DETERMINATION OF THE CHARACTERISTICS FOR A MULTILAYER WALL'S STRUCTURE WITH APPLICATION OF QUADRATIC PROGRAMMING TOOLS

High requirements for the energy efficiency of residential construction projects being built, a high level of competition between building organizations, as well as a wide variety of applied materials and technologies determine the high importance for solving of the problems connected to determination of the characteristics of external multilayer wall structures. On the basis of the results received during the analysis of the relevant scientific developments, it has been concluded that the existing tools are limited in terms of taking into account thermal performance indicators as criteria for determination of the optimal values for the characteristics of the structure – particularly, the thickness and thermal conductivity of the structural layers. The expediency of conducting of the research aimed to the development of a tool for the determination of the characteristics for a multilayer wall structure on the basis of quadratic programming has been substantiated.

IMPROVEMENT POTENTIAL FOR SOUND INSULATION OF SINGLE- AND MULTILAYER WALL PANELS

Relevance: Acoustic comfort in residential, public and industrial buildings. Existing types of wall panels often do not provide the required noise control.Purpose: Investigation of the improvement potential for sound insulation of single- and multi-layer wall panels having finitegeometric dimensions with diffuse sound lowering. Design/methodology/approach: Consideration of the sound propagation through the wall panel based on the theory of selfcoordination of wave fields developed by the Prof. Sedov‟s scientific school.Research findings: Analytical equations for calculating the limiting sound insulation of the wall panels determined by the inertial sound propagation. The improvement potential for sound insulation of single- and multi-layer wall panels having finite dimensions. Comparison of theoretical and xperimental results. It is shown that single- and multi-layer wall panels of finite geometric dimensions have improvement potential for sound insulation, which is determined by the ratio between their own and limiting sound insulation.Practical implications: Wall panel design must take into account the improvement potential for sound insulation. The sound insulation of wall panels is improved without increasing their mass and thickness. This is of great importance for design solutions for wall panels of civil and industrial buildings.Originality/value: The proposed method shows good agreement between experimental data and theoretical calculations. The improvement potential for sound insulation at the frequency level locates near the resonant frequencies, namely: near-boundary frequency of the full spatial resonance for single-layer wall panels; near-resonant frequency of the mass-elasticity-mass panels and near-boundary frequency of the full spatial resonance for multilayer wall panels and panel linings, respectively.

Compositional Characterization and Chronology of Roman Mortars from the Archaeological Site of Arroyo De La Dehesa De Velasco (Burgo De Osma- Ciudad De Osma, Soria, Spain)

This study characterises the mortar materials used in the construction of walls and floors at the Arroyo de la Dehesa de Velasco site, located near the Roman city of Uxama Argaela (the modern Burgo de Osma—Ciudad de Osma, Soria, Spain). Multilayer mortars have been characterised by petrographic, mineralogical (X-ray diffraction and scanning electron microscopy with energy dispersive analyses and geochemical analysis (X-ray fluorescence). Additionally, radiocarbon dating of the mortar binder fraction was performed in order to establish the chronology of the building in the absence of other archaeological chronological records. The results showed that similar siliceous aggregates and lime binders were used in the fabrication of multilayer system mortars. Some multilayer wall mortars show ceramic fragments or brick powder to produce hydraulic mortars and improve the resistance to moisture. The raw materials used for the construction of the site were of local origin and the construction was built during the first century BC, according to radiocarbon dating.