The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

Current insulation materials applied in construction engineering and the building industry are generally petrochemical-based polymers and recycled thermal insulation materials. The environmental effects of these materials’ production processes are substantial, despite their high thermal insulation performance. Consequently, the researchers conclude that it is essential to develop and produce insulating materials with superior thermal properties, minimal environmental impact, and a reasonable cost. The study concentrated on the application of insulation materials derived from biomass in the development of thermal insulation. The purpose of this review is to investigate and develop the possibilities of using biomass wastes as renewable and eco-friendly thermal insulation materials for construction engineering and the building industry. The thermal conductivity of those materials was measured using the hot plate and hot box methods, two of the most widely used hot processing methods. With a relatively low thermal conductivity (< 0.100 W·m⁻¹·K⁻¹), this review provides critical scientific insight into potential building insulation materials derived from biodegradable and abundant resources. It was observed that these materials are appealing for use in building and construction because they have a number of potential advantages from technical, economic, environmental, and green credentials perspectives. The collection of information enables some conclusions regarding the different biomass waste–derived insulation materials that have already been investigated and identifies gaps in the literature. Finally, the scope of commercialization pathways and future research directions to validate the proposed material alternatives’ claim for commercial-scale applications has been identified in this review. Graphical Abstract

The aim of the study was to generate rules for the prediction of the chloride resistance of concrete modified with high calcium fly ash using machine learning methods. The rapid chloride permeability test, according to the Nordtest Method Build 492, was used for determining the chloride ions’ penetration in concrete containing high calcium fly ash (HCFA) for partial replacement of Portland cement. The results of the performed tests were used as the training set to generate rules describing the relation between material composition and the chloride resistance. Multiple methods for rule generation were applied and compared. The rules generated by algorithm J48 from the Weka workbench provided the means for adequate classification of plain concretes and concretes modified with high calcium fly ash as materials of good, acceptable or unacceptable resistance to chloride penetration.