This paper describes the production and performance characteristics of lightweight concrete (LWC) made from porous aggregates, such as expanded glass (EG), made from glass waste, and crushed expanded polystyrene waste (CEPW), obtained by crushing packaging waste from household appliances and ordinary Portland cement (OPC). During the study, the LWC density, thermal conductivity, compressive strength, bending strength, water absorption, deformations, composite structure, and freeze–thaw resistance were evaluated. By changing the amount of OPC and replacing part of the EG with CEPW, it was possible to reduce the thermal conductivity from 0.0977 to 0.0720 W/(mK). The presence of CEPW did not degrade compressive and bending strength or long-term water absorption of LWC. The influence of the amount of porous aggregates and OPC on the resistance to freezing and thawing was investigated by two methods. In one case, the freezing resistance was studied by the method of one-sided freezing of LWC structural indicators and, in the other case, the freezing resistance was determined by the decrease in compressive strength after 25, 100, and 200 freeze–thaw cycles. By modifying the structure with CEPW aggregate the durability of LWC products was increased and deformations were decreased.

This study is devoted to assessing the hygroscopic and durability properties of a clay composite with the addition of a natural polymer. Modified polymer-retrograded starch hydrogel (RSH) of various concentrations (2.5, 5.0, 7.5, and 10.0%) and heating times (3 and 5 h) were used as clay stabilizers. The introduction of retrograded starch tends to increase the drying rate of clay composites at the early period of 0–4 days without the formation of shrinkage defects. Moisture uptake increased by 29% (from 140 to 180 g/m²) over the control clay composite without RSH. The hysteresis rate of the clay samples modified with RSH decreased by half (from 0.3 to 0.15%), but the hygroscopic properties were better. The use of RSH polymer increased the durability (water erosion resistance) of the clay composite. The obtained composite has great potential for indoor use due to its high moisture-regulating and durability properties.

This study deals with the effect of MSWI (municipal solid waste incinerator) fly ash on fired clay bricks. Initially, the MSWI fly ash was characterized by its chemical composition and morphology. Different ratios of the MSWI fly ash (0, 2.5, 5.0 and 7.5 % by mass) were added to the clay brick. Clay brick samples were heated on 1000 °C temperatures for 1 h. The clay brick properties of the resultant material then determined, including shrinkage (after drying, after firing), density, water absorption, effective porosity and total open porosity and compressive strength. Toxicity Characteristic Leaching Procedure tests were also conducted. The results indicate that the heavy metal, chloride and sulphate concentrations in the leachates met the current regulatory thresholds (Waste Directive 2003/33/EC). Increasing the amount of MSWI fly ash resulted in an increase in the water absorption and a decrease in the compressive strength of the MSWI fly ash clay bricks. The addition of MSWI fly ash to the mixture reduced the degree of firing shrinkage. The effects of MSWI fly ash addition on the durability (frost resistance) of the clay bricks were investigated. This indicates that MSWI fly ash is indeed suitable for the partial replacement of the clay in the bricks.

This study is dedicated to the development of an environmentally friendly building material made from non-fired clay, stabilized with various biopolymers (starch, alginate, and chitosan)

This study investigates the potential use of sewage sludge (SS) and sewage sludge ash obtained from the combustion of sewage sludge–wood-chip briquettes (BSSA) as additives in fired clay bricks. The novelty of this study lies in comparing these two waste-derived additives within the same clay matrix. Clay mixtures containing 5–20 wt.% SS or BSSA were prepared and fired at 1000 °C. The raw materials and fired products were characterized using chemical and thermal analyses, X-ray diffraction (XRD), and scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS). Compared with the control specimens, SS incorporation reduced bulk density by 10–35% and compressive strength by 32.5–62.8%, while BSSA reduced these properties by 8–18% and 29.6–58.8%, respectively. Water absorption increased with both additives. Microstructural observations indicated increased pore formation, particularly in SS-containing specimens, consistent with the burnout of organic constituents during firing. The results suggest that incorporation levels of 5–10 wt.% offer a more favorable balance of properties than 20 wt.%. The use of BSSA may support cascade waste utilization by combining energy recovery with subsequent ash reuse.