Resumo A produção de resíduos industriais causa impactos ambientais, por isso é importante reintroduzi-los no ciclo produtivo para promover um desenvolvimento mais sustentável. O presente estudo teve o objetivo de investigar o uso do pó de mármore residual como fíler e seus efeitos na produção de concreto para pavimentos intertravados. Para isso, a areia natural foi substituída em 15% e 25% pelo pó de mármore, percentuais pouco usados na literatura de reaproveitamento de resíduos de mármore. Foram avaliadas as propriedades físicas dos materiais utilizados e as características mecânicas e microestruturais dos concretos desenvolvidos. Notou-se que o pó de mármore melhora a trabalhabilidade da mistura e reduz a quantidade de vazios no concreto, resultando em um material mais resistente, denso e homogêneo. As resistências à compressão obtidas pelos concretos foram próximas de 40 MPa, o que atende à norma técnica brasileira para produção de pavimentos intertravados. Verificou-se que a inserção de resíduos no ciclo produtivo é benéfica por otimizar propriedades dos materiais, reduzir o consumo de matérias-primas e os impactos ambientais associados à sua extração.

This study investigates the use of iron ore tailings (IOTs) as recycled aggregates in segmental blocks, focusing on technical performance, CO₂ emissions, and embodied energy using the cradle-to-gate approach. IOTs replaced fine aggregates in concrete at 25%, 50%, and 75% by volume, achieving compressive strengths of 16.23 MPa, 10.02 MPa, and 3.93 MPa, respectively. Raw material production accounted for 98% of CO₂ emissions and 86% of embodied energy. Producing blocks at mining sites offered limited environmental benefits due to longer transport distances. Despite this, the results showed a 6% reduction in CO₂ emissions and a 35% improvement in mechanical–environmental performance (CO₂ emissions weighted by compressive strength) compared to traditional concrete. These findings underscore the potential of IOT-based concrete for segmental block production.

The mining and steelmaking industries, while vital for economic and social development, produce and dispose of waste that contributes to environmental instability and discomfort. In this context, this study aimed to develop novel polymer composites intended for Artificial Ornamental Stone (AOS) application by incorporating iron ore tailings (IOTs), quartzite waste (QTZ), and steel slag (SS) into an epoxy (EP) matrix. The chemical, mineralogical, physical, mechanical, morphological, and thermal properties of the materials were assessed. Three waste mixtures were proposed using the Modified Andreassen Curve method, each with 35, 45, and 55 v/v% of EP. The composite properties were evaluated, showing that the composite with QTZ, SS, and 55 v/v% EP exhibited the lowest porosity (0.3%), water absorption (0.1%), and highest flexural strength (41 MPa). The composite containing the three wastes with 55 v/v% EP presented 1.0% porosity, 0.4% water absorption, and 34 MPa flexural strength. Lastly, the composite with IOTs, QTZ, and 55 v/v% EP exhibited 1.1% apparent porosity, 0.5% water absorption, and 23 MPa flexural strength. Therefore, the polymer composites developed with IOTs, QTZ, SS, and EP demonstrated suitable properties for wall cladding and countertops, presenting a potentially sustainable alternative to reduce environmental impacts from the mining and steelmaking industries.

The increasing demand for disposable textile products, personal care items, and electronic commerce has led to a substantial rise in waste generation, particularly from nonwoven fabric masks (wNWFs) and corrugated cardboard (wCC). This study assessed the feasibility of utilizing these waste materials, which were produced in significant amounts during the COVID-19 pandemic, as both a matrix and reinforcement filler in wood–plastic composites (WPCs). The WPC was fabricated using either two extrusion cycles or thermokinetic homogenization, with both processes being followed by hot pressing. The formulations consisted of virgin polypropylene (vPP), wNWF, and wCC in proportions of 45, 45, and 10 wt %, respectively. The results demonstrated that the composites produced via two extrusion cycles exhibited a tensile strength that was 85% higher and three-point flexural strength three times greater than those produced through thermokinetic homogenization. These findings contribute to advancements in scientific and technological knowledge and offer an efficient solution for managing these types of waste, which continue to be generated post-pandemic.

The SARS-CoV-2 Coronavirus pandemic and the rise in climate disasters have fueled a surge in disposable mask production, exacerbating waste challenges. The study proposes a sustainable pathway for recycling Non-Woven Fabric (NWF) originating from masks made of Polypropylene (PP) used as Personal Protective Equipment (PPE). Eco-friendly blends of virgin polypropylene (vPP) and recycled non-woven fabric (NWF) were produced through extrusion, and the physicochemical and mechanical properties of the blends were evaluated. The addition of NWF resulted in lower tensile and flexural strengths than vPP. However, from 50%wt of recycled NWF, the blends proved to be as stiff as, or even stiffer than, the virgin polymer. While slightly lower, the 50%wt NWF blend achieved properties close to those of vPP, making it the ideal composition for replacing PP in conventional applications. This approach offers a sustainable solution for mask recycling, reducing disposal impacts and supporting a circular economy.

This paper reviews recent advances in wood-plastic composites (WPC) research to explore their potential in composite structures. Utilizing the Systematic Search Flow methodology, the composition, production strategies, and physical-mechanical performance of WPC were analyzed. The extrusion process, whether isolated or combined with other methods, stands out for thermoplastic-based WPC, allowing continuous production and high processing rates. Polypropylene is commonly used as a matrix, combined with residual fibrous fillers that enhance stiffness and strength but also increase water absorption. The use of compatibilizing agents can mitigate this absorption and improve mechanical performance. The manual hand layup method is prevalent for thermoset composites, offering longer handling times and resulting in dimensional stability and thermal resistance; however, it heavily relies on the operator's skill, limiting process consistency. The versatility of WPC positions them as a promising solution for construction, addressing plastic waste pollution and deforestation. Nonetheless, further research is needed to enhance durability and performance while exploring new materials and techniques. This study comprehensively covers these aspects, employing graphical tools to illustrate the complexities involved and providing in-depth analyses of how these factors influence the physical-mechanical behavior of WPC.