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

May 27, 2020

Ke Xu (1,2), Anton S. Tremsin (3), Jiaqi Li (1), Daniela M. Ushizima (2,4), Catherine A. Davy (5), Amine Bouterf (6), Ying Tsun Su (1), Milena Marroccoli (7), Anna Maria Mauro (8), Massimo Osanna (9), Antonio Telesca (7), Paulo J. M. Monteiro (1)
Cornell University Archives, May 2020. arXiv:2005.13114v1


Abstract

There is renewed interest in using advanced techniques to characterize ancient Roman concrete. In the present work, samples were drilled from the "Hospitium" in Pompeii and were analyzed by synchrotron microtomography (uCT) 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 uCT results using advanced imaging methods. The concrete characterization also included classical methods (e.g., differential thermal-thermogravimetric, X-ray diffractometry, and scanning electron microscopy). Ductile fracture patterns were observed once cracks were introduced. When compared to Portland cement mortar/concrete, Pompeii samples had relatively high porosity, low connectivity, and similar coefficient of capillary penetration. In addition, the permeability was predicted from models based on percolation theory and the pore structure data to evaluate the fluid transport properties.


How Our Software Was Used

Dragonfly was used to visualize the 3D connectivity of pore networks.


Author Affiliation

(1) Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA.
(2) Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
(3) Space Sciences Laboratory, University of California, Berkeley, CA, 94720, USA.
(4) Berkeley Institute of Data Science, University of California, Berkeley, CA, 94720, USA.
(5) Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et de Chimie du Solide, Lille F-59000, France. (6) Laboratoire de Mécanique et Technologie (LMT), ENS Paris-Saclay, CNRS Université ParisSaclay, Cachan Cedex, 94235, France.
(7) Department of Environmental Engineering and Physics, School of Engineering, University of Basilicata, Potenza 85100, Italy.
(8) Head of research and innovation area of Archeological Park of Pompeii, via Plinio 4, Pompeii, NA, 80045, Italy.
(9) General Director of Archeological Park of Pompeii, via Plinio 4, Pompeii, NA, 80045, Italy.