One of the most important parameters of comfort in a building is acoustic comfort for which designer engineer typically given little or no attention during project planning and design. The purpose of this article is to highlight the noise produced by boilers in a technical room of a faculty in Romania. Different measurements were performed for the gas flow and noise level in the boiler room. The measurements resulted in several values of the noise level for different thermal loads of the boilers. The result obtained confirm that noise level depends on the thermal load and that increase of thermal load is directly proportional to the noise level inside the plant room. After the measurements, the values of the noise level were processed and compared with literature predicted values and the maximum limit values from the Romanian norm. The results of this article highlighted the noise produced in a technical space of a modern power plant, correctly installed and calibrated. This study can by used by design engineers and all participants in designing and installing equipment in a new educational building, but also in an existing building to meet the comfort conditions of the students.

.The purpose of our research is to test the effectiveness of some basic configurations of natural ventilation on the thermal comfort of occupants for different climates. The study focuses on the Algerian climate. Seven cities were selected from the new climate zoning of Algeria proposed by [1]. To evaluate the potential of the selected configurations and given the diversified nature of the Algerian climate, the study will focus on the mid-season period that includes the months of May September and October and the summer season for the months of June, July and August. The study was carried out through numerical simulations using the TRNSYS software coupled with the COMIS aeraulic software. The results of the simulations showed the contribution of natural chimney ventilation caused by the stairwell to improve occupant comfort Its integration, however, requires a judicious and permanent control to guard against the falls of temperatures or the risks of overheating.

The durability of ultra high performance fiber-reinforced concrete (UHPFC) made from local raw materials has been studied in this manuscript. An experimental study was carried out on the best variants of UHPFC using finely ground dune sand as ultrafine. The UHPFCs studied were developed from Portland cement (PC), dune sand (DS), fine sand (FS), metal fibers (MF) and superplasticizer additive (SP). The results show that it is possible to manufacture a more ductile and durable fiber concrete of 41.96 and 35.28 MPa for flexural tensile and 95.5 and 85.36 MPa for compressive strength for UHPFCs made from dune sand and immersed respectively in two chemical solutions concentrated at 5M hydrochloric acid and barium sulfate for one year. The manufacture of a concrete based on local raw materials with good mechanical properties and durability can reduce the consumption of cement.

This paper presents a viable solution for the practical realization of a laser cutting and engraving device that can be operated manually or automatically. The proposed device is portable and is ideal for simple and fast engraving of different types of materials. The device can engrave wood, cardboard, plastic, leather, plastic, but it cannot engrave glass, ceramics, metal, stone, marble. It is a small device that fits on any desk and can be easily transported. The transmission of the information from the engraving process can be done through a computer program or the engraving can be done manually with the help of a joystick. Under these conditions, it becomes possible to manually and automatically control the laser cutting or engraving device. Given this aspect, the paper focuses on both the management of the automatic control of the engraving device and the realization of a manual electronic control with a joystick. The 1000mW power of the laser is sufficient for projects such as customizing phone cases, personalizing small objects, making cut invitations or postcards, signing design objects. The machine cannot replace a professional engraving machine with much higher power, capable of cutting or engraving any kind of material.

In the context of sustainable development, the use of renewable energy sources and the decrease of greenhouse gas emissions have become global priorities. Geothermal energy represents an important potential for many countries, including our country. If the exploitation of thermal energy has a relatively widespread, the production of electricity is less developed, even if there are countries that cover a significant part of the electricity demand from this resource. In this paper, the authors aim to present the main technical solutions that produce electricity from geothermal sources, but also present some topological models for integrating the obtained electricity in the public network.

The aim of this work is to examine the thermohydric behavior of a building made of compressed stabilized earth bricks (CSEB), by testing its effectiveness in stabilizing the quality of indoor air, compared to four conventional materials. The study is carried out using TRNSYS-COMIS software with its Buffer Storage Humidity Model for three types of climates: desert, Mediterranean, and dry and cold semi-arid climate. The results highlight the contribution of the CSEB material in regulating the indoor relative humidity of buildings, also in limiting the effects of condensation thanks to its adsorption effect.

The exploitation of clays in the cement sector creates a great influence on the geological monuments as well as on the general geological environment. In this context, this article aims to valorize kaolin from southwestern Algeria in sustainable concrete and to exploit their deposit site as a landfill. In order to obtain metakaolin, this kaolin is subjected to a thermal transformation controlled by an apparatus designed to test the ecological efficiency of this material. Subsequently, a mass substitution of 10% of cement with metakaolin in concrete was made for the study the performance of this new concrete.

With the diversity of concrete quality, sand has taken a big place in the composition of sand concrete. However, reinforced concrete based on sand is undergoing experimental tests and validation tests, and its cracking in this concept has become a very paramount parameter when sizing this material. In this context, this work of an experimental nature, has for main objective to study the cracking of an element of reinforced concrete based on sand by the variation of the spacings of cracks using a reduced model in reinforced concrete.

This study analyses the contribution of wood chipboards combustion to a natural scale fire that manifests in a confined space. Wood is of particular importance in the development of fire in buildings, because it is widely used in building’s frame structures, for cladding, floors or furniture objects. This study starts from the description of the physical and chemical phenomena occurring during the wood combustion process and continues with the presentation of the fire performance under final use conditions. The results obtained from the fire test of the wood chipboards for ISO 9705 and SBI test methods are presented, also. The study ends with the natural-scale simulation of the wood chipboards contribution to the development of confined space fires, by using the BRISK fire simulation program, based on the two fire test methods and the two fire scenarios. There are two fire scenarios: 1st. The test room is not cladded with interior lining material, its walls made of concrete with a thickness of 100 mm and 2nd. The test room is cladded with 12 mm thickness wood chipboards used as interior lining material. Thus, a comparative analysis of the temperature of the upper layer of hot gases and of the ceiling results from the use of the B-RISK program in the two test situations and methods is obtained. Following the analysis, some recommendations are given that can improve fire safety in the case of confined spaces containing wood in the form of chipboards.

In this paper is it presented functional modelling of an unconventional system composed by fotovoltaic panels which are producing electric energy to drive the compressor of a heat pump to produce termal power for central heating unit of a building or to be used for daily hot water. Can be seen in tha paper the corresponding equations to evaluate electrical power from sollar cells and equations to establish the dynamic termal power given by heat pump to final costumer. At the end will be realized an energetic analyze and economic aspects to conclude the implementation of such unconventional systems.

One of the alternatives of designing new buildings but also for interventions to existing buildings is based on the use of the Tuned Mass Dampers (TMD). Given that they are effective only in high rise buildings, case studies have been carried out for buildings with 10, 20, 30 and 40 levels, having 3 different types of shapes in plan (circular, square and rectangular) and two types of structures (reinforced concrete frames and reinforced concrete dual systems). Comparisons were made between the structural responses obtained for the calculation models corresponding to the buildings with and without using the TMD.

The objective of this paper is to present aspects related to: corrosion of metals covered, and not covered with zinc in the soil of Timi?oara (grounding electrodes of a grounding installation related to Electrical Installations of Constructions), analysis of soil parameters, prototype electrodes, electrical, microbiological measurements and mathematical prognosis analysis-prediction, materials, and dictionaries of related terms. Another aspect presented in this material are the measurements related to the spectrum of the oscillograph electromagnetic field of the grounding electrodes, which are covered, and not covered with zinc.

The first aim of this study is the use of marble waste powder as a partial replacement with cement (CEMI 42.5) in concrete in order to reduce greenhouse gas emissions results in the cement production and consequently on the manufacturing concrete with less environmental impact. Moreover, the carbonation phenomenon influences significantly the durability of reinforced concrete structures, in this context, the second aim of this work is the study of the effect of the accelerated carbonation on the durability of concretes formulated with the cement containing the marble waste (MDP) with different percentages. For this purpose, four concrete mixtures containing 0%, 10%, 15%, and 30% MDP as cement replacement by weight basis have been prepared. These mixtures of concretes were submitted to accelerated carbonation to study their durability against this phenomenon. The series of tests are conducted to study the effect of 10%, 20% and 30% replacement of cement with marble powder on carbonation depth and compressive strength and compare it with the conventional concrete. The result of this present investigation indicates that the carbonation depth increases with the increase of the rate of the replacement of cement with waste marble powder (10 % to 30%) and the compressive strength decreases slightly with the increase of replacement. the compressive strength remains within the acceptable range of M25 concrete.

In the fire safety design of buildings, it is common practice to consider a smoke and heat exhaust ventilation system. The choice is made between either natural ventilation or a mechanical ventilation system. In case of a fire, the main requirement for building designers is to save users. For the safety of users during a fire, low temperatures, high oxygen concentration and good visibility for a certain period must be ensured. Three different cases of ventilation in case of fire were analyzed in this study: mechanical ventilation (CASE1) and natural ventilation (CASE2- wall hatches and CASE3- roof hatches). The results of an experimental study were used to validate a numerical model (CASE0- no ventilation system) using FDS software. The action of the fire in a room with an area of 18(m2) has been studied. Indoor temperatures, oxygen concentration and visibility are determined and used to establish the performance of different ventilation system. The three parameters play an important role in assessing the environmental conditions necessary to save users. The study shows that natural or mechanical ventilation in case of fire considerably improves the evacuation conditions, saving users lives. Both types of ventilation ensure good performance in the situation of a correct dimensioning and designs.