ORCID Profile
0000-0003-1619-9643
Current Organisation
University of Technology Sydney
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Civil Engineering | Construction Materials | Structural Engineering | Building Science and Techniques | Environmental Engineering not elsewhere classified | Infrastructure Engineering and Asset Management | Environmental Rehabilitation (excl. Bioremediation)
Cement and Concrete Materials | Civil Construction Design | Cement Products and Concrete Materials | Climate Change Adaptation Measures | Urban and Industrial Air Quality | Civil Building Management and Services | Management of Greenhouse Gas Emissions from Construction Activities | Civil Construction Processes | Metals (e.g. Composites, Coatings, Bonding) |
Publisher: Informa UK Limited
Date: 07-2009
Publisher: SAGE Publications
Date: 11-2015
DOI: 10.1260/1369-4332.18.10.1563
Abstract: This experimental research aims to investigate the possibility of using Carbon Fiber-Reinforced Polymer (CFRP) rods to strengthen in shear concrete structural members with the Near Surface Mounted reinforcement (NSM) technique. Seven reinforced concrete beams were tested in flexure with or without traditional shear reinforcement. Carbon-epoxy pultruded FRP (CFRP) rods with 6 mm in diameter were used. The possibility of using a mortar as filling material with surface pre-conditioned CFRP rod is investigated and compared to resin performance. Results show that NSM technique is very efficient to strengthen reinforced concrete beam in shear. Using the resin instead of mortar as the filling material still increases the efficiency of the shear strengthening but the gain is only moderate. The experimental results are compared with existing analytical models.
Publisher: Wiley
Date: 12-08-2014
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2011
Publisher: Elsevier BV
Date: 06-2016
Publisher: Elsevier BV
Date: 06-2009
Publisher: American Society of Civil Engineers (ASCE)
Date: 06-2015
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 11-2009
Publisher: Springer Science and Business Media LLC
Date: 11-03-2006
Publisher: Elsevier BV
Date: 03-2010
Publisher: Springer Singapore
Date: 04-09-2020
Publisher: Walter de Gruyter GmbH
Date: 09-04-2018
DOI: 10.1515/CORRREV-2017-0100
Abstract: In chloride environments, reinforcement stress limits, intended to control flexural cracking, are one of the most important requirements for service limit state (SLS) design. However, concrete damage at the steel-concrete interface between bending cracks, so called cover-controlled cracking, is always correlated to areas of severe steel reinforcement corrosion. Based on the assumption that cover-controlled cracking should be limited, a model has been developed to provide alternative reinforcement stress limits in marine exposure conditions such as concrete in sea water, including permanently submerged, spray zone and tidal/splash zone, as well as coastal constructions located within 1 km of the shoreline. In this paper, the new reinforcement stress limitation is compared to the Australian Standards AS3600 concrete building code and AS5100.5 concrete bridge code provisions. Analysis shows that the new model is very sensitive to the reinforcement percentage of the cross-section. As a result, the existing AS3600 and AS5100.5 code provisions are more conservative than the new limitation for lightly to normally reinforced concrete cross-section. In this case, crack width control governs the SLS design. However, for normally to heavily reinforced concrete cross-section, the new model provides more conservative results suggesting that cover-controlled cracking governs the SLS design.
Publisher: American Society of Civil Engineers (ASCE)
Date: 06-2014
Publisher: Thomas Telford Ltd.
Date: 05-2010
DOI: 10.1680/COMA.2010.163.2.97
Abstract: Chloride-induced corrosion in reinforced concrete leads to a reduction of the steel cross-section and deterioration of the steel–concrete bond. In this paper, experimental results are presented in order to clarify the respective influence of these degradations on beam serviceability (deflection). Pitting corrosion simulations were performed and two naturally corroded beams (14 and 23 years old) were analysed. Corrosion simulations have shown that the reduction in steel cross-section due to local pitting corrosion does not affect serviceability. Increased deflection is due to deterioration of the steel-concrete bond (reduction of concrete tension stiffening). Experimental results obtained on two corroded beams broken and analysed after 14 years and 23 years of chloride exposure showed that, during the natural chloride-induced corrosion process, the corrosion pattern evolves in relation to the corrosion cracking. Localised pitting corrosion is responsible for the initiation of corrosion cracking. Then, as the width of the cracks develops, general corrosion becomes gradually the main corrosion pattern. According to these experimental results, a mechanical model is proposed for serviceability assessment, which takes into account the evolution of the corrosion pattern from local pitting corrosion to general reinforcement corrosion.
Publisher: Informa UK Limited
Date: 03-05-2016
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 07-2010
Publisher: Thomas Telford Ltd.
Date: 03-2007
Publisher: Elsevier BV
Date: 11-2018
Publisher: Informa UK Limited
Date: 04-2012
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2018
Publisher: Elsevier BV
Date: 08-2019
Publisher: Elsevier BV
Date: 11-2016
Publisher: Springer Science and Business Media LLC
Date: 24-03-2016
DOI: 10.1617/S11527-015-0599-1
Abstract: The main purpose of this research is to study the time dependent behaviour of a geopolymer concrete. The geopolymer binder is composed of 85.2 % of low calcium fly ash and only 14.8 % of ground granulated blast furnace slag. Both drying shrinkage and creep are studied. In addition, different curing conditions at elevated temperature were used. All experimental results were compared to predictions made using the Eurocode 2. The curing regime plays an important role in the magnitude and development of both creep and drying shrinkage of class F fly ash based geopolymer concrete. A minimum of 3 days at 40 °C or 1 day at 80 °C is required to obtain final drying shrinkage strains similar to or less than those adopted by Eurocode 2 for ordinary Portland cement (OPC) concrete. Creep strains were similar or less than those predicted by Eurocode 2 for OPC concrete when the geopolymer concrete was cured for 3 days at 40 °C. After 7 days at 80 °C, creep strains became negligible.
Publisher: Elsevier BV
Date: 08-2009
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 12-2011
Publisher: American Concrete Institute
Date: 08-2017
DOI: 10.14359/51689898
Publisher: Springer Netherlands
Date: 2011
Publisher: Elsevier BV
Date: 07-2010
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2012
Publisher: Springer Netherlands
Date: 2011
Publisher: SAGE Publications
Date: 23-03-2018
Abstract: In this article, experiments focusing at the influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams are reported. In these experiments, the bond between concrete and reinforcing bar was damaged using appreciate flexural loads. The static stiffness of cracked reinforced concrete beam was assessed using the measured load–deflection response under cycles of loading and unloading, and the dynamic stiffness was analyzed using the measured natural frequencies with and without sustained loading. Average moment of inertia model (Castel et al. model) for cracked reinforced beams by taking into account the respective effect of bending cracks (primary cracks) and the steel–concrete bond damage (interfacial microcracks) was adopted to calculate the static load–deflection response and the natural frequencies of the tested beams. The experimental results and the comparison between measured and calculated natural frequencies show that localized steel–concrete bond damage does not influence remarkably the dynamic stiffness and the natural frequencies both with and without sustained loading applied. Castel et al. model can be used to calculate the dynamic stiffness of cracked reinforced concrete beam by neglecting the effect of interfacial microcracks.
Publisher: Springer Science and Business Media LLC
Date: 06-01-2009
Publisher: Trans Tech Publications, Ltd.
Date: 12-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.163-167.3415
Abstract: This paper deals with the steel/concrete interface of a corroded beam B2CL1 after a 23 years exposure in chloride environment. XRD, SEM and Raman techniques were performed to investigate the chemical compositions and the spatial distribution of corrosion products. The experimental results illustrate that the corrosion product layer is a multi-layer constituted as marbling structure. It is composed of a mix of iron oxides and iron oxi-hydroxides. Iron species were found in the vicinity of concrete mainly in cracks, as it was already observed in the literature.
Publisher: American Concrete Institute
Date: 09-2016
DOI: 10.14359/51688925
Publisher: Springer Science and Business Media LLC
Date: 22-10-2018
Publisher: Elsevier BV
Date: 2004
Publisher: Elsevier BV
Date: 04-2016
Publisher: Springer Science and Business Media LLC
Date: 02-2020
DOI: 10.1617/S11527-020-1449-3
Abstract: Many standardised durability testing methods have been developed for Portland cement-based concretes, but require validation to determine whether they are also applicable to alkali-activated materials. To address this question, RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ carried out round robin testing of carbonation and chloride penetration test methods, applied to five different alkali-activated concretes based on fly ash, blast furnace slag or metakaolin. The methods appeared overall to demonstrate an intrinsic precision comparable to their precision when applied to conventional concretes. The ranking of test outcomes for pairs of concretes of similar binder chemistry was satisfactory, but rankings were not always reliable when comparing alkali-activated concretes based on different precursors. Accelerated carbonation testing gave similar results for fly ash-based and blast furnace slag-based alkali-activated concretes, whereas natural carbonation testing did not. Carbonation of concrete specimens was observed to have occurred already during curing, which has implications for extrapolation of carbonation testing results to longer service life periods. Accelerated chloride penetration testing according to NT BUILD 443 ranked the tested concretes consistently, while this was not the case for the rapid chloride migration test. Both of these chloride penetration testing methods exhibited comparatively low precision when applied to blast furnace slag-based concretes which are more resistant to chloride ingress than the other materials tested.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Springer Science and Business Media LLC
Date: 03-03-2016
Publisher: Springer Science and Business Media LLC
Date: 22-06-2013
Publisher: Thomas Telford Ltd.
Date: 05-2012
Abstract: Deterioration of post-tensioned structures may take place as a consequence of severe environmental conditions or design or construction errors. This paper investigates analytically the effects of corrosion on the structural response of bonded post-tensioned beams. An experimental study on the stress corrosion of prestressing wires is described first, providing data on the steel behaviour. A series of tests on beams taken from the literature is then analysed. The breaking of a part of the wires was caused by artificial corrosion the beams showed stiffness and strength deterioration as a consequence of further breakages occurring under imposed load. Two different analytical approaches are used: macro finite-element analysis based on the calculation of the cross-section response and non-linear finite-element analysis. The analyses provide the global response and local strain values with the interpretation of the causes of the deterioration of the response.
Publisher: Elsevier BV
Date: 05-2017
Publisher: Thomas Telford Ltd.
Date: 07-2014
Abstract: This paper presents specific experiments developed to assess galvanic corrosion currents in carbonated concrete. The work investigated the influence of both the steel–concrete interface condition and the cathodic to anodic surface ratio. Galvanic corrosion currents were compared with microcell corrosion currents. In the quasi-saturated condition, galvanic corrosion currents were systematically found to be much higher than microcell corrosion currents. Moreover, the presence of defects at the interface between the anodic steel surface and concrete leads to a significant increase in the macrocell driving potential and, therefore, in the galvanic corrosion current. Furthermore, the galvanic current density strongly increased with increasing cathodic to anodic surface ratio. The coupling of a high cathodic to anodic surface ratio and the presence of steel–concrete interface defects at the anodic surface leads to huge galvanic corrosion current densities.
Publisher: Thomas Telford Ltd.
Date: 11-2019
Abstract: Experiments were carried out under ambient conditions and in a temperature–humidity control room to assess the influences of early-age shrinkage and tensile creep on cracking in reinforced-concrete (RC) members subjected to internal restraint. Two concrete mixes were considered, with compressive strengths of 36 MPa and 47 MPa. The evolution of the tensile creep coefficients was measured using unreinforced dog-bone-shaped specimens subjected to sustained axial tension. The shrinkage-induced stress tests were performed on RC prisms internally restrained by one concentrically placed reinforcement. Free shrinkage and restrained shrinkage were measured on companion plain concrete prisms and on unloaded RC prisms, respectively, to determine the degree of restraint. The results show that the 36 MPa concrete had a higher tensile creep coefficient than the 47 MPa concrete, but that there were no significant differences in early-age free shrinkage. A lower humidity results in more free shrinkage strain, but leads to more tensile creep and, consequently, increased relaxation of the tensile stresses. The magnitude of the restrained shrinkage depends on the reinforcement ratio. The development of the tensile strength of concrete is a governing factor influencing the time to cracking. The tensile ageing coefficient was calibrated for the two concrete mixes.
Publisher: Elsevier BV
Date: 02-2010
Publisher: Elsevier BV
Date: 09-2017
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 09-2010
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 2002
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2013
Publisher: Elsevier BV
Date: 10-2016
Publisher: Thomas Telford Ltd.
Date: 12-2018
Abstract: A major input to numerical simulation models used to predict the risk of early-age thermal cracking in concrete is the hydration heat estimation. The precision of hydration heat estimation models has been extensively verified for different cement compositions in previous studies. However, little has been done to investigate the accuracy of such models for concrete mixes containing supplementary cementitious materials and retarders. This paper presents the results of a series of isothermal calorimetry tests conducted first to investigate the effects of Class F fly ash, ground-granulated blast-furnace slag (GGBFS) and three commonly used retarders (namely, retarder N, sucrose and citrate) on the heat of hydration profile of Australian general-purpose cement under different curing temperatures of 10, 23 and 30°C, and second to evaluate the precision of the two most commonly used hydration heat models in capturing the effects of fly ash, GGBFS, retarders and curing temperature on the hydration profile. The results reveal the possibility of considerable errors in estimating the hydration heat of concrete mixes containing supplementary cementitious materials and retarders under different curing temperatures, highlighting the need for re-calibration of the existing models for locally used materials to avoid misleading errors in numerical simulation of early-age thermal cracking.
Publisher: Trans Tech Publications, Ltd.
Date: 09-2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.711.943
Abstract: Geopolymer concrete (GPC) has significant potential as a more sustainable, low-embodied carbon alternative for ordinary Portland cement concrete (PCC). However as a rather new engineering material, there are some concerns over the durability aspects of geopolymeric binders. In this study, performance of chloride contaminated reinforced GPC specimens manufactured using low calcium fly ash is investigated by long-term monitoring of corrosion parameters such as free corrosion potential and polarization resistance. It was found that low calcium fly ash GPC can perform as well as PCC during the propagation phase of corrosion although, some conventional reference values of corrosion parameters which are indicative of severity of the steel corrosion in PCC are not suitable for GPC. Additionally, commonly used electrochemical test methods are successfully employed to assess the degree of reinforcement corrosion in geopolymeric binders within an acceptable level of accuracy.
Publisher: Elsevier
Date: 2017
Publisher: Thomas Telford Ltd.
Date: 10-2011
DOI: 10.1680/MACR.2011.63.10.773
Abstract: This paper deals with the influence of the steel–concrete interface condition on the reinforcement corrosion in a chloride environment. Two large-sized concrete members were cast including horizontal reinforcements at different levels in order to create voids under the upper horizontal bars caused by the well-known ‘top-bar effect'. The walls were then sawn into small-sized specimens including one rebar. These small specimens were submitted to wetting–drying cycles in salt water (natural corrosion process). The polarisation resistance technique was performed to monitor the steel corrosion during the ageing up to 55 weeks. Chloride profiles were regularly measured and specimens were broken to observe the corrosion pattern. Results show that, first, a good-quality steel–concrete interface significantly reduces the corrosion rate in comparison with the specimen with interfacial defects. Second, before concrete cracking, the corrosion pattern observed is completely different between the specimens with or without defect. Perfect interface specimens show a typical local pitting corrosion pattern owing to chloride attack. However, specimens affected by the ‘top-bar effect' show a generalised corrosion along the steel surface affected by the void (surface under the horizontal steel bars in regard to concrete casting direction). Macrocell corrosion seems to develop between the lower surface affected by the void acting as an anode and the upper surface where the bond is perfect as the cathode. The concrete cracking is delayed for specimens affected by the ‘top-bar effect' in spite of a higher corrosion rate. This delay can be attributed to the time necessary for the rust to fill the voids.
Publisher: Elsevier BV
Date: 02-2014
Publisher: Elsevier BV
Date: 10-2016
Publisher: Thomas Telford Ltd.
Date: 04-2003
DOI: 10.1680/MACR.2003.55.2.151
Abstract: To evaluate the degree of corrosion, reinforcements of 14-year-old and 17-year-old concrete members were completely exposed. These 3 m long beams were stored in three-point flexion in an aggressive environment consisting in sequences of drying and wetting by a salt fog (35 g/l of NaCl). The total chloride content was also measured at the level of all reinforcements. The chloride content appears to be significantly higher than the threshold that is generally used to evaluate corrosion initiation. A comparative analysis carried out on these experimental results shows that the steel–concrete interface quality (physical adhesion between steel and concrete) is greatly determinant to predict the initiation of corrosion in reinforced concrete members.
Publisher: EDP Sciences
Date: 11-2006
Publisher: Informa UK Limited
Date: 2015
Publisher: Elsevier BV
Date: 11-2007
Publisher: Informa UK Limited
Date: 2014
Publisher: Springer Science and Business Media LLC
Date: 19-11-2010
Publisher: Thomas Telford Ltd.
Date: 02-2015
Abstract: This paper discusses the advantages of using low-calcium fly ash (FA)-based geopolymer concrete (GPC) for precast applications when high early-age strength is required. Heat curing is known to be the reaction accelerator for both Portland cement (OPC) concrete and the newly emerged GPC. Here, the influence of 12 different heat-curing regimes, as well as internal curing, on mechanical properties of an FA-based GPC is investigated. The curing regimes include three temperatures of 60, 75 and 90°C, and four curing durations of 8, 12, 18 and 24 h. Results are compared with that of OPC concrete counterpart, with the same amount of binder and aggregate. Test results show that, in optimum heat-curing conditions, GPC can achieve more than 90% of its 28 d compressive strength after 1 d, compared to only 55% to 71% for normal concrete. The optimum heat-curing regime for GPC, combining best performance and energy efficiency, is found to be 75°C for 18 h. Contrary to conventional concrete, heat curing has no detrimental effect on the long-term compressive strength of GPC. It is concluded that, for precast applications, FA-based GPC appears to perform better than OPC concrete in terms of both early and long-term compressive strength using the same amount of binder.
Publisher: American Society of Civil Engineers
Date: 08-11-0110
Publisher: Elsevier BV
Date: 09-2020
Publisher: American Concrete Institute
Date: 2018
DOI: 10.14359/51700952
Publisher: SAGE Publications
Date: 12-2013
DOI: 10.1260/1369-4332.16.12.2035
Abstract: The method proposed in this paper aims to assess both the irreversible deflection of cracked reinforced concrete beams when unloaded and their overall stiffness under loading cycles which is relevant for in-situ analysis of existing structures. Only service stage is modeled and time-dependent effects such as creep and shrinkage are not taken into account. The modeling approach combines an existing model based on an empirical moment-curvature analytic relationship with a new Macro-Finite-Element (MFE) both implemented in a linear finite element analysis. MFEs are Beam Finite Elements, characterized by their average moment of inertia. The average moment of inertia is calculated by homogenization of the steel strain, concrete strain and neutral axis modeled between two consecutive bending cracks. The results of the MFE model have been successfully compared to experiments. The irreversible deflection represents a significant proportion of the total deflection in service and the overall stiffness of the cracked beams during the loading cycles is strongly under-estimated by existing models based on empirical moment-curvature relationships.
Publisher: Springer Science and Business Media LLC
Date: 16-06-2006
Publisher: Wiley
Date: 21-12-2015
Publisher: Informa UK Limited
Date: 07-2013
Publisher: Elsevier BV
Date: 09-2018
Publisher: Thomas Telford Ltd.
Date: 10-2019
Abstract: This paper presents the results of an investigation on the use of synthetic polypropylene (PP) and polyolefin (PO) fibres to improve the creep and shrinkage performance of low-calcium fly ash-based geopolymer concrete. Three PP fibres of 18, 19 and 51 mm length and two PO fibres of 48 and 55 mm length with a volume fraction of 0·5% were added to geopolymer concrete. The mechanical properties of the resulting material, such as compressive and splitting tensile strength, modulus of elasticity and modulus of rupture, have been studied. The drying shrinkage and creep of plain and fibre-reinforced geopolymer concrete were examined for a period of 1 year. The results revealed that the inclusion of PP and PO fibres in a volume fraction of 0·5% decreased the drying shrinkage and increased the compressive creep of fly ash-based geopolymer concrete at both early ages and in the long term.
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2018
Publisher: Elsevier BV
Date: 10-2016
Publisher: Elsevier BV
Date: 10-2007
Publisher: Elsevier BV
Date: 11-2009
Publisher: Elsevier BV
Date: 08-2016
Publisher: Elsevier BV
Date: 04-1999
Publisher: Elsevier BV
Date: 02-2018
Publisher: Informa UK Limited
Date: 04-2012
Publisher: Thomas Telford Ltd.
Date: 09-2007
Publisher: Springer Science and Business Media LLC
Date: 10-09-2019
DOI: 10.1617/S11527-019-1396-Z
Abstract: The aim of RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ is to identify and validate methodologies for testing the durability of alkali-activated concretes. To underpin the durability testing work of this committee, five alkali-activated concrete mixes were developed based on blast furnace slag, fly ash, and flash-calcined metakaolin. The concretes were designed with different intended performance levels, aiming to assess the capability of test methods to discriminate between concretes on this basis. A total of fifteen laboratories worldwide participated in this round robin test programme, where all concretes were produced with the same mix designs, from single-source aluminosilicate precursors and locally available aggregates. This paper reports the mix designs tested, and the compressive strength results obtained, including critical insight into reasons for the observed variability in strength within and between laboratories.
Publisher: Informa UK Limited
Date: 04-2012
Publisher: Elsevier BV
Date: 08-2009
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 06-2012
Start Date: 05-2016
End Date: 08-2019
Amount: $370,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 01-2019
End Date: 01-2023
Amount: $321,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 2022
End Date: 12-2024
Amount: $220,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 10-2021
End Date: 10-2024
Amount: $230,636.00
Funder: Australian Research Council
View Funded ActivityStart Date: 08-2016
End Date: 08-2020
Amount: $450,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 02-2016
End Date: 12-2018
Amount: $299,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 02-2014
End Date: 11-2017
Amount: $300,000.00
Funder: Australian Research Council
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