Allan Manalo

• University of Southern Queensland

Strengthening and rehabilitation of square hollow sections (SHS) is a major concern nowadays as SHS may fail due to higher service loads, fabrication and construction errors, degradation of material over time and adverse effects of the cyclic loading due to earthquakes. In the present study, a detailed experimental investigation has been carried ou...

Pipe-in-pipe (PIP) has become an acceptable system for the rehabilitation and repair of natural gas distribution networks. Damaged host pipes usually contain defects such as circumferential cracks which can affect the performance of the PIP systems. Under internal pressure, the PIP system will be in contact with the damaged pipes and may have an ad...

Aging natural gas pipeline infrastructure needs rehabilitation, and trenchless, pipe-in-pipe (PIP) technologies offer a versatile solution. For example, legacy cast/wrought iron pipes have been subject to elevated incident rates for decades (www.phmsa.dot.gov). In an effort to accelerate innovation, the United States (U.S.) Department of Energy (DO...

The harsh Australian environment makes the use of steel reinforcement in concrete structures problematic on account of corrosion. The probability of corrosion damage will significantly increase in the years to come and will become a major problem not only in coastal regions but also in inland parts of Australia due to increasing carbon dioxide conc...

Glass-fiber-reinforced-polymer (GFRP) bars are an ideal solution for eliminating the problems of steel corrosion in reinforced-concrete structures exposed to marine environments. The potential long-term benefits of the reduced maintenance costs and increased service life of GFRP-reinforced concrete structures have not been fully realized due to the...

When used as an internal reinforcement, fiber-reinforced-polymer (FRP) composite bars are exposed to a highly alkaline (pH > 12.5) concrete environment. This study evaluated the durability of 24 types of FRP bars in a simulated alkaline concrete environment, specifically with respect to reinforcing-fiber type (carbon, basalt, and glass), fiber sizi...

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Plantation softwood is the future timber material resource for building and construction. However, significant volumes of sawn softwood are considered out-of-grade and sold at a loss. New approaches and methods need to be implemented to value-add out-of-grade timber and increase structural yield from existing plantations. This paper provides a crit...

Jacketing using prefabricated fiber reinforced polymer (FRP) composite shells is an attractive repair system for deteriorating structures exposed to the marine environment. However, most available techniques lack an effective joining system capable of providing structural continuity along the hoop direction. This paper addresses the evaluation of t...

This paper presents the flexural behavior of geopolymer-concrete beams longitudinally reinforced with a hybrid of glass-fiber-reinforced-polymer (GFRP) and steel bars. Seven geopolymer-concrete beams with different ratios and configurations of GFRP-to-steel reinforcement were designed, cast, and tested up to failure using the four-point static bend...

This study explored the use glass-fiber-reinforced-polymer (GFRP) bars and spirals as reinforcing materials in hollow concrete columns in order to mitigate steel-related corrosion problems and understand the fundamental behavior of such construction system under the applied loads. Four concrete columns 250 mm in external diameter and reinforced lon...

Val-Alain Bridge on Highway 20 East is the first bridge in Canada in which the concrete deck and barrier walls were fully reinforced with vinyl-ester-based glass-fiber-reinforced polymer (GFRP) bars. Built in 2004, this bridge was considered as the prototype for bridges built thereafter by the Québec Ministry of Transport (MTQ). In 2015, concrete c...

Mixing crude oil contaminated sand with cement and using this mix as an alternative construction material is considered an innovative and cost-effective approach to reduce its negative environmental impact. In this study, the compressive and splitting tensile strength of concrete with different levels of light crude oil contamination (0, 1, 2, 6, 1...

This paper investigated the effect of ceram powder on the properties of composite laminates based on glass fibres and phenolic resin. The amount of ceram in the polymer matrix was varied between 30% and 50% of the weight of resin. The density, void ratio, tensile strength, interlaminar shear strength, bond strength, bending modulus and glass transi...

A new type of composite beam, referred to as Layered Sandwich Beam (LSB) is introduced in this study. The sandwich system consists of Glass Fiber Reinforced Polymer (GFRP) skins and Phenolic cores, and several layers of sandwich panels are bonded together with epoxy polymer matrix for manufacturing beams. To explore the suitability of this novel co...

Prefabricated fibre-reinforced polymer (FRP) composite jacket is now becoming an effective repair system for deteriorating piles and columns exposed to marine environment. This system works by providing grout infills between the annulus of the existing structure and the composite jacket. Few studies are however available on the optimal grouting mat...

Cure ratio is a key property for the acceptance and use of glass fiber reinforced polymer bars in civil engineering infrastructure. Yet, there have been no reported studies investigating the effect of cure ratio on the physical, thermal, and mechanical properties of the fiber reinforced polymer bars. This paper presents an interlaboratory test prog...

This paper introduces an innovative composite railway sleeper with an optimal material usage for a narrow-gauge railway track under static loading condition. The composite sleeper is designed using sandwich panels that were bonded and coated with epoxy polymer matrix. The sleeper’s optimized shape was obtained using topology optimization. The verti...

Fly ash and oil contaminated sand are considered as the two waste materials that may affect environment. This paper investigated the suitability of producing geopolymer cement mortar using oil contaminated sand. A comparison between physical and mechanical properties of mortar produced using geopolymer and Ordinary Portland Cement (OPC), in terms of...

This paper presents experimental investigation, statistical analysis, and theoretical predictions of tensile-strength retention of glass fiber-reinforced polymer bars, made with vinyl-ester, polyester, or epoxy resins. The durability of glass fiber-reinforced polymer bars was evaluated as a function of time of immersion in alkaline solution. The ag...

This paper investigated the shear behaviour of geopolymer-concrete beams reinforced with continuous glass-fibre-reinforced polymer (GFRP) composite spirals. Eight large-scale beams were designed, cast, and tested up to failure to evaluate the effects of the spiral pitch, web-reinforcement configuration, shear-span-to-effective-depth ratio, and long...

Current standards do not consider the diameter of glass fiber-reinforced polymer (GFRP) bars used as internal reinforcement in concrete structures to be a factor influencing bar durability. This paper investigates the effects of bar diameter on the physical and mechanical properties as well as the durability of GFRP reinforcing bars conditioned for...

The standards ASTM D7205/D7205M-06 and CSA S806 contain the commonly used test methods for characterizing the tensile properties of glass fiber-reinforced polymer (GFRP) bars for use as reinforcement in concrete structures. These standards, however, use different anchor dimensions and loading rates, thereby possibly yielding different properties fo...

Fibre composite guardrails are increasingly being used due to its high strength, high corrosion resistance and low maintenance, although there is very limited information on their structural behaviour. In this study, full-scale pultruded glass fibre reinforced polymer guardrail is experimentally investigated to have a better understanding on the be...

Structural sandwich panels made of glass fibre reinforced polymer (GFRP) and a phenolic core are used to manufacture a new type of composite railway sleeper. As these sandwich panels are produced in limited thicknesses for production efficiency, they are bonded together by an epoxy-based polymer matrix with structural filler to manufacture the comp...

This study thoroughly investigated the flexural behaviour of phenolic cored sandwich beams with glass fibre composite skins in the horizontal and vertical positions. The beams have a shear span-to-depth ratio (a/d) varying between 0.5 and 12, and tested under 4-point static bending. Their failure load are then predicted theoretically. The results s...

This paper presents an experimental and theoretical studies of the durability of composite materials made from mixed plastic solid waste (PSW) containing high-density polyethylene, low-density polyethylene, polypropylene and short glass fibres (10–30% by weight). The effects of exposure to elevated temperatures, UV radiation and moisture ingression...

A comparative study was conducted to evaluate the temperature-sensitive mechanical properties of glass fibre reinforced polymer (GFRP) composites in the longitudinal and transverse directions. GFRP coupons with different shear span-to-depth ratios were tested under three-point static bending test at temperatures ranging from room temperature up to...

Oil contaminated sand resulting from oil leakage has continuously been a major environmental concern worldwide. This problem affects the physical and chemical properties of the surrounding soil. Due to prohibitive cost of the existing remediation methods for oil contaminated sand, mixing them with cement and using in construction is considered as a...

Composite beams consisting of pultruded glass fibre-reinforced polymer (GFRP) I-beams and ultra-high-strength fibre-reinforced concrete (UFC) slabs have been developed for use in short-span bridges. Fibre-reinforced polymer bolts (fibre-reinforced polymer threaded rods) and epoxy adhesive were used to connect the UFC slab to the GFRP I-beam. The au...

The lack of knowledge of the behaviour of an epoxy polymer matrix has become a challenging issue for the design of a serviceable, durable and economic matrix. This study investigated the effect of the resin-to-filler ratio on the thermal, physical, mechanical and durability properties of polymer matrices composed with epoxy resin and light weight f...

This research introduces multi-celled glass fibre reinforced polymer (GFRP) beam sections partially filled with concrete. Hollow pultruded GFRP square tubes (125 mm x125 mm x 6.5 mm) were bonded together using epoxy adhesives to form the beams using 2 to 4 cells. Concrete with 15 and 32 MPa compressive strengths was used to fill the top cell of the...

Using oil contaminated sand in engineering applications is considered a clever method in reducing its impact to the environment. In this study, the compressive strength and porosity of cement mortar with 0%, 1% and 10% of light crude oil contamination was evaluated at 28 days of hydration. Results showed that the hydration process was significantly...

This paper presents the results of a collaborative research project between Quebec's Ministry of Transportation and Ontario's Ministry of Transportation, which aimed at characterizing a new type of headed glass fiber-reinforced polymer (GFRP) reinforcing bar and evaluating its suitability as internal reinforcement for concrete structures. To achiev...

Fiber-reinforced composites are a well-recognized option for repair and rehabilitation of the pipelines for the oil and gas industry. Infilled composite sleeve system provides an effective rehabilitation solution, where the sleeve acts as prime reinforcement without any direct contact with steel. However, the long-term performance of the repair is...

Fiber reinforced polymer (FRP) sandwich systems as primary load-bearing elements are relatively new concepts in lightweight civil infrastructure. These systems offer a combination of light weight, high strength, thermal insulation for some types, and service-life benefits. Recent developments and applications have demonstrated that these composite...

Offshore oil and gas pipelines are susceptible to corrosion and need rehabilitation to keep them operating in-service conditions. Fibre composite filled with epoxy-based grout is emerging as an effective repair and rehabilitation system for offshore pipelines performing underwater. In such applications, the infill grout is often subjected to moistu...

The behavior of concentrically loaded geopolymer-concrete circular columns reinforced longitudinally and transversely with glass–fiber-reinforced-polymer (GFRP) bars was investigated. Six full-scale short columns (L/r = 8) were cast: one column without transverse reinforcement; three columns with circular hoops spaced at 50 mm, 100 mm, and 200 mm o...

Recycled mixed post-consumer and post-industrial plastic wastes consisting of HDPE, LDPE and PP were injection moulded with short glass fibre (10–30% by weight) to produce a new generation composite materials. Intensive experimental studies were then performed to characterise the tensile, compression and flexural properties of glass fibre reinforce...

This paper presents the effects of elevated in-service temperature on the flexural behavior of sandwich composites consisting of glass-fiber-reinforced-polymer (GFRP) skins and a phenolic core. The glass transition temperatures of the GFRP skin and phenolic core were obtained from dynamic mechanical analysis (DMA). Subsequently, the flexural behavi...

This paper presents experimental and analytical studies on the effect of the compressive strength of the concrete infill on the flexural behaviour of composite beams. Hollow pultruded Glass Fibre Reinforced Polymer (GFRP) square beams (125 mm x125 mm x 6.5 mm) filled with concrete having 10, 37 and 43.5 MPa compressive strength were tested under st...

The application of fibre-reinforced polymer (FRP) composites for strengthening and rehabilitation of structural elements has become essential in recent years. However, most of the research and developments focused on using FRP strips or plates, which are limited in strengthening metallic structures with flat steel surfaces. In most cases, the damag...

Oil leakage is considered as one of the significant environmental issue worldwide, which affects the physical and chemical properties of the surrounding sand. A range of remediation methods for oil-contaminated sand was recommended but none are considered to be cost effective especially in developing countries. In order to find an alternative and c...

The shear behavior of geopolymer concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars and stirrups was investigated. Six short beams with a shear-span-to-effective-depth ratio (a/d) of 1.8 were cast: one with no stirrups, three with different stirrup spacing, one with less reinforcement, and one with steel stirrups. In addition...

Steel pipelines play an important role in the oil and gas industry. Hence, corrosion of the steel pipe systems during its service life is a critical issue for the industry. Fibre-reinforced composites offer solutions with broad applicability and efficiency for the internal repair of these corroded pipelines. Understanding the behaviour of internal...

This chapter explores an internal FRP repair system for corroded pipelines. A review of internal corrosion defects, internal composite repair technologies, installation methods, advantages and disadvantages is presented. Subsequently, the performance of the available composite technologies for internal repair is evaluated in terms of their maximum...

This study presents a comparison of the shear behaviour of geopolymer concrete beams transversely reinforced with glass fiber-reinforced polymer (GFRP) and steel bars. Two full-scale beams with GFRP and steel stirrups spaced at 150 mm on-center were fabricated and tested up to failure using the four-point static bending test. Another beam without w...

The use of structural pultruded fibre reinforced polymers (FRP) sections have gained wide acceptance in civil engineering applications due to their favourable structural characteristics like high strength, light weight and durability in severe environmental conditions. However, due to their relatively low modulus of elasticity and thinned walls, th...

Elastic properties of the fiber reinforced polymer (FRP) composite represent a significant effect on the structural behaviour of this material. Therefore, it is important to use an accurate method to determine these properties as the behaviour is often governed by deflection rather than strength. In this study, full size pultruded glass FRP (GFRP)...

The popularity of fibre reinforced polymer (FRP) grating is slowly gaining momentum as they offer numerous advantages over customary materials for use in platforms and walkways, particularly within harsh and corrosive environments. However, there are still no detailed guidelines relating to the design and use of FRP gratings, making this material a...

Fibre composite guardrails are increasingly being used to ensure safety of workers from fall-from-height incidents due to its high strength, high corrosion resistance and low maintenance. In this study, the structural behaviour of pultruded glass fibre-reinforced polymer (GFRP) guardrail was evaluated following AS1657-1992. GFRP guardrail systems m...

The geopolymer concrete internally reinforced with fibre-reinforced polymer (FRP) bars is anticipated to offer durable, sustainable, and cost-effective civil infrastructures. In this study, the effect of the anchor head on the pullout behaviour of the sand coated glass-fibre-reinforced polymer (GFRP) bars embedded in the geopolymer concrete was inv...

It is important to determine accurately the elastic properties of fibre-reinforced polymer composites material, considering that their member design is often governed by deflection rather than strength. In this study, the elastic properties of the pultruded glass fibre-reinforced polymer square sections were evaluated firstly using full-scale with...

To understand the contribution of bamboo fibers in a composite system, the characteristics of the fiber should be comprehensively evaluated. One of the major issues regarding the use of natural fibers in the polymer composite industry is the incompatibility between the hydrophilic fibers and the hydrophobic polymer resin, which renders weak the int...

In Australia, the plastic solid waste (PSW) comprises 16% by weight of municipal solid waste but only about one-fourth are recycled. One of the best options to increase the recycling rate of mixed PSW is to convert them into products suitable for construction. However, a comprehensive understanding on the mechanical behaviour of mixed PSW under dif...

Geopolymer concrete reinforced with glass-fibre-reinforced polymer (GFRP) bars can provide a construction system with high durability, high sustainability, and adequate strength. Few studies deal with the combined use of these materials, and this has been the key motivation of this undertaking. In this study, the flexural strength and serviceabilit...

Crude oil spillage severely impacts the environment and affects the physical and chemical properties of the surrounding soil. Due to prohibitive cost of cleaning and disposing oil contaminated sand, mixing and stabilising them with cement and using them in construction is now considered as an alternative and cheap remediation method. In this paper,...

This study investigated the flexural response of glass fibre reinforced polymer-reinforced geopolymer concrete (GFRP-RGC) beams using a four-point static bending test. Three full-scale beams were cast and reinforced with nearly same amount of longitudinal GFRP reinforcements but of varying diameters at the bottom (4-12.7 mm, 3-15.9 mm, and 2-19.0 m...

A number of composite railway sleeper technologies have been developed but their applications in rail tracks are still limited. This paper rigorously reviews the recent developments on composite sleepers and identifies the critical barriers to their widespread acceptance and applications. Currently the composite sleeper technologies that are availa...

The use of oil-contaminated sand in building and construction is now being considered as an alternative and cost effective way to minimise its adverse effect on the environment. To achieve this, the effect of oil contamination on the important mechanical properties of sand should be investigated first. This study investigated the effect of petroleu...

Bamboo fibre reinforced composites are not fully utilised due to the limited understanding on their mechanical characteristics. In this paper, the effects of alkali treatment and elevated temperature on the mechanical properties of bamboo fibre reinforced polyester composites were investigated. Laminates were fabricated using untreated and sodium h...

Fibre reinforced polymer (FRP) bar has gained considerable acceptance as internal reinforcement for concrete structures because of its non-corrosive, lightweight, nonmagnetic, and high tensile strength properties while geopolymer concrete, normally manufactured using industrial waste materials like fly ash and blast furnace slags, has been successf...

The use of geopolymer concrete reinforced with fiber-reinforced polymer (FRP) bars is anticipated to address the concerns on the usage of traditional reinforced concrete structures, such as the corrosion of internal steel reinforcement, costly repair and rehabilitation, and development of sustainable infrastructures. To gain wide acceptance in the...

The FRP reinforced concrete structures may be exposed to high temperatures that may reduce the structural integrity of the bars, and eventually of the entire structure. Therefore, the thermal stability of the FRP bars must be thoroughly investigated before they can be fully utilized in the construction industry. The flexural strength testing has lo...

In recent years, there has been an increasing interest in seeking the potential applications of recycled mixed plastic wastes in building and construction sectors to relieve the pressure on landfills. This paper presents the recent developments and applications of composite materials made from recycled mixed plastics and glass fibre. Some of the fi...

Geopolymer concrete reinforced with glass fibre reinforced polymer (GFRP) bars is a new and emerging technology that is suitable for the construction of corrosion resistant, durable, and highly sustainable civil infrastructures. To encourage its utilisation in the construction industry, a better understanding on its bond mechanism should be gained...

The effectiveness of fibre reinforced polymer (FRP) composites jacket for pile rehabilitation relies mostly on the continuity of repair system. This paper presents the development of a new type of FRP jacket with an innovative, easy-fit and self-locking mechanical joining system and the evaluation of the suitability of this composite repair system...

Pultruded hollow composite sections have gained wide acceptance in civil engineering application due to their high strength, light weight and durability. However, pultruded composite are vulnerable to buckling due to their relatively low modulus of elasticity and thin-walled sections. This paper investigates the benefits of using low strength concr...

The ability to provide the joint versatility for pultruded fibre reinforced polymer (PFRP) in civil structures industry is crucial for its application demands. Bolted joint is extensively used in the industry due to low cost and ease of assembly. However, this jointing method can compromise the PFRP strength at the joint due to poor quality of dril...

Fibre reinforced polymer (FRP) composites have been proven a viable alternative to conventional construction materials such as timber, steel, and reinforced concrete due to its high strength-to-weight, light weight, durable, and corrosion resistant properties. Several studies suggested the effective use of FRP composites in sandwich structures. Thi...

Steel pipelines are widely used in the oil and gas industry. Over time, many pipelines experience internal metal loss, mainly due to corrosion, and some form of repair is required in order to reinstate the original operating capacity and maintain structural integrity. Fibre reinforced composites offer solutions with broad applicability and efficien...

The mechanical and thermal properties of the grouts are critical to their potential application as infill materials in structural repair. In this paper, the mechanical and thermal behaviour of five epoxy based grouts were investigated to identify their prospects as a component of the composite repair for steel pipelines. The compressive strength an...

The shear behaviour of structural sandwich beams made by gluing together fibre composite sandwich panels in the flatwise and in the edgewise positions was investigated with a view of using this material for construction and building applications. The effect of the number and orientation of sandwich laminations on the shear strength and failure beha...

Structures can go through harsh environmental adversity and can experience material loss and cracks during their service lives. Infill material is used to ensure a supporting bed for a grouted repair. Epoxy grouts are used for repairing and rehabilitating structures, such as foundations, bridges, piers, transportation pipelines, etc., because they...

Metal pipelines are the most efficient and safe ways for oil and gas transportation over a long distance. At present, almost all pipelines are made by ferrous steel which is sensitive to corrosion at harsh working environments, particularly in the presence of salty water and sulphur ingress media. For years, the most traditionally-credible solution...

This study has investigated the mechanical properties of the constituent materials of a novel structural composite sandwich panel developed for structural applications. Properly designed and carefully conducted experiments using coupon specimens following ISO and ASTM test standards were performed to characterize the flexural, tensile, compressive...

The applications of natural fibre/polymer composites in civil engineering are mostly concentrated on non-load bearing indoor components due to its vulnerability to environmental attack. This paper evaluates the characteristics of several natural fibre composites exposed to moisture, thermal, fire, and ultraviolet degradation through an extensive li...

This paper proposed a lifetime prediction model to characterise the damage response of square fibre-reinforced polymer (FRP) composite tubes under repeated axial impact. The model, which is a function of damage parameter D and normalised impact number Nf, used an energy-based approach. Series of impact and quasi-static compressive tests on composit...

The behaviour of structural fibre composite sandwich beams made up of glass fibre composite skins and phenolic core material was investigated under three-point short beam and asymmetrical beam shear tests. The effect of the shear span-to-depth ratio (a/D) on the strength and failure behaviour of the composite sandwich beams was examined. The result...

This paper presents the structural behaviour of an emerging prefabricated wall system made up of glass fibre reinforced rigid polyurethane foam (PUF) and Magnesium Oxide (MgO) board. Full-scale wall specimens were prepared and tested under transverse bending, compression and shear. The results of the experimental investigation showed that the behav...

The behaviour of structural glass fibre reinforced polymer (GFRP) composite sandwich slab was investigated under static point load. In this paper, the effects of dimensions aspect ratio, skin fibre orientations, overall thickness, boundary restraints, and boundary conditions on the static behaviour of the GFRP slab were presented. It was found that...

Series of impact tests were conducted to investigate the behaviour of fibre reinforced polymer (FRP) composite tubes under axial impact. The effects of damage parameters such as the mass of the impactor, incident energy and number of impacts on their behaviour were studied. The tests were performed by axially impacting 100 mm square FRP pultruded t...

Experimental investigations were performed to characterize the mechanical properties of bamboo fiber-polyester composites. The composite laminates were fabricated by infusing different forms of untreated bamboo fibers (randomly oriented, bamboo textiles and bamboo foam cores) with polyester resin. The results showed that the engineered bamboo fiber...

This paper presents an overview of the recent developments and initiatives on FRP trusses, which has been evolving and has become a viable construction system in civil infrastructure. The paper also discusses the different jointing systems used to assemble FRP components with the aim of determining the appropriate and reliable jointing connections...

The behaviour of a railway turnout system when one of the sleepers is replaced with a fibre composites sleeper is analyzed to simulate the spot replacement maintenance strategy. In the analysis, the rails and the sleepers are modeled as a simplified three dimensional grillage beam system with the sleepers as beams on elastic foundation. The most cr...

An experimental study on the flexural and shear behavior of the full-scale glue-laminated composite sandwich beams in three different layouts was conducted to evaluate the suitability of this construction system for railway turnout sleepers. The building block of this innovative beam is a novel composite sandwich structure made up of glass fiber co...

A hybrid Fibre Reinforced Polymer (FRP) composite for bridge girder application is now being developed in Japan. The innovative feature of this composite girder optimises the combined use of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP) for maximum structural performance while minimising the production cost. An ex...

The behaviour of glued composite sandwich beams in flexure was investigated with a view of using this material for structural and civil engineering applications. The building block of this glue-laminated beam is a new generation composite sandwich structure made up of glass fibre reinforced polymer skins and a high strength phenolic core material....