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Over 300 million tones of industrial wastes are being produced per annum by chemical and agricultural process in India. These materials pose problems of disposal and health hazards. The wastes like phosphogypsum, fluorogypsum and red mud contain obnoxious impurities which adversely affect the strength and other properties of building materials based on them. Out of several wastes being produced at present, the use of phosphogypsum, fluorogypsum, lime sludge, hypo sludge, red mud, and mine tailing is of paramount significance to protect the environment. Paper making generally produces a large amount of solid waste. Paper fibers can be recycled only a limited number of times before they become too short or weak to make high quality paper. It means that the broken, low-quality paper fibers are separated out to become waste sludge. All the inks, dyes, coatings, pigments, staples and ”stickies” (tape, plastic films, etc.) are also washed off the recycled fibers to join the waste solids. The shiny finish on glossy magazine-type paper is produced using a fine kaolin clay coating, which also becomes solid waste during recycling. This paper mill sludge consumes a large percentage of local landfill space for each and every year. Worse yet, some of the wastes are land spread on cropland as a disposal technique, raising concerns about trace contaminants building up in soil or running off into area lakes and streams. Some companies burn their sludge in incinerators, contributing to our serious air pollution problems. To reduce disposal and pollution problems emanating from these industrial wastes, it is most essential to develop profitable building materials from them. Keeping this in view, investigations were undertaken to produce low cast concrete by blending various ratios of cement with hypo sludge. This project is concerned with experimental investigation on strength of concrete and optimum percentage of the partial replacement by replacing cement via 10%, 20%, 30%, 40%, 50%, 60% and 70% of Hypo Sludge.

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 the present paper is analysed concrete behavior from strength structure elements, subjected to combined sulphatic and magnesian aggressive actions. In order to clearly relieve cement influence regarding corrosion behavior and to be as close as possible of concrete structural characteristics, tests are realized on standard mortars, which from compositional point of view are mocro-concretes. These were used different W/C ratios in order to obtain different structural characteristics, knowing that in the first period after casting, when concrete porosity is sensibly higher, corrosion process is more emphatic, with subsequent negative effects. It was taken into account the fact that sulphatic corrosion effect appears after a long duration of aggressive agent action, in the present paper proposing a three year duration for aggressive attack. In the same time it was considered the fact that usual cement for structural elements is composite cement type CEM II/A-S 32,5, studying combined sulphatic and magnesian corrosion evolution on a large type of micro-concrete compositions with different compactness and aggressive agent concentrations.

This paper is about the interpretation of the 1755 Lisbon earthquake as a historic accident. The paper is divided in two main parts: the commemoration of the 250th anniversary of the 1755 Lisbon earthquake in 2005 and the reaction to other times, as today. Especially a comparison is highlighted, the reaction to the 2004 Sumatra earthquake and Indian Ocean tsunami in 2005 and today, as, contrary to what happened immediately after, the 2004 event did not cause a discourse. Also compared to other historical events mentioned, the Lisbon earthquake remains the only historic accident, and one of the birth dates of modernity. Some key aspects are discussed, as the issue of ruins, or of rebuilding, in context of the 18th century and today. Overall, the accent lays on the view from the Humanities, not of earthquake engineering, and reviews such views at the events and publications about the earthquake.

Different strengthening techniques have been developed so far for the reinforced concrete slabs with or without cut-outs. The development of these methods was a necessity due to different causes, such as inadequate maintenance, overloading of the reinforced concrete member, corrosion of the steel reinforcement and other different situations that appeared in time. Each of the techniques that are presented in this paper is better suited for a given situation and come with their advantages and disadvantages. These techniques are considered to be traditional do to their long usage in time and that they involve only traditional construction materials such as concrete and steel. The five techniques from this paper have been and are the most effectively used, in the past and present days, worldwide and a short presentation of the methods and the way they are applied is presented in this paper. The selection of one of these methods is imposed by a sum of technological and economical factors.

The types of slit walls energy dissipators, from monolith or precast reinforced concrete, proposed by researchers and the seismic behaviour of these types of walls are described. The overall ductility of the structure increases, considering the energy dissipation solutions proposed by the researchers of the reinforced concrete walls, resulting a supplementary safety for the structure. The objective of these solutions is to create an ideal structure for tall multi-storey buildings, that behaves as a rigid structure at low seismic action and turns into a flexible one in case of a high intensity earthquake action. The solutions for increasing ductility proposed in this paper are viable and easily to use in constructions practice. For the analysis of slit wall, the researchers used a series of analytical calculation methods, among the most important being the equivalent frame method and the finite element method, both presented s. 3 of the paper. The researchers concluded that by using this calculations methods, the dynamic behaviour of the reinforced concrete slit walls can be simulated very accurate and realistic.

In order to calibrate a friction damper which uses automotive brake pads it is necessary to determine the compression behaviour of the friction material. This paper summarizes the experimental results obtained for a set of automotive brake pads made in Romania. These results are useful in order to determine the slip load level in a seismic energy dissipation mechanism which uses this type of friction pads. The paper presents the experimental set up and the compression behaviour curves obtained for a set of four commercial brake pads. The testing was performed by the author as a part of his research work, using a hydraulic compression press.

The present paper presents a heat-recovery apparatus with heat pipes, originally designed by the authors for the controlled mechanical ventila-tion systems to ensure the comfort in the insulated buildings. The paper highlights a close correlation between the heat pipes heat exchangers and the concepts of thermal comfort, energy economy, environment, etc.

The concept of ductility estimates the capacity of the structural system and its components to deform prior to collapse, without a substantial loss of strength, but with an important energy amount dissipated. Consistent with the „Applied Technology Council” (ATC-34), from 1995, it was agreed that the reduction seismic response factor to decrease the design force. The purpose of this factor is to transpose the nonlinear behaviour of the structure and the energy dissipation capacity in a simplified form that can be used in the design stage. Depending on the particular structural model and the design standard the used values are different. The paper presents the characteristics of the ductility concept for the structural system. Along with this the general way of computing the reserve factor with the necessary explanations for the parameters that determine the behaviour factor are described. The purpose of this paper is to make a comparison between different international norms for the values and the distribution of the behaviour factor. The norms from the following countries are taken into consideration: the United States of America, New Zealand, Japan, Romania and the European general seismic code.

The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

Most basement water problems appear and it is always necessary to prevent and to eliminate them. If these problems occur at a new and very important building, the solutions must appear immediately. The paper describes the research made at the Orthodox Cathedral of Bacau, Romania, from the point of view of the water appeared in the basement and in the Civil Defense Shelter in the early 2007. The research used the results of two geotechnical profiles, which show bedding consisting of a packing layer of 2.00 m thick, a fine sedimentary horizon of 6.00 m thickness and a coarse sedimentary horizon at -8.00 m depth. Groundwater is quartered in the coarse sedimentary horizon, the latter ranging from 10.00 m to 11.00 m below the Natural Ground Elevation. After the presentation of sources from where water could come, the paper presents some water leak mitigation methods to be used at the Orthodox Cathedral of Bacău

The aim of this paper is to analyse the influence of windows in Bucharest climatic zone of the România through the simulation of the energy balance in a dwelling. This simulation may provide a comparing way for the energy saving design in the future buildings and some suggestions for the architects to adopt the optimal type of window according to local conditions. We give an overview of how windows are modeled in the Window6 Simulation Program. In this paper, several kinds of windows are introduced and compared using the Window6 and ISOVER Software. In addition, the potential energetic efficiency of four representative windows in Bucharest city of the România are analysed and compared using the CASAnova Software. Example results of calculation are shown too.

Romanian higher education began a long time ago, having its own national specificity but being also influenced by the education from other developed countries. Between 1813 -- 1840 Gh. Asachi created the School of Terminal Engineering, establi-shing the foundations of the Technical Engineering University. In Moldavia, higher education in engineering, in the field of roads and bridges, coincides with the official opening of the Faculty of Construction of Jassy, in 1941, as part of the Polytechnic Institute, today the „Gheorghe Asachi” Technical University. Over the years, this type of education has evolved and developed, under the influence of schools of engineering such as The School of Bridges and Roads in France. The French School of Bridges and Roads was created by a decree of the king, on the 14th of February 1747. In two and a half centuries, it has trained about 15,000 engineers, who accomplished great works both in their native country and abroad. The reputation of this school is based especially on the discoveries, the accomplishments and the activity of these engineers, who have a great impact on the development of this institution. Most of these engineers did not go down in history (we seldom know the name of the person who built a bridge or a road). We remember some of them by a formula, a machine, a plate on a road, without actually knowing who is the person behind the name. Shaping their portraits, we could bring them back to the memory of the public, emphasizing the common aspects of their professional training at the School of Bridges and Roads. A free professional background, of a high scientific level, comprising a lot of practical issues, based on public transport in the beginning, where reflection and action play an important part. Except a lot of great scientists (among them, a Nobel prize laureate), inventors, entrepreneurs, engineers with prestigious accomplishments, there are also politicians (even a president), writers, a navigator. The selection of these personalities was difficult and can be contested. It was not intented to establish a hierarchy, but only to create a gallery of portraits, the only criterion taken into account being the exclusion of those engineers who are still alive. Unfortunately, there is no woman among these portraits, because their access was only permitted in 1959 for civil engineers and in 1975 for the others. We hope that this anomaly will be redressed in the paper celebrating 300 years of existence of this school. After a quarter of a millennium, in the 21st century, the oldest civil school of engineers in the world, created during the reign of Louis XV, remains what it has always been: a way of modern training in the benefit of the nation and of society, having the ambition to instruct a quality personnel, able to adapt to the problems and needs of its epoch. With a prestigious heritage, the School of Bridges and Roads has evolved and transformed during its 250 years of existence, always remaining proud of its past and at the same time open towards the future. Many authors have already mentioned the history, rich in events, of this institution. We shall try to describe it concisely in the present paper. We shall present some portaits of well-known engineers: great constructors, inventors, scientists, making themselves known in other areas than their initial training, they illustrate a less known aspect of the life of the roads and bridges engineer, a rich, intense, varied life and activity. The objective of this paper is to allow a better understanding of what has been, over the past 250 years, the french School of Roads and Bridges.

The aim of this paper is to propose an original optimization approach using the concept of computational design of experiments and response surface methodology to check the curvature in numerical experiments. Generally, for the study of the strongly nonlinear phenomena, it is recommended to use a second-order model. This paper proposes a new technique to estimate a quadratic effect for a model based on finite element simulations and the Design of Experiments. Therefore, it is very important that the proposed technique (adding center points) controls other properties of the design matrix, especially orthogo¬nality for the response surface methodology and brings more information for the quality of the proposed model. The computational design of experiments is considered an advantage in comparison with design of physical experiments because generally computer solutions cost less than physical testing. The bending process optimization is used to improve the performances of this approach.

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.

The actual trend of performance based modelling of the seismic action is to adopt probabilistic models of the seismic hazard. In the first part of the paper are presented theoretical aspects of the seismic hazard definition from the probabilistic point of view as „a function P(Y > y) that describes the probability that in a given region (M) and for a time interval (T), the value of a parameter, Y (for example: macroseismic intensity, acceleration, velocity and displacement of the soil) to overpass the given value (y) as an effect of a seismic event” [4]. The probabilistic study of the seismic hazard gives the possibility to implement new parameters, such as: the likeliness and the occurrence frequency of the seismic events. Nowadays most of the international standards adopted the probabilistic analysis of the seismic hazard as a complementarity of the deterministic analysis. In the second part of the paper are presented the results of the probabilistic analysis for Vrancea region using the Gumbel 1 probabilitic model that has the parameters determined throughout the extreme values statistical method.

Retaining walls are large category of engineering structures of multiple uses, having an essential safety ensuring role. The structural systems are varied because the situations and requirements derived from both site conditions and other criteria are varied. The paper enlarges upon retaining walls systems that use an outstanding amount of precast units and multiple cylindrical vault type structural systems supported by abutments [1], [2]. The paper proposes extending the structural system to retaining walls and develops certain specific issues. Some considerations regarding structural design are made.

Integral bridges, or integral abutment and jointless bridges, as they are more commonly known in the USA, are constructed without any movement joints between spans or between spans and abutments. Typically these bridges have stub-type abutments supported on piles and continuous bridge deck from one embankment to the other. Foundations are usually designed to be small and flexible to facilitate horizontal movement or rocking of the support. Integrally bridges are simple or multiple span ones that have their superstructure cast integrally with their substructure. The jointless bridges cost less to construct and require less maintenance then equivalent bridges with expansion joints. Integral bridges present a challenge for load distribution calculations because the bridge deck, piers, abutments, embankments and soil must all be considered as single compliant system. This paper presents some of the important features of integral abutment and jointless bridge design and some guidelines to achieve improved design. The goal of this paper is to enhance the awareness among the engineering community to use integral abutment and jointless bridges in Romania.

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.

Structures rarely achieve structural symmetry. Even in symmetric structures, the asymmetric position of the structural components tends to produce an effective asymmetric structure. Such an asymmetry even if is small, can produce a torsional response coupled with translational response. In the torsional analysis, the provisions of the seismic norms are based on determining the static eccentricity. In this paper is presented a general way of computing the eccentricity in torsional design. The purpose of this article is to make a comparison of the general rules used to determine the eccentricity and their values. Are taken into account the norms from: Romania, Europe, Japan, Germany and the United States of America.

In achievement of slope load sustainability using mixed soil technique, is considered acceptable the method for slope construction technology. This paper deals with evaluation of mixed soil technique for construction of stable slope and proves the soil capability by analysis of computerized modeling, the revealed result of investigation, the possibility of using nearest local material, reducing project cost, solving the construction geotechnical problem and accurate understanding of soil property when it is developed under different types of geometry.

The main idea of this paper is to analyse the means for the rehabilitation of our cultural heritage timber structures. Several methods together with their application techniques are described, and also, the reasons for what these strengthening operations become imminent at a point. First of all, the necessity of the timber structural elements strengthening is explained through a short presentation of the factors which are degrading the material. Then, certain precautions and strengthening procedures are presented, all involving the usage of traditional materials like wood, metal, or concrete, and of modern materials like fiber reinforced polymeric composite.

The reduction of buildings heat losses and pollutants emissions is a worldwide priority. It’s intending to reduce the specific final energy consumption under limit of 120...150 kWh/m2.yr and even under 15...45 kWh/m2.yr, foreseen in 2020 for the passive houses, which is necessary for a sustainable development and for allowing to became profitable the use of unconventional energies [1]. These values can be achieved through the use of thermal insulations, for protecting the constructions fund and through making envelope elements, as much as possible, from materials with a high thermal resistance, for new buildings. With intention to substitute the conventional thermal insulations: mineral wool, expanded polystyrene, which are both great energy consumers, it’s proposed, among others unconventional technologies and materials, the use of vegetable wastes both as a thermal insulation material and as a material used for building load-bearing and in-fill straw-bale construction. In speciality literature there are presented experimental determinations of this material’s thermal conductivity. The paper proposes a simple method, adequate for the measurement of thermal conductivity for bulk’s materials as straw bales.

This paper provides initially an overview of some general issues associated with the robustness of structures. Firstly, a brief discussion related to the progressive collapse, from its basic definition, to the inherent difficulties of understanding, analysing and mitigating this phenomenon is presented. Attention is also drawn to the potential sources of abnormal loads that should be examined when designing for progressive collapse performance. In addition, some of the design standards that have been developed, and methods for designing to progressive collapse hazards, are discussed. Finally, a numerical analysis of a four storey reinforced concrete frame structure has been carried out and the results concerning the assessment of a progressively damaged structure are presented.

Providing safety of structures is one of the main aims of design. In traditional design it is achieved by designing structural components against specified limit states. However, as showed the Ronan Point collapse in UK in 1968, when a gas explosion in one of flats on the 18-th floor of the residential building caused the failure of an entire section of the building, this approach is not sufficient. The approach does not exclude the risk of local damage to a structure due to accidental events that can occur during service life of the structure. While probability of occurrence of such events for ordinary structures is low, and, therefore, they are not considered explicitly in design, their effect on structural safety becomes significant if the structure is not robust, that is when some local damage can trigger a chain reaction of failures causing collapse of the whole structure or of a major part of it, the so called progressive collapse. The purpose of this paper is to outline the basic premises for the utilization of risk assessment in evaluating the robustness of structures. In the following the robustness assessment is understood as a process of decision making based on risks.

The paper presents the results of a study concerning the efficiency of a heating installation with a condensing boiler using liquid fuel, equipped with an accumulator and burnt gases separator. The given up heat in the gas separator is taken over and accumulated through a heat pump. The energetic efficiency of the primary heating functioning regime was established at 94% after the measurements and at 95.8% through calculus.

This paper approaches the problem of diagnosing the degradation and the safety estate in exploatation of the cylindrical tanks made out of pre-prestressed concrete, affected by execution errors, especially generated by the design non-observance stipulations, being suggested by a situation which hasn’t been signalized into the specialty literature from our country. The effectuated study aimed to evaluate the functional capacity of cylindrical tanks, being proposed an original way (methodology) of identifying the real loading level of the horizontal sections from the walls of the pre-prestressed cylindrical tanks with cables and which relies on an original grapho-analytical procedure. This way there were realized etalon-graphics for different types of tanks and their geometrical and technical characteristics which allow a soft evaluation of the nominal functioning capacity of the analysed objectives, by comparing the quantity of existing reinforcement with the need quantity.

The paper presents the characteristics of the self-compacting concretes, their advantages and disadvantages when they are used in buildings. Due to its properties and composition, the self-compacting concrete is described here as being one of the future friendly enviromental material for buildings. Tests concerning to obtaining a self-compacting concrete, together with the specific fresh concrete properties tests, are described.

After realizing numerous constructions in the world, which use Bubble Deck concrete slabs with spherical gaps, valuable information were gathered, allowing a rigorous processing and systematization, with the purpose of realizing an experimental and documentary study. The paper presents some experimental programs which refer to concrete slabs with spherical gaps, existing in similar execution and loading conditions as those from a real construction; this implies the realization of a monolithic slab element at a scale of 1:1, which will be subjected to static gravitational loadings in order to determine the deformation (deflection), cracking and failing characteristics. The resultant conclusions will be used in defining the failing mechanisms, very useful in the formulation of an adequate mathematical model. The research proposed in the project offers an answer to the major objectives of the development of calculus methods and existent prescriptions of the concrete slabs with spherical gaps. The realization of the proposed objectives involves documentation activities, theoretical study, collaboration with different other partners, gathering and processing of the results obtained in laboratory and even in situ.

The interest in the non-conventional energy resources, a consequence of the severe restrictions imposed towards pollution of any kind, arises again the interest in using solar collectors. Implanting them on the terraces of new or existent home residencies, or any kind of other buildings, means to solve a sum of engineering problems, among them being also the stages of safely designing the plane panels for collectors and the sustaining skeleton, made in steel as well as the fixing systems adopted for the interface with the building itself. The necessity of considering the maximum wind speeds actions along other dynamic effects of its turbulence is the result of a many years experience, specially if one must also think in terms of efficiency and costs both for construction and exploitation. The pattern of the wind flow field suffers intricate alterations in the proximity of these collectors placed in the vicinity of the building surface and, in these situations, it is common to test the models at a reduced scale in wind tunnels with atmospheric boundary layers. The experimental study presented in this paper was undertaken in the Laboratory of Aerodynamics of the Faculty of Construction and Building Services in Iaşi and it reveals the results and the conclusions drawn from the analysis of the wind flow over a row of collectors differently arranged in order to evaluate the wind pressure coefficients used in design.

The large variety of modern composite materials and products existing nowadays in the construction market provides multiple and convenient possibilities to use them in both structural and nonstructural industrial construction elements. The main advantages of modern composite materials such as: corrosion resistance, high strength and modulus values compared to their density, acceptable deformability, tailored design and excellent formability enable the fabrication of new elements and the structural rehabilitation of the existing parts made of traditional materials. The high potential of the applicability of polymeric composites in new industrial construction correlated with fabrication procedures as well as the use of composites in modern strengthening solutions are presented in the paper.

The specialized literature concerning the Geotechnical Engineering Field indicates the problems due to soil liquefaction and the aggravating consequences that liquefaction phenomenon may cause to buildings. Some procedures of foundation soil improvement for both existing and future foundations are presented. The paper also presents three soil remediation methods involving a low level of vibration generated in the process of foundation soil improvement and two case studies representing the usual method in Romania.

The seismic protection is, without any doubt, a worldwide priority, and that is why one of the main preoccupations of the researchers in the field is finding some innovative concepts concerning the seismic protection of the structures. The aim of the paper consists in the analytical and numerical study of the variable orifice damper implemented in a single degree of freedom (SDOF) structure in order to increase people’s safety and reduce the seismic risk. The variable orifice damper is the common semi-active hydraulic device which may be utilized as part of seismic isolation system or within the lateral bracing of a structure. The semi-active control strategy is realized using on-off clipping control algorithm. It is concluded that the variable orifice damper afforded a substantial reduction of the displacement response of a SDOF system in comparison to the response with passive control fluid device.

Mechanical joining techniques are used in construction industry all over the world on a daily basis. A further method of joining has proven to be highly successful – adhesive bonding. Known for thousands of years, adhesive bonding has become as important as other joining techniques as a result of the pace of developments in recent years. In many areas, this bonding technology has become a key technology. Virtually, all solid materials can be connected with one another using adhesives. Although bonding fibre reinforced polymeric composites to the concrete substrate is a relatively simple technique, the proper installation of the fibre reinforced polymeric composites is essential to ensure the adequate performance of the hybrid system. Since the installation procedures differ from one system to another, appropriate specifications will be clearly presented. The paper will include requirements to provide a quality joint assembly, meaning the special pre-treatments of the concrete surface. The material to be bonded is cleaned and prepared so that adhesives can adhere better to them.

For the composition and the structural design to lateral loads, the distribution of horizontal lateral forces on vertical structural elements is an important issue, which can become complicated, depending on the considered structural system. In this paper is presented a study regarding the influence of the asymmetry on the response of a mix structure (frame with coupled walls). The structure has 11 floors and is analysed in three different cases of walls positioning, in order to verify their influence on the lateral rigidity and torsional response of the structure.

This paper presents the experimental test results of joints connecting the cold formed thin-walled steel profiles assembled in a pair, back-to-back cross section. The tests were carried on at the Faculty of Civil Engineering and Building Services from Iasi. In the first testing stage there were tested the joints of a frame structural model connected with high strength friction bolts. In the second stage, it was advocated the increase of the profile bearing capacity by introducing some supplementary elements at the flanges; the maximum stresses were expected there and occurred. The specimen is built and modeled as a simply supported beam. In the midspan it is constructed the joint that focuses the research interest. There the load is applied as a concentrated force. The tests were carried on in the quasi-static regime in several load-unloading cycles; in the last stage the load was increased until the model collapsed. The strengthening of the flange has not increased significantly the model stiffness, but the bearing capacity was increased with 20?35% depending on the profile type.

The use of common reinforced concrete shear walls in high rise buildings is sometimes limited because of the large amount of reinforcement localized at the end of the element. A good alternative in avoiding this disadvantage is to use composite steel concrete structural shear walls with steel encased profiles. This solution used for high rise buildings, offers to designers lateral stiffness, shear capacity and high bending resisting moment of structural walls. The encasement of the steel shapes in concrete is applied also for the following purposes: flexural stiffening and strengthening of compression elements; fire protection; potentially easier repairs after moderate damage; economy with respect both to material and construction. Until now in the national and international literature poor information about nonlinear behaviour of composite steel concrete structural shear walls with steel encased profiles is available. A theoretical and experimental program related to the behaviour of steel concrete structural shear walls with steel encased profiles is developed at “Politehnica” University of Timişoara. The program refers to six different elements, which differ by the shape of the steel encased profile and also by the arrangement of steel shapes on the cross section of the element. In order to calibrate the elements for experimental study some numerical analysis were made. The paper presents the results of numerical analysis with details of stress distribution, crack distribution, structural stiffness at various loads, and load bearing capacity of the elements.

The cement and concrete industries are huge. What does this mean in terms of the environment? Concrete and other cementitious materials have both environmental advantages and disadvantages. This paper takes a look at how these materials are made, then reviews a number of environmental considerations relating to their production and use.

There are many ways of classifying construction cost estimates. The most significant of these are the degree of project definition. The degree of project definition is based upon the percentage of completed architectural and engineering designs. It defines available input information to the estimator. Related to input informations, a prudent owner or contractor must associate the “expected accuracy range” The estimate accuracy is an indication of the degree to which the future final (true) cost of construction varies from the estimate prepared earlier. Accuracy is usually expressed as a positive or negative percentage range surrounding an estimated future cost. In this way it defined “classes of construction cost estimates”. This paper represents a proposition to a possible classification of classes of estimates.