Session: 12-03: Structural Health Monitoring III

Paper Number: 149414

149414 - Self-Sensing 3d Printed Cementitious Materials Using Carbon Microfibers for Strain Measurement 

Abstract: 

3D printing technology is rapidly gaining popularity in civil engineering, because it can be used to automate fabrication through a layer-by-layer process providing a new realm of geometric flexibility and construction speeds. Yet, its widespread application is impeded by the individual nature of the builds, often yielding an unacceptable level of uncertainty when targeting structural applications. Of interest to this paper is the real-time monitoring of 3D printed concrete structures. The aim is to produce capabilities to locally functionalized 3D printed materials to empower strain sensing and thus quality monitoring. This is done through the integration of cementitious sensors during the printing process. The interest in cement-based sensors possessing self-sensing properties has grown significantly in the research community in the last decades. Its promise is in its application to structural health monitoring strategies, where the sensor can be organically embedded within cementitious structures and provide extremely robust monitoring capabilities. In this paper, we study the 3D printing of functionalized cementitious materials with strain sensing capability. The sensor is a conductive cement composite produced by adding graphite and carbon microfibers to cement, in quantities enabling electrical percolation for enhanced piezo-resistivity. A customized 3D printer was fabricated to print the specimens, and a technique was developed to integrate two copper meshes in parallel during the printing process to act as electrodes. The resistivity and strain sensitivity were experimentally characterized. Results show that the proposed 3D printed conductive cement composite is capable of strain sensing, enabling direct integration within a 3D concrete printing process.

Presenting Author: Han Liu Department of Civil, Construction, and Environmental Engineering, Iowa State University

Presenting Author Biography: Han Liu
Postdoctoral researcher
Dept. of Civil, Construction and Environmental Engineering
Iowa State University
Town Engineering, 813 Bissell Road
Ames, IA 50011
Phone: (515) 294-2140
E-mail: liuhan@iastate.edu

Authors:

Han Liu Department of Civil, Construction, and Environmental Engineering, Iowa State University
Simon Laflamme Department of Civil, Construction, and Environmental Engineering, Iowa State University
Antonella D'alessandro Department of Civil and Environmental Engineering, University of Perugia
Filippo Ubertini Department of Civil and Environmental Engineering, University of Perugia