Temperature measurement and damage detection in concrete beams exposed to fire using PPP-BOTDA based fiber optic sensors Optic Sensors

Published

September 18, 2017

Author(s)

Yi Bao, Matthew Hoehler, Fujian Tang, Christopher M. Smith, Matthew Bundy, Genda Chen

Abstract

In this study, Brillouin scattering-based distributed fiber optic sensor is implemented to measure temperature distributions and detect cracks in concrete structures subjected to fire for the first time. A telecommunication-grade optical fiber is characterized as a high temperature sensor with pulse pre-pump Brillouin optical time domain analysis (PPP-BODTA), and implemented to measure spatially-distributed temperatures in reinforced concrete beams in fire. Four beams were tested to failure in a natural gas fueled compartment fire, each instrumented with one fused silica, single-mode optical fiber as a distributed sensor and four thermocouples. Prior to concrete cracking, the distributed temperature was validated at locations of the thermocouples by a relative difference of less than 9%. The cracks in concrete can be identified as sharp peaks in the temperature distribution since the cracks are locally filled with hot air. Concrete cracking did not affect the sensitivity of the distributed sensor but concrete spalling broke the optical fiber loop required for PPP-BOTDA measurements.

Citation

Smart Materials & Structures

Volume

26

Issue

10

Pub Type

Journals

Download Paper

https://doi.org/10.1088/1361-665X/aa89a9

Local Download

Keywords

concrete crack detection, distributed fiber optic sensor, PPP-BOTDA, structural fire safety, temperature distribution

Citation

Bao, Y. , Hoehler, M. , Tang, F. , Smith, C. , Bundy, M. and Chen, G. (2017), Temperature measurement and damage detection in concrete beams exposed to fire using PPP-BOTDA based fiber optic sensors Optic Sensors, Smart Materials & Structures, [online], https://doi.org/10.1088/1361-665X/aa89a9, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921117 (Accessed April 26, 2024)