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With the growth of the construction industry market there is an urgent need to evaluate the use of building materials from the sustainable point of view. Product stage of construction materials has a significant negative impact on the environment. This work represents environmental assessment of the construction materials of a low-rise residential building located in the temperate climate zone. To conduct such an analysis, we used a comprehensive methodology, product life cycle assessment (LCA), complying with international standards ISO 14044 and ISO 14025. The global warming potentials were calculated for the building life cycle product stages (A1-A3) in the equivalent of the carbon dioxide emissions (CO2e). It was found that external walls have the greatest negative impact on the environment compared to other building elements. Production of construction materials for external wall structures is responsible for 45 % of the total CO2e emissions. Based on the performed calculations, alternative options for exterior wall construction are proposed. Heat losses were calculated for each type of enclosing structures, as well as greenhouse gas emissions from burning fuel for heating the building. It was found that an aerated concrete wall with ventilated facade has the least negative impact on the environment, even though heating a building with such an enclosing structure requires more energy than other wall options. Environmentally reasonable approach of the enclosing structure selection allowed a reduction of greenhouse gas emission by 16.7 %, from 402.85 tons to 335.65 tons CO2e.

This paper considers microclimate to be one of the main contributors to thermal comfort in educational buildings. The influence of microclimate on well-being and productivity is considered. The role of microclimatic parameters is assessed from the perspective of building design, focusing on approaches to regulating these parameters. We also describe the formation of microclimate and the factors directly affecting it. The state of the microclimate of classrooms of an educational institution was analyzed, providing estimates of people's real thermal sensations. The microclimate was assessed by the Fanger method. The PMV and PPD comfort indices were calculated for this purpose. The calculations were carried out thrice, i.e., based on the data obtained by using measuring equipment, based on the data from the survey and based on a SolidWorks model. Calculations in the program were carried out to validate the measured values and visualize the process of the distribution and localization of comfort indices. The results confirm that the indoor microclimate was generally favorable, and the PMV values obtained from the survey of people's real sensations of thermal comfort were higher than the calculated PMV values. It was established that the PMV and PPD values corresponding to the largest deviations from the norm were as follows: −0.74/17% (PMV/PPD) for the calculation based on the real values of microclimatic parameters and 0.70/15.3% (PMV/PPD) for the calculation based on people's thermal sensations. For applying the Fanger method for thermal comfort analysis in an educational institution in St. Petersburg, we upgraded the procedure, introducing a questionnaire survey. The mean PMV values calculated by the Fanger method were 0.16 lower than the PMV values obtained by the survey. [ABSTRACT FROM AUTHOR]

Application of natural plant additives allows improving thermal and mechanical properties of concrete composites. Environmentally friendly wood waste is gaining particular popularity. One of the promising filler types for concrete is hogweed chips. In this study, the flexural properties of two types of concrete composites reinforced with plant additive samples, including a large additive of hogweed 50 mm long and a medium additive of hogweed 25 mm long were examined. In addition, a composite sample reinforced with short polypropylene fiber was produced. Each series of concrete composite consists of three samples. A three-point bending test was conducted to determine the reinforcement efficiency of the manufactured composites. Instron 5965 (USA) unit helped determine maximum load and normal stress. The results showed that the flexural strength of composites with long additive pieces is greater than that of the other samples. The increase in flexural strength was 5% and 25% for composite made of short and long pieces, respectively. The interaction mechanism between wood additives and cement matrix in the composite was analyzed by means of optical microscopy. The surface formations were found to significantly affect the bonding properties of the concrete and the hogweed.

Thermal stability of the enclosure structures is one of the most important objective in the building design. Thermal processes in the wall depend not only on the internal and external air temperature, but also on many other factors. Therefore, complexity of this process make heat conservation in the room to be an actual problem. This paper presents dependence between thermal stability of the enclosure structure and its design. It was shown that thermophysical characteristics of materials directly affect the thermal processes in the wall. For the research, three frequently used types of enclosure structure in Russia were taken. For each wall was found the average temperature and cooling time. As a result, it was found that the higher values of thermal conductivity, specific heat and material density are, the higher average temperature of the wall is.