The aim of this paper is to investigate the environmental impact of the different aggregate extraction equipment used in the production of concrete. Different front-end loaders available on the market were compared. Using the LCA (Life Cycle Assessment) method, several environmental impacts including carbon footprint, ozone depletion and human toxicity per unit mass of concrete were analysed in SimaPro software. The average carbon footprint of the extraction process using the construction loader was estimated at 0.413 kg CO₂ eq per cubic metre of concrete, with the studied mix containing 1267 kg of gravel. The maximum observed difference in GWP values was 31.98%, while the average difference for most models was between 10% and 15%. The results show that using the right type of loader not only reduces costs, but also improves the final environmental profile of the concrete. By choosing the optimal loader equipment, CO2 savings in the concrete plant can reach the value of 5,200 kg CO₂ eq/year.

This article discusses the selective demolition of a family house in Ostrava Hošťálkovice carried out by the construction company Tomáš STRAUB s.r.o. This selective demolition of the building was carried out in order to map the economic impact of selective demolition and the subsequent recycling process of the waste obtained in normal construction practice. The aim of the article is to familiarize readers with the economic impact of selective demolition and its influence on the method of execution, including the economic motivation of the execution subjects. At the same time, the article also compares the economic impact in other regions of the Czech Republic based on the input data obtained.

The aim of this paper is to compare the environmental impacts of concrete samples in which traditional natural aggregates are replaced by recycled concrete. The concrete mixes with different proportions of aggregate replacement by recycled demolition waste, specifically railway concrete ballast, have been evaluated using the Life Cycle Assessment (LCA) approach. The study examines the water depletion per unit mass of concrete, comparing traditional concrete mixes with those containing recycled aggregates. The results show that the use of recycled aggregates can not only reduce material costs, but also improve the environmental profile of concrete by reducing water depletion by more than 70%. The water depletion decreases as the recycled aggregate content increases, with the biggest drop occurring between 75% and 100%. The research provides valuable information for the design and optimisation of concrete mixes to minimise the environmental impact of building materials in the context of sustainable construction.

This article deals with the possibility of using a recycled aggregate from railway ballast and platforms for the production of cement composites with a full or partial replacement of natural aggregates. This study evaluates the physical and mechanical properties of fresh and hardened concrete, as well as its resistance to water pressure, microstructure, and environmental safety. Four concrete recipes using an aggregate at the end of its life cycle from railway ballast (0/25 mm) and from the layers under the asphalt covering of the platforms (0/32 mm) were designed, with a 100% replacement for 0/25, 55% replacement (coarse fraction) for 0/32, and 45% sand for 0/4. The results have shown a significant influence of the type of aggregate on the strength, bulk density, and watertightness of the concrete. At 28 days, the compressive strengths of mixes R250, R400, R250N, and R400N were approximately 8, 20, 30, and 35 MPa, respectively, while after 90 days they increased to 10, 22, 37, and 45 MPa. The corresponding fresh concrete bulk densities ranged from about 1.95 to 2.27 g/cm³, and the water penetration depths ranged between 16 mm (best) and 27 mm (worst) among the mixes. Analyses of aqueous leachates have confirmed that the cement matrix effectively stabilizes the contaminants contained in the recycled aggregate and that the resulting products comply with the legislative limits. This study shows that an aggregate at the end of its life cycle from railway ballast and platforms can be effectively used to produce sustainable cement composites (concrete) with suitable mechanical properties and minimal environmental risks.

This article deals with the potential use of by-products from Třinecké železárny company—namely steelworks slag and spent foundry sand (SFS)—as an alternative to natural aggregate in the production of high-strength concrete. The aim of the study was to design and experimentally verify two concrete mixtures. For the first mixture (Mixture 1), natural aggregate was fully replaced by steelworks slag. For the second mixture (Mixture 2), the replacement was made by a combination of steelworks slag and SFS in the same volume ratio. The results have shown that Mixture 1 achieved a strength class of C70/85 and was classified as high-strength concrete. In contrast, Mixture 2, despite optimization of the composition, only achieved a strength class of C35/40, which does not allow for its classification as high-strength concrete.