Mayra Deberg - [material research]

year: 2022 - current | terrazzo with building waste

porto, portugal | master's thesis

The construction industry is recognized as one of the most polluting sectors worldwide, with substantial environmental, social and economic impacts throughout its production process. Construction and demolition waste (CDW), which makes up around a third of global waste, is a significant challenge, especially in urban areas.

Effective resource management, focusing on the efficiency of raw materials and the reuse or recycling of waste materials generated by the construction industry, is essential to reduce its impact and promote circularity. With this in mind, this research, which was carried out as part of a master's thesis at the Faculty of Fine Arts of the University of Porto, aimed to explore strategies for minimizing construction waste through the reuse and recycling of materials for applications in product design.

The case study took place in the metropolitan area of Porto, Portugal and as a practical result of the research, the “Fragments of the Past” project was developed, a circular material made up of construction and demolition waste and granite powder, which reinterprets the traditional terrazzo technique.

[materials]

[samples]

[products]

Building waste is made up of a wide variety of materials, from wood, metals and plastics to concrete and bricks. It is estimated that over 90% of this waste has the potential to be used as a resource and substitute for construction materials, however high-quality recycling opportunities are often overlooked.

This project, which explored the feasibility of applying this waste to materials and products, integrated construction and demolition waste collected from various sources in the study area, such as waste collection and management centers, waste management operators and construction sites. By-products from ornamental stone companies (namely marble and granite) were also collected in this process. The collection of waste at different collection points was explored in order to explore the potential for integrating processed and unprocessed materials.

In this process, it was possible to understand the complete life cycle of waste, not only providing information on waste production and its management, but also enabling the creation of a collaborative network between academia and industry.

From an economic perspective, this collaboration between the construction, recycling and academic sectors has contributed not only to environmental sustainability, but also to operational efficiency and cost savings for the participating companies.

[collaborators: university of porto - faculty of fine arts + lipor; tcc whitestone; costa almeida ambiente; felisberto mármores e granitos; forma abstracta; grampedra]

[waste collection and management centers]

[waste management operators]

[granite company]

[marble company]

At this stage, an experimental plan was drawn up with four phases. In the first phase, after collection, the
waste was sorted and separated according to type. Manual sorting was carried out according to the origin
and composition of the waste, identifying materials such as concrete, bricks, ceramics and other waste from construction and demolition. This initial separation was carried out with the aim of ensuring the homogeneity of the processed material, which facilitates quality control in the following phases. After sorting, the materials went through the manual crushing stage, a process which involved using sledgehammers to break up the larger pieces of waste on a metal base. The shredding resulted in fragments of different granulometries, which were classified according to their approximate size: grade 1 (up to 5 mm), grade 2 (between 5 mm and 15 mm) and grade 3 (between 15 mm and 25 mm). Tests were then carried out with the materials collected, but without rigor in calculating the percentage of aggregates.

[waste]

[waste processing]

[waste samples]

In the second phase, in order to explore the possibilities generated by the waste, experiments were carried out with the various residues collected associated with different types of binders, such as cement, resin and lime. In addition, marble dust and granite dust were applied (separately) as a mixing base, with the aim of reducing the virgin aggregates integrated into the composition. During this phase, different grain sizes were used in order to observe the aggregation of the waste in the mixture. Also in order to analyze their aesthetic effect, all the samples were sanded and polished, but no surface coating was added.

[the second phase]

In the third phase, there was a development of experiments and intermediate characterization, with new experiments being carried out with the composition selected at the end of the second phase. At this stage, different proportions were explored between the waste and the incorporated binder, cement, granite powder and fragments of CDW. Due to its physical and qualitative characteristics, the mixture selected to continue the experiments and final characterization was the one incorporating 20% cement, 30% granite powder and 50% CDW fragments (without adding additives).

In the fourth phase, experiments were carried out with the final composition chosen, carrying out tests covering various aggregates and pigmentations in order to define one or more textures to be applied to the final product.

[the third phase]

[the fourth phase]

Once the composition was complete, the material based on the reinterpretation of the traditional terrazzo technique, originally conceived by Venetian builders as a low-cost, flexible and sustainable material, was used in different design proposals, highlighting its versatility.

The process of designing the pieces was entirely handmade, from the production of the molds - in silicone or plaster - to the final manufacture and finishing. The stages included grinding the waste aggregates into specific granulometries, developing a composition to be cast in reusable molds and the detailed finishing of the pieces, which underwent sanding processes and/or the application of surface coatings.

[crushing waste]

[mix the composition]

[sanding or polishing]

The pieces developed sought to value and recover the history behind construction and demolition waste.
The aim was to highlight the material as a prevalent element in the objects, with a view to a strategic choice and application of materials, which represents one of the most influential and functional means of communication between products and their users.