This paper explain the behavior of beam with the confinement hoops in compression zone subjected ... more This paper explain the behavior of beam with the confinement hoops in compression zone subjected to cyclic loading. The experimental study aims to determine the ductility and energy dissipation of beam with hoops confinement in compression zone at the plastic hinge region under cyclic loading. Two half-scale beam specimens that conducted as a simplification model of beam plastic hinge region at column face were tested. The one specimen was confined with hoops and would be compared by un-confinement beam in compression zone. The beam will be loaded with load centered on the middle of the span so it will receive the greatest moment and shear. The cyclic loading system by using displacement control with the static squasi loading gradually reaches the ultimate state. The experimental test shows that confining with hoops in the compression zone of beam's section increases up to 50 percent in displacement of ductility, and around 65 percent in curvature of ductility. Further, the cumulative index of energy dissipation of beam increase up to 2 times compared with un-confinement beam in compression zone. The confinement hoops of compression zone insignificant increase in terms of strength capacity and moments as well as in monotonic loading test.
Geopolymer concrete is a new material made by activating the raw materials which contain many ele... more Geopolymer concrete is a new material made by activating the raw materials which contain many elements of silica and alumina. Compressive strength of geopolymer concrete produced was influenced by the concentration of the activator solution. This paper presents an experimental investigation into fly ash-based geopolymer concrete. Research objective was to investigate the effects of alkaline activator solution (AAS) molarity on compressive strength of geopolymer concrete. Variable of the test were a solution to sodium hydroxide was chosen as the activator solution. Concentration of sodium hydroxide solution used was 10 M, 12 M and 14 M with ambient curing. The specimen is made of concrete cylinder with diameter 10 cm and height 20 cm as many as 9 pieces each variable. Compressive strength tests is performed when the concrete is 7, 14, and 28 days old. Results of the test are indicated that the increasing of sodium hydroxide (NaOH) solution concentration leads to improve the compressive strength of geopolymer concrete. The optimal compressive strength of geopolymer concrete was achieved at a concentration of sodium hydroxide solution (NaOH) of 12 M. Geopolymer concretes compressive strength only achieves around 50-60% of the planned.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
High seismicity rates in and around West Java and Sumatra occur as a result of the Indo-Australia... more High seismicity rates in and around West Java and Sumatra occur as a result of the Indo-Australian plate converging with and subducting beneath the Sunda plate. Large megathrust events associated with this process likely pose a major earthquake and tsunami hazard to the surrounding community, but further effort is required to help understand both the likelihood and frequency of such events. With this in mind, we exploit catalog seismic data sourced from the Agency for Meteorology, Climatology, and Geophysics (BMKG) of Indonesia and the International Seismological Centre (ISC) for the period April 2009 through to July 2020, in order to conduct earthquake hypocenter relocation using a teleseismic double-difference method. Our results reveal a large seismic gap to the south of West Java and southeast Sumatra, which is in agreement with a previous GPS study that finds the region to be a potential future source of megathrust earthquakes. To investigate this further, tsunami modeling was ...
The cyclic behaviour of plain cylindrical concrete subjected to multidirectional compression was ... more The cyclic behaviour of plain cylindrical concrete subjected to multidirectional compression was investigated experimentally. A total of 42 cylindrical concrete specimens from three different concrete mixes were tested. This test program was particularly focused on the strength and deformation aspects of the concrete response and the process of damage build-up. From this study, it was found that the most important response index for concrete subjected to cyclic loading was the history of damage accumulated in the microstructure which was measured in terms of volumetric strain. The degradation of the elastic stiflhess due to cyclic loads was found to be primarily a function of geometrical change and insensitive to the type of concrete considered. The comparison with the monotonic response of concrete which was also investigated in this study suggests that the cyclic nature of the load promotes damage build-up at faster rates than the monotonic loading, and the path-dependence in the ...
To accommodate increased seismic hazards in Indonesia, provisions regarding structural details on... more To accommodate increased seismic hazards in Indonesia, provisions regarding structural details on seismic regulations have been tightened. In this paper, the variations in seismic hazard and detailing requirements from bridge code era before 1990 to the present was provided. To examine the bridge performance, pushover analysis was carried out based on the latest bridge code SNI 2833:2016/Seismic Map 2017. From the analysis results, the performance of older bridges would typically be less than more recently designed structures. The performance level of the bridge in the era before SNI 2833:2016/Seismic Map 2017 will be Operational-Life Safety (LS) whereas the performance level of the bridge designed with SNI 2833:2016 will be Elastic – Operational. Referring to NCHRP 949 for bridge performance level evaluation, results show that the performance level of the bridge still satisfies the requirement, which is Life Safety under upper-level earthquake. Therefore, the existing bridge shows...
International Journal of Scientific & Technology Research, 2020
In the Indonesian and American codes of reinforced concrete design (SNI 2847:2013 and ACI 318-14,... more In the Indonesian and American codes of reinforced concrete design (SNI 2847:2013 and ACI 318-14, respectively) the Partial Prestressing Ratio (PPR) of a structure element is limited by 25 percent to prevent brittle behavior. Reactive Powder Concrete (RPC) materials provide high compression strength and ductility. The using of RPC allows increasing of PPR. Thus, the RPC structures provide higher nominal moment and ductility than normal concrete structures. The aim of this research was to examine the influence of PPR that exceeds 25 percent on partially pre-stressed beamcolumn joint sub-assemblages using RPC materials (PPRPC) to their performance. Three PPRPC specimens with PPR of 22.78 and 33.79 percent were tested according to ACI 374.1-05 loading set up. Furthermore, the finite element models of PPRPC were verified with the experiment results and also reinforced using PPR ranging from 22.78 to 41.12 percent. The results showed that the model using a PPR of 33.79 percent provided t...
IOP Conference Series: Materials Science and Engineering, 2016
Research on concrete material continues in several countries and had produced a concrete type of ... more Research on concrete material continues in several countries and had produced a concrete type of Ultra High Performance Concrete (UHPC) which has a better compressive strength, tensile strength, flexural strength, modulus of elasticity, and durability than normal concrete (NC) namely Reactive Powder Concrete (RPC). Researches on structures using RPC material showed that the RPC structures had a better performance than the NC structures in resisting gravity and lateral cyclic loads. In this study, an experiment was conducted to apply combination of constant axial and lateral cyclic loads to a prototype of RPC interior partial prestressed beam-column subassemblage (prototype of BCS-RPC) with a value of Partial Prestressed Ratio (PPR) of 31.72% on the beam. The test results were compared with finite element model of beam-column subassemblage made of RPC by PPR of 31.72% (BCS-RPC-31.72). Furthermore, there was BCS-RPC modeling with PPR of 21.39% (BCS-RPC-21.39) and beam-column subassemblages made of NC materials modeling with a value of PPR at 21.09% (BCS-NC-21.09) and 32.02% (BCS-NC-32.02). The purpose of this study was to determine the performance of the BCS-RPC models compared to the performance of the BCS-NC models with PPR values below and above 25%, which is the maximum limit of permitted PPR. The results showed that all models of BCS-RPC had a better performance than all models of BCS-NC and the BCS-RPC model with PPR above 25% still behaved ductile and was able to dissipate energy well.
Plastic hinge regions of beam needs special attention, especially in the face of the column while... more Plastic hinge regions of beam needs special attention, especially in the face of the column while receiving sizeable negative moment by both gravity and the added due to earthquake load. When an earthquake, the compression zone of beam’s section must hold the negative moments and great transverse force while usually compression concrete area is very small so prone to collapse. In this research it intended a more ductile structure elements in the plastic hinge region of beam by providing confinement in compression zone of beam’s section. An experimental investigation was conducted to examine the effect of confinement in the compression zone beam’s section in the plastic hinge that subjected to monotonic and cyclic loading. Six beam specimen with stub that describes the end of the beam – columns joint were prepared. Four specimens were given additional confinement in the compression zone in form of hoops or cross-ties, while the others were made as a beam without additional confinemen...
Journal of Advanced Civil and Environmental Engineering
Application of seismic isolation system is important in bridges design, primarily in seismically ... more Application of seismic isolation system is important in bridges design, primarily in seismically active countries. Bridges are prone to damage from seismic forces. Elastomeric isolation bearings have been applied in short-span bridges for some time in most countries. These bearings are preferred because of the low maintenance cost. However, these bearings are not reliable when subjected to large displacement and low temperatures. In the other hand, friction sliding bearings shows better performance under the former circumstances despite its use is still limited to long-span bridges and has not been explored further. This paper describes a performance evaluation of seismically-isolated short-span reinforced concrete bridge using friction pendulum system (FPS). Seismic performances of non-isolated and isolated models from the reference bridge functioning as light rapid transit (LRT) bridge in Jakarta are investigated using nonlinear time history analysis. The results demonstrate that ...
Seismically isolated bridges have shown better seismic performance than bridges with conventional... more Seismically isolated bridges have shown better seismic performance than bridges with conventional bearings during large earthquakes. While elastomeric type of isolation has been introduced in various new highway bridges in the country, the use of friction pendulum system for bridge bearing is not yet common in Indonesia, a highly seismically active country. In this paper, design and seismic performance evaluation of two typical reinforced concrete bridges seismically isolated by single concave friction pendulum (SCFP) bearings system and designed according to Indonesian seismic code is described. The reference bridges are selected from typical light rapid transit (LRT) bridge and highway reinforced concrete (RC) bridge in Indonesia. Seismic performances of SCFP-isolated bridges with different bearing configurations and the conventional non-isolated bridges under 1000-year design earthquake were investigated and compared using nonlinear finite element analyses. The results show that SCFP-isolated bridges performed better than non-isolated bridges under design earthquake as shown by reductions in the base shear force, absolute deck acceleration, and deck acceleration amplification ratio. Effects of SCFP on the seismic performance of isolated bridge was evaluated by comparing the moment and rotation values of each pier and the possible formation of plastic hinges. Performance comparisons of SCFPisolated bridges with various friction types and arrangements revealed that the LRT bridge with all higher friction and the highway bridge with lower friction have the best seismic performance among all isolated bridge models analyzed.
Geopolymer concrete is an environmentally friendly construction material that has the potential t... more Geopolymer concrete is an environmentally friendly construction material that has the potential to be applied in building structures. It is important to understand the structural behavior of geopolymer concrete. This paper presents an experimental investigation into the performance of structural elements of geopolymer concrete under concentric axial loads. The specimens were twelve square columns with a size of 170 x 170 mm and a height of 480 mm. The study variables were the tie spacing and the compressive strength of unconfined geopolymer concrete (f’c). The test results showed that the increase in f'cc was not as significant as the increase in unconfined concrete compressive strength (f'c). The value of strength enhancement (K) tended to decrease. The column ductility (m) and confinement effectiveness index (Ic) had optimum values. The effect of increasing the tie spacing (s) decreased the K, Ic, and m values of the column. The proposed f’cc formulation for geopolymer con...
This paper explain the behavior of beam with the confinement hoops in compression zone subjected ... more This paper explain the behavior of beam with the confinement hoops in compression zone subjected to cyclic loading. The experimental study aims to determine the ductility and energy dissipation of beam with hoops confinement in compression zone at the plastic hinge region under cyclic loading. Two half-scale beam specimens that conducted as a simplification model of beam plastic hinge region at column face were tested. The one specimen was confined with hoops and would be compared by un-confinement beam in compression zone. The beam will be loaded with load centered on the middle of the span so it will receive the greatest moment and shear. The cyclic loading system by using displacement control with the static squasi loading gradually reaches the ultimate state. The experimental test shows that confining with hoops in the compression zone of beam's section increases up to 50 percent in displacement of ductility, and around 65 percent in curvature of ductility. Further, the cumulative index of energy dissipation of beam increase up to 2 times compared with un-confinement beam in compression zone. The confinement hoops of compression zone insignificant increase in terms of strength capacity and moments as well as in monotonic loading test.
Geopolymer concrete is a new material made by activating the raw materials which contain many ele... more Geopolymer concrete is a new material made by activating the raw materials which contain many elements of silica and alumina. Compressive strength of geopolymer concrete produced was influenced by the concentration of the activator solution. This paper presents an experimental investigation into fly ash-based geopolymer concrete. Research objective was to investigate the effects of alkaline activator solution (AAS) molarity on compressive strength of geopolymer concrete. Variable of the test were a solution to sodium hydroxide was chosen as the activator solution. Concentration of sodium hydroxide solution used was 10 M, 12 M and 14 M with ambient curing. The specimen is made of concrete cylinder with diameter 10 cm and height 20 cm as many as 9 pieces each variable. Compressive strength tests is performed when the concrete is 7, 14, and 28 days old. Results of the test are indicated that the increasing of sodium hydroxide (NaOH) solution concentration leads to improve the compressive strength of geopolymer concrete. The optimal compressive strength of geopolymer concrete was achieved at a concentration of sodium hydroxide solution (NaOH) of 12 M. Geopolymer concretes compressive strength only achieves around 50-60% of the planned.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
High seismicity rates in and around West Java and Sumatra occur as a result of the Indo-Australia... more High seismicity rates in and around West Java and Sumatra occur as a result of the Indo-Australian plate converging with and subducting beneath the Sunda plate. Large megathrust events associated with this process likely pose a major earthquake and tsunami hazard to the surrounding community, but further effort is required to help understand both the likelihood and frequency of such events. With this in mind, we exploit catalog seismic data sourced from the Agency for Meteorology, Climatology, and Geophysics (BMKG) of Indonesia and the International Seismological Centre (ISC) for the period April 2009 through to July 2020, in order to conduct earthquake hypocenter relocation using a teleseismic double-difference method. Our results reveal a large seismic gap to the south of West Java and southeast Sumatra, which is in agreement with a previous GPS study that finds the region to be a potential future source of megathrust earthquakes. To investigate this further, tsunami modeling was ...
The cyclic behaviour of plain cylindrical concrete subjected to multidirectional compression was ... more The cyclic behaviour of plain cylindrical concrete subjected to multidirectional compression was investigated experimentally. A total of 42 cylindrical concrete specimens from three different concrete mixes were tested. This test program was particularly focused on the strength and deformation aspects of the concrete response and the process of damage build-up. From this study, it was found that the most important response index for concrete subjected to cyclic loading was the history of damage accumulated in the microstructure which was measured in terms of volumetric strain. The degradation of the elastic stiflhess due to cyclic loads was found to be primarily a function of geometrical change and insensitive to the type of concrete considered. The comparison with the monotonic response of concrete which was also investigated in this study suggests that the cyclic nature of the load promotes damage build-up at faster rates than the monotonic loading, and the path-dependence in the ...
To accommodate increased seismic hazards in Indonesia, provisions regarding structural details on... more To accommodate increased seismic hazards in Indonesia, provisions regarding structural details on seismic regulations have been tightened. In this paper, the variations in seismic hazard and detailing requirements from bridge code era before 1990 to the present was provided. To examine the bridge performance, pushover analysis was carried out based on the latest bridge code SNI 2833:2016/Seismic Map 2017. From the analysis results, the performance of older bridges would typically be less than more recently designed structures. The performance level of the bridge in the era before SNI 2833:2016/Seismic Map 2017 will be Operational-Life Safety (LS) whereas the performance level of the bridge designed with SNI 2833:2016 will be Elastic – Operational. Referring to NCHRP 949 for bridge performance level evaluation, results show that the performance level of the bridge still satisfies the requirement, which is Life Safety under upper-level earthquake. Therefore, the existing bridge shows...
International Journal of Scientific & Technology Research, 2020
In the Indonesian and American codes of reinforced concrete design (SNI 2847:2013 and ACI 318-14,... more In the Indonesian and American codes of reinforced concrete design (SNI 2847:2013 and ACI 318-14, respectively) the Partial Prestressing Ratio (PPR) of a structure element is limited by 25 percent to prevent brittle behavior. Reactive Powder Concrete (RPC) materials provide high compression strength and ductility. The using of RPC allows increasing of PPR. Thus, the RPC structures provide higher nominal moment and ductility than normal concrete structures. The aim of this research was to examine the influence of PPR that exceeds 25 percent on partially pre-stressed beamcolumn joint sub-assemblages using RPC materials (PPRPC) to their performance. Three PPRPC specimens with PPR of 22.78 and 33.79 percent were tested according to ACI 374.1-05 loading set up. Furthermore, the finite element models of PPRPC were verified with the experiment results and also reinforced using PPR ranging from 22.78 to 41.12 percent. The results showed that the model using a PPR of 33.79 percent provided t...
IOP Conference Series: Materials Science and Engineering, 2016
Research on concrete material continues in several countries and had produced a concrete type of ... more Research on concrete material continues in several countries and had produced a concrete type of Ultra High Performance Concrete (UHPC) which has a better compressive strength, tensile strength, flexural strength, modulus of elasticity, and durability than normal concrete (NC) namely Reactive Powder Concrete (RPC). Researches on structures using RPC material showed that the RPC structures had a better performance than the NC structures in resisting gravity and lateral cyclic loads. In this study, an experiment was conducted to apply combination of constant axial and lateral cyclic loads to a prototype of RPC interior partial prestressed beam-column subassemblage (prototype of BCS-RPC) with a value of Partial Prestressed Ratio (PPR) of 31.72% on the beam. The test results were compared with finite element model of beam-column subassemblage made of RPC by PPR of 31.72% (BCS-RPC-31.72). Furthermore, there was BCS-RPC modeling with PPR of 21.39% (BCS-RPC-21.39) and beam-column subassemblages made of NC materials modeling with a value of PPR at 21.09% (BCS-NC-21.09) and 32.02% (BCS-NC-32.02). The purpose of this study was to determine the performance of the BCS-RPC models compared to the performance of the BCS-NC models with PPR values below and above 25%, which is the maximum limit of permitted PPR. The results showed that all models of BCS-RPC had a better performance than all models of BCS-NC and the BCS-RPC model with PPR above 25% still behaved ductile and was able to dissipate energy well.
Plastic hinge regions of beam needs special attention, especially in the face of the column while... more Plastic hinge regions of beam needs special attention, especially in the face of the column while receiving sizeable negative moment by both gravity and the added due to earthquake load. When an earthquake, the compression zone of beam’s section must hold the negative moments and great transverse force while usually compression concrete area is very small so prone to collapse. In this research it intended a more ductile structure elements in the plastic hinge region of beam by providing confinement in compression zone of beam’s section. An experimental investigation was conducted to examine the effect of confinement in the compression zone beam’s section in the plastic hinge that subjected to monotonic and cyclic loading. Six beam specimen with stub that describes the end of the beam – columns joint were prepared. Four specimens were given additional confinement in the compression zone in form of hoops or cross-ties, while the others were made as a beam without additional confinemen...
Journal of Advanced Civil and Environmental Engineering
Application of seismic isolation system is important in bridges design, primarily in seismically ... more Application of seismic isolation system is important in bridges design, primarily in seismically active countries. Bridges are prone to damage from seismic forces. Elastomeric isolation bearings have been applied in short-span bridges for some time in most countries. These bearings are preferred because of the low maintenance cost. However, these bearings are not reliable when subjected to large displacement and low temperatures. In the other hand, friction sliding bearings shows better performance under the former circumstances despite its use is still limited to long-span bridges and has not been explored further. This paper describes a performance evaluation of seismically-isolated short-span reinforced concrete bridge using friction pendulum system (FPS). Seismic performances of non-isolated and isolated models from the reference bridge functioning as light rapid transit (LRT) bridge in Jakarta are investigated using nonlinear time history analysis. The results demonstrate that ...
Seismically isolated bridges have shown better seismic performance than bridges with conventional... more Seismically isolated bridges have shown better seismic performance than bridges with conventional bearings during large earthquakes. While elastomeric type of isolation has been introduced in various new highway bridges in the country, the use of friction pendulum system for bridge bearing is not yet common in Indonesia, a highly seismically active country. In this paper, design and seismic performance evaluation of two typical reinforced concrete bridges seismically isolated by single concave friction pendulum (SCFP) bearings system and designed according to Indonesian seismic code is described. The reference bridges are selected from typical light rapid transit (LRT) bridge and highway reinforced concrete (RC) bridge in Indonesia. Seismic performances of SCFP-isolated bridges with different bearing configurations and the conventional non-isolated bridges under 1000-year design earthquake were investigated and compared using nonlinear finite element analyses. The results show that SCFP-isolated bridges performed better than non-isolated bridges under design earthquake as shown by reductions in the base shear force, absolute deck acceleration, and deck acceleration amplification ratio. Effects of SCFP on the seismic performance of isolated bridge was evaluated by comparing the moment and rotation values of each pier and the possible formation of plastic hinges. Performance comparisons of SCFPisolated bridges with various friction types and arrangements revealed that the LRT bridge with all higher friction and the highway bridge with lower friction have the best seismic performance among all isolated bridge models analyzed.
Geopolymer concrete is an environmentally friendly construction material that has the potential t... more Geopolymer concrete is an environmentally friendly construction material that has the potential to be applied in building structures. It is important to understand the structural behavior of geopolymer concrete. This paper presents an experimental investigation into the performance of structural elements of geopolymer concrete under concentric axial loads. The specimens were twelve square columns with a size of 170 x 170 mm and a height of 480 mm. The study variables were the tie spacing and the compressive strength of unconfined geopolymer concrete (f’c). The test results showed that the increase in f'cc was not as significant as the increase in unconfined concrete compressive strength (f'c). The value of strength enhancement (K) tended to decrease. The column ductility (m) and confinement effectiveness index (Ic) had optimum values. The effect of increasing the tie spacing (s) decreased the K, Ic, and m values of the column. The proposed f’cc formulation for geopolymer con...
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