Gas Permeability of the Anisotropic Structure of a Frame Made of Concrete with the Addition of a Biocomponent-Application in Livestock Buildings.

The paper presents the results of experimental studies aimed at assessing thermal conductivity, compressive strength, water absorption and capillary action of samples in the form of ordinary concrete (reference sample-B1) and lightweight concrete with the addition of a biocomponent (C100) in the range of 3-31.2% porosity with varied morphology. Gas permeability studies were conducted for porous materials with an anisotropic structure. The measurement results indicate a significant effect of the type of material on thermal conductivity for B1, which is 3.05 W·(m·K)-1 and C100 equal to 0.09 W·(m·K)-1. On the other hand, the highest water absorption is demonstrated by C100, which is 99%, and the lowest by B1 equal to 2%. Tests were conducted for different gas permeability conditions using oxygen (O2), nitrogen (N2) and carbon dioxide (CO2). The basis for assessing gas permeability through porous beds is the gas flow resulting from the overpressure forcing this flow. The highest gas permeability coefficient at a flow resistance of 6 kPa for B1 was 2.7·10-7 m2, and for C100, 2.1·10-7 m2 at CO2 flow. The following issues were identified: scientific, identifying the lack of research on gas permeability testing for anisotropic concrete structures; application, identifying reports of premature failure of concrete structures in livestock buildings due to the effects of toxic substances. The novelty in the article is the indication of the gas permeability model and the performance of a comparative analysis (multi-criteria analysis) based on diagnostic features. In the hierarchical decision-making structure, gas permeability was used as one of the evaluation criteria, which can be assessed as a stimulant or destimulant depending on the climatic zone. The permeability of gas media is one of the features that allow for assessing the suitability of materials, among others, for small-sized prefabricated wall systems-the durability of both the element itself and any reinforcing inserts depends on permeability. The aim of this article was to compare the physical and functional properties of materials, such as thermal conductivity, water absorption, capillarity and gas permeability, in relation to the material composition. The research was of an application and engineering nature, focusing on macroscale functional parameters that are important from the point of view of the practical application of the tested building composites. The scientific problem is to indicate the lack of scientific research on the study of gas permeability in anisotropic concrete structures in livestock building conditions. The engineering use of hempcrete indicates its usefulness in various structural elements of livestock buildings.