The main goal of this study was to compare two use cycles of natural aggregate concrete and recycled aggregate concrete, which is another way to compare the environmental impacts of recycled materials. A series of concrete mixtures with various replacement ratios of primary resources with recycled ones were prepared for this study. The mechanical properties of concrete mixtures were examined and were used for the design of structural elements in the same utilized properties. The two use cycles of a structural element were compared using life cycle assessment (LCA). In the first use cycle, the LCA of the structural element containing only primary raw materials was assessed. In the second use cycle, the LCA of a structural element in which primary materials were partially replaced by recycled ones was assessed. The obtained results confirm the potential use of high-quality recycled aggregate originating from local sources in some applications in building structures. Furthermore, the environmental assessment indicates the benefits of using recycled materials, such as environmental savings, especially the reduction of primary resource use, embodied energy, and embodied emissions, as well as reduction of the pressure on landfill sites.

The main aim of this paper is to carry out the environmentally based enhancement of a concrete mixture containing recycled materials whilst considering natural resource consumption as well as mechanical and thermal property levels. The developed concrete is intended to be used in mortarless masonry wall structures. Ten concrete mixtures with different types and replacement rates of recycled masonry aggregate and recycled expanded polystyrene were prepared, and their mechanical and thermal properties were experimentally investigated. It was found that the use of recycled masonry aggregate led to better thermal properties while maintaining sufficient mechanical properties. On the contrary, the addition of recycled expanded polystyrene did not significantly affect the thermal properties of concrete, but the mechanical properties considerably declined. For this reason, the recycled masonry aggregate is suitable to use as an aggregate for concrete masonry blocks for wall structures.

For a sustainable building industry, reusable construction with a low demand for primary resources is needed. Moreover, if we want to reduce the amount of construction and demolition waste, construction with recycled aggregate should be considered. To investigate the environmental impacts of such concrete construction, life cycle assessment (LCA) was used to compare the following types of concrete construction: Reusable blocks with recycled brick aggregate, reusable blocks with recycled concrete, reusable blocks with natural aggregate, and regular concrete wall. Firstly, the properties of new concrete with recycled aggregate were measured, such as physical, mechanical, and thermal properties. Then, different constructions were designed and assessed using the method of Institute of Environmental Sciences (CML2001) and the method of National Institute for Public Health and the Environment (ReCiPe 2016) as characterization methods. Unsurprisingly, the regular concrete wall had a higher impact on most of the impact categories, e.g., 113 kg CO₂ eq. (in the first scenario, using CML2001). In accordance with the circular principles, the reusability of blocks and recycling of aggregate are the main factors that affect the environmental impact of the constructions. Thus, the global warming potential (GWP) of construction with reusable recycled concrete blocks was only 53 kg CO₂ eq. (in the second scenario). Moreover, we show differences in the results of CML2001 and ReCiPe 2016, e.g., in the Photochemical Oxidant Creation category.

This paper deals with the possibility of using different types of waste glass powder in high-performance concrete (HPC) mixtures as a fine fraction replacement. Subsequently, both fractions are used in this research in concrete as a substitute for fine sand and silica flour. To use waste glass in a basic building material such as concrete, it is necessary to verify the basic chemical properties of the selected waste materials. Apart from the basic chemical properties, its environmental impact also appears to be an essential property of waste materials in general. Therefore, the research is mainly focused on the leaching and ecotoxicity experiments on high-performance concrete. HPC mixtures are designed based on the results of the analyzed chemical properties and previous research performed by our research team. Ecotoxicity of these concretes is then verified using Czech standards to evaluate. The results showed a positive impact on the ecotoxic properties of waste glass when used in concrete. A new ecotoxicity classification of waste materials and concrete mixes containing waste materials is proposed as a result of this research and summarized in the conclusion of this paper.

The utilization of recycled materials is one of the seven principles of sustainable construction. These principles based on the efficient use of resources were defined by the International Council of Building in 1994. Recycled materials such as recycled concrete aggregate or recycled brick aggregate from construction and demolition waste, waste glass from municipal waste or recycled waste gypsum from gypsum boards are able to use as replacement of primary raw materials in cement and concrete production. Concrete and cement production totally depends on the natural resources. The world production of concrete has been twelve times increased during last six decades. Nowadays, nearly one ton of concrete is produced each year for every human being in the world on average. On one hand, the use of recycled materials in cement and concrete production helps to reduce raw materials and urban land occupation. However, on the other hand, the recycled materials used as partial replacement of raw materials influence properties of final product. This paper reviews the different uses of recycled materials in cement and concrete production and the effect of the properties of these materials to the cement and concrete quality.

This investigation is focused on possibility of partial cement replacement in concrete mixture and its environmental assessment. The cement in concrete mixture is replaced by recycled cement powder from modified construction and demolition (C&D) waste. Recycled cement powder were prepared in laboratory from C&D waste of high quality road concrete. The main goal of this investigation is optimize amount of recycled cement powder used as partial replacement of cement in concrete mixture according to mechanical, deformation and physical properties of concrete and environmental impact. The properties of the fine-aggregate concrete with partial replacement of cement by recycled cement powder were tested for this verification. The life cycle analysis was calculated for this optimization. The properties and environmental assessment of the fine-aggregate concrete with partial replacement of fine aggregate by fine recycled aggregate were examined for comparison.