1.
Yanuar Haryanto; Fu-Pei Hsiao; Hsuan-Teh Hu; Ay Lie Han; Andre Wiranata Chu; Fernando Salim; Laurencius Nugroho
Structural behavior of negative moment region NSM-CFRP strengthened RC T-beams with various embedment depth under monotonic and cyclic loading Journal Article
In: Composite Structures, vol. 301, 2022, ISSN: 0263-8223.
@article{nokey,
title = {Structural behavior of negative moment region NSM-CFRP strengthened RC T-beams with various embedment depth under monotonic and cyclic loading},
author = {Yanuar Haryanto and Fu-Pei Hsiao and Hsuan-Teh Hu and Ay Lie Han and Andre Wiranata Chu and Fernando Salim and Laurencius Nugroho},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0263822322009461?via%3Dihub},
doi = {https://doi.org/10.1016/j.compstruct.2022.116214},
issn = {0263-8223},
year = {2022},
date = {2022-12-01},
journal = {Composite Structures},
volume = {301},
abstract = {Under cyclic loading circumstances, reinforced concrete (RC) constructions may be subject to failure. Because they may indicate inadequate capacity owing to aging, environmental effects, or unintentional impacts, strengthening is critical to resist static and cyclic loads. Therefore, the goal of this research was to look at how bare and negative moment region strengthened RC T-beams behaved under monotonic and low reversed cyclic loads. As the strengthening system, carbon fiber reinforced polymer (CFRP) rods having different embedment depths were used with a near-surface mounted (NSM) approach. The findings of this study demonstrated that the impact of NSM-CFRP rods was sufficient for extending the ultimate load and capturing cracks under monotonic loading. Additionally, as compared to their bare counterparts, the negative moment region NSM-CFRP strengthened beams showed improved hysteresis behavior, a larger energy dissipation capacity together with initial stiffness, and a reduced damage index under cyclic loading. Moreover, the experimentally determined load-carrying capacities matched reasonably well with the theoretical predictions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Under cyclic loading circumstances, reinforced concrete (RC) constructions may be subject to failure. Because they may indicate inadequate capacity owing to aging, environmental effects, or unintentional impacts, strengthening is critical to resist static and cyclic loads. Therefore, the goal of this research was to look at how bare and negative moment region strengthened RC T-beams behaved under monotonic and low reversed cyclic loads. As the strengthening system, carbon fiber reinforced polymer (CFRP) rods having different embedment depths were used with a near-surface mounted (NSM) approach. The findings of this study demonstrated that the impact of NSM-CFRP rods was sufficient for extending the ultimate load and capturing cracks under monotonic loading. Additionally, as compared to their bare counterparts, the negative moment region NSM-CFRP strengthened beams showed improved hysteresis behavior, a larger energy dissipation capacity together with initial stiffness, and a reduced damage index under cyclic loading. Moreover, the experimentally determined load-carrying capacities matched reasonably well with the theoretical predictions.
2.
Bagus Hario Setiadji; M Agung Wibowo; Henk M Jonkers; Marc Ottele; Widayat; Mochammad Qomaruddin; Felix Hariyanto Sugianto; Purwanto; Han Ay Lie
Pyrolysis of Reclaimed Asphalt Aggregates in Mortar Journal Article
In: International Journal of Technology (IJTech), vol. 13, no. 4, 2022.
@article{nokey,
title = {Pyrolysis of Reclaimed Asphalt Aggregates in Mortar},
author = {Bagus Hario Setiadji and M Agung Wibowo and Henk M Jonkers and Marc Ottele and Widayat and Mochammad Qomaruddin and Felix Hariyanto Sugianto and Purwanto and Han Ay Lie },
url = {https://ijtech.eng.ui.ac.id/article/view/5621},
doi = {https://doi.org/10.14716/ijtech.v13i4.5621},
year = {2022},
date = {2022-10-07},
journal = {International Journal of Technology (IJTech)},
volume = {13},
number = {4},
abstract = {Asphalt pavement consists of aggregates resulting in a waste material at end of its life. The aggregates can be reused as basic material for asphalt or cementitious binding agents. In both scenarios, the recycled aggregates should provide a good bond with the binder to achieve strength. This study focuses on reusing recycled asphalt aggregates (RAA) in mortar. The major weakness of RAA is the thin oily film originating from the asphalt residue, weakening the bond with cement. The pyrolysis method is accessed in an attempt to overcome this weakness. Three scenarios were investigated; the use of virgin aggregates (VA), RAA, and pyrolysis recycled asphalt aggregate (PRAA) as constituent in mortar. All variables were set a constant except for the aggregate type, the VA mortar function as controlling element. This research is methodologically based on experimental data conducted in the laboratory, while aggregate samples were taken from the field. To analyze the influence of pyrolysis to the aggregate-to-cement bond behaviour, qualitative and quantitative data were collected. The quantitative data were the mechanical properties, the mortar tensile, and compression strength. The qualitative data were obtained from scanning electron microscope readings to visually observe the aggregate surface roughness and voids, including the aggregates cross-section and pre-existing micro-cracks in the aggregate-to-cement interface. Supporting data were the aggregates‘ abrasion rate and absorption. The RAA resulted in a significant mortar strength decrease. This conclusion was supported by the findings of pre-existing cracks in the interfacial transition zone. The pyrolysis method improved the compression strength but negligibly affected the tensile behavior. The compression and tensile strength increased as a function of time for both RAA and PRAA, and a strength convergence was reached at 28 days. The PRAA is considered an option for reuse in mortar, supporting nature conservation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Asphalt pavement consists of aggregates resulting in a waste material at end of its life. The aggregates can be reused as basic material for asphalt or cementitious binding agents. In both scenarios, the recycled aggregates should provide a good bond with the binder to achieve strength. This study focuses on reusing recycled asphalt aggregates (RAA) in mortar. The major weakness of RAA is the thin oily film originating from the asphalt residue, weakening the bond with cement. The pyrolysis method is accessed in an attempt to overcome this weakness. Three scenarios were investigated; the use of virgin aggregates (VA), RAA, and pyrolysis recycled asphalt aggregate (PRAA) as constituent in mortar. All variables were set a constant except for the aggregate type, the VA mortar function as controlling element. This research is methodologically based on experimental data conducted in the laboratory, while aggregate samples were taken from the field. To analyze the influence of pyrolysis to the aggregate-to-cement bond behaviour, qualitative and quantitative data were collected. The quantitative data were the mechanical properties, the mortar tensile, and compression strength. The qualitative data were obtained from scanning electron microscope readings to visually observe the aggregate surface roughness and voids, including the aggregates cross-section and pre-existing micro-cracks in the aggregate-to-cement interface. Supporting data were the aggregates‘ abrasion rate and absorption. The RAA resulted in a significant mortar strength decrease. This conclusion was supported by the findings of pre-existing cracks in the interfacial transition zone. The pyrolysis method improved the compression strength but negligibly affected the tensile behavior. The compression and tensile strength increased as a function of time for both RAA and PRAA, and a strength convergence was reached at 28 days. The PRAA is considered an option for reuse in mortar, supporting nature conservation.
3.
Joko Purnomo; Aylie Han; Rito Yamakawa; Buntara S. Gan
Systematic calibration procedure for CFRP sheets and rods strengthened RC T-beams by using RBSM Journal Article
In: Mechanics of Advanced Materials and Structures , 2022.
@article{nokey,
title = {Systematic calibration procedure for CFRP sheets and rods strengthened RC T-beams by using RBSM},
author = {Joko Purnomo and Aylie Han and Rito Yamakawa and Buntara S. Gan},
url = {https://www.tandfonline.com/doi/full/10.1080/15376494.2022.2111483},
doi = {https://doi.org/10.1080/15376494.2022.2111483},
year = {2022},
date = {2022-08-22},
urldate = {2022-08-22},
journal = {Mechanics of Advanced Materials and Structures },
abstract = {In this study, a nonlinear 2D rigid body spring model (RBSM) was developed to verify the experimental works of Carbon Fiber Reinforced Polymer (CFRP) sheets and rods strengthened reinforced concrete (RC) T-shape beam (RC T-beam) section under a combination of bending and shearing loads. Modified Mohr–Coulomb criteria were adopted for modeling the plastic damage of concrete material. The orthotropic smeared layers representing the steel and CFRP materials were laminated on the concrete surface to model the reinforcing steel bars, stirrup steel, and CFRP sheets and rods. A mechanical behavior-based approach to fit the experimental results was discussed using the numerical results at each calibration stage. This study shows how the gradient of compressive and ultimate tensile strength of concrete affects the initial flexure behavior of the load-displacement curve of an RC T-beam. In contrast with finite element modeling, the RBSM can exhibit the crack propagation processes of element separation during the simulation. The calibrations showed the agreement of the models used in predicting the flexural behavior, ultimate load, and strengthening effects of the CFRP sheets and rods to the RC T-beam under bending loads. A systematic calibration procedure combined with the recommended use of energy-based criteria to evaluate the results of calibrated load-displacement curve was proposed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this study, a nonlinear 2D rigid body spring model (RBSM) was developed to verify the experimental works of Carbon Fiber Reinforced Polymer (CFRP) sheets and rods strengthened reinforced concrete (RC) T-shape beam (RC T-beam) section under a combination of bending and shearing loads. Modified Mohr–Coulomb criteria were adopted for modeling the plastic damage of concrete material. The orthotropic smeared layers representing the steel and CFRP materials were laminated on the concrete surface to model the reinforcing steel bars, stirrup steel, and CFRP sheets and rods. A mechanical behavior-based approach to fit the experimental results was discussed using the numerical results at each calibration stage. This study shows how the gradient of compressive and ultimate tensile strength of concrete affects the initial flexure behavior of the load-displacement curve of an RC T-beam. In contrast with finite element modeling, the RBSM can exhibit the crack propagation processes of element separation during the simulation. The calibrations showed the agreement of the models used in predicting the flexural behavior, ultimate load, and strengthening effects of the CFRP sheets and rods to the RC T-beam under bending loads. A systematic calibration procedure combined with the recommended use of energy-based criteria to evaluate the results of calibrated load-displacement curve was proposed.
4.
Nuroji; Ay Lie Han; Sri Tudjono; Lena Tri Lestari; Tiara Murtisari
A Proposed Method of FRP Anchorage for FRP Confined Over-Reinforced Concrete Beam Journal Article
In: ICRMCE 2021: Proceedings of the 5th International Conference on Rehabilitation and Maintenance in Civil Engineering , pp. 225–232, 2022.
@article{nokey,
title = { A Proposed Method of FRP Anchorage for FRP Confined Over-Reinforced Concrete Beam},
author = {Nuroji and Ay Lie Han and Sri Tudjono and Lena Tri Lestari and Tiara Murtisari },
url = {https://link.springer.com/chapter/10.1007/978-981-16-9348-9_20},
doi = {10.1007/978-981-16-9348-9_20},
year = {2022},
date = {2022-07-22},
journal = {ICRMCE 2021: Proceedings of the 5th International Conference on Rehabilitation and Maintenance in Civil Engineering },
pages = { 225–232},
abstract = {Fiber Reinforced Polymer (FRP) is a material for strengthening, retrofitting or confining concrete elements. Research on the FRP performance demonstrated that debonding was one of the major failure modes, reducing the ultimate capacity of the composite action between the FRP and concrete. Debonding between FRP and concrete is mostly characterized in the interfacial transition zone (ITZ). Increasing the bond performance in the ITZ is conducted by applying an anchorage system to prevent premature bond loss. The aim of this paper is to propose three concepts of FRP anchorage systems and evaluate their usefulness and theoretical effectiveness. For evaluation, an over-reinforced flexural member is externally strengthened using carbon fiber wraps, the compression area of this member is confined using a u-shape configuration. The three types of FRP anchorages introduced in this study are the spike, insertion, and stitch anchor. It is expected that the anchors will increase the bond performance between the concrete and the CFRP, preventing premature failure and increasing the concrete strength and deformation behavior due to the confinement effect. At further stages, full size elements will be tested to prove this hypothesis, and to evaluate which type of the three anchors is the most effective.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Fiber Reinforced Polymer (FRP) is a material for strengthening, retrofitting or confining concrete elements. Research on the FRP performance demonstrated that debonding was one of the major failure modes, reducing the ultimate capacity of the composite action between the FRP and concrete. Debonding between FRP and concrete is mostly characterized in the interfacial transition zone (ITZ). Increasing the bond performance in the ITZ is conducted by applying an anchorage system to prevent premature bond loss. The aim of this paper is to propose three concepts of FRP anchorage systems and evaluate their usefulness and theoretical effectiveness. For evaluation, an over-reinforced flexural member is externally strengthened using carbon fiber wraps, the compression area of this member is confined using a u-shape configuration. The three types of FRP anchorages introduced in this study are the spike, insertion, and stitch anchor. It is expected that the anchors will increase the bond performance between the concrete and the CFRP, preventing premature failure and increasing the concrete strength and deformation behavior due to the confinement effect. At further stages, full size elements will be tested to prove this hypothesis, and to evaluate which type of the three anchors is the most effective.
5.
Mochammad Qomaruddin; Han Ay Lie; Widayat; Bagus Hario Setiadji; Mochamad Agung Wibowo
Mapping Literature of Reclaimed Asphalt Pavement Using Bibliometric Analysis by VOSviewer Journal Article
In: ICRMCE 2021: Proceedings of the 5th International Conference on Rehabilitation and Maintenance in Civil Engineering, pp. 1085–1093, 2022.
@article{nokey,
title = {Mapping Literature of Reclaimed Asphalt Pavement Using Bibliometric Analysis by VOSviewer},
author = { Mochammad Qomaruddin and Han Ay Lie and Widayat and Bagus Hario Setiadji and Mochamad Agung Wibowo },
url = {https://link.springer.com/chapter/10.1007/978-981-16-9348-9_96},
doi = {10.1007/978-981-16-9348-9_96},
year = {2022},
date = {2022-07-19},
journal = {ICRMCE 2021: Proceedings of the 5th International Conference on Rehabilitation and Maintenance in Civil Engineering},
pages = {1085–1093},
abstract = {The purpose of this research is to map the literature on reclaimed asphalt pavement (RAP) and to determine future related potential topics. Data were collected from the Scopus meta-data and analyzed using the bibliometric analysis technique with the VOSviewer tool. The result showed that there are several relationships between RAP and the topics related to aggregate, mixing, hot-mix asphalt, and compressive strength. However, some topics such as extraction, microstructural properties, furnaces, and interfacial transition zone in the RAP have not been widely researched. Numerous studies have been carried out on RAP by authors such as Xiao F, Amirkhanian S N, Daniel J S, Canestrari F, Huang B, Zaumanis M, and Arulrajah. Some of the countries that have contributed significantly to RAP research are the United States of America, China, Italy, and India.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The purpose of this research is to map the literature on reclaimed asphalt pavement (RAP) and to determine future related potential topics. Data were collected from the Scopus meta-data and analyzed using the bibliometric analysis technique with the VOSviewer tool. The result showed that there are several relationships between RAP and the topics related to aggregate, mixing, hot-mix asphalt, and compressive strength. However, some topics such as extraction, microstructural properties, furnaces, and interfacial transition zone in the RAP have not been widely researched. Numerous studies have been carried out on RAP by authors such as Xiao F, Amirkhanian S N, Daniel J S, Canestrari F, Huang B, Zaumanis M, and Arulrajah. Some of the countries that have contributed significantly to RAP research are the United States of America, China, Italy, and India.
6.
Sukamta; Bagus Acung Billahi; Susilo Adi Widyanto; Han Ay Lie
Method Assessment of Bridge Conditions Using Vibration Mode Patterns Journal Article
In: Proceedings of the 5th International Conference on Sustainable Civil Engineering Structures and Construction Materials, pp. 787–801, 2022.
@article{nokey,
title = {Method Assessment of Bridge Conditions Using Vibration Mode Patterns},
author = {Sukamta and Bagus Acung Billahi and Susilo Adi Widyanto and Han Ay Lie },
url = {https://link.springer.com/chapter/10.1007/978-981-16-7924-7_51},
doi = {10.1007/978-981-16-7924-7_51},
year = {2022},
date = {2022-04-07},
journal = {Proceedings of the 5th International Conference on Sustainable Civil Engineering Structures and Construction Materials},
pages = {787–801},
abstract = {The current bridge structure maintenance method is done by visual observation only, this often has limitations and the results obtained are less accurate. This research was conducted to obtain a vibratory mode data base which will be used as a basis for compiling the failure patterns of the bridge structure. Vibration mode measurements are carried out on the prototype and the bridge model using an accelerometer sensor mounted on the bridge structure. Accelerometer installed at several points to get variations in the vibrate mode. Dynamic load frequency variations are given to get vibrational mode variations. The results of the vibration mode measurement analysis show the similarity between the prototype and the model, so that the bridge model can be used to study structural failure patterns.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The current bridge structure maintenance method is done by visual observation only, this often has limitations and the results obtained are less accurate. This research was conducted to obtain a vibratory mode data base which will be used as a basis for compiling the failure patterns of the bridge structure. Vibration mode measurements are carried out on the prototype and the bridge model using an accelerometer sensor mounted on the bridge structure. Accelerometer installed at several points to get variations in the vibrate mode. Dynamic load frequency variations are given to get vibrational mode variations. The results of the vibration mode measurement analysis show the similarity between the prototype and the model, so that the bridge model can be used to study structural failure patterns.
7.
Sukamta; Angga Alfiannur; Susilo Adi Widyanto; Han Ay Lie
Development Experimental Investigations of Truss Bridge Model for Vibration-Based Structural Health Monitoring Journal Article
In: Proceedings of the 5th International Conference on Sustainable Civil Engineering Structures and Construction Materials, pp. 137–153, 2022.
@article{nokey,
title = {Development Experimental Investigations of Truss Bridge Model for Vibration-Based Structural Health Monitoring},
author = {Sukamta and Angga Alfiannur and Susilo Adi Widyanto and Han Ay Lie },
url = {https://link.springer.com/chapter/10.1007/978-981-16-7924-7_9},
doi = {10.1007/978-981-16-7924-7_9},
year = {2022},
date = {2022-04-07},
journal = {Proceedings of the 5th International Conference on Sustainable Civil Engineering Structures and Construction Materials},
pages = {137–153},
abstract = {In recent years the need for Structural Health Monitoring (SHM) has become increasingly important. Given current technological developments, a visual inspection can no longer be a reference due to inaccurate accuracy levels. In this case, there is a need for an early warning in detecting fast and accurate damage compared to visual inspection. This study proposes a vibration-based structural health monitoring analytical framework by introducing a modal analysis approach based on the bridges structural response. The test begins with making a small-scale model of a steel frame type bridge using the similarity model theory to project a prototype bridge. In this research, a damage simulation is given to the model to project damage to the structure. Static and dynamic tests are carrying to obtain the response characteristics of the structure. The assessment has delayed consequences exhibit that the variety of the supported discharge shows that contrasts look like the bend of the predominant recurrence that influences the FFT bend. Output values in natural frequency, mode shapes, and capital damping ratios were adopted as damage indicators. As a comparison, we are testing the model using FE simulation with a tolerance level of 10%. This research is using to build an SHM database system of the existing bridge structure model.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In recent years the need for Structural Health Monitoring (SHM) has become increasingly important. Given current technological developments, a visual inspection can no longer be a reference due to inaccurate accuracy levels. In this case, there is a need for an early warning in detecting fast and accurate damage compared to visual inspection. This study proposes a vibration-based structural health monitoring analytical framework by introducing a modal analysis approach based on the bridges structural response. The test begins with making a small-scale model of a steel frame type bridge using the similarity model theory to project a prototype bridge. In this research, a damage simulation is given to the model to project damage to the structure. Static and dynamic tests are carrying to obtain the response characteristics of the structure. The assessment has delayed consequences exhibit that the variety of the supported discharge shows that contrasts look like the bend of the predominant recurrence that influences the FFT bend. Output values in natural frequency, mode shapes, and capital damping ratios were adopted as damage indicators. As a comparison, we are testing the model using FE simulation with a tolerance level of 10%. This research is using to build an SHM database system of the existing bridge structure model.
8.
Banu A Hidayat; Hsuan-Teh Hu; Fu-Pei Hsiao; Wen-Cheng Shen; Pu-Wen Weng; Ay Lie Han; Li-Yin Chan; Yanuar Haryanto
Modeling of non-ductile RC structure under near-fault ground motions: A nonlinear finite element analysis Journal Article
In: SAGE Journals, vol. 25, iss. 9, 2022.
@article{nokey,
title = {Modeling of non-ductile RC structure under near-fault ground motions: A nonlinear finite element analysis},
author = {Banu A Hidayat and Hsuan-Teh Hu and Fu-Pei Hsiao and Wen-Cheng Shen and Pu-Wen Weng and Ay Lie Han and Li-Yin Chan and Yanuar Haryanto},
url = {https://journals.sagepub.com/doi/abs/10.1177/13694332221080602?journalCode=asea},
doi = {https://doi.org/10.1177/136943322210806},
year = {2022},
date = {2022-03-25},
journal = { SAGE Journals},
volume = {25},
issue = {9},
abstract = {The old existing reinforced concrete (RC) structures in Taiwan are susceptible to severe damage under earthquakes because of the soft-story mechanism. Moreover, the effects of near-fault ground motions often contain a long period of velocity pulse and permanent ground displacement. This study is based on the tri-axial shaking table test conducted at the National Center for Research on Earthquake Engineering in Taiwan and a series of seismic performance evaluations of a non-ductile RC structure in Taiwan. Finite element analysis (FEA) will be conducted to simulate the linear and nonlinear behavior of the seven-story building. This accommodates the damage plasticity model for concrete and the elastic-perfectly plastic model for reinforcement. Comparison of the results between the experimental test and numerical model showed that the similarity of the vibration period has a great influence on the simulation results. The findings showed that the data of acceleration and displacement behavior corresponded with the experimental results in a satisfactory margin. Also, the damage mode is very similar to the shaking table test results. The study found that using FEA can satisfactorily simulate the seismic performance of mid-rise buildings under a near-fault earthquake.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The old existing reinforced concrete (RC) structures in Taiwan are susceptible to severe damage under earthquakes because of the soft-story mechanism. Moreover, the effects of near-fault ground motions often contain a long period of velocity pulse and permanent ground displacement. This study is based on the tri-axial shaking table test conducted at the National Center for Research on Earthquake Engineering in Taiwan and a series of seismic performance evaluations of a non-ductile RC structure in Taiwan. Finite element analysis (FEA) will be conducted to simulate the linear and nonlinear behavior of the seven-story building. This accommodates the damage plasticity model for concrete and the elastic-perfectly plastic model for reinforcement. Comparison of the results between the experimental test and numerical model showed that the similarity of the vibration period has a great influence on the simulation results. The findings showed that the data of acceleration and displacement behavior corresponded with the experimental results in a satisfactory margin. Also, the damage mode is very similar to the shaking table test results. The study found that using FEA can satisfactorily simulate the seismic performance of mid-rise buildings under a near-fault earthquake.
9.
Ay Lie Han; Hsuan-Teh Hu; Buntara S. Gan; Fu-Pei Hsiao; Yanuar Haryanto
Carbon Fiber-Reinforced Polymer Rod Embedment Depth Influence on Concrete Strengthening Journal Article
In: Arabian Journal for Science and Engineering, 2022.
@article{nokey,
title = {Carbon Fiber-Reinforced Polymer Rod Embedment Depth Influence on Concrete Strengthening},
author = {Ay Lie Han and Hsuan-Teh Hu and Buntara S. Gan and Fu-Pei Hsiao and Yanuar Haryanto},
url = {https://link.springer.com/article/10.1007/s13369-022-06601-2},
doi = {https://doi.org/10.1007/s13369-022-06601-2},
year = {2022},
date = {2022-02-04},
journal = {Arabian Journal for Science and Engineering},
abstract = {The use of carbon fiber-reinforced polymer (CFRP) rods offers a good solution for external strengthening of flexural reinforced concrete (RC) members. Limited data are available on the behavior of beams externally reinforced with CFRP rods under a loading–unloading protocol, which is of great importance for structural components subjected to vehicle loading. The embedment depth mandated by the majority of standards cannot always be acquired due to concrete cover limitations; the influence of embedment depth under this loading–unloading sequence needs to be investigated. This research studied the effects of rod embedment depth by comparing fully-embedded rods with half-embedded rods under a loading–unloading protocol and comparing the results with monotonic responses. An identical specimen without CFRP reinforcement functioned as the controlling element. The near-surface mounted technique (NSM) was used to integrate the rods with the concrete. The results show that CFRP rods positively affect the load-carrying capacity under a loading–unloading condition. The rods reduce the member’s ductility under monotonic loading but have no negative impact under loading–unloading. Whereas the difference in embedment depth configuration slightly affected the enhancement under monotonic loading, the half-embedded rods drastically reduced the capacity improvement under the loading–unloading sequence. An embedment depth deviating from the advised depth, should not be implemented for members subjected to a loading–unloading condition. The CFRP placement method had an impact on the failure behavior of the elements. The half-embedded rod failed by debonding between the rod and the epoxy resin, while the fully-embedded members were characterized by concrete spalling.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The use of carbon fiber-reinforced polymer (CFRP) rods offers a good solution for external strengthening of flexural reinforced concrete (RC) members. Limited data are available on the behavior of beams externally reinforced with CFRP rods under a loading–unloading protocol, which is of great importance for structural components subjected to vehicle loading. The embedment depth mandated by the majority of standards cannot always be acquired due to concrete cover limitations; the influence of embedment depth under this loading–unloading sequence needs to be investigated. This research studied the effects of rod embedment depth by comparing fully-embedded rods with half-embedded rods under a loading–unloading protocol and comparing the results with monotonic responses. An identical specimen without CFRP reinforcement functioned as the controlling element. The near-surface mounted technique (NSM) was used to integrate the rods with the concrete. The results show that CFRP rods positively affect the load-carrying capacity under a loading–unloading condition. The rods reduce the member’s ductility under monotonic loading but have no negative impact under loading–unloading. Whereas the difference in embedment depth configuration slightly affected the enhancement under monotonic loading, the half-embedded rods drastically reduced the capacity improvement under the loading–unloading sequence. An embedment depth deviating from the advised depth, should not be implemented for members subjected to a loading–unloading condition. The CFRP placement method had an impact on the failure behavior of the elements. The half-embedded rod failed by debonding between the rod and the epoxy resin, while the fully-embedded members were characterized by concrete spalling.
10.
Purwanto; Januarti Jaya Ekaputri; Nuroji; Bobby Rio Indriyantho; Aylie Han; Buntara Sthenly Gan
Shear-bond behavior of self-compacting geopolymer concrete to conventional concrete Journal Article
In: Construction and Building Materials, vol. 321, no. 126167, pp. 1-10, 2022.
@article{nokey,
title = {Shear-bond behavior of self-compacting geopolymer concrete to conventional concrete},
author = {Purwanto and Januarti Jaya Ekaputri and Nuroji and Bobby Rio Indriyantho and Aylie Han and Buntara Sthenly Gan},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0950061821038988},
doi = {https://doi.org/10.1016/j.conbuildmat.2021.126167},
year = {2022},
date = {2022-01-15},
journal = {Construction and Building Materials},
volume = {321},
number = {126167},
pages = {1-10},
abstract = {The shear-bond behavior of two mechanically different concretes is fundamental when conducting external reinforcement, retrofitting, or repair. The two components are designed to possess full strain compatibility in sustaining the stress transfer between the two parts throughout the loading sequence. This work investigated the shear-bond behavior between conventional and self-compacting geopolymer concrete based on the push-off method. The influence of surface roughness on the bond behavior was studied, and a finite element model was constructed and validated to the experimental data. Surprisingly, the chemical bond characteristics of geopolymer concrete have little effect on the bond strength as compared to conventional concrete having the same compression strengths, but significantly influences the load-slip pattern of the interface. As expected, the bond strength was positively influenced by the interface roughness. All failure modes were unmistakably brittle. The strain deformation pattern generated from the finite element model underlined that large strains and stresses were present at the far ends in the interface, where initial cracking was detected in these regions. The study concluded that self-compacting geopolymer concrete is a perfect solution for older structure’s external strengthening or retrofitting. This material has a better sustainable and a more environmentally friendly character.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The shear-bond behavior of two mechanically different concretes is fundamental when conducting external reinforcement, retrofitting, or repair. The two components are designed to possess full strain compatibility in sustaining the stress transfer between the two parts throughout the loading sequence. This work investigated the shear-bond behavior between conventional and self-compacting geopolymer concrete based on the push-off method. The influence of surface roughness on the bond behavior was studied, and a finite element model was constructed and validated to the experimental data. Surprisingly, the chemical bond characteristics of geopolymer concrete have little effect on the bond strength as compared to conventional concrete having the same compression strengths, but significantly influences the load-slip pattern of the interface. As expected, the bond strength was positively influenced by the interface roughness. All failure modes were unmistakably brittle. The strain deformation pattern generated from the finite element model underlined that large strains and stresses were present at the far ends in the interface, where initial cracking was detected in these regions. The study concluded that self-compacting geopolymer concrete is a perfect solution for older structure’s external strengthening or retrofitting. This material has a better sustainable and a more environmentally friendly character.