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In last years, recycling has become a strategic factor in global politics, a vital component and a cost factor for economic development and the progress of society as a whole, generating a number of major global concerns. Exceeding twice the sum of all materials used in construction, annual concrete consumption around the world amounts to approximately 10 trillion tones being by far the most used building material and the partial or total replacement of a component of its mass with recyclable waste has a major pos...

The handling and disposal of voluminous sludge produced from water treatment plants poses difficulty to environmental scientist and engineers. In fact, its environmental friendly management and disposal is challenging task and requires careful consideration. In this study, sewage sludge ashes were examined as potentially supplementary cementitious materials. The raw sewage sludge was provided by two different municipal waste water treatment plants, coming from Poland and Greece respectively. The calcination of pre...

The basic contractual instrument among all involved parties of construction projects in the Czech Republic is a contract for work according to the Civil Code of the Collection of Law of the Czech Republic. The contract is further supplemented by provisions based on long-term business experience and needs of contractual partners. An essential part is the type of price, its amount and the method of determining or adjusting the price. For green constructions in general and green buildings in particular it is customar...

The use of weak local soil as well as the recycling of existing worn-out structures such as old road pavements using micro particle road binders are a beneficial ecological solutions. Parameters of the soil stabilized with binders significantly affect the load bearing capacity and durability of the built structures. Mechanical parameters of the soil are therefore needed in the analysis and design of soil structures. Determination of the exact value of these parameters in indirect tensile test is related to the nee...

The aim of this study is to explore the possibility of recycling waste materials of brick aggregates (BA) and demolition concrete aggregates (DCA) in the self-compacting concrete (SCC), by studying these fresh and hardened properties. A reference mixture based on natural aggregates (NASCC) and six mixtures incorporating recycled brick aggregates (BASCC), recycled demolition concrete aggregate (DCASCC) and combination of recycled brick and demolition concrete aggregates (BDASCC), as replacement of natural aggregate...

The building sector is interested in developing new types of structures capable to resist seismic loading. There is introduced a new structural detailing of mix steel-concrete structures. The innovative design consists in use of the precast concrete slabs and steel frames, assembled by post-tensioning, of the prestressing procedure for the steel members and also a different column-beam connections having resilient characteristics. Each of the listed features is also special. The prestressing reinforcement is locat...

This contribution results from the experiments conducted in the experimental gallery in the limestone pit. The gallery consists of three horizontal parts, two of them are parallel. The premises of the experimental galleries are used for testing and research in the area of explosion prevention. The partition masonry walls were built inside the gallery and they were subjected to the blast load induced by air-gas mixture. The paper introduces the principles for determining the dynamic load and for its simplification,...

The primary aim of earthquake resistant design is to prevent building collapse during the seismic event, but severe earthquakes have a low probability of occurrence during the life time of the structure, therefore in contrast to traditional structural design in earthquake design, structures are permitted to work in post-elastic domain under seismic load. It would require a large lateral stiffness of the structure and an expensive resisting system to design the building to have an elastic response. Because of these...

Sustainable design attempts to be perceptive to the environmental impact of the building project at each construction stage by evaluating the site, the embodied energy of the selected materials, as well as the proper construction techniques, adjusted to the local conditions. Moreover, physical hazards (flammability, corrosion) and/ or health hazards (toxicity, irritations) of the materials are especially important not only for the construction workers, building owners and occupants, but also for the environment, c...

The presented paper deals with the design and examination of steel towers of electrical transmission lines with circular or polygonal cross section. Structures of this kind are a safe and reliable option when selecting the appropriate structural solution, but nevertheless often remain omitted due to difficulties with design methodology. The cross sections of conical towers are in majority of cases categorized as class 4 sections. Being classified as such, they are in certain loading situations considered as shell ...

The article discusses the need to introduce energy management of municipally-owned buildings provided by the concept of Smart Cities. Cities use many buildings. These buildings also have a different nature of use, such as offices, schools, social care homes, etc. All these buildings consume energy that needs to be monitored and regulated. Energy management needs a large amount of relevant data on these buildings together in one comprehensive system. When planning building revitalization, it is necessary to have su...

This article is referring to a short study regarding the energy efficiency status in retail industry in Romania, in particular an analysis of the big sizes commercial buildings in this matter. It contains data which will allow us to compare an existing building with the industry norms in terms of the energy consumption and energy costs. Additionally, there are some recommendations provided to be taken care of in the near future for controlling energy better, using energy in a more efficient way and reducing avoida...

This article is the continuation of the paper published at the conference SGEM in 2016. European product standards generally do not specify the qualitative requirements for individual product characteristics. EN 14695:2010, which deals with the waterproofing of concrete bridge decks, is not an exception. The national standard CSN 736242:2010 sets quality requirements for bitumen sheets. The type of the modification of bitumen coating is not considered in quality requirements of this standard - the mass modified by...

Nowadays concrete is the worldпїЅs most widely used building material. A decisive constituent is cement, which causes in production nearly 10% of the worldпїЅs CO2 emissions. Ultra High Performance Concrete (UHPC), a new high-tech concrete with an outstanding compressive strength of 4 to 6 times the strength of standard concrete (NSC), is the most advanced building material in reinforced concrete construction and increasingly used in different countries all over the world. Due to its high compressive strength, bui...

The global level of urbanization is growing. Some estimates indicate that till 2030 the degree of urbanization will reach 83% in economically developed countries. In this context, large urban areas are already facing with problems due to water and air pollution, noise pollution, forming "heat islandsпїЅ, energy consumption, overload of rainwater collection systems and human health degradation. In this paper are presented the benefits of green roofs and the contribution they play in solving problems in urban areas....

The correct design of the construction equipment objects and their usage plays an important role in the overall efficiency of the construction with regard to the execution time, the resulting price, performance of workers on the construction site and use of deployment mechanisms. During the construction is the possibility of using alternative sources in the design of construction equipment, which may contribute to the overall efficiency of the construction. The article gives an example how to proposal a suitable t...

This study of an alloyed steel with Cr, Mo which has an important content of aluminum (0.9,пїЅ1.2)%, unconventional treated in magnetic field, is attractive because of the increasing of the durability and the wear resistance along with the improvement of the corrosion resistance. Thermo-magnetic treatments applied before the thermo-chemical treatment has consequences such as the improvement of the mechanical properties of this material. The micro-hardness of the superficial layers has been increased after the unco...

Metakaoline is a relatively new pozzolanic additive, obtained by calcination of kaolin clay at relatively low temperatures. Themselves pozzolanic additives are known for a very long time. Currently, there is interest to pozzolanic materials again, because their usage allows reducing the total environmental impact and cost of cement. The influence of metakaoline on hydration and hardening of cement was studied. The usage of metakaoline as the additive to cement composition increases the strength of cement stone. Be...

The buildings energy performance is becoming increasingly important, because of environmental restrictions connected with CO2 emission and rising costs of fuel end energy. Respecting sustainability issues, design of buildings with improved thermal properties and optimum energy performance is preferred, whereas specific attention has to be paid not only to the design of building envelopes, but also to the thermal insulation of buildings subsoil. To obtain buildings with high thermal resistance and sufficient therma...

Solar energy technologies have been in continuous development to cope with the increasing demand. Since the solar energy supply is variable in daytime and zero at night, a considerable amount of solar energy should be stored during the daytime to meet the demands at night. In any solar energy system, a storage unit is required because of the non-constant nature of solar energy; at certain times, only a very small amount of radiation or no radiation is received. This introduces the idea of using Phase Change Materi...

In the present days the need of obtaining good and economical solutions for thermal insulation of the new and old buildings, it is compulsory. This fact leads to the need of developing new insulation materials all over the world. Such a new material it is tasted now in the west part of Romania, named Thermoconfort Plus B. The panels are made by polyurethane rigid foam combined with polyisocyanurate which is laid out between two sheets of vapour barrier material. The edges of the panel are factory manufactured to a...

The possibility and practicability of usage aluminiferous waste in the production of aluminate cements were studied. Aluminothermic slag, calcareous component and alumina in row stock was correlated for different compositions of aluminate clinkers. Clinkers were making by electric-arc melting at temperature 1600 ??. There was found a difference in mineral composition under conditions fast and slow cooling aluminate melts. In case of fast cooling main phase was calcium bialuminate and high glass-like phase content....