rss_2.0Ovidius University Annals of Constanta - Series Civil Engineering FeedSciendo RSS Feed for Ovidius University Annals of Constanta - Series Civil Engineering University Annals of Constanta - Series Civil Engineering 's Cover200300Product differentiation policy of the construction firm<abstract><title style='display:none'>Abstract</title><p> Usually, the possibility of product differentiation of the construction company is defined as restricted, limited. Product differentiation as a key element of product policy aims to create a sustainable competitive advantage in the minds of consumers, using tangible and intangible characteristics and product properties compared to the next strongest competitor. The ability of any company to differentiate their own product makes it distinct from competitors and gives the opportunity to control the market and build competitive advantages. The aim of the study is to prove: 1) The need to differentiate the product of the construction company, 2) Guidelines for differentiation of the construction product taking into accounts the specifics of the construction market, product and process.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Relining of pipe systems: conditions, benefits and application through case-study<abstract><title style='display:none'>Abstract</title><p> Relining is one of the best alternatives available today for pipe system rehabilitation. This trenchless solution is particularly interesting for urban agglomerations, as a smaller diameter pipe is pushed or pulled through the old pipeline. Relining creates a leak-tight “pipe within a pipe” system, which is as good as new in both structural and hydraulic terms. Relining can be performed with both circular and special, non-circular (NC) profiles. The latter is especially advantageous for the rehabilitation of old sewers, many of which were constructed in a variety of ovoid-like shapes. This paper presents the typical steps that are performed for pipeline rehabilitation with non-circular profiles, as well as an applied case study (a project implemented in the city of Würzburg in Germany).</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Efficiency of the construction market and need for government regulation<abstract><title style='display:none'>Abstract</title><p> For a long time in economic theory and practice, regulation is only linked to the need for state intervention in monopolistic markets, by developing uniform, simple regulatory rules to limit and control the monopoly power, the monopoly price, mergers and acquisitions between companies in the same industry and others. In recent years the prevailing opinion that government regulation is particularly necessary in oligopolistic markets where there are several leading, dominant companies that can influence the price, quantity and quality of the product offered. However, this regulatory policy should not apply to common rules and taking into account the specifics of the market/industry, market structure (concentration level) of the various market segments and the relevant economic activity. The aim of the study: 1) Evaluation of the efficiency of the construction market, 2) Demonstrate the need for government intervention, 3) Guidelines for the implementation of the regulatory function of the government.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Roof structures. Comparisons between traditional roof structures and industrialized ones<abstract><title style='display:none'>Abstract</title><p> Roofs with one or more slopes, represent an important part of a construction, having a double role: a role of resistance together with the entire constructive system and a protective role both for the other components of the constructive system and for the optimal unfolding of the various functions. The durability and the fulfillment of the mechanical requirements depend equally on the material used, design quality and execution quality. Industrialized roof structures can be a solution, under the current conditions, to meet these requirements. This article compares the traditional roof structures and the industrialized one.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Radioactivity of the lower sector of Danube River and the Black Sea coastal zone in relation to some hydrological characteristics<abstract><title style='display:none'>Abstract</title><p> On ecosystems, the radioactive material can have several consequences: the mechanisms of self-regulation of biocoenosis are affected; the interactions and composition of flora and fauna in biocoenosis are modified etc., and on humans, radioactive material presents a major risk through external exposure and internal exposure to radiation. On the other hand, floods and droughts, among others, can have the effect that they can act as a support for radionuclides. The existence of risks of radioactive and chemical pollution on the lower course of the Danube, in the Black Sea Danube spill area as well as in the Black Sea coastal area, where a number of complex processes occur, determined the study of the radiochemical processes taking place in these areas. The paper addresses the following issues: radiation risk and nuclear risk, general hydrological characteristics, radioactivity of the Lower Danube water and coastal zone of the Black Sea, radioactivity of the Lower Danube sediments and coastal zone of the Black Sea, modeling of radiochemical processes.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Flash floods simulation in a small drainage basin using HEC-RAS hydraulic model<abstract><title style='display:none'>Abstract</title><p> In recent years, climate conditions has caused extreme hydrological phenomena like flash floods that lead to significant material losses and impact on the environment in Dobrogea Region, Romania. In this context the needs for an integrated and sustainable approach to flash flood risk management even in small drainage basins are necessary, in order to reduce the the potential damages of flash floods in the future. In this study the hydraulic models Hec-Ras and HecGeo-Ras were used in order to simulate the behaviour of the environment at the pressure of the flashfloods in a small drainage basin. The results were validated using the measurements undertaken after the flash-flood event recorded in October, 13th, 2015 as well as the data provided by the Corbu gauging station along time.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Application of thermal discomfort indices for the coastal zone of Black Sea, in Dobrogea Region<abstract><title style='display:none'>Abstract</title><p> The main goal of this paper is to establish the thermal comfort or thermal discomfort conditions for the coastal zone of Black Sea, in Dobrogea region (Romania). In the last century there have been many efforts to assess the degree of thermal discomfort and heat stress for different types of climates and taking into account as many climate variables. The thermal discomfort is difficult to be quantified because it is necessary to consider a range of environmental and human factors to decide what makes a person to feel thermal comfortable. This article is divided into three sections. First section presents the indices used in determining thermal discomfort, in the second section are presented: the main climatic characteristics of the Dobrogea region and the data and methods used in determining thermal discomfort indices. Section three is dedicated to results and discussion.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Reabilitation of a wastewater treatment plant – possible environment impact<abstract><title style='display:none'>Abstract</title><p> Romania, has declared, by the Governmental Decision nr.352/2005, all its territory as a sensitive area. This implies that, for all urban agglomerations larger than 10.000 population equivalent waste water treatment plants (WWTP) with nutrient removal must be built or upgraded. This paper presents the results regarding the possible environmental impacts expected from the project for construction of waste water treatment plant in the City of Vaslui, with main focus on surface water. This research study includes assessment methodology, project description regarding the rehabilitation and extension of the Vaslui waste water treatment plant, data related to water resources, impact assessment on water and appropriate mitigation measures. The assessment of the impacts has been performed for the construction and operational phase of the wastewater treatment plant. The construction phase was subdivided into several phases, while in the operational phase the impacts are analyzed following the line for treatment of the wastewater and effluent production, the line for sludge production and drying process, sludge disposal in safety conditions considering the provisions of 86/278/EEC Directive and the line for biogas utilization.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00The impact of maritime spatial planning on the development of the Black Sea<abstract><title style='display:none'>Abstract</title><p>Abstract In order to implement Directive 2014/89/EU of the European Parliament and of the Council establishing a framework for Maritime Spatial Planning, Romania and Bulgaria are carrying out the “Maritime Spatial Planning for the Black Sea - the Romanian - Bulgarian cross-border area” project (MARSPLAN-BS). The impact of the implementation of the Maritime Spatial Planning (MSP) project on the Black Sea coast on the development of the coastal area requires an analysis that is carried out by the authors in this paper.</p></abstract>ARTICLE2018-05-17T00:00:00.000+00:00Systems to Protect and Improve the Behavior of Buildings Located In Macroporous Lands Susceptible to Wetting<p>Macroporous lands sensitive to wetting represent a category of sites with high vulnerability during construction exploitation. In this regard an effective measure is the protective shielding measures against the main factors influencing its behavior. The paper deals with a complex case study by both its importance functions and the fact that the objective analyzed is a part of historical monuments of particular value to the local community, namely the water tower in Braila Public Garden - România.</p>ARTICLE2020-12-31T00:00:00.000+00:00Role of the Construction Market and the Firm for Sustainable Development and Sustainable Construction<p>Sustainable development and sustainable construction present every firm with new challenges. The concept of sustainability is the new driving force for the firm and decision making, which are part of the overall sustainable strategy. The implementation of this strategy is a factor for creating, offering and realizing additional economic, social and environmental value for the client, stakeholders and society as a whole, and building competitive advantages. Detailed knowledge of the principles and requirements for sustainability and the necessary changes at the market and company level are mandatory for every construction manager. The main goal of the research is 1) analysis of the role of the construction market and the firm for sustainable development and sustainable construction, 2) outlining the necessary changes in the organization and management of the firm in order to create sustainable construction firm and development sustainable construction.</p>ARTICLE2020-12-31T00:00:00.000+00:00Effects of Shear Lag in Steel Box Girders of a Crane Runway<p>The term of shear lag is related to the discrepancies between the approximate theory of the bending of beams and their real behaviour. It refers to the increases of the bending stresses near the flange-to-web junctions and the corresponding decreases in the flange stresses away from these junctions. In the case of wide flanges of plated structures, shear lag caused by shear strains, which are neglected in the conventional theory, may be taken into account by a reduced flange width concentrated along the webs of the steel girders. In EN 1993-1-5, the concept of taking shear lag into account is based on effective width of the flange which is defined in order to have the same total normal force in the gross flange subjected to the real transverse stress distribution as the effective flange subjected to a uniform stress equal to the maximum stress of the real transverse distribution. Some aspects concerning the shear lag phenomenon and a working example for a box girder of a heavy crane runway to illustrate the determination of the shear lag effect are also presented.</p>ARTICLE2020-12-31T00:00:00.000+00:00Retained Water in the Commune of Gogounou in Benin: Inventory, Characterization and Management Mode<p>The present work was carried out with the aim of knowing the characteristics and the management made of the agropastoral dams of the commune of Gogounou which are of a great utility for the local populations. To do this, twenty (20) dams were chosen according to the strategic interest that they present for the population, that is to say a polling rate of 87% on all the dams of the municipality. An inventory of the dams was made according to quantitative and qualitative indicators. The results showed the existence of (04) groups of dams according to the technical characteristics and some qualitative variables. The parameters that lead to the degradation of these dams are often related to the age and type of dam and the place of installation. Groups (2 and 4) are agropastoral dams (100%) and more than half of the dams are on flood sites. Results have also shown that there are management committees around all the dams in the commune of Gogounou, but which are mostly non-functional at almost 75%. Also, it has been found that the breeders are mostly transhumant and sedentary who use (100%) dams for watering animals. This cohabitation between farmers and pastoralists does not occur without major conflicts, in particular, that of land whose settlement is generally peaceful. In short, the management of the dams in the commune of Gogounou is a real challenge to be met for a better development, both economically and socially to guarantee the prosperity of the actors and prepare them to adapt to the vagaries of the climate future.</p>ARTICLE2020-12-31T00:00:00.000+00:00Sediment thickness in the Bay of Bengal and Andaman Sea compared with topography and geophysical settings by GMT<p>The study presents an analysis of the sediment thickness compared with bathymetric and geophysical settings in the Bay of Bengal and Andaman Sea, Indian Ocean. It uses a combination of the high-resolution data: topographic GEBCO, satellite and marine gravity anomalies, EGM2008 geoid and GlobSed to visualize the correlation between relief, gravity and trends in continent-ocean sediment transport. The results include thematic maps and 3D model showing increased sediment thickness in the Bengal Fan (8,0 to 8,2 km) in NE direction with maximum in Ganges Fan (16,2 km), and southward decrease in the Andaman Sea from Irrawaddy river mouth (6-7 km) to the Strait of Malacca (1-2 km). All maps and 3D model have been plotted by Generic Mapping Tools (GMT) cartographic scripting toolset version 6.0.0.</p>ARTICLE2020-12-31T00:00:00.000+00:00Flood Risk Assessment Based on Flood Hazard and Vulnerability Indexes<p>Within this paper, a methodology for assessing the flood risk was developed by extracting the essential factors that favor the generation of flood risk. These factors, that had a sufficient number of data for a proper comparative analysis, are: potentially affected population based on population density, total agricultural area, total built-up area and the historical maximum amount of precipitation recorded in 24 hours. The flood risk assessment is presented in the form of indices calculation for all these factors and maps generated which representing the results of the calculation of the above-mentioned factors and the results of the flood risk index calculation.</p>ARTICLE2020-12-31T00:00:00.000+00:00Research on Improving the Welding Behaviour of Stainless Steels in the Field of Welded Constructions by Using Mechanical Vibrations<p>This paper presents a research that has been done on two types of stainless steels, one of Spanish origin and the other of Romanian origin. Both Spanish and Romanian stainless steels have been subjected to several tests, regarding the influence of vibrations on their mechanical properties and their welding behavior. The samples were made of welded stainless steels. They were subjected to a thermal hardening treatment at a temperature of 950 degrees, with a holding time of 4 hours in the presence of mechanical vibrations. Then comparative tests were performed on both stainless steels at: hardness, tensile test, resilience, microstructural analysis and determination of the longitudinal modulus of elasticity. The research has shown a reduction of the thermo-mechanically influenced area, which contributes to the achievement of a high quality welded joints.</p>ARTICLE2020-12-31T00:00:00.000+00:00Behaviour Analysis of a Cross-Girder to Tie-Girder Connection at a Road Bridge Structure<p>This paper presents several theoretical issues regarding the behaviour and calculus of the connections made with end plates and bolts, including the cover plate for the tensile stress flange. An example for calculating the hybrid connection solution is also provided, when end plates are joined together with bolts and an additional cover plate over the joint area, at the elongated flange of the girder, a solution applied for a bridge for which the feasibility study was performed.</p>ARTICLE2020-12-31T00:00:00.000+00:00Role of the Government for Development of Sustainable Construction<p>In the last years questions related to sustainable development are particularly relevant. The construction market is usually identified as the first sector to face serious problems and requires special attention in implementing the idea. The main reasons for this assessment lie in the specifics of construction as an economic activity, the specifics of the construction product, the construction process, the specifics of organization and management of the construction company and the strong economic, social and environmental effect. The purpose of the proposed study is: 1) analysis of the problem of sustainability of the construction market, 2) the role and influence of the government for the development of sustainable construction.</p>ARTICLE2020-12-31T00:00:00.000+00:00Researches on the Welding Behaviour of Two Brands of High-Alloy and High-Efficiency Electrodes Used to Charge High Wear Parts<p>The research performed and presented in this paper, aims to verify the welding behavior of electrodes developed experimentally, as well as the possibility of their use in production. A group of two electrodes produced by Bohler Company, Gridur 24 and B.M.N were taken as reference, in order to compare them in terms of the mechanical properties of the deposited metal, with the experimentally developed electrodes EICr12Fe and EIMn13SiFe. They were made determinations of the chemical composition of the deposited metal with the two types of electrodes, measurements regarding the hardness of the metal deposited, comparative determinations of the structure of the weld deposit, and of the welding penetration, determinations of the deposition yield and verification of the welding behavior.</p>ARTICLE2020-12-31T00:00:00.000+00:00Installation for Producing Mechanical Vibrations used in the Finishing of the Welded Joints Structure<p>The paper presents a constructive version of a mechanical vibration generator designed to be used at stress relieving of welded joints. This installation can be used on all brands of steels and welded joints, whether they have magnetic properties or not. In the generator construction a DC motor was used, in order to be able to adjust the speed more easily. The speed adjustment is made with a potentiometer, and the speed measurement is made with a tachometer. The tachometer measures the speeds based on the pulses given by a four-pointed cam rotating between the plates of a capacitor. The vibration system also contains a piezoelectric accelerograph, which is attached to the welded part subjected to vibration, in order to measure the level of vibration and the parameters of the vibration wave.</p>ARTICLE2020-12-31T00:00:00.000+00:00en-us-1