Bio-based materials to reduce non-renewable resources use in construction: a products’ analysis

Considering the high quantities of raw materials consumed by the European construction sector, it becomes increasingly important to implement the Circular Economy Action Plan as proposed in 2020. Within this EU context, the Italian case is an important one as it is estimated to extract 317 million tonnes of raw materials each year, which are mostly used in the construction sector. Starting from these premises, this contribution wants to explore new ways of avoiding raw materials exploitation by considering the actual benefits of using renewable ones as alternatives to more consolidated construction components. To reach this aim, at first renewable and bio-based materials are defined and framed in order to understand their differences and set the basis of the research. Based on this framing the focus of the research is mainly on bio-based materials, and this allows to deeper analyse the Italian product market to search for the available products. Secondly, the searched products are systematised in a database that gathers all their characteristics, and four bio-based materials were chosen for deeper analysis. These materials are hemp, wood fibre, cork and rice waste, and a total of 256 building products are presented. The collected data show that the four bio-based materials examined are usually combined with other components of other origin, in particular mineral – the most frequent elements are hydraulic and aerial lime and Portland cement, synthetic – like resins and polyester fibres, or natural ones – such as natural additives, jute and cellulose. This means that only 56 out of 256 products are made from bio-based material alone, while 78% of them consist of more than one component other than bio-based ones. Certainly, the percentages and use of non-renewable materials in these bio-based products is more limited than in fully non-bio ones, but the aggregation of different elements – both bio-based and non-bio-based ones – leads to issues linked to the use of exhaustible resources and difficulties in recycling the products at their end-of-life. This research wants to find ways both to move towards the substitution of non-renewable materials within bio-based products to further implement and change the building material production chain, and to find ways of better designing the end-of-life of these products, trying to foresee their reuse.