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This book provides an updated state-of-the-art review on new developments in alkali-activation.The main binder of concrete, Portland cement, represents almost 80% of the total CO2 emissions of concrete which are about 6 to 7% of the Planet's total CO2 emissions.

The aim of research was an influence evaluation of fly ash and zeolite on selected parameters of cement mortar. The scope of the research includes studies of composition and properties of fly ash itself from the thermal transformation of sewage sludge and natural zeolite (clinoptilolite). The research also included the determination of selected mechanical properties of designed mortars, both under normal conditions and after initial thermal loads. A mortar was designed based on CEM I 42.5 R Portland cement with different content of the applied additive in the amount of 5, 10 and 15% of the cement weight. In the course of experimental work, the bending strength of mortars heated at 20, 300, 500, 700 °C were tested. The resulting beam halves (40 × 40 × 160 mm) were used to test the compressive strength. The collected results made it possible to compare the properties of the mortars. The experiment confirmed the possibility of producing cement mortars modified with fly ash from thermal transformation of sewage sludge and zeolite from tuff deposits. The average compressive strength for the mortar containing 5% fly ash and zeolite was set at 28.7 and 27.1 MPa, respectively.

In this study, the water-repellent performance of Expanded Perlite (EP) coated with stearic acid (SA) at different coating/EP ratios (0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1%, 2%, 3%, 4% and 5%) and the capillary water absorption and thermal conductivity behaviors of the modified insulation mortars prepared at these different coating/EP ratios were investigated experimentally. In contrast to the existing literature, experimental studies were carried out for both coated and uncoated EP particles used in mortars to which water-repellent polymers were not added, and the minimum and maximum coating amounts showing the lowest capillary water absorption and slump were determined. In addition, the sustainability of modified insulation mortars consisting of EP-coated SA was determined by sustainable thermal performance (STP). In other words, this study is the first in the literature to determine how the thermal conductivity values of these mortars may change during their use in buildings. According to the experimental results, water absorption, which is an undesirable property, decreased significantly when coated with SA, and even SA-coated expanded coarse perlite (SCP) showed almost no water-absorption behavior at coating levels above 2%. The water-repellent performance of SCP was determined to be 83.2% between 0.1% and 0.4%. In addition, for coarse mortars (MCs), the best water-repellent performance was achieved at a 5% coating/EP ratio, with a 37% reduction in the capillary water-absorption coefficient. In addition, it was found that STP values increased as the coating/EP ratio increased. In other words, modified insulation mortars became more sustainable with an increasing SA coating/EP ratio. The highest STP values were observed in Groups 2 and 4 at a 5% coating/EP ratio, with MC-5 reaching 39.27% in Group 2 and MF-5 reaching 30.30% in Group 4. The results are important from a practical/industrial point of view and from a scientific point of view.

The work relates to a composition of an additive mortar with a volumetric weight below 250kg/mc, the thermal conductivity coefficient below 0,08kcal/m×h×°C, mechanical strengths more than 7daN/cm2 with self-cleaning effect after commissioning. In order to obtain a self-cleaning effect over time by eliminating chromatic deviations, the composition of ZnO, TiO2 and the three colored ceramics mixture is reformulated by optimizing the content based on color adjustment, by using a specialized software and CIE L·a·b· colorimetry for pressed bulk powders, at the medium one given by the patina. The composition optimization is performed by modifying, as appropriate, the addition rate of eggshell powder by a reformulated percentage related to the three fine colored ceramic powders. The freshly prepared mortar is applied to the restoration of the historical monument's facades through physical-structural and chromatic reintegration interventions. Depending on the conservation state of the apparent structures, two stages with differentiated specific operations are used: for surfaces without gaps, but chromatically degraded and with deposits of embedded dirt, it is spread with a trowel in the form of thin plasters on fiberglass mesh and in case of damage with deep lacunars areas the consolidation of the mobile structures will be first executed and grouting with a simple mortar based on river sand, expanded perlite, Portland cement and water in gravimetric ratio sand:perlite:cement:water = 2:i:2:5. After strengthen the same thin plasters will be applied on the fiberglass mesh. The new mortar allows the accomplishing of a series of advantages both in the processes of paste obtaining, as well as during commissioning and after, respectively within the period of integration in the tourist circuit.

The main goal of the research was to determine whether it was possible to reduce the cement content in mortar without compromising strength parameters. This is crucial for reducing the carbon footprint associated with cement production. In this article, the authors presented the results of research evaluating the effect of selected mineral additives on the strength properties of standard mortar after 7, 28, and 56 days of curing. The analysis of the effect of mineral additives was performed for CEM II and CEM III cements and seven selected mineral additives: white microsilica, Mikrosill+ microsilica, limestone powder, glass powder, glass granulate, and basalt powder. The study considered the use of mineral additives at 10% and 20% by weight of cement as a substitute. During the analysis of the test results, it was observed that the use of white microsilica and Mikrosill+ at 10% and 20% increased strength by approximately 50% compared to the reference samples. Importantly, strength was 50% higher with a 20% reduction in cement content. A positive effect of additives on strength parameters was observed only for CEMII cement. In the case of CEMIII cement, mineral additives reduce compressive strength.

In the article, the authors presented the results of research on the assessment of the effect of selected mineral additives on the strength properties of the standard mortar. The modification of the composition of the standard mortar made on the basis of CEM I 42.5R cement and quartz sand consisted of using seven selected mineral additives in the form of compacted microsilica, Mikrosill microsilica, limestone flour, glass flour, glass granulate, basalt flour, and fly ash in the amounts of 10 and 20% in relation to cement as its substitute. Reducing the share of cement in the standard mortar by 10% has a beneficial effect on improving the compressive strength by over 40% with the addition of microsilica, and in the case of bending strength, even by 10%.

There is no doubt that additive manufacturing (AM) with mortars presents an opportunity within the framework of a circular economy that should not be overlooked. The concepts of reduce, reuse, and recycle are fully aligned with this technology. One of the less explored possibilities is the utilisation of mining tailings as aggregates in printing mortars. This idea not only incorporates the concept of recycling but also contributes to a reduction in the production of potentially hazardous waste that would otherwise require storage in dams, thereby decreasing long-term environmental risks and improving the management of mineral resources. We employed a mortar composed of 12.5% material derived from mining tailings to highlight aspects of AM that are typically not subject to analysis, such as the necessity of considering contact interfaces between layers in structural design, the stackability of layers during the construction process, and the behaviour under fire and seismic events, which must be taken into account during the operational phase. Without aiming for exhaustiveness, we conducted a series of tests and computational modelling to show the significance of these factors, with the intention of drawing the attention of different stakeholders—including construction companies, regulatory authorities, standardisation agencies, insurers, and end-users.

Additive manufacturing (AM) technologies, including 3D mortar printing (3DMP), 3D concrete printing (3DCP), and Liquid Deposition Modeling (LDM), offer significant advantages in construction. They reduce project time, costs, and resource requirements while enabling free design possibilities and automating construction processes, thereby reducing workplace accidents. However, AM faces challenges in achieving superior mechanical performance compared to traditional methods due to poor interlayer bonding and material anisotropies. This study aims to enhance structural properties in AM constructions by embedding 3D-printed polymeric meshes in clay-based mortars. Clay-based materials are chosen for their environmental benefits. The study uses meshes with optimal geometry from the literature, printed with three widely used polymeric materials in 3D printing applications (PLA, ABS, and PETG). To reinforce the mechanical properties of the printed specimens, the meshes were strategically placed in the interlayer direction during the 3D printing process. The results show that the 3D-printed specimens with meshes have improved flexural strength, validating the successful integration of these reinforcements.

Carbonaceous mortars from Novae (Bulgaria) contain local loess, crushed bricks and ceramic dust (pozzolanic materials). The reaction between lime and pozzolanic additives occurs easily and affects the rate and course of leaching reaction of carbonates in orthophosphoric acid during the sample pretreatment for dating. The composition of the Bulgarian mortars does not allow for unambiguous conclusions about chronology, but together with the observations of experimental mortars, gives new guidelines in terms of pozzolanic mortar application for dating. The presented research illustrates the possible reasons of difficulties with obtaining the appropriate portion of gas for radiocarbon (14C) measurement. To verify the relative chronology of legionary baths complex in Novae, the charcoals samples were also dated in addition to the mortar.

This study investigated the technical feasibility and antimicrobial potential of incorporating ornamental rock, limestone, and ginger waste into coating mortars with the aim of developing an innovative and sustainable solution for civil construction. This study evaluated the synergistic action of these materials on the microbiological and mechanical resistance of mortar, contributing to the greater durability and efficiency of the coatings. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analyses were performed to characterize the morphology, chemical composition, and crystalline structure of the added materials, confirming their suitability for the cement matrix. Tests in the fresh state evaluated parameters such as density, consistency index, and entrained air content, demonstrating the viability of the formulations, whereas flexural and compressive strength tests indicated significant improvements in the mechanical performance of the modified mortar. Microbiological tests demonstrated a significant reduction in microbial colonization, indicating the action of ginger’s bioactive compounds, such as gingerol and shogaol, which have antimicrobial properties and are effective in inhibiting the growth of pathogenic microorganisms, as confirmed by the reduction in the bacterial colony count from 4 × 10[sup.2] to 1 × 10[sup.2] CFU mL[sup.−1] . Comparisons with conventional compositions indicate that the proposed approach outperformed traditional formulations in terms of both mechanical resistance and microbiological control. Thus, the results validate this research as a promising strategy for improving the durability and performance of coating mortars, reducing maintenance costs, and promoting the sustainable use of alternative materials in civil construction.