Innovative Thermal Renders Incorporating Oyster Shells for Sustainable Insulation

Abstract

In accordance with current sustainable development objectives, it is intended to implement innovative and sustainable solutions at economic, environmental, and functional levels, boosting the construction sector to increasingly contribute to society. Expanded cork is an alternative to sand aggregate in improving the thermal insulating properties of renders. In addition, other materials can be incorporated as aggregates in an attempt to contribute to both the improvement of the physical characteristics that the render must fulfil as well as the improvement of thermal behaviour (if possible). In this sense, bio-based materials generated by the aquaculture sector, such as oyster shells, can contribute as a bio-based insulation material for thermal renders. In this study, thermal natural hydraulic lime mortars were produced from a mixture of expanded cork (EC) insulating aggregate and oyster shells (OSs). The percentages of replacing EC by OSs were 20, 30, 40, and 50%. The tests were carried out in fresh and hardened states. The studied mortars presented a thermal conductivity and compressive strength of 0.151 W/(m·K) and 0.63 MPa, respectively. The most interesting performance between thermal conductivity and compressive strength was for the composite with 50% of each bio-based material. The potential of incorporating oyster shells as a bio-based insulation material could contribute to a sustainable blue circular economy.

Sustainable Retrofitting Solutions: Evaluating the Performance of Jute Fiber Nets and Composite Mortar in Natural Fiber Textile Reinforced Mortars

“…Considering environmental and ecological sustainability, different research groups have studied the recyclability of C&D wastes [6][7][8][9][10][11][12] for various C&B applications. Similarly in the literature, the use of argo-wastes also can be found in [6,[13][14][15][16][17][18].…”

Blue Circular Economy—Reuse and Valorization of Bivalve Shells: The Case of Algarve, Portugal

“…Shells are often considered nuisance waste rather than a valuable commodity, resulting in them being dumped in landfills or incinerated. Promoting the circularity of this waste is crucial to achieving environmental, economic, and socio-cultural benefits [25], beyond researching solutions for this waste, which can be applied across various sectors including construction, cosmetics manufacturing, artificial stone production, food supplement production, insulation material in thermal renders, agriculture, livestock farming, soil recovery, water and effluent treatment, as well as animal feed formulation [16,[26][27][28][29][30][31][32][33][34]. The tradition of using oysters in civil construction dates back to ancient times, since the 16th century, rooted in the history of coastal regions, where the local population benefited from local resources for construction needs [35].…”