ORCID Profile
0000-0001-8478-8103
Current Organisation
RMIT University
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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 | Structural Engineering | Construction Materials | Stochastic Analysis And Modelling | Urban and Regional Planning not elsewhere classified | Civil Engineering Not Elsewhere Classified | Electrochemistry |
Preserving the built environment | Cement and Concrete Materials | Industry | Cement and concrete materials | Civil Construction Design | Environmentally Sustainable Construction not elsewhere classified | Environmentally Sustainable Manufacturing not elsewhere classified | Cement Products and Concrete Materials
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 06-2022
Publisher: Thomas Telford Ltd.
Date: 05-2006
DOI: 10.1680/MACR.2006.58.4.221
Abstract: This paper reports results of an experimental programme to measure changes in bond characteristics of plain round reinforcement as a result of corrosion. Principal parameters included in the investigation are the amount of corrosion, the presence of confining reinforcement in the form of links, cover thickness and the initial condition of the reinforcement. In the absence of confining links, bond strength of bars cast near the bottom of a pour is found to reduce with increasing corrosion. However, although top-cast bars were initially weaker, small amounts of corrosion were sufficient to raise bond strength to that of bottom-cast bars. With increasing corrosion, strength reduced in a similar manner to bottom-cast bars. Confining reinforcement had little influence on bond strength prior to the onset of corrosion, but plays an important role in maintaining strength once corrosion becomes established. Results from these tests suggest that surface crack width may provide a better parameter than section loss or corrosion penetration through which to assess residual bond strength. The reasons for this are explained, and empirical relationships for residual strength are derived.
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 09-2001
Publisher: Elsevier BV
Date: 10-2021
Publisher: IOP Publishing
Date: 04-2023
DOI: 10.1088/1755-1315/1157/1/012024
Abstract: The production of Portland Cement (PC) has been shown to be responsible for 5-8% of global CO2 emissions. This has led to class F fly ash based geopolymer concrete being developed as a substiture for PC concrete for to reduce these global CO2 emissions. However, research has shown that each fly ash has unique characteristics and requires a specific mix design for each fly ash. This is can occupy a significant amount of time. Furthermore, before the mix can be adopted for commercial application it requires the long-term durability to be established. This gap is one of the primary limitations delaying the adoption of geopolymer concrete. While each fly ash is unique, they do have common characteristics which can be utilized to optimise the mix design process. Geopolymers are also known to have good durability characteristics, in particular for acid and sulphate exposure. This paper reports the mix design optimisation process for six class F fly ashes from Australia, Sri Lanka and Indonesia. The strength properties and durability performance of the optimised mixes is reported including the compressive strength development, chloride and carbonation resistance together with performance when exposed to sulphate and acidic media for the Indonesian fly ash, including to a simulated peat soil designed to replicate the conditions experienced in Indonesia.
Publisher: MDPI AG
Date: 08-05-2023
DOI: 10.3390/SU15097718
Abstract: Traditionally, the construction industry has predominantly used Portland cement (PC) to manufacture bricks, as it is one of the most-commonly available building materials. However, the employment of waste industrial material for brick production can lead to a significant improvement in terms of sustainability within the construction sector. Geopolymer bricks made from brown coal fly ash, a promising industrial waste by-product, serve as a potential alternative. Conducting a life cycle assessment (LCA), this study thoroughly evaluated the entire manufacturing process’s environmental impact, from source material acquisition and transportation to brick manufacturing, distribution, usage, and end-of-life, for brown coal bricks as compared to PC bricks. The LCA of the brown coal bricks revealed that their primary environmental impacts stemmed from the raw material manufacturing and usage, while exhibiting substantial reductions in ozone depletion, water depletion, and metal depletion. These findings highlighted the environmental advantages of the brown coal bricks and their potential to revolutionize sustainable construction practices.
Publisher: Elsevier BV
Date: 2021
Publisher: Informa UK Limited
Date: 10-05-2021
Publisher: Informa UK Limited
Date: 03-07-2019
Publisher: Elsevier BV
Date: 10-2016
Publisher: Springer Science and Business Media LLC
Date: 09-12-2022
Publisher: Elsevier BV
Date: 2023
Publisher: Springer Nature Singapore
Date: 29-09-2023
Publisher: MDPI AG
Date: 02-08-2019
DOI: 10.3390/APP9153138
Abstract: This study reports the effect of heat curing at 120 °C on the geopolymeric reaction and strength evolution in brown coal fly ash based geopolymer mortar and concrete. Moreover, an examination of this temperature profile of large size geopolymer concrete specimens is also reported. The specimen temperature and size were observed to influence the conversion from the glassy (amorphous) phases to the crystalline phases and the microstructure development of the geopolymer. The temperature profile could be ided into three principal stages which correlated well with the proposed reaction mechanism for class F fly ash geopolymers. The geopolymerisation progressed more rapidly for the mortar specimens than the concrete specimens with 12 to 14 h providing an optimum curing time for the 50 mm mortar cubes and 24 h being the optimum time for the 100 mm concrete cubes. The 50 mm and 100 mm concrete specimens’ compressive strengths in excess of 30 MPa could be obtained at 7 days. The structural integrity was not achieved at the center of 200 mm and 300 mm concrete specimens following 24 h curing at 120 °C. Hence, the optimal curing time required to achieve the best compressive strength for brown coal geopolymer was identified as being dependent on the specimen size.
Publisher: American Concrete Institute
Date: 10-2017
DOI: 10.14359/51689779
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2023
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 10-2020
Publisher: Thomas Telford Ltd.
Date: 07-2013
Abstract: The attack of concrete owing to sulfate present in sewage is a major problem, both in Australia and worldwide. The prediction of the expected long-term performance of concrete exposed to sewerage and similar environments can be difficult as it is affected by a large number of parameters. In addition the deterioration process in concrete takes a long time to reach a significant level. Whereas considerable research has been undertaken in flowing sewage systems in pipes, little research has been undertaken on static systems contained in septic tanks. A research project conducted at RMIT University has investigated the deterioration of concrete septic tanks located in rural Victoria. A comprehensive set of laboratory experiments was established to measure the accelerated deterioration of concrete under exposure to sulfuric acid. The specimens were manufactured using the same mix design and ingredients used in septic tank production in rural Victoria prior to 1990. The mass changes in the concrete specimens have been recorded and based on the data, a statistical model has been developed to predict the mass change of concrete with time as a function of the cement content and acid concentration observed in sewage.
Publisher: MDPI AG
Date: 15-03-2021
Abstract: Despite extensive in-depth research into high calcium fly ash geopolymer concretes and a number of proposed methods to calculate the mix proportions, no universally applicable method to determine the mix proportions has been developed. This paper uses an artificial neural network (ANN) machine learning toolbox in a MATLAB programming environment together with a Bayesian regularization algorithm, the Levenberg-Marquardt algorithm and a scaled conjugate gradient algorithm to attain a specified target compressive strength at 28 days. The relationship between the four key parameters, namely water/solid ratio, alkaline activator/binder ratio, Na2SiO3/NaOH ratio and NaOH molarity, and the compressive strength of geopolymer concrete is determined. The geopolymer concrete mix proportions based on the ANN algorithm model and contour plots developed were experimentally validated. Thus, the proposed method can be used to determine mix designs for high calcium fly ash geopolymer concrete in the range 25–45 MPa at 28 days. In addition, the design equations developed using the statistical regression model provide an insight to predict tensile strength and elastic modulus for a given compressive strength.
Publisher: Association for Materials Protection and Performance (AMPP)
Date: 2000
DOI: 10.5006/1.3280522
Publisher: Elsevier
Date: 2021
Publisher: ISEC Press
Date: 07-2017
DOI: 10.14455/ISEC.RES.2017.98
Abstract: Substantial researches have already been carried out on alkali-activated binders for the production of geopolymer concrete but studies on clay-based geopolymer concrete is still insufficient. The aim of this paper is to identify the effect of curing temperature on the properties of 100% clay-based geopolymer concrete. Clay pre-treated at 80°C and 120°C for 24 hours were selected as the source binder material. Four Activator Modulus (AM) 1.0, 1.25, 1.5 and 1.75 for each of two Sodium Oxide (Na 2 O) dosages of 10% and 15% were selected as the activator material for this investigation. X-ray diffraction (XRF) was applied to characterize the clay material. Specimens were cured at 80°C and 120°C for 24 hours. Specimens were tested under compression at seven, 14, 28 and 40 days. Specimens cured at 80°C took a longer duration ( days) to achieve structural integrity while the specimens cured at 120°C achieved structural integrity within seven days. Compressive strength of specimens prepared with AM of 1.0 for both of the Na 2 O dosage of 10% and 15% exhibited superior performance to other AMs investigated.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 03-2023
Publisher: Elsevier BV
Date: 12-2021
Publisher: Informa UK Limited
Date: 29-01-2022
Publisher: American Concrete Institute
Date: 11-2018
DOI: 10.14359/51706846
Publisher: Elsevier BV
Date: 07-2022
Publisher: Japan Concrete Institute
Date: 17-03-2015
DOI: 10.3151/JACT.13.187
Publisher: EDP Sciences
Date: 2019
DOI: 10.1051/MATECCONF/201928903005
Abstract: Recent studies have suggested that residual protection is afforded to structures following the application of impressed current cathodic protection (ICCP), in some cases for significant periods of time, while others for periods of only a few days. This study reported the findings of the de-activation of a 20 year old ICCP system installed on a 50 year old structure. The ICCP was de-activated for 84 days and the steel potentials at locations on the front pile cap and front wall were monitored via the installed reference electrodes. An adjacent water anode system was also de-activated for 48 hours during the initial de-activation period to observe the impact on the steel potentials. The results showed that out of 42 reference electrodes, 17 achieved a 100 mv decay within 24 hours and 10 had more positive instant off potentials than -150 mV. Furthermore, all displayed a positive shift in potential following deactivation of the ICCP system for a period of time, indicative of residual protection, with 22 displaying this positive shift for the whole 94 days of the trial.
Publisher: Springer Science and Business Media LLC
Date: 11-08-2022
Publisher: Informa UK Limited
Date: 06-11-2020
Publisher: EDP Sciences
Date: 2019
DOI: 10.1051/MATECCONF/201928903001
Abstract: One of the most effective techniques to mitigate corrosion of steel reinforcement in concrete is impressed current cathodic protection (ICCP). This technique has been widely used for several decades however, there is limited research systematically studying the various factors affecting the distribution of cathodic current over the area of steel reinforcement. Understanding how current is distributed in an ICCP system is crucial for its design to ensure that all areas of steel are sufficiently protected, and overprotection of certain areas is avoided. In this study, the effect of distance of the anode from the steel and level of corrosion on current distribution is investigated by applying a potential sweep and measuring the steel potential and current for specimens with three layers of steel at different depths. The findings from this study revealed an inverse relationship between cathodic polarisation with steel distance from the anode and that higher levels of corrosion can cause a more non-uniform current distribution favouring the closest bar to the anode.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Springer Science and Business Media LLC
Date: 19-02-2014
Publisher: Springer Singapore
Date: 25-10-2021
Publisher: Thomas Telford Ltd.
Date: 09-2022
Abstract: The incorporation of a high volume of fly ash (FA) (up to 80%) in concrete without compromising mechanical and durability properties is potentially very advantageous to the concrete industry in terms of economic, social and environmental benefits. The compressive strength, carbonation, chloride ion penetration, water absorption and permeability of two high-volume FA mix designs incorporating 80% class F ultrafine FA (known as microash) and hydrated lime, with and without the addition of silica fume (SF) were investigated in this study. The specimens were cured for a maximum of 90 days to optimise completion of the hydration reaction. The concrete containing with 80% microash exhibited compressive strength in excess of 40 MPa at 28 days and over 70 MPa at 90 days. The material also displayed excellent durability properties compared with normal Portland cement concrete and other high-volume FA concretes. The addition of SF (10%) further improved the strength and durability properties of the material.
Publisher: CRC Press
Date: 26-09-2019
Publisher: Trans Tech Publications, Ltd.
Date: 11-2018
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.789.69
Abstract: Steel fiber reinforced concrete (SFRC) is developed traditionally from ordinary concreteadmixed with randomly distributed steel fibers. The matrix of SFRC is always formed by adjustingthe mix proportion used for the ordinary concrete, which plays the role of controlling the properties ofSFRC. In this paper, the mix proportion of self-compacting concrete (SCC) compared with vibrationcompacted concrete (VCC) is statistically analyzed. A predictive formula for water-binder ratio isproposed in relation to the designed compressive strength of SCC and the cement strength affected bymineral admixtures. It is expected to provide reference for the mix proportion design for flowing andhigh-flowing SFRC.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4388126
Publisher: Springer Science and Business Media LLC
Date: 03-01-2019
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2017
Publisher: Thomas Telford Ltd.
Date: 03-2022
Abstract: The corrosion of steel due to chloride ingress is one of the major causes of deterioration of reinforced concrete structures. In order to ensure a structure achieves the design life specified, predictive modelling is employed. To undertake this modelling, details are required on a number of variables however, each of these variables has a level of uncertainty which can affect the reliability of the model. To address these issues, this paper reports the analysis of data taken from four distinct elements on a port structure, in Australia, constructed in three phases between 1926 and 1985, using both pre-cast and cast in situ techniques. The cover depth, surface chloride concentration and chloride diffusion coefficient were determined for different elements on the structure, with a total of 244 data points obtained. The data was analysed to identify the statistical distributions and probability density functions produced. A novel analytical model was developed based on the solutions to Fick's equation. The results showed that both surface chloride and the diffusion coefficient were positively skewed with no significant variation in the sensitivity. It was also found that controlling the diffusion coefficient has a more influential effect than increasing the cover.
Publisher: American Concrete Institute
Date: 09-2022
DOI: 10.14359/51735954
Publisher: Elsevier BV
Date: 08-2020
Publisher: Hindawi Limited
Date: 13-02-2018
DOI: 10.1002/STC.2156
Publisher: Trans Tech Publications, Ltd.
Date: 11-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMM.238.350
Abstract: A research project continuing at RMIT University is exploring the resilience of port structures in a changing climate. Research completed to date comprises of identifying types of port infrastructure vulnerable to climate change, establishing materials and exposure conditions, developing deterioration models based on current knowledge to simulate the effect of climate change on key port infrastructure and modeling the selected elements of infrastructure to derive outcomes which will aid in decision making in port infrastructure management. A considerable effort has been concentrated on identifying input climate data most appropriate for the models developed. The modeling approach is presented in this paper for quantitative projections of damage probability on port infrastructure taking into account the variability of material type, design considerations and environmental exposures with a changing climate. This paper provides a summary of the research undertaken in the development of material deterioration models and their responses to a changing climate load. Using climate information drawn from historical weather records and future climate projections, existing deterioration models were refined to include climate data into modeling runs in order to analyse changes to deterioration rates of different materials when impacted by a change in climate variables. Outputs from this modeling process will assist port authorities in making informed decisions on maintenance and capital budget planning allowing for impacts of climate change.
Publisher: Thomas Telford Ltd.
Date: 10-2017
Abstract: In this study, the effects of the mix flowability on the steel fibre distribution patterns and mechanical properties of steel-fibre-reinforced concrete (SFRC) were investigated. Slump ranging from 80 mm to 200 mm was employed as the parameter to reflect the flowability of SFRC. The results showed that an increase of flowability had no influence on the orientation of steel fibres and led to a decrease of sectional uniformity. Steel fibres orientated in the longitudinal direction of higher-flowability SFRC tended to precipitate toward the bottom layer of the specimens. This resulted in much better flexural performance, including flexural toughness and fracture energy. Analysis of the data suggested that instead of studying the whole cross-section, the distribution rate and distribution coefficient of steel fibres in the tensile zone of specimens should be considered as the main factor determining flexural performance of SFRC. Calculations for bending stiffness and flexural stress based on the distribution rate of high-flowability SFRC are recommended. Moreover, owing to the layering effect of steel fibres, traditional test methods were identified as being unsuitable for determining the mechanical properties of SFRC, indicating that further investigation is required.
Publisher: ISEC Press
Date: 11-2014
DOI: 10.14455/ISEC.RES.2014.41
Abstract: This study investigates the durability of basalt fiber following immersion in a range of chemical solutions representative of the concrete medium. The tests were conducted over a 62-day period and the solutions were sodium hydroxide, sodium chloride, sodium sulfate and combinations of the three. Weight loss was observed in all alkali solutions, with the worst being the combination of sodium hydroxide with sodium sulfate. The impact of chloride was minimal in the alkaline environment and reduced the impact of the sulfate when both were present. Microstructure analysis using a Scanning Electron Microscope (SEM) found that the silica structure present in basalt fibers was degraded by the OH-from an alkaline medium. The study suggests the need for modification or treatment of basalt fibers before use as fiber reinforcement in concrete.
Publisher: American Concrete Institute
Date: 09-2019
DOI: 10.14359/51716815
Publisher: Springer Science and Business Media LLC
Date: 10-02-2012
Publisher: American Society of Civil Engineers (ASCE)
Date: 11-2018
Publisher: Elsevier BV
Date: 2000
Publisher: Author(s)
Date: 2017
DOI: 10.1063/1.5003513
Publisher: Elsevier BV
Date: 2007
Publisher: Trans Tech Publications, Ltd.
Date: 10-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.368-373.790
Abstract: As a part of the collaborative studies between China, Australia and the UK, examing sulfate attack on concrete, this paper reports the experimental results obtained from the Chinese laboratory. Specimens were immersed in sodium and magnesium sulfate solutions with concentrations of 500mg/L, 5000mg/L and 50000mg/L. Investigations were conducted over approximately a one year period. Susceptibility to sulfate attack was assessed in terms of changes in the mass and length of specimens, the compressive strength of the concrete, as well as the diffusion depth of sulfate-ions into the concrete at fixed intervals. Several differences were observed between these results and those reported in studies from the UK laboratory.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Trans Tech Publications, Ltd.
Date: 07-2013
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.569-570.207
Abstract: Port infrastructure is vulnerable to the corrosive marine environment leading to deterioration, loss of functionality, delays in shipping, major maintenance, remediation and, in the worst cases, loss of structural integrity and consequent replacement of the asset. Despite this, asset managers are unable to adequately plan for the prevention and minimisation of maintenance due to a lack of reliable predictive tools, that simulate the deterioration and a lack of a lifecycle model incorporating protection/maintenance options. This paper reports on a project to develop such a tool to facilitate the probabilistic modelling of the deterioration of reinforced concrete elements from construction through onset of corrosion to subsequent cracking and spalling. The Australian government funded project is in collaboration with several port authorities. The study has narrowed the key factors that have the most impact on the estimation of corrosion initiation and damage propagation allowing better definition of what data should be collected, how much and levels of accuracy required to ensure that predictive outputs obtained are as ‘robust’ as possible.
Publisher: Elsevier BV
Date: 2015
Publisher: Informa UK Limited
Date: 2015
Publisher: Thomas Telford Ltd.
Date: 08-2013
Abstract: The pollution of water through release of hydroxyl ions from freshly cast concrete exposed to water can have a detrimental effect on aquatic life by causing a rise in pH. The concentration of hydroxyl ions leached from concrete can be affected by a number of factors. A detailed study has been undertaken to ascertain the effect of parameters such as flow rate, age of concrete after exposure, air quality, cement type, surface area and the volume of concrete. This paper presents the results of the experimental programme and a predictive model for change of pH of water after exposure to freshly cast concrete. Analysis of the results showed that the flow rate was the most significant factor in both the peak pH observed and the time to the peak pH. The volume of the s le was also identified as being a significant factor in the peak pH.
Publisher: Springer Science and Business Media LLC
Date: 05-11-2020
Publisher: Springer Science and Business Media LLC
Date: 16-08-2023
DOI: 10.1617/S11527-023-02224-7
Abstract: It has been reported that structures to which impressed current cathodic protection (ICCP) has been applied for a long period have displayed evidence of residual protection when ICCP has been halted, ranging from several days up to significantly longer periods. To study this phenomenon this paper reports the de-activation of a 20 years old ICCP system installed on a 55 years old wharf structure. The ICCP was de-activated for 84 days and the reinforcing steel potentials at locations on the front pile cap and front wall were monitored via the existing installed reference electrodes (RE). The results showed that all the RE installed in the structure initially demonstrated a positive shift in potential, with 61% maintaining a positive trend over the entire trial period.
Publisher: Walter de Gruyter GmbH
Date: 06-2020
DOI: 10.1515/CORRREV-2019-0108
Abstract: Buried pipelines are essential for the delivery of potable water around the world. A key cause of leaks and bursts in these pipelines, particularly those fabricated from carbon steel, is the accelerated localized corrosion due to the influence of microbes in soil. Here, studies conducted on soil corrosion of pipelines' external surface both in the field and the laboratory are reviewed with a focus on scientific approaches, particularly the techniques used to determine the action and contribution of microbiologically influenced corrosion (MIC). The review encompasses water pipeline studies, as well as oil and gas pipeline studies with similar corrosion mechanisms but significantly higher risks of failure. Significant insight into how MIC progresses in soil has been obtained. However, several limitations to the current breadth of studies are raised. Suggestions based on techniques from other fields of work are made for future research, including the need for a more systematic methodology for such studies.
Publisher: MDPI AG
Date: 28-07-2020
DOI: 10.3390/APP10155207
Abstract: Quarry aggregate reserves are depleting rapidly within Australia and the rest of the world due to an increasing demand for aggregates driven by expansion in construction. The annual production of premix concrete in Australia is approximately 30 million cubic meters, while 3–5% of concrete delivered to site remains unused and is disposed of in landfill or crushing plants. The production of coarse aggregates using this waste concrete is potentially a sustainable approach to reduce environmental and economic impact. A testing program has been conducted to investigate mechanical performance and permeation characteristics of concrete produced using a novel manufactured coarse aggregate recycled directly from fresh premix concrete. The recycled coarse aggregate (RCA) concrete satisfied the specified 28-day design strength of 25 MPa and 40 MPa at 28 days and a mean compressive strength of 60 MPa at 90 days. Aggregate grading was observed to determine strength development, while low water absorption, low drying shrinkage, and higher packing density indicate that the RCA concrete is a high-quality material with a dense pore structure. The rough fracture surface of the aggregate increased the bond between C-S-H gel matrix and RCA at the interfacial transition zone. Furthermore, a good correlation was observed between compressive strength and all other mechanical properties displayed by the quarried aggregate concrete. The application of design equations as stated in Australian standards were observed to provide a conservative design for RCA concrete structures based on the mechanical properties.
Publisher: Thomas Telford Ltd.
Date: 06-2008
Abstract: This paper describes experimental work to investigate the effect of reinforcement corrosion on the behaviour of concrete beams reinforced with plain round bars. Particular attention is paid to the bond between reinforcement and concrete. Four groups of beam specimens were tested, each designed to investigate specific aspects of structural performance including stiffness and deflection under service loads, ultimate flexural and shear strengths and deformation capacity at failure. Beams were conditioned to induce loss of cross-sectional reinforcement of up to 10% owing to corrosion, equivalent to 0·3 mm corrosion penetration, and longitudinal crack widths of 1·0 mm. Flexural stiffness of specimens detailed for a flexural mode of failure was not impaired by corrosion. Strength of beams with corroded bars equalled or exceeded that of companion non-corroded specimens in all cases, despite loss of bar section. It is concluded that an enhancement of anchorage capacity, believed to be associated principally with increased radial stresses on the bar–concrete interface in the vicinity of the end reactions, was able to offset loss of bar section.
Publisher: MDPI AG
Date: 12-02-2021
DOI: 10.3390/APP11041648
Abstract: The potential application of alkali-activated material (AAM) as an alternative binder in concrete to reduce the environmental impact of cement production has now been established. However, as the production and availability of the primarily utilized waste materials, such as fly Ash and blast furnace slag, decrease, it is necessary to identify alternative materials. One such material is clay, which contains aluminosilicates and is abundantly available across the world. However, the reactivity of untreated low-grade clay can be low. Calcination can be used to activate clay, but this can consume significant energy. To address this issue, this paper reports the investigation of two calcination methodologies, utilizing low-temperature and high-temperature regimes of different durations, namely 24 h heating at 120 °C and 5 h at 750 °C and, and the results are compared with those of the mechanical performance of the AAM produced with untreated low-grade clay. The investigation used two alkali dosages, 10% and 15%, with an alkali modulus varying from 1.0 to 1.75. An increase in strength was observed with calcination of the clay at both 120 and 750 °C compared to untreated clay. Specimens with a dosage of 10% showed enhanced performance compared to those with 15%, with Alkali Modulus (AM) of 1.0 giving the optimal strength at 28 days for both dosages. The strengths achieved were in the range 10 to 20 MPa, suitable for use as concrete masonry brick. The conversion of Al (IV) is identified as the primary factor for the observed increase in strength.
Publisher: Elsevier BV
Date: 07-2021
Publisher: American Concrete Institute
Date: 05-2017
DOI: 10.14359/51689454
Publisher: MDPI AG
Date: 23-12-2023
DOI: 10.3390/MA16010149
Abstract: The utilization of sustainable cement replacement materials in concrete can control the emission of carbon dioxide and greenhouse gases in the construction industry, thus contributing significantly to the environment, society, and the global economy. Various types of sustainable concrete including geopolymer concrete are tested for their efficacy for construction in laboratories. However, the performance and longevity of sustainable concrete for civil engineering applications in corrosive environments are still debatable. This paper aims to investigate the performance of the reinforced geopolymer (GPC) and foam concretes (FC) against corrosive chloride exposure. Two long term key parameters, i.e., corrosion rate and mechanical performance of reinforcing steel in geopolymer and foam concrete were assessed to evaluate their performance against chloride attack. For experiments, reinforced GPC and FC specimens, each admixed with 3 and 5% chlorides, were kept at varying temperatures and humidity levels in the environmental chambers. The corrosion rates of the reinforced geopolymer and foam concrete specimens were also compared with control specimens after 803 days and the tensile strength of the corroded reinforcing steel was also determined. Moreover, the long term efficacy of repaired patches (810 days), in a chloride-rich surrounding environment utilizing FC and GPC, was investigated. The results suggested greater performance of FC compared to GPC under standard environmental conditions. However, the simulated patch repair with GPC showed better resistance against chloride attack compared to FC. The research also undertook the fractographical examination of the surfaces of the reinforcement exposed to 5% admixed chloride and develops models for the corrosion rates of foam concrete as a function of the corrosion rates of geopolymer concrete and chloride content. A correlation model for the corrosion rates of FC and GPC was also developed. The findings of the current research and the model developed are novel and contribute to the knowledge of long term degradation science of geopolymers and form concrete materials. Furthermore, the findings and methodology of the current research have practical significance in the construction and repair industry for determining the remaining service life for any reinforced and steel infrastructure.
Publisher: Elsevier BV
Date: 06-2019
Publisher: Springer International Publishing
Date: 2021
Publisher: Elsevier BV
Date: 11-2021
Publisher: American Society of Civil Engineers (ASCE)
Date: 2023
Publisher: Elsevier BV
Date: 11-2017
Publisher: Informa UK Limited
Date: 2012
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 05-2020
Publisher: IOP Publishing
Date: 09-07-2015
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 2021
DOI: 10.2139/SSRN.3967517
Publisher: Elsevier BV
Date: 07-2004
Publisher: American Concrete Institute
Date: 07-2022
DOI: 10.14359/51734688
Publisher: American Society of Civil Engineers (ASCE)
Date: 09-2023
Publisher: American Concrete Institute
Date: 09-2021
DOI: 10.14359/51732823
Publisher: SAGE Publications
Date: 12-10-2023
Publisher: Elsevier BV
Date: 08-2023
Publisher: Elsevier BV
Date: 04-2022
Publisher: Informa UK Limited
Date: 10-08-1987
Publisher: Springer Science and Business Media LLC
Date: 23-12-2010
Publisher: Informa UK Limited
Date: 03-07-2017
Publisher: Springer Science and Business Media LLC
Date: 21-02-2020
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 1988
DOI: 10.1039/F29888401555
Publisher: Elsevier BV
Date: 02-2018
Publisher: American Concrete Institute
Date: 03-2018
DOI: 10.14359/51701238
Publisher: Elsevier BV
Date: 07-2021
Publisher: Informa UK Limited
Date: 29-12-2017
Publisher: Elsevier BV
Date: 02-2022
Publisher: Informa UK Limited
Date: 17-09-2019
Publisher: Springer Singapore
Date: 19-09-2020
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4409271
Publisher: Springer Science and Business Media LLC
Date: 11-01-2016
Publisher: Elsevier BV
Date: 06-2021
Publisher: American Society of Civil Engineers (ASCE)
Date: 09-2020
Publisher: Informa UK Limited
Date: 11-03-2022
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.SCITOTENV.2022.152936
Abstract: Heavy metals are one of the major chemical pollutant groups in urban runoff. The application of porous concrete is a potential alternative to conventional runoff management systems with the ability to remove heavy metals. Hence, a thorough understanding of the heavy metal removal mechanisms and constraints of conventional porous concrete opens a path for the development of effective modifications. This review critically discusses the major contributors in ordinary porous concrete which supports heavy metal removal. The effects of initial concentration, contact time and competing ions on heavy metal removal using porous concrete are also discussed. Additionally, the effect of decalcification, atmospheric carbonation, acid influent on heavy metal removal is reviewed. The major drawback of porous concrete is the high pH (>8.5) of the effluent water, decalcification of the porous concrete and leaching of adsorbed pollutants. Overall, the addition of adsorbent materials to the porous concrete increases removal efficiencies (7% - 65% increase) without neutralizing the effluent pH. Meanwhile, the addition of Reduced Graphene Oxide is successful in reducing the leachability of the removed heavy metals. The addition of pozzolanic materials can lower the effluent pH while maintaining similar removal efficiencies to unmodified porous concrete. Therefore, developing a novel method of neutralizing the effluent pH must be prioritized in future studies. Additionally, the toxicity that can occur due to the abrasion of modified porous concrete requires study in future research. Further, advanced characterization methods should be used in future studies to understand the mechanisms of removal via the modified porous concrete materials.
Publisher: Elsevier BV
Date: 07-2023
Publisher: American Concrete Institute
Date: 2019
DOI: 10.14359/51706941
Publisher: Trans Tech Publications, Ltd.
Date: 2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.841.104
Abstract: This paper reports on experimental work that has been undertaken to investigate the flexural strength performance of fly ash-based geopolymer (FG) concrete. The FG concrete was prepared using low calcium class F fly ash with high silicate content. The flexural strength properties of FG were assessed using modulus of rupture test up to the age of 360 days. Compressive strength and Ultrasonic Pulse Velocity (UPV) tests were also performed to corroborate the flexural strength test results. The results showed that the FG concrete demonstrates a comparable compressive strength and velocity to OPC concrete. Hewever, the flexural strength of FG concrete exhibited a better performance compared to that OPC concrete. The measured flexural strength of FG concrete also exhibited a higher value compared to the predicted one using ACI 318M-08 standard. The relationship between flexural strength with compressive strength demonstrated a similarity behavior to that OPC concrete. Thus, it can be concluded that the use of the ACI standard can be applied conservatively to determine the flexural strength of fly ash-based geopolymer concrete.
Publisher: Elsevier BV
Date: 10-2015
Publisher: Elsevier BV
Date: 07-2017
Publisher: American Society of Civil Engineers (ASCE)
Date: 09-2017
Publisher: Springer Science and Business Media LLC
Date: 10-05-2016
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 12-2016
End Date: 12-2023
Amount: $5,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2021
End Date: 07-2026
Amount: $5,000,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2008
End Date: 07-2013
Amount: $153,762.00
Funder: Australian Research Council
View Funded Activity