Self-healing concrete marrying ancient Roman knowledge and Te Ao Māori
Dr Enrique del Rey Castillo from Waipapa Taumata Rau the University of Auckland aims to make a sustainable alternative to concrete with a reduced carbon footprint, inspired by Roman construction and mātauranga Māori
Published on 2 Whiringa-ā-rangi November 2023
Global carbon dioxide emissions must be reduced by 45% by 2030 to prevent severe climate effects. Production of Ordinary Portland Cement (OPC), a major component of concrete, accounts for 5-8% of global greenhouse gas emissions. Ancient Roman concrete, made with lime and volcanic gravel such as pumice, has a comparatively smaller carbon footprint and is also thought to have “self-healing” properties, where small cracks can close themselves. Modern concretes made with similar materials may therefore be an effective, sustainable alternative to concretes made with OPC.
Dr del Rey Castillo has received a Marsden Fund Fast-Start grant to develop a concrete alternative using materials abundant in Aotearoa New Zealand – volcanic ash (pumice) and kaimoana seashells. Both materials have been used for many purposes by Māori in the past, but neither have been tested thoroughly for their potential in concrete production. Dr del Rey Castillo and their team will investigate the unique material properties of pumice from the rohe of Te Arawa and seashell powder from Ngātiwai aquaculture farms and determine their suitability as partial cement replacements. They will then investigate whether concrete made from these materials displays any of the “self-healing” properties of ancient Roman concrete. This research plan will be carried out with ongoing input from mana whenua, who are impacted by the polluting industry of concrete production and who stand to benefit from sustainable use of these natural resources.
By marrying ancient Roman knowledge and mindful use of our taonga, this project aims to produce a sustainable concrete that reduces carbon emissions for the benefit of Aotearoa and beyond.