Microstructure and water absorption of ancient concrete from Pompeii: An integrated synchrotron microtomography and neutron radiography characterization

• Published in: Cement and concrete research Vol. 139; p. 106282
• Main Authors: Xu, Ke, Tremsin, Anton S., Li, Jiaqi, Ushizima, Daniela M., Davy, Catherine A., Bouterf, Amine, Su, Ying Tsun, Marroccoli, Milena, Mauro, Anna Maria, Osanna, Massimo, Telesca, Antonio, Monteiro, Paulo J.M.
• Format: Journal Article
• Language: English
• Published: Elmsford Elsevier Ltd 01.01.2021; Elsevier BV; Elsevier
• Series: Cement and Concrete Research
• Subjects: Absorptivity; Adsorbed water; Chemical Sciences; Concrete; Crack propagation; Ductile fracture; Durability; Environmental impact; Fracture; Image analysis (B); Machine learning; Material chemistry; Microstructure; Microtomography; Mortars (material); Neutron radiography; Percolation theory; Pore size distribution; Pore structure; Porosity; Portland cements; Radiography; Roman concrete; Synchrotron microtomography; Synchrotrons; Tortuosity; Transport properties; Transport properties (C); Water absorption; Water distribution; Water engineering; Neutron radiography; Synchrotron microtomography; Pore structure; Machine learning; Fracture; Image analysis (B); Transport properties (C); Roman concrete
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2020.106282

There is renewed interest in using advanced techniques to characterize ancient Roman concrete due to its exceptional durability and low-carbon footprint. In the present work, samples were drilled from the “Hospitium” in Pompeii and were analyzed by synchrotron microtomography (μCT) and neutron radiography to study how the microstructure, including the presence of induced cracks, affects their water adsorption. The water distribution and absorptivity were quantified by neutron radiography. The 3D crack propagation, pore size distribution and orientation, tortuosity, and connectivity were analyzed from μCT results using advanced imaging methods. Porosity was also measured by mercury intrusion porosimetry (MIP) as a reference. Ductile fracture patterns were observed once cracks were introduced. Compared to Portland cement mortar/concrete, the Pompeii samples had relatively high porosity, low connectivity, and a similar coefficient of capillary penetration. In addition, permeability was predicted from models based on percolation theory and pore structure data to evaluate the fluid transport properties. Understanding the microstructure of ancient Pompeii concrete is important because it could inspire the development of modern concrete with high durability.