Liam J Butler

• BASc (Waterloo), PhD (Waterloo), PEng.
• Professor (Assistant) at York University

In this paper, distributed fiber optic sensing (DFOS) was used to monitor indicators of track buckling, i.e., the axial strain, curvature, and lateral deflection along a 20-m section of curved track during the summer when ambient temperatures are highest. The objectives of the research were to (i) evaluate the performance of DFOS for this type of m...

The monitoring of infrastructure assets using sensor networks is becoming increasingly prevalent. A digital twin in the form of a finite element (FE) model, as commonly used in design and construction, can help make sense of the copious amount of collected sensor data. This paper demonstrates the application of the statistical finite element method...

Permeable pavements are a type of Low Impact Development technology that aim to reduce stormwater runoff at the source through infiltration and storage. Overtime, sediments carried by stormwater runoff degrade the performance of these pavements and can eventually completely diminish the infiltration capacity of the pavement system. Maintenance proc...

One of the key strategic decisions in bridge infrastructure management is in determining how much additional live load can be allowed on existing bridges. In particular, how to optimise asset utilisation while ensuring structural safety and performance at the same time? This also has significant implications in minimising new build and reducing car...

Distributed fiber optic sensors (DFOS) were used, for the first time, to monitor lateral buckling of a rail under axial loading with different boundary conditions. In the experiments, two types of DFOS systems were used to collect the distributed strain data, and the performance of the two systems was compared. The distributed strain data were used...

This paper reports on the proof-of-concept development of an integrated sensing and strengthening system for reinforced concrete structures. Much of our global concrete infrastructure is in urgent need of repair and/or strengthening interventions to ensure it remains fit-for-purpose. As the use of strengthening systems involving fibre reinforced co...

Multi-girder prestressed concrete bridges are a very common structural form for bridges around the world. Their continued use is expected in the future given the advantages these structures have with respect to speed of construction, reduced maintenance and improved material efficiency. However, the in-service behaviour of these types of structures...

Multi-girder prestressed concrete bridges account for a large proportion of existing bridge stock around the world. Therefore, it is important to ensure that these bridge assets are properly maintained and efficiently utilised. One common question raised by many bridge owners and operators is "How much additional traffic load can be safely placed o...

The monitoring of infrastructure assets using sensor networks is becoming increasingly prevalent. A digital twin in the form of a finite element model, as used in design and construction, can help in making sense of the copious amount of collected sensor data. This study demonstrates the application of the statistical finite element method (statFEM...

There has been a vision of creating bridge digital twins as virtual simulation models of bridge assets to facilitate remote management. Bridge model updating is one digital twin technology which can enable the continuous updating of the structural model as new monitoring data is collected. This paper examines why there is currently little industry...

p>Model updating aims to update an analysis model (e.g. a finite element model) of an engineering structure in order to closely represent the true condition and performance of the physical structure. Model updating of bridges has been an active research field for more than two decades, yet the confidence and practical usefulness of bridge model upd...

This paper evaluates the data collected during a comprehensive monitoring campaign aimed at capturing the prestress loss behaviour of four 11.9 m prestressed concrete beams. These beams formed part of the superstructure of a newly-constructed railway bridge in Staffordshire, U.K. Two types of prestressed concrete beams were monitored, two TY7 inter...

Bridges are critical infrastructure systems connecting different regions and providing widespread social and economic benefits. It is therefore essential that they are designed, constructed and maintained properly to adapt to changing conditions of use and climate-driven events. With the rapid development in capability of collecting bridge monitori...

The implementation of Eurocode 2 (EC2) for the design of concrete structures in South Africa in the near future is pending and necessitates a refined understanding of EC2’s prediction models; including prestress losses and the validity of these estimates for local materials and environmental conditions. In this study, the EC2 prediction model for p...

At the heart of structural engineering research is the use of data obtained from physical structures such as bridges, viaducts and buildings. These data can represent how the structure responds to various stimuli over time when in operation. Many models have been proposed in literature to represent such data, such as linear statistical models. Base...

Prestressed concrete sleepers with built-in fibre optic–based sensing systems have recently been developed to capture performance data within railway networks and to provide critical decision-support information to route managers and operators. To better understand how self-sensing sleepers can be fully utilized within the rail network, a study of...

Half-through steel plate girder bridges are widely used across the United Kingdom's railway network. However, few studies have investigated their real in-service behavior. Concurrently, the use of advanced sensor systems, such as those utilizing fiber-optic sensors, have begun to find widespread use in structural health monitoring due to their high...

A recent development which is poised to disrupt current structural engineering practice is the use of data obtained from physical structures such as bridges, viaducts and buildings. These data can represent how the structure responds to various stimuli over time when in operation, providing engineers with a unique insight into how their designs are...

Prestress losses in precast concrete beams include the short-term effects of elastic shortening and the long-term effects of concrete shrinkage, concrete creep and steel relaxation. Temperature effects are, however, excluded. The aim of this research was to monitor the behaviour of a prestressed precast concrete bridge beam, focussing on temperatur...

This study shows how integrating fiber optic sensor (FOS) networks into bridges during the construction stage can be used to quantify preservice performance. Details of the installation of a large FOS network on a new steel–concrete composite railway bridge in the United Kingdom are presented. An overview of the FOS technology, installation techniq...

This study demonstrates how integrating fibre optic sensor (FOS) networks into bridges during their construction can be used to quantify their pre-service performance. Details of the installation of a large FOS network on a new steel-concrete composite railway bridge are presented. An overview of the FOS technology, installation techniques, and mon...

Instrumentation of infrastructure is changing the way engineers design, construct, monitor and maintain structures such as roads, bridges and underground structures. Data gathered from these instruments have changed the hands-on assessment of infrastructure behaviour to include data processing and statistical analysis procedures. Engineers wish to...

Structural health monitoring data has not been fully leveraged to support asset management due to a lack of effective integration with other data sets. A building information modeling (BIM) approach is presented to leverage structural monitoring data in a dynamic manner. The approach allows for the automatic generation of parametric BIM models of s...

Instrumentation of infrastructure is changing the way engineers design, construct, monitor and maintain structures such as roads, bridges and underground structures. Data gathered from these instruments have changed the hands-on assessment of infrastructure behaviour to include data processing and statistical analysis procedures. Engineers wish to...

Structural health monitoring data has not been fully leveraged to support asset management due to a lack of effective integration with other datasets. A Building Information Modelling (BIM) approach is presented to leverage structural monitoring data in a dynamic manner. The approach allows for the automatic generation of parametric BIM models of s...

Statistical techniques play a large role in the structural health monitoring of instrumented infrastructure, such as a railway bridge constructed with an integrated network of fibre optic sensors. One possible way to reason about the structural health of such a railway bridge, is to model the time it takes to recover to a no-load (baseline) state a...

We explore the role of statistics for Big Data analysis arising from the emerging field of Data-Centric Engineering. Using examples related to sensor-instrumented bridges, we highlight a number of issues and challenges. These are broadly categorised as relating to uncertainty, latent-structure modelling, and the synthesis of statistical models and...

In addition to the traditional benefits associated with the installation of structural health monitoring systems, reductions in construction, operational and maintenance costs, and improved performance and quality can be achieved by effectively using the acquired data. However, considered in isolation, the raw data are of little use and value. They...

This study investigates integrating fibre optic sensing technology into the production process of concrete railway sleepers. Robust fibre Bragg grating strain and temperature sensor arrays were developed specifically for this application and were designed for long-term monitoring of sleeper performance. The sensors were used to monitor sleeper prod...

This study investigates integrating fibre optic sensing technology into the production process of concrete railway sleepers. Robust fibre Bragg grating strain and temperature sensor arrays were developed specifically for this application and were designed for long-term monitoring of sleeper performance. The sensors were used to monitor sleeper prod...

In addition to the traditional benefits that are associated with the installation of structural health monitoring systems, reductions in construction, operational, and maintenance costs and improved performance and quality can be achieved by effectively using the acquired data. However, considered in isolation, the raw data is of little use and val...

This paper evaluates the results of a monitoring study that captures the early age behaviour of four 11.9 m prestressed concrete bridge beams utilising both distributed and discrete fibre optic sensor (FOS) arrays. The performance of the beams is evaluated before they are placed in-service as part of new concrete railway bridges in the Midlands in...

This paper evaluates the results of a monitoring study that captures the early age behaviour of four 11.9 m prestressed concrete bridge beams utilising both distributed and discrete fibre optic sensor (FOS) arrays. The performance of the beams is evaluated before they are placed in-service as part of new concrete railway bridges in the Midlands in...

p>Long-term asset management and maintenance of civil infrastructure relies on having access to reliable performance data in order to inform critical decision-making processes. This paper discusses the development and implementation of a robust, innovative and highly distributed fibre-optic sensor network for use as a bridge monitoring and performa...

Prestressed precast TY beams were monitored for strain and temperature using two embedded fibre optic monitoring technologies, allowing for both distributed static measurements using Brillouin optical time domain reflectometry and dynamic measurements at discrete locations using fibre Bragg gratings at 1 m spacing. The prestressed beams were monito...

Strain data collected during the manufacture of a prestressed concrete TY beam, BM2, for a single span rail-over-water bridge, UB11. The data was collected from 22/01/2015 - 29/01/2015 at Explore Manufacturing, Worksop, UK. The data was collected for the ME01 project being carried out in the Department of Engineering at the University of Cambridge....

The authors thank the discussers for their interest in the journal article and thank them for their comments and contribution towards understanding the structural behavior of concrete incorporating recycled concrete aggregates (RCAs). The discussion has provided several comments and posed questions in regards to the bond testing methods and statist...

This study provides an in-depth evaluation of how fundamental aggregate properties affect mechanical properties of structural concretes produced using 100% coarse Recycled concrete aggregate (RCA) and constant mixture proportions. The key findings presented within this study will assist in developing a framework for classifying RCA sources for use...

This paper presents guidelines for using recycled-concrete aggregate (RCA) as a full or partial replacement for natural coarse aggregate in new concrete (RCA concrete). Several international standards and guidelines for the use of RCA in concrete are reviewed and contrasted to identify areas in which further development is required. The main result...

This study evaluated the effect of fully replacing natural aggregate (NA) with several sources of recycled concrete aggregate (RCA) on the various mechanical properties of multiple concrete mixtures having equivalent compressive strength and slump (compressive strengths between 40 and 60 MPa and slumps between 75 and 125 mm). The RCA concrete (havi...

Using recycled concrete aggregates (RCAs) as coarse aggregate in concrete has the potential to supplement current natural aggregate reserves, divert construction and demolition debris from landfills, and promote the adoption of sustainable civil infrastructure. As many of the design equations used to calculate structural concrete properties are bas...

This study focuses on characterizing several recycled concrete aggregate (RCA) sources, developing concrete mixture proportions that incorporate RCA as coarse aggregate, and investigating the effect of coarse aggregate properties on the main mixture proportion parameters [i.e., cement content, water demand, and water-cement (w/c) ratio]. Four aggre...

The purpose of this study was to investigate the influence that replacing natural coarse aggregate with recycled concrete aggregate (RCA) has on concrete bond strength with reinforcing steel. Two sources of RCA were used along with one natural aggregate source. Numerous aggregate properties were measured for all aggregate sources. Two types of conc...