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Preventing global warming is a crucial issue of today's development. All the present and future actions should be planned to follow the paradigm of sustainable development, which is defined by the sustainability and decarbonization goals. The above-mentioned approach should be applied in all the economic sectors, out of which buildings constitute one of the most important parts. Moreover, it seems common to aim for the improvement of buildings' energy efficiency, due to the fact, that those actions provide considerable economic and environmental profits. Due to the high share of final energy consumption of buildings, it is necessary to decrease that demand, resulting in reduced greenhouse gasses emissions. In this paper, the Polish residential building sector is examined to improve its sustainability. Some pathways towards buildings' decarbonization are described and evaluated by means of their energy and environmental effects. This study is based on the set of representative buildings of Poland and statistical data, following the Urban Energy Modelling paradigm. Both, single-family and multi-family buildings are analyzed, considering their deep refurbishment. Calculations are performed using the TEAC and Energy Plus software, allowing for comprehensive analyses of the Polish residential household sector. The results presented in this paper might be useful for decisionmakers to define a roadmap towards decarbonization of the Polish residential sector. [ABSTRACT FROM AUTHOR]

In this work, a coupling strategy for the analysis of a tunnel under fire is presented. This strategy consists in a "one-way" coupling between a tool considering the computational fluid dynamics and radiation with a model treating concrete as a multiphase porous material exposed to high temperature. This global approach allows for taking into account in a realistic manner the behavior of the "system tunnel", composed of the fluid and the solid domain (i.e. the concrete structures), from the fire onset, its development and propagation to the response of the structure. The thermal loads as well as the moisture exchange between the structure surface and the environment are calculated by means of computational fluid dynamics. These set of data are passed in an automatic way to the numerical tool implementing a model based on Multiphase Porous Media Mechanics. Thanks to this strategy the structural verification is no longer based on the standard fire curves commonly used in the engineering practice, but it is directly related to a realistic fire scenario. To show the capability of this strategy some numerical simulations of a fire in the Brenner Base Tunnel, under construction between Italy and Austria, is presented. The numerical simulations show the effects of a more realistic distribution of the thermal loads with respect to the ones obtained by using the standard fire curves. Moreover, it is possible to highlight how the localized thermal load generates a non-uniform pressure rise in the material, which results in an increase of the structure stress state and of the spalling risk. Spalling is likely the most dangerous collapse mechanism for a concrete structure. This coupling approach still represents a "one way" strategy, i.e. realized without considering explicitly the mass and energy exchange from the structure to the fluid through the interface. This results in an approximation, but from physical point of view the current form of the solid-fluid coupling is considered sufficiently accurate in this first phase of the research. [ABSTRACT FROM AUTHOR]

A model of the alkali-silica reaction, which takes into account couplings between thermal, hygral, mechanical and chemical phenomena in concrete, has been discussed. The ASR may be considered at macroscopic or mesoscopic scale. The main features of each approach have been summarized and development of the model for both scales has been briefly described. Application of the model to experimental results for both scales has been presented. Even though good accordance of the model has been obtained for both approaches, consideration of the model at the mesoscopic scale allows to model different mortar mixes, prepared with the same aggregate, but of different grain size, using the same set of parameters. It enables also to predict reaction development assuming different alkali sources, such as de-icing salts or alkali leaching. [ABSTRACT FROM AUTHOR]