This article discusses construction waste and its management in the territory of Croatia. In order to better understand the concept of waste, the first part of this paper discusses its origin, characteristics, and categorisation. In addition, it mentions special categories of waste defined within Croatian borders. All members of the European Union are encouraged to adopt a circular economy approach to manage these various types of waste. Furthermore, the article emphasises the necessity to construct legal landfills in addition to building management centres, recycling yards, and transfer stations, in order to reduce the formation of wild landfills, which result from irresponsible waste disposal. The second part of the article provides a detailed description of construction and demolition waste. In addition to the types of occurrences and the associated degree of hazard, a categorisation system is used. This system includes records and key numbers, and allows finding the appropriate species in the database with the corresponding key number. Modern technology has made it possible to recycle all types of waste, including construction waste, into secondary raw materials. Proper management is essential to achieve this goal. The first step involves prevention, diversion or conversion of waste into a resource. When these options are not possible, one of the recovery processes should be employed. Managing Construction Waste also provides a comprehensive explanation of recycling, which is given significant attention. The article concludes with an overview of the Republic of Croatia’s system for managing construction waste, which lags behind more developed countries, as well as offers examples of best practices and possible improvements.

In this study, silver nanoparticles were synthesised through an eco-friendly process without the use of organic or toxic solvents. The synthesis was carried out with green tea serving as both the reducing and stabilising agent, using 1 mM silver nitrate solution and distilled water as solvent. Catechins present in green tea were involved in silver ion reduction. Characterisation of the colloidal silver was conducted using UV-Vis spectrophotometry, FTIR spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM). UV-Vis spectrophotometer confirmed the presence of silver nanoparticles through the observation of surface plasmon resonance, while DLS and SEM analyses were employed to assess nanoparticle size, shape, and sample uniformity. DLS analysis revealed particle distribution in colloidal silver with nanoparticle sizes ranging between 32 and 95 nm. FTIR analysis confirmed the presence of polyphenols, particularly catechins, in green tea, emphasising the role of OH groups in the reduction of silver ions and nanoparticle synthesis. SEM analysis showed that the silver nanoparticles were spherical, with an average size of 62 nm. The antibacterial efficacy of the silver nanoparticles was tested against Escherichia coli NCTC 13216 and Staphylococcus aureus ATCC 25923. The results demonstrated an antimicrobial effect of green tea-synthesised silver nanoparticles against both bacteria at specific concentrations.

This work examines the influence of zeolite saturated with zinc (SZ) on the early hydration of Portland cement. The measurements and results indicate that the microcalorimetric method allows continuous observation and determination of SZ’s influence on kinetic processes in the early stages of hydration. According to the total heat released after 48 hours of hydration, higher SZ content results in lower heat values, while the maximum hydration occurs earlier. As SZ proportion increases, the rate of heat release and the degree of hydration decrease. Measured hydration degrees differ significantly from the calculated values when SZ is added to Portland cement, especially later in the hydration process.