Élida Margalho

Self-cleaning cementitious materials, particularly with TiO₂-based photocatalytic coatings, offer significant benefits by reducing surface deterioration and maintenance requirements, even in harsh urban environments. Despite the growing interest in self-cleaning cementitious materials, an international standard test method to calculate their efficiency has not yet been established for this specific type of substrate. The objective of this study was to evaluate and compare three different techniques for assessing the photocatalytic efficiency (PE) of cementitious materials coated with TiO₂: (i) spectrophotometric colorimetry (SPC); (ii) digital image processing-based colorimetry (DIP); and (iii) UV-Vis spectrophotometry (UV-Vis). Rhodamine B (RhB) was used as a model pollutant, and the photocatalytic efficiency was monitored under UV-Vis light. The results showed that each method has distinct advantages and specific challenges. SPC proved to be a practical and efficient approach, similarly to DIP, which was also accessible, providing reliable and accurate measurements. UV-Vis stood out for its precision but required careful application on cement-based substrates due to their unique porosity and adsorption characteristics. These results underscore the complementary potential of these techniques and highlight the importance of developing standardized protocols that integrate their strengths to facilitate the wider adoption of self-cleaning materials.

Building façades are constantly exposed to atmospheric pollution and various external agents that can degrade their aesthetic qualities and introduce degradation patterns that affect the durability and performance of the materials. Façades with self-cleaning properties are important in the modern construction industry and the conservation of historic buildings, as they reduce costs and allow the preservation of original surfaces without the need for invasive interventions that could compromise cultural heritage. This study does a comparative analysis of the application of photocatalytic coatings composed of aqueous dispersions of titanium dioxide nanoparticles (TiO₂) and zinc oxide microparticles (ZnO) on cementitious substrates for use on façades by two functionalisation methods: spray coating and dip coating. A comprehensive characterisation was carried out using techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS) to assess the morphology, crystal structure and light absorption properties of the photocatalyst particles while Energy Dispersive Spectroscopy (EDS) and scanning electron microscopy (SEM) were employed to evaluate the substrate. The self-cleaning performance was evaluated by monitoring the degradation of Rhodamine B (RhB) dye under simulated sunlight. Spectrophotometric analysis was used to assess the colour coordinates using a standard colour system (CIELAB colour space). The results showed that the photocatalytic coatings improved the surfaces' self-cleaning properties while maintaining the substrate's original aesthetics. Spray-applied micro-ZnO-based coatings showed the most significant effectiveness in terms of self-cleaning.

This study investigates the effect of iron-modified nano-TiO₂, using the co-precipitation method with different concentrations of FeCl₃ (0.1, 1, and 10%), to improve its photocatalytic properties for outdoor applications. To this end, modified and unmodified nano-TiO₂ were characterized using different techniques. The optical properties were characterized by diffuse reflectance spectroscopy (DRS) followed by band gap calculation. X-ray diffraction (XRD) was used to analyze the crystalline structure. Chemical and morphological characterization were carried out using energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The photocatalytic activity was investigated by decolorizing Rhodamine B aqueous solutions under similar sunlight irradiation. The results indicate that the modification improved light absorption in the UV range for all iron concentrations; however, only the concentration of TiO₂: FeCl₃ (10%) shifted the absorption to the visible region. Also, including Fe³⁺ in TiO₂ decreased the band gap energy from 3.14 to up to 2.80 eV. There were variations in crystallite size from 21.13 to up to 40.07 nm. The nano-TiO₂ morphology analysis showed that it did not change after iron modification. EDS showed an FeCl₃ peak only at higher concentrations (10%). In addition, the 0.1% Fe-modified TiO₂ exhibited the highest activity in the photocatalytic process, with an efficiency of 95.23% after 3 h of irradiation.

A smart asphalt mixture holds new capabilities different from the original ones or can react to a stimulus. These capabilities can be categorized based on smartness or function: smartness, mechanical, electrical, optical, energy harvesting, electromagnetic wave/radiation shielding/absorbing, and water related. The most important capabilities applied to asphalt mixtures are the photocatalytic, self-cleaning, self-healing, superhydrophobic, thermochromic, deicing/anti-icing, and latent heat thermal energy storage abilities. This research deals with a bibliometric review of the peer-reviewed journal articles published on the Scopus database, with the strings of terms related to these capabilities and asphalt or bitum in their titles, abstracts, and keywords. The review analysis highlighted the increasing number of accumulated publications, confirming the relevance of this research topic in recent years. The capability most often referred to was self-healing. The study showed that China was the most productive country. Research articles were mostly published in the journal Construction and Building Materials. Several techniques and methods are being developed regarding smart asphalt mixtures; for that reason, this research work aims to evaluate the literature under a bibliometric analysis.

This research reports a simple, innovative, and low-cost doping method of TiO₂ nanoparticles presenting the effects of calcination and the weight ratio of TiO₂:FeCl₃ (1:0.33–1:4.5). The photocatalytic activity of the nanomaterials was investigated by decolorizing Rhodamine B (RhB) dye in an aqueous solution. The main results showed that there is anatase-to-rutile transformation after the calcination process. The Fe-doped process modified the TiO₂ spectrum and showed a connection in the Ti–O–Fe vibration. The particle size is within the nanometer range, between 20–51 nm, except for calcined TiO₂. The inclusion of Fe in TiO₂ decreased the band gap energy from 3.16 (reference) up to 2.06 eV (1:3). Additionally, after the calcination, there was a decrease in this value from 3.03 eV (reference) up to 1.95 eV (1:1.6). The TiO₂, with a ratio of (1:1.6), showed the highest activity in the photocatalytic degradation of RhB with an efficiency of 93.8% after 3 h of irradiation.

Asphalt road pavements are usually dark and, consequently, have a low albedo. Therefore, they absorb energy as heat, increasing the Urban Heat Island (UHI) effect, which impacts the environment, energy consumption, and human health. Through the functionalization with thermochromic materials (TM), this work aims to develop a smart asphalt pavement able to change its surface color, increasing the reflectance, and thus mitigate this phenomenon. To achieve this goal, asphalt substrates were functionalized by a surface spray coating of a thermochromic solution (TS) containing aqueous solution of thermochromic microcapsules (thermocapsules), dye, and epoxy resin. To evaluate the functionalization features, Fourier Transform Infrared Spectroscopy (FTIR), and Thermal Differential test (TDT) with cyclic temperature variation were performed in the functionalized asphalt binder. Moreover, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectrometry (EDS), a Quick Ultraviolet Accelerated Weathering Test (QUV) with Colorimetry test, and an adaptation of the Accelerated Polishing Test (APT) were performed on the functionalized asphalt mixture. The results indicate that the functionalization of asphalt substrates with TS exhibits a reversible color-change ability, higher luminosity values when subjected to temperatures above 30 °C, and wear resistance.

Assessment rubrics are recognized for their positive effects, being defined as an evaluative instrument that establishes assessment criteria and performance levels. In this sense, assessment rubrics can be associated with professional practices for more authentic assessment processes. In the context of Project Management, the International Project Management Association (IPMA) has developed a framework that establishes the individual competences for professionals working in the area, the Individual Competence Baseline (ICB). The objective of this study is to propose a process of rubric development for competence assessment in Project Management. A rubric for Leadership competence was developed to show the applicability and relevance of the proposed process. The research methodology adopted in the study was Design Science Research. The application and evaluation of this rubric in a pilot study show that the rubric development process allowed the creation of a specific rubric for the assessment of leadership competence. This paper guides those who need to develop and assess project management competences, and it is intended to propose a replicable process for the other ICB competences.