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Lamya Amleh

Toronto Metropolitan University, Civil Engineering Departement, Faculty Member

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Address: Toronto, Ontario, Canada

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Hacettepe University

Iolanda Craifaleanu

Technical University Of Civil Engineering, Bucharest

Technische Universität Dresden

Flavio Stochino

University of Cagliari

OLUYEMI DARAMOLA, PhD

Federal University of Technology Akure

Politehnica University of Timisoara

Kiran K U M A R Kudumula

ERITREA INSTITUTE OF TECHNOLOGY,MAI NEFHI,ERITREA

Future University ,Egypt.

University of Technology/Iraq

Wolfram Fürbeth

RWTH Aachen University

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Papers by Lamya Amleh

Risk Assessment Protocol for Existing Bridge Infrastructure Considering Climate Change

The escalating impact of climate change on global weather patterns threatens the functionality an... more The escalating impact of climate change on global weather patterns threatens the functionality and resilience of infrastructure systems. This paper presents a rigorous risk assessment protocol tailored to existing bridge infrastructure, integrating climate change projections, structural integrity, and socio-economic factors. The protocol's application involves five sequential steps: selecting a bridge, disassembling the structure into components, calculating utilization factors for design and projected temperatures, evaluating severity factors encompassing structural and socio-economic aspects, and ultimately determining an overall risk rating. To demonstrate the protocol's effectiveness, a case study is conducted on the Westminster Drive Underpass in London, Ontario. This study displays how the protocol systematically evaluates the vulnerability of each bridge component to projected temperatures under the Representative Concentration Pathway 6.0 model. The protocol provides...

The effect of climate change combined with clogged joints on bridge integrity in Canada

Canadian Journal of Civil Engineering

This study examines the impact of climate change combined with clogged expansion joints on the in... more This study examines the impact of climate change combined with clogged expansion joints on the integrity of four typical I- and box-girder bridges in Canada. The investigation considers 10 different climate regions across the country. The results reveal that the accumulation of debris, including compacted ice in expansion joints, poses a significant threat to bridge structures. Winnipeg and Saskatoon are identified as the most vulnerable regions to projected temperature changes with restricted movement, while Vancouver shows the lowest susceptibility. The study recommends classifying climate regions based on their vulnerability to climate change to facilitate resource allocation for bridge maintenance, rehabilitation, and replacement. Furthermore, a formula is introduced to assess and prioritize critical bridges in Canada’s extensive inventory, offering a systematic and objective approach to efficient resource allocation for bridge maintenance, repair, and rehabilitation.

Civil Engineering Education and Sustainable Infrastructure

A Framework for Durability Design and Bond Deterioration Due to Corrosion

Proceedings of the International Symposium dedicated to Professor Surendra Shah, Northwestern University, USA held on 3–4 September 2003 at the University of Dundee, Scotland, UK, 2003

This paper summarizes the current understanding of the mechanics of bond resistance at the interf... more This paper summarizes the current understanding of the mechanics of bond resistance at the interface between the concrete and plain and deformed steel bars and how it is influenced by the corrosion of the steel reinforcing bars. Some of the available research on analytical models for bond in uncorroded and corroded steel bars is reviewed. The influence of some of the significant parameters influencing the behavior of corroded steel rebars, such as the concrete strength, crack width, extent of rebar corrosion (measured by the mass loss of the cross-sectional area loss), concrete cover thickness, bar diameter and the loss of rebar lugs reported in some recent papers are summarily presented. Based on the overall trends observed, a preliminary design method for durability against deterioration of bond at the steel-concrete interface due to corrosion of rebars is proposed. The need for more research on these and other parameters influencing the phenomenon is stressed before a more reliable design method developed using a semi-probabilistic approach can be developed.

Bond Deterioration of Reinforcing Steel in Concrete Due to Corrosion

Proceedings of the International Seminar held at the University of Dundee, Scotland, UK on 5–6 September 2002, 2002

has been reproduced tram the microfilm master. UMI films the text directly tram the original or c... more has been reproduced tram the microfilm master. UMI films the text directly tram the original or copy submitted. Thus, sorne thesis and dissertation copies are in typewriter face, while others may be trom any type of computer printer. The quality of this reproduction is dependent upon the quallty of the copY submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. ln the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing trom left to right in equal sections with small overlaps.

Effect of different cement content and water cement ratio on carbonation depth and probability of carbonation induced corrosion for concrete

Cement Wapno Beton

Nowadays transportation infrastructure is subjected to a high percentage of carbon dioxide emissi... more Nowadays transportation infrastructure is subjected to a high percentage of carbon dioxide emissions. CO 2 greatly affects the carbonation depth of concrete, which can affect the deck for reinforced concrete bridges causing corrosion to steel reinforcement. Cement content and water to cement ratio greatly influence the carbonation depth of concrete. This study aims to investigate the effect of climate change on carbonation depth by considering different Representative Concentration Pathways [RCPs]. In addition, the effect of different compressive strengths on the carbonation depth was investigated in this research. Additionally, the effect of different cement contents on the probability of carbonation-induced corrosion has been investigated. Two parameters are considered, namely, the cement content 400 kg/m3, 350 kg/m3, and 250 kg/m3 and, the water to cement ratio [0.45 and 0.55]. This study RCPs for CO2 concentrations. The RCP [2.6, 4.5, 6, and 8.5] trajectory was used by the Inter...

Great-Expectations: The Strength of Canadian Bridge Infrastructure and the threat of Climate Change

Proceedings of the 3rd International Conference on Civil, Structural and Transportation Engineering (ICCSTE'18), Jun 1, 2018

Durability Field Investigation of an Abandoned Concrete Bridge

Challenges of Concrete Construction: Volume 5, Sustainable Concrete Construction, 2002

A summary of a detailed field and laboratory investigation, consisting of over 12000 different el... more A summary of a detailed field and laboratory investigation, consisting of over 12000 different electrochemical, chemical, physical and mechanical tests undertaken on the abandoned Dickson Bridge in Montreal, is presented. Constructed in 1959, this bridge was abandoned in 1993, after the ]1990-92 inspection showed severe delamination, and low air and high chloride contents significantly different from the acceptable threshold levels. Six industrial partners (Corrpro, Inc, PJ Consultants Ltd, SIKA Canada Ltd, SIREM Inc, the City of Montreal and Geo-Centers Inc.) and Queen's University of Belfast, Northern Ireland were involved in the project. The univariate analysis of the results showed considerable scatter, while multivariate analyses (not reported here) correlated the results from the various tests to determine the significance of the various parameters, which caused extensive early deterioration of the bridge. Besides being beneficial to the practising engineers in planning economic condition surveys, the related data bank and the statistics are being used presently to develop a reliability-based method of design for durability against corrosion of the reinforcing steel. (A) For the covering abstract see ITRD E121772.

Structural behavior of ultra high performance concrete beams subjected to bending

Engineering Structures, 2010

Ultra high performance concrete (UHPC) exhibits improved performance compared to conventional con... more Ultra high performance concrete (UHPC) exhibits improved performance compared to conventional concrete. Various experimental tests on structural behavior are of importance in order to establish reasonable design specifications for UHPC. Therefore, this study provides a detailed presentation of experimental test results for the flexural behavior of ultra high performance concrete beams. The experimental parameters included the amount of rebar and the placing method for the UHPC. The flexural behavioral characteristics were examined with respect to test results on UHPC beams with rebar ratios less than 0.02 and steel fibers with a volumetric ratio of 2%. Steel fiber-reinforced UHPC proves to be effective at controlling cracks and exhibits ductile behavior with a ductility index ranging between 1.60 and 3.75. In addition, the method of placing UHPC affects the flexural behavior with regard to the orientation of the steel fibers. The results of this study provide valuable data that can be used in future studies on the development of computational models of the deflection and flexural behavior of UHPC.

Corrosion Influence on Bond between Steel and Concrete

ACI Structural Journal, 1999

Abstract: The influence of corrosion on bond between the reinforcing steel and concrete was studi... more

MAT-763: Assessment of Ultra-High Performance Fibre Reinforced Concrete- Normal Strength Concrete or High Strength Concrete Composite Members in Chloride Environment

The purpose of this study was to investigate the performance of composite members of ultra-high p... more The purpose of this study was to investigate the performance of composite members of ultra-high performance fibrereinforced concrete (UHPFRC) and normal strength or high strength concrete (NSC/HSC) in chloride environments. Experimental studies were carried out on UHPFRC-NSC/HSC prisms in order to investigate the effect of dry and wet cycles on the flexural capacity of those composite members. Each prism specimen was designed with the UHPFRC layer in tension and the NSC/HSC layer in compression. Three fibre volume contents (1%, 1.5%, and 2%) were investigated. The test results revealed that the degradation in the flexural capacity of UHPFRC-NSC/HSC specimens after exposure to chloride ion solutions was between 4% and 17%. The results also revealed that the effect of using high strength concrete versus normal strength concrete in the composite prisms was negligible. In addition, the results revealed that the degradation in flexural capacity was reduced by an increase in the fibre vol...

Residual Flexural Strength of Corroded Reinforced Concrete Beams

Corrosion of reinforcing steel is one of the most deterioration factors that influence reinforced... more Corrosion of reinforcing steel is one of the most deterioration factors that influence reinforced concrete structures. Corrosion causes cracking and spalling of concrete structures, and reduces the bond strength at steel-concrete interface, and other related effects that weaken the serviceability and the ultimate strength of the reinforced concrete members. In this paper, a simple model that can be used to predict the residual flexural strength of RC beams with varying degrees of reinforcement corrosion based on experimental results using ANalysis Of VAriance (ANOVA). The moment resistance method which is based on flexural analysis of reinforced concrete beams was adopted. The results of the proposed model were validated by comparing the model with experimental results obtained by several researchers. The new proposed model in this study was able to successfully predict the residual flexural strength of corroded reinforced concrete beams.

Effect of severe chloride environment on the flexural behaviour of hybrid concrete systems

Magazine of Concrete Research, 2019

This paper reports an investigation into the effect of a severe chloride environment on the flexu... more This paper reports an investigation into the effect of a severe chloride environment on the flexural behaviour and microstructure of concrete composites combining normal- or high-strength concrete and ultra-high-performance fibre-reinforced concrete (UHPFRC). The normal- or high-strength concrete layers were used in the compression area while the UHPFRC, with three different fibre contents (1, 1·5 and 2%), was in tension. The goal was to measure the degradation of the bonding area and to investigate possible physical debonding under long-term exposure to a severe chloride environment. The microstructural properties of the degraded bond zone were examined by scanning electron microscopy, energy dispersive X-ray spectroscopy and backscattered electron imaging after 600 d of cycling exposure. The test results revealed that severe chloride exposure influenced the flexural capacity of the concrete composites. However, the bond between the normal- or high-strength concrete and UHPFRC laye...

Size effect of ultra-high performance fiber reinforced concrete composite beams in shear

Structural Concrete, 2018

In this paper, a finite element model (FEM) based on a concrete damage-plasticity approach was de... more In this paper, a finite element model (FEM) based on a concrete damage-plasticity approach was developed to investigate the size effect of ultra-high performance fiber reinforced concrete (UHPFRC) and normal-strength concrete or high-strength concrete (NSC/HSC) composite beams. The material behavior of UHPFRC was modeled by introducing a suitable tension stiffening model to simulate the behavior of UHPFRC beams in tension. Specimens containing UHPFRC with different fiber volume content that have an overall height between 300 and 1,200 mm, a constant shear span-effective depth ratio of 3 and no stirrups were investigated. The validity of the proposed model was established through comparisons between the experimental test results and those obtained in other studies. The results revealed that the size effect of UHPFRC members was diminished for fiber volume content higher than 1.5% due to the high ductility of UHPFRC material.

Physical and Chemical Actions of Nano-Mineral Additives on Properties of High-Volume Fly Ash Engineered Cementitious Composites

ACI Materials Journal, 2016

Self-healing capability of large-scale engineered cementitious composites beams

Composites Part B: Engineering, 2016

Engineered Cementitious Composites (ECC) is a material which possesses advanced selfhealing prope... more Engineered Cementitious Composites (ECC) is a material which possesses advanced selfhealing properties. Although the self-healing performance of ECC has been revealed in numerous studies, only small-scale, laboratory-size specimens have been used to assess it under fixed laboratory conditions and curing techniques. In order to evaluate the effect of intrinsic self-healing ability of ECC on the properties of structural-size, large-scale reinforced-beam members, specimens with four different shear span to effective depth (a/d) ratios, ranging from 1 to 4, were prepared to evaluate the effects of shear and flexural deformation. To ensure a realistic assessment, beams were cured using wet burlap, similar to on-site curing. Each beam was tested for mechanical properties including load-carrying capacity, deflection capacity, ductility ratio, yield stiffness, energy absorption capacity, and the influence of self-healing, by comparing types of failure and cracking. Self-healed test beams showed higher strength, energy absorption capacity and ductility ratio than damaged test beams. In test beams with an a/d ratio of 4 in which flexural behavior was prominent, self-healing application was highly successful; the strength, energy absorption capacity and ductility ratios of these beams achieved the level of undamaged beams. In addition, flexural cracks healed better, helping recover the properties of beams with predominantly flexural cracks rather than shear cracks.

Analytical modelling of bond stress at steel concrete interface due to corrosion

Structural Concrete, 2016

Author's Declaration I hereby declare that I am the sole author of this thesis or dissertation. I... more

The Effect of Implementing Project-Based Learning on Improving First-Year Engineering Student Learning Outcomes and Experience

ICERI2018 Proceedings, 2018

Sustanable Infrastructure and Civil Engineering Education

This paper reviews the role of civil engineers in design, construction, and management of infrast... more This paper reviews the role of civil engineers in design, construction, and management of infrastructure for safety, economy and efficiency. Because of lack of timely repair and rehabilitation, and unsustainable practice the infrastructure has deteriorated considerably, leading to a large infrastructure deficit of well over $100 billion. In addition, the degradation of the environment the impact of sustainable development on the environment and engineering practice is reviewed, along with the role of engineers and civil engineering education. Possible techniques to reorient civil engineering education to ameliorate the present unacceptable situation are proposed.

Effect of very severe sulfate environment on bonded composite concrete system

Construction and Building Materials

Abstract This paper deals with the physical, mechanical and microstructural performance of compos... more Abstract This paper deals with the physical, mechanical and microstructural performance of composite concrete system (CCS) in a very severe sulfate environment. The CCS was prepared with normal concrete (NC) layer to be tested in compression and ultra-high-performance fiber reinforced concrete (UHPFRC) with 0%, 1%, 1.5%, and 2% fiber volume contents to be tested in tension. The objective was to inspect the degradation level of the bonding area when assuring the absence of any form of debonding under repetitive cycles of immersion in a concentrated sodium sulfate solution and drying in an oven at high temperature (80 °C). Flexural properties, compressive strength and change in mass of the composite system were considered at different immersion-drying cycles. The form and concentration of the corrosion products were investigated at the microstructural level using the sulfate profile and the phase assemblage methods with SEM-EDS and backscattered electron imaging. The results show that, the compressive and flexural strengths of CCS decreased considerably after the long term exposure to very severe sulfate attack. However, the physical and mechanical resistance of CCS improved with increased fiber content, and the bonding area was maintained without mechanical degradation. The microstructural investigations confirmed the presence of high amount of reaction products in NC layer and a limited zone of UHPFRC, mainly around fibers close to the bond area.

Risk Assessment Protocol for Existing Bridge Infrastructure Considering Climate Change

The escalating impact of climate change on global weather patterns threatens the functionality an... more The escalating impact of climate change on global weather patterns threatens the functionality and resilience of infrastructure systems. This paper presents a rigorous risk assessment protocol tailored to existing bridge infrastructure, integrating climate change projections, structural integrity, and socio-economic factors. The protocol's application involves five sequential steps: selecting a bridge, disassembling the structure into components, calculating utilization factors for design and projected temperatures, evaluating severity factors encompassing structural and socio-economic aspects, and ultimately determining an overall risk rating. To demonstrate the protocol's effectiveness, a case study is conducted on the Westminster Drive Underpass in London, Ontario. This study displays how the protocol systematically evaluates the vulnerability of each bridge component to projected temperatures under the Representative Concentration Pathway 6.0 model. The protocol provides...

The effect of climate change combined with clogged joints on bridge integrity in Canada

Canadian Journal of Civil Engineering

This study examines the impact of climate change combined with clogged expansion joints on the in... more This study examines the impact of climate change combined with clogged expansion joints on the integrity of four typical I- and box-girder bridges in Canada. The investigation considers 10 different climate regions across the country. The results reveal that the accumulation of debris, including compacted ice in expansion joints, poses a significant threat to bridge structures. Winnipeg and Saskatoon are identified as the most vulnerable regions to projected temperature changes with restricted movement, while Vancouver shows the lowest susceptibility. The study recommends classifying climate regions based on their vulnerability to climate change to facilitate resource allocation for bridge maintenance, rehabilitation, and replacement. Furthermore, a formula is introduced to assess and prioritize critical bridges in Canada’s extensive inventory, offering a systematic and objective approach to efficient resource allocation for bridge maintenance, repair, and rehabilitation.

Civil Engineering Education and Sustainable Infrastructure

A Framework for Durability Design and Bond Deterioration Due to Corrosion

Proceedings of the International Symposium dedicated to Professor Surendra Shah, Northwestern University, USA held on 3–4 September 2003 at the University of Dundee, Scotland, UK, 2003

This paper summarizes the current understanding of the mechanics of bond resistance at the interf... more This paper summarizes the current understanding of the mechanics of bond resistance at the interface between the concrete and plain and deformed steel bars and how it is influenced by the corrosion of the steel reinforcing bars. Some of the available research on analytical models for bond in uncorroded and corroded steel bars is reviewed. The influence of some of the significant parameters influencing the behavior of corroded steel rebars, such as the concrete strength, crack width, extent of rebar corrosion (measured by the mass loss of the cross-sectional area loss), concrete cover thickness, bar diameter and the loss of rebar lugs reported in some recent papers are summarily presented. Based on the overall trends observed, a preliminary design method for durability against deterioration of bond at the steel-concrete interface due to corrosion of rebars is proposed. The need for more research on these and other parameters influencing the phenomenon is stressed before a more reliable design method developed using a semi-probabilistic approach can be developed.

Bond Deterioration of Reinforcing Steel in Concrete Due to Corrosion

Proceedings of the International Seminar held at the University of Dundee, Scotland, UK on 5–6 September 2002, 2002

has been reproduced tram the microfilm master. UMI films the text directly tram the original or c... more has been reproduced tram the microfilm master. UMI films the text directly tram the original or copy submitted. Thus, sorne thesis and dissertation copies are in typewriter face, while others may be trom any type of computer printer. The quality of this reproduction is dependent upon the quallty of the copY submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. ln the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing trom left to right in equal sections with small overlaps.

Effect of different cement content and water cement ratio on carbonation depth and probability of carbonation induced corrosion for concrete

Cement Wapno Beton

Nowadays transportation infrastructure is subjected to a high percentage of carbon dioxide emissi... more Nowadays transportation infrastructure is subjected to a high percentage of carbon dioxide emissions. CO 2 greatly affects the carbonation depth of concrete, which can affect the deck for reinforced concrete bridges causing corrosion to steel reinforcement. Cement content and water to cement ratio greatly influence the carbonation depth of concrete. This study aims to investigate the effect of climate change on carbonation depth by considering different Representative Concentration Pathways [RCPs]. In addition, the effect of different compressive strengths on the carbonation depth was investigated in this research. Additionally, the effect of different cement contents on the probability of carbonation-induced corrosion has been investigated. Two parameters are considered, namely, the cement content 400 kg/m3, 350 kg/m3, and 250 kg/m3 and, the water to cement ratio [0.45 and 0.55]. This study RCPs for CO2 concentrations. The RCP [2.6, 4.5, 6, and 8.5] trajectory was used by the Inter...

Great-Expectations: The Strength of Canadian Bridge Infrastructure and the threat of Climate Change

Proceedings of the 3rd International Conference on Civil, Structural and Transportation Engineering (ICCSTE'18), Jun 1, 2018

Durability Field Investigation of an Abandoned Concrete Bridge

Challenges of Concrete Construction: Volume 5, Sustainable Concrete Construction, 2002

A summary of a detailed field and laboratory investigation, consisting of over 12000 different el... more A summary of a detailed field and laboratory investigation, consisting of over 12000 different electrochemical, chemical, physical and mechanical tests undertaken on the abandoned Dickson Bridge in Montreal, is presented. Constructed in 1959, this bridge was abandoned in 1993, after the ]1990-92 inspection showed severe delamination, and low air and high chloride contents significantly different from the acceptable threshold levels. Six industrial partners (Corrpro, Inc, PJ Consultants Ltd, SIKA Canada Ltd, SIREM Inc, the City of Montreal and Geo-Centers Inc.) and Queen's University of Belfast, Northern Ireland were involved in the project. The univariate analysis of the results showed considerable scatter, while multivariate analyses (not reported here) correlated the results from the various tests to determine the significance of the various parameters, which caused extensive early deterioration of the bridge. Besides being beneficial to the practising engineers in planning economic condition surveys, the related data bank and the statistics are being used presently to develop a reliability-based method of design for durability against corrosion of the reinforcing steel. (A) For the covering abstract see ITRD E121772.

Structural behavior of ultra high performance concrete beams subjected to bending

Engineering Structures, 2010

Ultra high performance concrete (UHPC) exhibits improved performance compared to conventional con... more Ultra high performance concrete (UHPC) exhibits improved performance compared to conventional concrete. Various experimental tests on structural behavior are of importance in order to establish reasonable design specifications for UHPC. Therefore, this study provides a detailed presentation of experimental test results for the flexural behavior of ultra high performance concrete beams. The experimental parameters included the amount of rebar and the placing method for the UHPC. The flexural behavioral characteristics were examined with respect to test results on UHPC beams with rebar ratios less than 0.02 and steel fibers with a volumetric ratio of 2%. Steel fiber-reinforced UHPC proves to be effective at controlling cracks and exhibits ductile behavior with a ductility index ranging between 1.60 and 3.75. In addition, the method of placing UHPC affects the flexural behavior with regard to the orientation of the steel fibers. The results of this study provide valuable data that can be used in future studies on the development of computational models of the deflection and flexural behavior of UHPC.

Corrosion Influence on Bond between Steel and Concrete

ACI Structural Journal, 1999

Abstract: The influence of corrosion on bond between the reinforcing steel and concrete was studi... more

MAT-763: Assessment of Ultra-High Performance Fibre Reinforced Concrete- Normal Strength Concrete or High Strength Concrete Composite Members in Chloride Environment

The purpose of this study was to investigate the performance of composite members of ultra-high p... more The purpose of this study was to investigate the performance of composite members of ultra-high performance fibrereinforced concrete (UHPFRC) and normal strength or high strength concrete (NSC/HSC) in chloride environments. Experimental studies were carried out on UHPFRC-NSC/HSC prisms in order to investigate the effect of dry and wet cycles on the flexural capacity of those composite members. Each prism specimen was designed with the UHPFRC layer in tension and the NSC/HSC layer in compression. Three fibre volume contents (1%, 1.5%, and 2%) were investigated. The test results revealed that the degradation in the flexural capacity of UHPFRC-NSC/HSC specimens after exposure to chloride ion solutions was between 4% and 17%. The results also revealed that the effect of using high strength concrete versus normal strength concrete in the composite prisms was negligible. In addition, the results revealed that the degradation in flexural capacity was reduced by an increase in the fibre vol...

Residual Flexural Strength of Corroded Reinforced Concrete Beams

Corrosion of reinforcing steel is one of the most deterioration factors that influence reinforced... more Corrosion of reinforcing steel is one of the most deterioration factors that influence reinforced concrete structures. Corrosion causes cracking and spalling of concrete structures, and reduces the bond strength at steel-concrete interface, and other related effects that weaken the serviceability and the ultimate strength of the reinforced concrete members. In this paper, a simple model that can be used to predict the residual flexural strength of RC beams with varying degrees of reinforcement corrosion based on experimental results using ANalysis Of VAriance (ANOVA). The moment resistance method which is based on flexural analysis of reinforced concrete beams was adopted. The results of the proposed model were validated by comparing the model with experimental results obtained by several researchers. The new proposed model in this study was able to successfully predict the residual flexural strength of corroded reinforced concrete beams.

Effect of severe chloride environment on the flexural behaviour of hybrid concrete systems

Magazine of Concrete Research, 2019

This paper reports an investigation into the effect of a severe chloride environment on the flexu... more This paper reports an investigation into the effect of a severe chloride environment on the flexural behaviour and microstructure of concrete composites combining normal- or high-strength concrete and ultra-high-performance fibre-reinforced concrete (UHPFRC). The normal- or high-strength concrete layers were used in the compression area while the UHPFRC, with three different fibre contents (1, 1·5 and 2%), was in tension. The goal was to measure the degradation of the bonding area and to investigate possible physical debonding under long-term exposure to a severe chloride environment. The microstructural properties of the degraded bond zone were examined by scanning electron microscopy, energy dispersive X-ray spectroscopy and backscattered electron imaging after 600 d of cycling exposure. The test results revealed that severe chloride exposure influenced the flexural capacity of the concrete composites. However, the bond between the normal- or high-strength concrete and UHPFRC laye...

Size effect of ultra-high performance fiber reinforced concrete composite beams in shear

Structural Concrete, 2018

In this paper, a finite element model (FEM) based on a concrete damage-plasticity approach was de... more In this paper, a finite element model (FEM) based on a concrete damage-plasticity approach was developed to investigate the size effect of ultra-high performance fiber reinforced concrete (UHPFRC) and normal-strength concrete or high-strength concrete (NSC/HSC) composite beams. The material behavior of UHPFRC was modeled by introducing a suitable tension stiffening model to simulate the behavior of UHPFRC beams in tension. Specimens containing UHPFRC with different fiber volume content that have an overall height between 300 and 1,200 mm, a constant shear span-effective depth ratio of 3 and no stirrups were investigated. The validity of the proposed model was established through comparisons between the experimental test results and those obtained in other studies. The results revealed that the size effect of UHPFRC members was diminished for fiber volume content higher than 1.5% due to the high ductility of UHPFRC material.

Physical and Chemical Actions of Nano-Mineral Additives on Properties of High-Volume Fly Ash Engineered Cementitious Composites

ACI Materials Journal, 2016

Self-healing capability of large-scale engineered cementitious composites beams

Composites Part B: Engineering, 2016

Engineered Cementitious Composites (ECC) is a material which possesses advanced selfhealing prope... more Engineered Cementitious Composites (ECC) is a material which possesses advanced selfhealing properties. Although the self-healing performance of ECC has been revealed in numerous studies, only small-scale, laboratory-size specimens have been used to assess it under fixed laboratory conditions and curing techniques. In order to evaluate the effect of intrinsic self-healing ability of ECC on the properties of structural-size, large-scale reinforced-beam members, specimens with four different shear span to effective depth (a/d) ratios, ranging from 1 to 4, were prepared to evaluate the effects of shear and flexural deformation. To ensure a realistic assessment, beams were cured using wet burlap, similar to on-site curing. Each beam was tested for mechanical properties including load-carrying capacity, deflection capacity, ductility ratio, yield stiffness, energy absorption capacity, and the influence of self-healing, by comparing types of failure and cracking. Self-healed test beams showed higher strength, energy absorption capacity and ductility ratio than damaged test beams. In test beams with an a/d ratio of 4 in which flexural behavior was prominent, self-healing application was highly successful; the strength, energy absorption capacity and ductility ratios of these beams achieved the level of undamaged beams. In addition, flexural cracks healed better, helping recover the properties of beams with predominantly flexural cracks rather than shear cracks.

Analytical modelling of bond stress at steel concrete interface due to corrosion

Structural Concrete, 2016

Author's Declaration I hereby declare that I am the sole author of this thesis or dissertation. I... more

The Effect of Implementing Project-Based Learning on Improving First-Year Engineering Student Learning Outcomes and Experience

ICERI2018 Proceedings, 2018

Sustanable Infrastructure and Civil Engineering Education

This paper reviews the role of civil engineers in design, construction, and management of infrast... more This paper reviews the role of civil engineers in design, construction, and management of infrastructure for safety, economy and efficiency. Because of lack of timely repair and rehabilitation, and unsustainable practice the infrastructure has deteriorated considerably, leading to a large infrastructure deficit of well over $100 billion. In addition, the degradation of the environment the impact of sustainable development on the environment and engineering practice is reviewed, along with the role of engineers and civil engineering education. Possible techniques to reorient civil engineering education to ameliorate the present unacceptable situation are proposed.

Effect of very severe sulfate environment on bonded composite concrete system

Construction and Building Materials

Abstract This paper deals with the physical, mechanical and microstructural performance of compos... more Abstract This paper deals with the physical, mechanical and microstructural performance of composite concrete system (CCS) in a very severe sulfate environment. The CCS was prepared with normal concrete (NC) layer to be tested in compression and ultra-high-performance fiber reinforced concrete (UHPFRC) with 0%, 1%, 1.5%, and 2% fiber volume contents to be tested in tension. The objective was to inspect the degradation level of the bonding area when assuring the absence of any form of debonding under repetitive cycles of immersion in a concentrated sodium sulfate solution and drying in an oven at high temperature (80 °C). Flexural properties, compressive strength and change in mass of the composite system were considered at different immersion-drying cycles. The form and concentration of the corrosion products were investigated at the microstructural level using the sulfate profile and the phase assemblage methods with SEM-EDS and backscattered electron imaging. The results show that, the compressive and flexural strengths of CCS decreased considerably after the long term exposure to very severe sulfate attack. However, the physical and mechanical resistance of CCS improved with increased fiber content, and the bonding area was maintained without mechanical degradation. The microstructural investigations confirmed the presence of high amount of reaction products in NC layer and a limited zone of UHPFRC, mainly around fibers close to the bond area.