Maciej Szeląg

Hydrophobization of Lime Composites with Lignocellulosic Raw Materials from Flax

ABSTRACT The aim of the study was to evaluate the possibility of applying lime binder together with flax fibers and straw to the production of wall materials. Properties of the composites were modified by additives and admixtures. The following laboratory tests were performed: the analysis of the physical characteristics, compressive strength, a water droplet absorption test, water absorption of hydrophobized and standard samples, drying time, and analysis of the structure using scanning electron microscope (SEM). In the paper, there was examined the effectiveness of two formulations differing in the degree of hydrolytic polycondensation, viscosity, and concentration, as these are the factors that determine the final impregnation effect.

Physico-Mechanical Properties and Microstructure of Polymer Concrete with Recycled Glass Aggregate

The paper presents an analysis of the possibility of using glass waste from worn out lighting materials as an aggregate for a polymer concrete. Glass waste was obtained from the company utilizing glass lighting elements, which was then subjected to crushing. The aggregate obtained was subjected to the tests of basic features, which were compared with aggregates that are traditionally applied to concretes. The next stage of the research program was the production of a polymer concrete that contained glass aggregate. Several types of mixtures were prepared in which glass waste was combined in various proportions with traditional sand–gravel aggregate. As a part of the research, the basic physical and mechanical characteristics of polymer concretes were determined. The microstructure of composites was also analyzed using a scanning electron microscope. The results of the research have shown that the aggregate obtained from glass waste can be successfully used for the production of a polymer concrete. The most beneficial physico-mechanical properties were obtained for a composite in which glass waste was used as a 50% substitute for traditional aggregate.

Development of Cracking Patterns in Modified Cement Matrix with Microsilica

The paper evaluates the cracking patterns created on the surface of a microsilica-modified cement matrix, which has been subjected to exposure at elevated temperatures. To do this, image analysis techniques were used, and the structure of the cracks was described by the stereological parameters. Four series of specimens were tested and in two of them, microsilica was used as a 10% replacement for the cement content. Using the theory of dispersion systems, the factors affecting the cracks’ characteristics were identified. Additionally, the development process of cracking patterns due to the thermal interaction was schematically modeled. In addition, the analysis of the local microstructure of the cement matrix was performed by means of a scanning electron microscope and energy dispersive x-ray spectroscopy.