Jarosław Wójt

The paper addresses an issue of a modernization of farm buildings in case of a replacement of an asbestos roofing. The introduction points out the current state of implementation of the asbestos removal program in Poland and perspectives of its realization in the oncoming years. It has been presented an example of a farm building with a build-up area under 400 m2 where the modernization had been planned during the replacement of asbestos-cement roof panels. A comparison of costs depending on the selected scope of implementation has been made. The costs were determined by averaging the prices offered by local entrepreneurs operating in the construction industry. The quantities of materials and required services have been determined according to the Catalogues of Material Outlays based on the in situ inventory of the facility or on the technical design of the reconstruction, depending on the option. The assessment allowed to state that in the case of replacement of asbestos roofing along with the replacement of the roof load-bearing structure it is justified to consider the possibility of its thorough modernization as a way to restore or increase the functionality of the usable area and space.

The article presents the results of direct research on livestock buildings and their modernization in selected organic farms in the Lublin region. The following counties were selected as the research area: Ryki, Lubartów, Janów and Radzyń. A total of 11 farms were examined. The research was carried out on the basis of a site visit and interviews with the owners. An attempt was made to find a connection between ecological animal husbandry and livestock buildings, perhaps ecological.

The European Union’s initiative to reduce carbon dioxide emissions has paved the way for the exploration of innovative building materials that are environmentally friendly and meet all requirements of durability and strength. These criteria can be met by combining natural resources used in the production of building materials with waste materials that would otherwise be landfilled, having a negative impact on the environment. This study focuses on such materials and presents the results of recent research conducted at the Warsaw University of Life Sciences. The aim was to develop a new generation of materials fully compliant with the principles of the circular economy and sustainable development. Simultaneously, these materials should have no adverse effects on human health and be strong enough to carry the required loads. This study proposes the combination of a natural raw material—in the form of clay—with fly ash from the incineration of sewage sludge to produce a new generation of materials. Several samples were prepared using fly ash from two sources and then were fired at 950 °C. The resulting composites underwent physico-chemical and strength tests. These tests not only confirmed the high strength and durability of the obtained product but also the neutralization of the heavy metals originally present in the fly ash.

The reduction of carbon dioxide emissions, introduced by the European Union, opened the possibility of conducting experimental works on a new generation of materials—ecological and environmentally friendly ones. Such materials include those which combine raw natural resources with waste subject to disposal. The objective of the performed investigations was an assessment of the influence of fly ashes on selected parameters of building materials. The paper proposes a method of the enrichment of clay with fly ash, which would lead to the neutralization of heavy metals in the burnt matrix, possible oxidation of organic substances present in the ashes, or the destruction of pathogens, as well as an increase of the resistance of the clay ceramics to low temperatures. Clay samples were prepared with the addition of the fly ash from three sewage treatment plants. The experiments encompassed investigations of physical and chemical properties of the fly ash, as well as bending strength tests of the beam-shaped samples heated at temperatures of 20, 300, 500, and 700 °C. The beam halves, resulting from the destruction of the samples during these tests, served for testing the compressive strength. The collected results allowed a comparison of the properties of the samples. The obtained test results confirm the possibility of manufacturing a product modified with the fly ash from the thermal treatment of sewage sludge. The obtained compressive strength of the samples amounted 0.3–2.6 MPa.

In the mechanics of concrete constructions, one distinguishes between residual and elastic strains. Cyclic loadings evoke changes mainly in the elastic strains; however, the total strains are decided by the sum of the residual and elastic strains. The knowledge of the ratio between the residual and total strains allows to predict the total deformations of a construction assuming it is made from an ideally elastic material. This paper presents the effect of the load level at the values of the residual strains for beams made of high-strength concretes and subjected to bending. The investigations showed that the share of residual strains for these concretes differed from the share of residual strains for concretes of lower classes. The investigations were made for cyclically loaded concrete samples and ferroconcrete beams for various relative load levels. The ratio between the residual and total strains was presented in the form of a dependence on the relative load level of the element. An important conclusion was that, after the crack formation, the share of residual stresses reduced, along with the increase in the concrete strength and elastic features of the construction which started to predominate.