http://repositorio.ufc.br/handle/riufc/81525 Sun, 31 May 2026 08:30:12 GMT 2026-05-31T08:30:12Z http://repositorio.ufc.br/handle/riufc/86484 Título: Avaliação de um compósito cimentício piezoresistivo com resíduos siderúrgicos Autor(es): Barros, Emmily Ediviges Ferreira Abstract: Structural Health Monitoring (SHM) has become an essential tool for preventing failures in civil structures, particularly in light of recent structural collapses that highlight the need for more efficient and continuous performance monitoring solutions. In this context, self-sensing cementitious composites based on the piezoresistive effect have emerged as a promising alternative to conventional monitoring systems, which present limitations related to durability, cost, and integration with cement-based materials. However, most of these solutions still rely on carbon-based conductive materials, whose application is limited by high cost and the complexity of dispersion within the cementitious matrix. In this regard, this study evaluates the potential of steelmaking by-products—Basic Oxygen Furnace (BOF) slag and Kambara Reactor (KR) desulfurization powder—as conductive aggregates in self-sensing cementitious composites. The materials were obtained from a steel plant located at the Pecém Port Industrial Complex (CE, Brazil) and subjected to processing procedures, including particle size adjustment and volumetric stabilization through accelerated weathering for BOF slag. Three mortar mixtures were produced: a reference mixture and two others with total replacement of conventional fine aggregate by steelmaking residues, using a 1:3 mix proportion and a waterto- cement ratio of 0.55. The mortars were characterized in terms of physical, mechanical, and microstructural properties through water absorption, void index, compressive strength, ultrasonic pulse velocity, and scanning electron microscopy. The electrical and piezoresistive behavior was evaluated using the four-probe method, with current monitoring in specimens subjected to cyclic loading. The results showed that the incorporation of steelmaking residues significantly influenced the electrical behavior of the composites. The mixture containing KR slag exhibited the lowest electrical resistivity and the highest piezoresistive sensitivity, demonstrating a strong ability to respond to applied loading, although it presented lower mechanical performance. In contrast, the BOF slag mixture showed a more balanced behavior, combining satisfactory mechanical performance with a consistent electrical response, indicating its potential for application in integrated structural sensing systems. Therefore, the findings demonstrate that steelmaking residues can act as active functional phases in selfsensing cementitious composites, contributing not only to the development of smart materials but also to the valorization of industrial by-products. Their incorporation promotes the reduction of conventional material consumption, supports circular economy strategies, and expands the applicability of cementitious composites in structural health monitoring. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/86484 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/86219 Título: Avaliação dos impactos das mudanças climáticas na degradação do patrimônio histórico Autor(es): Magalhães, Allan Fernandes Abstract: The adaptability of buildings, whether new or existing, to climate change is a central topic in current research. Phenomena such as temperature and humidity variations can significantly influence the thermal and mechanical behavior of constructions, accelerating the deterioration of building materials and compromising structural integrity. This effect is intensified in historical buildings, which are more susceptible due to the characteristics of their materials. The objective of this study is to propose an innovative, integrated, and multiparametric methodology to assess the degradation of building materials in historical sites and their evolution, correlating the effects of climate change with the potential worsening of structural damage. The proposed approach includes on-site inspections, damage assessment, development, calibration, and validation of numerical models to predict thermal and structural responses, identifying the most vulnerable areas. Additionally, characterizing urban microclimates is essential to understanding how specific environmental factors influence the degradation of historical buildings. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/86219 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85434 Título: Avaliação das propriedades eletromecânicas de compósitos cimentícios à base de MWCNTs, CFs e EPS para aplicação em sensoriamento Autor(es): Araújo, Antônio José Cruz de Abstract: Concrete structures are widely used due to their durability, but they are subject to degradation, which compromises their integrity. In this context, self-sensing cementitious composites, obtained through the incorporation of electrically conductive additions such as carbon fibers (CFs) and carbon nanotubes (CNTs), emerge as an alternative for structural monitoring due to their piezoresistive properties. In light of this, the present study aimed to develop lightweight self-sensing cementitious composites based on multi-walled carbon nanotubes (MWCNTs), CFs, and expanded polystyrene (EPS) for sensing applications. To evaluate the behavior of the produced mortars, tests were carried out for workability, water absorption, void index, and density, ultrasonic pulse velocity, compressive strength, and electromechanical performance. Initially, a pilot study was conducted to investigate the isolated effects of different concentrations of CFs (0.10%, 0.20%, 0.50%, and 1.00%) and EPS (20% and 30%), in addition to the incorporation of 0.2% MWCNTs. Mortars produced with MWCNTs showed good electromechanical results but exhibited an 8.95% reduction in compressive strength, indicating agglomeration. Among the mortars with CFs, the 0.1% content showed the best results, with a compressive strength of 55.58 MPa and a favorable electromechanical response. For EPS, the 30% content caused a significant reduction in compressive strength of 51.30%, while the other parameters remained close to those observed for the 20% content. Based on the mixtures that presented the best compressive strength and piezoresistive behavior in the pilot study, the optimal contents for multicomponent composites were defined (20% EPS, 0.1% CFs, and 0.2% MWCNTs), leading to the production of combinations such as EPS + MWCNTs, EPS + CFs, and EPS + MWCNTs + CFs. Among the multicomponent mortars, the EPS + CFs combination showed the best performance, with the most standardized electromechanical response, a compressive strength of 37.68 MPa, and lower electrical resistivity compared to mortars with a single addition. In general, with the replacement of fine aggregate by EPS, no significant variations in resistivity were observed in response to cyclic loading, indicating that the greater deformations typical of EPS-based composites, although they may promote closer contact between carbonaceous additions, do not necessarily increase the sensitivity of the resulting composite. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85434 2026-01-01T00:00:00Z http://repositorio.ufc.br/handle/riufc/85426 Título: Gestão da manutenção e mitigação de riscos em sistemas de proteção contra incêndio em edificações históricas por meio de BIM/FM e estruturação sistêmica da informação Autor(es): Bessa, Maycon Handerson de Oliveira Abstract: This dissertation proposes and validates an integrated methodology based on Historic Building Information Modeling (HBIM) and Facility Management (FM) to support maintenance management and risk mitigation of fire protection systems in historic buildings. The approach is oriented toward systemic information structuring, automation of maintenance processes, and decision support in operational and emergency contexts, considering the technical, constructive, and heritage-related constraints inherent to this type of built asset. The methodology was applied through a case study conducted at the José de Alencar Theatre, comprising on-site technical assessment, definition of operation and maintenance-oriented information requirements, development of a system-oriented and simplified HBIM model, semantic enrichment of building elements, structuring of maintenance plans, and automated integration of maintenance data within the modeling environment. In addition, an asset information structure centered on systems and operational loops was developed and integrated with a relational database and a visualization environment, enabling the analysis of functional interdependencies and the simulation of failure scenarios in fire detection and suppression systems. The results demonstrate the feasibility of a lean digital model, achieving a significant reduction in model complexity and data volume without compromising the information requirements necessary for operation and maintenance. The organization of assets according to functional taxonomy and operational loops enabled the identification of impact zones and enhanced response capability in critical situations. The main contributions include the development of the F2SM framework, the adoption of a maintenance-oriented strategy for decoupling geometry and information, and the proposal of systemic information structuring as a foundation for maintenance management and risk mitigation in historic buildings. Tipo: Dissertação Thu, 01 Jan 2026 00:00:00 GMT http://repositorio.ufc.br/handle/riufc/85426 2026-01-01T00:00:00Z