The reuse of glass bottles in earthen wall construction as a sustainable solution to mitigate the housing deficit in Brazil

Abstract

The recycling rate of glass waste in each country and continent depends on several complex factors. Economic wealth, fertility rate, environmental taxes, and R&D expenditures positively affect recycling and circularity rates. However, nation size and logistical obstacles are important in glass recycling. In countries such as Brazil and the USA, the distance between material recovery facilities and cullet suppliers tends to be greater than in European countries, discouraging recycling. On the other side, container glass is omnipresent and its reuse as building components is found worldwide. Across the globe, glass bottles combined with earthen walls have been already used in small-scale structures. There's a prevalent trend of placing bottles horizontally in walls to ensure stability and light passage. Most of these projects are developed by individuals with creative and practical backgrounds, who conceive and construct these projects themselves, without the assistance of experts. Yet, comprehensive data on the properties and performance of such constructions remains limited. In 2021, H. Alkisaei from CEG/ TU Delft started investigating the reuse of glass bottles as a building material. Alternative assemblies of multiple glass bottles were tested, and a glass bottle column prototype was presented, showing its feasibility for small-scale structural applications. After, CEG's master student Hanna Heller started investigating the use of glass bottles in walls bound by a self-compacting earth-based mortar. Brazil lacks detailed information on glass recycling. According to the Ministry of the Environment, over 1 billion glass bottles are yearly discarded in the country. In contrast, only 20 to 25% of glass consumed is recycled. For these reasons, Brazil became a case study in Hanna's thesis, where many glass bottles are improperly disposed of, and the public sector has recognized the urgency to reuse them in different applications. On the Brazilian side, Dr. Eduardo Bellini Ferreira, Assistant Professor at the Department of Materials Engineering of the Engineering School of São Carlos, University of São Paulo (SMM-EESC/USP), has been working with different approaches for recycling glass wastes as well as mineral wastes into vitreous materials. There is mutual interest and complementarity between the Brazilian and Dutch groups. Thus, this proposal aims to explore the reuse of glass bottles in earthen wall construction, validate the results obtained in developing bricks using Dutch soil and glass bottles, and understand the differences in the properties of these bricks and bricks fabricated with Brazilian soil. A formal collaboration between TU Delft and FAPESP researchers will address sustainability in both countries. Furthermore, it can potentially impact the lives of individuals living in inadequate housing conditions in Brazil. (AU)