2025 RTP round - Non-contact Non-destructive Condition Assessment of Concrete Bridge Structures.

Status: Open

Applications open: 1/07/2024
Applications close: 20/08/2024

View printable version [.pdf]
About this scholarship
Description/Applicant information

 

Project Overview

Four in Five Australians live within 50 km of the coastline. This population is serviced by a road network of about 14,500 km of National highways and 265,000 km of major local roads. These roads are supported by 53,000 bridges which are predominantly made of Reinforced Concrete (RC). According to the National State of the Asset Report in 2021, a total of $1.2 bn of these RC bridges are in poor and very poor condition. A significant number of these RC bridge structures are built close to the marine environment. In these bridges that are close to the chlorine ions-rich marine environment, the steel in the concrete corrodes. Thus, corrosion spreads like Cancer in Concrete. and it is not visible until an advanced state. Structures are monitored predominantly through visual inspections. These inspections are subjective and time-taking. Regular detailed non-destructive/ semi-destructive inspections are undertaken at best once in 5 years. Detailed inspections are usually undertaken through Electrochemical methods which provide a likelihood of corrosion but not its extent. Other methods like X-Rays and piezo-generated ultrasound have issues in terms of their applicability for on-site applications and establishing reliable contact between the sensor sets and the structure. A reliable non-contact non-destructive monitoring suitable for on-site applications is warranted.

 

Aims

The following aims have been identified for this project:        
A1: Non-contact Non-destructive imaging of concrete Bridge Structures   
A2: Identify the inception of corrosion, track, and image its progress in concrete Bridge Structures.    
A3: Operationalising an imaging system for on-site applications.

 

Objectives

The following objectives will help achieve the aims of this project identified in the earlier section. 
O1: Undertake numerical simulations to establish congenial excitation–reception positionings for Imaging.  
Non-contact Laser generated Ultrasound in concrete has not been extensively explored through numerical simulations. A Multiphysics model coupling Laser generated heat propagation with that of structural dynamics will be used to develop these computer models. These models will be solved using Finite Element Analysis. The dispersion pattern of these ultrasonic waves will be studied and thus a scheme for the optimal placement of reception points will be obtained. Dr. Majhi’s expertise in ultrasonics and Professor Mukherjee’s expertise in numerical simulations will be used in developing computer models. Thus, these numerical simulations will be used to determine the possible locations and reception points on the concrete specimens. 

   
O2: Cast benchmarking concrete bridge specimens for imaging.      
In this project, a series of concrete specimens of up to 3m in length will be cast. Two sets of specimens, one set focusing on the development of ultrasonic imaging and another set focusing on tracking corrosion will be cast. The efficacy of the excitation-reception positioning as determined from the numerical simulations will be validated for these sets. Variations in the depth of bridge decks, the variable diameter of rebars, and their presence in multiple layers will be incorporated into these specimens. Simulated debonding and imperfections in the concrete mix in terms of honeycombing of various degrees would also be incorporated. Thus, a series of interfacial defects in concrete will be created and these specimens will serve as the benchmark for developing Concrete Imaging. These specimens will serve as a rich repository for benchmarking specimens which shall attract researchers from across the globe.     

        
O3: Develop novel Imaging schemes to generate representative images of model concrete bridge specimens.     
Ultrasonic data will be collected on these specimens. And as a result, representative images of them will be generated. The Synthetic Aperture Focusing Technique will be used as the main ultrasonic imaging technique in this project. Professor Mukherjee and Dr. Majhi have expertise in working with this method. However, this technique has not been applied to Laser-based ultrasonics. This imaging technique will be supplemented by methods like Reverse Time Migration and Image Focusing to improve the image contrast. Through these improved images, the changes in interfaces in concrete will be noticed. The ultrasonic images generated on these specimens will be archived and shall serve as reference data for researchers across the globe.     

  
O4: Induce corrosion on model concrete bridge specimen and undertake long-term corrosion studies using Imaging.   
Undertaking accelerated corrosion on large-scale model concrete bridge specimens and their subsequent monitoring has not yet been undertaken and thus will be a novelty. Dr. Majhi and Professor Mukherjee have undertaken long-term corrosion monitoring and have three joint publications in reputed journal articles in this area. In laboratory conditions, corrosion will be induced and accelerated in the embedded rebars using an anodic current. Using this method, a few decades of equivalence of corrosion in field conditions will be induced in a few months under laboratory conditions. Imaging data will be collected at various stages of corrosion on these specimens and further analysed.   

O5: Use Machine Learning to identify and track incipient corrosion in the concrete bridge section.   
As embedded steel bars corrode, there will be a build-up of a rust layer between the rebar and concrete. The developing rust layer would crack concrete around the rebar and cause micro-cracks in concrete around the rebar. Machine Learning will be used to track the propagation of these cracks from the Ultrasonic Imaging. The features from the Ultrasonic Image will be used to train a Convolution Neural Network to identify these cracks and their veracity. This network will also be extended to predict the state of corrosion. Professor Mukherjee’s association with the SmartCrete CRC in developing smart monitoring of concrete assets will be leveraged to develop the feature-based identification system for corrosion classification. 

O6: Develop an Inspection Vehicle capable of remote inspections of long Bridge Structures. 
The technology developed in Laser-based non-contact generation-reception of ultrasound coupled with the novel imaging and Machine-learning based corrosion detection will adapt for field deployment. This field-deployable vehicle will be capable of inspecting concrete bridge sections of a few hundred meters at one stretch. Dr. Majhi’s extensive experience working with Main Roads Western Australia will be used to develop an inspection vehicle suitable for practising engineers.  Curtin University will benefit from the Intellectual Property rights of this vehicle.      
The PhD student will work closely with three honours students and three Master of Professional Engineering (MPE) student who will help them in data acquisition and data curation.

 

Significance 

Inspection of critical civil infrastructure assets like bridge structures is paramount. This helps in setting important landmarks in maintenance intervention. There are about 53,000 bridges in Australia which are predominantly made of Reinforced Concrete (RC). They require regular monitoring. About $1.2 bn of these RC bridges are in poor and very poor condition which will require even more detailed assessment. According to Infrastructure Australia, there is a historic underspending in the monitoring of these bridge structures. Thus, in the upcoming decade, there is a great need to invest in the monitoring of these bridge structures. These bridges are usually inspected visually, making this process subjective. Moreover, Condition Monitoring Engineers regularly need to undertake inspections at difficult-to-access bridge sites to monitor them. This has resulted in Occupational Health and Safety related injuries to the inspectors in many cases.  

The application of accurate monitoring methods like X-Rays and Ultrasonics has been confined to laboratory applications. These technologies are either non-scalable for field applications or have limited power delivery limiting their field implementation. A non-contact non-destructive inspection vehicle capable of inspecting all bridges on-site is thus warranted. Professor Mukherjee and Dr. Majhi have extensively investigated Laser-induced ultrasound and imaging schemes for monitoring civil structures. Laser-generated ultrasound is a few orders of magnitude higher than that of conventional methods. They are capable of monitoring large Bridge structures. Feasibility studies have demonstrated the efficacy of these methods as proofs-of-concept on Laboratory scale specimens. Thus, there is a strong ground to implement these monitoring methods for monitoring Large Bridge structures through an inspection vehicle.

The proposed project will benefit through three pathways, (i) expertise from experienced researchers at the School of Civil and Mechanical Engineering, Curtin University, (ii) State of the Art experimental facilities at the Laser Ultrasonic Laboratory (iii) Computational Facilities for numerical simulations. The expertise and experience of Dr. Majhi and Professor Mukherjee in Civil Engineering Structural condition monitoring will be leveraged for this project. Dr. Majhi has expertise in Piezo and Laser-based instrumentation for condition monitoring of Civil Structures. He has used his expertise in extensively Ultrasonic Signal Processing and Imaging in Concrete long-term concrete corrosion studies. His expertise will be leveraged to develop a condition-monitoring vehicle for concrete bridges. Professor Mukherjee has extensively worked on using computational mechanics in developing a fundamental understanding of wave-based condition monitoring of Civil Structures. He also has expertise in working on multi-modal monitoring methods for long-term condition evaluation of concrete structures. Dr. Majhi and Professor Mukherjee have a total of 13 joint journal article publications and 6 peer-reviewed conference articles. They have worked together on a Category 3 Research project with Main Roads Western Australia on developing a sensor for monitoring Timber Bridges. Thus, the present project will benefit from their proven track history of working together on condition monitoring.   

They will be used to develop novel numerical models to understand wave propagation in concrete structures. The Laser Ultrasonics Laboratory at Curtin University has a High-Power pulsed Laser for excitation and a high-precision Laser Vibrometer for measurement. The excitation Laser is capable of non-contact generation of ultrasonic waves and Vibrometer measures these waves. Thus, the researchers, experimental facilities, and computational facilities at the School of Civil and Mechanical Engineering would be a perfect fit for the project. Benchmarked specimens will be cast. Ultrasonic data will be collected on these specimens. 

Student type

• Future Students

Faculty

• Faculty of Science & Engineering
  • Science courses
  • Engineering courses

Course type

• Higher Degree by Research

Citizenship

• Australian Citizen
• Australian Permanent Resident
• New Zealand Citizen
• Permanent Humanitarian Visa
• International Student

Scholarship base

• Merit Based

Value

The annual scholarship package, covering both stipend and tuition fees, amounts to approximately $70,000 per year.

In 2024, the RTP stipend scholarship offers $35,000 per annum for a duration of up to three years. Exceptional progress and adherence to timelines may qualify students for a six-month completion scholarship.

Selection for these scholarships involves a competitive process, with shortlisted applicants notified of outcomes by November 2024.

Scholarship Details
Maximum number awarded

1

Eligible courses

All applicable HDR courses.

Eligibility criteria

The following skill sets will be desirable in the PhD student.  
Essential: 
• Self-motivated student 
• Demonstrated High-level organisational and communicational skills.  
• Ability to work independently on tasks and work as a group. 
• Undergraduate Honours / master’s degree in civil/ mechanical engineering or physics.   
• Sound understanding of coding in MATLAB/ Python. Operational understanding of working with Numerical Analyses software like ABAQUS/ Ansys or COMSOL.  
Preferable: 
• Research experience in world-class research laboratory. 
• Experience in Operations in an engineering/research organisation.
 

Application process

Please send your CV, academic transcripts and brief rationale why you want to join this research project via the HDR expression of interest form to the project lead researcher, listed below. 

Enrolment Requirements

You must be enrolled in a Higher Degree by Research Course at Curtin University by March 2025.

Enquiries

Project Lead: Professor Abhijit Mukherjee

Scholarships Email Alert
Sign up now