Flexural behaviour evaluation on foamed bitumen stabilised pavement beams using fibre optic sensors

ABSTRACT

The paper aims to evaluate the effectiveness of both distributed fibre optics sensors (DFOs), and fibre Bragg grating sensors (FBGs) to acquire an accurate measurement of the flexural strain of foamed bitumen stabilised (FBS) beams and to assess the material behaviour under both static and dynamic loading conditions. The beams were equipped with DFOs, FBGs and a linear variable differential transformer (LVDT) to perform the static and dynamic flexural tests using a four-point bending apparatus. The initial plastic flexural strain progression of both top and bottom faces of the beam specimen under different test conditions, including different load pulse shapes and rest periods were evaluated. The results revealed that both haversine-upward and haversine-downward pulse shapes lead to a significant amount of plastic flexural strain compared to that evolved through sinusoidal pulse shapes. However, the plastic flexural strain under haversine pulse shapes can be minimised by introducing a rest period at certain cycle intervals. Further, the flexural strain profile captured by DFOs during the static and dynamic flexural tests indicated the capacity of DFOs to detect cracks initiation and propagation.

KEYWORDS:

• Distributed fibre optic sensors
• fibre Bragg grating sensors
• foamed bitumen
• flexural fatigue
• four-point bending
• sinusoidal
• haversine

Acknowledgement

This research work is part of a research project sponsored by the ARC Smart Pavements Hub - SPARC (Project ID: IH180100010, https://sparchub.org.au) and ARC Nanocomm Hub (Project ID: IH150100006) at Department of Civil Eng, Monash University funded by the Australian Research Council (ARC) Industrial Transformation Research Hub (ITRH) Scheme. The financial and in-kind support from the Australian Road Research Board (ARRB) through these ITRH schemes is greatly acknowledged. The authors would also like to thank Pavetest Pvt Ltd and Australian Defence Science and Technology (DST) for their in-kind support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research work is part of a research project (Project No IH18.02.1) sponsored by the SPARC Hub (https://sparchub.org.au) at Department of Civil Eng, Monash University funded by the Australian Research Council (ARC) Industrial Transformation Research Hub (ITRH) Scheme (Project ID: IH180100010).