105 specimens were studied for these eleven categories of HMAs. For each category of asphalt mixture, the variations in flow number for different contractors, binder types, effective binder contents, air voids, voids in mineral aggregates, voids filled with asphalt, and asphalt contents were assessed statistically. The results show that the flow numbers for different types of HMA used in Colorado vary from 47 to 2272. The same mix may have statistically different flow numbers, regardless of the contractor. The flow number increases with increasing effective binder content, air voids, voids in mineral aggregates, voids filled with asphalt, and asphalt content in the study range of these parameters. Full article
(This article belongs to the Special Issue Recent Advances and Future Trends in Pavement Engineering)
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Article
Ventilation of an Isolated Subsurface Structure Induced by Natural Forces
Infrastructures 2019, 4(2), 33; https://doi.org/10.3390/infrastructures4020033 - 05 Jun 2019
Cited by 5 | Viewed by 3123
Abstract
The subsurface infrastructure comprises many types of isolated structures, a type of confined space. This study reports on the effect of engine operating time, number/area and spacing of openings in the manhole cover, and operation during different seasons on ventilation of a subsurface, [...] Read more.
The subsurface infrastructure comprises many types of isolated structures, a type of confined space. This study reports on the effect of engine operating time, number/area and spacing of openings in the manhole cover, and operation during different seasons on ventilation of a subsurface, isolated, pre-cast concrete chamber through opening(s) in the manhole cover. Carbon monoxide (CO) emitted by a small gasoline engine reached 800 ppm in 30 s at the start of testing. Ventilation occurred continuously. Generally, the concentration of CO reported by instruments located at different heights was the same for the same moment in time, suggestive of a rapidly well-mixed atmosphere. Mathematical modelling suggested that ventilation occurred through a zero-order kinetic process. Statistical testing suggested that optimization of ventilation is possible through design modifications such as change in the number/area/shape/spacing/geometric arrangement of openings in the manhole cover. Optimizing the rate of ventilation induced by natural forces during the interval between entries will reduce the risk of explosion of the confined atmosphere and overexposure of workers when opening the manhole cover to prepare for entry. This improvement will have immense implications to safety worldwide. Full article
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Article
On the Use of Ensemble Empirical Mode Decomposition for the Identification of Bridge Frequency from the Responses Measured in a Passing Vehicle
Infrastructures 2019, 4(2), 32; https://doi.org/10.3390/infrastructures4020032 - 04 Jun 2019
Cited by 10 | Viewed by 3135
Abstract
In this paper, ensemble empirical mode decomposition (EEMD) and empirical mode decomposition (EMD) methods are used for the effective identification of bridge natural frequencies from drive-by measurements. A vehicle bridge interaction (VBI) model is created using the finite element (FE) method in Matlab. [...] Read more.
In this paper, ensemble empirical mode decomposition (EEMD) and empirical mode decomposition (EMD) methods are used for the effective identification of bridge natural frequencies from drive-by measurements. A vehicle bridge interaction (VBI) model is created using the finite element (FE) method in Matlab. The EMD is employed to decompose the signals measured on the vehicle to their main components. It is shown that the bridge component of the response measured on the vehicle can be extracted using the EMD method. The influence of some factors, such as the road roughness profile and measurement noise, on the results are investigated. The results suggest that the EMD shows good performance under those conditions, but the accuracy of the results may still need to be improved. It is shown that in some cases, the EMD may not be able to decompose the signal effectively and includes mode mixing. This results in inaccuracies in the identification of bridge frequencies. The use of the ensemble empirical mode decomposition (EEMD) method is proposed to overcome the mode mixing problem. The influence of factors such as road profile, measurement noise and vehicle velocity are investigated. It is numerically demonstrated that employing the EEMD improves the results compared to the EMD. Full article
(This article belongs to the Special Issue Innovate, Research, and Maintain Transportation Infrastructure)
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Article
Polymer Concrete for Bridge Deck Closure Joints in Accelerated Bridge Construction
Infrastructures 2019, 4(2), 31; https://doi.org/10.3390/infrastructures4020031 - 01 Jun 2019
Cited by 6 | Viewed by 4293
Abstract
Prefabricated concrete bridge deck panels are utilized in Accelerated Bridge Construction (ABC) to simplify bridge deck construction. Concrete with good bond and shear strength as well as excellent flowability is required to fill bridge deck closure joints. This paper discusses the use of [...] Read more.
Prefabricated concrete bridge deck panels are utilized in Accelerated Bridge Construction (ABC) to simplify bridge deck construction. Concrete with good bond and shear strength as well as excellent flowability is required to fill bridge deck closure joints. This paper discusses the use of polymer concrete (PC) for bridge deck closure joints in ABC. PC produced using poly methyl methacrylate and standard aggregate was tested. Test results of PC are compared to Ultra-High Performance Concrete (UHPC). Development length, lap splice length and shear strength of unreinforced PC were tested. It is shown that PC has a development length of 3.6 to 4.1 times the reinforcing bar diameter that is close to one-half the development length of 6 to 8 times the bar diameter required with UHPC. PC also showed a shorter splice length compared with that reported for UHPC. Finally, unreinforced PC showed shear strength that is twice that of UHPC. It is evident that using PC in bridge deck closure joints in ABC can improve constructability and provide cost-savings and eliminate reinforcing bar congestion. Full article
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Article
Post-Disaster Recovery Associations of Power Systems Dependent Critical Infrastructures
Infrastructures 2019, 4(2), 30; https://doi.org/10.3390/infrastructures4020030 - 29 May 2019
Cited by 3 | Viewed by 3706
Abstract
The complete failure of the power systems infrastructure in Puerto Rico, following Hurricanes Irma and Maria in 2017, severely hampered the recovery efforts of multiple critical infrastructure systems (CIS). Understanding the relationships of infrastructure recovery efforts between power infrastructure systems and the other [...] Read more.
The complete failure of the power systems infrastructure in Puerto Rico, following Hurricanes Irma and Maria in 2017, severely hampered the recovery efforts of multiple critical infrastructure systems (CIS). Understanding the relationships of infrastructure recovery efforts between power infrastructure systems and the other CIS has the potential to be a key in developing an effective recovery plan leading to resilient infrastructure systems, and thereby a more resilient community. This paper explores the critical interfaces and interdependencies in CIS recovery by examining the disruptions and recovery progress of the CIS, including the power infrastructure systems, in Puerto immediately following the events of Hurricane Maria. This research uncovers that strong CIS recovery interdependency relationships exist between the power infrastructure systems and other CIS in Puerto Rico, and these relationships contribute to the resilience of these CIS. The resultant CIS recovery associations may potentially predict the recovery progress of post-disaster CIS recovery centered on the power infrastructure systems and lay the groundwork for further interdependency analysis of CIS in post-disaster scenarios. The results may also be helpful while designing CIS for resiliency in natural disaster areas. Full article
(This article belongs to the Special Issue Resilient Infrastructure Systems)
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Article
Determination of Layers Responsible for Rutting Failure in a Pavement Structure
Infrastructures 2019, 4(2), 29; https://doi.org/10.3390/infrastructures4020029 - 26 May 2019
Cited by 7 | Viewed by 3281
Abstract
Rutting is one of the most common distresses in asphalt pavements in Zambia. The problem is particularly prevalent at intersections, bus stops, railway crossings, police checkpoints, climbing lanes and other heavily loaded sections, where there is deceleration, slow moving or static loading. The [...] Read more.
Rutting is one of the most common distresses in asphalt pavements in Zambia. The problem is particularly prevalent at intersections, bus stops, railway crossings, police checkpoints, climbing lanes and other heavily loaded sections, where there is deceleration, slow moving or static loading. The most widely used methods to identify the source of rutting among flexible pavement layers are destructive methods; field trenching and coring methods. The Transverse Profile Analysis method (TPAM), which is a non-destructive method, was suggested by White et al. in 2002 as an alternative method, to avoid the expensive and destructive nature of the traditional methods. In this method, data from the transverse profile of the rutted section is used to deduce the layer of the pavement structure responsible for rutting failure. This study used the TPAM to determine the layers of pavement responsible for rutting on sections of the Chibuluma and Kitwe-Chingola Roads in Zambia. The method was first validated using the trenching method on the Kitwe-Ndola Road. Results from the TPAM showed good comparability with those from the trenching method. It was established that most of the rutting emanated from the surfacing layer. This is consistent with recent research indicating that most rutting occurs in the upper part of the asphalt surfacing. It was also established that the TPAM was a simpler, faster and less costly method of determining the source of rutting failure compared to the traditional methods. Full article
(This article belongs to the Special Issue Recent Advances and Future Trends in Pavement Engineering)
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Review
Performance-Based Analysis in Civil Engineering: Overview of Applications
Infrastructures 2019, 4(2), 28; https://doi.org/10.3390/infrastructures4020028 - 23 May 2019
Cited by 2 | Viewed by 3891
Abstract
Traditional design approaches in civil engineering mainly focus on codes/guidelines related to building an infrastructure, while performance-based analysis (PBA), an emerging new reality around the world, focuses on the performance of the end product. Professional organizations, academicians, and the industry have made significant [...] Read more.
Traditional design approaches in civil engineering mainly focus on codes/guidelines related to building an infrastructure, while performance-based analysis (PBA), an emerging new reality around the world, focuses on the performance of the end product. Professional organizations, academicians, and the industry have made significant contributions in formulating PBA in various civil engineering fields, where practical guidelines and principles have been adopted in infrastructure analysis. This paper presents a critical review of PBA applications in three civil engineering fields: transportation, environmental, and structural engineering. The applications are grouped into a wide array of civil engineering areas, including highway transportation, pavement design and management, air transportation, water-structures design and operation, landfill design, building architectural design for evacuation, urban energy design, building earthquake-based design, building wind-based design, and bridge design and management. A total of 187 publications on PBA were reviewed and details on 122 application papers (from 23 countries/regions) are presented. The review consists of vertical and horizontal scans of PBA applications. In the vertical scan, the applications in each civil engineering area are summarized in tabular format that shows the system element modeled, analysis objective, performance criteria, analytical tool, and specifications/codes. The horizontal scan (discussion and lessons learned) addresses the following aspects of PBA: (1) the wide array of analytical tools used, (2) the broad functional and process-related areas, (3) the advantages, challenges, and opportunities, and (4) potential future applications. It is hoped that the state-of-the-art review presented in this paper will help researchers/practitioners quickly find useful information about PBA and promote its development in their respective fields. Full article
(This article belongs to the Special Issue Feature Papers)
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Article
Impacts of Seasonal and Annual Weather Variations on Network-Level Pavement Performance
Infrastructures 2019, 4(2), 27; https://doi.org/10.3390/infrastructures4020027 - 17 May 2019
Cited by 1 | Viewed by 3038
Abstract
This study was aimed to determine the extent of association between network-level pavement condition and seasonal and annual weather variations. Pavement condition data recorded in the Texas Department of Transportation’s Pavement Management Information System (PMIS) database between 2000 and 2008 was highlighted. Meteorological [...] Read more.
This study was aimed to determine the extent of association between network-level pavement condition and seasonal and annual weather variations. Pavement condition data recorded in the Texas Department of Transportation’s Pavement Management Information System (PMIS) database between 2000 and 2008 was highlighted. Meteorological data collected at different districts across the whole state were used in the explanatory variables. Dynamic panel data analysis was used in the deterioration models to quantify the effects of temperature and precipitation variations on pavement conditions. Based on the statistical implication from the model estimation results, significant correlations were identified between pavement conditions, the average monthly rainfall, and the average monthly temperature recorded 1 to 23 months prior to pavement condition inspection. Full article
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Article
Prediction of Compression Index of Fine-Grained Soils Using a Gene Expression Programming Model
Infrastructures 2019, 4(2), 26; https://doi.org/10.3390/infrastructures4020026 - 14 May 2019
Cited by 23 | Viewed by 3754
Abstract
In construction projects, estimation of the settlement of fine-grained soils is of critical importance, and yet is a challenging task. The coefficient of consolidation for the compression index (Cc) is a key parameter in modeling the settlement of fine-grained soil [...] Read more.
In construction projects, estimation of the settlement of fine-grained soils is of critical importance, and yet is a challenging task. The coefficient of consolidation for the compression index (Cc) is a key parameter in modeling the settlement of fine-grained soil layers. However, the estimation of this parameter is costly, time-consuming, and requires skilled technicians. To overcome these drawbacks, we aimed to predict Cc through other soil parameters, i.e., the liquid limit (LL), plastic limit (PL), and initial void ratio (e0). Using these parameters is more convenient and requires substantially less time and cost compared to the conventional tests to estimate Cc. This study presents a novel prediction model for the Cc of fine-grained soils using gene expression programming (GEP). A database consisting of 108 different data points was used to develop the model. A closed-form equation solution was derived to estimate Cc based on LL, PL, and e0. The performance of the developed GEP-based model was evaluated through the coefficient of determination (R2), the root mean squared error (RMSE), and the mean average error (MAE). The proposed model performed better in terms of R2, RMSE, and MAE compared to the other models. Full article
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Technical Note
Durable Bridge Columns using Stay-In-Place UHPC Shells for Accelerated Bridge Construction
Infrastructures 2019, 4(2), 25; https://doi.org/10.3390/infrastructures4020025 - 13 May 2019
Cited by 10 | Viewed by 4661
Abstract
Ultra-high performance concrete (UHPC) is a durable material that allows the construction of innovative structural elements and conforms with accelerated bridge construction (ABC) goals. The main idea of this research is to utilize UHPC to prefabricate a shell that acts as a stay-in-place [...] Read more.
Ultra-high performance concrete (UHPC) is a durable material that allows the construction of innovative structural elements and conforms with accelerated bridge construction (ABC) goals. The main idea of this research is to utilize UHPC to prefabricate a shell that acts as a stay-in-place form for bridge columns. The prefabricated shell eliminates the conventional formwork while reducing the on-site construction time and acting as a durable protective layer for the normal concrete inside the shell against environmental attacks. In addition, the UHPC shell provides additional confinement to the column concrete, which improves the column’s structural performance. During construction and after completing the column reinforcement work onsite, based on the conventional construction methods, the prefabricated UHPC shell is placed around the column reinforcement, followed by casting a portion of UHPC for a column-to-footing connection, which improves the capacity of the connection and shifts the plastic hinge zone above the connection. Once the UHPC portion hardens, normal concrete is placed inside the shell, forming a permanent concrete-filled UHPC shell. The construction process is finalized by placing and connecting a prefabricated cap beam to the column through the same developed connection as that in this research. This technical note presents the development of two test specimens using an UHPC shell in lieu of a conventional formwork with the advantage of improving the column performance and durability. Full article
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Article
Characterization of Recovered Bitumen from Coarse and Fine Reclaimed Asphalt Pavement Particles
Infrastructures 2019, 4(2), 24; https://doi.org/10.3390/infrastructures4020024 - 11 May 2019
Cited by 3 | Viewed by 3546
Abstract
In the current era of road construction, it is common to add a small amount of reclaimed asphalt pavement (RAP) in asphalt mixes without significantly changing properties such as stiffness and low-temperature cracking resistance. Not only can these mixes be better for the [...] Read more.
In the current era of road construction, it is common to add a small amount of reclaimed asphalt pavement (RAP) in asphalt mixes without significantly changing properties such as stiffness and low-temperature cracking resistance. Not only can these mixes be better for the environment, but they can also improve certain properties like rutting resistance. However, there is no clear understanding of how RAP gradation and bitumen properties impact the mixture properties. In this study, a single RAP source was separated into coarse and fine particles and added into a hot mix asphalt (HMA). Fourier transform infrared (FTIR) spectrometry was used to evaluate the chemical properties of the bitumen, while environmental scanning electron microscopy (ESEM) image analysis was used to visualize the differences of the virgin and RAP bitumen at a microscopic level. The observed results indicated that the recovered bitumen from coarse RAP did not have the same characteristics as the fine RAP bitumen, and the interaction of RAP bitumen with virgin bitumen significantly depended on RAP particle size. The amount of active RAP bitumen in coarse RAP particles was higher than in fine RAP particles. Full article
(This article belongs to the Special Issue Recent Advances and Future Trends in Pavement Engineering)
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Article
Surface Air Movement: An Important Contributor to Ventilation of Isolated Subsurface Structures?
Infrastructures 2019, 4(2), 23; https://doi.org/10.3390/infrastructures4020023 - 09 May 2019
Cited by 5 | Viewed by 3218
Abstract
This study reports on near-surface airspeed measured using a fast-responding thermoanemometer during an investigation of ventilation of an isolated subsurface structure induced by natural forces. Air speed changes continuously, rapidly, and unpredictably when assessed on the time base of one or two seconds. [...] Read more.
This study reports on near-surface airspeed measured using a fast-responding thermoanemometer during an investigation of ventilation of an isolated subsurface structure induced by natural forces. Air speed changes continuously, rapidly, and unpredictably when assessed on the time base of one or two seconds. Zero, the most common air speed, occurred in almost all tests throughout the year but especially during cool and cold months. The most probable non-zero air speed, 10.7 m/min (35 ft/min), occurred in all tests. This air speed is below the level of detection by the senses. The number of zero values and the height of the peak at 10.7 m/min follow a repetitive annual cycle. Isolated subsurface structures containing manhole covers share the characteristics of Helmholtz resonators. Grazing air flow across the opening to the exterior induces rotational air flow in the airspace of a Helmholtz resonator. Rotational flow in the airspace potentially influences the exchange of the confined atmosphere with the external one. Ventilation of the airspace occurs continuously and without cost and is potentially enhanced by the unique characteristics of the Helmholtz resonator excited by surface air movement. These results have immense importance and immediate applicability to worker safety. Full article
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Article
Show Me a Safer Way: Detecting Anomalous Driving Behavior Using Online Traffic Footage
Infrastructures 2019, 4(2), 22; https://doi.org/10.3390/infrastructures4020022 - 08 May 2019
Viewed by 3146
Abstract
Real-time traffic monitoring is essential in many novel applications, from traffic management to smart navigation systems. The large number of traffic cameras being integrated into urban infrastructures has enabled efficient traffic monitoring as an intervention in reducing traffic accidents and related casualties. In [...] Read more.
Real-time traffic monitoring is essential in many novel applications, from traffic management to smart navigation systems. The large number of traffic cameras being integrated into urban infrastructures has enabled efficient traffic monitoring as an intervention in reducing traffic accidents and related casualties. In this paper, we focus on the problem of the automatic detection of anomalous driving behaviors, e.g., speeding or stopping on a bike lane, by using the traffic-camera feed that is available online. This can play an important role in personalized route-planning applications where, for instance, a user wants find the safest paths to get to a destination. We present an integrated system that accurately detects, tracks, and classifies vehicles using online traffic-camera feed. Full article
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Article
Effect of Scour on the Natural Frequency Responses of Bridge Piers: Development of a Scour Depth Sensor
Infrastructures 2019, 4(2), 21; https://doi.org/10.3390/infrastructures4020021 - 07 May 2019
Cited by 8 | Viewed by 3508
Abstract
Local scour is the removal of soil around bridge foundations under the erosive action of flowing water. This hydraulic risk has raised awareness of the need for developing continuous monitoring techniques to estimate scour depth around bridge piers and abutments. One of the [...] Read more.
Local scour is the removal of soil around bridge foundations under the erosive action of flowing water. This hydraulic risk has raised awareness of the need for developing continuous monitoring techniques to estimate scour depth around bridge piers and abutments. One of the emerging techniques is based on monitoring the vibration frequency of either bridge piers or a driven sensor in the riverbed. The sensor proposed in this study falls into the second category. Some unresolved issues are investigated: the effect of the geometry and material of the sensor, the effect of the embedded length and the effect of soil type. To this end, extensive laboratory tests are performed using rods of different materials, with various geometries and lengths. These tests are conducted in both dry sand and a soft clayey soil. Since the sensor will be placed in the riverbed, it is crucial to evaluate the effect of immersed conditions on its response. A numerical 3D finite-element model was developed and compared against experimental data. This model was then used to compute the ‘wet’ frequencies of the sensor. Finally, based on both the experimental and numerical results, an equivalent cantilever model is proposed to correlate the variation of the frequency of the sensor to the scour depth. Full article
(This article belongs to the Special Issue Innovate, Research, and Maintain Transportation Infrastructure)
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Article
Mix Design and Mechanical Properties of Fly Ash and GGBFS-Synthesized Alkali-Activated Concrete (AAC)
Infrastructures 2019, 4(2), 20; https://doi.org/10.3390/infrastructures4020020 - 02 May 2019
Cited by 6 | Viewed by 3361
Abstract
Cement is one of the construction materials widely used around the world in order to develop infrastructure and it is also one of the factors affecting economies. The production of cement consumes a lot of raw materials like limestone, which releases CO2 [...] Read more.
Cement is one of the construction materials widely used around the world in order to develop infrastructure and it is also one of the factors affecting economies. The production of cement consumes a lot of raw materials like limestone, which releases CO2 into the atmosphere and thus leads to global warming. Many investigations are underway in this area, essentially focusing on the eco-accommodating environment. In the research, an alternative material to cement binder is geopolymer binder, with the same efficiency. This paper presents scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis of factory byproducts (i.e., fly ash and ground granulated blast furnace slag (GGBFS)). The mix design process for the manufacture of alkali-activated geopolymer binders synthesized by fly ash and GGBFS is presented. The mechanical properties (compression, split tensile and flexural strength, bond strength) of geopolymer concrete at different mix proportions and at dissimilar curing conditions were also investigated. Geopolymer concrete synthesized with 30% fly ash and 70% GGBFS has better properties at 14 M of NaOH and cured in an oven for 24 h at 70 °C. Full article
(This article belongs to the Special Issue Durability and Sustainability of Concrete Mixtures)
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Article
Benchmarking Image Processing Algorithms for Unmanned Aerial System-Assisted Crack Detection in Concrete Structures
Infrastructures 2019, 4(2), 19; https://doi.org/10.3390/infrastructures4020019 - 30 Apr 2019
Cited by 18 | Viewed by 3911
Abstract
This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, [...] Read more.
This paper summarizes the results of traditional image processing algorithms for detection of defects in concrete using images taken by Unmanned Aerial Systems (UASs). Such algorithms are useful for improving the accuracy of crack detection during autonomous inspection of bridges and other structures, and they have yet to be compared and evaluated on a dataset of concrete images taken by UAS. The authors created a generic image processing algorithm for crack detection, which included the major steps of filter design, edge detection, image enhancement, and segmentation, designed to uniformly compare different edge detectors. Edge detection was carried out by six filters in the spatial (Roberts, Prewitt, Sobel, and Laplacian of Gaussian) and frequency (Butterworth and Gaussian) domains. These algorithms were applied to fifty images each of defected and sound concrete. Performances of the six filters were compared in terms of accuracy, precision, minimum detectable crack width, computational time, and noise-to-signal ratio. In general, frequency domain techniques were slower than spatial domain methods because of the computational intensity of the Fourier and inverse Fourier transformations used to move between spatial and frequency domains. Frequency domain methods also produced noisier images than spatial domain methods. Crack detection in the spatial domain using the Laplacian of Gaussian filter proved to be the fastest, most accurate, and most precise method, and it resulted in the finest detectable crack width. The Laplacian of Gaussian filter in spatial domain is recommended for future applications of real-time crack detection using UAS. Full article
(This article belongs to the Special Issue Intelligent Infrastructures)
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Article
Chloride Penetration at Cold Joints of Structural Members with Dissimilar Concrete Incorporating UHPC
Infrastructures 2019, 4(2), 18; https://doi.org/10.3390/infrastructures4020018 - 24 Apr 2019
Cited by 6 | Viewed by 3389
Abstract
Ultra-high-performance concrete (UHPC) has been introduced for reinforced concrete structures due to its enhanced mechanical performance, including high compressive strength and tensile capacity. In certain applications, such as closure joints, connections, and concrete repairs, reinforcing steel may be embedded in dissimilar concrete elements [...] Read more.
Ultra-high-performance concrete (UHPC) has been introduced for reinforced concrete structures due to its enhanced mechanical performance, including high compressive strength and tensile capacity. In certain applications, such as closure joints, connections, and concrete repairs, reinforcing steel may be embedded in dissimilar concrete elements partially incorporating UHPC. Superficially, UHPC can be considered to provide enhanced corrosion durability in marine environments due to its low permeability which would mitigate chloride-induced corrosion of rebar in the bulk material. However, the chloride intrusion through cold joints can be faster than that in bulk concrete and may jeopardize the durability of structures. This research examines the possibility of enhanced chloride transport at the cold joint incorporating UHPC. The effectiveness of the bond on chloride penetration at the concrete interface with various levels of moisture availability for the substrate at the time of UHPC repair was examined. To this effect, the substrate concrete was conditioned to different moisture content including 0%, 75%, and 100% relative humidity, and soaked prior to UHPC repair concrete casting. Chloride penetration was accelerated by an impressed current source and assessed by silver nitrate solution sprayed on the cold joint. Moreover, the tensile bond strength between substrate concrete and UHPC was measured using the splitting tensile test. Full article
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Article
Location Allocation of Sugar Beet Piling Centers Using GIS and Optimization
Infrastructures 2019, 4(2), 17; https://doi.org/10.3390/infrastructures4020017 - 23 Apr 2019
Cited by 1 | Viewed by 3076
Abstract
The sugar beet is one of the most important crops for both social and economic reasons, even though the area under sugar beet cultivation in the Red River valley of North Dakota and Minnesota is comparatively smaller that of corn and other crop [...] Read more.
The sugar beet is one of the most important crops for both social and economic reasons, even though the area under sugar beet cultivation in the Red River valley of North Dakota and Minnesota is comparatively smaller that of corn and other crop lands. It generates a large economic activity in local and regional level with a greater impact on jobs and stimulation of agriculture, transportation, and farm economy. Sugar beet transportation takes place in two stages in Red River Valley: the first step is from farms to piling centers (pilers) and the second step from pilers to processing facilities. This study focuses on the problem of optimizing piler locations based on supply variation. Sugar beet supply and harvest varies significantly due to numerous reasons such as weather, water availability, and different maturity dates for the crop. This provides for a variable optimal harvesting time based on the plant maturity and sugar content. Sub-optimized pilers location result in the high transportation and utilization costs. The objective of this study is to minimize the sum of transportation costs to and from pilers and the pilers utilization cost. A two-step algorithm based on the geographical information system (GIS) with global optimization method is used to solve this problem. This method will also be useful for infrastructure decision makers such as planners and engineers to predict the truck volume on rural roads. Full article
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Article
Fatigue Stress-Life Model of RC Beams Based on an Accelerated Fatigue Method
Infrastructures 2019, 4(2), 16; https://doi.org/10.3390/infrastructures4020016 - 20 Apr 2019
Cited by 1 | Viewed by 3071
Abstract
Several standard fatigue testing methods are used to determine the fatigue stress-life prediction model (S-N curve) and the endurance limit of Reinforced Concrete (RC) beams, including the application of constant cyclic tension-tension loads at different stress or strain ranges. The standard fatigue testing [...] Read more.
Several standard fatigue testing methods are used to determine the fatigue stress-life prediction model (S-N curve) and the endurance limit of Reinforced Concrete (RC) beams, including the application of constant cyclic tension-tension loads at different stress or strain ranges. The standard fatigue testing methods are time-consuming and expensive to perform, as a large number of specimens is needed to obtain valid results. The purpose of this paper is to examine a fatigue stress-life predication model of RC beams that are developed with an accelerated fatigue approach. This approach is based on the hypothesis of linear accumulative damage of the Palmgren–Miner rule, whereby the applied cyclic load range is linearly increased with respect to the number of cycles until the specimen fails. A three-dimensional RC beam was modeled and validated using ANSYS software. Numerical simulations were performed for the RC beam under linearly increased cyclic loading with different initial loading conditions. A fatigue stress-life model was developed that was based on the analyzed data of three specimens. The accelerated fatigue approach has a higher rate of damage accumulations than the standard testing approach. All of the analyzed specimens failed due to an unstable cracking of concrete. The developed fatigue stress-life model fits the upper 95% prediction band of RC beams that were tested under constant amplitude cyclic loading. Full article
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Article
Stability Assessment of Earth Retaining Structures under Static and Seismic Conditions
Infrastructures 2019, 4(2), 15; https://doi.org/10.3390/infrastructures4020015 - 09 Apr 2019
Cited by 1 | Viewed by 3160
Abstract
An accurate estimation of static and seismic earth pressures is extremely important in geotechnical design. The conventional Coulomb’s approach and Mononobe-Okabe’s approach have been widely used in engineering practice. However, the latter approach provides the linear distribution of seismic earth pressure behind a [...] Read more.
An accurate estimation of static and seismic earth pressures is extremely important in geotechnical design. The conventional Coulomb’s approach and Mononobe-Okabe’s approach have been widely used in engineering practice. However, the latter approach provides the linear distribution of seismic earth pressure behind a retaining wall in an approximate way. Therefore, the pseudo-dynamic method can be used to compute the distribution of seismic active earth pressure in a more realistic manner. The effect of wall and soil inertia must be considered for the design of a retaining wall under seismic conditions. The method proposed considers the propagation of shear and primary waves through the backfill soil and the retaining wall due to seismic excitation. The crude estimate of finding the approximate seismic acceleration makes the pseudo-static approach often unreliable to adopt in the stability assessment of retaining walls. The predictions of the active earth pressure using Coulomb theory are not consistent with the laboratory results to the development of arching in the backfill soil. A new method is proposed to compute the active earth pressure acting on the backface of a rigid retaining wall undergoing horizontal translation. The predictions of the proposed method are verified against results of laboratory tests as well as the results from other methods proposed in the past. Full article
(This article belongs to the Special Issue Seismic Resilient Infrastructures)
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Article
Identifying and Measuring Engineering, Procurement, and Construction (EPC) Key Performance Indicators and Management Strategies
Infrastructures 2019, 4(2), 14; https://doi.org/10.3390/infrastructures4020014 - 29 Mar 2019
Cited by 13 | Viewed by 4566
Abstract
Delay and cost overrun in construction projects are two widespread problems that arouse practitioners’ and scholars’ concern. Therefore, the objective of this study was to identify Key Performance Indicators (KPIs) in each of Engineering, Procurement and Construction (EPC) phases separately and then calculate [...] Read more.
Delay and cost overrun in construction projects are two widespread problems that arouse practitioners’ and scholars’ concern. Therefore, the objective of this study was to identify Key Performance Indicators (KPIs) in each of Engineering, Procurement and Construction (EPC) phases separately and then calculate the weight impact that is associated with each of identified KPIs. Additionally, this study aimed to find the most appropriate Best Practices (BPs) for the identified phase-based indicators. Through a review of existing literature, a survey was developed to collect data from the completed construction projects. Various statistical methods, including two sample T-test and Kruskal-Wallis test, were utilized to analyze the data. Subsequently, Epsilon-Squared effect size method was applied to prioritize the identified KPIs. Since the lack of communication and slowness in decision making were found as the primary schedule Performance Indicators, schedule performance was identified to be highly affected by managerial approaches and actions. In addition, clients play a decisive role, because owner-driven change orders were found as the most crucial cost performance indicator affecting the performance of the engineering and construction phases. The outcome of this study helps practitioners and scholars to understand the phase-based cost and schedule KPIs, and appropriate mitigating strategies to improve the construction performance in EPC phases and save time and money. Full article
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Article
Force Performance Analysis of Pile Behavior of the Lateral Load
Infrastructures 2019, 4(2), 13; https://doi.org/10.3390/infrastructures4020013 - 28 Mar 2019
Viewed by 3250
Abstract
This study was focused on the performance of the pile force at the lateral load of an arched bridge. The effect of the compression of arch bridges creates a large horizontal load. Therefore, it is one of the most important factors in the [...] Read more.
This study was focused on the performance of the pile force at the lateral load of an arched bridge. The effect of the compression of arch bridges creates a large horizontal load. Therefore, it is one of the most important factors in the dimensioning of piles. The study aims to make a comparative study between the results obtained in the field, and those obtained by a 3D model defined as a Finite Element (FE) of a drilled pile, subjected to different lateral loads applied at exact time intervals. Moreover, the study was intended to determine the influence of the lateral load applied to a different pile diameter using the FE model. Thus, the unified FEA software Abaqus™ by Dassault systèmes® carried out various processing procedures, namely soil FE modeling, pile FE modeling, soil-pile interface, Mesh, and boundary conditions, to carry out an effective and predictive piles behavior analysis. Based on the Mohr-Coulomb criterion, the soil is considered to be stratified with elastoplastic behavior, whereas the Reinforcement Concrete Pile (RCP) was assumed to be linear isotropic elastic, integrating the concrete damage plasticity. Since the bridge is an arched bridge, the lateral load induced was applied to the head of the piles through a concentrated force to check the pile strength, for which the displacement, stress and strain were taken into account throughout, along the pile depth. The lateral displacement of the pile shows a deformation of the soil as a function of its depth, with different layers crossed with different lateral loads applied. Thus, from the study comparing the results of the FE measurements with the data measured in the field, added to the statistical analyses are as follows: Decrease of the displacement and stress according to the diameter, taking into account the different diameter. The foundations receive loads of the superstructure to be transmitted to the ground. Thus, the piles are generally used as a carrier transmitting loads on the ground. One of the important factors in the durability of the bridge depends more on the strength of these piles. This makes it necessary to study the reinforced concrete foundations because of their ability to resist loads of the structure, and the vertical and lateral loads applied to the structure. This implies an evaluation of the responses of the RCP according to the different lateral loads. Full article
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