rss_2.0Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section FeedSciendo RSS Feed for Bulletin of the Polytechnic Institute of Iași. Construction. Architecture Section of the Polytechnic Institute of Iași. Construction. Architecture Section Feed Comfort Analysis in Rooms Using Low Temperature Convective and Radiant Heating Terminals<abstract> <title style='display:none'>Abstract</title> <p>The concept of energy is closely related to the building sector and the systems used for heating, implicitly energy saving which is a current problem of both old and new buildings. In this paper a series of numerical simulations were made in Autodesk CFD Simulation in order to study the influence of terminal heating systems over the thermal comfort in rooms. Three case solutions were analysed, as follows: heating a room using a steel radiator, heating a room using an aluminium radiator and heating a room using underfloor heating. The values resulted through numerical simulations for the average room temperature were compared with the values for ideal heating. It was observed that underfloor heating is the most efficient source of heating among those analysed. Compared to heating using radiators, the temperatures along the length and height of the room using underfloor heating are constant and close to the ideal heating. The human body feels the most comfortable due to the uniform distribution of temperature from ground level, on height.</p> </abstract>ARTICLEtrue Rehabilitation of External Walls – Case Study<abstract> <title style='display:none'>Abstract</title> <p>Both at national and international level, the present-day trends relate to the development of high-performance enclosing and insulation systems that make use of modern thermo-energetic rehabilitation methods.</p> <p>Thermal rehabilitation works for the envelope of a building or for the building elements forming the envelope concern the diminishing of the heat losses by increasing the thermal resistances of the enclosing elements and limiting air infiltrations through glazed elements and joints.</p> <p>In most Western European countries, national programmes aiming at the thermal protection of the buildings have been developed. The projects ran in gradual stages, starting after the energy crisis in 1973 and 1979, the outcome being a reduction of the energy consumption.</p> <p>According to the Energy Performance of Buildings Directive issued by the European Commission, at present, buildings are responsible for approximately 40% of EU energy consumption and 36% of the energy-related greenhouse gas emissions (<ext-link ext-link-type="uri" xmlns:xlink="" xlink:href=""></ext-link>).</p> <p>In the paper, a case study is presented, analysed from the point of view of energy efficiency through a new software for computing developed by the author called REBUILD, which leads to the choice of appropriate solutions for the thermal rehabilitation of an element of the building envelope. The recommended solution after the study is intended to bring the structure back to its optimal energy performance and to abide by the current regulations.</p> </abstract>ARTICLEtrue Regarding Concrete Mixes Suitable for 3D Printing<abstract> <title style='display:none'>Abstract</title> <p>3D printed concrete is a relatively new technology that has been gaining popularity in the construction industry in recent years. It involves the use of a 3D printer to deposit layers of concrete in a pre-determined pattern, gradually building up a three-dimensional structure. This process offers several benefits over traditional concrete construction methods, such as the ability to create complex geometries and reduce material waste. One of the main advantages of 3D printed concrete is its ability to produce highly customized and unique designs that would be difficult or impossible to achieve using traditional construction techniques. Additionally, the precision of the 3D printing process allows for greater control over the properties of the concrete, such as its strength and porosity, which can be tailored to suit the specific requirements of the project. Another benefit of 3D printed concrete is its potential for sustainability. By minimizing material waste and using eco-friendly materials, this technology has the potential to reduce the environmental impact of construction.</p> </abstract>ARTICLEtrue Matériaux Innovants Vers Une Nouvelle Ère De Conception Architecturale Innovative Materials for a New Era of Architectural Design<abstract> <title style='display:none'>Abstract</title> <p>With the global energy crisis and the emergence of sustainable development issues, architectural design must be mastered, not only to ensure a comfortable indoor environment, but also to control energy consumption and its impact on the environment. Comfortable buildings, energy efficiency, and positive energy buildings are all current issues that require knowledge of the basic principles of sustainable development in buildings. Moreover, understanding the values that characterize materials is essential today to choose products wisely from a technical and economic point of view. This work proposes to articulate them by focusing on Functionally graded material (FGM) as a design tool. Thus, it seeks to contribute to convert the concept of gradient into reality with accuracy and precision thanks to the manufacturing processes based on the new technology.</p> </abstract>ARTICLEtrue Influence of Dispersing Agents on Soil Particle Size Analysis<abstract> <title style='display:none'>Abstract</title> <p>This article explores soil classification methods and the influence of using dispersing agents in various amounts for the soil particle size analysis. Laboratory testing with different dispersing agents was conducted to analyze the effects of sodium hexametaphosphate and lithium carbonate for two different soils with plasticity indices indicating one to be with low plasticity (PI = 8.23 %) and the other one with high plasticity (PI = 39 %). The article highlights differences in the granulometric fractions reported for each soil and usage of the same dispersing agent but in various amount. Thus, the classification of soils is influenced by the amount of the used dispersing agents, recommendations of standards being different in time and countries. These findings contribute to a better understanding of the anticipated behavior of fine soils and provide useful insights for various geotechnical applications.</p> </abstract>ARTICLEtrue of Adjustments the Cost in Constructions<abstract> <title style='display:none'>Abstract</title> <p>The aim of this article is to show the impact of adjustments in construction projects. The methodology and impact of costs in construction are analyzed by applying the formula for calculating the cost of price adjustments based on inflation. The cost of a project is defined by its direct and indirect costs, but in projects carried out by the state, there are adjustments to the cost. The adjustment cost is intended to take over a price increase due to changes that are not related to the project and are related to the market economy of the construction industry.</p> </abstract>ARTICLEtrue Methods of Photovoltaic/Thermal Panels. State-of-the-Art Review<abstract> <title style='display:none'>Abstract</title> <p>The concept of green energy and sustainability is no longer just an abstract idea intended exclusively for theoretical, numerical and experimental studies, but a “must” of our days. It is a reality that needs to be applied now, not later. Photovoltaic panels are an essential tool in implementing the idea of sustainability, green energy and NZEB (Net Zero Energy Building). Moreover, photovoltaic thermal panels represent the next step, being the main actor in increasing the efficiency of photovoltaic systems. The main challenge is the amount of electrical energy and thermal energy produced by these systems, which leads us to the need to determine the optimal method of cooling the PV. The current working document is intended to be a review of PV cooling methods, how their efficiency is influenced and a preamble for further research on how to optimize photovoltaic / thermal panels integrated in buildings.</p> </abstract>ARTICLEtrue of Microconcrete Produced with Fly Ash and Ultrafine Silica<abstract> <title style='display:none'>Abstract</title> <p>Microconcrete is an important subclass of regular concrete that lacks the coarse aggregate commonly found in standard concrete. This makes it a good candidate for certain casting operations, such as densely reinforced elements. Microconcrete also tends to have better workability and smoother flow in formwork elements than regular concrete. However, one of humanity’s current problems is air pollution caused by chemical, physical, or biological agents with harmful effects on the environment. Carbon dioxide (CO2) resulting from cement production is a major atmospheric pollutant. To align with sustainable development standards, the construction industry must seek alternative materials that are more environmentally friendly. This article presents a comparison of the properties of regular microconcrete and microconcrete with additives such as fly ash and ultrafine silica. This topic is important because environmental issues are becoming more pressing. The results show that using waste products as additives in microconcrete can provide a sustainable solution for reducing carbon dioxide emissions and environmental impact. Although lower strengths were obtained compared to traditional concrete, microconcrete with waste products can be used in various applications, such as the production of prefabricated construction elements or the rehabilitation of existing structures. Additionally, it can be used in the construction of paving stones, sidewalks, or industrial floors, contributing to reducing pollution and environmental impact.</p> </abstract>ARTICLEtrue of Safety of Road Infrastructure and Transport Networks<abstract> <title style='display:none'>Abstract</title> <p>The aim of the work: consists of significantly reducing the number of road disasters. The objectives of the investigation: to outline the causes that generate serious traffic accidents on Stefan cel Mare Boulevard, to make rational analysis and planning of measures to improve the situation, to unveil the existing problems on local level, the composition of traffic flows, as well as skills of specialists in the realm, to develop a strategy on road accidents resulting in casualties aiming to reduce the number of traffic accidents with injuries, to promote measures aiming to protect participants in traffic, to developing a set of procedures and functions which would provide, in a network of certain streets, the size and structure of traffic flows, areas (major and minor intersections, streets) where there is an increased risk of accidents; to identify possible solutions aiming to increase road safety, specific peculiarities of Chisinau city.</p> </abstract>ARTICLEtrue Testing of Beam to Column Dowel Connection<abstract> <title style='display:none'>Abstract</title> <p>This study investigates the behaviour and failure mechanisms of beam-to-column dowel connections in precast industrial halls under lateral loads. Two large-scale cyclic tests were performed to evaluate the assembly failure and its relationship with the dowel connection. The results demonstrated that the assembly failure coincided with the dowel connection failure, governed by dowel yielding and concrete spalling of the column fork. No significant damage was observed in the concrete elements outside the connection area. The dissipative failure mechanism of the column was not achieved, indicating that this dowel connection is not capable to transmit sufficient lateral load. The maximum capacity of the dowel connection was influenced by the concrete coverage of the dowel in relation to the side of the column fork. This research serves as a basis for further investigation and potential improvements in the design and performance of connections in precast concrete structures.</p> </abstract>ARTICLEtrue Design - General Principles and Implementation Strategies in Building Design<abstract> <title style='display:none'>Abstract</title> <p>The built environment, through the consumption of energy from non-renewable sources and the associated CO<sub>2</sub> emissions, as well as through the production of waste throughout its life cycle and the effects of soil and water degradation, contributes significantly not only to the phenomenon of climate change, but also to the irreversible degradation of the natural environment. The concept of regenerative design provides a framework for a holistic approach to these issues in order to identify the most effective remedies, proposing the restoration and regeneration of the global socio-ecological environment through a system of engineering practices suitable to the specific context. The defining aspects of the regeneration applied in the buildings sector refer to the architecture and inserting in the natural environment ensuring a healthy and well-being indoor environment, reducing to zero the consumption of energy from non-renewable sources and promoting renewable energy sources, minimizing carbon footprint by rational use of materials and waste management throughout the life cycle.</p> </abstract>ARTICLEtrue Aspects Regarding the Ductile Seismic Design Concept of the Pure Moment Resisting (MR) Reinforced Concrete (RC) Frame Systems (A Theoretical Study)<abstract> <title style='display:none'>Abstract</title> <p>Seismic activity in the last two decades validate the urgent improvement requirement of the ductile seismic design concept for the MR RC frame structures. This necesity of improvement comes from the unfavorable recorded seismic response of the MR RC frame structures required to on-site seismic actions. The same observations and conclusions (regarding the soft storey (<bold>G</bold>round <bold>F</bold>loor (GF) or <bold>C</bold>urrent <bold>F</bold>loor (CF)) mechanism development and the seismic energy dissipation process in the RC columns marginal zones) were registered in the analytical research and the experimental studies on seismic platforms. The fragile rupture mechanism of the vertical structural elements produces the segmentation of the superstructure into rigid and fragile segment portions. In these conditions, the fundamental seismic response mechanisms and the seismic design elements of the MR RC frame structures found in current practice and considered in actual seismic design standards are specified through comparative methods. In the final chapter of the current theoretical research study, it were specified the main conclusions and immediate improvement necessity of the ductile seismic design concept for MR RC frame system.</p> </abstract>ARTICLEtrue of the Physical-Mechanical Characteristics of Non-Cohesive Soils Stabilized with Fly Ash (Part II)<abstract> <title style='display:none'>Abstract</title> <p>The unprecedented scale of road network development programs in our country requires the consumption of materials (natural aggregates, binders), often non-renewable and expensive, which are difficult to secure from traditional sources. Alternative solutions for the replacement of natural aggregates, binders, as viable alternatives to classical technologies, the adoption and continuous development of recycling technologies are concerns of researchers, designers and road builders. So, the stabilized mixtures successfully form the sub-grade layers of the rigid road structures or both the sub-grade layers and the base layers of the semi-rigid structures (Zarojanu, 1976).</p> <p>Compared to traditional, untreated, thick foundations, the stabilized foundations, consisting of a series of thinner layers (assizes), with considerably increased rigidity, ensure a more judicious distribution of traffic loads for lower overall thicknesses of the road structure (Boboc, 1995).</p> </abstract>ARTICLEtrue of Design Parameters on General Stability of Tied Arches with an Upper Bracing<abstract> <title style='display:none'>Abstract</title> <p>The paper shows the influence of some design parameters on the general stability of a single-track railway bridge, having the structure made of circular steel arches with rigid vertical hangers.</p> <p>The following structural parameters were considered in this analysis: closed bridge with an upper winding made of horizontal members without links (diagonals) between them; closed bridge, with upper winding made of horizontal elements and ties made in the form of cross diagonals; static scheme of the arch in the transverse direction – hinged, fixed or portal frame. The analysis carried out is based on the normative SR EN 1993-2:2007. Eurocode 3: Design of steel structures. Part 2: Steel Bridges (EC3-2). The results obtained can be useful in the design of the arches structures for the field of bridges or other types of metal structures.</p> </abstract>ARTICLEtrue Short Note on the Degradation and Consolidation of Masonry Structures<abstract> <title style='display:none'>Abstract</title> <p>This paper discusses the factors that can lead to the degradation of masonry structures and provides an overview of the existing techniques for their rehabilitation and consolidation. The degradation of masonry is often related to negative actions of the environment, such as water penetration, freeze-thaw cycles, chemical attacks, and exposure to pollutants. These factors can lead to the appearance of cracks, scaling, erosion, and other types of deterioration of masonry. To preserve masonry structures, frequent monitoring and repairs (locally), preferably immediately after any degradation, are the most important measures. When degradation occurs, prompt action is necessary to prevent further deterioration and to apply appropriate rehabilitation and consolidation methods. Rehabilitating a construction involves replacing or restoring degraded elements to restore functionality to the pre-degradation level and to improve the overall performance of the structure. In contrast, consolidation focuses on strengthening an existing structure by adding new structural elements or by applying specific consolidation techniques with the aim of achieving increased structural capacity. These processes are often interconnected and part of a larger process of restoring or maintaining buildings or structures. Regarding traditional solutions for consolidating masonry elements and structures, these consist of repairing or rebuilding affected areas with classic materials, such as simple or reinforced mortars, welded meshes, dowels, steel bars and profiles. Traditional masonry repair works include filling cracks by injection, partial disassembly of walls followed by reconstruction, dismantling of mortar joints followed by deep filling, stitching of cracks with steel dowels, and reinforcing and facing with mesh or mortar. These techniques are applied according to the degree and type of degradation of the existing structure, as well as local and environmental conditions, with the aim of ensuring efficient and durable consolidation of the structure. The informed decision on the rehabilitation or consolidation solution used and how it is to be applied is usually made after extensive studies and consultations to achieve the best possible result. Generally, masonry structures are considered very resistant and durable, due to their history of over 6000 years. However, proper care and attention to detail are crucial to prevent degradation and to maintain masonry structures in good condition.</p> </abstract>ARTICLEtrue Solutions Regarding Ductile Seismic Response Development in the Pure Moment Resisting (MR) Reinforced Concrete (RC) Frame System<abstract> <title style='display:none'>Abstract</title> <p><bold>M</bold>oment <bold>R</bold>esisting (MR) <bold>R</bold>einforced <bold>C</bold>oncrete (RC) frame system presented in the current seismic design standards and required to on-site seismic action develops the soft storey mechanisms. In practice, the idealized and theorized ductile seismic response specified in the seismic design standards for this structural system type does not occur. In these conditions, the current research study presents a logical scheme regarding the development method of the MR RC frame system. The main element of the logic scheme is the seismic response of the RC frame systems designed only for gravity loads. In correspondence with the structural deficiency sources, several aspects regarding the seismic design method were established, followed by the improvement of the ductile design concept. Also, a couple of solutions regarding plastic hinges control and plastic hinges concentration in the marginal zones of the RC beams are presented. These solutions are directed to existing MR RC frame structures and new MR RC frame systems designed in accordance with the current seismic standards.</p> </abstract>ARTICLEtrue of the Physical-Mechanical Characteristics of Non-Cohesive Sub-Grade Layers Stabilized with Fly Ash (Part I)<abstract> <title style='display:none'>Abstract</title> <p>In the execution of the foundation layers and the road base it is necessary to reduce the costs of their construction by using local materials (ballast or crushed stone). In some cases, the physical-mechanical characteristics of the local materials do not satisfy the conditions for dimensioning the road structure. Therefore, to improve these characteristics, they are stabilized with hydraulic binders (fly ash or various mixtures based on lime and cement). By using hydraulic binders, the aim is to obtain a speed in execution, to increase the physico-chemical and mechanical characteristics of the local aggregates and implicitly to reduce the overall costs of the work (Zarojanu, 1976).</p> </abstract>ARTICLEtrue and Experimental Aspects Regarding Non-Isothermal and Inhomogenous Air Jets<abstract> <title style='display:none'>Abstract</title> <p>The practical applicability of non-isothermal and inhomogenous air jets determined researchers concerned with their study to analyze from a mathematical and experimental point of view the technical elements related to this phenomena. The identified aspects were likely to generate the circumstances for the practical improvement of the systems that involve the presence of the nonisothermal and inhomogenous air jets, the researches highlighting different methods for determining the relevant technical parameters from this perspective.</p> </abstract>ARTICLEtrue on the Factors Affecting in Situ Measurement of the Thermal Resistance of Building Elements<abstract> <title style='display:none'>Abstract</title> <p>A current global effort is being made in order to find solutions that will limit global warming. The building sector is responsible for the highest share of total energy consumption, which requires the continuous development of strategies to increase buildings energy efficiency. Considering the high share of emissions generated by buildings, improving buildings energy performance can significantly slow down global warming.</p> <p>A key point in developing strategies to reduce energy consumption and making more accurate forecasts of the evolution of global warming is to determine the actual energy consumption generated by the use of buildings, which in some cases may differ from the theoretical one. In order to determine the actual energy consumption, with high accuracy, determinations in situ of the thermal resistance of the building elements that form the envelope, are essential.</p> <p>The article presents the main methods for determining the thermal resistance of building elements in situ, factors influencing the accuracy of the results, and recommendations for the use of methods to reduce the risk of errors.</p> </abstract>ARTICLEtrue Analysis of the Workability of Stockable Asphalt Mixtures<abstract> <title style='display:none'>Abstract</title> <p>The comparative analysis on the workability of storable mixtures is intended, through the mathematical interpretation of the results, to improve the solutions for repairing local degradations by using storable mixtures.</p> <p>The test of workability of the storable mixture at various bedding temperatures, but also during the storage period of the storable mixture came as a need to establish other tests to determine the physical-mechanical characteristics in addition to the attempt to establish the apparent density imposed by NE 025-2003 (NE 025-2003; Bambang, 2005).</p> <p>The laboratory tests aimed to highlight the interaction between the complex mechanical behavior of storable asphalt mixtures and the variability of the factors acting on a road structure, the results being interpreted using the mathematical analysis software "Curve Expert Professional".</p> </abstract>ARTICLEtrue