Concrete is a highly alkaline material; therefore, the presence of organic acids (acetic, butyric, lactic) from agricultural sewage constitutes a threat to the concrete and the environment. The investigations were aimed at simulating the influence of highly concentrated organic acids on concrete elements of livestock buildings. Cubic samples 100 × 100 × 100 mm of the ordinary concrete were immersed in 10% acetic acid for 270 days. Then, the compressive strength and mass decrement of the samples were determined as well as using SEM images and a 3D-profilograph to profile the surface roughness and depth of changes evoked in the structure of the samples by penetrating acid. The results were compared with those for a control sample (not subjected to the effects of aggressive agents) as well as for samples placed in a neutral and alkaline environment. The compressive strength of the samples stored in the acidic environment was 22.23% lower than that of the control sample, whereas the compressive strength of those samples stored in an alkaline environment were 44.27% higher. Conclusions from these investigations can be of innovative importance in the preparation of environmental impact reports, which are necessary for obtaining permission for the construction and use of livestock buildings, and afterward in the reduction of the impact of these buildings on the environment and surface and underground water resources.

In recent years, because of the continuous expansion of urban areas, an increased necessity to isolate historically polluted sites by means of artificial, flexible, low-permeability barriers has emerged. Moreover, due to cost and efficiency considerations, various combinations of materials that fulfill the previously stated requirements have been proposed. On the basis of a literature review, this paper analyses the relationships between water, cement, and bentonite, and the physical and mechanical properties of the resulting material created in combination with standard sand introduced in the mixture using a ratio of 2:1 with respect to the solid part of the mixture (cement and bentonite). The quantity of standard sand was established following previous research conducted by the authors. The relation between water, cement, and bentonite is analyzed through properties such as viscosity, permeability, and undrained cohesion, and the representation of mixtures and their corresponding parameters was carried out using a ternary diagram. This paper provides a graphical approach to finding the optimum water/bentonite/cement mixture required for barrier design, taking into account permeability, undrained cohesion, and mixture viscosity.

Contact of concrete with aggressive factors, technological structures, reduces their durability through microstructural changes. This work presents the results of research on determining the influence of post grit chamber sewage and sewage from the active sludge chamber in three different environments, i.e., acidic, neutral, and alkaline, on the structure and compressive strength of concrete. Compressive strength tests were carried out after 11.5 months of concrete cubes being submerged in the solutions and compared. To complete the studies, the photos of the microstructure were done. This made it possible to accentuate the relationship between the microstructure and performance characteristics of concrete. The time of storing the cubes in both acidic environments (sewage from post grit chamber and active sludge chamber) has a negative influence on their compressive strength. The compressive strength of cubes decreases along with the time. Compressive strength of cubes increases with increasing pH of the environment.