Thermal performance assessment of an 18th-century historic building in Ceará Elói Romão dos S. Souza, Brendda Karen de O. Magalhães, Magna Bocage Irineu, Laís Cristina B. Costa Journal of Building Pathology and Rehabilitation, 2026 Thermal performance refers to a building’s efficiency to maintain indoor comfort conditions in response to climate variations. It represents a key factor in the quality of the built environment. Regarding heritage buildings, their thermal performance is associated with constructive features that employ passive design strategies to reduce environmental impacts. However, current climate change intensifies thermal variations and extreme events, compromising occupant comfort, thermal performance, and physical integrity of historic buildings. This study analyzes the thermal performance of an 18th-century historic building in Ceará, aiming to understand its behavior under the local climate and identify potential improvements. The research combined technical inspection, observation of passive design strategies, mortar sampling, and computational simulation in Revit, along with physical, chemical, and morphological characterization of the material. The results indicate that the historic building exhibits stable thermal behavior, mainly due to the high thermal inertia of its original building materials. Energy simulation estimated an annual cooling consumption of 485.04 kWh, a value significantly lower than those normally reported for contemporary buildings in similar climatic conditions. Indoor air temperature and relative humidity remained within the comfort range recommended by ANSI/ASHRAE 55 (2020). Thermal comfort assessment resulted in a PMV of 0.43 and a PPD of 9%, indicating slightly warm but acceptable conditions for most occupants. These findings suggest that the passive strategies incorporated into the historic structure contribute to reducing cooling demand and promoting acceptable indoor thermal conditions.
Technical evolution of concrete in Brazil: a six-decade study (1960s–2020s) Juliana Fadini Natalli, Laís Cristina Barbosa Costa, Julia Castro Mendes, Marina Altoé Caetano, Paulo Ricardo de Matos, Alexandre Araújo Bertini, Ricardo André Fiorotti Peixoto Journal of Building Pathology and Rehabilitation, 2026
Durability assessment of a highly eco-efficient low-cement Basic Oxygen Furnace slag concrete Tainá Varela de Melo, Maria Teresa Paulino Aguilar, Laís Cristina Barbosa Costa, Juliana Fadini Natalli, José Maria Franco de Carvalho, Ricardo André Fiorotti Peixoto Revista Ibracon De Estruturas E Materiais, 2025 This paper evaluates the performance of a highly eco-efficient low-cement concrete incorporating Basic Oxygen Furnace slag (BOFS) as a raw material. The BOFS was processed to obtain fine and coarse powders, with the mix design based on a modified Andreassen method to enhance particle packing at the paste level. This approach resulted in concretes with a cement consumption of only 86.6 kg·m-3. The BOFS concretes were assessed through water absorption, ultrasonic pulse velocity, forced resonant frequency, modulus of elasticity, compressive strength, tensile strength, and pore system analysis. Additionally, electrical resistivity and accelerated carbonation tests were conducted. At 28 days, the BOFS concrete achieved a compressive strength of 35.1 MPa, corresponding to a cement intensity of 2.47 kg·m-3·MPa−1, with substantial strength gains at later ages. Despite its relatively low electrical resistivity due to the iron content, the BOFS concrete exhibited a dense microstructure (void index of 5.5% and ultrasonic pulse velocity of 4276 m/s) and remained stable under high-temperature water immersion. The optimized particle packing contributed to high mechanical performance and promising durability, as evidenced by the low carbonation depth (less than 10 mm in 120 days under 8% CO2). These findings demonstrate that highly eco-efficient BOFS concrete can achieve durability comparable to conventional Portland cement-based concretes. This study reinforces the potential of BOFS as a sustainable alternative, promoting circular economy practices and reducing the environmental footprint of the construction industry.
Sand Mining Tailings as Supplementary Cementitious Material Aline Santana Figueiredo, Augusto Cesar da Silva Bezerra, Laís Cristina Barbosa Costa, Douglas Mol Resende, Luana Drago Kuster, Ricardo André Fiorotti Peixoto Buildings, 2024 Sand mining tailing (ST) is a byproduct of the sand extraction of submerged pits, a process which is carried out to obtain aggregates for civil construction. This tailing consists of fine particles from the pulp washing process, usually disposed of in decantation ponds. The present study proposes ST as a supplementary cementitious material (SCM) for Portland cement concrete, thereby reintegrating this tailing into the production chain. In this sense, ST was characterized, and concretes containing 2% to 14% of cement replacement (%vol) by ST were produced and evaluated. STs showed natural fineness, particles with angular morphology, a significant amount of kaolinite, and 36% amorphous content. ST concretes exhibited a compressive strength of up to 57.9 MPa at 28 days under 7.0% of cement replacement, 38.8% higher than the reference. Consequently, only 5.6 kg/m3 of Portland cement was required to attain 1.0 MPa, representing a 33.6% reduction compared to the reference. The ultrasonic pulse velocities measured in ST concrete with 2.0%, 4.0%, 7.0%, and 14.0% cement replacement were 3.0%, 6.1%, 9.3%, and 6.6% higher than the reference, respectively. These results indicate enhanced mechanical properties, improved matrix uniformity, and superior environmental performance across all SCM levels compared to the reference, with optimal efficiency observed at 7.0% ST content.
Sustainable Structural Lightweight Concrete with Recycled Polyethylene Terephthalate Waste Aggregate Douglas Mol Resende, José Maria Franco de Carvalho, Bárbara Oliveira Paiva, Gustavo dos Reis Gonçalves, Lais Cristina Barbosa Costa, Ricardo André Fiorotti Peixoto Buildings, 2024 Plastic is a widely consumed material with a high decomposition time, occupying significant space in landfills and dumps. Thus, strategies to reuse plastic waste are imperative for environmental benefit. Plastic waste is a promising eco-friendly building material for cement-based composites due to its reduced specific gravity and thermal conductivity. However, this waste reduces the composites’ mechanical strength. This work aims to produce and evaluate lightweight concretes made with only lightweight aggregates and mostly recycled plastic aggregates. Initially, an optimized dosage approach for lightweight concrete is presented. The mixture proportion of the lightweight concrete was based on the performance of mortars with the complete replacement of natural aggregate by recycled polyethylene terephthalate (PET) aggregates. The PET aggregates showed irregular shapes, impairing workability and providing lightweight concretes with around 18% water absorption and 21% void index. However, the concretes presented significantly low-unit weight, approximately 1200 kg/m3. This work presented a structural lightweight concrete (ACI 213-R) using only lightweight aggregates and mostly plastic waste aggregate, with a compressive strength of up to 17.6 MPa, a unit weight of 1282 kg/m3, and an efficiency factor of 12.3 MPa·cm3/g. The study shows that with an optimum dosage, reusing plastic waste in concrete is a viable alternative contributing to environmental sustainability.
Mitigating the socioeconomic impacts of the mining industry through Social Technologies: Guidelines for technology transfer between universities and communities Marcela Aguiar Nogueira, Lais Cristina Costa, Douglas Mol Resende, Victor Rezende Carvalho, Júlia Castro Mendes, Ricardo André Fiorotti Peixoto Corporate Social Responsibility and Environmental Management, 2024 The mineral sector causes socioeconomic and environmental impacts on the surrounding communities. Thus, Social Technologies (STs) developed by universities are an alternative for improving the quality of life of the people affected by mining activities. STs are a Latin American practice comprising solutions for social inclusion and economic development. Thus, this article critically investigates the impacts of mining and STs, reinforcing the potential applications of STs in this field. Additionally, the work discusses the possibilities of technology transfer from the university to society through a comprehensive literature review, and the authors developed guidelines to mitigate the impacts of mining activities using STs implementation with technology transfer as a tool. The literature review showed that, although multiple STs aim at social inclusion, the success of the ST depends on the socio‐technical suitability of each community, an efficient training process, and the capacity for self‐management by the social actors. The guideline created includes aspects of: approach and scenario reconstruction, mapping, identification of vocations, training, and technical support for affected communities. Additionally, the mining sector can use these guidelines as a Corporate Social Responsibility tool.
Lignin-Based Admixtures: A Scientometric Analysis and Qualitative Discussion Applied to Cement-Based Composites Victor Rezende Carvalho, Laís Cristina Barbosa Costa, Bruno Eduardo Lobo Baeta, Ricardo André Fiorotti Peixoto Polymers, 2023 The development of lignin-based admixtures (LBAs) for cement-based composites is an alternative to valorizing residual lignins generated in biorefineries and pulp and paper mills. Consequently, LBAs have become an emerging research domain in the past decade. This study examined the bibliographic data on LBAs through a scientometric analysis and in-depth qualitative discussion. For this purpose, 161 articles were selected for the scientometric approach. After analyzing the articles’ abstracts, 37 papers on developing new LBAs were selected and critically reviewed. Significant publication sources, frequent keywords, influential scholars, and contributing countries in LBAs research were identified during the science mapping. The LBAs developed so far were classified as plasticizers, superplasticizers, set retarders, grinding aids, and air-entraining admixtures. The qualitative discussion revealed that most studies have focused on developing LBAs using Kraft lignins from pulp and paper mills. Thus, residual lignins from biorefineries need more attention since their valorization is a relevant strategy for emerging economies with high biomass availability. Most studies focused on production processes, chemical characterizations, and primary fresh-state analyses of LBA-containing cement-based composites. However, to better assess the feasibility of using different LBAs and encompass the multidisciplinarity of this subject, it is mandatory that future studies also evaluate hardened-sate properties. This holistic review offers a helpful reference point to early-stage researchers, industry professionals, and funding authorities on the research progress in LBAs. It also contributes to understanding the role of lignin in sustainable construction.
Study of the mechanical behavior of prisms composed by two blocks produced with electrical steel slag for structural masonry Masonry International, 2018
