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International Conference CIBv2020 Civil Engineering and Building Services, Edited by, FOREWORD, Honorary Committee, International academic scientific committee, Organizing committee list of titles are available in this pdf

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● Type of peer review: Single-blind / Double-blind / Triple-blind / Open / Other (please describe)

The peer review process was a single blind review. Each manuscript was reviewed by at least two reviewers.

● Conference submission management system: The submission management was an on website uploading type one. Each abstract was uploaded on the conference website and the papers were sent directly via conference e-mail.

● Number of submissions received: 76

● Number of submissions sent for review: 54

● Number of submissions accepted: 47

● Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 61.8

● Average number of reviews per paper: 2

● Total number of reviewers involved: 54

● Any additional info on review process: during the review process, all papers were checked for compliance with the topic of the conference, acceptable English language and the quality of images/figures, tables, equations and general aspect.

The review process took into account the following key points:

- Each reviewer was asked to fill in a paper review form containing: an overall evaluation (the manuscript was assessed by grade), an evaluation in which the reviewer was asked to grade the paper following "Contribution to existing knowledge", "Quality of the presentation", "Scientific soundness", "If the conclusions are supported by data" and "Relevance to the literature review" and a detailed evaluation in which the reviewer was asked to fill the "strengths" and the "weaknesses" of the paper. Additional comments to the author(s) and to the editors (optional) were implied. The grades were from 1 – Poor to 5 – Excellent.

- The criterion for accepting the paper was to have a minimum grade 2 from at least two reviewers. After the receiving of paper reviews, each author was asked to revised the manuscript according with the reviewer's (and, where was the case, editor's) comments.

- For each revised paper, editors checked the respecting of the reviewer's remarks and, where was the case, asked a second opinion from the reviewer(s).

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The paper presents the researches, prototype laboratory equipment and technologies developed by the authors for the plasma conversion of fiberglass waste into useful materials for building industry. The aim was to increase the energy efficiency of conversion processes and to obtain technologies and materials with better proprieties for civil engineering appliances and reduced impact on the environment.

The article presents a comparison of the values of the soil deformability characteristics obtained at different densities of the sand base based on the results of laboratory tests³ and the results of computer modeling, using the software systems "ANSYS" and "Plaxis 3D".It was found that for loose sandy soils, at densities of 1.48 – 1.53 g/cm³, close to experimental values of the deformation modulus were obtained using a three-dimensional finite-element model of polylinear isotropic hardening "PLAS (Miso)," in the program "ANSYS." For average density bases at ρ = 1.55 – 1.66 g/cm³ minimum differences between experimental and numerical values were obtained using the «Plaxis 3D» complex.

Freezing liquids into ice is a complex simulation and is called a phase transformation or phase change. Isochoric (constant volume) preservation is a new thermodynamic concept that takes advantage of an until now ignored aspect of thermodynamics, life under conditions of constant volume as opposed to the conventionally studied life conditions of constant pressure. Isochoric system are simple constant volume devices, made of steel, capable of withstanding the pressures that develop in the system, with minimal deformation. Because ice-I is less dense than water, the formation of an ice nucleus in an isochoric (constant volume) chamber will cause an increase in pressure. Traditionally, ice formation is performed in an isobaric process (constant pressure) at 1 atm, because this is our natural environment and it is most convenient experimentally. The goal of this study is to introduce the fundamental thermodynamic principles and boundary conditions of isochoric (constant volume) simulations at low temperatures. In this analysis we intend to shows that homogeneous ice nucleation can be thermodynamically improbable in an isochoric system.

The physical and mechanical properties of concrete designed to a C40 mix using 6.5 mm and 10.0 mm aggregate from Montenegro and Malta respectively were investigated. Ultrasonic pulse velocity (UPV) and compressive strength (CS) tests corroborated findings in the literature. The coarseness of aggregate was found to be of primary technological importance: CS increased with increasing aggregate size. Although UPV in all the tests was between 3.5 km/s and 4.5 km/s – that is the concrete quality was of good grade – the CS of the control cubes for the 6.5mm and 10.0mm coarse aggregate mixtures was 27 N/mm² and 39 N/mm² respectively. The homogeneity of the concrete was affected by the physical and mechanical properties of the aggregate, including its size, but its petrological texture was also a significant parameter. The petrological characteristics of the aggregate severely affected the load-bearing capacity of the concrete. These characteristics had a significant bearing on the physico-mechanical properties of the hardened concrete.

Optimising buildings and energy systems with a focus on mitigation of greenhouse gas emission is not an easy task: first, principles are necessary to be established and then the steps to be followed. Exergy efficiency can show the best issues: building envelope insulation and air tightening, low-valued energy sources, low-exergy heating and cooling systems, avoiding destructive exergy-processes like boilers burning fossil fuels, systems and grids for low-temperature heating and for high temperature cooling, renewable energy sources, daylight, and passive solar energy use supported by control strategies of building systems can contribute to a better future when considering global warming and comfort.

The main concern of the paper is the energy consumption management, in relation to the advantages and disadvantages of an intelligent building. The building sector consumes about one third of primary energy. An intelligent use of energy could have an impact on the energy consumption and cost. Energy management is the process of controlling, conserving and monitoring the energy in a building or recently in a home. With the use of sensors, all systems are connected and useful data is gathered to improve the building's efficiency. Intelligent building design is the future of building and building services sector. Enhancing energy preservation strategies and using sustainable design approaches are necessary in developing intelligent buildings. This implies a more effective approach to reaching the green goals, and it also implies financial savings. Building an intelligent building involves a larger investment, but in the long run the usual expenses will decrease. National grid energy consumption will decrease with the use of renewable energy sources, such as solar or wind energy, if the energy is produced on site. In order to make a difference in the climate change, intelligent buildings depend on the non-fossil sources, which will affect the energy usage. Furthermore, an intelligent building will increase the comfort and productivity of its occupants, for either a workspace or a home.

Renewable energy sources (wind energy, solar energy, energy hydropower, ocean energy, geothermal energy, biomass and biofuels) are alternatives to conventional fuels in the greenhouse gases emissions reduction process. Because of the EU legislation support, the renewable energy sources have evolved significantly in recent years and in 2009 EU set a target of 20% energy consumption comes from renewable energy sources by 2020. In 2018, the target has been set for 32% of energy consumption from renewable energy sources by 2030. There is currently a debate on the policy framework future for the period after 2030. Greenhouse gas emissions is considered a serious threat regarding climate change, with potentially disastrous effects on humanity. The use renewable energy sources (RES), together with improved energy efficiency, can contribute to the reduction of energy consumption, the reduction of greenhouse gas emissions and, consequently, to prevent dangerous climate change. The potential of biomass, solar, hydro, wind and geothermal energy is very important, especially in recent years, due to financial support mechanisms such as green certificates, which in many European countries helped this sector to developed progressively.

The article presents the results of processing a number of compositions of composite materials sustained under cyclic temperature changes, as well as changes in humidity and positive temperatures. A method is proposed for determining the optimal composition of materials, taking into account changes in such characteristics as hardness, modulus of deformation of the material and the elastic modulus of the material during exposure.

The expediency of quantitative analysis of safety and comfort of the spatial environment when creating master plans of cities was shown by the authors. Predictable thermal comfort should be considered here as one of the significant indicators of the environmental safety of the routes from places of residence to socially significant facilities and recreational zones. It is suggested to use thermal indexes adapted for the conditions of open urban spaces to consider the influence of climatic variables totality on the person's thermal sensation. The physiologically effective temperature (PET) is one such index. This model takes visceral temperature, perspiration rate, the moisture of the skin, and on the other hand the meteorological parameters, including the influence of urban area conditions on them. Criteria values of PET for the middle zone of Russia are determined on the basis of bioclimatic estimation of the territory according to air temperature, cloudiness and wind speed. The authors determined experimentally the parameters of the urban microclimate.

Ground source heat pumps (GSHP) are the most efficient heat pump systems currently in use for residential sector today. Although these systems outperform all other heat pump systems when considering the energy source, the installation costs represent an ongoing issue. For the market to increase in this area, multi-criteria optimization for the ground heat exchanger (GHE) is the main research topic today. The main objective of this study is to search ways to optimize the horizontal ground heat exchanger focusing on two distinct viewpoints: physical and energetic optimization. To achieve this goal, the entropy generation number and the coefficient of performance based on several configuration are studied. Using the Pareto optimal set obtained from two objectives provides useful information about the design optimization. In comparison with traditional single objective optimization, multi-criteria optimization avoids cost increase when regarding only the performance or performance decrease when regarding only the cost. The results indicate that the use of a cheaper heat source such as solar panels to mitigate the energy needed for peak loads during the heating and cooling systems can reduce the horizontal ground heat exchanger size and therefore the installation cost. A hybrid solar assisted ground source heat pump system, using more than one renewable energy source, shows a much higher flexibility for residential purposes than a heat pump system that uses only one renewable energy source.

Ground heat exchangers represent the barrier between installing a ground source heat pump (GSHP) or a heat pump that use another source as water or air. While the vertical ground heat exchangers (VGHE) yield better results than horizontal ground heat exchangers (HGHE), the installation cost is higher than HGHE. Although, HGHE installation cost is a lot more affordable for residential use, it has the disadvantage of requiring a large installation area and lower efficiency than VGHE due to the temperature variation at the surface of the ground throughout the year. This study focuses on investigating possible use of the energy that is lost through the ground from basements in general, to help the heat pump when the HGHE is installed in the proximity of the basement. In order to achieve concluding results, an experiment was conducted at the University of Transilvania from Braşov, at the Faculty of Civil Engineering. In the experiment the HGHE was installed next to the basement exterior wall. In addition, a CFD numerical study was conducted. Firstly, to verify the experimental measurements and secondly, to obtain results with different working parameters. The results indicate that the thermal insulation degree of the basement wall and floor is an important parameter when considering heat loss into the ground. Likewise, the thermal state of the basement, heated or unheated, contributes considerably to the final results. Consequently, positioning the HGHE in the proximity of basements can represent an energetic optimization, especially when the basement is heated and it isn't thermal insulated, as can be the case for an existing building.

The last decade is characterized by an increase in the occurrence of flash floods, fact which is confirmed by the worldwide endeavors undertaken by the WMO (World Meteorological Association) which initiated the signing of a series of memorandums for collaboration with other worldwide institutions meant to lead to the elaboration and implementing of a complex flash flood warning system. The aim of this paper is to analyze the level of implementation of said system in Europe and Romania and the analysis of the flash flood occurrence, specifically in the Dobrogea region of Romania.

Construction represents an important branch of the Romanian economy. The construction branch must be characterized by flexibility and diversity, attributes that favor change, through generation, continuous development and rapid transposition into practice of new ideas. The demands of society are becoming more and more severe throughout the all countries of the world. Expectations and needs are becoming increasingly explicit for issues such as: health and safety of the place where we live or work environmental protection, operational safety.

Flood frequency analysis is the most important statistical technique in understanding the nature and magnitude of high discharge in a river. This technique is used for establishing a relationship between flood magnitude and frequency of occurrence (return period). This study performs the flood frequency analysis of Casimcea river. The Casimcea catchment is located in the Dobrogea-Littoral basin of south-eastern Romania, and covers parts of two counties, Tulcea and Constanta. The main river of Casimcea catchment flows into the Tasaul lake and has two main tributaries (Ramnic and Cartal). In this study, Log-Normal, Log-Pearson Type III and Gumbel probability distributions have been applied on maximum discharge time series data of four hydrological stations, Casimcea and Cheia on Casimcea River and Pantelimonu on its main tributaries Ramnic and Cartal. For this study have been used the annual maximum series data spreading from 29 to 52 years. The frequency analysis will be performed with Hydrognomon. open-source software for the analysis of hydrological data. Hydrognomon is free software licensed under the General Public License (GPLv3).

The paper provides a research on the energy performance of current marketed building materials used for household construction in eastern Morocco. Firstly, the characterization of the thermophysical properties of commonly used building materials (cement, plaster, hollow bricks and insulation boards) was carried out using the Hot Disk method. A local building material database of eastern Morocco region was developed. It was found that the thermal conductivity of the most affordable insulation boards was of 0.03 W/mK, while the thermal conductivity of cement-based products ranged from 0.65 to 0.7 W/mK. The experimental results show that the Moroccan market of building materials cannot participate in promoting eco-construction and designing efficient lightweight building envelopes at local level. Therefore, a strong focus on the development of local low-cost insulation materials for building applications are needed. The numerical building performance analysis shows that available building practices are only efficient for passive heating. Further studied on passive cooling techniques are greatly required for designing low energy buildings in Morocco.

Modern building techniques, materials and methods open possibilities for rediscovery and new applications of organic and more environmentally friendly solutions in multiple sectors of the building industry. As more scientists and engineers are looking at sustainable resources, the possibilities for managing the potential weaknesses of making more environmentally friendly building and product materials are bringing new materials and methods to the market at a rapid pace. The new biodegradable solutions are looking into natural fibres, or crops and wood. Hemp-based materials are already well re-established in multiple environmentally friendly products in the building industry. Hemp-lime, hemp insulation or hemp plastics are materials with low carbon footprint which are successfully being used in construction, replacing successfully non-renewable building materials. In cars, the BMW i3 has for several years featured hemp and kenaf, and Hunton Nativo wood fibre insulation is another example from the building industry of how renewable climate friendly materials can easily replace non-renewable materials. This article aims to highlight some existing solutions, and possible improvements to products in the building industry.

Current urban water systems aim to ensure hydraulic and water quality parameters for all consumers connected to the water distribution network, with the highest possible efficiency. This corresponds to reduce primary energy consumption and a responsible control of drinking water sources in order to supply water to urban areas. Most of the time, a low efficiency of water supply systems is due to the following factors: inefficient operation, poor maintenance, incorrect sizing and unmetered water consumption. This article analyzes the efficiency of the solutions applied in the pumping station as a component part of the water supply systems. The case study focuses on the operation of pumps in water supply systems and presents the analysis of the relationship between water consumption and electricity of a pumping group in an urban water supply system. This paper is a first step in order to obtain global parameters for energy optimization of the urban water system.

This paper presents a modern system for conversion with plasma with hydrogen of industrial liquid waste which has implemented a control system through thermoregulatory with PID control laws. Modeling and simulation of thermochemical plasma process performed using specialized software Matlab & Simulink, Ansys allows the optimum control of the temperatures and chemical reactions of the plasma reactor on hydrogen, allowing the conversion of hazardous industrial liquid waste into electrical and thermal energy and useful raw materials that can be reused in the production process.

In Romania, the risk of a fire occurring within a building is determined in a very conservative manner, as a function of the building occupancy type and the thermal load contained within each enclosure. The result is a qualitative expression of low, moderate or high fire risk. On the other hand, the fire is a serious hazard which has to be taken into account within the decision-making process by any organisation for the elaboration of their risk assessments and the risk management strategies. Nevertheless, the one carrying out a fire risk assessment has a various range of methods and techniques to apply, [1, 2] since the legislation does not specifically require a certain approach. This article is an example study of the application of Bayesian statistics to determine the probability of a fire occurring within an office building, due to an electrical fault.

When the land available for a construction is in slope, with a high degree, there can be a series of problems related to geotechnical data and execution difficulties, considering the foundations and the structure itself. The grade of difficulty is considerably increased when an extension or attic is intended to be design and build. The paper is presenting some considerations to this problem, taken into account a study case – extension of an existing structure for a family house.

The National Network for the Seismic Monitoring and Protection of Building Stock is a key infrastructure of the National Institute for Research and Development in Construction, Urban Planning and Sustainable Spatial Development "URBAN-INCERC" in Romania. This infrastructure includes at present, among other research facilities, a strong-motion network of 64 permanent seismic stations, to which other temporary stations are added for various short-term vibration monitoring projects. Since its establishment in 1967, the seismic network has played an essential role in recording the earthquakes that affect Romania. Today, the seismic stations are distributed all over the country, according to its characteristic seismicity patterns. Most of them use state-of-the-art recording and communication equipment, being permanently connected online to the Data Center in Bucharest. The management of the network implies conducting a complex set of activities, centered on the recording, processing, analysis and interpretation of natural- and human-induced vibrations. All of these are seconded, in parallel, by various maintenance, reporting, logging, communication and dissemination tasks. The logistic and financial management also plays an important role. A rational and efficient administration of the seismic network cannot be acquired without a rigorous organization of data flows pertaining to the various activities performed. The paper provides insights from the organization of the network, highlighting the intercorrelation between the hierarchical levels of its functionality and the logical course of operation. A brief review of the challenges and solutions gradually developed and implemented by the members of the network team, in order to provide the required functionality, is presented.

Incorporating electronic waste (E-waste) in a new asphalt mixture is a subjected connected to the recycling process of PCB (Printed Circuit Boards), in which PCB waste is turned into a powder. The aim of the paper is to present the performance of the new asphalt pavement obtained by using PCB waste to substitute lime filler in a share of 100%. First, laboratory analyses are performed to determine the composition of PCB. Then, the feasibility of using PCB waste in the asphalt pavement industry is analysed in a series of laboratory investigations conducted on asphalt concrete BA16 rul 50/70 (AC16) that is a standard asphalt mixture in Romania. The following tests are performed on the new material: cyclic compression-dynamic flow, rutting test, and Marshall Stability and flow. The conclusion after the first experimental stage of this research is that the mixture containing PCB is softer than the control/witness mixture containing lime filler. Further investigations regarding the use of E-waste in road asphalt pavements will be conducted to find a way to reduce the use of new raw materials in the road construction industry.

Joints made out of tubular steel members are often used in industrial constructions, like offshore, trusses or tree-shaped columns. The joint area is the weakest point in a truss structure. Beside the normal static behaviour many non-linearities due to the geometry or to the welding process have to be taken into account. Steel hollow sections are often used. Much research was made on welded nodes so far. To increase the resistance of a joint it is an option to vary the material choice. Many variations were tested in the past. It is possible to change the overall material of a joint or using composite structures, like a concrete filled column. Or the steel of the welding line can get an additional material component. Another aspect is to reinforce the joint for example by a stiffened ring. In this paper a state-of-the-art review of the influence of different materials to the resistance of welded nodes is given.

The present paper is focused on the assessment of industrial buildings from their thermal and energy performance perspective, driven by the need to reduce energy consumption and CO2 emissions on a worldwide level. A state of the art will be elaborated regarding the environmental impact of buildings that led to an increased pressure on a more energy efficient design. The focus will afterwards turn on the constructive solutions of industrial buildings for a better understanding of their elements and materials used. Aspects regarding the national and international stock of industrial and logistics spaces, demand, price range and future evolution of this sector, are also presented. Description and comparison is conducted on the building envelope thermal performance and its impact on the energy performance of buildings. Several conclusions will be drawn based on the obtained energy indexes and future research paths will be suggested.

In the soundness evaluation method based on waveform analysis in time domain, the response waveforms that are measured while the target is in sound condition is indispensable. Therefore, it is expected that this method is for the evaluation of precast concrete products because the state of the products is almost identical and it is able to measure the response waveforms before using the products. On the other hand, although there are difficulties to apply this method for the evaluation of the existing structures because the response waveform is not measured before using, it is expected that this method can be applied to the evaluation of the existing structures by making the response waveform on the basis of the numerical simulation. The computational conditions should be set properly based on the actual measurement conditions for the numerical simulation. Among the computational conditions, the input frequency is determined based on the diameter of the steel ball and contact time if the excitation is given by making an impact with the steel ball by using the theory proposed by Sansalone et al. However, Kubo et al. reported that the measured contact time is different from the theoretical value and the difference reaches maximum twice. The influence of the difference would not be negligible for the soundness evaluation and should be considered carefully to perform the soundness evaluation accurately. Therefore, in this study, the response waveforms are computed on a numerical model with excitations of various input frequencies, and the influence of the input frequency to the response waveform is discussed by comparing the computed response waveforms.

The axial compressive load test and finite element simulation are made to study the mechanical properties of aircraft stiffened composite panel. Firstly, the numerical simulation model of composite stiffened panel structure is constructed, the accuracy and feasibility of the simulation model are verified by calculating the value of MAC (Modal Assurance Criterion) between the computational free modal and experimental free modal. Then, the nonlinear post-buckling numerical simulation is carried out to extract the buckling load, the post-buckling load path and the failure load. Then, the axial compression test of the panel structure is carried out by the testing machine, and the load-displacement curve and the load-strain curve of the loading position are obtained. Finally, the correctness of the analysis method is proved by comparing the numerical simulation value with the experimental analysis value. The experimental research method of the mechanical properties of the composite stiffened panel under axial load is explored, which can be used as a reference for the study of the bearing capacity of the stiffened panel.

This paper reviews a series of experimental tests programmes undertaken at BRE in the UK on the performance in fire of high strength concrete with a particular focus on mix design to assess the effects of spalling. The experiments include a series of fire tests on reinforced and unreinforced concrete columns and tunnel linings. The paper will provide information on the parameters that lead to explosive spalling of tunnel linings in a fire situation and on the measures available to mitigate this hazard.

One of the most important environmental problems of the big urban areas is represented by the large volume of waste resulted from different human activities. In the last decades, different technologies have been developed to resolve this significant issue, and the most representative is the conversion of municipal solid waste (MSW) in different types of by-products. The first part of this paper presents the current state of plasma conversion technology that can be used for processing waste, and also, its potential in the construction sector which could be taken advantage of the by-products (syngas and slag) resulted from the plasma gasification of municipal solid waste (MSW), to enhance energy-efficiency in this domain. In the second part of the paper, there are analyzed different technologies for managing and processing municipal solid waste (MSW), which can be used nowadays, and the parameters, related to the costs, the period of use, the energy consumption and the environmental impact. All these aspects are compared with those of plasma conversion technology. The plasma conversion system can be commercialized successfully, and its costs can be reduced by generating income in the form of by-products and added-value in producing performant products in a circular economy.

The present study numerically analyses the influence of physical and mechanical properties of the materials used for masonry infill panels upon the seismic response of low rise reinforced concrete frame structure. A four-storey residential building (benchmark), located in Timisoara, a moderate seismic area, has been designed according to the current Romanian design codes. Then, infill panels considered uncoupled from the frame members along their lateral and upper edges, have been added to the structure. Infill panels have been investigated in four variants, by using 2 types of masonry units (hollowed ceramic blocks and AAC), alternatively built with mortars specific for regular bed joints (G) and thin bed joints (T), for which a comparative modal response spectrum analysis has been carried out. The seismic behaviour of buildings in all these cases has been analysed in terms of peak inter-storey drifts under two limit states and of the out-of-plane strength of infill panels. The results show that the peak inter-storey drifts reductions compared to the benchmark structure are up to 59% at SLS, and 61% at ULS. Regarding the out-of-plane behaviour of the infill panels it was noted that safety verification is fulfilled only for one of the abovementioned cases. As a final remark, the results obtained in this study highlight the importance of physical and mechanical properties of the masonry infill panels in the assessments of seismic response of frame structure buildings.

The seismic performances of R.C. frame structures were determined in terms of inter-storey drifts at two limit states, internal forces and moments (axial forces and bending moments), and the in-plane behaviour of infills. A nonlinear static analysis (pushover) was carried out in order to assess the seismic performance of buildings, to identify the expected plastic mechanisms and to plot the capacity curves. In pushover analysis, the vertical distribution of the monotonically increasing horizontal loads, was performed according to the first mode pattern. The nonlinear behaviour of structural members for pushover analysis was modelled by using the lumped plasticity, from where it derives that the potential plastic hinges were situated at the beams ends (which yield due to the bending moment), at the top and bottom of the columns at any storey (which yield based on the interaction of axial force and bending moment) and in the struts (which yield due to the axial force).

The flow of viscoelastic fluid in the gap between the impeller disc and the pump wall for laminar flow mode is considered. Waste water sludge (WWS) was used as a working fluid. Its flow is described by viscoplastic fluid model. The results of theoretical and experimental studies of disk friction at WWS are presented and formulas are proposed for calculation of disk friction power between wheel disks and pump body.

Building of an experimental slope protection system on Căpuş river, near Cluj presented the opportunity of in situ testing of stabilized soils. Different hydraulic binder was used on each side of the river, so this testing series provided valuable data about deformability properties of the encountered soil types. There are some deformability parameters used in Romania which were "imported" at the specific request of foreign investors. The strain modulus, E_v, is a parameter expressing the deformation characteristics of a soil and is calculated taking values from the load-settlement curve obtained from the first and second loading cycle, on a static plate load test. In earthworks, the dynamic plate load test using the Light Falling Weight Deflectometer may be used for testing load-bearing capacity as an alternative to the static plate load test which provides the strain modulus, E_v parameter. Dynamic modulus of deformation E_vd is a parameter for the deformability of soil under a defined, vertical impact load with the impact duration. Its value is being calculated with the maximum settlement of the load plate. None of these methods made way into official Romanian standardisation, the E_vd is subject of a technical agreement, which also contains the correlation of it with E_v. Conducting both static and dynamic loading tests enabled the verification of validity of relation between strain modulus and dynamic modulus.

In order to investigate the progressive failure of soil-structures, non-destructive inspections have been applied in recent. Use of Acoustic Emission (AE), the elastic wave which is generated by the occurrence of cracks, is attractive in this field to detail the progressive failure if the measurement is conducted with sufficiently small time interval. Although this technique potentially detects the cracks clearly, conventional methods of AE source localization consider that elastic wave velocity distribution is homogenous, and there are the limitations of its application due to the diffraction and the refraction of elastic wave if the heterogeneity of the elastic wave velocity distribution is not negligible. In this study, AE-Tomography (AET), which performs the identification elastic wave velocity distribution and the localization of AE sources with consideration of the diffraction and the refraction of elastic wave, is validated about the performance of the identification of the elastic wave velocity distribution and the AE sources localizations on numerical tests and model tests. Artificial AE events are generated in the soil specimen that have some parts of different relative density and validation of AET is conducted by using the arrival times of the artificial AE. According to the results of the validation, it is suggested that AET identifies elastic wave velocity distributions and AE source locations adequately on the heterogeneous elastic wave velocity distributions.

In this study, to consider a method for detecting the sediment portion of avalanches containing sediment using microwave Doppler sensors, we confirmed whether the signal processing obtained by the sensors can differentiate the objects. Since microwaves in this frequency band are not easily affected by rain and snowfall, these are being developed for use in dashboard camera and other applications. However, it is necessary to understand the attenuation of the microwave for the snow in order to apply this technology to detect the sediment in the avalanche. It is also necessary to know the rate of reflection of microwaves from the snow and sand. Therefore, it is necessary to verify whether the reflection of the microwave from the sediment is correctly measured or not. In this report, we discuss the results of the verification to see if the distance between the sensor and the object, which is known in advance, can be detected correctly.

The housing and utilities system is extremely energy-intensive and currently impedes the implementation of energy efficiency policies. In this regard, the development of science-based technology for environmentally friendly resource-saving consumption of compressed natural gas, as a source of thermal energy, is becoming relevant. The article describes the technical solution for using the energy of compressed natural gas as a source of thermal energy, which consists in using a vortex heat exchanger in the heating system of a gas control station, which allows you to generate thermal energy due to technologically unused energy, which is the pressure drop between high and medium gas pipelines as well as medium and low pressure natural gas. This technical solution is aimed at reducing energy costs and ensuring environmental safety when using compressed natural gas as a source of thermal energy. To determine the possibility of practical use of this technical solution in the production room for installing gas control equipment, an analytical expression of the temperature of the wet gas mixture after the process of condensate-evaporative heat and mass transfer in a vortex heat exchanger has been obtained, which allows us to predict the parameters of the coolant in the heating system of the production room.

The paper develops a new concept, relatively unique in approaching the concept of rehabilitation of the peasant house at the beginning of the XXI century, namely the traditional architecture of the Danube Delta as a system of integrated research, preservation of cultural and historical values. As it is known, the Vernacular Heritage Charter, ratified in 1999 in Mexico, draws attention to the fact that vernacular architecture around the world is valuable and requires protection, positive attitude in preserving, preserving and transmitting technologies, materials, architecture combined with authentic elements can even unique. This valuable built fund is increasingly subject to the pressures generated by urbanization, globalization (a phenomenon that affects local specificity) and lack of information or interest. The vernacular architecture of the Delta area was executed empirically, within the community using local materials, techniques and traditional crafts is what the Austrian American architect Bernard Rudofsky called it, in the title of his 1964 book, "Architecture without architects". The heritage reflected in the built environment of the villages in the Delta belongs to a type of vernacular architecture, and, of course, shares the general characteristics of the genre: a close communion with the natural landscape and the society in which it was "born". If we talk about contemporary ideology in architecture, in the context of very present discourses on sustainable development and sustainability (in absolutely all areas). The paper presents two approaches; high-tech, which supports the use of modern materials and advanced technology in construction and the low-tech approach, which aims at methods and techniques with low impact on the environment. The authors detail the concept of restoration corresponding to traditional materials and technologies.

Solutions that are integrating different modern techniques related to a new or an existing road, using non-destructive test brings several advantages which the content of the article highlights. Comparing the current method used in the road technique AND 540 and the aerial scanning techniques, the main element that stands out is the speed of accomplishing an ample work which consists in the 3D processing much faster and more accurately. The article presents a short current stage of these applications in the field of civil engineering. Creating 3D surfaces that it compares with what it was initially and also processing registered the deformations and displacements. A case study of a road sector is also presented to highlight everything that this technique brings.

This article brings forward a solution for compensating the reactive power of the railway electrical traction system. Using the V-characteristics of the synchronous machine, reactive power can be produced or absorbed from the power supply network, keeping the power factor at a value as close to 1 as possible. Given that the load consumed by the railway electrical traction system is variable, it is necessary to be able to promptly correct the power factor. The SCADA system will change the synchronous machine's operating characteristics relative as a function of the angle between the voltage and the current that are set at a given time by the consumers (electrical locomotives) passing through the railway section. By compensating the reactive power, the amount of active power supplied to the electrical network of the railway traction system is increased, without the need to modify the cross-section of the electrical conductors.

The promotion in Romania of the integrated conservation of the historical / archaeological sites from the urban areas represents a vector of the recognition of the importance of the archaeological patrimony, as a source of non-renewable and public development. The starting point of the article is to analyse the state of the built heritage, of the historical and natural sites in the peninsular area of Constanta in order to propose solutions for conservation / rehabilitation and their enhancement. The article will outline some principles of major importance: the need for an in-depth historical and archaeological study that precedes any intervention or enhancement, the obligation to respect with the utmost rigor the authenticity of the remains, preserving their original substance, the requirement that public accessibility not harm the quality of the sites, as the case may be, their integration in the urban structure. Case study - the wall of the Tomis fortress.

The paper aims to analyze the behavior of seismic actions of minaret – structural components characteristic of mosque. As it is known, the characteristics of this construction are governed by the slenderness and the distribution of the constituent materials by height. An important component is the most real quantification of the characteristics resistances as well as the impact of other loads in operation. The paper presents the case study – the minaret of the Carol I Mosque from Constanta, an emblematic historical monument of Constanta made by Eng. Gogu Constantinescu 110 years ago.

Construction works, as a rule, differ in complexity and hazards of works. Nowadays, cases of collapses of a formwork of the cast concrete section of a building under construction in the course of concreting became frequent. Accidents entail death of people and significant material losses. Purpose of the research: the purpose of the research is to study accidents occurred during installation of in-situ concrete floors of buildings and to reveal the typical causes of a formwork system collapse. The initial materials were the data on the causes of accidents at construction sites obtained on the basis of the analysis of statistical materials on injuries, as well as data on the identified violations of the requirements for safe work practices in capital construction and reconstruction of buildings and structures. A total of 148 accidents at construction sites from 1997 to 2019 were considered. The paper systematizes some main errors and violations of technologies committed in the course of in-situ concrete works. Typical causes common for all formwork collapses during concrete works for in-situ floor slabs installation are revealed. Among the objective causes of accidents and high injury rate in this type of construction works the following should be highlighted: the lack of method statements and construction plans; lack of supervision of the correct and safe execution of works; shortcomings in the organization of training and testing of labor protection knowledge; violation of technological regulations and safety rules.

The present paper aims at the comparative analysis of two seismic energy dissipation solutions for a steel structure in frames. We opted for non-braced frames and centrally braced frames. In the case of unbroken frames, the resistance structure consists of steel beams and columns. Potential plastic areas are formed mainly at the ends of the rulers and, to a lesser extent, in columns. Horizontal actions are mainly taken by bending the structural elements. To ensure the most efficient observance of the rigidity requirements for lateral actions, the solution of the rigid beam-column joint is required. The use of the concept of weak beam-strong column leads to the appearance of plastic joints in the beams, close to their joints with the columns. Centric braced frames can take over the horizontal actions, which are manifested in their plane, through axial forces. Energy dissipation occurs mainly by plasticizing the extended diagonals. The comparative analysis consists of highlighting the results obtained from the structural calculation with the help of a commercial automatic calculation program for the two solutions: non-braced frames and centrally braced frames. An office building with 2 levels was analyzed, located in Constanta, where the two types of the staff were provided in turn. The obtained results will be compared from the point of view of the amount of steel used, so from the economic point of view. Another comparison refers to the displacements to SLS and SLU and to the seismic energy dissipation capacity. Finally, another possible comparison refers to the over-resistance of the structural system.

The paper presents an analysis of a centralized heating system located in a city in the west-central part in Romania. We examined the last 15 years of functioning of the system from a technical and economic point of view. One of the main factors that led to the inefficiency of this system, and in the end to collapse, was the reduction of the system's thermal efficiency due to the decrease of customers over time. In conclusion, we highlighted the necessity of a periodic diagnosis of system's efficiency and a risk analysis to avoid economic problems and collapse.

Aiming at the copper screw female parts of the rock drill friction pair that are made of tin bronze and easy to wear, the material, hardness, the metallographic structure and other comparative studies have conducted in-depth research on the formation mechanism of the application of thermal spraying technology on the copper spiral female parts of the rock drill product. The copper spiral female in the friction pair of the rock drill after heat treatment and thermal spraying has been tested on site by the customer. With better results, it is hoped that it can be used as a reference for the study of other friction pairs in rock drill products.

The vibration noise analysis and optimization of diamond circular saw blade is presented. The position of hole of the diamond circular saw blade matrix with diameter of 500 mm is established by analyzing the vibration and noise through experiment, and then making matrix topology optimization to the blade by ANSYS. The research content is divided into three parts. The noise analysis of diamond saw blade. Study on vibration characteristics of diamond saw blades. The optimization design of diamond saw blade. The study on the noise and vibration characteristics of diamond circular saw blade provides some reference for the design and technological parameter of blades. The successful application of the topology optimization has certain reference value to production and manufacturing of saw blades.

The lifespan of a road structure can be evaluated only based on a traffic forecast. After a road is open to traffic, degradations are starting to developed, even at light and moderate traffic levels. Thus, at a specific time moment during the structure's lifespan, the residual life expectation of a road can be determined as a function of the degradation state and the forecasted traffic. The degradation state can be evaluated either by using the approximated characteristics of the road construction materials or, based on the real material properties that are experimentally determined on core samples. If the residual life is estimated based on up-to-date traffic forecasts and real road materials properties, the common reinforcement methods used to prologue the lifespan of the structure can be optimized and adapted to the specific conditions of each type of pavement.

The given paper considers the choice of method and technology of liquefied natural gas transportation from an isothermal LNG storage facility via a pipeline to a transport cryogenic tank. Theoretical studies have been performed, including mathematical modeling of thermal and hydro-dynamic processes during the transportation of liquefied natural gas with partial evaporation through a pipeline. A new method for calculating the transportation of liquefied natural gas with partial evaporation through a pipeline using the gravitational method has been proposed in the paper.