Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section最新文献

{"title":"Notes About Crushing Sand from Bituminous Schist","authors":"Dumitru Hanganu","doi":"10.2478/bipca-2021-0009","DOIUrl":"https://doi.org/10.2478/bipca-2021-0009","url":null,"abstract":"Abstract People have used sand and stone for foundations for thousands of years. Significant refinement of the production and use of aggregate occurred during the Roman Empire, which used aggregate to build its vast network of roads and aqueducts. The invention of concrete, which was essential to architecture utilizing arches, created an immediate, permanent demand for construction aggregates. Construction aggregate, or simply “aggregate”, is a broad category of coarse to medium grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt concrete; the aggregate serves as reinforcement to add strength to the overall composite material. Due to the relatively high hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and roadside edge drains. Aggregates are also used as base material under foundations, roads, and railroads. In other words, aggregates are used as a stable foundation or road/rail base with predictable, uniform properties (e.g. to help prevent differential settling under the road or building), or as a low-cost extender that binds with more expensive cement or asphalt to form concrete. Preferred bituminous aggregate sizes for road construction are given in EN 13043 as d/D (where the range shows the smallest and largest square mesh grating that the particles can pass). The same classification sizing is used for larger armour stone sizes in EN 13383, EN 12620 for concrete aggregate, EN 13242 for base layers of road construction and EN 13450 for railway ballast. Aggregates themselves can be recycled as aggregates. Unlike deposits of sand and gravel or stone suitable for crushing into aggregate, which can be anywhere and may require overburden removal and/or blasting, “deposits” of recyclable aggregate tend to be concentrated near urban areas, and production from them cannot be raised or lowered to meet demand for aggregates. Supply of recycled aggregate depends on physical decay of structures and their demolition. The recycling plant can be fixed or mobile; the smaller capacity mobile plant works best for asphalt-aggregate recycling. The material being recycled is usually highly variable in quality and properties.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122743500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Level of Concrete Hardening by the Maturity Method","authors":"Pamfil Alexandra","doi":"10.2478/bipca-2021-0005","DOIUrl":"https://doi.org/10.2478/bipca-2021-0005","url":null,"abstract":"Abstract Curing levels under standardized temperature and humidity conditions of concrete (but also for medium temperature conditions in the range of +5 o C → +35 o C, maximum +40 o C, depending on the type of cement used in the preparation of concrete, in order not to record final resistance losses) can be plotted graphically with a single chart for all concrete grades prepared with the same type of cement at different ages. Each concrete hardening diagram corresponds to a degree of maturation, defined as the area between the average temperature plot of the concrete and the -10 ° C order, over time, so that only resistance based on the temperature measurement during the curing can be evaluated (or the level of hardening) of the concrete necessary for the technological process - decofing, precompression force transfer, acceptance of freezing of the concrete without adverse effects, precast concrete transport etc., but also the necessary times for starting a technological process.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132940051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review on the Energy Performance and Efficiency of Radiant Floor Heating Systems with Integrated Phase Change Materials","authors":"Marius Brănoaea, A. Burlacu","doi":"10.2478/bipca-2021-0007","DOIUrl":"https://doi.org/10.2478/bipca-2021-0007","url":null,"abstract":"Abstract In the modern society the concept of energy efficiency of buildings has become a subject of great interest, due to the negative impact of buildings upon the environment, society and economy. One of the methods of overcoming this is to provide a better efficiency of the energy storage because it is the key to resolve the difference between supply and demand. In comparison to electro-chemical batteries which provide limited energy storage at a high financially cost, thus in this regard, thermal energy storage technologies with high energy density have increased market potential. PCMs present objective advantages in comparison to classic construction materials due to their characteristics of being able to store and release higher quantities of thermal energy during the phase change process. A PCM radiant floor heating system can provide a reduction of the energy consumption for heating by up to 43%, trough the higher discharge time of the PCM compared to regular heating systems.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134166588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shear Lag and Local Buckling Interaction in Orthotropic Deck of Steel Bridges","authors":"C. Moga, Crina Feneşan, M. Suciu","doi":"10.2478/bipca-2021-0006","DOIUrl":"https://doi.org/10.2478/bipca-2021-0006","url":null,"abstract":"Abstract The term of shear lag is related to the discrepancies between the approximate theory of the bending of beams and their real behaviour, and 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. The effects of the shear lag, plate buckling and interaction of both effects should be taken into account at the ultimate, serviceability or fatigue limit states in the design of structures with wide flanges. In EN 1993-1-5, the concept of taking shear lag into account is based on the effectives 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. Some aspects concerning the shear lag phenomenon and a design example of effectives width calculation and the shear lag effects for a steel pedestrian bridge deck are presented in this paper.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128012720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Notes About Bf Sludge as a Potential Use as Filler in Asphalt Mixture Composition","authors":"D. Nanea","doi":"10.2478/bipca-2021-0010","DOIUrl":"https://doi.org/10.2478/bipca-2021-0010","url":null,"abstract":"Abstract The purpose of the research carried out is to develop a new perspective on a material resulting from steelworks. Currently, the blast furnace sludge from Galati is used as granular material in road construction generally at foundation layer. The bf sludge has the chemical and mechanical potential to be used as filler in bituminous mixture, as a result of its particular composition which does not interact with bitumen, and it has the ability to be crushed in particle fractions. The main constituents of the bf sludge are different oxides, as calcium, aluminium, iron, magnesium, manganese oxides, sulphide. The raw material is homogenous, with no impurities and it is not toxic for the environment. The characteristics of the filler sample was analysed, and its results is compared with standard specifications. The bf sludge was ground into very fine granules, under 2 mm, and then tested in laboratory in standard conditions.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133800582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress-Strain Relation Laws for Concrete and Steel Reinforcement Used in Non-Linear Static Analytical Studies of the Moment Resisting Reinforced Concrete (RC) Frame Models","authors":"I. Sococol, P. Mihai, I. Toma, Ioana Olteanudonţov, V. Venghiac","doi":"10.2478/bipca-2021-0002","DOIUrl":"https://doi.org/10.2478/bipca-2021-0002","url":null,"abstract":"Abstract Following the previous analytical studies performed with ATENA software for a series of RC moment resisting frame models, it were used in the pre-processing stage the stress-strain relation laws for concrete and steel reinforcement. These mathematical and graphical relations represent a necessity in the current conditions of numerical analysis and imply a correct knowledge of the deformation mode of the „reinforced concrete” which is a composite material. Thus, it is desired through this research paper the theoretical exposition of: equivalent uniaxial law for concrete, biaxial compressive failure and tensile failure consideration laws for concrete, bilinear with hardening law for steel reinforcement, cycling steel reinforcement model and steel reinforcement bond model. Finally, it will be possible to validate the correctness of the analytical RC frame systems through the experimental results of the optimal RC frame model after seismic platform testing.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132030416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of Limestone Blocks in Constructions in the Republic of Moldova","authors":"Albu Doina-Cezara","doi":"10.2478/bipca-2021-0004","DOIUrl":"https://doi.org/10.2478/bipca-2021-0004","url":null,"abstract":"Abstract One of the most important problems in modern society is the problem of using natural, ecological, harmless products for humans. In construction, this problem is solved by selecting, combining and using natural, traditional materials for some geographical areas. The most widespread in the world, starting from antiquity, is limestone. The limestone block, the so-called „cotileț”, is a construction material that has been used in masonry for over 60 years on the territory of the Republic of Moldova. In this research is considered dynamic extraction of limestone blocks, are analysed existing excavations and its location, the limestone reserves in Moldova. The technical characteristics of the „cotileț” are studied, such as dimensions, density, water absorption level, softening coefficient and earthquake resistance. At the same time, the existing buildings on the territory of the Republic of Moldova were examined and the characteristics of those built of limestone blocks were highlighted.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121501168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Geodetic Infrastructure of Ungheni District of the Republic of Moldova","authors":"V. Chiriac, Dumitru Nuca","doi":"10.2478/bipca-2021-0001","DOIUrl":"https://doi.org/10.2478/bipca-2021-0001","url":null,"abstract":"Abstract Starting from 1999 a new geodetic reference system MOLDREF99 based on the ITRF97 and ETRS89 was established in Republic of Moldova. The realization of MOLDREF99 is the national GNSS Network with density about 1 point per 15 sq. km. However, this density is insufficient for large spectrum of applications (landslide and floods monitoring, environmental research, geohazard prediction, etc.). In 2011 national positioning service MOLDPOS was put on function with 10 permanent GNSS stations to provide real time positioning services. In order to improve the accuracy of digital terrain models along the Prut River the local quasigeoid model is necessary to develop taking in consideration GNSS/Levelling differences and gravity data. This article is focused on improvement of geodetic infrastructure of the Ungheni district in order to ensure precise and homogenous geodetic data interpretation along the Prut River for flood risk assessment and development of flood risk management plans.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128581370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Importance of Entrepreneurial Management in the Civil Construction Branch","authors":"R. Rusu, Andrei Bejuşcă, I. Șerbănoiu","doi":"10.2478/bipca-2021-0008","DOIUrl":"https://doi.org/10.2478/bipca-2021-0008","url":null,"abstract":"Abstract Entrepreneurship can be defined as a complex process through which a series of resources are mobilized in order to exploit and capitalize on business opportunities and ideas, constituting one of the most important factors that bring a big contribution to the economic growth. The whole mechanism is set in motion by an entrepreneur, represented by individuals or groups, who by assuming in the decision making, innovation and creativity, aim to obtain the maximum profit with a minimum financial effort. The profile of the ideal entrepreneur, either an individual or an organization, is shaped by a series of qualities, including the ability to assume and lead, the capacity for intense effort over long periods, the speed of reactions and the speed of decisions, the efficient organization of work. The efficiency of the entrepreneur’s decisions and activity can be improved by applying an entrepreneurial management system, in order to identify and capitalize the business opportunities.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133890510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Response of Three-Lobed Shape","authors":"M. Irimia","doi":"10.2478/bipca-2021-0003","DOIUrl":"https://doi.org/10.2478/bipca-2021-0003","url":null,"abstract":"Abstract The paper deals with the three-lobed churches, the most representative creations of the ecclesiastic and monumental architecture preserved in the Carpathian-Danubian-Pontic area. Beginning with the fourteenth century, in Moldavia and Wallachia, the old wooden churches, often threatened by the fire, were replaced with stone or brick masonry ones. Unfortunately, strong and enduring earthquakes occur in this area. The stone and brick masonry, with clay or lime mortars, used for three-lobed churches, including their foundations and steeples, were often severely damaged by earthquakes. According to a legend, in the case of the Church of Arges Monastery, usually the damages occurred during the nights. To save the church, by the virtue of an old myth, the Manole Master has immolated his wife into one of the pronaos walls. By that occasion, the whole pronaos was enlarged and the church was no longer damaged. The later research has shown that by reshaping the pronaos, the relative positions of the weight center and the stiffness center have been reversed. Since then, that beautiful church, during its long service of 503 years, was never damaged again by earthquakes. The same happy fate has been experienced by the subsequent three-lobed churches which adopted the same enlarged pronaos.","PeriodicalId":132116,"journal":{"name":"Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section","volume":"227 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125636128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}