Computational mechanics, particularly the Finite Element Method, has become an essential tool for engineers to simulate the behavior of structures under various conditions. Additionally, hyperelastic models are commonly used to represent the behavior of highly deformable materials, such as elastomers and polymers, which are increasingly utilized in engineering applications. The use of hyperelastic models is suitable for capturing nonlinear stress-strain relationships of materials, but the accuracy of these models may vary depending on material properties and deformation regimes. Therefore, it is important to select an appropriate model for specific conditions of interest. In this context, hyperelastic models including Mooney-Rivlin, Neo-Hookean, Ogden, and Yeoh were implemented in a computational code in FORTRAN using the Finite Element Positional Method along with Reissner's kinematics and the Newton-Raphson method for nonlinear analysis of plane frames with samples of elastomers containing varying percentages of carbon black. Subsequently, the Method of Least Squares was employed to determine the constitutive coefficients of hyperelastic models. The performance of each model was then evaluated by comparing the force vs. displacement curve of the material under study. Ultimately, it was concluded that the Yeoh and Ogden models exhibited consistent values, while the Neo-Hookean and Mooney-Rivlin models deviated. This observation was attributed to the number of constants in the formulation of these models. Furthermore, it can be stated that the use of the positional finite element method for nonlinear analysis of plane frames with hyperelastic models performs well, especially after the modifications proposed in this work to the formulations of hyperelastic models. These modifications consisted of adding the first invariant of deformation from the simple shear formulation to include the consideration of distortion in the specific energy of deformation of hyperelastic models.

In an increasingly evident and fundamental way is the search for the conservation of cultural heritage, as a way of maintaining and preserving the identity of a society. Historic buildings are an integral part of this heritage and the best way to conserve and safeguard them is to analyze and understand the materials and methods used during the period of their construction, in order to carry out a more harmonious and efficient restoration, with materials similar to the originals. In this context, this work aims to characterize and study the mortar covering the ruins of the Church of Santa Rita de Cássia, in the city of Pedro Velho/RN - Brazil. To this end, on-site visits were carried out for visual observations and photographic records of the historic building, collecting a total of 30 (thirty) samples of coating mortar for subsequent physical-chemical characterization through visual, tactile analysis and analytical techniques carried out in the laboratory, FRX, DRX, mortar content (binder:aggregate) tests by acid attack and granulometric analysis were developed. From these analyzes it was found that the mortars analyzed are rich in lime, with a binder of a calcitic nature and sand of siliceous origin, as aggregate, with the presence of clay in their composition, presenting different binder:aggregate ratios in almost all cases. mortars, ranging from 1:3 to 1:13, proving their production without any technological control. Therefore, for possible future restoration, it must be done with mortar made of lime and sand with different traits.

This research aimed to analyze the behavior of a reinforced concrete two pile caps with embedded socket and shear keys in the presence of additional reinforcement. A numerical model was developed in the ABAQUS software, based on the finite element method. The numerical models were calibrated and validated based on experimental tests by Barros (2013).
A parametric analysis of the models was carried out in two stages, which also included the variation in the compressive strength of the concrete of the pile caps. The first step consisted of varying the steel area and arrangements of the additional reinforcement proposed by Barros (2013). The second stage included the variation in angle and configuration of the additional reinforcement. It was observed throughout the parametric analyzes that the compressive strength of the pile caps was the parameter that most influenced the load capacity of the models by providing greater resistance to the compression struts, since the models' collapse occurred due to the crushing of the concrete in the struts in the connection region. The results of the first stage showed that the additional reinforcement, originally proposed by Barros (2013), does not influence the load capacity of the pile caps and crack control. The analyzes of the second stage showed that the new proposed configurations A1, A2 and A1+A2 enabled better control of the cracking of the pile caps. Reinforcement A1 acted to control diagonal cracking of the pile caps strut, resulting in an increase in load capacity between 0.94% and 2.55%, varying according to the pile caps’ compressive strength. The A2 model was more efficient, controlling central cracking and diagonal cracking of the pile caps struts, resulting in an increase in load capacity between 5.31% and 10.19%. The A1+A2 model presented practically a superposition of effects, controlling both diagonal cracking and central cracking. It was the arrangement that provided the greatest increases in load capacity, which varied between 6.77% and 12.48%. Thus, the importance of reinforcement for controlling cracking in pile caps with embedded socket with shear keys is demonstrated. Since, in addition to resulting in better behavior in service and greater durability of the structural element, they can also act by delaying the collapse mechanisms of the pile caps and, thus, increasing their load capacity, as was observed more significantly on models A2 and A1+A2.

3D printing has generated changes in traditional processes, ensuring greater freedom of design with complex geometries and the possibility of using various materials. However, the cementitious mixtures 3D printing on concrete (3DCP) have high Portland cement contents to meet the printing parameters, so, in order to satisfy the more sustainable construction aspect, an alternative is to partially replace cement by supplementary cementitious materials (SCMs). As also, in view of the similarity of the 3D printing system with that of structural masonry, a comparative evaluation between the aforementioned methods is of importance. Based on this, the present study aims to develop 3DCP blocks, prisms and mini-walls with limestone filler and metakaolin in partial replacement of Portland cement, aiming to evaluate the mechanical behavior of these 3DCP elements in comparison to the structural masonry system; in addition to analyzing their performance in the fresh and hardened state. The results show that the lime filler increases the fluidity and the open time of the mixture, while the metakaolin increases the viscosity of the mixture. It was also found that the geometry of the 3DCP containing an internal lattice ensured greater stability to the material, being favorable to the buildability of the 3DCP. As well as, it was possible to prove the similarity of the mechanical behavior of the structural masonry system with 3DCP, with respect to the brittle failure mode and the compressive strength.

Road transport in Brazil is the main means of movement of goods, services and people nowadays. Given this situation, with population growth, it is necessary to carry out maintenance and construction of highways in the country, which leads to the exploitation of natural resources and the generation of waste that cause major environmental problems. In this segment, it's important mentioning that in the production process of Hot-Machined Asphaltic Concrete (HMAC) a residue called Brita Graduate with Asphalt (BGA) is generated, a noble material, composed of coarse aggregates, small aggregates and Petroleum Asphalt Cement (PAC). Thus, the present study analyzed the technical feasibility of using BGA in proportions of 0%, 2%, 4%, 6% and 8%, by mass, in relation to new hot-machined asphalt mixtures for application in of road works. For this, chemical characterization analysis by X-Ray Fluorescence (XRF), mineralogical analysis by X-Ray Diffraction (XRD) and physics of BGA and natural aggregates were carried out. Asphalt mixtures with the incorporation of BGA were produced based on Marshall dosing procedures, embodied in the National Department of Transport Infrastructure (NDTI) standards. At the end of the work, it was verified that the mixes of concrete with 2% and 8% of BGA presented the best values for the volumetric parameters and Marshall stability, so that they were superior to those recommended by the Brazilian technical standards. In addition, the results of the physical, chemical and mineralogical characterization revealed values compatible with the natural aggregates used in paving works in the country. Thus, it is concluded that the use of BGA presents itself as an alternative material to be used in the composition of (HMAC), meeting the technical criteria required by Brazilian agencies, in addition to providing advantages from an economic and environmental point of view.

The approach to the thermal performance of buildings has been a recurring theme in the space of scientific research after the development of the performance standard, NBR 15575 (ABNT, 2013). It seeks to improve the thermal performance of buildings mainly through the use of passive cooling techniques in the envelope through cementitious materials that acquire insulating properties with the use of additives that directly or indirectly allow the incorporation of air. Therefore, the present study aims to observe the influence of the use of hydroxypropylmethylcellulose (HPMC) on the thermal and mechanical properties of coating mortars with the addition of 0%, 0.015%, 0.030%, 0.045%, 0.060%, 0.090% of HPMC . To determine the properties of the fresh and hardened state of the mortars, tests were carried out on compressive strength, flexural strength, water absorption by immersion, mass density, modulus of elasticity and water loss by evaporation. The results indicate that the addition of HPMC causes an increase in the void index of the material, resulting in a reduction in the mechanical strength and modulus of elasticity. It is also noted that the incorporation of the additive produces a mortar with lower mass density, resulting in a lighter material and possibly with better thermal properties.

Coastal agents such as waves, nearshore currents, winds and tides are capable of transporting sediments from one place to another, to generate a positive or negative sediment balance in coastal areas. Ponta Negra beach and part of Via Costeira in Natal/RN suffer erosion and their sediment supply is compromised due to disorderly urbanization from the 1990s onwards. Several problems were installed on the beach caused by the energy of the waves, which no longer had space to dissipate, since urbanization advanced on the beaches and solidified an environment that was still part of a dynamic process. As it is one of the biggest tourist places in the city of Natal, the region attracted the government's attention to the elaboration of a beach recovery plan with the implementation of new coastal defense works: sediments replacement, containment structure and adequacy of the rainwater drainage system that flows into the beach face. This work analyzes the coastal erosion status and evaluates the coastal defense works implemented and in planning at Ponta Negra beach and Via Costeira. Making use of satellite images, LANDSAT and Sentinel-2, and geoprocessing tools such as CASSIE and QGIS, it was possible to perform the automatic extraction of shorelines and verify the sedimentary balance in area in the long (last 30 years) and medium term (last 06 years) area. The study also analyzes the pathologies of the coastal protection works installed since 2012 and the weaknesses that they will cause to the process of fattening the beach. With geoprocessing, Ponta Negra Beach faces continuous erosion and the Via Costeira is still a region considered stable. About beach recovery projects, there is a lack of integration and harmony between them, which favors the emergence of flaws in the definition of relevant points for the proper functioning of the recovery work.

Dams are extremely important, and it is necessary to guarantee their integrity and stability in adverse conditions, exemplified by earthquakes. The seismic evaluation can be carried out by several methods, highlighting the pseudo-static methodology. The applicability of this method depends on the ability to define representative horizontal and vertical reference levels. In Brazil, the ANA allows the application of fixed coefficients, defined disregarding seismic regionality. The northeast region of Brazil presents a relevant seismic risk, having the Açu dam as one of its most important dams. Pseudo-statics were analyzed with the Açu dam, adopting determination decisions in different ways. When inclined to those suggested by ANA, the dam showed stability, with FS close to 1.4. However, when applied the methodology proposed by Cruz et al. (2021), the dam has evaluable stability considering return times of 475 and 975 years, and evaluable instability considering return times of 2,475 and 10,000 years. It was noticed that verification by the ANA is capable of representing smaller scale events, which may not guarantee an adequate level of safety depending on the location in Brazil, suggesting the use of other methodologies to define these homologation coefficients in dams.

The Brazilian semi-arid region suffers from water scarcity in much of its territory. In this way, it is necessary to use several alternatives of water sources so that there is a balance between demand and water supply, in addition to seeking to increase its availability. The use of Rainwater Storage Systems (SAAC) has been widely adopted to increase water supply, especially in regions with high water shortages and irregularities in the distribution of precipitation. The study will be implemented for several locations inserted in regions with homogeneous rainfall regimes in the State of Rio Grande do Norte. Thus, taking these factors into account, the present work aims to analyze the temporal characteristics of the rain that occurs in each homogeneous area and to verify the efficiency of the water storage system for different combinations of demand, water catchment area and volume of water. reservoir. In addition, an analysis will be made for different rules of water supplementation by an external source supplied by water trucks in dry periods and, thus, seek to propose measures to increase the efficiency of the rainwater storage system (SAAC) characterized by the cistern. In this way, it will be possible to verify the influence between the factors of reservoir volume, roof area, water demand for human consumption and frequency of water supply from the water truck, on the efficiency of the system.

The use of rainwater in homes is used as an attenuator of the problems of low water demand, especially in semi-arid or remote regions. This research has the general objective of analyzing the effects of epistemic uncertainties on the water balance of cisterns located in the Brazilian semi-arid region. Thus, to achieve this objective, the Monte Carlo Simulation method was applied, having as input variables the reservoir volume, water demand, catchment area and rainfall, under the effects of climate change, and as a variable output, the performance index called volumetric cistern reliability. For the consideration of climate change, two distinct periods were considered: the recent climate (1979 – 2005) and the future climate (2023 – 2052), using three Global Climate Models, under two radiative forcing scenarios (RCP 4.5 and CPR 8.5). The obtained results indicate low volumetric reliabilities in all simulations, however, even with all the uncertainties, both in the recent climate and in the future climate, the highest efficiency indexes are obtained with the observed precipitation data. The highest frequency of simulations that reached a reliability of 90% occurred for the recent climate, with the observed data, and the lowest frequency happened for the future climate with one of the models under RCP 4.5, however, greater differences are found for lower efficiencies .

Water erosion is a natural phenomenon that can separate the soil into smaller particles, being transported by surface runoff to deposition in more flattened areas. Soil use and management based on conservation practices reduce the effects of water erosion and can be evaluated using hydrosedimentological modeling. Studies in this area are essential to analyze impacts of change and land use and/or desertification, which expands significantly in the Brazilian semi-arid region. In this sense, the objective of this work was to evaluate the effects of two widely used conservationist practices, terracing and dams, in the containment of erosion and sediment production in the hydrographic basin of the Seridó river. The tool used in this analysis was hydrosedimentological modeling, where three numerical experiments were carried out: (1) control (CNTRL), where natural soil cover and long-term desertification were represented; and scenarios of soil conservation practices: (2) terracing (TERR) and (3) dams (BARR). In general, dams (BARR) showed greater efficiency in reducing erosion and sediment production compared to the efficiency of terraces (TERR), 47% more effective, where sediment production, respectively, was equal to 0, 8 ton/ha/year and 1.2 ton/ha/year, compared to the control scenario (CONTRL), where it was 3.2 ton/ha/year. Terracing and dams considerably reduced soil loss in a watershed undergoing desertification. These practices should also be evaluated in the field, experimentally, in order to assess their applicability in the process of mitigating soil loss due to desertification, as well as calibrating and validating hydrosedimentological models. Advances in this area can help guarantee food security and water quality in the Brazilian semi-arid region.

LC³ (Limestone Calcined Clay Cement) mortars with different Portland cement contents (PC) (100%, 55%, 50%, 45%, and 40%) and a combination of metakaolin (MK) and limestone filler (LS) (0%, 45%, 50%, 55%, and 60%) in a 2:1 ratio were evaluated regarding their fresh, hygroscopic, mechanical, and thermal properties. LC³ mortars with as low as 40% Portland cement contents satisfied the normative requirements for applying on walls and ceilings. In addition, the incorporation of MK and LS for reducing PC consumption generated mortars with lower densities, reflecting in lighter materials with improved thermal insulation capacity with a reduction up to 4 ºC of the equilibrium plateau temperature for mortars LC³ – 55, LC³ – 50, LC³ - 45, and 2.5 ºC for the mortar with the lowest PC content (LC³ - 40).

The mechanical behavior of a saprolitic soil, originating from gabroic rock formations covering an area of approximately 31 km² in a semi-arid region of Brazil, was investigated. The study involved the collection of data from petrographic, chemical (XRF), and mineralogical (XRD) analyses, as well as a series of physical (geotechnical characterization and compaction), hydraulic (permeability), and mechanical (triaxial and consolidation) tests. The results indicated that the soil originates from a gabronorite and exhibits non-plastic behavior, low permeability and low compressibility, with SUCS classification of SW-SM. During compaction tests, the soil displayed a propensity for grain breakage; however, it was not possible to fully characterize this phenomenon within the scope of the conducted tests. The mechanical tests revealed that the yield stress imposed by compaction made the soil's behavior resemble that of an overconsolidated soil. This led to the generation of negative pore pressures, increasing the soil's strength in undrained tests, and a dilatant behavior in drained tests, where the dilatant tendency decreased as the effective confining stress increased. Under higher confinement stresses, the behavior shifted to a contractive state, and reaching peak strength was followed by a significant reduction in strength due to the continuous increase in positive pore pressure – an unfavorable trend for certain geotechnical applications, as it indicates a predisposition to static soil liquefaction under confining stresses exceeding the critical threshold.

The propagation characteristics of microwave signals, such as power loss and speed, in buildings significantly determine the operational performance of mobile devices inside buildings. These characteristics are determined by the electrical properties of the walls that make up the masonry of these buildings. Most current communication is carried out through signals that propagate wirelessly and can suffer interference in environments built with different materials, which is a relevant problem, especially in smart buildings. Therefore, evaluating the power loss caused by the main materials used in masonry, as well as the electrical properties of these materials, is fundamental for the design of indoor wireless communication links. In this sense, this research aims to evaluate the attenuation of microwave signals and the electrical properties of different materials used in building masonry (ceramic blocks, concrete blocks and plaster walls). Three wall samples were produced from each of these materials for characterization purposes regarding their structure, microstructural organization and electrical properties. The attenuation in the wireless signal caused by each type of material, and the electrical properties such as electrical permittivity, shielding efficiency and electrical conductivity were determined using an experimental measurement scheme proposed in this work. Average values for attenuation coefficients as a function of frequency for the operating range of the main 5G and Internet of Things (IoT) services were obtained. Furthermore, the dependence of wireless signal attenuation on the type of material and its composition and the influence of the type of wall covering on signal attenuation were evaluated. The results indicated that walls made of ceramic blocks caused the greatest attenuation of the signal, among all types of masonry analyzed; while plaster walls were those that caused the least attenuation. When comparing non-structural block masonry, it appears that cement block walls showed lower attenuation when compared to ceramic block walls. After analyzing the micrographs of the ceramic and cement blocks, it can be stated that the higher the void index and the porosity of the material the wall was manufactured from, the lower the value of its electrical permittivity and consequently the lower the attenuation caused in the wireless signals in today's commercial service bands.