rss_2.0Romanian Journal of Transport Infrastructure FeedSciendo RSS Feed for Romanian Journal of Transport Infrastructure Journal of Transport Infrastructure 's Cover of the Effect of the Deck Material on the Cost in Cable-Stayed Bridges with Different Spans<abstract> <title style='display:none'>Abstract</title> <p>Recent developments in the social sphere also cause an increase in transportation activities. Increased transport activities lead to the construction of new roads and bridges. Different bridge construction systems are available to overcome large span obstacles. Cable-stayed bridges are more advantageous construction systems than other bridge type building carrier systems in overcoming large spans through suspension cables. Therefore, it is also widely preferred by designers. The biggest factor in the development of cable-stayed bridges is undoubtedly steel cables. Cable-stayed bridges are bridge structures that become lighter with the increase of the span, which has a more expanded flexibility, and that includes a cable system with the effect of nonlinear factors. Costs of cable-stayed bridges vary according to different spans. The span as well as the deck material used in the bridge system have a great effect on the cost. In cable-stayed bridge systems, decks are constructed of reinforced concrete and steel.</p> <p>The costs of cable-stayed bridges are widely discussed around the world; therefore, the effect of the span and deck material on the cost of cable-stayed bridges is being investigated. The main bearing elements of such bridges are cables, decks, and towers, and among these elements, the tower bridge carries all the weight of the bridge, even other external loads such as vehicle, wind, etc. In this study, the three-dimensional model of the cable, deck and tower elements that make up the cable-stayed bridge system was created and analysed using the CSI Bridge Program. The AASHTO LRFD Standards, which are widely used in the analysis of bridge systems with the CSI Bridge program and the design of bridge systems in the world, were used. In the study, the analysis and designs of cable-stayed bridges with reinforced concrete and steel deck at 250, 500, 750, 1000, 1500, 2000 meters span were carried out. The amount of materials and costs used in the analysis and design of the cable-stayed bridge systems were obtained and the results were interpreted.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Carbonation Resistance Classes of Concretes<abstract> <title style='display:none'>Abstract</title> <p>Concrete carbonation is a phenomenon that occurs by the penetration into the cement stone of CO<sub>2</sub> present in the atmosphere. The phenomenon occurs in the presence of water in which CO<sub>2</sub> dissolves, forming carbonate ions, which in turn react with calcium ions in the pores of the concrete, resulting in calcium carbonate (calcite). The diffusion of CO<sub>2</sub> occurs through pores and surface defects, it thus penetrates deeper into the concrete and the carbonation reaction can occur at a greater depth, eventually exceeding the thickness of the cover, causing corrosion of the reinforcement. [1]</p> <p>In the case of reinforced concrete bridges, corrosion induced by carbonation of concrete is one of the main causes of degradation. Thus, in the design stage of the reinforced concrete bridge structures, the inevitable process of carbonation of the concrete must be taken into account, in the design of the durability, by calculating the thickness of the concrete cover layer.</p> <p>This article aims to present the concept of carbonation resistance class, which will be a major change in the standard based on which the thickness of the concrete cover for reinforcement will be determined. This presentation is made in the context of the European performance approach to durability. In this sense, an analysis of the experimental results obtained in research on concrete prepared with different types of cements, carried out in collaboration with the laboratory of the Reinforced Concrete Structures Department, within the Technical University of Civil Engineering Bucharest. Proposals for classification in the carbonation resistance classes for concretes prepared with two types of cements are also presented.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Static and Dynamic Structural Health Monitoring System for Bridges<abstract> <title style='display:none'>Abstract</title> <p>This document describes a system for static and dynamic monitoring of the structural health of bridges, but not only. The need to develop the system resulted from the difficulties encountered by the authors in installing and operating complex monitoring systems, composed of elements from different manufacturers, with different measurement technologies, power supplies, communication modes and software applications. The described system facilitates the integration of different measurements, sensors, power supplies and communication technologies, in a unitary system that allows both static and dynamic measurements, simultaneously.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Research on the Parameters Influencing the Numerical Analysis of the Fatigue Behaviour of a Forklift-ARM<abstract> <title style='display:none'>Abstract</title> <p>Estimating the remaining service life of a forklift for an objective reference is not only a requirement of the applicable legislation but also represents a challenge for specialized technical staff.</p> <p>It is well known that the first fatigue failure element of a forklift is its fork. A simulation using the SolidWorks suite and its result is presented in this article. It allows the identification of critical areas of fatigue failure.</p> <p>Based on the design of the subassembly and the loading scheme of the original product, the model under analysis with finite element was made on a 1: 1 scale. The filet areas also required a comparative analysis of the results obtained depending on the choice of mesh and discretization element.</p> <p>Starting from the mechanical properties of the material as well as the association with the characteristic fatigue yield curves (Wohler), a method for estimating the remaining service life of the structure is proposed. The aspect related to obtaining exact results without an excessive consumption of computing resources was also taken into account.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Effects of Coarse Aggregate Shape and Texture on Engineering Properties of Roller Compacted Concrete Prepared for High Traffic Routes<abstract> <title style='display:none'>Abstract</title> <p>Use of roller-compacted concrete in pavement construction is increasing. Roller compacted concrete is a zero-slump, highly compacted concrete that is placed by equipment similar to that used in asphalt pavement construction. This investigation was conducted to collect the state-of-the-art information on effects of coarse aggregate size and texture on the strength and workability of roller-compacted concrete (RCC) for pavement construction and maintenance. Concrete specimens containing cubical and rough coarse aggregate, irregular and rough coarse aggregate, angular and rough coarse aggregate, rounded/spherical and smooth coarse aggregate, and flaky/elongated and rough coarse aggregate were prepared at 1:3:3 concrete mix ratio and 0.4 water cement ratio. Laboratory testing of specimens derived from the concrete specimens showed excellent results for cubical and rough coarse aggregate, irregular and rough coarse aggregate, and angular and rough coarse aggregate. Specimens from the rounded/spherical and smooth coarse aggregate, and flaky/elongated and rough coarse aggregate performed poorly in laboratory. The study therefore recommends the use of cubical and rough coarse aggregate, and irregular and rough coarse aggregate in the production of roller-compacted concrete for pavement construction and maintenance.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Characterization of Coconut Shell Ash and Eggshell Powder as Supplementary Cementitious Materials in Roller Compacted Concrete Industrial Access Pavements and Parking Facilities<abstract> <title style='display:none'>Abstract</title> <p>The cost of cement used in concrete works is on the increase and unaffordable, yet the need for hydraulic cement concrete and other cement concrete based infrastructures keeps growing with increasing population, thus the need to find alternative binding materials that can be used solely or in partial replacement of cement. The use of waste materials with pozzolanic properties in concrete production is a becoming a worldwide practice. The assessment of the pozzolanic activity of cement replacement materials is becoming increasingly important because of the need for more sustainable cementing products. In this study, a mixture of coconut shell ash and eggshell powder is used as partial replacement of hydraulic cement in ranges of 0%, 5%, 10%, 15%, and 20%. The concrete specimens were prepared at 1: 3: 2.5 mix ratio of cementitious material, fine aggregate and coarse aggregate. The mix ratio satisfied the minimum cement content of 148.32kg/m<sup>3</sup> (250Ib/yd<sup>3</sup>) and the minimum cementitious material content of 267 kg/m<sup>3</sup> (450Ib/yd<sup>3</sup>) for roller compacted concrete pavement. The compressive strength, splitting tensile strength and flexural strength tests were carried out to assess the strength characteristics of ternary concrete mixture containing coconut shell ash and eggshell powder and the feasibility of using coconut shell ash and eggshell powder as partial replacement of cement in industrial plant access concrete roads and parking lots. The results indicate that a mixture of coconut shell ash and eggshell powder can be used up to 20% by weight for replacement of cement in roller compacted industrial plant access concrete roads and parking lots.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Accelerated Laboratory Testing for Reflective Cracking<abstract> <title style='display:none'>Abstract</title> <p>One of the most used methods of rehabilitation of road structures is the laying of a protective asphalt layer over a degraded concrete. The main problem of this solution is the reflective cracking, more precisely the transmission of the existing cracks in the lower layer in the asphalt pavement.</p> <p>The method presented in this article involves an accelerated laboratory test on specimens composed of a pre-cracked concrete slab over which an asphalt slab is glued, subjected to equivalent traffic loads. This test allows the observation of the crack propagation from the lower layer to the upper layer, until it yields, through parameters such as deformed specimen, opening and length of the crack in asphalt, but also the opening of the existing crack in concrete, relative to the number of cycles.</p> <p>By relating these parameters, important conclusions can be drawn about the behavior of the composite structure at reflective cracking, being able to choose the optimal recipe of the protective asphalt layer.</p> </abstract>ARTICLE2021-08-30T00:00:00.000+00:00Vertical Interaction Between a Driving Wheelset and Track in the Presence of the Rolling Surfaces Harmonic Irregularities<abstract><title style='display:none'>Abstract</title><p>The driving wheelset is used in railway traction (locomotives, electric trains, trams, etc.) to support part of the weight of the suspended mass and to drive and brake the vehicle. The dynamics of the driving wheelset/track system is a very important issue in the railway engineering, and this paper is focused on basic features of the frequency response functions which describe the dynamic behavior in the presence of the rolling surfaces harmonic irregularities. To this end, a simple model of the driving wheelset/track system with the range of application limited up to 6-700 Hz is adopted. The driving wheelset model consists of a free-free uniform Euler-Bernoulli beam with three attached rigid bodies, representing the axle, the two wheels and the gear; the distinct feature of this model is the inertial asymmetry. Two independent infinite uniform Euler-Bernoulli beams, each on its foundation including two elastic layers for rail pad and ballast and an intermediate inertial layer for sleepers represent the track model. For simplicity, the moving irregularity model is applied to simulate the interaction between wheels and rails. Numerical simulations show that the driving wheelset/track system has three resonance frequencies, all situated in the frequency range of the evanescent waves in rails. FRF of the driving wheelset/track system have been calculated for left and right wheel/rail pair. The influence of the asymmetric inertia of the driving wheelset and the out of phase between the rolling surface irregularities are evaluated in terms of frequency response functions of the wheel/rail contact force.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Sustainable Urban Transport on Three Wheels<abstract><title style='display:none'>Abstract</title><p>Many of our global warming problems come from transport. The majority of people who need transport the most in the developing world are too poor to pay for the highest-technology vehicles which are not polluting. In the past 10 years, 3-6-passenger, battery-powered, Small Electric Passenger Vehicles (as this article is calling them, SEPVs) have appeared in major cities in the developing world. These slow, relatively safe, easily maneuverable, non-polluting and low-cost vehicles, on their three little wheels, are cutting the size of the world’s transport carbon footprint. Recognize that this paper is only focused on carbon footprint: carbon emissions. It is not about “pollution in general” or “emissions in general”. No other published article has explicitly considered the potential of the SEPV to contribute in reducing a nation's contribution to carbon footprint and thus to global warming. This article makes the case for building urban transport strategy and policy around such vehicles, in developing countries, in order to lower the countries' carbon footprint: that is its original contribution. The data showed that the SEPVs made a significant contribution to reducing the potential carbon footprint of transport in the small city of Cox’s Bazar, in Bangladesh, proportionate to its population. The inference is that SEPVs could reduce the carbon footprint of the nation if they become a major, integrated part of urban transport in the megacities, which creates most of the country's carbon footprint. Other developing countries should study Cox's Bazar's example. India is already ahead of the game.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Special-Purpose River-Port Sediment Valorization as Road Construction Material Emphasising Environmental Aspects<abstract><title style='display:none'>Abstract</title><p>Special-purpose river port sediment was investigated for its potential use as a road construction material. Sediment samples were extracted from three locations in three small river ports, and detailed laboratory research was conducted to determine its basic mechanical properties and characteristics that can potentially have an adverse influence in a roadside environment. The results of the research conducted indicate that there is a need for systematic monitoring of the quality and quantity of sediment in special-purpose river ports of the Danube River Basin to maintain its mobility and prevent flooding. The basic engineering characteristics (Proctor elements, Atterberg limits, California bearing ratio, and unconfined compressive strength) determined represent the good potential of the sediment samples tested herein for use in road construction. In addition, the chemical characteristics tested indicate the need for detailed analyses of the potential environmental risk before application in civil engineering structures</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Residents’ Willingness to Adopt Cycling as Intra-City Transport in Calabar, Nigeria<abstract><title style='display:none'>Abstract</title><p>This study investigated the willingness of residents to use bicycles for intra-city transportation in Calabar, South-South Nigeria. Administered questionnaires were successfully retrieved (82%) from residents of all income and employment groups in the 22 political wards of the study area. Stratified sampling technique was used to select survey participants. Initial socioeconomic characteristics of respondents in intercept only model was used to predict the willingness of respondents to ride in the city. Twelve problems of bicycle transportation were further presented to participants who rated them using a six-point scale (1-6), highly unwilling to highly willing to ride, respectively. Logistic Regression Analysis was employed to predict the probability that a respondent would be willing to ride. The predictor variables were respondents’ gender, age, education, occupational status, 12 bicycle infrastructure characteristics and dummy variables coding each socioeconomic scenario. A test of the full model versus a model with intercept only was statistically significant, χ2 (24, N = 315) = 50.5, p &lt; .001 and χ2 (19, N = 315) = 36.5, p &lt; .001. The model was able to correctly classify 86% of those willing to ride and 29.1% of those unwilling to ride, for an overall success rate of 66.2%. The study revealed that there is no gender sensitivity in the willingness of residents to ride in the city. In model 2, the odd ratio of some bicycle infrastructure characteristics such as bicycle lanes (1.181), conflicts with motorist (1.338), lack of respect for cycling (1.078), culture/stigma (1.046), weather (1.013), potholes (1.222), safety issues (1.280), and illumination (1.241) are more significant in predicting the probability of respondents to ride bicycles. The study recommended designated bicycle paths/trails to motivate residents to ride bicycles in the city.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Freeze/Thaw Resistance Classes of Concretes<abstract><title style='display:none'>Abstract</title><p>The freeze/thaw phenomenon is of interest for the field of transport infrastructure through the degradations it produces in the structure of construction elements. The climatic specificity of Romania on the one hand and the exposure to aggressive environments of construction elements in transport on the other hand, determine the importance of studying this phenomenon, its mode of action/propagation and also prevention and maintenance to ensure the functionality of buildings in transport infrastructure.</p><p>Currently, in the Romanian regulations [*], the assurance of sustainability is done, as in most national annexes for the application of EN 206 [1] in Europe, by a descriptive approach (concrete “designed to last”) referring to (with mandatory status) a series of requirements of the concrete composition (water / cement ratio, minimum cement dosage, entrained air, freeze/thaw resistant aggregates, etc.) and to the compressive strength (concrete compressive strength class) in depending on the classification of the element in a certain exposure class “X”.</p><p>The support of this descriptive national approach was based on the analysis of a large number of results obtained in a complex experimental program carried out by Technical University of Civil Engineering Bucharest, by analyzing the results obtained by laboratory tests on “candidate” cements and cements “reference” (having a good behavior and traditional use) as well as “in situ” tests/determinations on construction elements made with both categories of cements and maintained in specific environments.</p><p>At European level, performance approaches to sustainability have made clear progress. The development of accelerated laboratory experimental methods, the establishment of performance criteria, classes of resistance to various environmental actions and the link between them and the classes of exposure to various environmental actions were the starting point for experimental research whose results will be presented in this article.</p><p>Thus, in conjunction with these modern approaches, an analysis will be presented on the experimental results obtained in research on freeze/thaw resistance to different types of cements, carried out in collaboration with the laboratory of the Reinforced Concrete Structures Department, Technical University of Civil Engineering Bucharest and proposals for classification in different classes of freeze/thaw resistance.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Asphalt Mixtures with Limestone Aggregate for Base Layer<abstract><title style='display:none'>Abstract</title><p> Asphalt mixtures are mixtures of mineral aggregates, filler, bitumen and eventually additives in proportions determined by recipe designed in the laboratory. Asphalt mixtures used as base course are bituminous concrete. </p><p>The natural aggregates are granular materials of mineral origin that come from natural or artificial crushing of the rocks. In our country there are the various rocks: eruptive or magmatic rocks, metamorphic rocks, sedimentary rocks. </p><p>To the category of sedimentary rocks belong limestone. Sedimentary rocks are characterized by relatively high porosity and a pronounced stratification, which causes mechanical resistance to be low and vary by direction of load. Due to the structure less dense and weaker mechanical resistance, the limestone are used less in heavy traffic pavement structures. </p><p>This paper presents an asphalt mixture recipe for the base layer developed in the Laboratory of Roads from Technical University of Civil Engineering Bucharest (TUCEB), using limestone aggregates extracted from Hoghiz Quarry. The paper contains laboratory test results to determine the recipe and laboratory findings leading to the schedule of product.</p></abstract>ARTICLE2015-02-06T00:00:00.000+00:00Some Investigations Performed for the Bridge Over Jiu at Aninoasa<abstract><title style='display:none'>Abstract</title><p> The carrying structure of the bridge over the Jiu River at Aninoasa consists in two parallel concrete arches with variable height of the cross section, sustaining a concrete deck through vertical concrete hangers. In the time period passed since the bridge was erected, some structural elements shown damages. In order to establish the technical state of the bridge, a technical appraisement was performed and according to this, the most exposed elements to the risk of failure are the hangers. </p><p>The purpose of this paper is to present briefly both, the method used to test the actual bridge carrying capacity in situ and the finite element model developed for the static and dynamic analysis of the structure. </p><p>In order to estimate the state of the structural elements, two ways were followed. In the first stage, a test project was carried out and in the second stage, a complete 3D finite element model was developed to analyze the bridge structure. </p><p>The test project has foreseen the loading of the bridge by heavy unloaded trucks, disposed in some positions on the deck and the measurements of the deck and arches displacements. The positions of the trucks were established in order to obtain the maximum values both for arches transverse displacements and vertical displacements of the deck. Using electro-resistive transducers the hangers elongations and strains values on their cross section were also measured. These measured values were compared with those obtained from the numerical calculations performed by using the complete finite element model. By means of the finite element model, also the response of the structure following the dynamic action of vehicles was investigated.</p></abstract>ARTICLE2015-02-06T00:00:00.000+00:00Transport Demand Forecast on Pan-European Road Corridor X. Methodology, Results and their Assessment Through Comparisons with Actual Demand<abstract><title style='display:none'>Abstract</title><p> Transport demand forecast is a crucial parameter for transport planning. It defines the infrastructure dimensioning for a required level of service in a planning period, but moreover, it is determinative in the socioeconomic and financial feasibility study of transport projects. This paper presents the methodology and the results of the traffic flows forecasting exercise for the Pan-European Corridor X, which was elaborated to serve as a sound basis for documentation of the transport investments priorities, and the assessment of the results of the forecasted demand through comparisons with actual demand.</p></abstract>ARTICLE2015-02-06T00:00:00.000+00:00Traffic Lights on Consecutive Intersections and Pedestrian Crossings Along Linear Settlements Located on National Roads<abstract><title style='display:none'>Abstract</title><p> In Romania, with time, settlements located along the main roads have developed and transformed into linear towns, with significant local and connection traffic, important administrative, economic, commercial and touristic activities concentrated in the central area, as well as pedestrian traffic of over 200 pedestrians per hour in the main pedestrian crossings on the route. </p><p>The object of the present study is made by a series of junctions situated on National Road 1 in Busteni town, on a dangerous road sector. For this study, traffic measurements, simulations and suggestions for improving the existing situation were made. </p><p>Based on the simulated traffic flows, there were performed capacity analysis with PTV Vissim and Traficware Synchro softwares, and were developed appropriate planning solutions for the intersections, resulting in tables with extracted performance indicators based on micro simulation of the traffic values. Also planning solutions for horizontal design and proposals for traffic lights were made for junctions that can not operate under priority traffic on one direction or which are presenting traffic safety risk. </p><p>Based on the traffic data, it was taken in consideration the necessity to make planning proposals and to develop design solutions immediately applicable, with minimum intervention. </p><p>Solutions will refer to the geometric planning of the intersections, but with new plans and timings for traffic lights, including proposals for new equipment; regulating the traffic flow: development/ refurbishment of intersections and pedestrian crossings; optimization of routing programs in order to achieve a higher level of service and more efficient traffic control indicators; segregation of pedestrian movements by vehicles traffic, implementation of physical devices to lock / channel the traffic.</p></abstract>ARTICLE2015-02-06T00:00:00.000+00:00The Distance Between Real Time Data and Decision Making in Urban Road Freight Transportation Systems; The Example of the City of Thessaloniki<abstract><title style='display:none'>Abstract</title><p> Road freight transport in urban areas (city logistics) is under study worldwide, especially during the last years, mainly due to its negative impacts to the environment and to the efficient operation of the road network. The modern approach to deal with this rising issue includes the deployment of strategies and measures that take into consideration the conditions prevailing in each study area. In order the decision makers to adopt the proper measures and define the strategy, it is vital for them to have full knowledge of the way an Urban Road Freight Transportation (URFT) system is organized and functions in the field. For this to happen, the decision makers must have under their disposal reliable real time data. After all URFT systems evolve through time and space and it is s crucial that the necessary data not only will be collected correctly but also they will be accessible anytime and anywhere. In this paper a new approach is proposed in order to achieve real time monitoring for URFT systems in order to provide the decision makers with all the necessary data for the case of Greece.</p></abstract>ARTICLE2015-02-06T00:00:00.000+00:00Microfibre Reinforced Hot Mix Asphalt<abstract><title style='display:none'>Abstract</title><p> Cracks are common disturbances in pavement structure. The ability of hot mix asphalt to withstand tensile stresses is limited. This paper presents influence of different microfiber reinforcement types ITERFIBRA to hot mix asphalt behaviour in its chosen properties. Bulk density of hot mix asphalt, stiffness , resistance to the permanent deformation and resistance to the crack propagation are taken into consideration.</p></abstract>ARTICLE2015-02-06T00:00:00.000+00:00Loessoid Soils Improvement – Laboratory Tests and Road Engineering Applications<p>Moisture-sensitive or collapsible soils are materials with high porosity that under the loads transmitted by the superstructure or even under its own weight present additional settlements once the soil is saturated. This category includes loess deposits and other high silt content soils with uneven porosity. A method often used for foundation on these soils is the realization of local loessoid material compacted columns. This paper presents, on one hand, the experimental laboratory programs aiming to achieve some optimal mixtures of local material (loess) and different other materials (sand, bentonite, cement) in order to improve the values of the mechanical parameters of the soil and so, to limit the settlements. On the other hand, it presents a lot of settlement calculations for different case scenarios.</p>ARTICLE2019-11-12T00:00:00.000+00:00Study of the Influence of Fibres Type and Dosage on Properties of Concrete for Airport Pavements<p>The paper follows the potential practice of fiber reinforced concrete (FRC) as a solution for airport`s runway pavements, in order to increase the bearing strength, resulting in decreasing the height of the concrete layer that is currently used.</p>ARTICLE2019-11-12T00:00:00.000+00:00en-us-1