Lime quartz samples in which ground quartz sand was gradually substituted with waste glass powder (GP) were obtained under hydrothermal conditions to determine the influence of GP addition on the microstructure (observed by SEM), phase composition (analyzed by XRD), and compressive strength of autoclaved building materials. An additional series containing analytical grade NaOH and no GP was formed to evaluate the effect of sodium ions on tobermorite formation and its impact on the mechanical properties of the samples. GP addition hindered the formation of tobermorite during autoclaving. Instead, a higher amount of an amorphous and semi-crystalline C–S–H phase formed, leading to the densification of the composite matrix. Nevertheless, tobermorite-like structures were found during both XRD and SEM analyses, proving that the presence of small amounts of Al³⁺ ions allowed, to an extent, for the stabilization of the phase despite the high sodium content. The compressive strength values indicate that the presence of alkali in the system and the resulting formation of additional portions of C–S–H have a beneficial influence on the mechanical properties of autoclaved composites. However, the effect fades with increasing glass powder content which, together with a slight expansion of the samples, suggests that at high sand substitution levels, an alkali–silica reaction takes place.

Aim of study was to verify the effect of temperature on the pozzolanic reactivity of thermally activated attapulgite and sepiolite samples. Activation temperatures were selected: 650, 700 and 750 °C for attapulgite and 800, 825 and 850 °C for sepiolite. Content of pozzolanic reactive SiO₂ and Al₂O₃ after thermal treatment and the amount of Ca(OH)₂ consumed in the pozzolanic reaction were measured. It should be noted that a higher activation temperature improves the reactivity of attapulgite and sepiolite. The upper limit for the increase in the pozzolanic reactivity of these materials is the formation of enstatite and the deactivation of silica. In addition to reactive decomposition products, series of minerals formed in the reactions of attapulgite and sepiolite with impurities present in them are also observed.

The continuous search for new sensing materials with high recognition capabilities is necessary to improve existing analytical procedures and to develop new ones. Natural glassy carbon and polydimethylsiloxane were shown to be used for the preparation of carbon paste electrodes to employ them in new, voltammetric, green-chemistry-friendly electroanalytical procedures aimed at evaluating the antioxidant capacity of plant extracts, dietary supplements, and hydrolats. The developed electrodes provided well-shaped and reproducible voltammetric signals (RSD = 1%) of the oxidation of epigallocatechin gallate, the main component of many plants and plant-based formulations with antioxidative activity, in the 1–12.5 µM range (DPV mode, LOD = 0.08 µM). If needed, the performance of new carbon paste electrodes can be further enhanced by the introduction of trivalent rare earth oxides to carbon paste to increase its active surface, facilitate electron transfer, and improve the resolution of recorded signals.

The cement mixtures used in the studies were prepared by partial replacing of Portland cement CEM I 42.5R with a mixture of blast furnace slag and siliceous fly ash. The purpose of the study is to verify the properties of the ternary cements included in the PN-EN 197-5:2021 standard as CEM II/C-M and CEM VI cements. Their hydration heat, compressive strength, phase composition and microstructure were studied. The higher blast furnace slag content results in a greater reduction in the rate of hydration heat evolution and cumulative hydration heat evolved and lower and delayed effects related to Ca(OH)2 and alkalis presence. More blast furnace slag gives a cement mixture of the lower strength class according to the PN-EN 197-1:2012 standard. With the addition of 50 % blast furnace slag, none of the strength classes is achieved. Strength reduction may be due to the discontinuity in microstructure observed in SEM studies.

In the study, cement mixtures containing granulated blast furnace slag (GBFS) and siliceous fly ash (SFA) were tested, including those corresponding to special cements according to the PN-B-19707: 2013 standard. Measurements included the period of development of standard strength (up to 28 days) and concerned the compressive strength, linear changes and phase composition of cement mixtures. Furthermore, an evaluation of the microstructure of cement mortar was carried out by SEM. The mixture of composition CEM II/C-M (S-V) satisfies the requirements of the 32.5R or 32.5N strength class, whereas that of CEM VI (S-V) is of the 32.5N strength class, as opposed to stronger mixtures richer in Portland clinker.