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Building integrated photovoltaics (BIPVs) are modern photovoltaic (PV) modules which are integrated into the building’s envelope. Usually, these devices replace the conventional roofing system, but they may be also integrated into the facade. The modules integration has a significant advantage in limiting the overall cost of the construction. Furthermore, building integrated photovoltaics, in comparison to non-integrated ones, don’t require stand-alone systems or allocation of land. This paper presents the state-of-the-art review regarding the existing BIPVs technologies. Also, in the second part of the paper, future research directions are discussed.

This paper deals with multi-story buildings erected mostly in interwar period in seismic areas and designed for gravitational actions only. The typical structural system is reinforced concrete frames and masonry infills. A usual multi-story interwar structure was chosen in order to evaluate its seismic resilience. There were made in situ measurements for its dynamic characteristics. The numerical model was calibrated according to in situ measurements. There were proposed two methods of increasing the seismic resilience. First method consists in improving the resilience by reshaping without reinforcing. The second method is additional to the first. It consists in reinforcing infilled frames in order to take over seismic loads.

Quality is a requirement of the 21st century, ranging from education to construction. Hence, this paper aims to treat in a theoretical but especially in an applied manner the set of concepts which lead to the achievement of quality in construction.

The paper presents aspects related to the verification of the general stability of the bridge superstructures on circular arches with rigid vertical hangers, bridges of open-type or free-standing, without upper bracing.

The paper presents the comparative analyses in terms of dynamic behavior of two scenarios of an RC frame structural system for a duplex house situated in Neamt, Romania a seismic zone with PGA 0.25g. The study shows the structural behavior in terms of vibration modes, horizontal displacements and efforts. The conclusions offer the best argument to chose the preferred structural system by owner.

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.

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.

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.

In this paper are presented different approaches of microbiological type, on the concrete matrix, that has the ability to self-healing the micro-cracks in their early phase. Although the prevention of cracks in the concrete structure is not possible, there are many types of techniques that will lead to self-sealing. Thereby we can say the cracks represent the biggest enemy of the elements in the constructions, and if they are not observed and treated in the early phase, they can create real dangers, both for the constructions and for the people. The micro-cracks appeared in the concrete matrix are determined by a number of internal and / or external factors. The determination of the cause of the appearance of the micro-cracks is done by visual inspections and by direct measurements, using special equipment. The identification of the various biological compounds and their use in autonomous processes can represent a sustainable but also efficient alternative on the costs of concrete production. From the researchers’ reports, the application of chemicals and polymers represents a source of risks for human health, plus the fact that these methods are viable in the short term.

The paper presents the main mathematical relationships for the evaluation of the compressive strength of Portland cement concretes made over time by researchers of worldwide recognized scientific value. The authors use in their relations the influence factors on the value of the compressive strength and the conditions that the components of the concrete must meet. Each mathematical relation was verified by the authors through complex laboratory research and by imposing restrictive conditions for achieving the mechanical performance and durability of the studied concrete. It presents the advantages, disadvantages and scope of use of relations, as well as the possibilities for their application for the present. The relationship established by Feret in 1892 (also reformulated by him in 1896) is a qualitative relationship, which takes into account the absolute volumes occupied by cement, water, occluded air and the quality of the cement; the relationship established by Bolomey in 1935 and completed by the Russian scholar Skramtaev is a quantitative relation, which takes into account the dosages of cement, water and the quality of cement and aggregates. Feret’s relationship, updated in 1999 by François de Larrard, as well as Bolomey’s relationship, updated in 1979 by Dreux-Gorisse, proved their validity and usefulness in evaluating the mechanical performance of Portland cement concrete.

Concrete is one of the most used construction materials but there is also the need to continuously improve it. The high consumption of natural resources and energy when manufacturing cement demand a “greener” approach. One possibility is to partially replace the cement with other admixtures, transforming the material into a more ecological version. In the present paper is also continued the experimental analysis of the possibility to embed various textile structures with a modified mineral matrix.

Concrete is a building material with a continuous demand in the construction industry due to the convenient price-performance ratio. On the other hand, concrete is not an environmentally friendly material. Thus, in order to obtain a sustainable material, wood waste can be recycled and used as light aggregates in the manufacture of precast ecological building blocks. Block walls must satisfy not only structural criteria but also functional requirements. In addition, thermal contribution is important in reducing energy consumption over the life of the building. The presence of moisture on the exterior walls due to the appearance of condensation will decrease the thermal performance of building materials. This paper analyses the occurring of condensation risk and its location in the outer wall made of wood-concrete blocks by the Glaser method, for different situations of arrangement and composition of the layers.

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.

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.