Since the early seventies with the work of Akira Fujishima on photocatalytic and superhydrophilic properties of titanium dioxide (TiO₂), also known as the Honda–Fujishima effect, photocatalysis has been investigated and progressively implemented in cement-based materials towards the development of self-cleaning, air-purifying and antiseptic materials, buildings and infrastructure. Although important achievements have been obtained at the laboratory scale, their real scale application has had some limitations mainly due to the low efficiencies obtained during adverse environmental conditions. Therefore, this article presents the challenges and opportunities of using of titanium dioxide in cement-based materials towards the development of truly efficient sustainable building materials. First, TiO₂ photocatalysis and its incorporation in cementitious materials are presented. Second, self-cleaning, air-purifying and antimicrobial properties are discussed in terms of the lab and pilot project results. Third, conclusions regarding the different multifunctional properties are given towards the real application of TiO₂ photocatalysis. Particularly, complementary technologies and strategies are presented in order to increase the above-mentioned multifunctional properties.

The construction industry faces increasing pressure to reduce its environmental impact while meeting the growing demand for infrastructure. One approach to achieving this goal is the use of industrial waste as a replacement for traditional supplementary cementitious materials (SCMs). This study investigates sugarcane bagasse ash (SCBA), addressing the future scarcity and increased cost of other commonly used SCMs. Despite existing literature, the use of SCBA is hindered by several unknowns. This research evaluates SCBA’s performance in mortars, focusing on the effects of curing temperature and particle size variation. Mortar samples were prepared with SCBA replacements from 0% to 30% by mass of cement and cured at 21 °C and 45 °C for 7, 28, and 90 days. The results suggest potential for SCBA replacement up to 30%, emphasizing its sustainability and economic benefits. A cost analysis was also conducted, demonstrating the economic viability of SCBA as an alternative to traditional cement for practical applications.

In light of globalization and escalating environmental concerns, society is increasingly confronted with the challenge of implementing the concept of a circular economy, which promotes the recycle of waste materials and offers a promising solution. Aluminum dross, a byproduct of the aluminum production process, poses environmental issues when not properly managed. Therefore, this study examined the technical and financial feasibility of implementing an industrial process for the recovery and transformation of aluminum dross into raw materials for use in cementitious materials. From a technical perspective, two processes were evaluated: washing and the grindability of the material. An X-ray diffraction analysis allowed to verify an approximately 88% reduction in AlN (a compound that produces ammonia gases when reacting with water) after washing the material. The most efficient grinding process was achieved using an impact mill. The financial feasibility study was carried out through cash flow forecasting, which revealed that a minimum selling price of USD 0.12 per kilogram of processed material could generate a return rate of 9.7% over a five-year period. These results present opportunities for the metal and construction industries to develop products with low CO₂ emissions by reintegrating aluminum dross into a productive cycle. Moreover, this work serves as a valuable reference for policymakers and environmental authorities seeking to formulate new legislation or incentives that encourage companies to invest in environmentally focused projects.

This paper presents an innovative approach to road assessment, focusing on enhancing the Pavement Condition Index (PCI) and Visión Inspection de Zones et Itinéraires Á Risque (VIZIR) methodologies by integrating Unmanned Aircraft System (UAS) technology. The research was conducted in an urban setting, utilizing a UAS to capture high-resolution imagery, which was subsequently processed to generate detailed orthomosaics of road surfaces. This study critically analyzed the discrepancies between traditional field measurements and UAS-derived data in pavement condition assessment. The study findings demonstrate that photogrammetry-derived data from UAS offer at least similar or, in some cases, improved information on the collection of a comprehensive state of roadways, particularly in local and collector roads. Furthermore, this study proposed key modifications to the existing methodologies, including dividing the road network into segments for more precise and relevant data collection. These enhancements aim to address the limitations of current practices in capturing the diverse and dynamic conditions of urban infrastructure. Integrating UAS technology improves the measurement of pavement condition assessments and offers a more efficient, cost-effective, and scalable approach to urban infrastructure management. The implications of this study are significant for urban planners and policymakers, providing a robust framework for future infrastructure assessment and maintenance strategies.

This paper presents a study of the effect of a superabsorbent polymer (SAP) for autogenous shrinkage control on the uniaxial tensile behavior of steel fiber reinforced concrete (SFRC). The use of fibers and SAP potentially increases the durability of the concrete, preventing cracking by autogenous shrinkage and enhancing post-cracking behavior. Furthermore, SAP can provide further hydration for self-healing purposes and improve the ductility of the SFRC. In order to evaluate the effect of the addition of SAP in SFRC, dog-bone SFRC specimens with different dosages of superabsorbent polymers were cast and tested under uniaxial tension. The digital image correlation (DIC) technique was used to understand the effect of SAP on the steel fibers’ crack-bridging mechanisms. Surface strains and crack openings were inferred using the DIC technique. The effect of SAP and fibers on fresh and hardened concrete was individually investigated by flow tests and compressive strength tests. Autogenous shrinkage was measured in plain concrete to investigate the minimum SAP content required to mitigate autogenous shrinkage of 0.3%. The use of 0.3% SAP was also sufficient to reach multiple cracking behavior. This content of SAP completely suppressed the autogenous shrinkage with minimal side effects on compressive strength. An analytical formulation for the tensile behavior of SFRC was developed using the variable engagement model, presenting a mean correlation of R² of 0.97 with the experimental results.

The following paper proposes an Unmanned Aircraft System (drone) inspection framework for communities where guidelines for this emerging technology have yet to be provided. The framework involves pilot training in an area with similar features to the structure to be inspected, developing best inspection practices for future application, selecting a bridge for detailed inspection using non-destructive testing methods such as visual inspection, and inspecting the bridge using the UAS inspection framework developed for the area. The results of both reviews are compared, and the framework is validated. The final inspection framework is presented in the paper, along with relevant conclusions and future work. The proposed framework can be valuable for infrastructure owners and inspectors to conduct more efficient and cost-effective bridge inspections while ensuring safety in communities with limited UAS guidelines and research work. The structural analysis, qualitative assessment, and load rating of the case study are presented as proof of concept on the effectiveness of the UAS bridge inspection and its advantages.