Starting from the context of the principles of Sustainable Development and Circular Economy concepts, the paper presents a synthesis of research in the field of the development of materials of ...interest, such as cementitious composites or alkali-activated geopolymers. Based on the reviewed literature, the influence of compositional or technological factors on the physical-mechanical performance, self-healing capacity and biocidal capacity obtained was analyzed. The inclusion of TiO
nanoparticles in the matrix increase the performances of cementitious composites, producing a self-cleaning capacity and an anti-microbial biocidal mechanism. As an alternative, the self-cleaning capacity can be achieved through geopolymerization, which provides a similar biocidal mechanism. The results of the research carried out indicate the real and growing interest for the development of these materials but also the existence of some elements still controversial or insufficiently analyzed, therefore concluding the need for further research in these areas. The scientific contribution of this study consists of bringing together two apparently distinct research directions in order to identify convergent points, to create a favorable framework for the development of an area of research little addressed so far, namely, the development of innovative building materials by combining improved performance with the possibility of reducing environmental impact, awareness and implementation of the concept of a Circular Economy.
Starting from the context of the principles of Sustainable Development and Circular Economy concepts, the paper presents a synthesis of research in the field of the development of materials of ...interest, such as cementitious composites or alkali-activated geopolymers. Based on the reviewed literature, the influence of compositional or technological factors on the physical-mechanical performance, self-healing capacity and biocidal capacity obtained was analyzed. The inclusion of TiOsub.2 nanoparticles in the matrix increase the performances of cementitious composites, producing a self-cleaning capacity and an anti-microbial biocidal mechanism. As an alternative, the self-cleaning capacity can be achieved through geopolymerization, which provides a similar biocidal mechanism. The results of the research carried out indicate the real and growing interest for the development of these materials but also the existence of some elements still controversial or insufficiently analyzed, therefore concluding the need for further research in these areas. The scientific contribution of this study consists of bringing together two apparently distinct research directions in order to identify convergent points, to create a favorable framework for the development of an area of research little addressed so far, namely, the development of innovative building materials by combining improved performance with the possibility of reducing environmental impact, awareness and implementation of the concept of a Circular Economy.
Context. Innovative cementitious composites, in which the amount of cement is less or close to zero, use recycled aggregates, flz ash, slag, limestone slurry, which bring an input of calcium oxide, ...sodium and silicon dioxide, necessary for the formation of mineralogical compounds specific to the composite structure, with the role of improving mechanical performance and increasing their durability. In the literature, research results have been reported on increasing the durability of structures made of cementitious composite materials, by incorporating specific additions into their mass. Materials and methods. This study was selected and synthesized based on reports from the literature. Results and discussions. By using titanium dioxide nanoparticles in the mass of cementitious composites, according to the literature, an increase in their durability is achieved, from an aesthetic point of view. Thus, a certain amount of nanoparticles added to the mass of the compound contributes to the preservation and increase of the degree of white or color, without being influenced by the possibility of mass staining. The literature reports that cementitious composite materials, which has embedded in mass and titanium dioxide nanoparticles, shows increased mechanical and abrasion resistance, good behavior to the action of environmental factors, resistance to Frost-thaw and the action of chemical agents. By using slag in the composition of cementose materials and replacing an amount of cement with a maximum of 1% titanium dioxide, the fluidity of the base mixture does not change. Experimentally, the influence of nanoparticles on water absorption on the surface of these cement composites, which varies in close connection with the amount of nanoparticles introduced into their composition, has also been shown. Conclusions. The use of titanium dioxide nanoparticles in the cementitious composite mass provides the structural components durability, by increasing the degree of hydrophilicity, resistance to fouling and self-cleaning ability under the catalysis of UV rays, resistance to the action of microorganisms and degradation under the action of climatic factors. Also on the basis of the experimental results it is considered that it is necessary, on a case-by-case basis, the optimal quantitative analysis of nanoparticles used as an addition in the cement matrix by which the quality of the self-cleaning process is optimized, depending on the use, climate, degree and duration of sunlight. Acknowledgment. This paper was financially supported by the Project "Entrepreneurial competences and excellence research in doctoral and postdoctoral programs - ANTREDOC", project co-funded by the European Social Fund financing agreement no. 56437/24.07.2019.
Worldwide, it is now known that industrial by-products rich in silicon (Si) and aluminum (Al) can be transformed by alkaline activation into so-called “green concrete”, an efficient and sustainable ...material in the field of construction; the geopolymer material. In this work, geopolymer materials produced using fly ash and marble dust or blast furnace slag were studied to assess the influence of these substitutions on the performances of the final product. Geopolymer materials have been characterized by physico-mechanical methods, FTIR spectroscopy and microscopically. The analysis of the results indicates the reduction of the mechanical strength performance by substituting the fly ash as the raw material.
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