Title | Geopolymer-based smart adhesives for infrastructure health monitoring: concept and feasibility |
Publication Type | Journal Article |
Year of Publication | 2011 |
Authors | He J, Zhang G, Hou S, Cai C.S. |
Journal | Journal of Transportation Research Board |
Volume | 23 |
Issue | 2 |
Start Page | 100 |
Pagination | 100-109 |
Date Published | 02/2011 |
ISSN | 0899-1561 |
Keywords | Adhesives, Cracking, Fiber optics, Geopolymer, infrastructure, Monitoring, Strain |
Abstract | This paper describes the initial efforts to explore a new application of metakaolin-based geopolymers to structural health monitoring. A distributed geopolymer-fiber optic sensing (G-FOS) system is proposed, where geopolymers are used as smart adhesives to affix optical fibers to existing in-service structures to form an integrated G-FOS sensor. Results of feasibility testing in the laboratory indicated that the tensile cracking strain of geopolymers can be controlled by finely tuning the Si/Al ratios or adding appropriate aggregate fillers such as sand, thus rendering the “smart” nature of geopolymers for deformation-based sensing. Geopolymers with SiO2/Al2O3SiO2/Al2O3 ratios ⩾3.8⩾3.8 are viable adhesives that can develop strong bond to concrete, steel, and glass fiber. Laboratory prototype testing on steel specimens under uniaxial tension and on concrete beams under four-point bending validated the concept and feasibility of the proposed G-FOS system for structural health monitoring. It further demonstrated that the G-FOS system cannot only detect overstraining events in steel but also measure the crack size in concrete. |
DOI | 10.1061/(ASCE)MT.1943-5533.0000140 |