Yu Bai

• PhD
• Professor at Monash University (Australia)

An adhesively bonded modular GFRP sandwich system for use in building floor construction is described in this paper. Sandwich units are formed by incorporating standard pultruded GFRP box or I-profiles between two GFRP flat panels to form built-up modular sections with considerable improvement of bending stiffness. These modular sections can then b...

Based on temperature-dependent thermo-physical property models developed previously, a one-dimensional model was proposed to predict the thermal responses of FRP composites in time and space domain, up to high temperatures. An implicit finite differential method was used to solve the governing equation. The progressive change in thermo-physical pro...

The complex mechanical modulus of polymer and polymer based composite materials showed a frequency-dependent behaviour during glass transition relaxation, which was historically modelled by the Arrhenius equation. However, this might not be true in a broad frequency domain based on the experience from the frequency dependence of the complex dielect...

The concept of confined concrete has been widely accepted throughout the structural engineering field, such as the spiral, steel tube, or carbon fiber composite shell confined concrete, etc. In the present study, this concept has not only been used in the structural columns, but also in joints. In this connection system, the steel tube is interrupt...

A new connection system for a concrete filled steel tube composite column and reinforced concrete beams is proposed. In this connection, the steel tube is interrupted while the reinforced concrete beams are continuous in the joint zone. Multiple lateral hoops that constitute the stiffening ring are used to confine the core concrete in the connectio...

Graph Neural Networks (GNNs) have emerged as a promising solution for effectively handling non-Euclidean data in construction, including building information models (BIM) and scanned point clouds. However, despite their potential, there is a lack of comprehensive scholarly work providing a holistic understanding of the application of GNNs in the co...

The construction industry is a hazardous industry with significant injuries and fatalities. Few studies have used data-driven analysis to investigate injuries due to construction accidents. This study aims to deploy machine learning (ML) models to predict four injury types (ITs): Upper limbs, lower limbs, head/neck, and back/trunk. A total of 16,87...

Studies have shown that the proper selection of core materials in sandwich structures improves the overall structural performance in terms of bending stiffness and strength. The core materials used in such systems, such as foam, corrugated, and honeycomb, are frequently applied in aerospace engineering. However, they are a costly option for civil e...

Plantation softwood timber poles are associated with low natural durability, and it is also not clear what the effects of the high humidity environment on the long-term performance of composite action integrity of such a system. This paper presents a durability study for the proposed composite poles using (GFRP) glass fiber-reinforced polymer as a...

This chapter numerically investigates the proposed bonded sleeve connection for joining tubular glass fibre reinforced polymer (GFRP) composites and steel members. Experimental results focused on mechanical responses of such specimens using bonded sleeve connections and conventional steel angle connections were introduced in previous chapter. These...

This study investigates the cyclic performance of splice connections developed for hollow section fibre reinforced polymer (FRP) members. Splice connection specimens, each consisting of a steel bolted flange joint between two hollow section steel-FRP bonded sleeve joints, are prepared in three configurations with difference in bolt arrangement or b...

This chapter presents an investigation into the performance of pultruded glass fibre reinforced polymer (GFRP) square hollow columns under eccentric compression, i.e. subjected to both compression and bending. Eccentric compression experiments were performed on slender GFRP column specimens at different eccentricities. Bolted sleeve joint was emplo...

This chapter presents the cyclic performance of bonded sleeve connections for joining tubular glass fibre reinforced polymer (GFRP) beams and columns. Specimens with different endplate thickness and number of bolts are examined under cyclic loading. The hysteretic moment-rotation responses of specimens, including rotational stiffness, ultimate mome...

Multicellular web-flange composite structures were assembled using glass fibre reinforced polymer (GFRP) box sections as web sections and plates as face sheets, further with glass magnesium (GM) or gypsum plaster (GP) panels on the surface for fire protection. The structures were subjected to ISO 834 fire curve from underside where the GM or GP pan...

This chapter presents a modular assembly of sandwich structures using glass fibre reinforced polymer (GFRP) components for two-way slab applications. The sandwich assemblies were built-up sections made from pultruded web-core box (i.e. square hollow section) profiles incorporated between two flat panels, connected via adhesive bonding or novel blin...

The shear stiffness of proposed blind bolts was experimentally investigated in this chapter through steel-FRP joints loaded in tension, for shear connections within the steel-fibre reinforced polymer (FRP) composite beam systems. The number of bolt rows (either one or two bolt rows) and the effect of the pultrusion orientation of the FRP web-flange...

This chapter presents an experimental and modelling investigation into modular composite beam structures using web-flange fibre reinforced polymer (FRP) and steel for building floor construction. The modular FRP slabs are formed from adhesively bonding pultruded box profiles (i.e. square hollow sections) sandwiched between two flat panels. They are...

Web-flange sandwich structures were built up by two glass fibre reinforced polymer (GFRP) panels and square hollow sections (SHS) in between through adhesive bonding or mechanical bolting. Experiments in compression were conducted in order to understand the failure modes including global and local buckling, load-bearing capacities, load–displacemen...

This chapter focuses on the mechanical performance of fibre reinforced polymer (FRP) columns with square hollow sections (SHS) in axial compression. Width-thickness ratio (b/t) is an important geometric parameter for the local buckling of plates and therefore also for such SHS columns. The effects of b/t on the failure modes and load-carrying capac...

A splice connection is introduced in this chapter for connecting tubular fibre reinforced polymer (FRP) members. This connection consists of a steel bolted flange joint (BFJ) and two steel-FRP bonded sleeve joints (BSJs). The BFJ connects two steel hollow sections, each of which is telescoped into the targeted tubular FRP member through adhesive bo...

With the success of applications in aerospace, marine, electrical, automotive transportation industries, fiber reinforced polymer (FRP) composites have also found their places in civil engineering. The use of glass fibers (therefore GFRP) further reduces material costs and incorporates beneficial environmental aspects such as low energy consumption...

Bonded sleeve joints formed by telescoping a steel tube connector for bolt-fastening have been shown as effective means for assembling tubular fibre reinforced polymer (FRP) members into more complex structures such as planar or space frames. A theoretical formulation is developed in this chapter to estimate the capacity of such joints in axial loa...

Timber and steel studs or posts are commonly used in wall constructions for buildings. In this context and with the results from previous chapters, pultruded glass fibre reinforced polymer (GFRP) studs may provide an alternative solution considering their light weight and improved durability. However, integrating the GFRP wall studs to a steel fram...

The flexural behaviour of glass fiber-reinforced polymer (GFRP) composite modular wall systems was evaluated experimentally and analytically. Full-scale wall panels were tested under uniformly distributed and concentrated loads to investigate the effects of wall sheathing, types of connections between sheathing and frame, inter-panel connections, a...

Fibre reinforced polymer (FRP) composites could be an alternative of traditional materials for modular construction due to their superior strength to weight ratio, corrosion resistance and immunity from biological degradation. This paper investigates the in-plane shearing behaviour of full-scale modular wall system made from all glass FRP (GFRP) re...

Using waste rubber tires for concrete production will reduce the demand for natural aggregate and help to reduce environmental pollution. The main challenge of using waste rubber tires in concrete is the deterioration of mechanical properties, due to poor bonding between rubber and cement matrix. This research aims to evaluate the mechanical and th...

This paper presents experimental and numerical investigations of shear performance of one-sided single and multi-row bolted joints. This new type of one-sided bolts achieves one-side installation through elliptical bolt head as well as elliptical bolt hole with varying radius along the perimeter on connected members. Because of such configurations,...

Prediction of wildfire propagation plays a crucial role in reducing the impacts of such events. Various machine learning (ML) approaches, namely Support Vector Regression (SVR), Gaussian Process Regression (GPR), Regression Tree, and Neural Networks (NN), were used to understand their applicability in developing models to predict the rate of spread...

Modular building construction has attracted significant attention from the construction industry in recent years. This type of construction system has been reasonably used in the Sweden, United Kingdom, United States and Japan, whilst becoming popular in Australia, China, Netherlands, Germany and Hong Kong. This chapter presents the benefits of mod...

Applications of photovoltaic (PV) cells in buildings are often excluded from locations with major mechanical strains because of their brittleness and possible damages at small mechanical strains. Combinations of glass fibre reinforced polymer (GFRP) components and amorphous silicon (a-Si) photovoltaic cells show potentials, while the effects from e...

This paper presented an experimental investigation on epoxy mortar produced using industrial wastes, namely coal bottom ash as filler to replace sand, fly ash and silica fume as micro fillers. Four parameters investigated were: (i) the epoxy resin to filler ratio, (ii) particle size of coal bottom ash, (iii) types of micro filler, and (iv) proporti...

Multicellular web-flange composite structures were assembled using glass fibre reinforced polymer (GFRP) square tubes as web sections and plates as face sheets, further with glass magnesium (GM) or gypsum plaster (GP) panels on the surface for fire protection. The structures were subjected to ISO 834 fire curve from underside where the GM or GP pan...

This study investigated the axial behaviour of precast concrete panels with hollow composite reinforcing systems (CRSs). These systems were provided to create voids, reduce the concrete and the self-weight of the panels. Thirteen specimens representing the unit width of a precast concrete panel were prepared and tested under concentric axial compre...

Hollow-core precast concrete slabs are now being used in modular building construction to minimise the volume of concrete and to reduce their weight. However, the existence of voids in hollow-core concrete slabs makes the slab prone to premature failure. Recently, a composite reinforcing systems (CRS) has been developed to support the void in preca...

An innovative beam concept made from hollow FRP tube with external flanges and filled with crumbed rubber concrete was investigated with respect to bending and shear. The performance of the rubberised-concrete-filled specimens was then compared with hollow and normal-concrete-filled tubes. A comparison between flanged and non-flanged hollow and con...

This literature review has examined the use of FRP composite materials as a potential retrofitting technique for civil structures. Importantly, the various material properties, bond mechanisms, durability issues and fatigue resistance have been discussed. Studies exploring the performance of CFRP repaired steel have strongly indicated its potential...

Hollow core concrete-panels are prone to shear failure due to collapse of the voids. In this study, the shear behaviour of hollow precast concrete-composite structures (HPCCSs) reinforced with steel bars and composite reinforcing system (CRS) were investigated. Eleven concrete-panels with different unit-widths (175 mm, 200 mm and 300 mm) and shear-...

The structural behaviour of modular wall systems made from pultruded glass fibre reinforced polymer profile and composite sheathings was evaluated experimentally and numerically. Full-scale wall panels were tested under axial compression to investigate critical design parameters including presence of wall sheathing, connections between sheathing an...

Building-integrated photovoltaics (BIPV) are multifunctional building components using exterior surfaces not subjected to structural loads to generate electricity by solar cells; while a few types of PV cells with higher flexibility have shown potentials to extend the application of BIPV components to load-carrying scenarios. In this paper thin-fil...

Carbon fibre reinforced polymers have shown an ability to provide increased strength and rehabilitation properties to steel. However, under extreme environmental conditions adhered CFRP/steel joints undergo detrimental reductions in strength and durability. This paper explores the use of silane chemical barriers and adhesive modifications to improv...

This paper presents a comparative study on single-bolted double-lap joints with steel bolts and glass fibre reinforced polymer (GFRP) bolt. Three types of steel bolts including plain, galvanised and stainless and a newly developed GFRP bolt were considered. Two preload levels were practiced in the experiments, i.e. snug-tight and full-tensioning. T...

An experimental study was conducted to investigate the cyclic behaviour of an innovative prefabricated connection system for steel beam to concrete-filled steel tube (CFST) column. In this connection system, internal stiffeners and threaded steel rods are used to stiffen the panel zone of the connection, and beams in two directions are bolted to th...

In this study the durability of the bond between different fibre reinforced polymer (FRP) tubes and seawater sea sand concrete (SWSSC) under seawater condition is investigated. Concrete filled pultruded glass fibre reinforced polymer (GFRP) tubes and filament winding GFRP, carbon fibre reinforced polymer (CFRP) and basalt fibre reinforced polymer (...

Modular construction uses prefabricated structures as building modules, transported from the factory to the construction site, for the final assembly. Despite the ongoing interest in modular construction, specific design practices have not been fully developed, particularly with consideration of non-traditional loadings, such as those during transp...

Wind barrier structures on railway bridges are installed to mitigate the wind effects on travelling trains; however, they cause additional wind loads and associated aerodynamic effects on the bridge. An innovative concept was developed for a wind barrier structure in this study that used a glass–fibre–reinforced polymer (GFRP) that may deform prope...

Column-to-column bolted end-plate connections with stiffeners welded on the end plates and column side faces for steel modular buildings were investigated, to understand the effect of stiffener configurations on tensile capacity and stiffness. The connection performance was experimentally examined in tension, focusing on the flexure behaviour respo...

Using fibre reinforced polymer (FRP) composites together with seawater and sea sand concrete (SWSSC) in coastal areas will overcome the environmental issues of using ordinary concrete and corrosion problems of conventional steel reinforcements. The present research investigates the mechanical properties of different SWSSC filled FRP tubes after exp...

Mechanical properties of various GFRP pultruded profiles under SWSSC is investigated. Effect of initial exposure to UV radiation and moisture before subjecting to SWSSC is studied. Samples initially exposed to UV and moisture show higher reductions after exposure to SWSSC. Profiles with interlaminar shear failure are more vulnerable than profiles w...

This article presents an investigation on the durability of different glass-fibre-reinforced polymer composites when subjected to harsh outdoor conditions, including freeze/thaw cycles, ultraviolet radiation and moisture, as well as when used with seawater sea-sand concrete for construction applications. To achieve this, the effects of a number of...

This paper presents an innovative self-floating fibre reinforced polymer (FRP) composite structure for photovoltaic energy harvesting through both experimental and numerical studies. The main structural components include the primary beams using FRP composite tube system and secondary beam using galvanized steel rectangular hollow sections to form...

A framework is developed in this article to predict the nonstationary random ground vibrations induced by high-speed trains, by combining the pseudo-excitation method with the two-and-a-half-dimensional finite element method. This development contains two steps. First, the power spectral density of the wheel-rail dynamic force is accurately obtaine...

Building construction has developed from the use of primitive tools to that of machinery, with a tendency toward automation. Automation of processes and robotics can improve efficiency, accuracy and safety in construction. On the other hand, structural prefabrication for construction is increasingly being adopted worldwide to enhance productivity a...

This study investigates the cyclic performance of splice connections developed for hollow section fibre reinforced polymer (FRP) members. Splice connection specimens, each consisting of a steel bolted flange joint between two hollow section steel-FRP bonded sleeve joints, are prepared in three configurations with difference in bolt arrangement or b...

Hardwood as sourcing of utility poles becomes difficult and costly due to its slow replenishment and the high clearing rates in the 19th century as well as occasional bushfires. There is a critical need to source other timber species for timber poles. This paper presents a study of using fibre reinforced polymer (FRP) composites as a confinement sy...

Modular construction uses panelised and volumetric units that are manufactured and furnished in a factory and delivered for site assembly. Such units are often transported on trucks through different road conditions and damages have been identified after transportation in practices. As a result, the evaluation of acceleration responses becomes impo...

h i g h l i g h t s Pultruded GFRP tubes in seawater sea sand concrete and seawater environments. Tests to obtain mechanical properties of GFRP tubes after conditioning. Study of microstructural properties, degradation mechanisms and damage levels. A reduction factor was recommended to consider influence of exposure on strength. a b s t r a c t Thi...

Ductile performance of beam structures often is achieved by material yielding or progressive failure of components. A new structural concept was developed and validated in this study to provide ductile responses of beam structures through load-dependent composite action resulting from the change in the modulus of shear connection. Layered beam spec...

Resource shortage of fresh water and river sand due to the widespread increase of industrialization and urbanization can be reduced by using seawater and sea sand concrete (SWSSC), which has recently been proposed as an alternative to conventional ordinary Portland cement (OPC)-based concrete. Due to the high rate corrosion of traditional carbon st...

Concrete-filled FRP tubes, in which a great strength and stiffness will be provided in the case of using appropriate fibre orientations may be used as structural members, such bridge piers. Moreover, using sea water and sea sand concrete (SWSSC) is recently proposed to reduce the resource shortage of fresh water and river sand and address the envir...

Concrete-filled FRP tubes, in which a great strength and stiffness will be provided in the case of using appropriate fibre orientations may be used as structural members, such bridge piers. Moreover, using sea water and sea sand concrete (SWSSC) is recently proposed to reduce the resource shortage of fresh water and river sand and address the envir...

Resource shortage of fresh water and river sand due to the widespread increase of industrialization and urbanization can be reduced by using seawater and sea sand concrete (SWSSC), which has recently been proposed as an alternative to conventional ordinary Portland cement (OPC)-based concrete. Due to the high rate corrosion of traditional carbon st...

An efficient hybrid method (HM) is proposed by combining the direct stiffness method (DSM) and the mode superposition method (MSM) for analyzing the train-track-bridge coupled system (TTBS). The train and the track are modeled by applying the multi-body dynamics and the DSM, respectively. The bridge is modeled by applying the MSM that is efficient...

The present research examines the effects of UV radiation, moisture and elevated temperature on the mechanical properties of GFRP pultruded profiles. Flexural, compressive and tensile properties of different GFRP sections were studied after they were exposed for 1000, 1500, 2000 and 3000 h to UV radiation and water vapour condensation cycles. Mecha...

The present study indicates the importance of using glass fiber reinforced polymer (GFRP) laminates with appropriate thickness and fibers orientation when exposed to harsh environmental conditions. The effect of different environmental conditions on tensile properties of different GFRP laminates is investigated. Laminates were exposed to three envi...

This paper presents experimental and numerical investigations of the bending performance of innovative splice connections developed for tubular section FRP members. Each of the splice connections consists of a steel bolted flange joint between two tubular steel-FRP bonded sleeve joints. Three connection specimens with different bolt configurations...

In the present study the bond-slip behavior between FRP tubes and seawater sea sand concrete is studied using push-out tests. Pultruded and filament winding FRP tubes with different fibre orientations and diameter-to-thickness ratios (D/t) were constructed to investigate the effect of confinement pressure on the bond behaviour. Moreover, to study t...

In the present study the bond-slip behavior between FRP tubes and seawater sea sand concrete is studied using push-out tests. Pultruded and filament winding FRP tubes with different fibre orientations and diameter-to-thickness ratios (D/t) were constructed to investigate the effect of confinement pressure on the bond behaviour. Moreover, to study t...

This paper investigated the structural robustness of steel-framed modular buildings based on the alternative load path method using LS-DYNA. The structural responses of a reference structure were first simulated to understand typical building motion, load redistribution mechanisms and failure modes after removal of a base corner module. Based on th...

In this paper, an efficient and robust approach is presented for the prediction of subway train-induced ground vibrations considering random track unevenness. The proposed approach is developed by a two-step approach. Firstly, the power spectral density functions of the wheel–rail interaction forces are obtained through the combination of the vehic...

Building integration using thin-film flexible photovoltaic (PV) cells with load-carrying structures requires understanding of their electrical performance under continuous mechanical loadings. Limited results mainly focus on the electrical performance of PV cells under certain fixed mechanical strains. In this paper, an approach is examined to cont...

An innovative nodal joint system with thin-walled steel sleeve and plate is examined for development of latticed shell structures using hollow section glass fiber reinforced polymer (GFRP) members. In the proposed system, the GFRP members were connected to a steel gusset-plate space node through bolted sleeve joints (BSJs). The mechanical performan...

This paper investigates the mechanical performance of beam-to-column connections for steel-framed building modules with RHS and SHS sections of relatively small member sizes. In the experimental program, three forms of connections are tested under static bending, including a completely welded connection (W), a bolted end plate connection (EP) and t...

An innovative pultruded fiber reinforced polymer (FRP)–wood composite (PFWC) column with a lightweight southern pine wood core confined by outer FRP sheets was manufactured using an improved pultrusion process. Axial compression tests with both ends pinned as boundary conditions were employed to investigate the mechanical performance of such PFWC c...

Modular construction offers faster and safer manufacturing, better predictability to completion time, superior quality, less workers on site, less resource wastage, and a more environmentally friendly solution than the conventional construction process. Despite having several advantages of modular construction, the private sector still relies heavi...

This paper extends the 2D multi-time-step (MTS) method previously proposed by the authors to 3D train-track-bridge dynamic analysis for evaluating in detail the running safety and riding comfort of a train. The train-track-bridge coupled system (TTBS) is separated into the train subsystem, the track subsystem, and the bridge subsystem. These subsys...

This paper presents the experimental and analytical studies of double-chorded composite truss system connected using stainless steel through-bolts with mechanical inserts. The composite trusses were assembled using rectangular hollow sections of pultruded glass fibre reinforced polymer (GFRP) where adhesively bonded mechanical inserts were introduc...

This paper presents an investigation into the performance of pultruded glass fibre reinforced polymer (GFRP) square hollow columns subjected to both compression and bending. Eccentric compression experiments were performed on slender GFRP column specimens at different eccentricities. Bolted sleeve joint was employed to connect the GFRP column speci...

Fibre reinforced polymer (FRP) composites have become known for their specific advantages for civil infrastructure construction. High corrosion resistance in particular is one such strength, which has led to successful applications worldwide. This paper focuses on the structural applications of FRP composites as major load-carrying members (therefo...

Width–thickness ratio is an important geometric parameter in the local buckling of plates and, therefore, also for columns with square hollow sections (SHS). This paper reports on an investigation into the effects of width–thickness ratio (b/t) on the failure modes and load-carrying capacities of SHS columns made from pultruded glass fibre reinforc...

A bonded sleeve connection was developed for joining tubular glass fiber-reinforced polymer (GFRP) beams and columns. It utilizes a sleeve connector made by welding a steel tube to a steel endplate. The steel tube is then inserted into and adhesively bonded with the GFRP beam end and the endplate is connected to the GFRP column using through-bolts....

A retaining wall system modularly assembled from pultruded glass fibre reinforced polymer (GFRP) sections filled with concrete is introduced in this paper. Two main components (i.e., plank and pile) of the modular system are investigated experimentally at different spans under four-point bending to understand different failure modes. The effect of...

Pultruded fibre reinforced polymer (FRP) members are increasingly favoured in civil engineering as they are lightweight and corrosion-resistant. However, their application is limited by the challenge to connect them, especially tubular members, i.e. with closed sections. A splice connection is developed in this paper for tubular FRP members and its...

The bending behavior of an innovative fiber reinforced polymer (FRP) sandwich panel was investigated for application in a multistory building. The panels featured a paulownia wood core reinforced by glass fiber reinforced polymer (GFRP) facesheets and web and was manufactured by a vacuum assisted resin infusion process. Specimens with different web...

This paper presents an experimental and theoretical study of CFRP-confined concrete-filled circular steel tube (CFT) stub columns, which aims at investigating the effects of different numbers of CFRP layers and concrete strengths on the mechanical performance of CFRP-confined CFT stub columns. Based on continuum mechanics, a mechanical model of con...

This study proposes and examines a new structural retaining wall system using pultruded glass fibre reinforced polymer (GFRP) composites. The flexural behaviour of the two section types (double-H-planks and round-piles) are investigated at various spans under four-point bending. The effects of shear span-to-depth (a/d) ratio and sectional geometry...

A splice connection is proposed for connecting tubular fibre reinforced polymer (FRP) members. This connection consists of a steel bolted flange joint (BFJ) and two steel-FRP bonded sleeve joints (BSJs). The BFJ connects two steel hollow sections, each of which is telescoped into the targeted tubular FRP member through adhesive bond, forming a BSJ....