Uso de papel kraft em compósitos de concreto: uma alternativa inovadora e sustentável

Abstract

The construction industry is one of the sectors that most contributes to job creation in Brazil, representing a significant share of the Gross Domestic Product (GDP). In 2024, according to data from the Brazilian Institute of Geography and Statistics (IBGE), the sector showed a growth of 4.1%, reinforcing its economic and social relevance. However, this growth is accompanied by significant environmental impacts, especially due to the high energy consumption and the generation of solid waste, such as plastics and papers from packaging materials, especially cement. The improper disposal of these materials has exacerbated urban environmental problems, making the search for more sustainable solutions urgent. Given this reality, this study proposes the reuse of Kraft paper, originating from cement packaging, in concrete production, through the extraction and incorporation of cellulosic fibers. The main objective is to evaluate the performance of concretes modified with different contents of these fibers (0.0%, 1.5%, 2.5%, 5%, and 10%, in relation to the total mass), focusing on the application in non-structural precast elements. The Kraft paper underwent a simple physical treatment to obtain the fibers, which were then incorporated into the concrete mixtures. Compression strength, slump test, absorption, and granulometric analysis tests were carried out after the curing period. Preliminary results indicate that the addition of Kraft paper fibers is technically feasible, maintaining or even improving the mechanical performance of the concrete in certain proportions. In addition to contributing to the reduction of waste disposal and the use of conventional raw materials, the proposal reinforces the potential of the construction sector to adopt environmentally responsible practices. It is concluded, therefore, that the incorporation of cellulosic waste into concrete represents a promising alternative to combine sustainability, innovation, and efficiency in construction.