No abstract

Glass waste is currently produced almost in all developed countries. It is the silicate based waste material which after suitable treatment has found application in many industries and therefore some types of waste glass belong to progressive secondary raw materials. However, the use of this silicate waste material which differ on the basis of an initial use of the glass in its physical and mechanical properties has not been fully explored in the field of building industry – the production of building materials. The replacement of the common filler – quartz sand in the polymer concrete (PC) could be one of the effective possibilities of the utilization of different type of waste glass in the building industry. Mainly for this reason, this work deals with the experimental examining the possibility of using various types of waste glass in the polymer concrete based on epoxy resin.

Currently fillers for antibacterial layers in hygienic operations are mainly primary raw materials, whose properties are verified and well-known due to their long-term use. However, the use of proper secondary raw materials appears to be a good option from an environmental and economic point of view. This work assesses the possible adverse effects of specially treated secondary raw materials in relation to antibacterial properties, chemical resistance and Shore hardness of the antibacterial coating on an epoxy base (AC-E) providing no physiological damage. This coating reliably eliminates the widest possible range of bacteria and yeasts, has sustained effectiveness, consistent functionality over time, provides permanent protection and is suitable for use in healthcare facilities and food processing plants. Two kinds of transparent waste glass (NaSX, VLG) and two types of waste foundry sand (FSC, FSB) were tested, and all fillers were treated so that particle size was below 0.063 mm, including the reference filler (Dorsilit sand). On the basis of antibacterial resistance tests, Shore hardness and chemical resistance, it was assessed that the tested fillers may be effectively used for antibacterial coatings while maintaining the properties of the reference coating. Within the rapid testing of chemical resistance, the surface microstructure of the antibacterial coating was also examined after long-term exposure to aggressive organic and inorganic liquid media. When adding 30% and 35% of the selected waste fillers, the hardness and chemical resistance of the cured coating did not change. The treated waste fillers tested had no negative impact on the antibacterial properties of the coating and were judged to be appropriate fillers in place of Dorsilit silica sand or glass flakes.

The use of suitable secondary raw materials as fillers in progressive, protective agents primarily intended for horizontal concrete construction is very effective not only from the ecological but also from the economic point of view. The impact of using various types of waste glass as fillers on the mechanical parameters of epoxy coatings was experimentally verified. Assessing the dependency of the coating’s chemical resistance on the shape of the used filler’s particles was the main aim of the performed research. A solvent-free epoxy suitable for a chemically aggressive environment was selected for the experiment. These were epoxy coatings filled with a micro filler based on raw materials such as glass flakes and silica flour. Three tested formulations containing fillers with different particle shapes and characteristics were exposed to H2SO4, HCl, CH2O2 and NaOH at concentrations of 5% and 30% and evaluated after 60, 90 and 120 days. The chemical resistance assessment was carried out not only visually but also using a scanning electron microscope (SEM). Thanks to the use of the waste glass as a coating filler, tensile properties and hardness improved, and its use did not negatively affect the chemical resistance and adhesion of the epoxy coatings. It was found that the shape of the filler particles influences the resistance of the coating against a chemically aggressive environment. The epoxy coating containing pre-treated waste windshield glass (shards) showed even better properties than the reference coating.

The paper presents the results and assessment of the properties and capabilities of new types of surface hydrophobic agents for the treatment of fresh and matured surfaces of concrete and other cement-bound layers. Hydrophobisation prevents the premature evaporation of water and thus plastic shrinkage, which inevitably leads to the formation of cracks in cement-based structures. The influence of the new type of hydrophobic agents, epoxy water-based (EWH) and acrylate (AH) containing solvent, on the physical and mechanical properties of the treated concrete samples was assessed, including the adhesion of hydrophobisation on the concrete surface layers. It was confirmed that surface hydrophobisation successfully prevents premature evaporation of water, and thus, plastic shrinkage (concrete treated with EWH_0.3 showed more than two times lower shrinkage than reference concrete). The concrete samples treated by hydrophobisation agents showed higher strength after 120 days (37.5 MPa) in comparison with untreated concrete (32.8 MPa). Different properties were recorded with different types of hydrophobisation agents, including compressive strength after 90 days (31.2 MPa with EWH_0.15, and 35.9 MPa with AH_0.15). Water absorption after 120 days was lowest with EWH_0.3 samples (3.77%), two times lower than AH_0.15 (6.98%). The layer of hydrophobisation agent EWH_0.3 was thicker than AH_0.15, leading to lower water absorption of treated concrete and higher resistance to defrosting chemicals—waste 8.5. g/m2 with EWH_0.3 in comparison to 35.7 g/m2 with AH_0.15. Furthermore, a difference in the hydrophobisation behaviour was shown with blocking of infiltration from the chemically aggressive environment into the concrete substrate. Deterioration of the surface concrete exposed to 10% HCl solution was worse with AH_0.15; but the concrete surface treated with AH_0.15 showed better resistance than the EWH treated surface, when exposed to 5% CH3COOH. Degradation of the hydrophobisation integrity and the loss of cohesion between the concrete and the surface treatment after exposure to acetic acid and hydrochloric acid was observed using scanning electron microscopy (SEM).