New reinforcement techniques are protecting historic buildings, benefiting society and the economy

Historical buildings are of great value to society, contributing to tourism, infrastructure and a community’s social identity. Protecting and preserving them for the future is important, but also a challenge. Ideal restoration and reinforcement methods need to be easy-to-fit to existing structures, compatible with the existing building materials, sustainable, cheap and, of course, ensure the buildings stay safe and secure in the face of climate change, frequent earthquakes and conversion to modern residential or commercial buildings. 

Dr Marco Corradi, an Associate Professor in the Department of Mechanical and Construction Engineering at Northumbria University, specialises in innovative repair and reinforcement techniques for historical buildings. Corradi’s techniques include embedding Glass Fibre Reinforced Polymer (GFRP) meshes and high-strength stainless steel cords into lime mortar between the stones, and in the mortar joints, of fragile masonry walls – a process which makes them significantly stronger (see Figure). As well as being effective, these methods are sustainable, require minimal intervention when fitted, retain the aesthetics of the building and are also reversible – meaning they can be removed if more suitable reinforcement methods are discovered.

Dr Corradi’s research has caught the attention of several Italian conservation construction engineering companies, who have worked with him to add his innovative reinforcement techniques to their product ranges. The company Fibre Net, for example, created their new RETICOLA product from Corradi’s Reticulatus reinforcement method (see Figure ). This and products based on some of Corradi’s other methods have been used in more than 8,500 reinforcement projects since 2015; work which has led to the creation of many jobs at the company and increased their annual turnover. Overall, the economic value to Fibre Net of these techniques is estimated to be 27 million Euros between 2015 and 2020. The methods have been used to protect thousands of historical buildings, including Italian primary school buildings and medieval towers and castles; sites which are now up to 80% more resistant to earthquakes and thus significantly safer for users and visitors. 

Alongside his research, Corradi has also been instrumental in training construction professionals and contributing to global recommendations and guidelines on effective and sustainable methods for strengthening masonry. As knowledge and understanding of innovative methods to protect historical buildings improves around the world, more historic assets can be preserved for future generations.